Unstable Angina and Non–ST Elevation Myocardial Infarction

Abstract

Non-ST elevation acute coronary syndromes are responsible for approximately 1 million admissions to U.S. hospitals and twice as many to European hospitals each year. Thus, they are among the most common serious illnesses in adults, and are associated with an in-hospital mortality of approximately 5%. The most common cause is rupture of an atherosclerotic coronary plaque, resulting in subtotal coronary occlusion. Diagnosis is based on the clinical picture of retrosternal chest pain, aided by electrocardiographic findings of ST segment deviations and biomarker abnormalities (elevation of troponin and natriuretic peptides) and cardiac imaging (myocardial scans showing perfusion defects). Treatment involves antiischemic agents (nitrates and β blockers), antiplatelet drugs (aspirin, P2Y(12), and glycoprotein IIb/IIIa receptor blockers), and anticoagulants (unfractionated and low-molecular-weight heparins). Patients should undergo risk stratification, and those with high-risk factors should undergo coronary arteriography promptly with the intent to carry out coronary revascularization. Those at low risk should continue to receive intensive antiischemic and antithrombotic therapy. At discharge, patients should receive intensive lipid-lowering therapy with high doses of a statin, as tolerated.