Diagnostic accuracy of B-type natriuretic hormone for congenital heart disease in the first month of life

BACKGROUND: The goal of the present study was to evaluate the diagnostic accuracy of B-type natriuretic hormone (BNP) assay in children with congenital heart disease (CHD) in the first month of life. METHODS: BNP was measured in 152 neonates with CHD; 154 healthy children matched for age were used as controls. BNP was measured with a fully automated platform (Triage BNP reagents, Access Immunoassay Systems, Beckman Coulter, Inc., Fullerton, CA, USA). RESULTS: BNP values were significantly higher (p<0.0001) in newborns and infants with CHD compared with control (CHD patients: median 1167.5 ng/L, range 25-54,447 ng/L; healthy children: median 150.5 ng/L, range 5-866 ng/L). The diagnostic accuracy of BNP was assessed using the receiver operating characteristic (ROC) analysis, taking into account the three different groups divided according to age. Group 1: all CHD patients and healthy newborns and infants as a whole (i.e., from birth to the 30th day of life); Group 2: from the 1st to 3rd day of life; Group 3: from the 4th to 30th day of life. The area under the curve (AUC) of the ROC curve for Group 3 (0.935) was significantly higher than that for Group 1 (0.843, p=0.009) and Group 2 (0.769, p=0.0003), while the AUC values of Group 1 and Group 2 were not significantly different (p=0.191). CONCLUSIONS: BNP may be considered a useful marker for screening in the integrated approach of newborns, infants and children with suspected CHD. However, the accuracy of the BNP assay varies greatly during the first month of extra-uterine life, showing the lowest diagnostic accuracy in the first 3 days after birth. After the second week of life, the biomarker becomes more accurate in ruling in CHD.