Epsilon-aminocaproic acid in coronary artery bypass graft surgery: preincision or postheparin?

BACKGROUND Epsilon-aminocaproic acid (epsilon-ACA), an antifibrinolytic agent, is used in cardiac surgery to decrease postoperative bleeding. Theoretical concerns exist about the potential for epsilon-ACA to contribute to thrombotic complications. For this reason epsilon-ACA administration is sometimes delayed until after heparinization. This study investigated the impact of the timing of epsilon-ACA administration on its efficacy. METHODS In this double-blind study, 90 patients undergoing primary coronary artery bypass graft surgery were prospectively randomized to receive either epsilon-ACA commencing prior to skin incision (bolus 150 mg/kg, followed by an infusion at 15 mg x kg(-1) x hr(-1), epsilon-ACA commencing after heparin (same doses), or placebo. All infusions were terminated at the end of cardiopulmonary bypass. Criteria for the transfusion of blood products were standardized. Postoperative chest tube drainage (at 6 h, 12 h, and at chest tube removal) and blood transfusion requirements of the three groups were compared. RESULTS At all time intervals, the placebo group had significantly greater chest tube drainage than either of the two epsilon-ACA groups (P < 0.005). At no time did a significant difference exist between the two epsilon-ACA groups. A trend existed for the placebo group to require more blood products than either epsilon-ACA group. CONCLUSIONS Epsilon-ACA produces a reduction in chest tube drainage in patients undergoing primary coronary artery bypass graft surgery. This effect is similar whether the drug is given prior to incision or following anticoagulation. Given the similar hemostatic efficacy and the theoretical potential for thrombotic complications, it may be prudent to administer epsilon-ACA following anticoagulation.