Predictive value of elevated neutrophil-lymphocyte ratio on cardiac mortality in patients with stable coronary artery disease

Background: An association between white blood cell count (WBC), severity of coronary artery disease (CAD) and survival has been described in patients with acute coronary syndrome. Our aim was to analyze the predictive ability for cardiac events of differential WBC, which is still not well characterized, against established risk factors in angiographically proven CAD patients. Methods: We prospectively evaluated complete blood count, biomarkers of inflammation [(C-reactive protein (CRP) and serum iron (SI)], glucose/lipid metabolism [(fasting glucose (FG), total, high-density lipoprotein (HDL) and low-density lipoprotein cholesterol] and established risk factors in 422 consecutive ischemic patients with angiographically documented stable CAD. On a 3-year follow-up, cardiac death and non-fatal myocardial infarction (MI) were considered as end-points. Results: At multivariate analysis neutrophil to lymphocyte ratio (N/L) emerged as independent predictor of cardiac death (HR 8.13; p=0.02) together with CRP, left ventricular ejection fraction (LVEF), FG, HDL and SI. CRP, LVEF, and HDL showed an independent prognostic value for cardiac death and non-fatal MI. Event-free survival according to N/L tertiles was 99% for the first tertile (1.23±0.26), 96.5% for the second (2.05±0.29), and 88.8% for the third one (5.19±3.81). Conclusions: N/L is an independent predictor of cardiac mortality in stable CAD patients.