When Mitral Repair Fails: Understanding Recurrence, Risk Factors, and Treatment Choices

Background: Reintervention after mitral valve repair represents a relevant clinical challenge, yet the mechanisms and timing of repair failure remain incompletely defined. Understanding how the interval between index repair and reoperation affects failure mechanisms and the feasibility of repeat repair may help refine surgical strategies. Methods: We retrospectively analyzed 194 patients undergoing repeat mitral valve surgery between 2010 and 2025 after prior repair. Median age was 70 years and 61.3% were male. Patients were stratified by time to reoperation: 0-5 years (n = 91), 6-10 years (n = 42), and >10 years (n = 61). Median left ventricular ejection fraction was 58%, atrial fibrillation prevalence 32.5%, minimally invasive approach 21.6%, and EuroSCORE II 4.8%. Results: Baseline characteristics and operative risk were comparable across groups. However, mechanisms of repair failure differed significantly. Early failures were more commonly due to recurrent leaflet prolapse (47.8%), whereas late failures showed a higher incidence of mitral stenosis (63.9%). The rate of repeat mitral repair decreased over time, being higher in early failures compared with intermediate and late failures (17.6% vs. 14.3% vs. 8.2%). Conclusions: Timing of mitral repair failure is associated with distinct mechanisms and influences surgical management. Early failures are more frequently related to prolapse recurrence and are more amenable to re-repair, whereas late failures are characterized by structural degeneration and more often require valve replacement.