Degenerative mitral regurgitation: When should we operate?

Background. Left untreated, severe mitral regurgitation in asymptomatic patients can lead to irreversible cardiac damage, which can develop with little warning. Over the period of this study, we have tended to operate earlier in the disease process and on less symptomatic patients. We report here our experience. Methods. Between January 1985 and June 1996, 710 patients with mitral regurgitation underwent operations. Three hundred twenty-nine (213 male and 116 female with a mean age of 65.5 years) had degenerative mitral valve disease and of this group, 169 patients underwent repair and 160, replacement. Results. The overall operative mortality was 4 patients (1.2%). There were no operative deaths among patients having isolated mitral valve repair. Survival at 1 year, 5 years, and 10 years was 94% ± 1.4% (± the standard error of the mean), 77% ± 2.9%, and 41% ± 5.8%, respectively. Survival was significantly better in the group having repair (p < 0.05). Ten patients (6%) in the repair group and 13 (8%) in the replacement group required reoperation. Increased age, worse left ventricular function, type of operation (replacement worse than repair), and increased left ventricular size were significantly associated with poorer survival. Conclusions. These data confirm the superior results achieved with mitral valve repair and support early mitral valve repair before functional deterioration.