Antiplatelet therapy in coronary artery disease: review and update of efficacy studies.

The mechanisms of action of currently available and newer antiplatelet agents and evidence of the efficacy of antiplatelet agents for primary and secondary prevention of coronary artery disease are reviewed. Available data do not support the widespread use of aspirin for primary prevention of cardiovascular disease. Patients over the age of 50 years with at least one additional risk factor for coronary artery disease may benefit, although possibly at an increased risk of hemorrhagic stroke. Aspirin is recommended for secondary prevention of vascular disease in patients with stable or unstable angina, clinical or laboratory evidence of coronary artery disease, history of myocardial infarction, or history of stroke or transient ischemic attack. There are no data supporting a role for dipyridamole for primary or secondary prevention of ischemic heart disease. Abciximab has been shown to reduce the risk of cardiovascular complications at 30 days after percutaneous transluminal coronary angioplasty in patients with refractory unstable angina. Studies with other glycoprotein IIb/IIIa-receptor antagonists, including eptifibatide, tirofiban, and lamifiban, have yielded promising results. Ticlopidine may be used for secondary prevention of cardiovascular disease in patients with unstable angina who are allergic to or intolerant of aspirin. Clopidogrel has been shown to be safe and effective for secondary prevention of vascular events. Aspirin has a role in secondary prevention of coronary artery disease; among patients who are allergic to or intolerant of aspirin, ticlopidine has a role in patients with unstable angina and clopidogrel has a potential role in patients with ischemic heart or vascular disease.