Does acute hyperglycemia add prognostic value to the GRACE score in individuals with non-ST elevation acute coronary syndromes?

Background: It is not known in what extent admission glucose improves risk stratification of the GRACE Score in patients with non-ST-segment elevation acute coronary syndromes (ACS). We tested the hypothesis that admission glucose adds relevant prognostic information to the GRACE Score. Methods: Consecutive patients admitted with ACS had plasma glucose measured at admission and cardiovascular events were defined as death. non-fatal myocardial infarction or non-fatal refractory angina during hospitalization. Results: Among the 148 patients studied, 11.5% developed cardiovascular events. Patients in the forth quartile of admission glucose (>= 175 mg/dl) had a greater incidence of events, compared with those in the first 3 quartiles (22% vs. 8.1%; RR=2.7; 95%Cl 1.1-6.4; P=0.03). Plasma glucose remained a predictor of events, after adjustment for diabetes (P=0.03). After adjustment for the GRACE Score, glucose in the forth quartile lost its predictive value (P=0.29). Plasma glucose added to GRACE did not improve the C-statistics (0.82; 95%Cl 0.75-0.88), as compared with the original Score (0.81; 95%Cl 0.74-0.87). Net reclassification improvement by new score was -0.03 (P=0.86), indicating no useful reclassification. Conclusion: Despite its association with adverse events, admission plasma glucose does not improve GRACE's accuracy to predict in-hospital events in patients with ACS. (C) 2009 Elsevier B.V. All rights reserved.