Clinical scores and patient risk stratification in non-ST elevation acute coronary syndrome

Abstract

Risk stratification of patients with unstable angina or non-ST-segment elevation myocardial infarction (UA/NSTEMI) is problematic given the heterogeneous presentation of the condition. This study was undertaken to compare, in UA/NSTEMI patients, the prognostic value of two clinical risk scores (RS) (i.e. Thrombolysis in Myocardial Infarction (TIMI) and physician's risk assessment (PRA)) and to assess whether serum biomarkers can increase the prognostic accuracy of these RS. We prospectively assessed 610 consecutive UA/NSTEMI patients, 217 (36%) UA and 393 (64%) NSTEMI. In all patients RS, high sensitivity C-reactive protein, CD40 ligand, IL6, IL10, IL18, E-selectin, P-selectin, white blood cell count, neopterin, myeloperoxidase, fibrinogen and NT proBNP were assessed at study entry. The primary study endpoint was death and non-fatal MI at 30 and 360 days of follow-up. At 1 year, 54 patients (8.9%) had reached the primary study endpoint (26 suffered a cardiac death (4.3%) and 34 (5.6%) a non-fatal MI). For both RS, the study endpoint occurred more commonly in patients at a "higher risk" compared to those classified as being at a "lower risk". Moreover, TIMI and PRA RS had similar discriminatory accuracy. TIMI RS, however, was a better predictor of events than PRA at both 30- and 360-day follow-up. The inflammatory biomarkers assessed in the study did not improve significantly the predictive value of RS. Our study suggests both that TIMI RS is a better marker of risk than PRA RS and inflammatory biomarkers do not increase the predictive value of these clinical risk scores.