Transcatheter edge-to-edge mitral valve repair <i>versus</i> medical therapy for secondary mitral regurgitation: a meta-analysis of randomized controlled trials

Secondary mitral regurgitation (SMR) is associated with increased hospitalizations and mortality. Clinical trials comparing mitral valve transcatheter edge-to-edge repair (M-TEER) with guideline-directed medical therapy (GDMT) show conflicting results, but the RESHAPE-HF2 trial offers new insights. This study aims to assess the M-TEER effect in addition to GDMT in reducing all-cause mortality, cardiovascular death, and heart failure hospitalizations (HHF) in patients with SMR when compared to GDMT alone. On September 2, 2024, PubMed, Cochrane CENTRAL, Scopus, and Web of Science were searched for randomized controlled trials comparing M-TEER in addition to GDMT with GDMT in SMR patients with heart failure. A study-level random-effects meta-analysis was conducted using trial-reported point estimates. Seven records from three trials (COAPT, MITRA-FR, RESHAPE-HF2) involving 1426 participants were included. At 24 months, M-TEER (using MitraClip®) significantly reduced the first HHF [hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.45-0.96] and all HHF (HR 0.63, 95% CI 0.49-0.81). However, no significant reduction was observed in all-cause mortality (HR 0.76, 95% CI 0.57-1.01) or cardiovascular death (HR 0.77, 95% CI 0.56-1.06). The intervention group had more patients in the New York Heart Association class I/II at 12 and 24 months but no significant improvement in 6-minute walk test performance at 12 months. High trial heterogeneity requires careful interpretation of pooled estimates. Differences in medical therapy and patient characteristics likely affected outcomes across trials. While M-TEER demonstrates benefits in reducing HHF, its effectiveness in reducing mortality remains inconclusive. The degree of left ventricular enlargement may have influenced outcomes, underscoring the importance of careful patient selection.