High-Dose ε-Aminocaproic Acid Versus Aprotinin: Antifibrinolytic Efficacy in First-Time Coronary Operations

Background. The antifibrinolytic efficacy of a high-dose regimen of ε-aminocaproic acid (ε-ACA) was compared with aprotinin in first-time coronary operations. Methods. In a prospective, double-blinded, randomized study, 20 patients received high-dose ε-ACA (10 g both as a loading and cardiopulmonary bypass priming dose, 2.5 g/h until 4 hours after protamine), and another 20 patients received aprotinin (2 × 106 KIU [280 mg] for loading and priming, 0.5 × 106 KIU/h [70 mg/h]). Ten untreated patients served as controls. Results. Both agents reduced postoperative levels of thrombin/antithrombin III complexes, image-dimers, fibrin degradation products, free plasma hemoglobin (ε-ACA versus aprotinin, p = not significant; p < 0.05 versus controls), and amount of retransfused autologous blood (p < 0.001). ε-ACA increased, aprotinin suppressed antiplasmin–plasmin complex generation (ε-ACA versus controls, p < 0.02; ε-ACA versus AP, p < 0.0001). For 4 hours after discontinuation, more chest drainage occurred with ε-ACA than aprotinin (137 ± 90 mL versus 62 ± 29 mL; means ± standard deviation; p < 0.02). Cumulative 12-hour drainage was similar for aprotinin (391 ± 220 mL) and ε-ACA (582 ± 274 mL), but higher without inhibitor (1,091 ± 541 mL; p < 0.001 versus drugs). Postoperatively, aprotinin was associated with the lowest autologous retransfusion incidence and highest hematocrits (p < 0.01 versus ε-ACA). Homologous transfusion exposures did not differ. Conclusions. In first-time coronary operations, higher postoperative hematocrit and less shed blood retransfusion constitute only subtle advantages of aprotinin over high-dose ε-ACA.