Unstable angina: current concepts of medical management.

Unstable angina describes a clinical syndrome bridging the gap between stable angina and acute myocardial infarction. By definition, patients with angina of new onset, of a crescendo pattern, and with angina at rest are included in this high-risk group. The underlying pathogenetic mechanisms are complex and include initial atherosclerotic plaque rupture, release of vasoactive substances, and intracoronary thrombus formation. The currently established medical approach of the acute phase consists of heparin for anticoagulation and nitrates combined with beta-blockers for the relief of pain. Calcium antagonists are indicated, if anginal symptoms persist. The effect of thrombolytic therapy is still under investigation. Angina refractory to medical treatment and angina at rest are associated with a particularly unfavorable prognosis and prompt early catheterization. The long-term prognosis of the patient is markedly improved by chronic platelet inhibitory treatment with aspirin.