Correlation of plasma B-type natriuretic peptide with shunt significance in infants with left-to-right congenital heart disease

Background B-type natriuretic peptide (BNP) is released in response to ventricular hemodynamic stress and heart failure and serves as a sensitive marker of cardiac function. This study examined the correlation between plasma BNP levels and shunt significance in infants with left-to-right congenital heart disease (CHD) and evaluated its diagnostic value as a non-invasive biomarker. Methods In this cross‑sectional observational comparison study, 61 infants with CHD (26 ASD, 25 VSD, and 10 PDA) and 30 matched healthy controls underwent clinical, echocardiographic, and hemodynamic evaluation. Plasma BNP levels were measured by chemiluminescent microparticle immunoassay. Shunt significance was determined by Qp/Qs and mPAP. Results Clinical manifestations such as feeding dyspnea and heart failure were more frequent in VSD and PDA than ASD. Echocardiography revealed significantly higher mPAP in VSD (43.1 ± 13.7 mmHg) and PDA (46.5 ± 16 mmHg) compared with ASD (22.2 ± 5.1 mmHg, P < 0.001). Median plasma BNP levels were significantly higher in PDA (125 pg/ml) than ASD (30 pg/ml), VSD (40 pg/ml), and controls (14.5 pg/ml, P < 0.001). BNP correlated positively with mPAP (r s = 0.67, P < 0.001) and showed excellent diagnostic accuracy for left-to-right shunts (AUC 0.93, cutoff > 23.5 pg/ml, sensitivity 85.5%, specificity 100%). Conclusions Plasma BNP is significantly associated with shunt type and magnitude in infants with CHD and demonstrates excellent diagnostic performance, supporting its role as a valuable non-invasive marker for assessing shunt significance.