Antiplatelet therapy in acute coronary syndromes without persistent ST-segment elevation.

The treatment of ACS without persistent ST-segment elevation is evolving. Antiplatelet and antithrombin therapy forms the mainstay of medical management. The antiplatelet agents studied can be pharmacologically classified as GP lIb/IIIa receptor antagonists, ADP receptor antagonists, thromboxane inhibitors, and cyclo-oxygenase inhibitors. While aspirin, a cyclo-oxygenase inhibitor, is well entrenched in the treatment (and thus will not be reviewed here), other drugs have been subjects of intense study and large-scale clinical trials in the last decade. In this article we will explore the rationale of using antiplatelet agents, describe the platelet biology and mechanism of action of these drugs, narrate the major phase III trials, and attempt to draw conclusions from the clinical experience. Important trials which have been presented at principal international scientific meetings and which have not yet been published are also cited.