1-Year Outcomes of Transcatheter Mitral Valve Replacement in Patients With Severe Mitral Annular Calcification

Background: The risk of surgical mitral valve replacement in patients with severe mitral annular calcification (MAC) is high. Several patients worldwide with severe MAC have been treated successfully with transcatheter mitral valve replacement (TMVR) using balloon-expandable aortic transcatheter valves. The TMVR in MAC Global Registry is a multicenter registry that collects data on outcomes of these procedures. Objectives: The goal of this study was to evaluate 1-year outcomes in this registry. Methods: This study was a multicenter retrospective review of clinical outcomes. Results: A total of 116 extreme surgical risk patients with severe MAC underwent TMVR; 106 had a procedure date >1 year before data-lock and were included in the analysis. Their mean age was 73 ± 12 years, and 68% were female. The mean Society of Thoracic Surgeons score was 15.3 ± 11.6%, and 90% were in New York Heart Association functional class III or IV. Thirty-day and 1-year all-cause mortality was 25% and 53.7%, respectively. Most patients who survived 30 days were alive at 1 year (49 of 77 [63.6%]), and the majority (71.8%) were in New York Heart Association functional class I or II. Echocardiography data at 1 year were available in 34 patients. Mean left ventricular ejection fraction was 58.6 ± 11.2%, mean mitral valve area was 1.9 ± 0.5 cm², mean mitral gradient was 5.8 ± 2.2 mm Hg, and 75% had zero or trace mitral regurgitation. Conclusions: TMVR with balloon-expandable aortic valves in extreme surgical risk patients with severe MAC is feasible but associated with high 30-day and 1-year mortality. Most patients who survive the 30-day post-procedural period are alive at 1 year and have sustained improvement of symptoms and transcatheter valve performance. The role of TMVR in patients with MAC requires further evaluation in clinical trials.