Background: Elderly patients are more likely to have adverse complications after coronary artery bypass grafting (CABG). There are few studies on the risk factors of acute kidney injury (AKI) after surgery in elderly patients, especially in the Asian population. This study retrospectively analyse the risk factors of AKI in Chinese elderly patients after CABG, and establish a risk prediction model to detect these risk factors early and take active intervention measures.
Methods: A total of 432 patients were included in this study from 2018 to 2019. AKI was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The patients were divided into AKI group and non AKI group. Multivariate logistic regression analysis was used to screen out the factors with P < 0.05. The receiver operating characteristic (ROC) curve was made for the predictive risk model. At the same time, the incidence of complications after CABG was compared between the two groups.
Results: Of 432 patients in the study, 119 (27.5%) developed AKI. The estimated glomerular filtration rate (eGFR), ≥ 3 coronary anastomoses, intra-aortic balloon pump (IABP) implantation and ventilation time were independent risk factors for AKI. The area of the ROC curve was (0.702, 95% confidence interval (CI) [0.643-0.761], P < 0.001). There were 7 deaths in the AKI group, which was significantly higher than that in the non AKI group. In addition, in the reoperation and postoperative myocardial infarction, the AKI group was also higher than the non AKI group.
Conclusion: The eGFR, ≥ 3 coronary anastomoses, IABP implantation and ventilation time are independent risk factors for AKI in elderly patients undergoing coronary artery bypass grafting. Early discovering these risk factors and taking intervention measures are helpful to reduce the occurrence of AKI after CABG and improve the prognosis of patients.