Prognostic value of clinical variables at presentation in patients with non-ST-segment elevation acute coronary syndromes: results of the Proyecto de Estudio del Pronóstico de la Angina (PEPA).

Patients with suspected non-ST-segment elevation acute coronary syndromes (NSTEACS) constitute a heterogeneous population with variable outcomes. Risk stratification in this population of patients is difficult due to the complexity in patient risk profile. We conducted this study to characterize the value of clinical and electrocardiographic variables for risk stratification in an unselected population of consecutive patients with NSTEACS on admission. Thirty-five clinical and electrocardiographic variables at presentation in the emergency room of 18 hospitals were prospectively analyzed in 4,115 patients with NSTEACS and related with the outcomes at 90 days. We also developed a risk score using the variables found to be independent predictors of ischemic events to facilitate risk stratification. Cardiovascular mortality was 4.3% and the rate for the outcome of either cardiovascular death or nonfatal myocardial infarction was 6.9%. The only independent predictors of mortality were age, diabetes, peripheral vascular disease, postinfarction angina, Killip class > or = 2, ST-segment depression, and elevation of cardiac markers. A risk profile using the variables found to be independent predictors of events was calculated for cardiovascular mortality and for the combination of either death or nonfatal myocardial infarction. Event rates increased significantly in all subgroups of patients based on the number of independent risk factors as the risk score increased. Using these factors, 90-day mortality ranged from as low as 0.4% in patients with no risk factors to 21.1% for those with more than 4 risk factors. In conclusion, simple clinical and electrocardiographic data obtained at hospital admission allow an accurate risk stratification of patients with NSTEACS. In the PEPA registry, simple variables easy to obtain at admission appear to be a valuable tool in discerning between patients at very low and very high risk according to the cluster of factors for each patient. The risk score developed was obtained from an unselected population, representative of the whole spectrum of patients with NSTEACS, allowing identification of patients at different risks for adverse outcomes, and, therefore, permitting optimization of therapy.