Commentary: Attacking mitral annular calcification: Transatrial implantation of balloon-expandable valves

Abstract

Central MessageOpen transatrial balloon-expandable mitral valve replacement for MAC has promising results and allows optimization of valve placement and minimizing left ventricular outflow tract obstruction.See Article page XXX. Open transatrial balloon-expandable mitral valve replacement for MAC has promising results and allows optimization of valve placement and minimizing left ventricular outflow tract obstruction. See Article page XXX. The search for less-invasive remedies for mitral valve dysfunction in severe mitral annular calcification (MAC) continues. In this issue of the Journal, the authors present a fundamentally surgical approach to the problem using balloon-expandable valves via an on-pump, transatrial approach in 126 patients with MAC with mitral stenosis with or without regurgitation.1Brener M.I. Hamandi M. Hong E. Pizano A. Harloff M.T. Garner E.F. et al.Early outcomes following transatrial transcatheter mitral valve replacement in patients with severe mitral annular calcification.J Thorac Cardiovasc Surg. August 20, 2022; ([Epub ahead of print])Abstract Full Text PDF Google Scholar By describing a relatively standardized open transatrial approach to mitral valve replacement (MVR) in MAC, the authors' contribution is a valuable benchmark for the emerging field of transcatheter mitral valve replacement (TMVR). The current submission might be viewed as something of a “gold standard” comparison for future transcatheter approaches to MVR in patients with MAC, since the authors optimized anatomic considerations by using cardiopulmonary bypass and cardioplegic arrest. The authors present 126 patients undergoing open MVR with a balloon-expandable prosthesis from 2014 to 2021. An advantage of this approach is that it allows the surgeon to resect the anterior mitral leaflet, to place at least a few sutures to anchor the valve as anatomic considerations allowed, and to perform a myectomy when the neoleft ventricular outflow tract was less than 200 mm2. Of note, 23.8% of patients underwent myectomy, and in the 8 patients who experienced left ventricular outflow tract obstruction, 7 of 8 did not undergo myectomy. Generally speaking, however, it seems the investigators optimized most of the anatomic concerns with implanting balloon-expandable valves in patients with MAC. These results probably represent the best-possible anatomic result that can be obtained with balloon-expandable valves. The reported procedural outcomes are consistent with the optimized surgical approach: 94.4% technical success with a 4.2% paravalvular leak. In contrast to the present study, other reports amalgamate different approaches to MVR in MAC that are both surgical and catheter-based (ie, transseptal/transapical).2Guerrero M. Wang D.D. Eleid M.F. Pursnani A. Salinger M. Russell H.M. et al.Prospective study of TMVR using balloon-expandable aortic transcatheter valve in MAC: MITRAL trial 1-year outcomes.JACC Interv. 2021; 14: 830-845Crossref PubMed Scopus (16) Google Scholar Whether or not purely transcatheter-based, nonsurgical approaches to TMVR can approximate these results remains to be seen. There are many ongoing clinical trials that are using transapical or transseptal TMVR options. Other options include transseptal TMVR with the Food and Drug Administration–approved SAPIEN 3 valve (Edwards Lifesciences) with or without the need for LAMPOON (electrosurgical laceration of the anterior leaflet) procedure and/or alcohol septal ablation. Nevertheless, to date, no one device recreates all of the advantages of an open transatrial surgical approach. Despite a successful surgery, undoubtedly patients with MAC are one of the most challenging for cardiac surgeons. This illustrated by the current report that the 1-year mortality was 35.4%, with a median follow-up period of only 89 days. By comparison, a recent meta-analysis of different approaches to MVR in MAC found a median 1-year mortality of 15.8% for surgical MVR and 43% for transapical or transseptal transcatheter MVR.3Alexis S.L. Malik A.H. El-Eshmaawi A. George I. Sengupta A. Kodali S.K. et al.Surgical and transcatheter mitral valve replacement in mitral annular calcification: a systematic review.J Am Heart Assoc. 2021; 10: e018514Crossref PubMed Scopus (8) Google Scholar These daunting figures reinforce the importance of the ongoing search for better solutions for MAC mitral valve pathology. We congratulate the authors for an excellent series and adding to the literature on this complex patient anatomy. Early outcomes following transatrial transcatheter mitral valve replacement in patients with severe mitral annular calcificationThe Journal of Thoracic and Cardiovascular SurgeryPreviewImplantation of a transcatheter valve-in-mitral annular calcification (ViMAC) has emerged as an alternative to traditional surgical mitral valve (MV) replacement. Previous studies evaluating ViMAC aggregated transseptal, transapical, and transatrial forms of the procedure, leaving uncertainty about each technique's advantages and disadvantages. Thus, we sought to evaluate clinical outcomes specifically for transatrial ViMAC from the largest multicenter registry to-date. Full-Text PDF