Residual Mitral Regurgitation as a Long-Term Predictor of Mortality After Mitral TEER

BACKGROUND: The MITRA-PRO registry revealed residual mitral regurgitation (MR) as an important predictor of 1-year and 3-year mortality following mitral transcatheter edge-to-edge repair (M-TEER). OBJECTIVES: The 5-year follow-up of the MITRA-PRO registry (N = 1,491) aimed to assess the impact of residual MR on 5-year mortality. Furthermore, time-dependent predictors of mortality after M-TEER should be assessed. METHODS: Patients with a MitraScore of ≤3 were classified as patients with mild residual MR after M-TEER, while a MitraScore of ≥4 was defined as relevant residual MR. Adjusted HRs were calculated for multivariate analysis of time-dependent predictors. RESULTS: Five-year mortality was significantly lower in patients with mild or less residual MR compared with patients with more than mild residual MR (MitraScore ≤3 group: 55.1% vs MitraScore ≥4 group: 67.7%). The relationship between intraprocedural MitraScore after M-TEER and mortality was almost linear. In patients with degenerative MR, 5-year mortality was 53.1% in the MitraScore ≤3 group and 73.2% in the MitraScore ≥4 group. Regarding functional MR, the corresponding 5-year mortality rates were 55.0% and 64.6%. Mortality predictors after M-TEER were time dependent: Early risk was driven by advanced disease and procedural factors, whereas residual MR became prognostic after 30 days and remained associated with excess long-term mortality. CONCLUSIONS: Residual MR assessed by intraprocedural MitraScore after M-TEER independently predicts 5-year mortality. This finding underscores the importance of achieving optimal MR reduction during M-TEER and supports quantitative multimodal intraprocedural assessment to guide strategy and improve long-term outcomes.