Aprotinin use in cardiac surgery patients at low risk for requiring blood transfusion

STUDY OBJECTIVES: To determine if aprotinin is safe and effective in patients at low risk for requiring blood transfusion after cardiac surgery by evaluating whether there is any significant difference in blood product use or other significant clinical outcomes between patients who received aprotinin versus those who did not. DESIGN: Retrospective review. SETTING: Inpatient community nonteaching hospital. PATIENTS: Three hundred thirty-five patients who underwent primary cardiac surgery involving cardiopulmonary bypass between November 1, 2003, and December 31, 2005, and were considered at low risk for requiring postoperative blood transfusion; 162 patients received aprotinin and 173 patients received aminocaproic acid (control). MEASUREMENTS AND MAIN RESULTS: Comparison of patients in the aprotinin group versus those in the aminocaproic acid group revealed no difference in total donor exposures to blood products (1.86 vs 1.16 units/patient, p=0.07), total packed red blood cells (PRBCs) received (1.25 vs 0.86 units/patient, p=0.09), postoperative donor exposures to blood products (0.91 vs 0.48 unit/patient, p=0.13), or postoperative PRBCs received (0.61 vs 0.40 unit/patient, p=0.23). No difference was noted in any other clinical outcome in the aprotinin group versus the aminocaproic acid group, including postoperative azotemia (13.0% vs 10.4%, p=0.46), new onset of atrial fibrillation (14.8% vs 15.0%, p=0.95), myocardial infarction, stroke, or death. Mean +/- SD total hospital length of stay was similar in the aprotinin group versus the aminocaproic acid group (8.1 +/- 3.8 vs 7.4 +/- 2.8 days, p=0.08), but length of stay from surgery to discharge was longer in the aprotinin group than in the aminocaproic acid group (5.9 +/- 0.17 vs 5.4 +/- 0.12 days, p=0.032). CONCLUSION: Although aprotinin appeared to be safe in this low-risk patient population, it was not more effective than aminocaproic acid in reducing blood product use after cardiac surgery. More robust evidence is needed from a controlled randomized trial to demonstrate the safety, efficacy, and pharmacoeconomic benefit of aprotinin.