Neutrophil-to-lymphocyte ratio (NLR) in the acute coronary syndrome patients presenting in the pre and post-COVID-19 era

Background: The inflammatory pathways play a key role in the pathogenesis of acute coronary syndrome and the severe forms of COVID-19 disease. Thus inflammation may play an interrelation between these two critical situations. Materials and Methods: In this study, the records of the patients of ACS admitted to the coronary care unit, were analyzed retrospectively. The two groups had 200 patients each. The group-A was randomly taken from the pre-COVID period of July to December 2019 while group-B patients were taken from the COVID/post-COVID period of July 2021 to December 2021. The two groups were compared for the severity of inflammation, through the leukocyte ratios of NLR and d-NLR. Results: The neutrophil percentage as well as the ANC were significantly higher, while the percentage of lymphocytes and ALC were significantly lower in the group-B patients compared to the group-A patients (p ˂ 0.05). The NLR (mean ±SD) was significantly higher in group-B compared to group-A patients (6.38±4.84 vs 5.34±4.37, p ˂ 0.05), while the d-NLR showed no significant difference. The NLR values were significantly higher in group-B compared to group-A, for patients of age ˂ 45 years (7.13±5.8 vs 4.3±2.73, p ˂ 0.05) and for patients presenting with ST-Elevation ACS (7.17±5.2 vs 5.54±4.22, p ˂ 0.005). Conclusion: The degree of inflammation as indirectly measured by the ratios of NLR and d-NLR, was found to be higher in the ACS patients presenting in the COVID/post-COVID era when compared to those in the pre-COVID era.