Thrombin Generation Assay: Are We Ready for Prime Time?

The prothrombin time (PT)3 and partial thromboplastin time (PTT) are useful assays for evaluation of coagulation factor levels and for monitoring anticoagulant therapy with warfarin and heparin, but they are of less value for predicting risk of thrombosis or bleeding in patients with acquired hemostatic defects. As new anticoagulant drugs become available and pathophysiologic mechanisms of abnormal hemostasis are unveiled, it is clear that new laboratory tests are needed to support drug monitoring, establish diagnosis, and develop therapeutic strategies. Over the past several years, a number of existing tests have been improved to offer additional information not available from PT/PTT, which include thromboelastography to evaluate fibrinolysis and target antifibrinolysis, thrombin generation assays (TGAs) for predicting bleeding and thrombotic risk, and anti-Xa and direct thrombin inhibitor assays to monitor direct oral anticoagulants. First-generation TGAs were performed in whole blood and plasma, but these were cumbersome and …