The effect of preoperative atrial fibrillation on survival following mitral valve repair for degenerative mitral regurgitation

Abstract

Objective: There is conflicting evidence with regard to the impact of preoperative atrial fibrillation (AF) on the post mitral valve (MV) repair on the early and late outcome. Methods: A total of 349 patients undergoing various MV repair procedures for degenerative mitral regurgitation (MR) between 1997 and 2003 were studied. Preoperatively, 152 (44%) of these patients were in AF and 197 (56%) patients were in sinus rhythm (SR). The clinical features and the outcome in these two cohorts of patients were compared. Results: The patients in the AF group were older than their counterparts in the SR group (66 ± 7 vs 62 ± 9 years) (p = 0.01), had a higher mean NYHA class score (2.4 ± 0.6 vs 2.2 ± 0.7) (p = 0.04) and were more likely to have impaired left ventricular function (60% vs 36%) (p < 0.0001). A similar proportion of patients in the AF (38%) and SR (30%) groups had additional cardiac surgical procedures (p = 0.12). Operative mortality was 3.9% in AF group versus 0.5% in SR group (p = 0.04), and operative morbidity was 27% versus 17%, respectively (p = 0.03). At latest follow up, 4% of patients that were in SR preoperatively developed AF; conversely, 2% of the patients in the AF group converted to SR. The rates of recurrent grade II or III MR (4% vs 5%) (p = 0.8) and MV re-operation (2.6% vs 2.5%) (p = 1.0) were similar in the AF and SR groups. Kaplan-Meier survival at 7 years was 75 ± 6% versus 90 ± 3% (p = 0.005). On Cox proportional hazards regression model, impaired LV function [(p = 0.02), hazard ratio 0.25 (95% confidence intervals (C.I.) 0.078-0.84)] and AF [(p = 0.03), hazard ratio 2.70 (95% C.I. 1.09-6.68)] were significant adverse predictors of survival. Conclusions: This study shows that in patients undergoing MV repair for degenerative MR, preoperative AF has a major negative impact on the early and late survival. © 2007 European Association for Cardio-Thoracic Surgery.