Renal dysfunction in cardiac surgery: identifying potential risk factors

Abstract

Aprotinin has been associated with increased renal failure and mortality when used in cardiac surgery. The purpose of this retrospective study was to compare the incidence of renal failure and mortality in our patient population to the published rates, accounting for risk factors associated with renal failure. After IRB approval; using the STS Database and cardiopulmonary bypass pump records, a total of 2292 cardiac patients were identified from January 2004 through June 2008. Forty-nine patients were excluded because they were on renal dialysis preoperatively. There were 1226 coronary artery bypass patients. Patients were separated into groups, according to which antifibrinolytic agent was used. This study included a total of 716 patients, divided into three groups; aprotinin (n = 436), tranexamic acid (n = 61), and off-pump coronary artery bypass (OPCAB) (n = 219). Epsilon aminocaproic acid (AMICAR) was given by the anesthesiologist to the majority of the remaining 510 patients and was not recorded on the bypass record. Therefore, patients given AMICAR were not included in this study. Outcomes included renal dialysis after surgery and mortality. Risk factors were identified and compared to patients in a study published by Mangano in the New England Journal of Medicine (N Engl J Med 2006; 354: 353-365). Aprotinin vs. control group showed no significant difference in risk factors for diabetes mellitus, hypertension, creatinine level above 1.3 mg/dl, or low ejection fraction. The percentage of patients requiring renal dialysis and mortality was less in Medical University of South Carolina (MUSC) patients than the other published study. Overall, the patients in the MUSC study had greater risk factors for renal failure, with the exception of patients with preoperative serum creatinine of >1.3 mg/dl (8.3 vs. 15.1%). This study does not show the same risk for renal failure associated with aprotinin that has been published elsewhere.