5-Year Prospective Evaluation of Mitral Valve-in-Valve, Valve-in-Ring, and Valve-in-MAC Outcomes: MITRAL Trial Final Results.

Background: The MITRAL (Mitral Implantation of Transcatheter Valves) trial is the first prospective trial to evaluate the safety and feasibility of balloon-expandable aortic transcatheter heart valves in patients with failed surgical bioprostheses or annuloplasty rings and severe mitral annular calcification treated with mitral valve-in-valve (MViV), valve-in-ring (MViR), or valve-in-mitral annular calcification (ViMAC).
Objectives: The aim of this study was to evaluate 5-year outcomes among these patients.
Methods: A multicenter prospective study was conducted among patients at high surgical risk at 13 U.S. sites. Patients underwent MViV (n = 30), MViR (n = 30), or ViMAC (n = 31) and were followed annually for 5 years. Kansas City Cardiomyopathy Questionnaire scores were obtained at baseline and follow-up visits. Echocardiograms were analyzed at independent core laboratories.
Results: A total of 91 patients underwent transcatheter mitral valve replacement (February 2015 to December 2017). The mean age was 74.3 ± 8.9 years. At 5-year follow-up, the lowest all-cause mortality was observed in the MViV group (21.4%), 94.7% of patients were in NYHA functional class I or II, and the mean mitral gradient was 6.6 ± 2.5 mm Hg. The MViR and ViMAC groups had higher all-cause mortality (65.5% and 67.9%), most survivors were in NYHA functional classes I and II (50% and 55.6%), and mean mitral gradients remained stable (5.8 ± 0.1 and 6.7 ± 2.5 mm Hg). Significant improvements in Kansas City Cardiomyopathy Questionnaire scores were observed when all 3 arms were pooled.
Conclusions: MViV, MViR, and ViMAC procedures were associated with sustained improvement of heart failure symptoms and quality of life among survivors at 5 years. Transcatheter heart valve function remained stable in all 3 groups. Patients treated with MViV had excellent survival at 5 years, whereas survival was lower in the MViR and ViMAC groups, consistent with underlying disease severity. Patients with more residual mitral regurgitation had higher mortality.
Competing Interests: Funding Support and Author Disclosures This study was partially supported by an unrestricted research grant from Edwards Lifesciences. The authors had absolute control over the study design, data collection, analysis and interpretation of data, and writing of this manuscript, and they take full responsibility for the findings. Dr Guerrero has received institutional research grant support from Edwards Lifesciences; and has served as consultant for Abbott Structural Heart and Medtronic. Dr Wang is a consultant for Abbott, Boston Scientific, Edwards Lifesciences, Materialise, and NeoChord. She also receives research grant support from Boston Scientific assigned to her employer Henry Ford Hospital. Dr Tang is a physician proctor and consultant for Medtronic; is a consultant and physician advisory board member for Abbott Structural Heart; and is a consultant for NeoChord. Dr McCabe has received honoraria from Boston Scientific, Cardiovascular Systems, Edwards Lifesciences, and Medtronic. Dr Whisenant has received consulting and speaker fees from Edwards Lifesciences. Dr Hahn has received speaker fees from Abbott Structural, Baylis Medical, Edwards Lifesciences, and Philips Healthcare; has institutional consulting contracts for which she receives no direct compensation with Abbott Structural, Boston Scientific, Edwards Lifesciences, Medtronic, and Novartis; and is chief scientific officer for the echocardiography core laboratory at the Cardiovascular Research Foundation for multiple industry-sponsored trials, for which she receives no direct industry compensation. Dr Rihal has received institutional research grant support from Edwards Lifesciences. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2023 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)