Perioperative renal outcome in cardiac surgical patients with preoperative renal dysfunction: aprotinin versus epsilon aminocaproic acid.

Objective: The administration of aprotinin to patients with pre-existing renal dysfunction who are undergoing cardiac surgery is controversial. Therefore, the authors present their experience with the use of aprotinin for patients with preoperative renal dysfunction who underwent elective cardiac surgery requiring cardiopulmonary bypass (CPB).

Design: Retrospective analysis.

Setting: University hospital.

Participants: Consecutive cardiac surgical patients with preoperative serum creatinine (SCr) > or =1.8 mg/dL undergoing nonemergent cardiac surgery requiring CPB.

Interventions: None.

Methods: One hundred twenty-three patients either received epsilon aminocaproic acid (EACA, n = 82) or aprotinin (n = 41) as decided by the attending anesthesiologist and surgeon. Data were collected from the Society of Thoracic Surgeons database and from automated intraoperative anesthesia records. Renal function was assessed from measured serum creatinine (SCr) and calculated creatinine clearances (CrCls). Acute perioperative renal dysfunction was defined as a worsening of perioperative renal function by > or =25% and/or the need for hemodialysis (HD).

Analysis: Data were recorded as mean and standard deviation or percentage of population depending on whether the data were continuous or not. Data were compared by using an analysis of variance, chi-square analysis, Student paired and unpaired t tests, Fisher exact test, Wilcoxon rank sum test, and Mann-Whitney U test. A p value <0.05 was considered significant.

Results: Overall, 32% and 41% of patients had acute perioperative renal dysfunction measured by CrCl and SCr, respectively. Seven patients required HD (5.7%). Six of these 7 had complicated postoperative courses. Of all the variables measured, only the duration of the aortic crossclamp (AoXCl) and CPB were significantly associated with acute perioperative renal dysfunction. Acute perioperative renal dysfunction was associated with increased intensive care unit and hospital stays, postoperative blood transfusion, dialysis, and major infection. Aprotinin patients were significantly older (75.2 v 70.2 years, p < 0.05), had lower left ventricular ejection fraction (44.4% v 49.2%, p < 0.05), a greater preoperative history of congestive heart failure (63 v 44%, p < 0.05), a greater renal risk score (5.8 v 4.9, p < 0.05), and underwent more nonisolated coronary artery bypass graft surgeries (77% v 29%, p < 0.0001). CPB time (126.0 v 96.5 minutes, p < 0.001) and AoXCl duration (100.9 v 78.0 minutes, p < 0.005) were longer in the aprotinin group. Diabetes (60.5% v 41.5%, p < 0.05) and hypertension (90.1% v 73.2%, p < 0.05) were more prevalent in the EACA group. Baseline renal function and renal outcomes were not significantly different between the aprotinin and EACA groups. Six of the 7 patients who required HD received EACA (p = 0.1). The earliest SCr recorded > or =3 months after surgery was significantly lower in the aprotinin group compared with the EACA group (1.8 v 2.2 mg/dL, p < 0.05).

Conclusion: Acute perioperative renal dysfunction was associated with worse patient outcome and longer CPB and AoXCl times. Demographic and surgical variables indicated that the sicker patients undergoing more complex surgeries were more likely to be treated with aprotinin. Although aprotinin patients had a higher renal risk score, the administration of aprotinin did not negatively impact renal outcome.