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.