Outcomes Following Transcatheter Mitral Valve Replacement Using Dedicated Devices in Patients With Mitral Annular Calcification

Background: Patients with mitral regurgitation (MR) and morphologic presence of relevant mitral annular calcification (MAC) represent a challenging phenotypic subset with limited treatment options. Objectives: The aim of this study was to assess the feasibility of transcatheter mitral valve replacement (TMVR) using dedicated devices for the treatment of MAC patients. Methods: Consecutive patients with symptomatic MR receiving TMVR and with available computed tomography data from the CHOICE-MI (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency) multicenter registry were stratified by the presence of none or mild mitral annular calcification (MACnone/mild) vs moderate or severe mitral annular calcification (MACmod/sev). Results: Among 279 eligible patients (median age = 76.0 years [Q1-Q3: 71.0-81.0 years], EuroSCORE II = 6.2% [Q1-Q3: 3.9%-12.1%]), 222 (79.6%) presented with MACnone/mild and 57 (20.4%) with MACmod/sev. Patients with MACmod/sev had a higher prevalence of extracardiac arteriopathy (P = 0.011) and primary MR (P < 0.001). Although the technical success rate and the extent of MR elimination did not differ, TMVR treatment in MACmod/sev patients was associated with higher rates of postprocedural bleeding complications (P = 0.02) and renal failure (P < 0.001). Functional improvement at the 1- and 2-year follow-up did not differ between groups. At the 2-year follow-up, there were no differences between patients with MACmod/sev and MACnone/mild regarding all-cause mortality (38.5% vs 37.7%; P = 0.76), cardiovascular mortality (21.3% vs 24.9%; P = 0.97), and all-cause mortality or heart failure hospitalization (52.4% vs 46.7%; P = 0.28) CONCLUSIONS: TMVR in patients with MACmod/sev is associated with higher rates of postprocedural complications but similar rates of survival, MR resolution, and functional improvement compared to MACnone/mild. Further studies are necessary to define the role of dedicated TMVR devices in this population. (Choice of Optimal Transcatheter Treatment for Mitral Insufficiency Registry [CHOICE-MI]; NCT04688190).