Clinical implication of plasma natriuretic peptides in children with ventricular septal defect

Background: There is little information available concerning plasma concentrations of B-type natriuretic peptide (BNP) in children with a ventricular septal defect. The aim of the present study was to determine hemodynamic factors that control plasma concentrations of BNP and the clinical implications of BNP compared with atrial natriuretic peptide (ANP) in children with ventricular septal defect. Methods: Fifty-nine patients with ventricular septal defect (28 boys and 31 girls) without pulmonary vascular disease were enrolled. The patients' ages ranged from 3 months to 13 years (mean 3.1 years). Plasma BNP and ANP were determined by immunoradiometric assay. Hemodynamic variables derived from cardiac catheterization were analyzed in terms of correlation with BNP and ANP. Results: It was found that plasma BNP significantly positively correlated with ANP (ANP = 2.1 x BNP + 25 pg/mL; r = 0.81, P < 0.0001) and BNP never exceeded ANP in the present patient series. Plasma BNP as well as ANP significantly positively correlated with pulmonary to systemic flow ratio (r = 0.65 and r = 0.59, respectively) and mean pulmonary artery pressure (r = 0.72 and r = 0.68, respectively). In addition, plasma BNP of ≥20 pg/mL and ANP of ≥50 pg/mL identified children with mean pulmonary artery pressure of ≥20 mmHg with a sensitivity of 82% and 97%, respectively, and a specificity of 89% and 84%, respectively. Conclusion: Plasma BNP and ANP reflect pressure and volume loads to the pulmonary artery and right ventricle and may help to identify children with ventricular septal defect complicated by pulmonary hypertension that demands early intervention.