New-Onset Postoperative Atrial Fibrillation Predicts Late Mortality After Mitral Valve Surgery

Background. New-onset postoperative atrial fibrillation (POAF) is a common rhythm disturbance after mitral valve surgery. In this study we investigated the independent effect of POAF on early and late mortality after mitral valve surgery. Methods. Data of patients who consecutively underwent mitral valve surgery with or without concomitant coronary or tricuspid valve surgery between January 2003 and June 2010 were prospectively collected. The study included 856 patients with preoperative sinus rhythm, and no history of atrial fibrillation. Logistic regression and Cox proportional hazard analyses were performed to investigate independent predictors of early and late mortality. Propensity score adjustment was performed to reduce the effect of confounders. Results. The median follow-up was 3.1 years (range, 0 to 7.4 years). The POAF was documented in 361 patients (42%). Early mortality did not differ in patients with and without POAF (p = 0.93). Postoperative atrial fibrillation was not identified as predictor for early mortality. Late survival was worse in patients with POAF (log-rank, p <0.001). Multivariate and propensity score adjusted Cox proportional hazard analyses demonstrated that POAF was an independent predictor for late mortality with hazard ratios of 2.09 and 1.61 (p = 0.001 and p = 0.033, respectively). Conclusions. Postoperative atrial fibrillation is an independent predictor for late all-cause mortality after mitral valve surgery but not for early all-cause mortality. (Ann Thorac Surg 2011;92:2091-6)