Amino-terminal pro-B-type natriuretic peptide testing in neonatal and pediatric patients.

Concentrations of amino-terminal pro-B-type natriuretic peptides (NT-proBNP) are often markedly elevated immediately after birth and typically decrease to normal concentrations after the first week of life. Despite these early life elevations (which likely reflect activity of the natriuretic peptide system to assist in mobilization of fluid in the neonatal period), NT-proBNP has been shown to be useful for the diagnosis or exclusion of heart failure (HF) in the neonate, infant, adolescent, and older child. After the resolution of the normative early-life elevations of NT-proBNP, it is reasonable to use age-adjusted cut points suggested for younger adults (<50 years), namely levels <300 ng/L to "rule out" HF, and >450 ng/L to "rule in" HF. In children with congenital heart disease with or without symptoms of HF, NT-proBNP concentrations are typically elevated and may be prognostically useful. Furthermore, NT-proBNP may be useful for the identification of patients treated with cardiotoxic chemotherapy at risk for the subsequent development of cardiomyopathy. Knowledge of expected concentrations of NT-proBNP at varying stages of life is important to optimally utilize this assay in the pediatrics setting.