INTRODUCTION
Heparin is a widely used anticoagulant that inhibits thrombin and factor Xa via antithrombin III. Bivalirudin is a direct thrombin inhibitor and does not inhibit factor Xa. It inhibits both circulating and clot-bound thrombin. In order to better understand the mechanisms of action of these anticoagulants, we studied their effects on the viscoelastic coagulation tests: Rotational thromboelastometry, Thromboelastography and Sonoclot. Here, we provide only representative signatures obtained on viscoelastic coagulation testing of blood samples of patients undergoing open heart surgery and anticoagulated with either heparin or bivalirudin.
