Risk Stratification in Patients with Unstable Angina and Non-ST-elevation Myocardial Infarction.
Risk stratification in acute coronary syndromes is important both for prognosis and for treatment. Consistently, using any of a variety of clinical predictors of risk, patients at highest risk for poor outcomes derive the greatest benefit from aggressive therapy with early coronary angiography, glycoprotein IIb/IIIa antagonists, or low molecular weight heparins. By contrast, patients at low risk may be managed conservatively without long-term impact on their risk of death or myocardial infarction. Several clinical and laboratory parameters have been identified as independent, powerful predictors of poor outcome, helping to distinguish high-risk from low-risk patients. Although not a substitute for astute clinical judgment, risk prediction scores may help clinicians to synthesize the relevant clinical data at presentation into an overall assessment of risk, allowing for cost-effective utilization of therapies that add significant expense and morbidity. With the ever-expanding range of pharmacologic and interventional therapies that impact the treatment of patients with unstable angina and non-ST-elevation myocardial infarction (NSTEMI), risk stratification will become increasingly important in targeting therapies to those who are likely to achieve the most benefit. In this review, we first consider the identifiable components of risk in patients presenting with unstable angina or NSTEMI and then evaluate the emerging information regarding differential response to treatment based on the presence of these risk factors.