Neutrophil-to-Lymphocyte Ratio Is Not Associated with Severity of Coronary Artery Disease and Is Not Correlated with Vitamin D Level in Patients with a History of an Acute Coronary Syndrome

SIMPLE SUMMARY: Coronary artery disease (CAD), the leading cause of death worldwide, is caused by atherosclerosis. Atherosclerosis has an inflammatory component, which can be measured with the neutrophil-to-lymphocyte ratio (NLR). Vitamin D has anti-inflammatory and anti-atherogenic properties that affect many mechanisms involved in CAD. In this study, we investigated the association between NLR, vitamin D levels, and the severity of CAD in a group of patients who had a myocardial infarction (MI) in the past. Our results show that patients with acute coronary syndrome had a higher NLR compared to those with stable CAD. No associations were observed between NLR and the severity of CAD. We found no correlation between vitamin D levels and NLR. NLR could be used as a prognostic marker of consecutive MI in patients with CAD and previous MI. ABSTRACT: Coronary artery disease (CAD), the leading cause of death worldwide, has an underlying cause in atherosclerosis. The activity of this inflammatory process can be measured with neutrophil-to-lymphocyte ratio (NLR). The anti-inflammatory and anti-atherogenic properties of vitamin D affect many mechanisms involved in CAD. In this study, we investigated the association between NLR, vitamin D concentration, and severity of CAD in a group of patients with a history of myocardial infarction (MI). NLR was higher in patients with acute coronary syndrome (ACS) in comparison to those with stable CAD (median: 2.8, range: 0.96–24.3 vs. median: 2.3, range: 0.03–31.6; p < 0.05). No associations between NLR and severity of CAD (p = 0.14) in the cohort and in the subgroups with stable CAD (p = 0.40) and ACS (p = 0.34) were observed. We found no correlation between vitamin D level and NLR neither in the whole study group (p = 0.29) nor in subgroups of patients with stable CAD (p = 0.84) and ACS (p = 0.30). NLR could be used as prognostic biomarker of consecutive MI in patients with CAD and a history of MI.