NT-proBNP in Children With Left to Right Shunt and Dilated Cardiomyopathy

B-type natriuretic peptide (BNP) levels are elevated in children with congenital heart disease involving a left-to-right shunt (LRS) and are also raised in dilated cardiomyopathy (DCM). As far as we know, there are few reports in the literature comparing the change of the NT-proBNP in LRS and DCM especially in the pediatric age group.

The aim of the study was to compare the changes of the NT-proBNP in pediatric patients with LRS and DCM. Correlation between the levels of NT-proBNP and the echocardiographic parameters in both groups was determined.

A total of 30 children (13 males and 17 females) participated in the study. There were 11/30 (36.7%) DCM and 19/30 (63.3%) LRS. The control group consisted of 44 healthy infants and children. Manifestations of heart failure (decompensation) were recorded. The NT-pro BNP levels were measured. The following Echo parameters were assessed: systolic function (ejection fraction and fraction shortening), pulmonary to systemic flow (Qp/Qs) in LRS, pulmonary flow and pulmonary artery pressure (SPAP) and LV diastolic function (E-wave, A-wave, E/A ratio and deceleration time).

Clinically 17/30 (56.7%) (11 of the LRS and 5 of the DCM) were decompensated. Significant shunt was present in 15/19 (78.9%) in LRS. Systolic dysfunction was presented in 5/30 (16.7%) cases (4 patients were DCM and one case was LRS). Two types of diastolic dysfunction, impaired relaxation in 5/22 (22.7%) patients and restrictive-like filling pattern in 5/16 (31.2 %) were observed. The NT-Pro BNP level was significantly elevated 11 and 16 times in the LRS and DCM groups respectively. Negative significant correlations were observed between the levels of NT-ProBNP and the following echo variables; EDD, LAD, E wave and E/A ratio in the LRS patients. Positive significant correlations were observed between the levels of NT-ProBNP and the following echo variables; PAP and QP/QS in the LRS. Both the PAP and QP/QS were higher in the elevated NT-Pro BNP group compared to the normal level group. The NT-Pro BNP level was elevated in all 17/30 (56.7%) decompensated patients (11 were LRS, 6 were DCM) (P = 0.002). However, the level was elevated in only 7/13 (23.3%) of the compensated patients (3 were LRS, 4 were DCM) (P = 0.002). The NT-Pro BNP level was also elevated in 18/19 cases with pulmonary hypertension (P = 0.01). Finally, we conclude that the NT-ProBNP level is elevated in both LRS and DCM in pediatric age. This elevation is more remarkable with heart failure and increased PAP in both diseased groups. The level was also elevated and correlated to Qp/Qs in the LRS patients.

So, we recommend the use of NT-ProBNP as a routine marker for following up patients with heart failure and pulmonary hypertension in LRS and DCM.