To study the values of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in the evaluation of cardiac function in children with congenital heart disease (CHD).
Seventy-one children with CHD were classified to two groups: congestive heart failure (CHF) (n=23) and non-CHF (n=48). Thirty-five age-matched normal children were used as the control group. Plasma BNP content was measured using a microparticle enzyme immunoassay (MEIA) on the AxSYM. Plasma NT-proBNP content was measured using an automated electrochemiluminescence immunoassay on a Roche Modular Analytics E170 analyzer. Echocardiographic parameters, including left ventricular end diastolic dimension index (LVEDDI) and left ventricular ejection fraction (LVEF), were measured.
Plasma BNP and NT-proBNP contents in the CHF group were significantly higher than those in the non-CHF group (P<0.01). The non-CHF group had higher plasma BNP and NT-proBNP contents than the control group (P<0.01). LogBNP and LogNT-proBNP values were negatively correlated with the LVEF in the CHF group (r=-0.64, r=-0.67 respectively, P<0.01), and they were positively correlated with the LVEDDI (r=0.58, r=0.76 respectively, P<0.01). In the non-CHF group, LogBNP and LogNT-proBNP values were not correlated with the LVEF, but a positive correlation was found between the LogNT-proBNP value and the LVEDDI (r=0.35, P<0.05). Using plasma BNP content > or =149.8 pg/mL and NT-proBNP content > or =820.1 pg/mL as cut-off values for diagnosing CHF respectively, the sensitivities were 87.0 % and 91.3% respectively, the specificities were 91.7% and 97.9% respectively, and the areas under the ROC curves were 0.935 and 0.987 respectively.
Both BNP and NT-proBNP can be useful in assessment of cardiac function and diagnosis of CHF in children with CHD. NT-proBNP appears to be more sensitive and specific in the diagnosis of CHF than BNP.