Clip It or Let It: The Efficacy of Mitral Valve Transcatheter Edge-to-Edge Repair Versus Conservative Treatment in Reducing Mortality Among Patients With Ischemic Mitral Regurgitation

BACKGROUND: Despite revascularization and optimal medial therapy (OMT) residual ischemic mitral regurgitation (IMR) continues in a self-aggravating vicious cycle to affect prognosis and survival adversely. Mitral valve surgery in combination with coronary artery bypass graft remains a subject of debate due to the absence of a net overall benefit. Mitral valve transcatheter edge-to-edge repair (M-TEER) has been gaining grounds as a viable option from observational studies, but results from randomized controlled trials (RCTs) have yielded mixed results. Thus, this study was conducted to determine whether the current collective data support the efficacy of M-TEER with OMT versus OMT alone in patients with clinically significant IMR. METHODS: A literature search from PubMed/MEDLINE, Cochrane Review Central, Clinical Trials Registry, ResearchGate, Mendeley, and Google Scholar for relevant RCTs and observational studies was conducted and reviewed independently by three reviewers. Published and unpublished studies indexed from inception until 2023 were included. The pooled estimates for the primary outcome of all-cause mortality and secondary outcomes of cardiac mortality and heart failure hospitalizations were measured using R Studio statistical software (R Foundation forStatistical Computing, Vienna, Austria). RESULTS: Seven eligible studies (five observational and two RCTs) allocated 1610 IMR patients to M-TEER + OMT (n = 942) or OMT alone (n = 668). The effect estimate using random-effects model demonstrated M-TEER with OMT to significantly reduce 1-year (odds ratio [OR], 0.67; 95% confidence interval [CI], 0.52–0.86; P = 0.002) and 2-year (OR, 0.50; 95% CI, 0.38–0.67; P < 0.00001) all-cause mortality. Cardiac mortality (OR, 0.58; 95% CI, 0.27–1.23; P = 0.15) and heart failure hospitalization (OR, 0.45; 95% CI, 0.18–1.13; P = 0.09) did not reach statistical significance between the treatment arms. CONCLUSION: In patients with IMR, M-TEER on top of OMT was able to afford a 2-year allcause mortality advantage. KEYWORDS: ischemic mitral regurgitation, mitral valve transcatheter edge-to-edge repair, optimal medical therapy