Identificación de variables predictivas de riesgo en la evaluación incial de la angina inestable.

Abstract

Background and purpose: Patients with suspected non-ST-segment elevation acute coronary syndromes (NSTEACS) constitute a heterogeneous population with variable outcomes. Risk stratification in this population is dificult due to the complexity in patient risk profile. We conducted this study to characterize the value of clinical and electrocardiographical variables for risk stratification in an unselected population of consecutive patients with NSTEACS on admission. Methods: We prospectively included 415 consecutive patients admitted with non-ST elevation acute coronary syndrome (65±11 y.; 27% female) between November 1997 and July 1998 and looked for the combined end-point of cardiac death or myocardial infarction during hospitalization and at long-term (mean follow-up 50 months). Baseline clinical and electrocardiographical data as well as serum concentrations of CPK-MB, creatinine and fibrinogen were prospectively recorded. The Student t-test was applied for comparisons between continuous variables with normal distribution, the chi-squared test for categorical data, Kaplan-Meier curves (log-rank test) for survival analysis and the Cox regression model to investigate the effect of several variables upon the follow-up. Results: In-hospital cardiovascular mortality was 2.7% and the rate for the outcome of either cardiovascular death or nonfatal myocardial infarction was 4.6%. Independent predictors of in-hospital death or nonfatal myocardial infarction were age (?65 years), ST segment depression and elevation of fibrinogen levels. The incidence of cardiovascular mortality or nonfatal myocardial infarction at long term was of 17.3%. Significant multivariate predictors of long term mortality or nonfatal myocardial infarction were age (65 years), ST segment depression, arterial hypertension, stroke, diabetes mellitus, Killip class ? II at admission, renal dysfunction and elevation of fibrinogen levels. Conclusions: 1. The in-hospital prognosis of NSTEACS is good. However, patients discharged from hospital after clinical stabilization present an important number of ischemic complications during the following 3 months, similar to that presented by all patients during the acute phase. 2. Simple clinical, electrocardiographical and biochemical data obtained at hospital admission allow an accurate risk stratification of patients with NSTEACS.