Nafamostat mesilate administration during cardiopulmonary bypass decreases postoperative bleeding after cardiac surgery.

The hemostatic effect of nafamostat mesilate (FUT-175) was evaluated in patients undergoing cardiopulmonary bypass (CPB) surgery. Thirty patients undergoing aortocoronary bypass grafting were divided into two groups. In the control group, anticoagulation was achieved with an initial dose of heparin (3 mg/kg). In the FUT-175-treated group, in addition to the ordinary treatment with heparin, FUT-175 was infused continuously into the circuit throughout the procedure at a rate of 100 mg/hr. Thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA), and fibrin degradation products (FDP-D) dimer increased in both groups as CPB proceeded. In the FUT-175-treated group, these parameters remained lower and decreased more rapidly after the end of CPB. Alpha 2 plasmin inhibitor/plasmin complex (PIC) increased progressively during CPB in the control group; no such significant increases were seen in the FUT-175-treated group. Postoperative blood loss was significantly lower in the FUT-175-treated group than in the control group. It was concluded that FUT-175 reduces postoperative blood loss by inhibiting both coagulation and fibrinolysis during CPB.