Relationship between cardiac rehabilitation and survival after acute cardiac hospitalization within a universal health care system

Background The magnitude and mechanisms of survival benefit associated with cardiac rehabilitation services among real-world populations within a universal health care system remain unclear. Methods This retrospective matched cohort study compared the long-term survival of 2042 cardiac rehabilitation participants with 2042 matched controls after an index acute cardiac hospitalization between 1999 and 2003, in Ontario, Canada. Each patient survived at least 1 year without recurrent admissions after discharge from the index hospitalization, and was followed for a mean of 5.25 years. Additional matching criteria included the type of sentinel cardiac events, age, sex, socioeconomic status, geography, previous cardiac and noncardiac hospitalizations. A Cox proportional hazards model further adjusted for baseline cardiovascular risk factors and process factors, cardiovascular risk-factor progression, downstream coronary procedure and evidence-based pharmacotherapy utilization. Results Cardiac rehabilitation participation was associated with a 50% lower mortality rate (2.6 vs. 5.1%, P<0.001) as compared with population-matched controls. Statistically significant mortality benefits were observed among high-risk patients, and there was no significant interaction among age, cardiac rehabilitation participation, and survival (P=0.22). Associated survival advantages were not meaningfully altered after adjustment for cardiovascular risk-factor progression or the downstream utilization rates of cardiac procedures and evidence-based cardiovascular therapies; survival benefits predominantly applied to those patients that were most compliant with the program. Conclusion Cardiac rehabilitation is associated with significant long-term survival advantages after index cardiovascular hospitalizations. Despite universal access to medical care, such survival advantages seem to be mediated by compliant behaviors more so than by ancillary health service or evidence-based pharmacotherapy utilization. Eur J Cardiovasc Prev Rehabil 16:102-113 (C) 2009 The European Society of Cardiology