Nafamostat mesilate reduces blood loss during open heart surgery

Background. Nafamostat mesilate (FUT-175) is a protease inhibitor inactivating coagulation, fibrinolysis, and platelet aggregation. A prospective, randomized trial was performed to assess the efficacy of FUT-175 in the reduction of postoperative bleeding tendency. Methods and Results. FUT-175 was infused at a rate of 40 mg/h during cardiopulmonary bypass (CPB) along with 300 IU/kg of heparin in 20 patients undergoing aortocoronary bypass surgery (FUT group). This group was compared with another group of 20 patients undergoing aortocoronary bypass surgery, who were given only heparin (control group). Blood concentrations of FUT-175 and activated clotting time increased after cooling, peaking at 2050±1190 ng/mL and 2136±983 seconds at the lowest temperature and recovered after rewarming to values of 166±118 ng/mL and 510±148 seconds, respectively, at the end of CPB. In the FUT group, platelet counts were significantly higher at the end of CPB than those in the control group (168±10 versus 136±9×10³/mm³, P<.05). In the FUT group, serum concentrations of β-thromboglobulin (307±102 versus 537±391 ng/mL, P<.05), PIC (3.6±1.7 versus 5.8±3.8 μg/mL, P<.05) and FDP (20.2±7.0 versus 41.4±11.9 ng/mL, P<.01) were significantly lower than those in the control group at the end of CPB. However, serum concentrations of TAT, FPA, and FPB β 15-42 showed no significant differences between groups. FUT-175 significantly reduced heparin dosage and 24-hour postoperative blood loss (19 200±3200 versus 29 100±7700 IU, P<.01, and 382±129 versus 576±375 mL, P<.05). Conclusions. FUT-175 inhibits fibrinolysis and preserves platelet counts and function during CPB and reduces blood loss during open heart surgery.