797-2 Increased Tissue Factor at Sites of Thrombosis in an Atherosclerotic Animal Model

Atherosclerotic plaque disruption and thrombosis are now recognized as major causes of acute coronary syndromes. Tissue factor may play a central role in linking plaque disruption to thrombus formation. We utilized an atherosclerotic rabbit model of plaque disruption and thrombosis to determine the relationship between luminal surface tissue factor and arterial thrombi.Triggering was attempted in 11 atherosclerotic rabbits and 5 normal rabbits using only intraperitoneal Russell viper venom (a procoagulant) and intravenous histamine (a vasopressor). Thrombi were present in 19 of 34 aortic plaques but none of 11 aortic sections from the normal rabbits. The 34 plaques and 11 normal sections were stained with antibody to tissue factor. While none of the normal specimens had luminal surface tissue factor, it was found on the surface of 17/19 (87%) of plaques with thrombi and 7/15 (45%) of plaques without thrombi (p=0.009).ConclusionPlaques associated with thrombi were significantly more likely to have luminal tissue factor than those without thrombi. These findings support the importance of tissue factor as a link between atherosclerosis and thrombosis