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Computed tomography characteristics of the aortic valve and the geometry of SAPIEN 3 transcatheter heart valve in patients with bicuspid aortic valve disease

Computed tomography characteristics of the aortic valve and the geometry of SAPIEN 3... Abstract Aims We assessed the geometry of transcatheter heart valve (THV) and valve function associated with SAPIEN 3 implantation in patients with bicuspid aortic valve (BAV) stenosis. Methods and results We included 280 consecutive patients who had a contrast computed tomography (CT) before and after transcatheter aortic valve implantation (TAVI) in our institution. Each THV was assessed by CT at five cross-sectional levels: inflow, annulus, mid, sinus, and outflow. The geometry of THV was assessed for eccentricity (1 – minimum diameter/maximum diameter) and expansion (CT derived external valve area/nominal external valve area). CT measurements and transthoracic echocardiogram data were compared between BAV and tricuspid aortic valve (TAV). Among 280 patients, 41 patients were diagnosed as BAV. Compared to TAV, BAV was associated with lower expansion at mid-level, sinus-level, and outflow-level (mid 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus 95.9 ± 7.2% vs. 101.6 ± 8.5%; P < 0.001, outflow 107.6 ± 6.2% vs. 109.9 ± 6.6%; P = 0.043), and higher eccentricity at all levels [inflow 3.5% (1.9–5.3) vs. 6.0% (3.2–7.5); P < 0.001, annulus 3.1% (1.6–5.2) vs. 5.4% (3.1–7.8); P = 0.002, mid 3.0% (1.4–4.9) vs. 6.0% (3.3–10.4); P < 0.001, sinus 3.0% (1.7–5.1) vs. 7.6% (4.0–11.4); P < 0.001, and outflow 2.5% (1.3–4.3) vs. 4.9% (2.2–7.5); P < 0.001]. There were no differences in frequency of paravalvular leak ≥ moderate and mean post-procedural gradient between BAV and TAV. Conclusion BAV patients have greater THV eccentricity at all levels and lower THV expansion at mid, sinus, and outflow levels than the TAV patients. There were no differences in parameters of valve function between BAV and TAV patients. Despite the observed geometrical differences, TAVI with SAPIEN 3 in BAV patients allows for feasible valve function. transcatheter aortic valve implantation, bicuspid aortic valve, computed tomography, SAPIEN 3 Introduction Bicuspid aortic valve (BAV) is among the most common congenital cardiac abnormalities,1 and this anatomic variation is associated with greater risk of rapid leaflet degeneration and calcification, leading to stenosis of the aortic orifice. Although transcatheter aortic valve implantation (TAVI) has emerged as a promising alternative to surgery in patients with symptomatic aortic stenosis and contraindications to surgery, or in select patients at high risk for surgery, bicuspid anatomy has been considered as an exclusion in randomized trials.2 Early reports have shown that TAVI may be a feasible option for bicuspid patients at high surgical risk.3 These initial studies using first generation devices revealed somewhat disappointing outcomes, particularly with high rate of paravalvular aortic regurgitation (PAR). The Edwards SAPIEN 3 valve (Edwards Lifesciences, Irvine, CA, USA) is a newer generation device that incorporates an outer fabric seal designed to prevent PAR. This external seal has the potential to adapt better to irregularly shaped annuli and valve orifices in patients with bicuspid valves, thus reducing PAR and potentially improving outcomes in this patient group following TAVI. Yoon et al.4 have reported that clinical outcomes for patients with bicuspid valve disease receiving the newer generation valve demonstrate acceptable clinical outcomes. However, there has been no data regarding the geometry of SAPIEN 3 transcatheter heart valve (THV) for bicuspid valve disease using post-procedural contrast-enhanced computed tomography (CT). It is important to evaluate the impact of THV geometry on clinical outcomes for BAV disease post-TAVI, because BAV is regarded as a risk factor for uneven expansion and subsequent dysfunction of the THV. In addition, it may be useful to know the degree of THV deformity BAV patients have, since this information might help determine whether balloon dilatation is required before or after valve implantation, to avoid unnecessary procedural complications as a result. For these reasons, the aim of this study is to assess THV geometry and valve function associated with implantation of the SAPIEN 3 valve in patients with BAV stenosis, as well as clinical outcomes, when compared with tricuspid aortic valve (TAV) disease. Methods Study population and procedure From December 2013 to January 2017, we analysed a total of 280 consecutive participants that received SAPIEN 3 THV (Edwards Lifesciences, Irvine, CA, USA) for aortic valve stenosis, enrolled in the PORTICO IDE randomized trial or RESOLVE registry (Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Thrombosis and Its Treatment with Anticoagulation: NCT02318342) at our institute (Cedars-Sinai Medical Center, Los Angeles, CA, USA). Per study protocol, these patients had post-TAVI CT between December 2014 and February 2017. For the registry, approval by the institutional review board was obtained before study initiation. This study complies with the Declaration of Helsinki, and all patients provided written informed consent. The ethics committee of our institution approved the study protocol. SAPIEN 3 valve was implanted using standard technique.2 Post-dilatation procedure was performed as required (PAR ≥ moderate). Annulus dimensions used for THV sizing were based on CT measurements. The same criteria for THV sizing was used to BAV and TAV. CT image acquisition Contrast-enhanced CT examinations were performed using a second-generation dual-source CT system (SIEMENS SOMATOM Definition Flash; SIEMENS Healthcare, Erlangen, Germany). Patients with insufficient renal function (estimated glomerular filtration rate <30 mL/min) were excluded. A commercially available contrast medium (Omnipaque, GE Healthcare, Little Chalfont, Buckinghamshire, UK) was used with 100 mL in each patient; bolus triggering in the ascending aorta was employed. CT was performed with a collimation of 128 × 0.625 mm, and maximum tube current range was automated for each patient using CARE Dose (SIEMENS Healthcare), with a fixed tube potential of 100–120 kV. Acquisition was done craniocaudally, from the aortic arch to the diaphragm. Images were reconstructed at 0.6 mm slices with 0.3 mm overlap and iterative reconstruction for evaluation at 10% intervals within the 0–90% RR range. CT Digital Imaging and Communications in Medicine (DICOM) data were then transmitted to a dedicated core laboratory. CT analysis Pre-TAVI analysis For annular and atrioventricular dimensions, curved-multiplanar reconstruction analysis was performed using software specifically customized for valve analysis (3mensio Valves Versions 7.2 or 8.1, 3mensio Medical Imaging BV, Bilthoven, Netherlands). A systolic phase was evaluated whenever available. Aortic root measurements were performed as previously described.5 Moreover, aortic valve and left ventricular outflow (LVOT) tract calcium (if present) were also individually quantified using a validated methodology for contrast [850-Hounsfield Unit (HU) threshold].5 The aortic annulus eccentricity was determined as follows: (annulus minimal diameter/annulus maximal diameter). Degree of annulus oversizing was calculated as: [(device area-annulus area)/annulus area] × 100 (Figure 1). Figure 1 View largeDownload slide The methods to calculate native valve oversizing and THV expansion ratio. THV, transcatheter heart valve. Figure 1 View largeDownload slide The methods to calculate native valve oversizing and THV expansion ratio. THV, transcatheter heart valve. BAV morphology analysis BAV morphology was delineated by the TAVI CT Core Lab at our institution. Valve morphology was classified as previously described by Sievers and Schmidtke,6 according to the number of cusps and the presence of raphes, as well as the spatial position and symmetry of raphes and cusps. Type 0 was assigned to morphologies characterized by the presence of two symmetric leaflets/cusps and one commissure without evidence of a raphe. Type 1 was assigned to valve morphologies with one raphe, and Type 2 when two raphes were present. Functional bicuspid valves were assigned as commissural completely fusion between two cusps because of degenerative processes. To facilitate differentiation of functional bicuspid valves from Type 1 bicuspid valves (i.e. distinguish between a secondarily fused commissure and a raphe), further criteria were applied: a raphe does not extend to the same level on the aortic site as the free margins of the cusps that are forming true commissures. Secondly, diagnosis of a functional bicuspid valve requires symmetry of all three cusps, whereas asymmetry is commonly seen in Type 1 bicuspid valves.7 Post-TAVI analysis Each THV was assessed by CT at five cross-sectional levels—inflow, annulus, mid, sinus, and outflow—following the reformatting of the aortic root in the short-axis view (Figure 2A). 8 At each level, the minimum external valve diameter, maximum external valve diameter, and external valve area were measured. THV area was measured by tracing along the external margins of the frame (Figure 2B).9 THV depth at each cusp was measured as the distance from the inflow of the valve to the sinus of Valsalva floor. Annulus level was defined as the plain of mean THV depth above the inflow level (Figure 2C). THV fracture was evaluated with a volume-rendered view. When there were artifacts at each level, those were excluded. These THV assessments were performed by two independent experienced observers in the core laboratory. Inter- and intra-observer variability was also assessed. Figure 2 View largeDownload slide (A) Image at five cross-sectional levels; (1) inflow-level, (2) annulus-level (3) mid-level, (4) sinus-level, and (5) outflow-level. (B) Measurements of THV frame (C) The method to decide mean THV dept. LCC, Left coronary cusp; NCC, Non coronary cusp; RCC, Right coronary cusp; THV, transcatheter heart valve. Figure 2 View largeDownload slide (A) Image at five cross-sectional levels; (1) inflow-level, (2) annulus-level (3) mid-level, (4) sinus-level, and (5) outflow-level. (B) Measurements of THV frame (C) The method to decide mean THV dept. LCC, Left coronary cusp; NCC, Non coronary cusp; RCC, Right coronary cusp; THV, transcatheter heart valve. THV eccentricity and THV expansion THV eccentricity index was calculated as: [1 – (minimum external THV diameter/maximum external THV diameter)] × 100. THV expansion ratio was expressed in relation to labelled prosthesis size as: (observed THV external area/device area labelled size) × 10010 (Figure 1). The nominal external valve areas are 328, 406, 519, and 649 mm2 for the 20, 23, 26, and 29 mm valves, respectively.9 Echocardiographic assessment The severity of pre-TAVI aortic stenosis was assessed by the mean transvalvular gradient and aortic valve area (AVA) calculated with the continuity equation using transthoracic echocardiogram (TTE).11 PAR severity post-TAVI was evaluated using a multi-parametric approach on post-procedural echocardiography and classified following the Valve Academic Research Consortium-2 recommendations (VARC-2) as none-trace, mild, moderate, and severe.12 Study outcome Study outcomes were site-reported using VARC-2 criteria.12 Criteria included acute procedural and 30-day outcomes. Statistical analysis Quantitative variables are expressed as mean ± standard deviation or median [interquartile range (IQR)]. Qualitative variables are presented as numbers and percentages. Comparison of quantitative variables was performed using the unpaired Student t-test or the Mann–Whitney U-test, depending on variable distribution. The χ2 test or Fisher’s exact test were used to compare with qualitative variables. For inter-/intra-observer reproducibility assessment, Bland–Altman analysis was performed. The one-way analysis of variance (ANOVA) or Kruskal–Wallis test was used to determine whether there were any statistically significant differences between the means of three or more groups. If the ANOVA was positive, a post hoc test (Tukey–Kramer) was performed. If the Kruskal–Wallis test was positive, a test for pairwise comparison of subgroups according to Conover was performed. Statistical significance was defined as P-value <0.05. Analyses were performed using PASW statistics 22.0 (SPSS, Chicago, IL, USA) and MedCalc (MedCalc Software, Mariakerke, Belgium). Results Baseline characteristics are described in Table 1. BAV patients were younger than TAV patients [median of 80 years (IQR 70.5–83.0) vs. median of 83 years (IQR 78.0–87.0); P = 0.003]. At baseline, BAV patients had higher mean aortic valve gradients (49.1 ± 14.1 mmHg vs. 44.1 ± 11.4 mmHg; P = 0.012) and smaller AVA than TAV patients (0.58 ± 0.18 mm2 vs. 0.68 ± 0.18 mm2; P = 0.003). Table 1 Patient characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Values are mean ± SD, median (IQR), or n (%). NA, not available; NYHA, New York heart association; SD, standard deviation. Table 1 Patient characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Values are mean ± SD, median (IQR), or n (%). NA, not available; NYHA, New York heart association; SD, standard deviation. Baseline CT characteristics Among 280 patients, 41 patients were diagnosed as BAV, and 239 patients were diagnosed as TAV. Among patients with a confirmed BAV type, 14 (34.1%) patients had functional BAV (see Supplementary data online, Video S1), two (4.9%) patients had Type 0 (see Supplementary data online, Video S2), and 25 (61.0%) patients had Type 1 [left-right (n =21); right-non (n = 4); and left-non (n = 0)] (see Supplementary data online, Video S3) (Figure 3). Baseline CT characteristics are shown in Table 2. Compared to TAV, BAV had larger annulus dimensions [annulus area (520.6 ± 99.2 mm2 vs. 473.9 ± 87.0 mm2; P = 0.002), perimeter (81.8 ± 7.6 mm vs. 78.1 ± 7.2 mm; P = 0.003)], as well as larger sinuses of Valsalva (SOV) [area, median of 930.0 mm2 (IQR 815.2–1060.5) vs. median of 866.6 mm2 (IQR 724.6–990.2); P = 0.005], sinotubular junction (STJ) (diameter 30.7 ± 3.7 mm vs. 28.4 ± 3.1 mm; P < 0.001), LVOT (area, 518.8 ± 124.0 mm2 vs. 467.4 ± 102.3 mm2; P < 0.001), and ascending aorta [diameter, median of 35.0 mm (IQR 32.9–37.4) vs. median of 32.8 mm (IQR 30.6–35.0); P < 0.001]. Furthermore, BAV had greater Leaflet calcium volume when compared with TAV (850-HU threshold) [median of 308.9 mm3 (IQR 166.0–616.9) vs. median of 158.8 mm3 (IQR 67.4–317.7); P < 0.001], and higher left main height (15.0 ± 3.3 mm vs. 13.8 ± 3.3 mm; P = 0.028), and greater aortic root angulation (50.2 ± 8.3° vs. 46.3 ± 8.2°; P = 0.005). Table 2 Baseline CT characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Values are mean ± SD, median (IQR), or n (%). Annulus eccentric index: minimal annulus diameter/maximal annulus diameter. LM, left main; RCA, right coronary artery; SD, standard deviation. Table 2 Baseline CT characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Values are mean ± SD, median (IQR), or n (%). Annulus eccentric index: minimal annulus diameter/maximal annulus diameter. LM, left main; RCA, right coronary artery; SD, standard deviation. Figure 3 View largeDownload slide Representative images in TAV and BAV; (A) TAV, (B) functional BAV, (C) Type 0 BAV, (D) Type 1 BAV (L-R), and (E) Type 1 BAV (R-N). BAV, bicuspid aortic valve; L-R, left-right; R-N, right-non; TAV, transcatheter aortic valve. Figure 3 View largeDownload slide Representative images in TAV and BAV; (A) TAV, (B) functional BAV, (C) Type 0 BAV, (D) Type 1 BAV (L-R), and (E) Type 1 BAV (R-N). BAV, bicuspid aortic valve; L-R, left-right; R-N, right-non; TAV, transcatheter aortic valve. Procedural details TAVI procedural details are presented in Table 3. The rate of pre-dilatation performed was higher in BAV than in TAV (41.4% vs. 20.4%; P = 0.003). This could be because BAV patients had higher leaflet calcification and smaller AVA than TAV patients. Native annulus oversizing was lower in BAV than in TAV (6.0 ± 8.9% vs. 9.8 ± 9.1%; P = 0.014). Table 3 Procedural characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Values are mean ± SD, median (IQR), or n (%). Native annulus oversizing: [(device area − annulus area)/annulus area) × 100. SD, standard deviation. Table 3 Procedural characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Values are mean ± SD, median (IQR), or n (%). Native annulus oversizing: [(device area − annulus area)/annulus area) × 100. SD, standard deviation. Reproducibility of THV measurements at post-TAVI CT From repeated reconstructions for the subset of 20 randomly selected patients, intra-observer variability was −1.5 mm2 for THV area (95% limits of agreement: −16.6 to 13.5 mm2), 0.05 mm for THV maximum diameter (95% limits of agreement: −0.68 to 0.79 mm), −0.19 for THV minimum diameter (95% limits of agreement: −1.09 to −0.70 mm), and −0.11 for THV mean depth (95% limits of agreement: −0.82 to −0.60 mm). Inter-observer variability was −3.4 mm2 for THV area (95% limits of agreement: −41.7 to 35.0 mm2), −0.33 mm for THV maximum diameter (95% limits of agreement: −1.85 to 1.18 mm), 0.4 mm for THV maximum diameter (95% limits of agreement: −1.6 to 2.5 mm), and 0.2 mm for THV mean depth (95% limits of agreement: −2.4 to 2.8 mm). Each measurement showed acceptable reproducibility (Figure 4). Figure 4 View largeDownload slide Bland–Altman analysis for reproducibility of each THV measurement. THV, transcatheter heart valve. Figure 4 View largeDownload slide Bland–Altman analysis for reproducibility of each THV measurement. THV, transcatheter heart valve. THV measurements Measurements of the geometry of SAPIEN 3 THV on CT are shown in Table 4. For THV analysis, three TAV patients were excluded because of severe ulticen on CT (No BAV patients were excluded). There was no case of THV fracture identified by CT. Mean THV depth was not different between two groups. The THV expansion ratio at mid-level, sinus-level, and outflow-level was lower in BAV compared with TAV (mid-level: 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus-level: 95.9 ± 7.2% vs. 101.6 ± 8.5%; P < 0.001; outflow-level; 107.6 ± 6.2% vs. 109.9 ± 6.6%; P = 0.043). The THV eccentricity index at all level was significantly higher in BAV compared with TAV and BAV [inflow-level: 5.8 ± 2.7% vs. 3.8 ± 2.6%; P < 0.001, annulus-level: median of 5.6% (IQR 3.1–8.1) vs. median of 3.1% (IQR 1.6–5.2); P < 0.001, mid-level: median of 6.0% (IQR 4.0–10.1) vs. median of 3.1% (IQR 1.4–5.0); P < 0.001, sinus-level: median of 7.5% (IQR 3.9–11.4) vs. 3.1% (IQR 1.7–5.1), outflow-level: median of 4.5% (IQR 2.0–7.5) vs. median of 2.5% (IQR 1.3–4.3); P < 0.001]. Table 4 THV measurements Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Values are mean ± SD, median (IQR), or n (%). THV, transcatheter heart valve. THV expansion ratio: (THV external area/device area labelled size) × 100; THV eccentricity index: (short THV diameter/long THV diameter) × 100. SD, standard deviation. Table 4 THV measurements Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Values are mean ± SD, median (IQR), or n (%). THV, transcatheter heart valve. THV expansion ratio: (THV external area/device area labelled size) × 100; THV eccentricity index: (short THV diameter/long THV diameter) × 100. SD, standard deviation. Comparison of baseline CT characteristics and geometry of THV between TAV, functional BAV, and congenital BAV Figure 5 shows CT characteristics before and after TAVI between TAV, functional BAV and congenital BAV. Annulus area was larger in congenital BAV than in TAV (531.2 ± 109.3 mm2 vs. 473.9 ± 87.0 mm2; P < 0.05). Leaflet calcification was higher in congenital BAV than in TAV [median of 369.3 mm3 (IQR 185.4–723.8) vs. median of 158.8 mm3 (IQR 67.4–317.7); P < 0.05]. THV expansion ratio was lower in congenital BAV than in TAV (92.7 ± 7.1%vs. 98.2 ± 7.7%; P < 0.05). THV eccentricity index was higher in congenital BAV than in functional BAV and TAV (congenital BAV vs. Functional BAV: 8.3 ± 4.4% vs. 4.5 ± 2.3%; P < 0.05, Congenital BAV vs. TAV: 8.3 ± 4.4% vs. 3.5 ± 7.2%; P < 0.05). Figure 5 View largeDownload slide Comparison of the geometry between TAV, functional BAV and congenital BAV. (A) This graph shows annulus area between three groups. Annulus area was larger in congenital BAV than in TAV. (B) This graph shows leaflet calcification between three groups. Leaflet calcification was higher in congenital BAV than in TAV. (C) This graph shows comparison of expansion ratio between three groups. The expansion ratio was lower in congenital BAV than in TAV. (D) This graph shows comparison of eccentricity index between three groups. The eccentricity index was higher in congenital BAV than functional BAV and TAV. BAV, bicuspid aortic valve; THV, transcatheter heart valve. Figure 5 View largeDownload slide Comparison of the geometry between TAV, functional BAV and congenital BAV. (A) This graph shows annulus area between three groups. Annulus area was larger in congenital BAV than in TAV. (B) This graph shows leaflet calcification between three groups. Leaflet calcification was higher in congenital BAV than in TAV. (C) This graph shows comparison of expansion ratio between three groups. The expansion ratio was lower in congenital BAV than in TAV. (D) This graph shows comparison of eccentricity index between three groups. The eccentricity index was higher in congenital BAV than functional BAV and TAV. BAV, bicuspid aortic valve; THV, transcatheter heart valve. Post-procedural outcomes There were no significant differences in the incidence of peri-procedural complications between the two groups (Table 5). The frequency of need for permanent pacemaker (PPM) implantation was tended to be higher in BAV than TAV (24.3% vs.11.3%; P = 0.054). Table 5 Procedural and clinical outcomes Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Values are mean ± SD or n (%). AV, aortic valve; NA, not available; SD, standard deviation. Table 5 Procedural and clinical outcomes Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Values are mean ± SD or n (%). AV, aortic valve; NA, not available; SD, standard deviation. There were no significant differences between the two groups in the frequency of moderate or severe PAR (2.5% vs.1.3%; P = 0.896) and mean post-procedural gradient (11.9 ± 4.2 mmHg vs. 10.8 ± 4.0 mmHg; P = 0.126). Besides, there was no difference in the rate of mean gradient ≥20 mmHg between two groups (5.0% vs.3.0%; P = 0.386). Discussion The major findings of this study are as follows: (i) SAPIEN 3 THV in BAV was associated with lower expansion ratio and higher eccentricity index at mid-, sinus-, and outflow-level; (ii) However, there were no significant differences in moderate to severe PAR and mean aortic valve gradient at discharge. Enlarged aortic root, dilated ascending aorta, and a higher degree of calcification in BAV compared with TAV BAV patients had a larger LVOT, annulus, SOV, STJ, and ascending aorta than TAV patients, as well as a greater aortic valve calcium volume evaluated with CT. Baseline BAV CT characteristics from our study showed similar results of bicuspid aortopathy compared with what has been previously reported.13,14 THV eccentricity and THV expansion The previous report showed that THV eccentricity was related to the eccentric aortic annulus and annular/valvular calcification.10 In our study, THV eccentricity index in TAV had similar results as our previous study.9 The THV eccentricity index was higher in BAV at all levels compared with TAV. Baseline CT showed no difference in annulus eccentricity between TAV and BAV. Thus, high aortic valve calcification could affect THV eccentricity in BAV patients. Previous reports suggest the THV frame may be unable to expand completely in the presence of pronounced annular eccentricity, heavy calcification, and calcified raphe. In our study, BAV patients had a higher leaflet calcification and lower THV expansion ratio at mid-, sinus-, and outflow-level than TAV patients. THV expansion ratio in BAV patients also could be affected by leaflet calcification even if patients had large aortic size, and were performed pre-dilatation procedure. Watanabe et al.15 reported the expansion ratio of SAPIEN XT in BAV were similar to that in TAV. On the other hand, our study showed different results in SAPIEN 3. This may be related to absence of commissural posts or different cell design between two valve types. The differences of CT characteristics between TAV, functional BAV, and congenital BAV We compared the CT characteristics between TAV, functional BAV, and congenital BAV (Raphe Type 0 and Type 1). Congenital BAV had a larger annulus area, higher leaflet calcification, and lower THV expansion ratio than TAV, and higher THV eccentricity index than both TAV and functional BAV. In addition, functional BAV had no differences in annulus area, leaflet calcification, and THV expansion ratio as compared with TAV and congenital BAV. Baseline CT characteristics and geometry of THV in congenital BAV were different than the TAV, and functional BAV may take an intermediate stance between congenital BAV and TAV in characteristics of baseline CT and SAPIEN3 THV. However, further study of a larger patient population will be required to evaluate clinical outcomes in this different valve morphology. Valve function in BAV patient with SAPIEN 3 valve Prior experience with TAVI in BAV patients with early-generation balloon-expandable and self-expanding valves reported higher rates of PAR compared with TAV patients. Recently, Perman et al.7 reported that there were no clinically significant PAR in BAV patients implanted with SAPEIN 3. In our study, PAR ≥ moderate was just observed in one of the BAV patients. Yang et al.16 reported a Multi Detector CT area oversizing percentage value of ≤4.17% as the optimal cut-off value to discriminate patients with or without mild or greater PAR. Although BAV patients had larger annulus sizes than TAV, there was no statistically significant difference in the frequency of oversizing ≤ 4.17% between TAV and BAV groups (26.3% vs. 34.1%; P = 0.400). Delgado et al.17 stated that a high degree of THV eccentricity might be associated with increased PAR. In our study, BAV patients had higher leaflet calcification and higher eccentricity index at inflow-level, but the expansion ratio at inflow was not different between the two groups, probably due to the similar LVOT calcium volume between the two groups. The valve sealing properties of the external sealing layer of the inflow portion of the SAPIEN 3, and adequate expansion at inflow-level in BAV patients may explain the similar PAR rate in BAV vs. TAV patients. In our study, THV eccentricity index at all levels was higher in BAV than in TAV and THV expansion ratio at mid-, sinus-, and outflow-level was lower in BAV than for TAV. Nevertheless, there were no significant differences in mean gradient between the two groups. Figure 6 showed representative case of THV in BAV patient. BAV case had THV eccentric index at all levels more than 10% and had THV expansion ratio at mid-level lower than 90%. BAV cases showed small non-coronary cusp with severe leaflet calcification and calcified raphe. Small sinus size and calcification with a calcified raphe led to inadequate expansion at mid-level and eccentric THV. Despite THV deformity, TTE showed normal valve function with trivial PAR and mean gradient of 19 mmHg. Figure 6 View largeDownload slide Representative case of the geometry of SAPIEN 3 in BAV patient. This figure shows images of baseline CT, post-TAVI CT, and TTE mean gradient after procedure. SOV, sinuses of Valsalva. Figure 6 View largeDownload slide Representative case of the geometry of SAPIEN 3 in BAV patient. This figure shows images of baseline CT, post-TAVI CT, and TTE mean gradient after procedure. SOV, sinuses of Valsalva. Stroke/transient ischaemic attack (TIA) and PPM after TAVI The rate of Stroke/TIA in BAV was as almost twice as in TAV with no significant difference. Previous filter-based embolic protection device study showed calcified material of captured debris was identified in around 25% of patients.18 High leaflet calcification may be related a cerebrovascular event, although this was unproven in our study. Prior reports about SAPIEN 3 valve in bicuspid patients also documented relatively high rates of PPM.7 In our study, BAV did not have more aggressive oversizing or lower valve implantation than TAV, but the frequency of pre-dilatation in BAV was higher than in TAV (see Supplementary data online, Table S1). Previous studies have reported that pre-dilation was an independent predictor of needing PPM after first generation valve,19 but there is no consensus about pre-dilatation as PPM risk after SAPIEN 3 implantation. Further investigation is required for new PPM risk in BAV disease. Considering this high rate of PPM in BAV, higher THV implantation (more aortic) may be feasible technique for BAV. Study limitations This was a non-randomized, single-centre observational study. It was a retrospective analysis and is limited by the small sample of selected patients who underwent post-procedural CT at our institution, during the study period. All types of BAV were not included in this study. Influence of stent recoil for the duration between THV implant and CT could not be evaluated. Some stents have blooming artifacts on CT so that they might influence our stent-frame measurements. Further, studies to determine the effects of THV deformity are required. Conclusion BAV patients had larger annuli, aortic size, and greater leaflet calcium volume, compared with TAV patients. BAV patients had greater THV eccentricity index at all levels and lower THV expansion ratio at the mid-, sinus-, and outflow-level. Regarding valve function using post-procedural TTE, there were no differences in frequency of any grade of PAR and mean gradient between BAV and TAV. Besides, the rate of high mean gradient (≥20 mmHg) was not different between two groups. TAVI with SAPIEN 3 in BAV allows for feasible procedural results in spite of their THV deformity. Evaluation of long term clinical outcome is required, since an asymmetric expansion might lead to early degeneration of the leaflets. Funding This work was supported by Cedars-Sinai Heart Institute. Conflict of interest: R.R. M. is a consultant for Abbott Vascular, Cordis, and Medtronic; and holds equity in Entourage Medical. R. S. is proctor for Edwards Lifesciences. H. J. is a consultant for Edwards Lifesciences Corporation, St. Jude Medical, and Venus MedTech. All other authors have no conflict of interest. References 1 Siu SC , Silversides CK. Bicuspid aortic valve disease . J Am Coll Cardiol 2010 ; 55 : 2789 – 800 . Google Scholar Crossref Search ADS PubMed 2 Leon MB , Smith CR , Mack M , Miller DC , Moses JW , Svensson LG et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery . N Engl J Med 2010 ; 363 : 1597 – 607 . Google Scholar Crossref Search ADS PubMed 3 Mylotte D , Lefevre T , Sondergaard L , Watanabe Y , Modine T , Dvir D et al. Transcatheter aortic valve replacement in bicuspid aortic valve disease . J Am Coll Cardiol 2014 ; 64 : 2330 – 9 . Google Scholar Crossref Search ADS PubMed 4 Yoon SH , Lefevre T , Ahn JM , Perlman GY , Dvir D , Latib A et al. Transcatheter aortic valve replacement with early- and new-generation devices in bicuspid aortic valve stenosis . J Am Coll Cardiol 2016 ; 68 : 1195 – 205 . Google Scholar Crossref Search ADS PubMed 5 Jilaihawi H , Makkar RR , Kashif M , Okuyama K , Chakravarty T , Shiota T et al. A revised methodology for aortic-valvar complex calcium quantification for transcatheter aortic valve implantation . Eur Heart J Cardiovasc Imaging 2014 ; 15 : 1324 – 32 . Google Scholar Crossref Search ADS PubMed 6 Sievers HH , Schmidtke C. A classification system for the bicuspid aortic valve from 304 surgical specimens . J Thorac Cardiovasc Surg 2007 ; 133 : 1226 – 33 . Google Scholar Crossref Search ADS PubMed 7 Perlman GY , Blanke P , Dvir D , Pache G , Modine T , Barbanti M et al. Bicuspid aortic valve stenosis: favorable early outcomes with a next-generation transcatheter heart valve in a multicenter study . JACC Cardiovasc Interv 2016 ; 9 : 817 – 24 . Google Scholar Crossref Search ADS PubMed 8 Leipsic J , Gurvitch R , Labounty TM , Min JK , Wood D , Johnson M et al. Multidetector computed tomography in transcatheter aortic valve implantation . JACC Cardiovasc Imaging 2011 ; 4 : 416 – 29 . Google Scholar Crossref Search ADS PubMed 9 Kazuno Y , Maeno Y , Kawamori H , Takahashi N , Abramowitz Y , Babak H et al. Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography . Eur Heart J Cardiovasc Imaging 2016 ; 17 : 1054 – 62 . Google Scholar Crossref Search ADS PubMed 10 Willson AB , Webb JG , Gurvitch R , Wood DA , Toggweiler S , Binder R et al. Structural integrity of balloon-expandable stents after transcatheter aortic valve replacement: assessment by multidetector computed tomography . JACC Cardiovasc Interv 2012 ; 5 : 525 – 32 . Google Scholar Crossref Search ADS PubMed 11 Otto CM , Pearlman AS , Comess KA , Reamer RP , Janko CL , Huntsman LL. Determination of the stenotic aortic valve area in adults using Doppler echocardiography . J Am Coll Cardiol 1986 ; 7 : 509 – 17 . Google Scholar Crossref Search ADS PubMed 12 Kappetein AP , Head SJ , Genereux P , Piazza N , van Mieghem NM , Blackstone EH et al. Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document . J Am Coll Cardiol 2012 ; 60 : 1438 – 54 . Google Scholar Crossref Search ADS PubMed 13 Hayashida K , Bouvier E , Lefevre T , Chevalier B , Hovasse T , Romano M et al. Transcatheter aortic valve implantation for patients with severe bicuspid aortic valve stenosis . Circ Cardiovasc Interv 2013 ; 6 : 284 – 91 . Google Scholar Crossref Search ADS PubMed 14 Verma S , Siu SC. Aortic dilatation in patients with bicuspid aortic valve . N Engl J Med 2014 ; 370 : 1920 – 9 . Google Scholar Crossref Search ADS PubMed 15 Watanabe Y , Chevalier B , Hayashida K , Leong T , Bouvier E , Arai T et al. Comparison of multislice computed tomography findings between bicuspid and tricuspid aortic valves before and after transcatheter aortic valve implantation . Catheter Cardiovasc Interv 2015 ; 86 : 323 – 30 . Google Scholar Crossref Search ADS PubMed 16 Yang TH , Webb JG , Blanke P , Dvir D , Hansson NC , Norgaard BL et al. Incidence and severity of paravalvular aortic regurgitation with multidetector computed tomography nominal area oversizing or undersizing after transcatheter heart valve replacement with the Sapien 3: a comparison with the SAPIEN XT . JACC Cardiovasc Interv 2015 ; 8 : 462 – 71 . Google Scholar Crossref Search ADS PubMed 17 Delgado V , Ng AC , van de Veire NR , van der Kley F , Schuijf JD , Tops LF et al. Transcatheter aortic valve implantation: role of multi-detector row computed tomography to evaluate prosthesis positioning and deployment in relation to valve function . Eur Heart J 2010 ; 31 : 1114 – 23 . Google Scholar Crossref Search ADS PubMed 18 Van Mieghem NM , El Faquir N , Rahhab Z , Rodriguez-Olivares R , Wilschut J , Ouhlous M et al. Incidence and predictors of debris embolizing to the brain during transcatheter aortic valve implantation . JACC Cardiovasc Interv 2015 ; 8 : 718 – 24 . Google Scholar Crossref Search ADS PubMed 19 Gensas CS , Caixeta A , Siqueira D , Carvalho LA , Sarmento-Leite R , Mangione JA et al. Predictors of permanent pacemaker requirement after transcatheter aortic valve implantation: insights from a Brazilian registry . Int J Cardiol 2014 ; 175 : 248 – 52 . Google Scholar Crossref Search ADS PubMed Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png European Heart Journal – Cardiovascular Imaging Oxford University Press

Computed tomography characteristics of the aortic valve and the geometry of SAPIEN 3 transcatheter heart valve in patients with bicuspid aortic valve disease

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Oxford University Press
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Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.
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2047-2404
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Abstract

Abstract Aims We assessed the geometry of transcatheter heart valve (THV) and valve function associated with SAPIEN 3 implantation in patients with bicuspid aortic valve (BAV) stenosis. Methods and results We included 280 consecutive patients who had a contrast computed tomography (CT) before and after transcatheter aortic valve implantation (TAVI) in our institution. Each THV was assessed by CT at five cross-sectional levels: inflow, annulus, mid, sinus, and outflow. The geometry of THV was assessed for eccentricity (1 – minimum diameter/maximum diameter) and expansion (CT derived external valve area/nominal external valve area). CT measurements and transthoracic echocardiogram data were compared between BAV and tricuspid aortic valve (TAV). Among 280 patients, 41 patients were diagnosed as BAV. Compared to TAV, BAV was associated with lower expansion at mid-level, sinus-level, and outflow-level (mid 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus 95.9 ± 7.2% vs. 101.6 ± 8.5%; P < 0.001, outflow 107.6 ± 6.2% vs. 109.9 ± 6.6%; P = 0.043), and higher eccentricity at all levels [inflow 3.5% (1.9–5.3) vs. 6.0% (3.2–7.5); P < 0.001, annulus 3.1% (1.6–5.2) vs. 5.4% (3.1–7.8); P = 0.002, mid 3.0% (1.4–4.9) vs. 6.0% (3.3–10.4); P < 0.001, sinus 3.0% (1.7–5.1) vs. 7.6% (4.0–11.4); P < 0.001, and outflow 2.5% (1.3–4.3) vs. 4.9% (2.2–7.5); P < 0.001]. There were no differences in frequency of paravalvular leak ≥ moderate and mean post-procedural gradient between BAV and TAV. Conclusion BAV patients have greater THV eccentricity at all levels and lower THV expansion at mid, sinus, and outflow levels than the TAV patients. There were no differences in parameters of valve function between BAV and TAV patients. Despite the observed geometrical differences, TAVI with SAPIEN 3 in BAV patients allows for feasible valve function. transcatheter aortic valve implantation, bicuspid aortic valve, computed tomography, SAPIEN 3 Introduction Bicuspid aortic valve (BAV) is among the most common congenital cardiac abnormalities,1 and this anatomic variation is associated with greater risk of rapid leaflet degeneration and calcification, leading to stenosis of the aortic orifice. Although transcatheter aortic valve implantation (TAVI) has emerged as a promising alternative to surgery in patients with symptomatic aortic stenosis and contraindications to surgery, or in select patients at high risk for surgery, bicuspid anatomy has been considered as an exclusion in randomized trials.2 Early reports have shown that TAVI may be a feasible option for bicuspid patients at high surgical risk.3 These initial studies using first generation devices revealed somewhat disappointing outcomes, particularly with high rate of paravalvular aortic regurgitation (PAR). The Edwards SAPIEN 3 valve (Edwards Lifesciences, Irvine, CA, USA) is a newer generation device that incorporates an outer fabric seal designed to prevent PAR. This external seal has the potential to adapt better to irregularly shaped annuli and valve orifices in patients with bicuspid valves, thus reducing PAR and potentially improving outcomes in this patient group following TAVI. Yoon et al.4 have reported that clinical outcomes for patients with bicuspid valve disease receiving the newer generation valve demonstrate acceptable clinical outcomes. However, there has been no data regarding the geometry of SAPIEN 3 transcatheter heart valve (THV) for bicuspid valve disease using post-procedural contrast-enhanced computed tomography (CT). It is important to evaluate the impact of THV geometry on clinical outcomes for BAV disease post-TAVI, because BAV is regarded as a risk factor for uneven expansion and subsequent dysfunction of the THV. In addition, it may be useful to know the degree of THV deformity BAV patients have, since this information might help determine whether balloon dilatation is required before or after valve implantation, to avoid unnecessary procedural complications as a result. For these reasons, the aim of this study is to assess THV geometry and valve function associated with implantation of the SAPIEN 3 valve in patients with BAV stenosis, as well as clinical outcomes, when compared with tricuspid aortic valve (TAV) disease. Methods Study population and procedure From December 2013 to January 2017, we analysed a total of 280 consecutive participants that received SAPIEN 3 THV (Edwards Lifesciences, Irvine, CA, USA) for aortic valve stenosis, enrolled in the PORTICO IDE randomized trial or RESOLVE registry (Assessment of Transcatheter and Surgical Aortic Bioprosthetic Valve Thrombosis and Its Treatment with Anticoagulation: NCT02318342) at our institute (Cedars-Sinai Medical Center, Los Angeles, CA, USA). Per study protocol, these patients had post-TAVI CT between December 2014 and February 2017. For the registry, approval by the institutional review board was obtained before study initiation. This study complies with the Declaration of Helsinki, and all patients provided written informed consent. The ethics committee of our institution approved the study protocol. SAPIEN 3 valve was implanted using standard technique.2 Post-dilatation procedure was performed as required (PAR ≥ moderate). Annulus dimensions used for THV sizing were based on CT measurements. The same criteria for THV sizing was used to BAV and TAV. CT image acquisition Contrast-enhanced CT examinations were performed using a second-generation dual-source CT system (SIEMENS SOMATOM Definition Flash; SIEMENS Healthcare, Erlangen, Germany). Patients with insufficient renal function (estimated glomerular filtration rate <30 mL/min) were excluded. A commercially available contrast medium (Omnipaque, GE Healthcare, Little Chalfont, Buckinghamshire, UK) was used with 100 mL in each patient; bolus triggering in the ascending aorta was employed. CT was performed with a collimation of 128 × 0.625 mm, and maximum tube current range was automated for each patient using CARE Dose (SIEMENS Healthcare), with a fixed tube potential of 100–120 kV. Acquisition was done craniocaudally, from the aortic arch to the diaphragm. Images were reconstructed at 0.6 mm slices with 0.3 mm overlap and iterative reconstruction for evaluation at 10% intervals within the 0–90% RR range. CT Digital Imaging and Communications in Medicine (DICOM) data were then transmitted to a dedicated core laboratory. CT analysis Pre-TAVI analysis For annular and atrioventricular dimensions, curved-multiplanar reconstruction analysis was performed using software specifically customized for valve analysis (3mensio Valves Versions 7.2 or 8.1, 3mensio Medical Imaging BV, Bilthoven, Netherlands). A systolic phase was evaluated whenever available. Aortic root measurements were performed as previously described.5 Moreover, aortic valve and left ventricular outflow (LVOT) tract calcium (if present) were also individually quantified using a validated methodology for contrast [850-Hounsfield Unit (HU) threshold].5 The aortic annulus eccentricity was determined as follows: (annulus minimal diameter/annulus maximal diameter). Degree of annulus oversizing was calculated as: [(device area-annulus area)/annulus area] × 100 (Figure 1). Figure 1 View largeDownload slide The methods to calculate native valve oversizing and THV expansion ratio. THV, transcatheter heart valve. Figure 1 View largeDownload slide The methods to calculate native valve oversizing and THV expansion ratio. THV, transcatheter heart valve. BAV morphology analysis BAV morphology was delineated by the TAVI CT Core Lab at our institution. Valve morphology was classified as previously described by Sievers and Schmidtke,6 according to the number of cusps and the presence of raphes, as well as the spatial position and symmetry of raphes and cusps. Type 0 was assigned to morphologies characterized by the presence of two symmetric leaflets/cusps and one commissure without evidence of a raphe. Type 1 was assigned to valve morphologies with one raphe, and Type 2 when two raphes were present. Functional bicuspid valves were assigned as commissural completely fusion between two cusps because of degenerative processes. To facilitate differentiation of functional bicuspid valves from Type 1 bicuspid valves (i.e. distinguish between a secondarily fused commissure and a raphe), further criteria were applied: a raphe does not extend to the same level on the aortic site as the free margins of the cusps that are forming true commissures. Secondly, diagnosis of a functional bicuspid valve requires symmetry of all three cusps, whereas asymmetry is commonly seen in Type 1 bicuspid valves.7 Post-TAVI analysis Each THV was assessed by CT at five cross-sectional levels—inflow, annulus, mid, sinus, and outflow—following the reformatting of the aortic root in the short-axis view (Figure 2A). 8 At each level, the minimum external valve diameter, maximum external valve diameter, and external valve area were measured. THV area was measured by tracing along the external margins of the frame (Figure 2B).9 THV depth at each cusp was measured as the distance from the inflow of the valve to the sinus of Valsalva floor. Annulus level was defined as the plain of mean THV depth above the inflow level (Figure 2C). THV fracture was evaluated with a volume-rendered view. When there were artifacts at each level, those were excluded. These THV assessments were performed by two independent experienced observers in the core laboratory. Inter- and intra-observer variability was also assessed. Figure 2 View largeDownload slide (A) Image at five cross-sectional levels; (1) inflow-level, (2) annulus-level (3) mid-level, (4) sinus-level, and (5) outflow-level. (B) Measurements of THV frame (C) The method to decide mean THV dept. LCC, Left coronary cusp; NCC, Non coronary cusp; RCC, Right coronary cusp; THV, transcatheter heart valve. Figure 2 View largeDownload slide (A) Image at five cross-sectional levels; (1) inflow-level, (2) annulus-level (3) mid-level, (4) sinus-level, and (5) outflow-level. (B) Measurements of THV frame (C) The method to decide mean THV dept. LCC, Left coronary cusp; NCC, Non coronary cusp; RCC, Right coronary cusp; THV, transcatheter heart valve. THV eccentricity and THV expansion THV eccentricity index was calculated as: [1 – (minimum external THV diameter/maximum external THV diameter)] × 100. THV expansion ratio was expressed in relation to labelled prosthesis size as: (observed THV external area/device area labelled size) × 10010 (Figure 1). The nominal external valve areas are 328, 406, 519, and 649 mm2 for the 20, 23, 26, and 29 mm valves, respectively.9 Echocardiographic assessment The severity of pre-TAVI aortic stenosis was assessed by the mean transvalvular gradient and aortic valve area (AVA) calculated with the continuity equation using transthoracic echocardiogram (TTE).11 PAR severity post-TAVI was evaluated using a multi-parametric approach on post-procedural echocardiography and classified following the Valve Academic Research Consortium-2 recommendations (VARC-2) as none-trace, mild, moderate, and severe.12 Study outcome Study outcomes were site-reported using VARC-2 criteria.12 Criteria included acute procedural and 30-day outcomes. Statistical analysis Quantitative variables are expressed as mean ± standard deviation or median [interquartile range (IQR)]. Qualitative variables are presented as numbers and percentages. Comparison of quantitative variables was performed using the unpaired Student t-test or the Mann–Whitney U-test, depending on variable distribution. The χ2 test or Fisher’s exact test were used to compare with qualitative variables. For inter-/intra-observer reproducibility assessment, Bland–Altman analysis was performed. The one-way analysis of variance (ANOVA) or Kruskal–Wallis test was used to determine whether there were any statistically significant differences between the means of three or more groups. If the ANOVA was positive, a post hoc test (Tukey–Kramer) was performed. If the Kruskal–Wallis test was positive, a test for pairwise comparison of subgroups according to Conover was performed. Statistical significance was defined as P-value <0.05. Analyses were performed using PASW statistics 22.0 (SPSS, Chicago, IL, USA) and MedCalc (MedCalc Software, Mariakerke, Belgium). Results Baseline characteristics are described in Table 1. BAV patients were younger than TAV patients [median of 80 years (IQR 70.5–83.0) vs. median of 83 years (IQR 78.0–87.0); P = 0.003]. At baseline, BAV patients had higher mean aortic valve gradients (49.1 ± 14.1 mmHg vs. 44.1 ± 11.4 mmHg; P = 0.012) and smaller AVA than TAV patients (0.58 ± 0.18 mm2 vs. 0.68 ± 0.18 mm2; P = 0.003). Table 1 Patient characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Values are mean ± SD, median (IQR), or n (%). NA, not available; NYHA, New York heart association; SD, standard deviation. Table 1 Patient characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Bicuspid (n = 41) Tricuspid (n = 239) P-value Age (years) 80 (70.5–83.0) 83 (78.0–87.0) 0.003 Weight (kg) 77.2 ± 18.0 79.1 ± 19.4 0.558 Height (cm) 169.2 ± 10.1 167.9 ± 10.1 0.483 Males 28 (68.3) 142 (59.4) 0.282 Hypertension 35 (85.4) 214 (89.5) 0.290 Diabetes mellitus 10 (24.3) 78 (32.6) 0.293 Chronic obstructive pulmonary disease 8 (19.5) 57 (23.8) 0.543 Baseline NYHA functional class III–IV 37 (90.2) 220 (92.1) 0.443 Coronary artery disease 19 (46.3) 141 (59.0) 0.130 Peripheral artery disease 4 (9.8) 50 (20.9) 0.094 Atrial fibrillation 9 (22.0) 62 (25.9) 0.587 Permanent pacemaker 4 (9.8) 32 (13.4) 0.521 Echocardiographic variables  Mean gradient (mmHg) 49.1 ± 14.1 44.1 ± 11.4 0.012  Aortic valve area (mm2) 0.58 ± 0.18 0.68 ± 0.18 0.003  Severe aortic regurgitation 0 (0.0) 0 (0.0) NA  Severe mitral regurgitation 3 (1.3) 0 (0.0) 0.611  Left ventricular ejection fraction (%) 61.0 (45.0–68.0) 64.0 (55.0–68.0) 0.372 Values are mean ± SD, median (IQR), or n (%). NA, not available; NYHA, New York heart association; SD, standard deviation. Baseline CT characteristics Among 280 patients, 41 patients were diagnosed as BAV, and 239 patients were diagnosed as TAV. Among patients with a confirmed BAV type, 14 (34.1%) patients had functional BAV (see Supplementary data online, Video S1), two (4.9%) patients had Type 0 (see Supplementary data online, Video S2), and 25 (61.0%) patients had Type 1 [left-right (n =21); right-non (n = 4); and left-non (n = 0)] (see Supplementary data online, Video S3) (Figure 3). Baseline CT characteristics are shown in Table 2. Compared to TAV, BAV had larger annulus dimensions [annulus area (520.6 ± 99.2 mm2 vs. 473.9 ± 87.0 mm2; P = 0.002), perimeter (81.8 ± 7.6 mm vs. 78.1 ± 7.2 mm; P = 0.003)], as well as larger sinuses of Valsalva (SOV) [area, median of 930.0 mm2 (IQR 815.2–1060.5) vs. median of 866.6 mm2 (IQR 724.6–990.2); P = 0.005], sinotubular junction (STJ) (diameter 30.7 ± 3.7 mm vs. 28.4 ± 3.1 mm; P < 0.001), LVOT (area, 518.8 ± 124.0 mm2 vs. 467.4 ± 102.3 mm2; P < 0.001), and ascending aorta [diameter, median of 35.0 mm (IQR 32.9–37.4) vs. median of 32.8 mm (IQR 30.6–35.0); P < 0.001]. Furthermore, BAV had greater Leaflet calcium volume when compared with TAV (850-HU threshold) [median of 308.9 mm3 (IQR 166.0–616.9) vs. median of 158.8 mm3 (IQR 67.4–317.7); P < 0.001], and higher left main height (15.0 ± 3.3 mm vs. 13.8 ± 3.3 mm; P = 0.028), and greater aortic root angulation (50.2 ± 8.3° vs. 46.3 ± 8.2°; P = 0.005). Table 2 Baseline CT characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Values are mean ± SD, median (IQR), or n (%). Annulus eccentric index: minimal annulus diameter/maximal annulus diameter. LM, left main; RCA, right coronary artery; SD, standard deviation. Table 2 Baseline CT characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Bicuspid (n = 41) Tricuspid (n = 239) P-value Annulus dimensions  Area (mm2) 520.6 ± 99.2 473.9 ± 87.0 0.002  Perimeter (mm) 81.8 ± 7.6 78.1 ± 7.2 0.003  Mean aortic diameter (mm) 25.8 ± 2.4 24.6 ± 2.3 0.003  Eccentric index 0.81 ± 0.07 0.82 ± 0.06 0.398 Sinus of Valsalva area (mm2) 930.0 (815.2–1060.5) 866.6 (724.6–990.2) 0.005 STJ diameter (mm) 30.7 ± 3.7 28.4 ± 3.1 <0.001 Ascending aorta diameter (mm) 35.0 (32.9–37.4) 32.8 (30.6–35.0) <0.001 LVOT area (mm2) 518.8 ± 124.0 467.4 ± 102.3 0.004 Leaflet calcium volume (mm3) (HU-850) 308.9 (166.0–616.9) 158.8 (67.4–317.7) <0.001 LVOT calcium volume (mm3) (HU-850) 0.5 (0.0–6.7) 0.0 (0.0–8.6) 0.468 Aortic valve calcification index (Agaston score) 3710.9 ± 1893.8 3063.3 ± 2010.0 0.056 LM height (mm) 15.0 ± 3.3 13.8 ± 3.3 0.028 RCA height (mm) 18.2 ± 3.6 17.3 ± 3.1 0.122 Aortic root angle (°) 50.2 ± 8.3 46.3 ± 8.2 0.005 Type of bicuspid valve  Type 0 2 (4.9)  Type 1 L-R 21 (51.2)  Type 1 R-N 4 (9.8)  Functional 14 (34.1) Values are mean ± SD, median (IQR), or n (%). Annulus eccentric index: minimal annulus diameter/maximal annulus diameter. LM, left main; RCA, right coronary artery; SD, standard deviation. Figure 3 View largeDownload slide Representative images in TAV and BAV; (A) TAV, (B) functional BAV, (C) Type 0 BAV, (D) Type 1 BAV (L-R), and (E) Type 1 BAV (R-N). BAV, bicuspid aortic valve; L-R, left-right; R-N, right-non; TAV, transcatheter aortic valve. Figure 3 View largeDownload slide Representative images in TAV and BAV; (A) TAV, (B) functional BAV, (C) Type 0 BAV, (D) Type 1 BAV (L-R), and (E) Type 1 BAV (R-N). BAV, bicuspid aortic valve; L-R, left-right; R-N, right-non; TAV, transcatheter aortic valve. Procedural details TAVI procedural details are presented in Table 3. The rate of pre-dilatation performed was higher in BAV than in TAV (41.4% vs. 20.4%; P = 0.003). This could be because BAV patients had higher leaflet calcification and smaller AVA than TAV patients. Native annulus oversizing was lower in BAV than in TAV (6.0 ± 8.9% vs. 9.8 ± 9.1%; P = 0.014). Table 3 Procedural characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Values are mean ± SD, median (IQR), or n (%). Native annulus oversizing: [(device area − annulus area)/annulus area) × 100. SD, standard deviation. Table 3 Procedural characteristics Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedure access  Transfemoral 40 (97.6) 236 (99.6) 0.471 Prosthesis size  20 mm 0 (0.0) 5 (2.1) 0.767  23 mm 8 (19.5) 63 (26.4) 0.461  26 mm 17 (41.5) 112 (47.7) 0.638  29 mm 16 (39.0) 59 (25.1) 0.085 Balloon pre-dilatation performed 17 (41.4) 48 (20.4) 0.003 Balloon post-dilatation performed 1 (2.4) 12 (5.1) 0.407 Native annulus oversizing (%) 6.0 ± 8.9 9.8 ± 9.1 0.014 Total contrast (mL) 70.0 (50–102.5) 60.0 (43.5–80.0) 0.292 Total fluro time (min) 9.5 (8.2–17.2) 10.5 (7.5–16.0) 0.986 Values are mean ± SD, median (IQR), or n (%). Native annulus oversizing: [(device area − annulus area)/annulus area) × 100. SD, standard deviation. Reproducibility of THV measurements at post-TAVI CT From repeated reconstructions for the subset of 20 randomly selected patients, intra-observer variability was −1.5 mm2 for THV area (95% limits of agreement: −16.6 to 13.5 mm2), 0.05 mm for THV maximum diameter (95% limits of agreement: −0.68 to 0.79 mm), −0.19 for THV minimum diameter (95% limits of agreement: −1.09 to −0.70 mm), and −0.11 for THV mean depth (95% limits of agreement: −0.82 to −0.60 mm). Inter-observer variability was −3.4 mm2 for THV area (95% limits of agreement: −41.7 to 35.0 mm2), −0.33 mm for THV maximum diameter (95% limits of agreement: −1.85 to 1.18 mm), 0.4 mm for THV maximum diameter (95% limits of agreement: −1.6 to 2.5 mm), and 0.2 mm for THV mean depth (95% limits of agreement: −2.4 to 2.8 mm). Each measurement showed acceptable reproducibility (Figure 4). Figure 4 View largeDownload slide Bland–Altman analysis for reproducibility of each THV measurement. THV, transcatheter heart valve. Figure 4 View largeDownload slide Bland–Altman analysis for reproducibility of each THV measurement. THV, transcatheter heart valve. THV measurements Measurements of the geometry of SAPIEN 3 THV on CT are shown in Table 4. For THV analysis, three TAV patients were excluded because of severe ulticen on CT (No BAV patients were excluded). There was no case of THV fracture identified by CT. Mean THV depth was not different between two groups. The THV expansion ratio at mid-level, sinus-level, and outflow-level was lower in BAV compared with TAV (mid-level: 94.1 ± 6.8% vs. 98.1 ± 7.8%; P = 0.002, sinus-level: 95.9 ± 7.2% vs. 101.6 ± 8.5%; P < 0.001; outflow-level; 107.6 ± 6.2% vs. 109.9 ± 6.6%; P = 0.043). The THV eccentricity index at all level was significantly higher in BAV compared with TAV and BAV [inflow-level: 5.8 ± 2.7% vs. 3.8 ± 2.6%; P < 0.001, annulus-level: median of 5.6% (IQR 3.1–8.1) vs. median of 3.1% (IQR 1.6–5.2); P < 0.001, mid-level: median of 6.0% (IQR 4.0–10.1) vs. median of 3.1% (IQR 1.4–5.0); P < 0.001, sinus-level: median of 7.5% (IQR 3.9–11.4) vs. 3.1% (IQR 1.7–5.1), outflow-level: median of 4.5% (IQR 2.0–7.5) vs. median of 2.5% (IQR 1.3–4.3); P < 0.001]. Table 4 THV measurements Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Values are mean ± SD, median (IQR), or n (%). THV, transcatheter heart valve. THV expansion ratio: (THV external area/device area labelled size) × 100; THV eccentricity index: (short THV diameter/long THV diameter) × 100. SD, standard deviation. Table 4 THV measurements Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Bicuspid (n = 41) Tricuspid (n = 236) P-value THV expansion ratio (%)  Inflow 105.0 ± 6.4 106.0 ± 6.6 0.345  Annulus 98.4 ± 5.4 100.6 ± 7.1 0.074  Mid 93.9 ± 6.7 98.3 ± 7.7 <0.001  Sinus 95.9 ± 7.1 101.7 ± 8.4 <0.001  Outflow 107.6 ± 6.2 109.9 ± 6.6 0.043 THV eccentricity index (%)  Inflow 5.8 ± 2.7 3.8 ± 2.6 <0.001  Annulus 5.6 (3.1–8.1) 3.1 (1.6–5.2) <0.001  Mid 6.0 (4.0–10.1) 3.1 (1.4–5.0) <0.001  Sinus 7.5 (3.9–11.4) 3.1 (1.7–5.1) <0.001  Outflow 4.5 (2.0–7.5) 2.5 (1.3–4.3) <0.001 Mean THV depth (mm) 4.9 (2.4–6.1) 4.1 (3.0–5.5) 0.658 Values are mean ± SD, median (IQR), or n (%). THV, transcatheter heart valve. THV expansion ratio: (THV external area/device area labelled size) × 100; THV eccentricity index: (short THV diameter/long THV diameter) × 100. SD, standard deviation. Comparison of baseline CT characteristics and geometry of THV between TAV, functional BAV, and congenital BAV Figure 5 shows CT characteristics before and after TAVI between TAV, functional BAV and congenital BAV. Annulus area was larger in congenital BAV than in TAV (531.2 ± 109.3 mm2 vs. 473.9 ± 87.0 mm2; P < 0.05). Leaflet calcification was higher in congenital BAV than in TAV [median of 369.3 mm3 (IQR 185.4–723.8) vs. median of 158.8 mm3 (IQR 67.4–317.7); P < 0.05]. THV expansion ratio was lower in congenital BAV than in TAV (92.7 ± 7.1%vs. 98.2 ± 7.7%; P < 0.05). THV eccentricity index was higher in congenital BAV than in functional BAV and TAV (congenital BAV vs. Functional BAV: 8.3 ± 4.4% vs. 4.5 ± 2.3%; P < 0.05, Congenital BAV vs. TAV: 8.3 ± 4.4% vs. 3.5 ± 7.2%; P < 0.05). Figure 5 View largeDownload slide Comparison of the geometry between TAV, functional BAV and congenital BAV. (A) This graph shows annulus area between three groups. Annulus area was larger in congenital BAV than in TAV. (B) This graph shows leaflet calcification between three groups. Leaflet calcification was higher in congenital BAV than in TAV. (C) This graph shows comparison of expansion ratio between three groups. The expansion ratio was lower in congenital BAV than in TAV. (D) This graph shows comparison of eccentricity index between three groups. The eccentricity index was higher in congenital BAV than functional BAV and TAV. BAV, bicuspid aortic valve; THV, transcatheter heart valve. Figure 5 View largeDownload slide Comparison of the geometry between TAV, functional BAV and congenital BAV. (A) This graph shows annulus area between three groups. Annulus area was larger in congenital BAV than in TAV. (B) This graph shows leaflet calcification between three groups. Leaflet calcification was higher in congenital BAV than in TAV. (C) This graph shows comparison of expansion ratio between three groups. The expansion ratio was lower in congenital BAV than in TAV. (D) This graph shows comparison of eccentricity index between three groups. The eccentricity index was higher in congenital BAV than functional BAV and TAV. BAV, bicuspid aortic valve; THV, transcatheter heart valve. Post-procedural outcomes There were no significant differences in the incidence of peri-procedural complications between the two groups (Table 5). The frequency of need for permanent pacemaker (PPM) implantation was tended to be higher in BAV than TAV (24.3% vs.11.3%; P = 0.054). Table 5 Procedural and clinical outcomes Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Values are mean ± SD or n (%). AV, aortic valve; NA, not available; SD, standard deviation. Table 5 Procedural and clinical outcomes Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Bicuspid (n = 41) Tricuspid (n = 239) P-value Procedural outcomes  Procedural death 0 (0.0) 0 (0.0) NA  Prosthesis embolization 0 (0.0) 0 (0.0) NA  Tamponade 0 (0.0) 0 (0.0) NA Device success 40 (97.6) 232 (97.0) 0.739 Post-procedure TTE  Paravalvular aortic regurgitation  None/trace 31 (77.5) 193 (82.1) 0.915  Mild 8 (20.0) 39 (16.6) 0.820  Moderate/severe 1 (2.5) 3 (1.3) 0.896  Mean AV gradient (mmHg) 11.9 ± 4.2 10.8 ± 4.0 0.126  Mean gradient ≥20 mmHg 2 (5.0) 7 (3.0) 0.386  Left ventricular ejection fraction (%) 60.5 ± 14.5 64.1 ± 13.0 0.106 30-day outcome  Death 0 (0.0) 1 (0.4) 0.854  Stroke or TIA 3 (7.3) 9 (3.8) 0.249  Major vascular complication 1 (2.4) 1 (0.4) 0.854  Bleeding (life-threatening or major bleeding) 1 (2.4) 2 (0.8) 0.932  Acute kidney injury ≥ Stage 3 0 (0.0) 2 (0.8) 0.728  New pacemaker 9 (24.3) 23 (11.1) 0.054  Early safety 4 (9.8) 10 (4.2) 0.261 Values are mean ± SD or n (%). AV, aortic valve; NA, not available; SD, standard deviation. There were no significant differences between the two groups in the frequency of moderate or severe PAR (2.5% vs.1.3%; P = 0.896) and mean post-procedural gradient (11.9 ± 4.2 mmHg vs. 10.8 ± 4.0 mmHg; P = 0.126). Besides, there was no difference in the rate of mean gradient ≥20 mmHg between two groups (5.0% vs.3.0%; P = 0.386). Discussion The major findings of this study are as follows: (i) SAPIEN 3 THV in BAV was associated with lower expansion ratio and higher eccentricity index at mid-, sinus-, and outflow-level; (ii) However, there were no significant differences in moderate to severe PAR and mean aortic valve gradient at discharge. Enlarged aortic root, dilated ascending aorta, and a higher degree of calcification in BAV compared with TAV BAV patients had a larger LVOT, annulus, SOV, STJ, and ascending aorta than TAV patients, as well as a greater aortic valve calcium volume evaluated with CT. Baseline BAV CT characteristics from our study showed similar results of bicuspid aortopathy compared with what has been previously reported.13,14 THV eccentricity and THV expansion The previous report showed that THV eccentricity was related to the eccentric aortic annulus and annular/valvular calcification.10 In our study, THV eccentricity index in TAV had similar results as our previous study.9 The THV eccentricity index was higher in BAV at all levels compared with TAV. Baseline CT showed no difference in annulus eccentricity between TAV and BAV. Thus, high aortic valve calcification could affect THV eccentricity in BAV patients. Previous reports suggest the THV frame may be unable to expand completely in the presence of pronounced annular eccentricity, heavy calcification, and calcified raphe. In our study, BAV patients had a higher leaflet calcification and lower THV expansion ratio at mid-, sinus-, and outflow-level than TAV patients. THV expansion ratio in BAV patients also could be affected by leaflet calcification even if patients had large aortic size, and were performed pre-dilatation procedure. Watanabe et al.15 reported the expansion ratio of SAPIEN XT in BAV were similar to that in TAV. On the other hand, our study showed different results in SAPIEN 3. This may be related to absence of commissural posts or different cell design between two valve types. The differences of CT characteristics between TAV, functional BAV, and congenital BAV We compared the CT characteristics between TAV, functional BAV, and congenital BAV (Raphe Type 0 and Type 1). Congenital BAV had a larger annulus area, higher leaflet calcification, and lower THV expansion ratio than TAV, and higher THV eccentricity index than both TAV and functional BAV. In addition, functional BAV had no differences in annulus area, leaflet calcification, and THV expansion ratio as compared with TAV and congenital BAV. Baseline CT characteristics and geometry of THV in congenital BAV were different than the TAV, and functional BAV may take an intermediate stance between congenital BAV and TAV in characteristics of baseline CT and SAPIEN3 THV. However, further study of a larger patient population will be required to evaluate clinical outcomes in this different valve morphology. Valve function in BAV patient with SAPIEN 3 valve Prior experience with TAVI in BAV patients with early-generation balloon-expandable and self-expanding valves reported higher rates of PAR compared with TAV patients. Recently, Perman et al.7 reported that there were no clinically significant PAR in BAV patients implanted with SAPEIN 3. In our study, PAR ≥ moderate was just observed in one of the BAV patients. Yang et al.16 reported a Multi Detector CT area oversizing percentage value of ≤4.17% as the optimal cut-off value to discriminate patients with or without mild or greater PAR. Although BAV patients had larger annulus sizes than TAV, there was no statistically significant difference in the frequency of oversizing ≤ 4.17% between TAV and BAV groups (26.3% vs. 34.1%; P = 0.400). Delgado et al.17 stated that a high degree of THV eccentricity might be associated with increased PAR. In our study, BAV patients had higher leaflet calcification and higher eccentricity index at inflow-level, but the expansion ratio at inflow was not different between the two groups, probably due to the similar LVOT calcium volume between the two groups. The valve sealing properties of the external sealing layer of the inflow portion of the SAPIEN 3, and adequate expansion at inflow-level in BAV patients may explain the similar PAR rate in BAV vs. TAV patients. In our study, THV eccentricity index at all levels was higher in BAV than in TAV and THV expansion ratio at mid-, sinus-, and outflow-level was lower in BAV than for TAV. Nevertheless, there were no significant differences in mean gradient between the two groups. Figure 6 showed representative case of THV in BAV patient. BAV case had THV eccentric index at all levels more than 10% and had THV expansion ratio at mid-level lower than 90%. BAV cases showed small non-coronary cusp with severe leaflet calcification and calcified raphe. Small sinus size and calcification with a calcified raphe led to inadequate expansion at mid-level and eccentric THV. Despite THV deformity, TTE showed normal valve function with trivial PAR and mean gradient of 19 mmHg. Figure 6 View largeDownload slide Representative case of the geometry of SAPIEN 3 in BAV patient. This figure shows images of baseline CT, post-TAVI CT, and TTE mean gradient after procedure. SOV, sinuses of Valsalva. Figure 6 View largeDownload slide Representative case of the geometry of SAPIEN 3 in BAV patient. This figure shows images of baseline CT, post-TAVI CT, and TTE mean gradient after procedure. SOV, sinuses of Valsalva. Stroke/transient ischaemic attack (TIA) and PPM after TAVI The rate of Stroke/TIA in BAV was as almost twice as in TAV with no significant difference. Previous filter-based embolic protection device study showed calcified material of captured debris was identified in around 25% of patients.18 High leaflet calcification may be related a cerebrovascular event, although this was unproven in our study. Prior reports about SAPIEN 3 valve in bicuspid patients also documented relatively high rates of PPM.7 In our study, BAV did not have more aggressive oversizing or lower valve implantation than TAV, but the frequency of pre-dilatation in BAV was higher than in TAV (see Supplementary data online, Table S1). Previous studies have reported that pre-dilation was an independent predictor of needing PPM after first generation valve,19 but there is no consensus about pre-dilatation as PPM risk after SAPIEN 3 implantation. Further investigation is required for new PPM risk in BAV disease. Considering this high rate of PPM in BAV, higher THV implantation (more aortic) may be feasible technique for BAV. Study limitations This was a non-randomized, single-centre observational study. It was a retrospective analysis and is limited by the small sample of selected patients who underwent post-procedural CT at our institution, during the study period. All types of BAV were not included in this study. Influence of stent recoil for the duration between THV implant and CT could not be evaluated. Some stents have blooming artifacts on CT so that they might influence our stent-frame measurements. Further, studies to determine the effects of THV deformity are required. Conclusion BAV patients had larger annuli, aortic size, and greater leaflet calcium volume, compared with TAV patients. BAV patients had greater THV eccentricity index at all levels and lower THV expansion ratio at the mid-, sinus-, and outflow-level. Regarding valve function using post-procedural TTE, there were no differences in frequency of any grade of PAR and mean gradient between BAV and TAV. Besides, the rate of high mean gradient (≥20 mmHg) was not different between two groups. TAVI with SAPIEN 3 in BAV allows for feasible procedural results in spite of their THV deformity. Evaluation of long term clinical outcome is required, since an asymmetric expansion might lead to early degeneration of the leaflets. Funding This work was supported by Cedars-Sinai Heart Institute. Conflict of interest: R.R. M. is a consultant for Abbott Vascular, Cordis, and Medtronic; and holds equity in Entourage Medical. R. S. is proctor for Edwards Lifesciences. H. J. is a consultant for Edwards Lifesciences Corporation, St. Jude Medical, and Venus MedTech. All other authors have no conflict of interest. References 1 Siu SC , Silversides CK. Bicuspid aortic valve disease . J Am Coll Cardiol 2010 ; 55 : 2789 – 800 . 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Comparison of multislice computed tomography findings between bicuspid and tricuspid aortic valves before and after transcatheter aortic valve implantation . Catheter Cardiovasc Interv 2015 ; 86 : 323 – 30 . Google Scholar Crossref Search ADS PubMed 16 Yang TH , Webb JG , Blanke P , Dvir D , Hansson NC , Norgaard BL et al. Incidence and severity of paravalvular aortic regurgitation with multidetector computed tomography nominal area oversizing or undersizing after transcatheter heart valve replacement with the Sapien 3: a comparison with the SAPIEN XT . JACC Cardiovasc Interv 2015 ; 8 : 462 – 71 . Google Scholar Crossref Search ADS PubMed 17 Delgado V , Ng AC , van de Veire NR , van der Kley F , Schuijf JD , Tops LF et al. Transcatheter aortic valve implantation: role of multi-detector row computed tomography to evaluate prosthesis positioning and deployment in relation to valve function . Eur Heart J 2010 ; 31 : 1114 – 23 . Google Scholar Crossref Search ADS PubMed 18 Van Mieghem NM , El Faquir N , Rahhab Z , Rodriguez-Olivares R , Wilschut J , Ouhlous M et al. Incidence and predictors of debris embolizing to the brain during transcatheter aortic valve implantation . JACC Cardiovasc Interv 2015 ; 8 : 718 – 24 . Google Scholar Crossref Search ADS PubMed 19 Gensas CS , Caixeta A , Siqueira D , Carvalho LA , Sarmento-Leite R , Mangione JA et al. Predictors of permanent pacemaker requirement after transcatheter aortic valve implantation: insights from a Brazilian registry . Int J Cardiol 2014 ; 175 : 248 – 52 . Google Scholar Crossref Search ADS PubMed Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Journal

European Heart Journal – Cardiovascular Imaging – Oxford University Press

Published: Dec 1, 2018

References

  • Bicuspid aortic valve disease
  • Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery
  • Transcatheter aortic valve replacement in bicuspid aortic valve disease
  • Transcatheter aortic valve replacement with early- and new-generation devices in bicuspid aortic valve stenosis
  • A revised methodology for aortic-valvar complex calcium quantification for transcatheter aortic valve implantation
  • A classification system for the bicuspid aortic valve from 304 surgical specimens
  • Bicuspid aortic valve stenosis: favorable early outcomes with a next-generation transcatheter heart valve in a multicenter study
  • Multidetector computed tomography in transcatheter aortic valve implantation
  • Comparison of SAPIEN 3 and SAPIEN XT transcatheter heart valve stent-frame expansion: evaluation using multi-slice computed tomography
  • Structural integrity of balloon-expandable stents after transcatheter aortic valve replacement: assessment by multidetector computed tomography
  • Determination of the stenotic aortic valve area in adults using Doppler echocardiography
  • Updated standardized endpoint definitions for transcatheter aortic valve implantation: the Valve Academic Research Consortium-2 consensus document
  • Transcatheter aortic valve implantation for patients with severe bicuspid aortic valve stenosis
  • Aortic dilatation in patients with bicuspid aortic valve
  • Comparison of multislice computed tomography findings between bicuspid and tricuspid aortic valves before and after transcatheter aortic valve implantation
  • Incidence and severity of paravalvular aortic regurgitation with multidetector computed tomography nominal area oversizing or undersizing after transcatheter heart valve replacement with the Sapien 3: a comparison with the SAPIEN XT
  • Transcatheter aortic valve implantation: role of multi-detector row computed tomography to evaluate prosthesis positioning and deployment in relation to valve function
  • Incidence and predictors of debris embolizing to the brain during transcatheter aortic valve implantation
  • Predictors of permanent pacemaker requirement after transcatheter aortic valve implantation: insights from a Brazilian registry