Risk factors for acute renal failure after heart surgery.

Objective: The aim of the present study was to identify risk factors for acute renal failure in patients with normal levels of serum creatinine who had undergone coronary artery bypass graft (CABG) surgery and/or valve surgery.

Methods: Data from a cohort of 769 patients were assessed using bivariate analyses and binary logistic regression modeling.

Results: Three hundred eighty one patients underwent CABG, 339 valve surgery and 49 had undergone both simultaneously. Forty six percent of the patients were female and the mean age was 57 +/- 14 years (13 to 89 years). Seventy eight (10%) patients presented renal dysfunction postoperatively, of these 23% needed hemodialysis (2.4% of all patients). The mortality for the whole cohort was 10%. The overall mortality for patients experiencing postoperative renal dysfunction was 40% (versus 7%, P < 0.001), 29% for those who did not need dialysis and 67% for those who needed dialysis (P = 0.004). The independent risk factors found were: age (P < 0.000, OR: 1.056), congestive heart failure (P = 0.091, OR: 2.238), COPD (P = 0.003, OR: 4.111), endocarditis (P = 0.001, OR: 12.140), myocardial infarction < 30 days (P = 0.015, OR: 4.205), valve surgery (P = 0.016, OR: 2.137), cardiopulmonary bypass time > 120 min (P = 0.001, OR: 7.040), peripheral arterial vascular disease (P = 0.107, 2.296).

Conclusion: Renal dysfunction was the most frequent postoperative organ dysfunction in patients undergone CABG and/or valve surgery and age, congestive heart failure, COPD, endocarditis, myocardial infarction < 30 days, valve surgery, cardiopulmonary bypass time >120 min, and peripheral arterial vascular disease were the risk factors independently associated with acute renal failure (ARF).