Background: Previous studies have demonstrated that inflammation, neurohormonal process and cardiovascular risk factors are associated with the development of coronary artery ectasia (CAE). However, the underlying mechanisms responsible for ectasia formation are not fully understood. The neutrophil to lymphocyte (N/L) ratio has recently emerged as a new inflammation marker for cardiovascular disease.

Aim: In this study, we hypothesised that CAE could be associated with more severe inflammation compared to obstructive coronary artery disease (O-CAD) with regard to N/L ratio values.

Methods: A total of 405 patients with isolated CAE, O-CAD and insignificant CAD (controls) were enrolled. Severity of isolatedCAE was determined according to the Markis classification. N/L ratio values were compared between the three groups.

Results: We determined that the patients with isolated CAE had significantly elevated N/L ratio values compared to O-CADand control groups (2.5 vs. 1.9, p < 0.001 and vs. 1.6, p < 0.001, respectively). In multivariate analysis adjusted for age, sex, diabetes meliteis (DM) and hypertension, N/L ratio was independently associated with the presence (N/L ratio, OR = 2.48, 95% CI 2.03–3.02, p < 0. 001) and severity (DM, OR = 2.90, 95% CI 1.02–8.18, p = 0.044, N/L ratio, OR = 1.88, 95% CI 1.47–2.41, p = 0.004) of isolated CAE. ROC curve analysis revealed that a N/L ratio value of > 2.06 identified the patients with isolated CAE.

Conclusions: We showed that patients with isolated CAE had a significantly higher N/L ratio than patients with O-CAD and control groups. This finding suggests that a more severe inflammatory process could be involved in the development of CAE.