TY - JOUR
AU - Tozzi, Piergiorgio
AB - This editorial refers to ‘Impact of recurrent mitral regurgitation after mitral valve repair for functional mitral regurgitation: long-term analysis of competing outcomes’†, by A.H.J. Petrus et al., on page 2206. In this of the European Heart Journal, Petrus and colleagues address the question of whether or not recurrent functional mitral regurgitation (MR) after restrictive mitral annuloplasty has significant impact on the clinical outcome.1 This seems to be a rhetorical question because several observational studies, also mentioned in the study, have already outlined the association between recurrent MR and adverse clinical outcome. However, the effect of recurrent MR on survival is not fully appreciated. The true incidence of recurrent MR after surgical repair of functional MR is distorted by the high mortality rate in this cohort of patients and by historical studies showing that restrictive mitral annuloplasty ensures durable correction of MR.2 Therefore, the research question is anything but rhetorical. This is the first study assessing the incidence of recurrent MR after mitral valve repair in a large (261 patients), homogeneous cohort of patients with ischaemic MR and evaluating the impact of recurrent MR on long-term clinical outcome using competing risk analysis. The authors reviewed their experience on a very selected cohort of patients eligible for restrictive mitral annuloplasty and coronary artery bypass grafts (CABGs) and followed them up for 10 years (median follow-up duration 6.8 years). The main findings are that the incidence of recurrent MR was 9% at 1-year, 20% at 5-year, and 27% at 10-year follow-up; survival was 85% at 1 year, 80% at 2 years, 67% at 5 years, and 46% at 10 years; patients with recurrent MR >2 have a 2.1-fold increased risk of hospital readmission for congestive heart failure and a 3.2-fold increased risk of mortality. The authors also identified findings that independently increase the likelihood of recurrent MR: female gender [hazard ratio (HR) 2.1], history of ST-segment elevation myocardial infarction (STEMI; HR 2.4), QRS >120 ms (HR 2.1), and high left ventricular end-systolic volume index (LVESVI; HR 1.0). The incidence of recurrent MR in the report of Petrus et al. is significantly lower than that reported by the CTSN investigators: 30% at 1 month, 33% at 1 year, and 59% at 2 years.3 However, the CTSN data also take into account the residual MR due to suboptimal MR repair. The clinical outcome associated with recurrent MR after restrictive mitral annuloplasty is so poor that the American Association of Thoracic Surgery consensus guidelines suggests that ‘mitral valve replacement should be the treatment of choice for patients with a high risk for postoperative MR recurrence after simple restrictive annuloplasty and for those undergoing surgery in less-experienced centers where annuloplasty alone is the only repair option offered’.4 The study presented by Petrus et al. led to another consideration: future surgical treatments of functional MR should also prevent or treat recurrent MR. Of course, mitral valve replacement could be the extreme solution to prevent recurrent MR, but a recent meta-analysis reported a rate of death 35% higher in the replacement patients than in the repair subjects.5 Therefore, there is a clear need to improve the durability of the restrictive mitral annuloplasty without increasing the operative mortality of a surgical technique that was first described nearly 40 years ago and has not evolved since then. Even if Petrus et al. identified some predictors for recurrent MR, the mechanisms underlying failure of repairs still need to be completely clarified. Recurrent MR after restrictive annuloplasty with a semi-rigid ring is probably due to increased tethering forces caused by papillary muscle displacement in the enlarged left ventricle as well as more apical placement of the leaflets and leaflet coaptation point. The tethering of mitral valve leaflets involves in particular the posterior leaflet because the restrictive annuloplasty displaces the posterior annulus anteriorly since the anterior leaflet of the mitral annulus is fixed to the aortic root. Therefore, the posterior leaflet remains tethered posteriorly, changing the valve closure in a single anterior leaflet process.6,7 This lack of reverse remodelling of the left ventricle to which residual MR contributes is the major determinant of recurrent MR. Therefore, to maximize the potential for LV recovery, complete correction of coronary ischaemic disease at the time of the mitral surgery and any time after the procedure should be aggressively pursued in order to reduce the risk of recurrent MR. Going beyond the aetiology, recurrent MR is always the result of inadequate coaptation of the posterior and anterior mitral leaflets during systole, which means <2 mm of leaflets overlapping. The problem of recurrent MR has been addressed by some research teams working on adjustable devices. Theoretically, any device allowing leaflet coaptation surface increase any time after the surgical repair should provide correction of the recurrent MR. The leaflet coaptation surface can be increased, reducing the septal–lateral diameter of the mitral valve. The first device developed to reduce the septal–lateral diameter was only adjustable during the surgical procedure soon after weaning off the cardiopulmonary bypass.8 This promising concept was further improved to enable the ring adjustment through a wire using a small percutaneous approach. In this device, the adjustment was achieved thanks to a mitral ring made of memory shape alloy that, when heated, changes its geometry to a pre-formed shape, therefore reducing the septal–lateral diameter (MiCardia EnCorSQ™ Dynamic Annuloplasty Ring System, MiCardia Corp., Irvine, CA, USA).8 More recently, the first-in-man implant of a mitral ring allowing percutaneous reduction of the septal–lateral distance of the mitral valve has been performed at the University Hospital in Vienna by Professor Martin Andreas, and the clinical study for the CE mark certification is ongoing (Kalios Ring, Affluent Medical SA, Paris, France). The device (Figure 1) is an annuloplasty ring that, once implanted, allows the percutaneous and progressive displacement of each of the three anatomical regions of the posterior mitral annulus towards the anterior part. The displacement is permanent and induced by an angioplasty balloon catheter inserted in a line connecting the ring to the subcutaneous tissue.9 The height of the coaptation can also be increased soon after the operation if it does not reach the optimal value of 8 mm.10 According to the literature, this should play a key role in the durability of the mitral repair, either for degenerative or for functional MR. Figure 1 View largeDownload slide Annuloplasty mitral ring with remote access for percutaneous reduction of the septal–lateral distance. (A) The device is implanted using a standard annuloplasty ring technique. The connecting catheter exits the left atrium and reaches the subclavian region (yellow arrow). (B) A gap between mitral leaflets causes recurrent MR. (C) The balloon is inserted in the connecting line and advanced till the P2 segment. The balloon is then inflated, causing permanent deformation of the ring in the P2 area. After the procedure, the balloon is retrieved. Ring deformation reduces the septal–lateral distance, thus improving leaflet coaptation. (D) Ring deformation occurs in the three segments of the posterior leaflet, when needed. Figure 1 View largeDownload slide Annuloplasty mitral ring with remote access for percutaneous reduction of the septal–lateral distance. (A) The device is implanted using a standard annuloplasty ring technique. The connecting catheter exits the left atrium and reaches the subclavian region (yellow arrow). (B) A gap between mitral leaflets causes recurrent MR. (C) The balloon is inserted in the connecting line and advanced till the P2 segment. The balloon is then inflated, causing permanent deformation of the ring in the P2 area. After the procedure, the balloon is retrieved. Ring deformation reduces the septal–lateral distance, thus improving leaflet coaptation. (D) Ring deformation occurs in the three segments of the posterior leaflet, when needed. There is another potential clinical benefit to using an adjustable mitral ring. In functional MR associated with poor left ventricular function (LVEF <30%), the complete correction of the MR with an undersized ring causes the sudden increase in the LV afterload and this is historically associated with high operative and early post-operative mortality due to LV failure.2,3 The possibility of progressively reducing the regurgitation over a few weeks after implant should theoretically induce a smooth increase in the LV afterload, therefore reducing the risk of post-operative heart failure. While it is premature to comment on whether the study by Petrus et al. will be sufficient to promote a change in practice guidelines for the management of functional MR, this study does highlight the limitations of current treatment and emphasizes the need for new surgical therapies that treat recurrent MR avoiding reoperation or with minimal risk for the patient. The future of functional MR treatment is towards first restrictive mitral annuloplasty with an adjustable ring followed by late, iterative percutaneous adjustments of leaflet coaptation. Conflict of interest: P.T. is a shareholder of Affluent Medical SA. The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology. Footnotes † doi:10.1093/eurheartj/ehz306. References 1 Petrus AHJ, Dekkers OM, Tops LF, Timmer E, Klautz RJM, Braun J. Impact of recurrent mitral regurgitation after mitral valve repair for functional mitral regurgitation: long-term analysis of competing outcomes. Eur Heart J 2019;40:2206–2214. 2 Braun J , van de Veire NR , Klautz RJ , Versteegh MI , Holman ER , Westenberg JJ , Boersma E , van der Wall EE , Bax JJ , Dion RA. Restrictive mitral annuloplasty cures mitral regurgitation and heart failure . Ann Thorac Surg 2008 ; 85 : 430 – 436 . Google Scholar Crossref Search ADS PubMed WorldCat 3 Goldstein D , Moskowitz AJ , Gelijns AC , Ailawadi G , Parides MK , Perrault LP , Hung JW , Voisine P , Dagenais F , Gillinov AM , Thourani V , Argenziano M , Gammie JS , Mack M , Demers P , Atluri P , Rose EA , O’Sullivan K , Williams DL , Bagiella E , Michler RE , Weisel RD , Miller MA , Geller NL , Taddei-Peters WC , Smith PK , Moquete E , Overbey JR , Kron IL , O’Gara PT , Acker MA ; CTSN. Two-year outcomes of surgical treatment of severe mitral regurgitation . N Engl J Med 2016 ; 374 : 344 – 353 . Google Scholar Crossref Search ADS PubMed WorldCat 4 Nishimura RA , Otto CM , Bonow RO , Carabello BA , Erwin JP 3rd , Guyton RA , O'Gara PT , Ruiz CE , Skubas NJ , Sorajja P , Sundt TM 3rd , Thomas JD ; American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2014 AHA/ACC guideline for the management of patients with valvular heart disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines . J Am Coll Cardiol 2014 ; 63 : 2438 – 2488 . Google Scholar Crossref Search ADS PubMed WorldCat 5 Salmasi MY , Acharya M , Humayun N , Baskaran D , Hubbard S , Vohra H. Is valve repair preferable to valve replacement in ischaemic mitral regurgitation? A systematic review and meta-analysis . Eur J Cardiothorac Surg 2016 ; 50 : 17 – 28 . Google Scholar Crossref Search ADS PubMed WorldCat 6 Magne J , Sénéchal M , Dumesnil JG , Pibarot P. Ischemic mitral regurgitation: a complex multifaceted disease . Cardiology 2009 ; 112 : 244 – 259 . Google Scholar Crossref Search ADS PubMed WorldCat 7 Nappi F , Avatar Singh SS , Santana O , Mihos CG. Functional mitral regurgitation: an overview for surgical management framework . J Thorac Dis 2018 ; 10 : 4540 – 4555 . Google Scholar Crossref Search ADS PubMed WorldCat 8 Andreas M , Doll N , Livesey S , Castella M , Kocher A , Casselman F , Voth V , Bannister C , Encalada Palacios JF , Pereda D , Laufer G , Czesla M. Safety and feasibility of a novel adjustable mitral annuloplasty ring: a multicentre European experience . Eur J Cardiothorac Surg 2016 ; 49 : 249 – 254 . Google Scholar Crossref Search ADS PubMed WorldCat 9 Tozzi P , Siniscalchi G , Ferrari E , Kirsch M , Havoz D. Percutaneous increase of mitral leaflet coaptation length after mitral valve repair: results from a preclinical study . Interact Cardiovasc Thorac Surg 2018 ; 26 : 681 – 686 . Google Scholar Crossref Search ADS PubMed WorldCat 10 Anyanwu AC , Adams D. Why do mitral valve repairs fail? J Am Soc Echocardiogr 2009 ; 22 : 1265 – 1269 . Google Scholar Crossref Search ADS PubMed WorldCat Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. 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)
TI - The future of functional mitral regurgitation treatment
JF - European Heart Journal
DO - 10.1093/eurheartj/ehz378
DA - 2019-06-05
UR - https://www.deepdyve.com/lp/oxford-university-press/the-future-of-functional-mitral-regurgitation-treatment-hQsmGSX0NU
SP - 2215
EP - 2217
VL - 40
IS - 27
DP - DeepDyve
ER -