Thrombin Generation in Hemorrhage Control and Vascular Occlusion

Abstract

The outcome of a blood clotting event is either desirable or undesirable. All of these events involve the generation of thrombin from plasma components, the participation of platelets, and the local conditions associated with the vascular environment. Good hemostatic clots are largely relegated to the extravascular environment, whereas pathological occlusive clots are associated with the presentation of TF within the vasculature. Although reactions in both of these environments involve platelet function, the high shear present in arterial environments requires extensive participation of platelets, and both pathologies may involve systemic inflammatory-coagulation syndromes.93 The varying effectiveness of the nature and intensity of anticoagulant treatment for venous and arterial thrombosis is a consequence of these biochemical, cell biological, and biomechanical phenomena. Data for the contributions of the vascular anticoagulation systems, ie, thrombomodulin, EPCR, TFPI, and heparan sulfate proteoglycan, are not qualitatively or quantitatively established within the vasculature. The development of data regarding the concentrations of these anticoagulants in different vascular beds is essential to the meaningful evaluation of the dynamics that influence the susceptibility of an occlusive clot to form in different sites in the vascular anatomy. © 2011 American Heart Association, Inc.