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

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.