Clopidogrel in Acute Coronary Heart Disease

Platelets play a central role in the pathogenesis of atherothrombosis. Rupture of a coronary artery plaque creates a nidus for platelet aggregation and thrombus formation, which may result in vessel occlusion and subsequent myocardial infarction or death. Despite conventional antiplatelet therapy with aspirin, the risk of recurrent ischemic events remains high. More potent antiplatelet agents have therefore been developed, including the thienopyridines ticlopidine and clopidogrel. By irreversibly blocking the platelet adenosine diphosphate receptor, these drugs powerfully inhibit platelet activation, degranulation, and aggregation. Large clinical trials have demonstrated that combination antiplatelet therapy with clopidogrel and aspirin significantly reduces the risk of adverse cardiac events in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention. The optimal loading dose and length of treatment, however, are yet to be firmly established, and there is a need to clearly identify those patients who will benefit most from additional glycoprotein IIb/IIIa inhibition.