Effects of cognitive training on cognitive function in patients after cardiac surgery: A systematic review and meta-analysis of randomized controlled trials

Background: Postoperative cognitive deficits frequently occur in patients undergoing cardiac surgery, leaving them with reduced cognitive function. Cognitive training has been shown to improve cognitive function, however, the role in patients after cardiac surgery is unclear. In this study, we aimed to evaluate the effectiveness and safety of cognitive training in patients undergoing cardiac surgery. Method: A systematic search of PubMed, Embase, Cochrane Library, CINAHL, Ovid Medline, Web of Science, CNKI, and Wanfang was conducted until March 2024. The risk of bias was assessed using the Cochrane Risk of Bias Tool. Data were meta-analyzed using RevMan 5.4 software. Potential bias and reliability of evidence were fairly assessed by using the Cochrane risk of bias method and the GRADE evidence grading method. Results: A total of 16 studies involving 1335 cardiac surgery patients were included in this study. Compared with the control group, the cognitive training group had a significantly lower incidence of postoperative cognitive dysfunction (RR 0.35, 95% CI 0.18–0.65, P = .001), significantly improved cognitive function (MD 2.54, 95% CI 1.27–3.81, P < .001), and a significantly higher quality of life-mental component (MD 5.22, 95% CI 2.32–8.13, P < .001), anxiety (MD −6.05, 95% CI −10.96 to −1.15, P = .02) and depression (MD −3.97, 95% CI −7.15 to −0.80, P = .01) were significantly improved between groups. However, the differences were not statistically significant for postoperative delirium (RR 1, 95% CI 0.38–2.65, P = 1.00) and postoperative hospitalization (MD −0.95, 95% CI −2.90 to 1.00, P = .34). Conclusions: The present study, based on a low to moderate quality of evidence, suggests that cognitive training improves cognitive functioning, reduces the incidence of postoperative cognitive dysfunction, and has a positive impact on anxiety and depression in patients undergoing cardiac surgery. However, current evidence does not allow for the determination of effects on quality of life, postoperative delirium, and postoperative length of stay.