Association between Neutrophil-to-Lymphocyte Ratio and the Systemic Inflammatory Immunologic Index and the Angiographic SYNTAX Score and the TIMI Flow Grade in Acute STEMI: A Cohort Study.

Background: In patients with ST-segment-elevation myocardial infarction (STEMI), it is essential to determine the complexity of coronary lesions on presentation and predict the risk of no-reflow after primary percutaneous coronary intervention (pPCI). Given that inflammation plays an important role in the pathogenesis of atherosclerosis, using inflammatory indices might be helpful in this setting. Methods: This prospective cohort study recruited 200 consecutive patients with STEMI who underwent pPCI. The presentation neutrophil-to-lymphocyte-ratio (NLR) and the systemic inflammatory immunologic index (SII), calculated using the formula platelets × neutrophils/lymphocytes, were recorded. Study outcomes included the SYNTAX score and the TIMI flow grade before and after pPCI. The associations between the NLR and the SII and the study outcomes were investigated using univariate and multivariate logistic regression analyses. Results: Among 200 patients at a mean age of 59.85±11.23 years, 160 (80.0%) were male and 40 (20.0%) were female. The NLR and SII values were not statistically different between the 3 SYNTAX subgroups. While the mean NLR and SII values were similar between the patients with preprocedural TIMI flow grades 0/1 and 2/3, the mean NLR and SII were significantly lower in the group with a postprocedural TIMI flow grade 3. After adjustments for age and sex, the NLR and the SII were independent predictors of postprocedural no-reflow. Conclusion: In patients with STEMI, the presentation NLR and SII are useful for predicting the risk of no-reflow after pPCI. However, the NLR and the SII are not predictors of the SYNTAX score and the preprocedural TIMI flow grade.