Correlation Between the Neutrophil-to-Lymphocyte Ratio and the Severity of Coronary Artery Disease in Patients With Myocardial Infarction

Background Coronary artery disease (CAD) is one of the major causes of death all over the world. Its severity evaluation through the Gensini scoring system is quite a complex process as these score systems require complex investigations and cardiologists. Therefore, this study aimed to determine the predictive capacity of neutrophil-to-lymphocyte ratio (NLR) for the severity of CAD in patients with myocardial infarction. Methods This cross-sectional study was performed on 208 patients with acute myocardial infarction whose coronary angiography was performed in the Department of Cardiology of Benazir Bhutto Hospital (BBH), Rawalpindi, Pakistan during the period of one year from January 2022 to March 2023. The enrollment of patients was made through purposive sampling and established inclusion and exclusion criteria. Ethical approval and informed consent were acquired before the data collection. Data was collected through a self-structured form. Vessel score and Gensini score were applied for the assessment of the severity of CAD. Patients were divided into two groups based on the Gensini score system. Data analysis was carried out in the Statistical Package for the Social Sciences (SPSS) version 25 (Released 2017; IBM Corp., Armonk, New York, United States). Both descriptive and inferential statistics were used to compare the study variables between the patients with non-severe CAD and patients with severe CAD. Pearson's correlation was used to determine the correlation between the NLR and the severity of CAD. A linear regression model was applied to evaluate the predictive capacity of the NLR for the severity of CAD. A p-value less than 0.05 was set as statistically significant. Results Out of 208 patients, 128 (61.53%) patients had non-severe CAD while 80 (38.47%) patients had severe CAD. Significant differences were observed in the Gensini mean scores, NLR values, and in the frequencies of hypertension, diabetes mellitus, dyslipidemia, and history of smoking, with p≤0.05 for all these variables, between the non-severe CAD group and severe CAD group. NLR was significantly correlated with the severity of CAD (p-value=0.001). Pearson's correlation coefficient was 0.71 for NLR with the Gensini scores. The simple linear regression model was valid (the p-value of the F test was <0.000), with beta coefficients of 2.60 (p=0.002) for NLR. The R² value was 0.80 (80%). Conclusions In the current study, a significant percentage of patients had severe CAD. Furthermore, a positive and significant association was noted between the NLR with the severity of CAD. This present study suggests that NLR is a reliable predictor of CAD severity; therefore, it could be used for risk stratification of cardiac patients with CAD.