Congestive heart failure after surgical correction of mitral regurgitation. A long-term study.

BACKGROUND: In patients with mitral regurgitation, surgical intervention produces immediate improvement in symptoms, but the long-term incidence and significance of postoperative congestive heart failure are unknown. METHODS AND
RESULTS: The long-term outcome of 576 operative survivors of surgical correction of pure mitral regurgitation performed between 1980 and 1989 was analyzed. Survival was 77 +/- 2% and 56 +/- 3% at 5 and 10 years, respectively. Cumulative incidence of congestive heart failure was 23 +/- 2%, 33 +/- 3%, and 37 +/- 3% at 5, 10, and 14 years, respectively. Survival after the first episode of congestive heart failure was dismal, 44 +/- 4% at 5 years. Cause of congestive heart failure was left ventricular dysfunction in two thirds of the patients and valvular dysfunction in the other third. With multivariate analysis, the independent predictors of postoperative heart failure were preoperative ejection fraction (P = .0001), coronary artery disease (P = .0017), and New York Heart Association functional class (P = .012), with borderline value for atrial fibrillation (P = .10). The performance of valve repair was independently predictive of a lower incidence of the combined end point of death and heart failure (P = .001), compared with valve replacement.
CONCLUSIONS: Congestive heart failure frequently occurs late after surgical correction of mitral regurgitation and portends dismal prognosis. This complication is due most often to left ventricular dysfunction; its main determinant is decreased left ventricular function preoperatively. These data should lead to earlier indication of surgical correction of mitral regurgitation, before left ventricular dysfunction occurs.