Effects of postoperative cognitive training on neurocognitive decline after heart surgery: a randomized clinical trial

Following cardiac surgery, postoperative cognitive decline (POCD) is a common complication that can impair the quality of life and increase mortality. The aim of this study was to investigate whether early postoperative cognitive training can decrease POCD after cardiac surgery.The study was a multi-centred, two-arm, randomized (1:1 ratio), controlled trial involving older patients undergoing elective heart valve surgery with extracorporeal circulation. Recruitment took place at the Department of Cardiac Surgery of the Kerckhoff-Clinic in Bad Nauheim (Germany) and the University-Hospital in Giessen (Germany). The patients were randomized to either a paper-and-pencil-based cognitive training group or a standard rehabilitation care control group. The cognitive training started 1 week after surgery and lasted about 3 weeks until discharge from rehabilitation. To detect POCD, neuropsychological functions were assessed prior to surgery, upon discharge from rehabilitation (primary outcome), and 3 months after discharge (secondary outcome). Data were primarily analysed in a per-protocol fashion.The frequency of POCD at discharge from rehabilitation (training group, n = 37; control group, n = 44) was 50% in the control group and 19% in the training group (χ2[1] = 8.45, P = 0.004; odds ratio = 4.29, 95% confidence interval [1.56-11.80]). Three months after the cognitive training (training group, n = 33; control group, n = 34), POCD frequency was 29% in the control group and 6% in the training group (χ2[1] = 6.21, P = 0.013; odds ratio = 6.46, 95% confidence interval [1.29-32.28]).Since our cognitive training showed beneficial effects, it could be a promising method to prevent POCD.