Antithrombotic therapy for acute coronary syndromes

Abstract

Objectives: To review the role of antithrombotic therapy for treatment of acute coronary syndromes (ACS) in the hospital setting.

Data sources: 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.

Study selection: Recent systematic English-language review articles and reports of controlled randomized clinical trials were screened for inclusion.

Data synthesis: 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.

Conclusion: 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.