The neutrophil to lymphocyte ratio improves the positive predictive value of dobutamine stress echocardiography

The neutrophil to lymphocyte ratio (NLR) predicts cardiovascular events. The aim of this study was to determine whether NLR improved the positive predictive value (PPV) of dobutamine stress echocardiography (DSE) in patients with stable coronary artery disease (CAD). We conducted a retrospective review of laboratory and DSE data from the medical records of 1,012 patients who were divided into two groups according to the presence of ischemia and further subdivided into three groups according to the extent of ischemia (nonischemic segments, 1-3 ischemic segments, or > 3 ischemic segments). NLRs were compared among these groups. NLRs increased in patients with ischemia and correlated with the number of ischemic segments (P < 0.001). The optimal cutoff value of NLR determined using receiver operating characteristic analysis was > 2.04, and the diagnostic value of NLR for discriminating patients with ≥ 50% coronary stenosis in at least one of the coronary arteries from those without significant CAD was high [area under the curve (AUC) = 0.671, standard error = 0.052, P < 0.001, 95% confidence interval (CI) = 0.569-0.773)]. An NLR cutoff value of > 2.04 predicted CAD presence with significant stenosis (62.10% sensitivity and 64.10% specificity). PPV of DSE for a significant coronary artery lesion identified using coronary angiography was 73.8% (95% CI = 75.1-88.5, P < 0.001, AUC = 0.818). On including a cut-off value of > 2.04 for NLR in this multivariable predictive model, the AUC value slightly increased to 0.905 (95% CI = 85.4-95.6) and PPV of DSE increased from 73.8% to 92.6%. NLR improved PPV of DSE for patients with stable CAD.