Outcome of atrial fibrillation after mitral valve repair

Objective: The aim of the study was to evaluate the prognostic factors for return to sinus rhythm after mitral valve repair. Method: One hundred ninety-one patients underwent surgery for mitral valve repair, including 142 procedures for valve repair only (74%). The patients with preoperative atrial fibrillation (50.5%) were older, clinically more symptomatic, and had a greater degree of left atrial dilation than the patients who had sinus rhythm. Results: Preoperative cardiac rhythm, the duration of preoperative atrial fibrillation, and a lesser degree of left atrial hypertrophy are significant prognostic factors independent of the maintenance of sinus rhythm. The probability of return to stable sinus rhythm was 93.7% when sinus rhythm was already present before the operation and 80% when atrial fibrillation was intermittent or of less than 1 year's duration; probability declined abruptly for durations over 1 year. No significant difference in patient survival was noted between those who had sinus rhythm (99% +/- 0.9% at 1 year and 86% +/- 6.6% at 5 years) and those who had atrial fibrillation in the preoperative period (95% +/- 3.1% at 1 year and 86% +/- 8.4% at 5 years). In contrast, the postoperative return to sinus rhythm was associated with 99% +/- 0.9% and 94% +/- 4.8% survivals at 1 and 4 years versus 97% +/- 1.5% and 77% +/- 13% in the event of postoperative atrial fibrillation. Conclusion: The aim of restoring postoperative sinus rhythm after mitral valve repair should lead to surgery being conducted on patients who have sinus rhythm or recent-onset atrial fibrillation. Surgery for atrial fibrillation may be of value in patients with a long history of atrial fibrillation, providing that it does not induce prohibitive excess mortality.