Determinants of early decline in ejection fraction after surgical correction of mitral regurgitation

Objective: We sought to echocardiographically examine the early changes in left ventricular size and function after mitral valve repair or replacement for mitral regurgitation caused by leaflet prolapse. Methods: Preoperative and early postoperative echocardiograms of 861 patients with mitral regurgitation caused by leaflet prolapse who underwent mitral valve repair or replacement (with or without coronary revascularization) were studied. Among the patients, 625 (73%) were men and 779 (90%) had mitral valve repair. Results: The rate of valve repair increased from 78% in the first decade of the study to 92% in the second decade. At early echocardiography (mean, 5 days postoperatively), we observed significant decreases in left ventricular ejection fraction (mean, -8.8) and left ventricular end-diastolic dimension (mean, -7.5). The magnitude of the early decline in ejection fraction was similar in patients who had mitral valve repair and replacement. The decrease in postoperative ejection fraction was independently associated with a lower preoperative ejection fraction, the presence of atrial fibrillation, advanced New York Heart Association functional class, greater left ventricular end-diastolic and end-systolic dimensions, and larger left atrial size. Conclusion: Surgical correction of mitral regurgitation results in an early decrease in ejection fraction, particularly in symptomatic patients with increased left heart dimensions.