摘要Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospective and observational study,we recruited 500 patients with ACS.For all the eligible patients,demographic details were collected,and laboratory parameters were evaluated.The CAD severity was evaluated in terms of the number of involved vessels.The NLR was calculated based on neutrophils and lymphocytes and the correlation of various risk factors and severity and outcome of CAD was performed.Results:77.2%of Patients was male,and 52%of the patients aged between 55-70 years.Based on the type of ACS,396 out of 500 patients had ST-elevation myocardial infarction.An ascending trend in the white blood cell levels and NLR value was noted as the severity of the ACS increased and the highest white blood cell levels and NLR was noted among class Ⅳ patients.The mean NLR value among the non-survivors were higher compared to the survivors(9.52±5.72 vs.4.76±2.36;P<0.01).Receiver operating curve showed that the cut-off NLR value was 5.76 with a sensitivity of 75.0%and a specificity of 77.3%.Conclusions:The NLR can be used as an independent prognostic marker in ACS.An elevated NLR value serves as a reliable predictor for short-term complications,notably in-hospital mortality.