Acute renal failure after coronary artery bypass surgery with extracorporeal circulation -- incidence, risk factors, and mortality

Abstract

Objective: To identify the incidence, risk factors, and mortality of acute renal failure (ARF) in patients undergoing myocardial coronary artery bypass surgery with extracorporeal circulation.

Methods: All patients undergoing myocardial coronary artery bypass surgery were prospectively studied, and their clinical and laboratory variables were assessed using uni- and multivariate analysis (logistic regression).

Results: Acute renal failure occurred in 16.1% of the 223 patients studied; 4.9% of patients required dialysis. Risk factors associated with ARF in the univariate analysis were age > 63 years, OR 3.6 (95% CI=1.6 to 8.3); preoperative serum creatinine > 1.2 mg/dL, OR 5.9 (95% CI=2.4 to 14.6); duration of extracorporeal circulation > 90 min, OR 2.1 (95% CI=1.0 to 4.4); use of intraaortic balloon, OR 2.6 (95% CI=1.2 to 5.5); need for inotropic drugs, OR 4.4 (95% CI=1.9 to 10.2). In the multivariate analysis, independent factors associated with ARF were: age > 63 years, OR 3.0 (95% CI=1.3 to 7.2); preoperative serum creatinine > 1.2 mg/dL, OR 4.3 (95% CI=1.6 to 11.4); need for inotropic drugs, OR 3.2 (95% CI=1.3 to 8.0). Mortality in the patients with ARF was 25.0% compared with 1.1% in those without ARF and 63.6% in those who required dialysis.

Conclusion: Acute renal failure after myocardial coronary artery bypass surgery is a frequent complication associated with a high mortality rate. The independent risk factors are age, previous renal failure, and the need for inotropic drugs.