Cardiac rehabilitation and survival in patients with left ventricular systolic dysfunction

Background Exercise training, the major component of cardiac rehabilitation (CR), has been shown in previous trials to improve many pathophysiologic c hanges Found in patients with left ventricular systolic dysfunction, it rem ains unproven whether exercise training improves survival. Methods By using the Duke Databank for Cardiovascular Disease, we identifie d patients with an election fraction less than or equal to 40% and no recen t myocardial infarction, congenital heart disease, or primary valvular dise ase who survived 230 days after a cardiac catheterization (n = 1902). Parti cipation in CR (n = 70) was identified through computer billing records. We developed a multivariable Cox proportional hazards regression model to est imate survival by using variables known to be independent predictors of sur vival in patients with systolic dysfunction. Results Patients participating in CR were less likely to be Female or black and more likely to have a history consistent with ischemic cardiomyopathy. Participation in CR was associated with significantly improved survival af ter adjustment for baseline characteristics (hazard ratio, 0.39; 95% confid ence interval, 0.15 to 0.62, P < .0001). Survival increased when patients p articipated in 26 CR sessions (hazard ratio, 0.10; 95% confidence interval, 0.03 to 0.39; P < .0001). Conclusions Participation in CR was associated with improved survival for p atients with cardiomyopathy. There appears to be a dose response with impro ved survival benefit for patients with left ventricular systolic dysfunctio n participating in cardiac rehabilitation.