Impact of Residual Mitral Regurgitation on Survival After Transcatheter Edge-to-Edge Repair for Secondary Mitral Regurgitation

Y OBJECTIVES The aim of this study was to assess the impact of residual mitral regurgitation (resMR) on mortality with respect to left ventricular dilatation (LV-Dil) or right ventricular dysfunction (RV-Dys) in patients with secondary mitral regurgitation (SMR) who underwent mitral valve transcatheter edge-to-edge repair (TEER). BACKGROUND The presence of LV-Dil and RV-Dys correlates with advanced stages of heart failure in SMR patients, which may impact the outcome after TEER. METHODS SMR patients in a European multicenter registry were evaluated. Investigated outcomes were 2-year all-cause mortality and improvement in New York Heart Association functional class with respect to MR reduction, LV-Dil (defined as LV end-diastolic volume >= 159 ml), and RV-Dys (defined as tricuspid annular plane systolic excursion-to-systolic pulmonary artery pressure ratio of <0.274 mm/mm Hg). RESULTS Among 809 included patients, resMR <= 1+ was achieved in 546 (67%) patients. Overall estimated 2-year mortality rate was 32%. Post-procedural resMR was significantly associated with mortality (p = 0.031). Although the improvement in New York Heart Association functional class persisted regardless of either LV-Dil or RV-Dys, the beneficial treatment effect of resMR <= 1+ on 2-year mortality was observed only in patients without LV-Dil and RV-Dys (hazard ratio: 1.75; 95% confidence interval: 1.03 to 3.00). CONCLUSIONS Achieving optimal MR reduction by TEER is associated with improved survival in SMR patients, especially if the progress in heart failure is not too advanced. In SMR patients with advanced stages of heart failure, as evidenced by LV-Dil or RV-Dys, the treatment effect of TEER on symptomatic improvement is maintained, but the survival benefit appears to be (C) 2021 by the American College of Cardiology Foundation.