Contemporary Surgical Outcomes and Repair Rates in Degenerative Mitral Regurgitation: Real World Insights from the International MITRACURE Registry

OBJECTIVE: Degenerative mitral valve (MV) disease is the leading mitral regurgitation (MR) etiology in Western countries, representing a significant health burden. With the rise of transcatheter therapies, real-world data on surgical management, repair rates, outcomes, and center-level practices are increasingly needed. METHODS: From MITRACURE, a multicenter registry of 40 centers across Canada and France of consecutive adult patients who underwent surgery for MR in 2019, we selected the subset of patients with degenerative MR. RESULTS: MV surgery was performed in 2,135 patients with degenerative MR (70% male, 65±12 years); 37% were in NYHA III/IV, only 17% were considered asymptomatic, and early intervention was performed in only 4%. MV repair rate was 80%, with a 6% intraoperative repair failure rate. In-hospital mortality was 2.3%, 1.4% for repair vs 6.2% for replacement, P<0.0001. Major complications occurred in 20%, higher for replacement and combined procedures. Independent predictors of mortality included NYHA III/IV, type of surgery, and EuroSCORE II. Repair rates declined with age, comorbidities, and complex anatomy, and increased with center volume (68%, 77%, and 84% in low, intermediate, and high-volume centers, respectively; P<0.0001). Sex was not associated with repair rates after adjustment. CONCLUSIONS: In this large real-world cohort from two publicly funded healthcare systems, many patients with degenerative MR were referred late for surgery, and early intervention was rare. While in-hospital mortality was low overall, outcomes varied across subgroups. MV repair declined with age and MV anatomical complexity. High-volume centers had better outcomes, supporting earlier referral, structured pathways, and surgical centralization to optimize care.