On the basis of clinical characteristics and laboratory markers on admission, patients can generally be categorized as at low risk, intermediate risk, or high risk (Fig. 5). Patients at low or intermediate risk (i.e., those without pain at the time of evaluation, those who have an unchanged or normal electrocardiogram, and those whose condition is hemodynamically stable) should be treated with aspirin and assessed further. If they have been asymptomatic for more than 24 hours, they may undergo evaluation on an outpatient basis if the evaluation can be completed within 72 hours after discharge? High-risk patients are those who have had angina at rest, prolonged angina, or persistent angina with dynamic ST-segment changes or hemodynamic instability, and they urgently require simultaneous evaluation and treatment. Medical therapy should be adjusted rapidly to relieve manifestations of ischemia and should include antiplatelet therapy (aspirin, or ticlopidine or clopidogrel if aspirin is contraindicated), antithrombotic therapy (unfractionated heparin or low-molecular-weight heparin), beta- blockers, nitrates, and possibly calcium-channel blockers. Early administration of glycoprotein IIb/IIIa inhibitors may be particularly important, especially in high-risk patients with positive troponin tests or those in whom implantation of coronary stents is anticipated. The safety and efficacy of combined, intensive antiplatelet therapies (glycoprotein IIb/IIIa inhibitors) and antithrombotic therapies (low-molecular-weight heparins) have yet to be clarified. The condition of the vast majority of patients stabilizes rapidly with aggressive medical management, and such patients can then undergo tests to assess their level of risk. If manifestations of ischemia recur, either spontaneously or during testing, patients should undergo coronary angiography and revascularization. Patients whose condition remains stable and who are considered to be at low risk may be suitable for continued medical management. Use of early, reliable risk-stratification process may permit the appropriate and economical allocation of medical resources and the optimal outcomes for patients.
