Preprocedural New York Heart Association Class IV Independently Predicts Mortality After Effective Edge-To-Edge Repair for Primary Mitral Regurgitation.

Background In patients with primary mitral regurgitation (MR) (PMR), advanced symptoms classified as New York Heart Association (NYHA) class IV are typically driven by valve deterioration. Transcatheter edge-to-edge repair (mitral valve transcatheter edge-to-edge repair [M-TEER]) reliably achieves effective reduction of mitral regurgitation in high-risk patients. However, whether or not preprocedural NYHA class IV continues to predict outcomes after successful MR reduction remains unclear.Methods The Outcomes of Patients tReated wIth Mitral Transcatheter Edge-to-edge Repair for Primary Mitral Regurgitation Registry includes PMR patients undergoing M-TEER at 27 international sites between 2009 and 2023. Clinical outcomes were compared between patients in NYHA class IV and those in NYHA class II/III.Results A total of 2528 patients were included (median age 82 years [interquartile range (IQR) 76-85], 45.9% female), and 19.7% presented in NYHA class IV. Baseline left ventricular ejection fraction and right ventricular function did not differ significantly between groups. Procedural success (residual MR ≤ 1+: 66.7% vs. 64.6%, p = 0.55) and 2-year rehospitalization rates (17.9% vs. 20.4%, log-rank p = 0.78) were comparable. In contrast, 2-year all-cause mortality was higher in NYHA class IV patients (31.8% vs. 21.1%, log-rank p < 0.0001). Multivariable Cox regression confirmed preprocedural NYHA class IV as an independent predictor of mortality (hazard ratio [HR] 1.75; 95% CI 1.32-2.31; p < 0.001).Conclusions In PMR, preprocedural NYHA class IV remains an independent predictor of all-cause mortality after effective MR reduction with M-TEER, despite comparable postprocedural results.