Background. Physical prehabilitation (preparative rehabilitation) programs may have beneficial effects on enhancing physical strength and functional status before surgery, but their effects on postoperative recovery are unclear.

Objectives. This systematic review investigated the effectiveness of physical prehabilitation programs before cardiac surgery on postoperative recovery and other perioperative outcomes.

Methods. We searched for reports of randomised controlled trials of any prehabilitation programs that included physical activity or an exercise training component in adults undergoing elective cardiac surgery, published in any language, from six bibliographic databases (last search on June 20, 2019). We assessed trials for risk of bias, overall certainty of evidence and quality of intervention reporting using the Cochrane Risk of Bias Assessment Tool, GRADE system and the Template for Intervention Description and Replication checklist and guide, respectively.

Results. All 7 studies (726 participants) were at high risk of bias because of lack of blinding. The quality of prehabilitation reporting was moderate because program adherence was rarely assessed. The timing of prehabilitation ranged from 5 days to 16 weeks before surgery and from face-to-face exercise prescription to telephone counselling and monitoring. We found uncertain effects of prehabilitation on postoperative clinical outcomes (among the many outcomes assessed): perioperative mortality (Peto odds ratio 1.30, 95% confidence interval [CI] 0.28 to 5.95; I²=0%; low-certainty evidence) and postoperative atrial fibrillation (relative risk 0.75, 95% CI 0.38 to 1.46; I²=50%; very low-certainty evidence). However, prehabilitation may improve postoperative functional capacity and slightly shorten the hospital stay (mean difference -0.66 days, 95% CI -1.29 to -0.03; I²=45%; low-certainty evidence).

Conclusion. Despite the high heterogeneity among physical prehabilitation trials and the uncertainty regarding robust clinical outcomes, physical prehabilitation before cardiac surgery seems to enhance selected postoperative functional performance measures and slightly reduce the hospital length of stay after cardiac surgery.