Transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation: insights from the multi-center MITRA-TUNE registry

Background: A-FMR is considered a specific sub-type of secondary MR in patients with atrial fibrillation (AF) and preserved left ventricle ejection fraction (LVEF). Aim of the study was to investigate the acute and mid-term outcomes of transcatheter edge-to-edge mitral valve repair (TMVr) with the MitraClip in atrial functional mitral regurgitation (A-FMR). Methods: The study included patients with A-FMR and concomitant AF who underwent to the MitraClip at 7 Italian Centers. Aim of the study was to assess the safety, efficacy and mid-term cardiovascular outcomes. Results: After reviewing 1153 patients with FMR treated with TMVr from 2009 to 2021, 87 patients (median age 81 years, 61% female) with A-FMR were identified. Technical success was achieved in 97%, 30-day device success in 83% and 30-day procedural success in 80%. All-cause death at 30-day was 5%. Estimated two-year freedom from all-cause death and cardiac death was 60% and 77%, respectively, whereas freedom from all-cause death/heart failure hospitalization was 55%. Residual MR ≤ 2+ was encountered in 89% (n = 47/53) and improvement in NYHA class I/II in 79% (n = 48/61). Post-procedural MR ≥ 2+ (HR 5.400, CI 1.371–21.268) and inter-commissural annular diameter ≥ 35 mm (HR 4.159, CI 1.057–16.363) were independent predictors of all-cause death/heart failure hospitalization during the follow-up. Positive reverse remodeling of left atrium and mitral annular dimensions occurred after TMVr during the follow-up. Conclusions: MitraClip resulted to be a safe and effective option to treat A-FMR in elderly patients.