Cardiac rehabilitation for patients having cardiac surgery: a systematic review.

Introduction: Cardiac rehabilitation (CR) is recommended for all cardiac patients including patients after cardiac surgery. Since the effect of CR after cardiac surgery has not been well established yet, we conducted a systematic review on the effects of CR for patients after cardiac surgery compared to treatment as usual.
Evidence Acquisition: A systematic review of randomized clinical trials (RCTs), quasi-randomized and prospective observational studies in The Cochrane Library, PubMed/MEDLINE and EMBASE was undertaken until October 18th, 2017. Adults after any kind of cardiac surgery were included. Primary outcome was all-cause mortality, other outcomes were serious adverse events, health-related quality of life, work participation, functioning and costs/cost-effectiveness. Risk of bias was evaluated, and the quality of evidence was assessed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria.
Evidence Synthesis: Eighteen RCTs and 15 observational studies were included. Low risk of bias was only observed in one observational study. Meta-analysis of RCTs suggested no significant difference of CR compared to control on mortality (random-effects relative risk (RR) 0.93 (95% CI: 0.40-1.81), while observational studies suggested statistically significant beneficial effect associated with CR (random-effects RR=0.49, 95% CI: 0.35 - 0.68). CR did not significantly affect any of the other outcomes. Due to the limited data TSA could not be performed.
Conclusions: The body of evidence does not allow us to reach any reliable conclusions about the effectiveness of CR following cardiac surgery. Future trials need to be conducted with low risks of bias and clearly defined outcomes.