Efficacy of Prehabilitation Before Cardiac Surgery: A Systematic Review and Meta-analysis.

Only six studies were included, most of them small: individual samples ranged from 17 to 246 people, five were single-centre, and one was a subanalysis of an ongoing trial. The studies disagreed substantially with one another. Differences between studies accounted for 78% of the variation in walking distance straight after the programme and 92% of the variation in length of stay. Nobody could be blinded to whether they were doing prehabilitation. Every included study was rated at high risk of performance bias, only two of the six were rated low risk for how outcomes were assessed, and one was rated high risk. Programmes varied widely in length (5 days to 8 weeks), frequency (two to seven sessions a week), session length (35 to 90 minutes) and intensity, and intensity was set in different ways across studies. Five of the six programmes combined exercise with education and/or psychological support, and only one used exercise alone, so the effect of exercise by itself could not be estimated. Timed Up and Go, 5-metre gait speed, the Short Physical Performance Battery, quality of life and exercise capacity could not be pooled because of missing data in the original papers. Publication bias was not checked because fewer than ten studies were included. Follow-up varied from 0 to 6 weeks to 3 to 12 months after surgery, so the pooled follow-up result mixes different time points. The reduction in atrial fibrillation comes from a subgroup of an overall null result; the authors state it does not allow generalisation.

The authors state that financial disclosure statements were obtained and that no conflicts of interest were reported by the authors or by anyone in control of the content of the article. No funding source is named in the text provided.

Do not tell patients that the exercise programme itself shortened their hospital stay or got them walking further. Five of the six programmes also included education or psychological support, and the authors could not separate the exercise from the rest, so the results belong to the whole package rather than to exercise alone. The walking gain was also no longer statistically significant at later follow-up.