Acute kidney injury following coronary artery bypass grafting: early mortality and postoperative complications

Abstract

Objectives. To investigate the prognostic importance of acute kidney injury on early mortality, postoperative stroke, and mediastinitis in patients undergoing a first isolated coronary artery bypass grafting. Design. 7594 patients undergoing coronary artery bypass grafting with information on pre- and postoperative serum-creatinine values were included. Patients were classified using the Acute Kidney Injury Network classification. Odds ratios (OR) for mortality and postoperative complications within 60 days of surgery were calculated after adjustment for confounders separately for stage 1 and for stages 2 and 3 together. Results. 1047 (14%) patients developed acute kidney injury. There were 132 (1.7%) deaths, 103 (1.4%) strokes and 118 (1.6%) cases of mediastinitis during follow-up. Among patients in stage 1 the adjusted odds ratio for death was 4.36 (95% confidence interval 2.83–6.71) and for stage 2 plus 3; 21.5 (12.0–38.6) compared to patients without acute kidney injury. Corresponding OR for stroke were 2.34 (1.43–3.82) and 6.52 (2.97–14.3) and for mediastinitis 2.88 (1.84–4.50) and 4.68 (2.07–10.6), respectively. Conclusions. Acute kidney injury following coronary artery bypass grafting is related to postoperative mortality, stroke, and mediastinitis. Patients undergoing coronary artery bypass grafting should be assessed for presence of acute kidney injury postoperatively, in order to predict early prognosis.