Comparing moderate–severe and severe mitral regurgitation in transcatheter aortic valve replacement on 1-year survival: insights from a Japanese Nationwide Registry

This study aims to compare 1-year outcomes after transcatheter aortic valve replacement (TAVR) between patients with moderate-severe MR and severe MR preoperatively using the Japan Transcatheter Valve Therapy (J-TVT) registry. Patients undergoing TAVR for aortic stenosis between August 2013 and December 2019 with preoperative mitral regurgitation of moderate-severe (group MR3) or severe (group MR4) were included. Patients with a history of valve surgery and dialysis patients were excluded. A total of 2017 patients were included, and 1-year follow-up data were obtained from the registry (follow-up rate 98.5%). Propensity-score matching between MR3 and MR4 groups was performed. All-cause mortality and the composite outcome of death and/or heart failure events were compared. Crude data showed that 1-year survival was significantly higher in the MR 3 (89.8%) than MR 4 (84.7%) groups, and freedom from 1-year mortality and heart failure events was also higher in the MR 3 (87.1%) than MR 4 (80.5%) groups (p = 0.0001). After propensity-score matching, 452 cases (226 cases each in MR 3 group and MR 4 group) were extracted. Cox regression model showed no statistical difference in the 1-year survival rate between MR 3 group (84.5%) and MR 4 group (85.5%) (p = 0.84), nor in freedom from 1-year death and/or heart failure events between MR 3 group (80.2%) and MR 4 group (81.6%) (p = 0.72). The 1-year survival rate and freedom from death and/or heart failure events were found to be similar between patients undergoing TAVR with MR grade 3 and MR grade 4.