Postoperative plasma copeptin levels independently predict delirium and cognitive dysfunction after coronary artery bypass graft surgery

Copeptin can reflect individual's stress state and are correlated with poor outcome of critical illness. The occurrence of postoperative delirium (POD) and cognitive dysfunction (POCD) is associated with worse outcome after coronary artery bypass graft (CABG) surgery. The present study aimed to investigate the ability of postoperative plasma copeptin level to predict POD and POCD in patients undergoing CABG surgery. Postoperative plasma copeptin levels of 108 patients were measured by an enzyme-linked immunosorbent assay. It was demonstrated that plasma copeptin levels were substantially higher in patients with POD than without POD (1.8 ± 0.6 ng/mL vs. 1.1 ± 0.3 ng/mL; P < 0.001) and in patients with POCD than without POCD (1.9 ± 0.6 ng/mL vs. 1.1 ± 0.4 ng/mL; P < 0.001). Plasma copeptin level and age were identified as independent predictors for POD odds ratio (OR), 67.386; 95% confidence interval (CI), 12.031–377.426; P < 0.001 and OR, 1.202; 95% CI, 1.075–1.345; P = 0.001] and POCD (OR, 28.814; 95% CI, 7.131–116.425; P < 0.001 and OR, 1.151; 95% CI, 1.030–1.285; P = 0.003) using a multivariate analysis. For prediction of POD, the area under receiver operating characteristic curve (AUC) of the copeptin concentration (AUC, 0.883; 95% CI, 0.807–0.937) was markedly higher than that of age (AUC, 0.746; 95% CI, 0.653–0.825; P = 0.020). For prediction of POCD, the AUC of the copeptin concentration (AUC, 0.870; 95% CI, 0.792–0.927) was markedly higher than that of age (AUC, 0.735; 95% CI, 0.641–0.815; P = 0.043). Thus, postoperative plasma copeptin level may be a useful, complementary tool to predict POD and POCD in patients undergoing CABG surgery.