Direct comparison of B-type natriuretic peptide and N-terminal pro-BNP for assessment of cardiac function in a large population of symptomatic patients

Backgrounds: B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NTproBNP) levels showed frequent discrepancies in individual patients. Objectives: The aims were 1) to compare the abilities of BNP and NTproBNP for the detection of left ventricular systolic dysfunction (LVSD) or diastolic dysfunction (LVDD) in the symptomatic patients, and 2) to assess the direct correlation and its independent determinants between them. Methods: 1032 patients with dyspnea underwent BNP and NTproBNP measurements simultaneously. 967/1032 (93.7%) patients underwent echocardiography. Using the receiver operation characteristic curve analyses for the detection of LVSD (EF<45%) or advanced LVDD, the area under the curves (AUC) of both biomarkers was compared according to age, gender, body mass index (BMI), hemoglobin (Hb), and glomerular filtration rate (eGFR). Using multiple regression analysis, the direct correlation and its independent determinants were identified between them. Results: In the entire population, the AUCs of BNP and NTproBNP had no significant differences (LVSD: 0.909 vs. 0.893, p=0.20; advanced LVDD: 0.897 vs. 0.879, p=0.13). In patients with BMI<25, the AUCs of BNP were significantly higher than those of NTproBNP (LVSD: 0.897 vs. 0.869, p=0.03; advanced LVDD: 0.916 vs. 0.885, p=0.02). They had strong correlation (r=0.895, p<0.001) and LVEF, eGFR<60 ml/min, Hb<12 g/dl and use of diuretics were the independent determinants between them. Conclusion: BNP and NTproBNP displayed strong correlation and near-identical performances for the screening of cardiac dysfunction. However, LVEF, renal function, Hb and use of diuretics should be considered for clinical interpretation.