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 hun dred ninety-one patients underwent surgery for mitral valve repair, in cluding 142 procedures for valve repair only (74%). The patients with preoperative atrial fibrillation (50.5%) were older, clinically more s ymptomatic, and had a greater degree of left atrial dilation than the patients who had sinus rhythm. Results: Preoperative cardiac rhythm, t he duration of preoperative atrial fibrillation, and a lesser degree o f left atrial hypertrophy are significant prognostic factors independe nt of the maintenance of sinus rhythm. The probability of return to st able sinus rhythm was 93.7% when sinus rhythm was already present befo re the operation and 80% when atrial fibrillation was intermittent or of less than 1 year's duration; probability declined abruptly for dura tions over 1 year. No significant difference in patient survival was n oted 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 pr eoperative 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 fibr illation. Conclusion: The aim of restoring postoperative sinus rhythm after mitral valve repair should lead to surgery being conducted on pa tients who have sinus rhythm or recent-onset atrial fibrillation. Surg ery for atrial fibrillation may be of value in patients with a long hi story of atrial fibrillation, providing that it does not induce prohib itive excess mortality.