Role of Plasma N-Terminal Pro-Brain Natriuretic Peptide (Nt-Pro-Bnp), a Diagnostic and Prognostic Biomarker of Acute Dyspnoea of Cardiac Diseases

Abstract

BACKGROUND Early detection and accurate diagnosis of heart failure remain a huge clinical challenge in patients with acute dyspnoea of various aetiologies. Different biomarkers of left ventricular dysfunction are being studied to differentiate acute cardiogenic from noncardiogenic dyspnoea. Amongst those, Brain Natriuretic Peptide (BNP) is an important biomarker for diagnosing acute stage of cardiac dyspnoea. The aim of this study is to assess the Plasma N-Terminal Pro-Brain Natriuretic Peptide (NT-ProBNP) level in acute dyspnoea of various aetiologies and to establish the diagnostic or prognostic value of plasma NT-ProBNP in acute dyspnoea of cardiac diseases. MATERIALS AND METHODS In our study, we have taken 84 cases of acute dyspnoea. The acute dyspnoea above 15 years of age were included in the study. Whereas dyspnoea due to chest trauma, renal insufficiency (serum creatinine > 2.5 mg/dL), previously known as valvular heart diseases and severe coronary ischaemia identified as > 0.1 MV ST-segment elevation or ST depression on 12-lead ECG were excluded from the study. After taking patient's history, the clinical examination with routine blood test, electrocardiography and chest x-ray were done. In addition, blood sample was collected for NT-ProBNP measurement. RESULTS In our study group, out of 84 cases Male= 55 (65.4%) and Female= 29 (34.6%). Among those cases 40 (47.6%) had acute cardiac dyspnoea, whereas 44 (52.4%) had non-cardiac dyspnoea. The mean + SD NT-ProBNP concentration of cases with acute cardiac dyspnoea was (4539.7 + 4342.9 pg/ mL), which was significantly higher than the cases with non-cardiac dyspnoea (136.6 + 94.7 pg/ mL), (P < 0.00001). On the evaluation of acute heart failure according to NYHA (New York Heart Association classification), 44 (52.4%) had NYHA Class-I symptoms, 3 (7.5%) had NYHA Class-II symptoms, 10 (25%) had Class-III symptoms and 27 (67.5%) had Class-IV symptoms that demonstrate the significant relationship of NT-ProBNP of NYHA symptom severity with analysis using ANOVA (P < 0.00001). The median NT-ProBNP level was 150 pg/ mL (IQR-713 pg/ mL) in patients with left ventricular ejection fraction (LVEF) > 50% and 4580 pg/ mL (IQR-3180 pg/ mL) in those with LVEF < 50% (P < 0.00001). CONCLUSION The serum NT-ProBNP measurement is a useful parameter for diagnosing cardiac causes of dyspnoea and also acute heart failure as per NYHA class. It can be used for early detection and management of acute heart failure.