 Platelets, platelet products, and thrombosis play important and proximate causal roles in the occurrence of acute occlusive vascular events such as MI and ischemic stroke. The disruption of platelet and fibrin rich atherosclerotic plaques may lead to enhanced platelet deposition, and ultimately the formation of a thrombus that can precipitate an acute clinical event. The following observations are compatible with the importance of platelet thrombus formation in acute ischemic syndromes: 