EFFECTS OF MINIMAL-DOSE APROTININ ON CORONARY-ARTERY BYPASS-GRAFTING

Objective: To evaluate the effects of minimal-dose aprotinin in patien ts undergoing coronary artery bypass grafting, we conducted a prospect ive randomized study. Methods: A total of 167 patients were randomized to receive no aprotinin treatment (control, n = 57), minimal-dose apr otinin (1.0 x 10(6) KIU; n = 55), or low-dose aprotinin (2.7 +/- 0.5 x 10(6) KIU; n = 55), Blood loss and transfusion requirements, paramete rs of clotting and fibrinolysis, renal function, and early graft paten cy rates were assessed. Results: Postoperative blood loss and transfus ion requirements were significantly (p = 0.01) lower in both the minim al-dose and low-dose groups than in the control group. The increase in D-dimer level after cardiopulmonary bypass was significantly (p < 0.0 5) less marked in the low-dose group than in the control group. The al pha(2)-plasmin inhibitor and plasminogen activator inhibitor-1 levels were significantly (p < 0.05) greater in the minimal-dose and low-dose groups than in the control group after bypass, suggesting the prevent ion of fibrinolysis by both aprotinin doses. No statistically signific ant differences in postoperative renal function and early vein graft p atency rates were noted (control group, 93.8%; minimal-dose group, 98. 5%; low-dose group, 92.3%; p = 0.25). Conclusions: Aprotinin was not a ssociated with a significant increase in the prevalence of renal dysfu nction or early vein graft occlusion. Minimal-dose aprotinin inhibited enhanced fibrinolytic activity and reduced blood loss and transfusion requirements after bypass equivalently to low-dose aprotinin. The dos e of 1 x 10(6) KIU added to the pump prime may be acceptably effective in reducing blood loss in patients undergoing primary coronary operat ions.