Association between Neutrophil to Lymphocyte Ratio and the Extent of Coronary Artery Disease in Patients with STEMI Versus Patients With Stable Angina Undergoing PCI: An Idea for Investigation of Other Inflammatory Diseases

Background: Inflammation plays an important role in the pathogenesis of diseases such as atherosclerosis and other inflammatory disorders. The inflammatory markers impose a considerable cost on the health system. Recently, neutrophil to lymphocyte ratio (NLR) has been shown to be involved in the prediction of coronary artery disease (CAD). Objectives: This study was conducted to clarify the potential relationship between NLR and the inflammatory extent of CAD. Materials and Methods: Patients with ST-elevation myocardial infarction (STEMI) or stable angina who underwent primary or elective percutaneous coronary intervention (PCI), respectively, were included in this cross-sectional study. Patients with hematologic disorders, recent or active infectious or inflammatory diseases, history of malignancy, and history of treatment with immunosuppressive drugs were excluded from the study. Gensini and SYNTAX scores were calculated for each patient as an indicator of the extent of CAD. Demographic and clinical characteristics were obtained through a questionnaire and NLR was calculated using laboratory results. Results: A total of 446 patients (223 patients in each group) fulfilled the inclusion criteria. NLR had a significant relationship with Gensini score in both stable angina and STEMI patients. Gensini and SYNTAX scores correlated significantly with NLR; however, the correlation was weaker for SYNTAX score. After adjustment for confounding factors, including age and hypercholesterolemia, only one trend remained for the Gensini scores. Conclusion: NLR showed a stronger correlation with Gensini score than SYNTAX score. Our findings are in accordance with previous studies, which show that NLR has a relationship with the extent of CAD. Further studies are required for reaching a definite conclusion. The idea of this study may be useful for the investigation of other inflammatory diseases.