PREDICTIVE VALUE OF THE NEUTROPHIL-TO-LYMPHOCYTE RATIO FOR THE DIAGNOSIS OF PNEUMONIA IN NORMOTHERMIC DYSPNEIC PATIENTS WITH CHRONIC HEART FAILURE IN THE EMERGENCY DEPARTMENT

Background: Differentiating pneumonia from chronic heart failure (HF) in normothermic subjects in the emergency department (ED) is significantly difficult. Objective: This study aimed to evaluate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) in establishing the diagnosis of pneumonia in normothermic subjects with chronic HF in the ED. Methods: This study included 523 adult dyspneic patients with chronic HF presenting in the ED. We categorized the selected patients into the nonpneumonia group (NPG) and the pneumonia group (PG), and the patients' serum white blood cell (WBC), neutrophil, and lymphocyte counts, NLR, and C-reactive protein (CRP) levels were measured upon arrival in the ED. Subsequently, we compared their predictive powers after performing a propensity score-matching (PSM) analysis. Results: The PG included 120 (22.9%) patients. After performing PSM, the mean NLR was significantly higher in the PG than in the NPG group (p < 0.001). According to the receiver operating characteristic area under the curve (AUC) analysis of inflammatory markers, the AUC of the NLR was significantly higher than that of WBCs, neutrophils, lymphocytes, and CRP. Conclusion: The predictive value of the NLR was significantly higher than that of WBCs, neutrophils, lymphocytes, and CRP. Therefore, NLR may be a useful adjunctive marker to establish the early diagnosis of pneumonia in normothermic patients with chronic HF in the ED. (C) 2020 Elsevier Inc. All rights reserved.