Keele Research Repository

Background: The Global Registry of Acute Coronary Events (GRACE) score was developed to evaluate risk in patients with acute coronary syndrome with or without ST-segment elevation. Little is known about its performance at predicting in-hospital mortality for ethnic minority patients. Methods and Results: We identified 326,160 admissions with non-ST-segment elevation myocardial infarction (NSTEMI) in the Myocardial Infarction National Audit Project (MINAP), 2010-2017, including White (n = 299,184) and ethnic minorities (excluding White minorities) (n=26,976). We calculated the GRACE score for in-hospital mortality and assessed ethnic group baseline characteristics by low, intermediate and high risk. Performance of the GRACE risk score was estimated by discrimination (area under the receiver operating characteristic curve [AUC]) and calibration (calibration plots). Ethnic minorities presented younger and had increased prevalence of cardiometabolic risk factors in all GRACE risk groups. The GRACE risk score for White (AUC 0.87, 95% confidence interval [CI] 0.86-0.87) and ethnic minority (AUC 0.87, 95% CI 0.86-0.88) patients had good discrimination. However, whilst the GRACE risk model was well calibrated in White patients (expected to observed (E:O) in-hospital death rate ratio 0.99; slope 1.00), it overestimated risk in ethnic minority patients (E:O ratio 1.29; slope: 0.94). Conclusion: The GRACE risk score provided good discrimination overall for in-hospital mortality, but was not well calibrated and overestimated risk for ethnic minorities with NSTEMI.