The effect of coronary angiography timing and use of cardiopulmonary bypass on acute kidney injury after coronary artery bypass graft surgery

Abstract Objective Acute kidney injury is a common but serious complication of coronary artery bypass grafting. We investigated whether the effect of the timing of coronary angiography on acute kidney injury after coronary artery bypass grafting is influenced by the use of cardiopulmonary bypass. Methods We included, retrospectively, 2371 patients who underwent coronary artery bypass grafting whether cardiopulmonary bypass was used (on-pump coronary artery bypass) or not (off-pump coronary artery bypass). Postoperative acute kidney injury was defined by the consensus Kidney Disease: Improving Global Outcomes Definition and Staging criteria. Multivariate logistic regression and propensity score analysis were performed to evaluate the association of the time interval between coronary angiography and coronary artery bypass grafting with postoperative acute kidney injury. Results The incidence of acute kidney injury was higher in patients who underwent coronary angiography 7 days or less before coronary artery bypass grafting than in those who underwent it more than 7 days before coronary artery bypass grafting (42.7% vs 38.5%, P = .037). There was significant interaction between the timing of coronary angiography and the use of cardiopulmonary bypass for postoperative acute kidney injury ( P = .019). The time interval between coronary angiography and surgery was independently associated with postoperative acute kidney injury in patients undergoing on-pump coronary artery bypass only. In an adjusted propensity score model, coronary angiography within 7 days of on-pump coronary artery bypass was a predictor of postoperative acute kidney injury (odds ratio, 1.742; 95% confidence interval, 1.144-2.653; P = .010). Conclusions A shorter interval between coronary angiography and surgery influenced the occurrence of acute kidney injury in patients undergoing on-pump coronary artery bypass. However, the interval is not an independent risk factor for the development of postoperative acute kidney injury in patients who undergo off-pump coronary artery bypass.