Low NT-proBNP levels: An early sign for the diagnosis of ischemic heart failure

Background: N-terminal pro-brain natriuretic peptide (NT-proBNP) is seen to be mostly elevated in patients with acute heart failure (AHF). However, cases of AHF presenting with low NT-proBNP levels have been reported. In this study designed to investigate the factors associated with low NT-proBNP levels in AHF patients, we discovered that etiology and related factors have an influence on NT-proBNP levels. Methods: In this study, 154 AHF patients met the study criteria (117 men, median age 74 years; left ventricular ejection fraction [LVEF] 46 +/- 13%; New York Heart Association [NYHA] classes II-IV). We analyzed the different clinical variables of patients based on plasma NT-proBNP levels. In addition, we identified the differences in NT-proBNP levels between ischemic and non-ischemic etiologies, as well as the relationships between time from symptom onset to ED visit and NT-proBNP levels. Results: The group with low NT-proBNP levels showed an ischemic association, higher LVEF, lower NYHA class and shorter time from symptom onset to ED visit. Plasma NT-proBNP levels were lower in the ischemic group than in the non-ischemic group (P < 0.01). Meanwhile, NT-proBNP levels were relatively low in patients during early phases of AHF hospitalization and increased with time from symptom onset to ED visit (P < 0.01). Conclusion: We inferred that low NT-proBNP levels may infer the ischemic etiology especially in patients with normal LVEF in the early phases of AHF hospitalization. (C) 2016 Elsevier Ireland Ltd. All rights reserved.