Neutrophil count improves the GRACE risk score prediction of clinical outcomes in patients with ST-elevation myocardial infarction

ObjectiveBoth the Global Registry of Acute Coronary Events (GRACE) risk score and neutrophil count could predict clinical outcomes in patients with acute coronary syndromes. However, the ability of them to identify high risk patients leaves room for improvement. The purpose of the present study was to evaluate whether the combination of them could have a better performance in predicting clinical outcomes in patients with ST-elevation myocardial infarction (STEMI).MethodsA total of 1287 consecutive STEMI patients were recruited at two centers in China. Neutrophil count was measured and the GRACE risk score was calculated.ResultsDuring a median period of 37 months (IQR, 29-47), 135 (10.9%) patients had major adverse cardiovascular events (MACE), including 116 all-cause death. Neutrophil count and the GRACE risk score were higher in patients with MACE. Both neutrophil count and the GRACE score were significant and independent predictors for MACE [HR: 1.260 (1.203-1.319), P < 0.001; HR: 1.007 (1.002-1.011), P < 0.001; respectively). Combination of them increased the area under the ROC (0.698 vs. 0.796, P < 0.001). The addition of neutrophil count to GRACE model enhanced net reclassification improvement (0.637, P = 0.020) and integrated discrimination improvement (0.180, P < 0.001), suggesting effective discrimination and reclassification.ConclusionBoth neutrophil count and the GRACE risk score are independent predictors for MACE in patients with STEMI. A combination of them could derive a more accurate prediction for clinical outcomes in these patients.