B-type Natriuretic Peptide and Amino-terminal Pro-B-type Natriuretic Peptide in Pediatric Patients with Pulmonary Arterial Hypertension

Abstract

B-type natriuretic peptide (BNP) and the amino-terminal fragment (NTproBNP) correlate with clinical variables, but have not been simultaneously studied in a large number of pediatric patients with pulmonary arterial hypertension (PAH). The purpose of our investigation was to compare BNP and NTproBNP with clinical indicators of disease in a pediatric PAH population for which biomarkers are much needed. We retrospectively compared BNP and NTproBNP levels with exercise capacity, echocardiographic data, and hemodynamics in PAH patients under 21 years old. Two hundred sixty-three blood samples from 88 pediatric PAH patients were obtained, with BNP and NTproBNP drawn at the same time. There was a correlation between BNP and NTproBNP with mean pulmonary arterial pressure/mean systemic arterial pressure ratio (r= 0.40, P < .01; r= 0.45, P < .01; respectively), mean right atrial pressure (r= 0.48, P < .01; r= 0.48, P < .01), and tricuspid regurgitant velocity (r= 0.36, P < .01; r= 0.41, P < .01). BNP and NTproBNP are associated with 6-minute walk distance, mean pulmonary arterial pressure, mean pulmonary arterial pressure/mean systemic arterial pressure ratio, mean right atrial pressure, pulmonary vascular resistance index, and tricuspid regurgitant velocity when investigated longitudinally. On the average, a 1-unit increase in log BNP or NTproBNP was associated with 4.5 units × m(2) or 3.4 units × m(2) increase in pulmonary vascular resistance index, respectively. There was a strong correlation between log BNP and log NTproBNP measurements (r= 0.87, P < .01). In pediatric PAH, BNP and NTProBNP are strongly correlated and predict changes in clinical variables and hemodynamics. In a cross-sectional analysis, NTproBNP correlated with echocardiographic and exercise data better than BNP; NTproBNP showed less within patient variability over time; therefore, NTproBNP can add additional information toward predicting these clinical measurements.