Prognostic Value of Continuous ST‐Segment Monitoring in Patients with Non‐ST‐Segment Elevation Acute Coronary Syndromes

Abstract

Background: Patients with non‐ST‐segment elevation acute coronary syndromes constitute a heterogeneous group concerning prognosis. The 12‐lead ECG at rest is recommended for early risk stratification but is unable to reflect the dynamic nature of myocardial ischemia and coronary thrombosis. This study investigated whether continuous ST‐segment monitoring provides early prognostic information in such patients. Methods: We prospectively studied 183 patients admitted due to chest pain at rest suggestive of an acute coronary syndrome. ST‐segment monitoring was performed continuously for 24 hours from admission. Cardiac‐specific troponin I levels were determined on admission and every 6 hours for the first 24 hours. The endpoint was defined as death or nonfatal myocardial infarction, whichever occurred first by 30 days follow‐up. Results: ST episodes, defined as transient ST deviations of at least 0.1 mV, were detected in 50 patients 27.3%) and associated with worse 30‐day outcome: 22.0% endpoint rate compared to 6.8% for patients without ST episodes (P = 0.003). In a multivariate analysis, the presence of ST episodes hazard ratio, 3.07; 95% Cl, 1.26 to 7.46; P = 0.014) and peak troponin I levels > 0.2 μg/L (hazard ratio, 2.65; 95% Cl, 1.01 to 6.95; P = 0.048) were independent predictors of prognosis. The combination of ST‐segment monitoring and peak troponin I identified patients at low (2.5%, n = 79), intermediate (14.5%, n = 76), and high (25.0%, n = 28) risk for the 30‐day endpoint. Conclusions: In patients with non‐ST‐segment elevation acute coronary syndromes, continuous ST‐segment monitoring provides on‐line early prognostic information, in addition to troponin I levels. A.N.E. 2002;7(1):29–39

Keywords

• ST‐segment monitoring
• troponin
• acute coronary syndrome
• prognosis