B-type natriuretic peptide in paediatric patients with congenital heart disease

AIMS: To examine the diagnostic value of B-type natriuretic peptide (BNP) plasma concentration in congenital heart disease. METHODS AND RESULTS: BNP was measured in 288 consecutive patients (mean age 6.0 +/- 6.4 years) with left-to-right shunt, left or right heart obstruction, tetralogy of Fallot, functionally univentricular heart, or impaired left ventricular function and compared with age- and gender-specific normal values, and to haemodynamic and echocardiographic data. BNP increased with decreasing left ventricular shortening fraction (r = -0.80; P < 0.001). In patients with left-to-right shunt, BNP was increased (mean SDS +1.64; P < 0.001) and positively correlated (P < 0.001) to shunt volume (r = 0.66), systolic right ventricular pressure (r = 0.69), mean pressure of the pulmonary artery (r = 0.66), and pulmonary resistance (r = 0.59). There was no correlation between BNP and invasive pressure gradient or extent of ventricular hypertrophy in patients with left or right heart obstruction. In patients with tetralogy of Fallot, BNP was not significantly increased. Patients with functionally univentricular heart had elevated BNP plasma levels (mean SDS +1.39; P < 0.001) without decrease after volume unloading by cavopulmonary connection. CONCLUSION: In children with congenital heart defects, plasma BNP correlates closely to ventricular function. BNP plasma levels do not reflect directly the extent of ventricular pressure or volume work, but mirror the impairment of the loaded ventricles. Normal BNP cannot exclude pathology, but reflects a compensated status of the heart.