Address for Correspondence/Yaz›şma Adresi: Dr. Serap Çuhadar, Atatürk Eğitim Hastanesi,

doi:10.5152/akd.2014.4944 Objective: Preexisting renal failure diminishes the excretion of N-Terminal Pro-Brain Natriuretic Peptide (NT-proBNP), therefore limits the diagnostic value of this peptide for concomitant heart failure. The aim of this study was to evaluate the association between NT-proBNP and the stages of renal dysfunction in a typical population attended to emergency department with acute dyspnea. Methods: In this cross-sectional study, all patients underwent clinical evaluation, laboratory assessment of NT-proBNP, and echocardiographic examinations. Among subjects, 54.5 % were diagnosed as heart failure. Grouping variables according to renal function capacity and ejection fraction, independent variables were compared with Kruskal-Wallis or ANOVA with posthoc tests. Correlation and linear regression analysis were done to analyze the variables associated with NT-proBNP. The diagnostic performance of NT-proBNP was evaluated by receiver-operat-ing characteristic (ROC) curve. Results: Serum median NT-proBNP level in patients with severe renal impairment was significantly higher than moderate and mildly decreased renal functions (p=0.001). In patients with moderate and severe left ventricular failure, NT-proBNP was significantly higher compared with normal subjects (LVEF>55%) (p=0.040, and 0.017, respectively). Renal dysfunction was associated with heart failure in 56 % of the patients. The area under the ROC curve of NT-proBNP for identifying left ventricular failure in patients with renal failure (eGFR<90 mL/min/1.73 m2) was 0.649 and reached significant difference (95 % CI:0.548-0.749, p=0.005)