Unstable angina (UA) comprises a broad spectrum of ischemic heart disease & is associated with varying levels of risk for unfavorable outcomes including myocardial infarction & death. This report is based on 3 systematic reviews of published studies through 1998. The first review concerned the value of the electrocardiogram, physical exam., & clinical history in predicting outcomes for patients with UA. The second review examined the ability of troponin to predict outcomes in patients with proven or suspected UA. The third review examined the efficacy of chest pain units & emergency department protocols in patients who have suspected UA or myocardial infarction. Charts & tables.