Late results of valve replacement and factors influencing survival in patients with severe chronic mitral regurgitation.

Between July 1967 and September 1981 50 patients with isolated severe mitral regurgitation underwent mitral valve replacement. There were 29 males and 21 females (mean age 52 years). The aetiology of the valve lesion was rheumatic in 14 patients (mean age 42 years) and non-rheumatic in 36 patients (mean age 56 years). At the time of operation 36 patients (72%) were in class 3 or 4 of the New York Heart Association classification (mean duration of symptoms 20 months). Pre-operative ejection fraction was normal in only four patients (8%) and was below 0.50 in 27 patients (54%). There were two early deaths (4%) within one month of operation, and 17 late deaths (34%) during a follow-up period of four months to 10 years (mean 43 months). Actuarial analysis showed a 71% survival at five years and a 62% survival at 10 years after valve replacement. Of the 31 current survivors, 22 (71%) are in class 1 of the New York Heart Association classification, and all but two patients showed significant improvement in symptoms. Significant morbidity after operation occurred in 10 patients (20%) and was largely related to problems with anticoagulant control. Analysis of factors which may influence survival, showed that age greater than 55 years and parameters of left ventricular geometry, demonstrated by angiography, were the major determinants of survival.