Survival after mitral valve replacement:: Rationale for surgery before occurrence of severe symptoms

Background. This study was undertaken to evaluate survival after mitral valve replacement, with a focus on the impact of age and preoperative symptoms. Methods. Survival was analyzed in 784 patients undergoing mitral valve replacement from 1980 through 2000. Relative survival was estimated by relating the observed survival to the expected survival in a cohort, comparable regarding sex, age group, and calendar period, in the general Swedish population. Results. Early mortality was 9.7%. Relative survival rates after 5, 10, and 15 years were 83%, 70%, and 54%, respectively. The corresponding rates for observed survival were 75%, 56%, and 36%. Advanced New York Heart Association class, but not high age, was a risk factor for early mortality, whereas both factors decreased survival. An association between age and New York Heart Association class was found, the majority of old patients also being severely symptomatic. Patients in New York Heart Association classes I and 11 showed excellent relative survival. Conclusions. Survival is reduced after mitral valve replacement in patients with severe preoperative symptoms, whereas patients with less-severe symptoms show excellent survival. Older patients were more often severely symptomatic at the time of surgery. Irrespective of age, surgery before the occurrence of advanced symptoms should improve the long-term outcome. (C) 2004 by The Society of Thoracic Surgeons.