Time-Dependent Associations of Structural and Electrical Failure with Survival after Mitral Valve Repair and Concomitant Atrial Fibrillation Ablation for Degenerative Mitral Valve Disease: A Single-Center Retrospective Cohort Study in South Korea.

BACKGROUND: We examined associations of structural and electrical failure with long-term survival after mitral repair with atrial fibrillation (AF) ablation for degenerative mitral prolapse, using time-dependent modeling. METHODS: We analyzed 300 consecutive patients (age, 59.4±11.9 years; 34.7% female) undergoing degenerative mitral prolapse repair with surgical ablation. Structural failure was defined as postoperative severe mitral regurgitation (MR); electrical failure was defined as AF recurrence beyond a 3-month blanking period. Structural and electrical failures were modeled as time-varying covariates in Cox proportional hazards models evaluating mortality. Bidirectional time-dependent and landmark analyses assessed temporal interdependence. RESULTS: During follow-up (median, 6.3 years), structural and electrical failures occurred at 4.1% and 5.7% per patient-year, respectively; death occurred at 1.1%/patient-year. Structural failure was independently associated with tricuspid regurgitation (TR) velocity (adjusted hazard ratio [aHR], 2.94; 95% confidence interval [CI], 1.79-4.83) and anterior leaflet prolapse (aHR, 3.10; 95% CI, 1.18-8.12). Electrical failure was independently associated with age (aHR, 1.53; 95% CI, 1.19-1.98), left atrial diameter (aHR, 1.06; 95% CI, 1.04-1.08), and severe TR (aHR, 6.24; 95% CI, 2.15-18.11). In the time-dependent analysis, severe MR independently predicted mortality (aHR, 2.54; 95% CI, 1.01-6.38), whereas AF recurrence did not (aHR, 0.97; 95% CI, 0.24-3.97). Bidirectional analyses showed no significant temporal association between structural and electrical failures. CONCLUSION: Among patients with degenerative mitral prolapse undergoing mitral repair with concomitant AF ablation, structural valve failure, but not electrical recurrence, was associated with increased long-term mortality. Structural and electrical failures showed no significant temporal association.