One of the most important developments in the field of cardiovascular medicine over the last two decades has been recognition of the key role played by arterial thrombosis in the pathogenesis of acute coronary syndromes, ischemic complications of percutane ous coronary revascularization, and coronary and peripheral atherosclerosis. The phar macologic armamentarium directed against vascular thrombosis has thus expanded substantially during that time, with development of new fibrinolytic agents, low-molecu lar-weight heparins, direct thrombin inhibitors, antagonists to platelet activation, and...