Risk factors and outcomes of acute renal failure after open cardiac surgery

Abstract

The incidence, risk factors, and outcome of acute renal failure following open cardiac surgery were assessed prospectively in 5,164 consecutive patients undergoing open heart surgery between March 2006 and February 2011. Acute postoperative renal failure (creatinine >1.5 mg·dL−1 within 3 days after surgery) developed in 64 (1.2%) patients with normal preoperative renal function (study group). A control group of 238 cardiac surgery patients who had postoperative creatinine levels ≤1.5 mg·dL−1 were selected randomly during the study period. A prospective case-control analysis of these 302 patients was performed. The mean age was 56.3 ± 12.5 years; 191 (63.2%) were men and 111 (36.8%) were women. Pre-, intra- and postoperative risk factors for acute renal failure were evaluated. Of the patients who developed acute renal failure, 12 (18.8%) died postoperatively, which was significantly higher than the 2.1% mortality among those without acute renal failure. Five of the 10 patients (50%) who needed dialysis died. The most significant prognostic factor for mortality was cardiac dysfunction. This study confirmed that impairment of renal function after cardiac surgery is uncommon without preoperative renal impairment, but carries an increased mortality rate.