Antithrombotic Therapy for Acute Coronary Syndromes

Abstract

To review the role of antithrombotic therapy for treatment of acute coronary syndromes (ACS) in the hospital setting. Recent (1995-2003) published scientific literature, as identified by the authors through Medline searches, using the terms acute coronary syndromes, antithrombotic, antiplatelet, clinical trials, and reviews on treatment. Recent systematic English-language review articles and reports of controlled randomized clinical trials were screened for inclusion. For the patient with ST-segment elevation (STE) ACS, nonenteric-coated aspirin should be initiated immediately, if possible before arrival at the emergency department. In-hospital treatment is aimed at rapidly re-establishing coronary patency by means of percutaneous coronary intervention (PCI) or thrombolysis, preventing cardiac complications, and improving survival. Patients undergoing primary PCI should receive a glycoprotein IIb/IIIa receptor inhibitor, unfractionated heparin (UFH), and clopidogrel (Plavix--Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership) if bypass surgery is not urgently indicated; those undergoing thrombolysis should receive UFH. For the patient with non-ST-segment elevation (NSTE) ACS, beta-blockers, nitrates (also indicated for STE myocardial infarction), antiplatelet agents, and antithrombin therapy (UFH or low-molecular-weight heparin) are provided in standard care. Aspirin should be commenced immediately and continued indefinitely; in addition, clopidogrel is recommended for patients who are medically managed and those undergoing PCI. Glycoprotein IIb/IIIa receptor inhibitors (tirofiban [Aggrastat--Guilford Pharmaceuticals], eptifibatide [Integrilin--Millennium Pharmaceuticals], and abciximab [ReoPro--Lilly]) are of benefit in reducing ischemic complications in patients undergoing PCI. Early reperfusion with thrombolytics or primary PCI is required in patients presenting with STE ACS. Early invasive management is recommended for high-risk patients with NSTE ACS; for lower-risk patients, either early invasive or early conservative therapy is recommended.