Functional mitral valve regurgitation outcomes by treatment modality: a systematic review and meta-analysis of reconstructed survival data

Functional mitral regurgitation (FMR) carries poor prognosis, and optimal management remains debated. Mitral Transcatheter Edge-to-Edge Repair (MTEER) is an alternative to surgical repair (SMVR) or optimized medical therapy (OMT), but long-term outcomes are uncertain. PubMed, Embase, Scopus, and the Cochrane Library were searched for studies reporting Kaplan–Meier curves of MTEER, SMVR, or OMT in FMR. Individual patient data (IPD) were reconstructed using the Liu method with accuracy checks. Pooled IPD were analyzed with Cox and time-varying Cox models, landmark, time-restricted, and restricted mean survival time analyses. Sixteen studies ( n = 4,570) were included. Patients undergoing MTEER were older and higher risk, with greater prevalence of atrial fibrillation, prior myocardial infarction, chronic kidney disease, higher EuroSCORE, and more frequent NYHA class ≥ III compared with SMVR. Over up to 60 months, both MTEER (HR: 0.65; 95% CI: 0.57–0.75; p < 0.001) and SMVR (HR: 0.39; 95% CI: 0.33–0.46; p < 0.001) significantly reduced all-cause mortality versus OMT, whereas MTEER carried higher mortality risk than SMVR (HR: 1.68; 95% CI: 1.43–1.97; p < 0.001). MTEER was less effective than SMVR in reducing recurrent MR > 2 (HR: 3.31; 95% CI: 1.62–6.75; p < 0.001) and reoperation (HR: 4.62; 95% CI: 2.22–9.61; p < 0.001). In contrast, MTEER reduced hospitalization risk by 30% compared to OMT (HR: 0.70; 95% CI: 0.64–0.77; p < 0.001) and decreased MACE by 21% (HR: 0.79; 95% CI: 0.73–0.84; p < 0.001). MTEER improves survival and reduces hospitalization and MACE compared with OMT but is less durable than SMVR, with higher risks of recurrent MR, reoperation, and late mortality.