A combination of the neutrophil-to-lymphocyte ratio and the GRACE risk score better predicts PCI outcomes in Chinese Han patients with acute coronary syndrome

OBJECTIVE The aims of this study are to evaluate the relationship between the Global Registry of Acute Coronary Events (GRACE) risk score and neutrophil to lymphocyte ratio (NLR) and to determine whether a combination of these factors improves the predictive value for long-term cardiovascular events in Chinese Han patients with acute coronary syndrome (ACS). METHODS In this prospective, observational, and single-center study, NLRs (neutrophil count/lymphocyte count) were calculated from the complete blood count of 1050 patients with ACS, whereas GRACE risk scores were calculated from patients' clinical parameters obtained on arrival at our hospital. Cox proportional hazards models were used to determine independent factors associated with cardiovascular events. RESULTS NLR was positively correlated with the GRACE risk score (r=0.66, p<0.001), and both the GRACE risk score (HR: 1.01; 95% CI: 1.01-1.02; p<0.001) and NLR (HR: 1.09; 95% CI: 1.06-1.14; p<0.001) independently predicted cardiovascular events. The area under the receiver operating characteristic (ROC) curve was 0.69 (95% CI: 0.64-0.72; p<0.001) when the GRACE score was calculated alone; however, it significantly increased (p<0.001) to 0.77 (95% CI: 0.74-0.80; p<0.001) when the GRACE score was combined with NLR. CONCLUSION This study shows for the first time that NLR is positively associated with the GRACE risk score and demonstrates that a combination of these two factors may improve the predictive value for cardiovascular events in Chinese Han patients with ACS.