Does minimally invasive coronary artery bypass improve outcomes compared to off-pump coronary bypass via sternotomy in patients undergoing coronary artery bypass grafting?

Does minimally invasive coronary artery bypass improve outcomes compared to off-pump coronary... Abstract A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘In patients undergoing off-pump coronary artery bypass grafting, for single or multivessel disease, does minimally invasive direct coronary artery bypass (MIDCAB) or off-pump coronary artery bypass (OPCAB) provide the superior outcome including a reduction in morbidity and mortality?’. A total of 187 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, date, journal and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. It was found that compared to OPCAB, MIDCAB surgery can offer decreased intensive care unit length of stay (4.5–57.4 h vs 5.2–52.7 h) and total hospital length of stay (4.5–8.5 days vs 5.2–12 days), with 1 paper showing a decrease in mortality at 1 year (3% vs 14%). However, there were several papers that showed significant risks with MIDCAB surgery in patients with either single or multivessel disease. These include increased risk of incomplete revascularization (29% vs 0%), significant early complications (22.5 vs 0%), urgent reintervention (16% vs 0%), repeat revascularization events (12.2% vs 3.7%), progression of native disease (4.8% vs 0.9%), rehospitalization by 3 months (20% vs 2%) and postoperative infarction (2.9% vs 1.45%). These risks did not translate to an increase in early mortality (0–1% vs 0–1.6%) or late mortality (0–3% vs 0–14%) in papers that included mid-term follow up. However, they do represent significant potential risks that cannot be overlooked when considering the use of MIDCAB. We conclude that MIDCAB is associated with greater morbidity and reintervention compared to OPCAB via sternotomy, but both techniques are equivalent in terms of operative and mid-term mortality. Off-pump coronary artery bypass, Minimally invasive direct coronary artery bypass, thoraCAB, Coronary artery bypass grafting, Minimally invasive cardiac surgery INTRODUCTION A best evidence topic was constructed according to a structured protocol. This is fully described in the ICVTS [1]. THREE-PART QUESTION In [patients undergoing off-pump coronary artery bypass grafting for single and multivessel disease] does [minimally invasive direct coronary artery bypass (MIDCAB) or off-pump coronary artery bypass (OPCAB)] provide superior outcome in terms of [morbidity and mortality]. CLINICAL SCENARIO A 60-year-old man is admitted to the cardiology unit with an isolated bifurcation lesion in the left anterior descending artery. You plan to offer the patient MIDCAB, but your colleague suggests the outcomes are not as good as with OPCAB via sternotomy. You review the literature to resolve the debate. SEARCH STRATEGY MEDLINE was searched from 1950 to October 2017 using the OVID interface: [opcab.mp OR off pump coronary bypass.mp OR off pump cabg.mp] and [midcab.mp OR minimally invasive coronary artery bypass.mp OR minimally invasive cabg OR thoracab.mp OR minimally invasive.mp]. SEARCH OUTCOME A total of 187 papers were found using the reported search. From these, 12 papers were identified that provided the best evidence to answer the question. These are presented in Table 1. Of the 12 papers identified, 8 were published in the last decade with the remaining being published between 1999 and 2003. Table 1: Best evidence papers Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   AF: atrial fibrillation; BET: best evidence topic; CABG: coronary artery bypass grafting; CCF: congestive cardiac failure; CCS: Canadian Cardiovascular Society; CK-MB: creatine kinase myocardial band; CPB: cardiopulmonary bypass; CRP: C-reactive protein; cTnI: cardiac troponin 1; CVA: cardiovascular accident; DC: discharge; FVC: forced vital capacity; HCR: hybrid coronary revascularization; ICC: intercostal catheter; ICU: intensive care unit; IMA: internal mammary artery; LAD: left anterior descending artery; LCx: left circumflex artery; LIMA: left internal mammary artery; LITA: left internal thoracic artery; LOS: length of stay; LVEF: left ventricular ejection fraction; MACCE: major adverse cardiac and cerebrovascular event; MI: myocardial infarction; MIDCAB: minimally invasive coronary artery bypass; MICS: minimally invasive cardiac surgery; OPCAB: off-pump coronary artery bypass; NA: not applicable; ns: not significant; PCI: percutaneous coronary intervention; pro-BNP: pro-brain natriuretic peptide; RBC: red blood cells; RCA: right coronary artery; SHR: staged hybrid revascularization; SV: saphenous vein. Table 1: Best evidence papers Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   AF: atrial fibrillation; BET: best evidence topic; CABG: coronary artery bypass grafting; CCF: congestive cardiac failure; CCS: Canadian Cardiovascular Society; CK-MB: creatine kinase myocardial band; CPB: cardiopulmonary bypass; CRP: C-reactive protein; cTnI: cardiac troponin 1; CVA: cardiovascular accident; DC: discharge; FVC: forced vital capacity; HCR: hybrid coronary revascularization; ICC: intercostal catheter; ICU: intensive care unit; IMA: internal mammary artery; LAD: left anterior descending artery; LCx: left circumflex artery; LIMA: left internal mammary artery; LITA: left internal thoracic artery; LOS: length of stay; LVEF: left ventricular ejection fraction; MACCE: major adverse cardiac and cerebrovascular event; MI: myocardial infarction; MIDCAB: minimally invasive coronary artery bypass; MICS: minimally invasive cardiac surgery; OPCAB: off-pump coronary artery bypass; NA: not applicable; ns: not significant; PCI: percutaneous coronary intervention; pro-BNP: pro-brain natriuretic peptide; RBC: red blood cells; RCA: right coronary artery; SHR: staged hybrid revascularization; SV: saphenous vein. RESULTS There were 3 papers that compared patients with predominantly single-vessel disease. The first of which by Karpazoglu et al. [2] compared outcomes from 54 patients with single-vessel disease treated with MIDCAB or OPCAB, with 27 patients in each group. The authors found no difference in mortality, reoperation, gastrointestinal bleeding, atrial fibrillation (AF), mortality, myocardial infarction (MI), stroke, surgical site infection (SSI) or intensive care unit (ICU) length of stay (LOS). The total hospital LOS was, however, lower (4.5 ± 0.7 vs 5.2 ± 1.4 days; P = 0.03). Detter et al. [3] compared outcomes from 129 MIDCAB and 127 OPCAB patients, all with single-vessel disease. No difference was observed in the rate of conversion to cardiopulmonary bypass, reoperation for bleeding or graft failure, SSI, cerebrovascular accident, MI, mortality, ICU or hospital LOS. Postoperative angiography (7.4 ± 5.8 days) showed no difference in the rates of graft patency, stenoses >50% or reoperation for graft failure. Vicol et al. [4] compared 57 MIDCAB patients with single-vessel disease with 45 OPCAB patients, 37.8% of whom also received a vein graft to a diagonal branch. No difference was observed in ICU LOS, mortality, MI, wound infection, renal failure, neurological complications or reoperation for bleeding. The rate of urgent reintervention was higher in the MIDCAB group (16% vs 0%, P = 0.023). At late follow-up, there was no difference in recurrent angina, MI, reintervention or mortality. Four papers compared patients with multivessel disease who were treated with OPCAB or MIDCAB plus staged hybrid revascularization or hybrid coronary revascularization. Yang et al. [5] randomized 63 patients to MIDCAB/hybrid coronary revascularization surgery and 63 to OPCAB surgery. No difference was observed in hospital LOS or congestive cardiac failure at 1 year. Mortality at 1 year was lower in the MIDCAB group (3% vs 14%, P = 0.003). Zhang et al. [6] compared 300 MIDCAB/staged hybrid revascularization patients with 355 OPCAB patients. No significant difference was observed in re-exploration for bleeding, postoperative MI, SSI or 30-day mortality. The ICU LOS was lower in the MIDCAB group (24.27 ± 17.25 vs 59.13 ± 60.39 h, P< 0.001). Birla et al. [7] compared matched patients, of whom 74 had MIDCAB/staged hybrid revascularization and 78 OPCAB. No difference was observed in the rates of reoperation, SSI, AF, cerebrovascular events or mortality. At late postoperative follow–up, there was no difference in the rates of reoperation, SSI, AF, cerebrovascular events or mortality. At late postoperative follow–up, there was no difference in recurrent MI, angina, cerebrovascular events, ‘redo’ percutaneous coronary intervention or coronary artery bypass grafting. A reduced hospital LOS was observed in the MIDCAB group (6.1 vs 8.2 days, P < 0.05). Halkos et al. [8] compared 147 MIDCAB/hybrid coronary revascularization patients who were matched (optimal matching) 1:4 with 588 OPCAB patients. No difference was observed in early mortality, MI, stroke, renal failure, AF or major adverse cardiac and cerebrovascular events. A significantly increased number of repeat revascularization events (12.2% vs 3.7%, P < 0.001), target vessel revascularization (8.8% vs 3.1%, P = 0.002), progression of native disease (4.8% vs 0.9%, P < 0.001) and internal mammary artery/internal mammary artery–left anterior descending artery lesions (4.8% vs 1%, P < 0.001) in the MIDCAB group was noted; however, there was no difference in 5-year survival. Two papers compared patients with multivessel disease who were treated with MIDCAB/thoraCAB or OPCAB, where in either of the operations, multiple anastomoses were made. In a randomized controlled trial by Rogers et al. [9] of 191 patients, 95 were randomized to thoraCAB and 96 to OPCAB. No difference was observed in hospital LOS, ICU LOS, postoperative arrhythmias, MI, cardiac arrest, pulmonary complications, SSI or mortality. The authors did find differences in lung function at discharge with patients in the MIDCAB group showing a lower forced vital capacity (1.90 l vs 2.15 l, P = 0.01). Gersbach et al. [10] also compared patients with multivessel disease, 31 of whom underwent MIDCAB and 39 OPCAB. More significant early complications (22.5% vs 0%, P < 0.01), wound issues (37% vs 13%, P < 0.05), rehospitalization by 3 months (20% vs 2%, P < 0.05) and less complete revascularization (29% vs 0%, P < 0.01) were observed in the MIDCAB group. Mortality, residual angina, dyspnoea and pleural effusion were comparable at 3 months. One large meta-analysis was reviewed in which there was no differentiation between single- or multivessel disease. Stanbridge et al. [11] compared 3304 MIDCAB patients with 3060 OPCAB patients. The 5-year survival and mortality rate were the same; however, graft stenosis and occlusion were higher in the MIDCAB group (10.5% vs 6.4%, P = 0.08). A reduction in the combined stenosis rate (16–5%, P < 0.0001) after the utilization of myocardial stabilization was noted. However, this had no impact on mortality or MI rate. Two papers reviewed outcomes of minimally invasive coronary surgery (MICS) in patients with multivessel disease. The first of which by Lapierre et al. [12] compared 150 MICS patients with 150 OPCAB patients from a single surgeon and from the same time period. The OPCAB patients were randomly matched for age, gender, left ventricular function and median number of distal anastomoses from a possible 312 OPCAB patients. No difference was observed in the rate of reoperation, stroke, respiratory insufficiency, renal failure, AF, mortality or perioperative percutaneous coronary intervention. A shorter hospital LOS (5 vs 6 days, P = 0.02), lower incidence of deep wound infection (0% vs 4%, P = 0.03) and shorter median time to return to full activity (12 vs 34 days, P < 0.001) in the MICS group was noted. Complete revascularization was achieved in both groups. In this study, 28 patients in the MICS group underwent cardiopulmonary bypass via femoral venous and arterial cannulation. Ruel et al. [13] investigated the outcomes of 89 patients who underwent MICS and had angiographic follow-up at 6 months. No patient in this study had incomplete revascularization, and 6-month follow up showed 100% graft patency in left internal thoracic artery grafts and 85% patency in saphenous vein (SV). There was no difference in postoperative aortic complications, MI, cerebrovascular accident or mortality (0 vs 0, P = ns). CLINICAL BOTTOM LINE MIDCAB and OPCAB are similar in terms of early and mid-term mortality. However, the minimally invasive approach is associated with greater risk of incomplete revascularization, graft occlusion and repeat revascularization than OPCAB via sternotomy. Conflict of interest: none declared. REFERENCES 1 Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact CardioVasc Thorac Surg  2003; 2: 405– 9. Google Scholar CrossRef Search ADS PubMed  2 Karpuzoglu OE, Ozay B, Sener T, Aydin NB, Ketenci B, Aksu T et al.   Comparison of minimally invasive direct coronary artery bypass and off-pump coronary artery bypass in single-vessel disease. Heart Surg Forum  2009; 12: E39– 43. Google Scholar CrossRef Search ADS PubMed  3 Detter C, Reichenspurner H, Boehm DH, Thalhammer M, Schütz A, Reichart B. Single vessel revascularization with beating heart techniques—minithoracotomy or sternotomy? Eur J Cardiothorac Surg  2001; 19: 464– 70. Google Scholar CrossRef Search ADS PubMed  4 Vicol C, Nollert G, Mair H, Samuel V, Lim C, Tiftikidis M et al.   Midterm results of beating heart surgery in 1-vessel disease: minimally invasive direct coronary artery bypass versus off-pump coronary artery bypass with full sternotomy. Heart Surg Forum  2003; 6: 341– 44. Google Scholar PubMed  5 Yang M, Xiao LB, Gao ZH, Zhou JW. Clinical effect and prognosis of off-pump minimally invasive direct coronary artery bypass. Med Sci Monit  2017; 23: 1123– 8. Google Scholar CrossRef Search ADS PubMed  6 Zhang L, Cui Z, Song Z, Yang H, Fu Y, Gong Y et al.   Minimally invasive direct coronary artery bypass for left anterior descending artery revascularisation—analysis of 300 cases. Videosurgery Miniinv  2015; 10: 548– 54. 7 Birla B, Patel P, Aresu G, Asimakopoulos G. Minimally invasive direct coronary artery bypass versus off-pump coronary surgery through sternotomy. Ann R Coll Surg Engl  2013; 95: 481– 5. Google Scholar CrossRef Search ADS PubMed  8 Halkos ME, Vassiliades TA, Douglas JS, Morris DC, Rab T, Liberman HA et al.   Hybrid coronary revascularization versus off-pump coronary artery bypass grafting for the treatment of multivessel coronary artery disease. Ann Thorac Surg  2011; 92: 1695– 702. Google Scholar CrossRef Search ADS PubMed  9 Rogers CA, Pike K, Angelini GD, Reeves BC, Glauber M, Ferrarini M et al.   An open randomised control trial of median sternotomy versus anterolateral left thoracotomy on morbidity and health care resource use in patients having off-pump coronary artery bypass surgery: the sternotomy versus thoracotomy (STET) trial. J Thorac Cardiovasc Surg  2013; 146: 306– 16. Google Scholar CrossRef Search ADS PubMed  10 Gersbach P, Imsand C, von Segesser LK, Delabays A, Vogt P, Stumpe F. Beating heart coronary artery surgery: is sternotomy a suitable alternative to minimally invasive technique? Eur J Cardiothorac Surg  2001; 20: 760– 4. Google Scholar CrossRef Search ADS PubMed  11 Stanbridge RDL, Hadjinikolaou LK. Technical adjuncts in beating heart surgery comparison of MIDCAB to off-pump sternotomy: a meta-analysis. Eur J Cardiothorac Surg  1999; 16: 24– 33. 12 Lapierre H, Chan V, Sohmer B, Mesana TG, Ruel M. Minimally invasive coronary artery bypass graft via small thoracotomy off-pump: a case-matched study. Eur J Cardiothorac Surg  2011; 40: 804– 10. Google Scholar PubMed  13 Ruel M, Shariff MA, Lapierre H, Goyal N, Dennie C, Sadel SM et al.   Results of the minimally invasive coronary artery bypass grafting angiographic patency study. J Thorac Cardiovasc Surg  2014; 147: 203– 9. Google Scholar CrossRef Search ADS PubMed  © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Interactive CardioVascular and Thoracic Surgery Oxford University Press

Does minimally invasive coronary artery bypass improve outcomes compared to off-pump coronary bypass via sternotomy in patients undergoing coronary artery bypass grafting?

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Oxford University Press
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© The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
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1569-9293
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1569-9285
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10.1093/icvts/ivy071
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Abstract

Abstract A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘In patients undergoing off-pump coronary artery bypass grafting, for single or multivessel disease, does minimally invasive direct coronary artery bypass (MIDCAB) or off-pump coronary artery bypass (OPCAB) provide the superior outcome including a reduction in morbidity and mortality?’. A total of 187 papers were found using the reported search, of which 12 represented the best evidence to answer the clinical question. The authors, date, journal and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. It was found that compared to OPCAB, MIDCAB surgery can offer decreased intensive care unit length of stay (4.5–57.4 h vs 5.2–52.7 h) and total hospital length of stay (4.5–8.5 days vs 5.2–12 days), with 1 paper showing a decrease in mortality at 1 year (3% vs 14%). However, there were several papers that showed significant risks with MIDCAB surgery in patients with either single or multivessel disease. These include increased risk of incomplete revascularization (29% vs 0%), significant early complications (22.5 vs 0%), urgent reintervention (16% vs 0%), repeat revascularization events (12.2% vs 3.7%), progression of native disease (4.8% vs 0.9%), rehospitalization by 3 months (20% vs 2%) and postoperative infarction (2.9% vs 1.45%). These risks did not translate to an increase in early mortality (0–1% vs 0–1.6%) or late mortality (0–3% vs 0–14%) in papers that included mid-term follow up. However, they do represent significant potential risks that cannot be overlooked when considering the use of MIDCAB. We conclude that MIDCAB is associated with greater morbidity and reintervention compared to OPCAB via sternotomy, but both techniques are equivalent in terms of operative and mid-term mortality. Off-pump coronary artery bypass, Minimally invasive direct coronary artery bypass, thoraCAB, Coronary artery bypass grafting, Minimally invasive cardiac surgery INTRODUCTION A best evidence topic was constructed according to a structured protocol. This is fully described in the ICVTS [1]. THREE-PART QUESTION In [patients undergoing off-pump coronary artery bypass grafting for single and multivessel disease] does [minimally invasive direct coronary artery bypass (MIDCAB) or off-pump coronary artery bypass (OPCAB)] provide superior outcome in terms of [morbidity and mortality]. CLINICAL SCENARIO A 60-year-old man is admitted to the cardiology unit with an isolated bifurcation lesion in the left anterior descending artery. You plan to offer the patient MIDCAB, but your colleague suggests the outcomes are not as good as with OPCAB via sternotomy. You review the literature to resolve the debate. SEARCH STRATEGY MEDLINE was searched from 1950 to October 2017 using the OVID interface: [opcab.mp OR off pump coronary bypass.mp OR off pump cabg.mp] and [midcab.mp OR minimally invasive coronary artery bypass.mp OR minimally invasive cabg OR thoracab.mp OR minimally invasive.mp]. SEARCH OUTCOME A total of 187 papers were found using the reported search. From these, 12 papers were identified that provided the best evidence to answer the question. These are presented in Table 1. Of the 12 papers identified, 8 were published in the last decade with the remaining being published between 1999 and 2003. Table 1: Best evidence papers Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   AF: atrial fibrillation; BET: best evidence topic; CABG: coronary artery bypass grafting; CCF: congestive cardiac failure; CCS: Canadian Cardiovascular Society; CK-MB: creatine kinase myocardial band; CPB: cardiopulmonary bypass; CRP: C-reactive protein; cTnI: cardiac troponin 1; CVA: cardiovascular accident; DC: discharge; FVC: forced vital capacity; HCR: hybrid coronary revascularization; ICC: intercostal catheter; ICU: intensive care unit; IMA: internal mammary artery; LAD: left anterior descending artery; LCx: left circumflex artery; LIMA: left internal mammary artery; LITA: left internal thoracic artery; LOS: length of stay; LVEF: left ventricular ejection fraction; MACCE: major adverse cardiac and cerebrovascular event; MI: myocardial infarction; MIDCAB: minimally invasive coronary artery bypass; MICS: minimally invasive cardiac surgery; OPCAB: off-pump coronary artery bypass; NA: not applicable; ns: not significant; PCI: percutaneous coronary intervention; pro-BNP: pro-brain natriuretic peptide; RBC: red blood cells; RCA: right coronary artery; SHR: staged hybrid revascularization; SV: saphenous vein. Table 1: Best evidence papers Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   Author, date, journal and country Study type (level of evidence)  Patient group  Outcomes  Key results (MIDCAB vs OPCAB)  Comments  Karpazoglu et al. (2009) Heart Surg Forum, Turkey [2] Retrospective cohort (level III)  27 MIDCAB 27 OPCAB Single-vessel disease only  Mortality (%)  0 vs 0   Smallest series in this BET   Duration of mechanical ventilation (h)  6.8 ± 3.0 vs 8.3 ± 1.6 (P = 0.028)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Bleeding (ml)  547 ± 391 vs 696  ± 198 (P = ns)   Postoperative day 1 CK-MB (U/l)  32.9 ± 16 vs 36.30 ± 27.6 (P = ns)   Reoperation (%)  11.1 vs 0 (P = ns)   Blood transfusion (U)  0.9 ± 1.2 vs 0.74 ± 0.9 (P = ns)   Gastrointestinal bleeding (%)  0 vs 0 (P = ns)   AF (%)  7.4 vs 7.4 (P = ns)   Surgical site infection (%)  7.4 vs 0 (P = ns)   MI (%)  0 vs 0 (P = ns)   Stroke (%)  0 vs 0 (P = ns)   ICU stay (h)  21.56 ± 2.37 vs 23.11 ± 1.62 (P = ns)   Total hospital stay (days)  4.5 ± 0.7 vs 5.2 ± 1.4 (P = 0.03)     Detter et al. (2001), Eur J Cardiothorac Surg, Germany [3] Retrospective cohort (level III)  129 MIDCAB 127 OPCAB MIDCAB—single-vessel disease OPCAB—multivessel disease  Conversion to CPB (%)  3.9 vs 0.8 (P = ns)   Very early angiographic follow-up (7.4 ± 5.8 days) Difference in preoperative demographic data—OPCAB patients significantly older, with higher CCS classification, a lower LVEF and higher rate of unfavourable anatomy  Time of surgery (min)  148 ± 59 vs 116 ± 46 (P = 0.028)   Coronary artery occlusion time (min)  20.2 ± 6.9 vs 15.9 ± 7.3 (P = 0.009)   Ventilation time (h)  6.5 ± 3.4 vs 8.2 ± 5.6 (P = ns)   ICU stay (h)  22.7 ± 6.7 vs 27.0 ± 12.2 (P = ns)   Hospital stay (days)  8.5 ± 3.9 vs 9.2 ± 6.2 (P = ns)   Blood loss (ml)  482 ± 311 vs 896 ± 342 (P = 0.006)   Reoperation for bleeding (%)  2.3 vs 3.1 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)   Hospital mortality (%)  0 vs 1.5 (P = ns)   Wound infection (%)  4.7 vs 0.8 (P = ns)       MI (%)  4.7 vs 1.6 (P = ns)         Cerebrovascular accident (%)  0 vs 0 (P = ns)         Postoperative angiography (7.4 ± 5.8 days postoperatively)        Angiography rate (%)  43 vs 37 (P = ns)     Stenosis >50% (%)  7 vs 6 (P = ns)   Graft patency rate (%)  96 vs 98 (P = ns)   Reoperation for graft failure (%)  2.3 vs 1.6 (P = ns)    Vicol et al. (2003), Heart Surg Forum, Germany [4] Retrospective cohort (level III)  58 MIDCAB 44 OPCAB Patients in MIDCAB group had single-vessel disease 37.5% of OPCAB patients received additional vein graft to diagonal branch  Operation time (min)  197 ± 45 vs 169 ± 48 (P = 0.004)   Mean follow-up at 5.2 years 12-surgeon experience with varying levels of expertise  Conversion to CPB (%)  2 vs NA (P = ns)   Anastomosis time (min)  23 ± 6 vs 19 ± 7 (P = 0.009)   Time on ventilator (h)  29 ± 109 vs 10 ± 6 (P = ns)   Time in ICU (h)  57 ± 129 vs 32 ± 14 (P = ns)   Perioperative mortality (%)  0 vs 0 (P = ns)   MI (%)  3 vs 2 (P = ns)   Wound infection (%)  5 vs 0 (P = ns)   Renal failure (%)  0 vs 0 (P = ns)   Neurological complication (%)  0 vs 0 (P = ns)   Urgent reintervention (%)  16 vs 0 (P = 0.023)   Reoperation for bleeding (%)  1.7 vs 2.3 (P = ns)   Recurrent angina at late follow-up (%)   40 vs 27 (P = ns)   New MI at late follow-up (%)  7 vs 0 (P = ns)   Reintervention to LAD at late follow-up (%)   11 vs 2 (P = ns)   Mortality at late follow-up (%)  0 vs 4 (P = ns)   ICC output (ml)  1097 ± 376 vs 675 ± 350 (P = 0.044)     Yang et al. (2017), Med Sci Monit, USA [5] RCT (level II)  63 MIDCAB 63 OPCAB Patients in both groups had multivessel disease  Operation time (min)  65.2 ± 12.6 vs 170.3 ± 12.9 (P = 0.008)   Patients in both groups with LCx and/or RCA pathology underwent stenting postoperatively   Bleeding intraoperatively (ml)  56.4 ± 4.7 vs 258.3 ± 13.9 (P = 0.005)   Hospital LOS (days)  6.8 ± 1.3 vs 12.4 ± 4.2 (P = 0.002)   CCF at 1 year (%)  0 vs 1.6 (P = 0.357)   Mortality at 1 year (%)  3 vs 14 (P = 0.003)   Blood markers 6 weeks postoperatively      Pro-BNP (ng/dl)  198.7 ± 23.1 vs 198.2 ± 16.5 (P = 0.33)         CK-MB (U/l)  0.33 ± 0.11 vs 0.38 ± 0.44 (P = 1.31)     cTnI (U/l)  0.46 ± 0.11 vs 0.87 ± 0.14 (P = 0.33)   CRP (μg/l)  181.7 ± 11.2 vs 194 ± 23.2 (P = 014)     Zhang et al. (2015), Videosurgery Miniinv, Poland [6] Prospective cohort—non randomized (level III)  300 MIDCAB/SHR 355 OPCAB Patients in both groups had multivessel disease  Operation time (min)  152.0 ± 43.5 vs 263.2 ± 52.4 (P < 0.001)   In SHR, MIDCAB usually occurred before PCI Specialized suction-based stabilizer used—developed by authors of this study 4 MIDCAB patients required LIMA lengthening with SV, due to LIMA injury or dissection  Postoperative ventilation (h)  9.27 ± 5.14 vs 24.92 ± 37.87 (P < 0.001)   ICU LOS (h)  24.27 ± 17.25 vs 59.13 ± 60.39 (P < 0.001)   Total transfusion of RBC (units)  0.79 ± 1.58 vs 3.26 ± 5.02 (P < 0.001)   Re-exploration for bleeding (%)  0.67 vs 0.85 (P = 0.794)   Postoperative MI (%)  0.67 vs 0.56 (P = 0.124)   Wound infection (%)  0.33 vs 0.85 (P = 0.403)   30-Day mortality (%)  0.33 vs 0.85 (P = 0.403)     Birla et al. (2013), Ann R Coll Surg Engl, UK [7] Retrospective cohort (level III)  74 MIDCAB/SHR 78 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  8.1%   5 patients in the MIDCAB group underwent hybrid revascularization   Early perioperative period  ICU LOS (h)  38.36 vs 47.87 (P > 0.05)   Hospital LOS (days)  6.1 vs 8.5 (P < 0.05)   Reoperation for bleeding (%)  0 vs 2.7 (P = 0.2)   ICU ventilation (h)  5.04 vs 5.35 (P > 0.05)   Conversion to sternotomy (n)  6 vs NA   Wound infection (%)  5.4 vs 2.7 (P = 0.4)   AF (%)  22.9 vs 15.4 (P = 0.3)   Cerebrovascular event (%)  2.7 vs 0 (P = 0.1)   Mortality (%)  0 vs 0 (P = ns)   Late postoperative period  Mortality (%)  1.4 vs 6.4 (P = 0.1)   Cerebrovascular event (%)  1.4 vs 1.3 (P = 1.0)   Recurrent angina (%)  1.4 vs 5.1 (P = 0.2)   Recurrent MI (%)  1.4 vs 0 (P = 0.3)   ‘Redo’ PCI (%)  1.4 vs 1.3 (P = 1.0)       ‘Redo’ CABG (%)  1.4 vs 0 (P = 0.1)      Halkos et al. (2011), Ann Thorac Surg, USA [8] Retrospective cohort (level III)  147 MIDCAB/HCR 588 OPCAB All patients in both groups had multivessel disease  Ventilation time (h)  17.0 ± 30.8 vs 22.7 ± 89.5 (P = 0.28)   Indications for HCR: proximal or mid-LAD stenosis amenable to MIDCAB and non-LAD lesions amenable to PCI Significantly more female patients in the HCR group Optimal matching used to match MIDCAB with OPCAB patients 4:1  ICU LOS (h)  57.4 ± 145 vs 52.7 ± 87.8 (P = 0.70)   Hospital LOS (days)  6.6 ± 6.7 vs 6.1 ± 4.7 (P = 0.48)   Blood transfusion (%)  52 vs 329 (P < 0.001)   In-hospital mortality (%)  0.7 vs 0.9 (P = 0.84)   In-hospital stroke (%)  0.7 vs 0.7 (P = 1)   In-hospital MI (%)  0.7 vs 0.5 (P = 0.8)   In-hospital MACCE (%)  2 vs 2 (P = 1)   In-hospital renal failure (%)  2.7 vs 2.6 (P = 0.91)   In-hospital AF (%)  20.1 vs 18.5 (P = 0.63)   All repeat revascularization events (%)  12.2 vs 3.7 (P < 0.001)   Target vessel revascularization (%)  8.8 vs 3.1 (P = 0.002)   Progression of native disease (%)  4.8 vs 0.9 (P < 0.001)   Lesion in IMA or IMA-LAD (%)  4.8 vs 1 (P = 0.001)   In-stent restenosis (MIDCAB/HCR only) (%)   3.4   SV occlusion or stenosis (OPCAB only) (%)   2.4   5-year survival (%)  86.8 vs 84.3 (P = 0.61)     Rogers et al. (2013), J Thorac Cardiovasc Surg, USA [9] RCT (level II)  95 thoraCAB 96 OPCAB Patients in both groups had multivessel disease  Median operation time (h)   4.1 vs 3.3  2-centre study with 2 surgeons operating in UK and 1 in Italy No blinding of patients, hospital staff or investigators  Intubation time (min)  256 vs 321 (P = 0.017)   Hospital LOS (days)  5 vs 6 (P = 0.16)   ICU LOS (h)  22.4 vs 23 (P = 0.91)   In-hospital mortality (%)  1 vs 0 (p=ns)   Postoperative arrhythmias (%)  23 vs 35 (P = 0.059)   Perioperative MI (%)  4 vs 1 (P = ns)   Postoperative cardiac arrest (%)  0 vs 0 (P = ns)   Postoperative pulmonary complications (%)   14 vs 10 (P = 0.34)   Postoperative renal complications (%)  0 vs 0 (P = ns)   Postoperative infections (%)  11 vs 11 (P = 0.97)   RBC transfusion (%)  8 vs 13 (P = 0.24)   FVC at DC (l)  1.90 vs 2.15 (P = 0.01)   Fitness for discharge (days)  6 vs 5 (P = 0.53)    Girsbach et al. (2001), Eur J Cardiothorac Surg, Switzerland [10] Retrospective cohort (level III)  31 MIDCAB 39 OPCAB  Operation duration (min)  124 ± 39 vs 134 ± 27 (P = ns)   Small series with single-surgeon experience   Significant complications (%)  23 vs 2.6 (P < 0.01)   Minor early complications (%)  77.4 vs 51.2 (P = ns)   No early complications (%)  29 vs 56.4 (P < 0.05)   Wound issues (requiring ambulatory treatment) (%)   37 vs 13 (P < 0.05)   In-hospital death (%)  0 vs 0 (P = ns)   Less complete revascularization (%)  29 vs 0 (P = 0.01)   Rehospitalization by 3 months (%)  20 vs 2 (P < 0.05)   Thoracic pain at 3 months (%)  30 vs 10.2 (P = ns)   Residual angina at 3 months (%)  10 vs 2.5 (P = ns)   Dyspnoea at 3 months (%)  16.6 vs 5.1 (P = ns)   Pleural effusion at 3 months (%)  10 vs 2.5 (P = ns)   Immediate extubation (%)  71 vs 44 (P < 0.05)     Stanbridge et al. (1999), Eur J Cardiothorac Surg, UK [11] Meta-analysis (level 1)  3304 MIDCAB 3060 OPCAB  5-year survival (%)  86.8 vs 84.3 (P = 0.61)   MIDCAB group from 63 centres OPCAB group from 21 centres Data collated from 1995 to 1998  Total graft occlusion and stenosis rate (%)   10.5 vs 6.4 (P = 0.08)   Early death (%)  0.9 vs 2 (P = ns)   Late death (%)  0.18 vs 0 (P = ns)   Postoperative infarction (%)  2.9 vs 1.45 (P ≤ 0.03)   Occlusion and stenosis prestabilizer introduction (%)—from 4 major series   16 vs NA   Stenosis after stabilizers introduced (%)—from 4 major series   5 vs NA (P < 0.001)     Lapierre et al. (2011), Eur J Cardiothorac Surg, UK [12] Retrospective cohort (level III)  150 MICS 150 OPCAB Patients in both groups had multivessel disease  Conversion to sternotomy (%)  6.7%   More patients in the MICS group with single-vessel revascularization Complete revascularization in all patients in both groups. Five patients in each group received HCR with PCI before or after operation CPB in 28 MICS patients via femoral venous cannulation  Return to operating theatre (%)  3.3 vs 3.3 (P = ns)   Stroke (%)  0 vs 0.7 (P = ns)   Respiratory insufficiency (%)  2.7 vs 4.7 (P = ns)   New renal failure (%)  1.3 vs 2 (P = ns)   New AF (%)  23.3 vs 28 (P = ns)   Median hospital LOS (days)  5 vs 6 (P = 0.02)   Death (%)  0 vs 0 (P = ns)   Deep wound infection (%)  0 vs 4 (P = 0.03)   Median time to return to full activity (days)  12 vs 34 (P < 0.001)        Ruel et al. (2014), J Thorac Cardiovasc Surg [13] Retrospective cohort (level III)  89 MICS Patients had multivessel disease  Conversion to sternotomy (%)  0   100% follow-up at 6 months No comparison to OPCAB group  Incomplete revascularization (%)  0  Superficial and deep chest wound infection           Reoperation (%)  2.2     New AF (%)  17   Median length of stay (days)  4   Pleural effusion (%)  15   Death, aortic complication, MI, CVA (%)   0   Freedom from angina at 6 months (%)  92   LITA vs SV graft patency (%) at 6 months  100 vs 85 (P < 0.001)   AF: atrial fibrillation; BET: best evidence topic; CABG: coronary artery bypass grafting; CCF: congestive cardiac failure; CCS: Canadian Cardiovascular Society; CK-MB: creatine kinase myocardial band; CPB: cardiopulmonary bypass; CRP: C-reactive protein; cTnI: cardiac troponin 1; CVA: cardiovascular accident; DC: discharge; FVC: forced vital capacity; HCR: hybrid coronary revascularization; ICC: intercostal catheter; ICU: intensive care unit; IMA: internal mammary artery; LAD: left anterior descending artery; LCx: left circumflex artery; LIMA: left internal mammary artery; LITA: left internal thoracic artery; LOS: length of stay; LVEF: left ventricular ejection fraction; MACCE: major adverse cardiac and cerebrovascular event; MI: myocardial infarction; MIDCAB: minimally invasive coronary artery bypass; MICS: minimally invasive cardiac surgery; OPCAB: off-pump coronary artery bypass; NA: not applicable; ns: not significant; PCI: percutaneous coronary intervention; pro-BNP: pro-brain natriuretic peptide; RBC: red blood cells; RCA: right coronary artery; SHR: staged hybrid revascularization; SV: saphenous vein. RESULTS There were 3 papers that compared patients with predominantly single-vessel disease. The first of which by Karpazoglu et al. [2] compared outcomes from 54 patients with single-vessel disease treated with MIDCAB or OPCAB, with 27 patients in each group. The authors found no difference in mortality, reoperation, gastrointestinal bleeding, atrial fibrillation (AF), mortality, myocardial infarction (MI), stroke, surgical site infection (SSI) or intensive care unit (ICU) length of stay (LOS). The total hospital LOS was, however, lower (4.5 ± 0.7 vs 5.2 ± 1.4 days; P = 0.03). Detter et al. [3] compared outcomes from 129 MIDCAB and 127 OPCAB patients, all with single-vessel disease. No difference was observed in the rate of conversion to cardiopulmonary bypass, reoperation for bleeding or graft failure, SSI, cerebrovascular accident, MI, mortality, ICU or hospital LOS. Postoperative angiography (7.4 ± 5.8 days) showed no difference in the rates of graft patency, stenoses >50% or reoperation for graft failure. Vicol et al. [4] compared 57 MIDCAB patients with single-vessel disease with 45 OPCAB patients, 37.8% of whom also received a vein graft to a diagonal branch. No difference was observed in ICU LOS, mortality, MI, wound infection, renal failure, neurological complications or reoperation for bleeding. The rate of urgent reintervention was higher in the MIDCAB group (16% vs 0%, P = 0.023). At late follow-up, there was no difference in recurrent angina, MI, reintervention or mortality. Four papers compared patients with multivessel disease who were treated with OPCAB or MIDCAB plus staged hybrid revascularization or hybrid coronary revascularization. Yang et al. [5] randomized 63 patients to MIDCAB/hybrid coronary revascularization surgery and 63 to OPCAB surgery. No difference was observed in hospital LOS or congestive cardiac failure at 1 year. Mortality at 1 year was lower in the MIDCAB group (3% vs 14%, P = 0.003). Zhang et al. [6] compared 300 MIDCAB/staged hybrid revascularization patients with 355 OPCAB patients. No significant difference was observed in re-exploration for bleeding, postoperative MI, SSI or 30-day mortality. The ICU LOS was lower in the MIDCAB group (24.27 ± 17.25 vs 59.13 ± 60.39 h, P< 0.001). Birla et al. [7] compared matched patients, of whom 74 had MIDCAB/staged hybrid revascularization and 78 OPCAB. No difference was observed in the rates of reoperation, SSI, AF, cerebrovascular events or mortality. At late postoperative follow–up, there was no difference in the rates of reoperation, SSI, AF, cerebrovascular events or mortality. At late postoperative follow–up, there was no difference in recurrent MI, angina, cerebrovascular events, ‘redo’ percutaneous coronary intervention or coronary artery bypass grafting. A reduced hospital LOS was observed in the MIDCAB group (6.1 vs 8.2 days, P < 0.05). Halkos et al. [8] compared 147 MIDCAB/hybrid coronary revascularization patients who were matched (optimal matching) 1:4 with 588 OPCAB patients. No difference was observed in early mortality, MI, stroke, renal failure, AF or major adverse cardiac and cerebrovascular events. A significantly increased number of repeat revascularization events (12.2% vs 3.7%, P < 0.001), target vessel revascularization (8.8% vs 3.1%, P = 0.002), progression of native disease (4.8% vs 0.9%, P < 0.001) and internal mammary artery/internal mammary artery–left anterior descending artery lesions (4.8% vs 1%, P < 0.001) in the MIDCAB group was noted; however, there was no difference in 5-year survival. Two papers compared patients with multivessel disease who were treated with MIDCAB/thoraCAB or OPCAB, where in either of the operations, multiple anastomoses were made. In a randomized controlled trial by Rogers et al. [9] of 191 patients, 95 were randomized to thoraCAB and 96 to OPCAB. No difference was observed in hospital LOS, ICU LOS, postoperative arrhythmias, MI, cardiac arrest, pulmonary complications, SSI or mortality. The authors did find differences in lung function at discharge with patients in the MIDCAB group showing a lower forced vital capacity (1.90 l vs 2.15 l, P = 0.01). Gersbach et al. [10] also compared patients with multivessel disease, 31 of whom underwent MIDCAB and 39 OPCAB. More significant early complications (22.5% vs 0%, P < 0.01), wound issues (37% vs 13%, P < 0.05), rehospitalization by 3 months (20% vs 2%, P < 0.05) and less complete revascularization (29% vs 0%, P < 0.01) were observed in the MIDCAB group. Mortality, residual angina, dyspnoea and pleural effusion were comparable at 3 months. One large meta-analysis was reviewed in which there was no differentiation between single- or multivessel disease. Stanbridge et al. [11] compared 3304 MIDCAB patients with 3060 OPCAB patients. The 5-year survival and mortality rate were the same; however, graft stenosis and occlusion were higher in the MIDCAB group (10.5% vs 6.4%, P = 0.08). A reduction in the combined stenosis rate (16–5%, P < 0.0001) after the utilization of myocardial stabilization was noted. However, this had no impact on mortality or MI rate. Two papers reviewed outcomes of minimally invasive coronary surgery (MICS) in patients with multivessel disease. The first of which by Lapierre et al. [12] compared 150 MICS patients with 150 OPCAB patients from a single surgeon and from the same time period. The OPCAB patients were randomly matched for age, gender, left ventricular function and median number of distal anastomoses from a possible 312 OPCAB patients. No difference was observed in the rate of reoperation, stroke, respiratory insufficiency, renal failure, AF, mortality or perioperative percutaneous coronary intervention. A shorter hospital LOS (5 vs 6 days, P = 0.02), lower incidence of deep wound infection (0% vs 4%, P = 0.03) and shorter median time to return to full activity (12 vs 34 days, P < 0.001) in the MICS group was noted. Complete revascularization was achieved in both groups. In this study, 28 patients in the MICS group underwent cardiopulmonary bypass via femoral venous and arterial cannulation. Ruel et al. [13] investigated the outcomes of 89 patients who underwent MICS and had angiographic follow-up at 6 months. No patient in this study had incomplete revascularization, and 6-month follow up showed 100% graft patency in left internal thoracic artery grafts and 85% patency in saphenous vein (SV). There was no difference in postoperative aortic complications, MI, cerebrovascular accident or mortality (0 vs 0, P = ns). CLINICAL BOTTOM LINE MIDCAB and OPCAB are similar in terms of early and mid-term mortality. However, the minimally invasive approach is associated with greater risk of incomplete revascularization, graft occlusion and repeat revascularization than OPCAB via sternotomy. Conflict of interest: none declared. REFERENCES 1 Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact CardioVasc Thorac Surg  2003; 2: 405– 9. Google Scholar CrossRef Search ADS PubMed  2 Karpuzoglu OE, Ozay B, Sener T, Aydin NB, Ketenci B, Aksu T et al.   Comparison of minimally invasive direct coronary artery bypass and off-pump coronary artery bypass in single-vessel disease. Heart Surg Forum  2009; 12: E39– 43. Google Scholar CrossRef Search ADS PubMed  3 Detter C, Reichenspurner H, Boehm DH, Thalhammer M, Schütz A, Reichart B. Single vessel revascularization with beating heart techniques—minithoracotomy or sternotomy? Eur J Cardiothorac Surg  2001; 19: 464– 70. Google Scholar CrossRef Search ADS PubMed  4 Vicol C, Nollert G, Mair H, Samuel V, Lim C, Tiftikidis M et al.   Midterm results of beating heart surgery in 1-vessel disease: minimally invasive direct coronary artery bypass versus off-pump coronary artery bypass with full sternotomy. Heart Surg Forum  2003; 6: 341– 44. Google Scholar PubMed  5 Yang M, Xiao LB, Gao ZH, Zhou JW. Clinical effect and prognosis of off-pump minimally invasive direct coronary artery bypass. Med Sci Monit  2017; 23: 1123– 8. Google Scholar CrossRef Search ADS PubMed  6 Zhang L, Cui Z, Song Z, Yang H, Fu Y, Gong Y et al.   Minimally invasive direct coronary artery bypass for left anterior descending artery revascularisation—analysis of 300 cases. Videosurgery Miniinv  2015; 10: 548– 54. 7 Birla B, Patel P, Aresu G, Asimakopoulos G. Minimally invasive direct coronary artery bypass versus off-pump coronary surgery through sternotomy. Ann R Coll Surg Engl  2013; 95: 481– 5. Google Scholar CrossRef Search ADS PubMed  8 Halkos ME, Vassiliades TA, Douglas JS, Morris DC, Rab T, Liberman HA et al.   Hybrid coronary revascularization versus off-pump coronary artery bypass grafting for the treatment of multivessel coronary artery disease. Ann Thorac Surg  2011; 92: 1695– 702. Google Scholar CrossRef Search ADS PubMed  9 Rogers CA, Pike K, Angelini GD, Reeves BC, Glauber M, Ferrarini M et al.   An open randomised control trial of median sternotomy versus anterolateral left thoracotomy on morbidity and health care resource use in patients having off-pump coronary artery bypass surgery: the sternotomy versus thoracotomy (STET) trial. J Thorac Cardiovasc Surg  2013; 146: 306– 16. Google Scholar CrossRef Search ADS PubMed  10 Gersbach P, Imsand C, von Segesser LK, Delabays A, Vogt P, Stumpe F. Beating heart coronary artery surgery: is sternotomy a suitable alternative to minimally invasive technique? Eur J Cardiothorac Surg  2001; 20: 760– 4. Google Scholar CrossRef Search ADS PubMed  11 Stanbridge RDL, Hadjinikolaou LK. Technical adjuncts in beating heart surgery comparison of MIDCAB to off-pump sternotomy: a meta-analysis. Eur J Cardiothorac Surg  1999; 16: 24– 33. 12 Lapierre H, Chan V, Sohmer B, Mesana TG, Ruel M. Minimally invasive coronary artery bypass graft via small thoracotomy off-pump: a case-matched study. Eur J Cardiothorac Surg  2011; 40: 804– 10. Google Scholar PubMed  13 Ruel M, Shariff MA, Lapierre H, Goyal N, Dennie C, Sadel SM et al.   Results of the minimally invasive coronary artery bypass grafting angiographic patency study. J Thorac Cardiovasc Surg  2014; 147: 203– 9. Google Scholar CrossRef Search ADS PubMed  © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)

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Interactive CardioVascular and Thoracic SurgeryOxford University Press

Published: Mar 22, 2018

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