The effect of prophylactic ε-aminocaproic acid on bleeding, transfusions, platelet function and fibrinolysis during coronary artery bypass grafting

Background: Antifibrinolytic medications administered before skin incision decrease bleeding after cardiac surgery. Numerous case reports indicate thrombus formation with administration of epsilon-aminocaproic acid (epsilon-ACA). The purpose of this study was to examine the efficacy of epsilon-ACA administered after heparinization but before cardiopulmonary bypass in reducing bleeding and transfusion requirements after primary coronary artery bypass surgery. Methods: Seventy-four adult patients undergoing primary coronary artery bypass surgery were randomized to receive 125 mg/kg epsilon-ACA followed by an infusion of 12.5 mg.kg(-1).h(-1) or an equivalent volume of saline, Coagulation studies, thromboelastography, and platelet aggregation tests were performed preoperatively, after bypass, and on the first postoperative day. Mediastinal drainage was recorded during the 24 h after surgery, Homologous blood transfusion triggers were predefined and transfusion amounts were recorded. Results: One patient was excluded for surgical bleeding and five patients were excluded for transfusion against predefined criteria, One patient died from a dysrhythmia 2 h postoperatively. Among the remaining 67, the epsilon-ACA group had less mediastinal blood loss during the 24 h after surgery, 529 +/- 241 mi versus 691 +/- 286 mi (mean +/- SD), P < 0.05, despite longer cardiopulmonary bypass times and lower platelet counts, P < 0.05. Platelet aggregation was reduced in both groups following cardiopulmonary bypass but did not differ between groups. Homologous blood transfusion was similar between both groups. Conclusions: Prophylactic administration of epsilon-ACA after heparinization but before cardiopulmonary bypass is of minimal benefit for reducing blood loss postoperatively in patients undergoing primary coronary artery bypass grafting.