Percutaneous Transcatheter Edge-to-Edge Repair for Functional Mitral Regurgitation in Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials With Reconstructed Time-to-Event Data

Abstract

Background: Mitral transcatheter edge-to-edge repair (TEER) is approved for patients with severe functional mitral regurgitation (FMR) beyond optimal medical therapy (OMT). Aims: We aimed to assess TEER's efficacy beyond OMT in patients with severe FMR. Methods: A systematic review and meta-analysis were conducted, including randomized controlled trials from PubMed, Cochrane, Scopus, and EMBASE up to September 2024. Primary outcome: heart failure hospitalization (HFH); secondary outcomes: cardiovascular (CV) mortality, all-cause mortality, and Kansas City Cardiomyopathy Questionnaire (KCCQ) scores. Time-to-event data from Kaplan−Meier curves were reconstructed for individual patient data. Results: Three studies (1423 patients) were included. TEER significantly reduced HFH (RR 0.73, 95% CI 0.58−0.92, p < 0.01) and CV mortality (RR 0.79, 95% CI 0.66−0.95, p = 0.01), and improved KCCQ scores (mean difference 14.32, 95% CI 10.85−17.80, p < 0.01) compared to OMT. No significant difference was found for all-cause mortality (RR 0.80, 95% CI 0.63−1.02, p = 0.07). Prognostic meta-analysis showed a 34% reduced risk of HFH (HR 0.66, 95% CI 0.45−0.96, p = 0.03), but no effect on all-cause or CV mortality. Reconstructed Kaplan−Meier analysis confirmed a 34% reduced risk of HFH (HR 0.65, p < 0.001), with effect attenuation after 15 months in landmark analysis (HR 0.64, p = 0.07). RMST analysis showed a 2.9-month longer HFH-free survival with TEER (p < 0.01). Conclusion: In patients with FMR, TEER significantly reduces HFH, improves functional status, and lowers CV mortality at 24 months but does not significantly affect all-cause mortality. The device group experienced a modest, but significant, 2.9-month longer HFH-free survival compared to the control group. However, the reduction in HFH showed attenuation beyond 15 months.