Inhibition of the tissue factor coagulation pathway.

It is widely accepted that blood coagulation in vivo is initiated during normal hemostasis, as well as during intravascular thrombus formation, when the cell-surface protein, tissue factor, is exposed to the blood as a consequence of vascular injury. In addition to its essential role in hemostasis, tissue factor may be also implicated in several pathophysiological processes, such as intracellular signaling, cell proliferation, and inflammation. For these reasons, the tissue factor:factor VIIa complex has been the subject of intense research focus. Many experimental studies have demonstrated that inhibition of tissue factor:factor VIIa procoagulant activity are powerful inhibitors of in vivo thrombosis and that this approach usually results in less pronounced bleeding tendency, as compared to other "more classical" antithrombotic interventions. Alternative approaches may be represented by transfecting the arterial wall with natural inhibitors of tissue factor:factor VIIa complex, such as tissue factor pathway inhibitor, which may result in complete inhibition of local thrombosis without incurring in potentially harmful systemic effects. Additional studies are warranted to determine the efficacy and safety of such approaches in patients.