Preservation of collagen-induced whole blood platelet aggregation by tranexamic acid therapy in primary cardiac valve surgery

Haemostatic disorder is one of the most common complications following card iac surgery with cardiopulmonary bypass (CPB). Tranexamic acid reduces bloo d loss and allogeneic blood transfusion requirement in cardiac surgery. It had been thought that tranexamic acid inhibited fibrinolysis alone followin g CPB. In the present study, the haemostatic effects of tranexamic acid (20 mg/kg body weight bolus after induction of anaesthesia followed by continuous inf usion at 2 mg/kg/h), including fibrinolysis and platelet function, were inv estigated in 22 patients (tranexamic acid group n = 12; control group n = 1 0) undergoing prim-cry cardiac valve surgery. Fibrinolysis following CPB was reduced significantly in the tranexamic acid group. Following protamine administration, the reduction of collagen-induc ed whole blood platelet aggregation was mitigated significantly in the tran examic acid group compared with the control group (36% reduction in the tra nexamic acid group vs 58% in the control group; p = 0.011). although platel et counts did not differ between the two groups. In conclusion, tranexamic acid not only inhibits fibrinolysis directly, but also may preserve platelet function following CPB.