Factors affecting N-terminal pro-B-type natriuretic peptide levels in preterm infants and use in determination of haemodynamic significance of patent ductus arteriosus.

ABSTRACT

This study aimed to investigate factors affecting N-terminal pro-B-type natriuretic peptide (NTproBNP) in preterm infants and the ability of NTproBNP to predict haemodynamically significant patent ductus arteriosus (HsPDA). Prospective cohort study of 51 infants < 30 weeks gestation. Blood NTproBNP and heart ultrasound were performed on day of life 3, 10, 28 and 36 weeks corrected age. NTproBNP levels analysed for prediction of HsPDA. The effect of gestational age, ventilation, hypoxia, bronchopulmonary dysplasia (BPD), creatinine and haemoglobin levels on NTproBNP levels were investigated. Infants with HsPDA had higher mean (SD) day 3 NTproBNP (1840 pmol/L (1058) versus 178 pmol/L (140) p < 0.001). Receiver operator curves of day 3 NTproBNP for prediction of day 3 and day 10 HsPDA had an area under the curve of 0.98 and 0.94, respectively. A chosen day 3 NTproBNP value of ≥ 287 pmol/L for the prediction of day 3 HsPDA correctly classified 92% (sensitivity 92%, specificity 92%). NTproBNP demonstrated only modest ability to predict severe BPD. Chronological but not gestational age affected NTproBNP. Ventilation, hypoxia and haemoglobin levels did not influence NTproBNP but creatinine level was positively correlated. CONCLUSION: Day 3 NTproBNP is a useful biomarker to predict HsPDA and may be a valuable tool in future trial design. What is Known • NTproBNP is a cardiac hormone used to diagnose and monitor cardiac dysfunction in adults and has been shown to be higher in premature infants with haemodynamically significant ductus arteriosus (HsPDA). What is new • NTproBNP is highly predictive of ultrasound-defined HsPDA and may be a useful tool for further triage • Early NTproBNP higher in infants who develop severe BPD and with renal impairment but not affected by gestational age, recent exposure to hypoxia or haemoglobin levels while late levels unexpectedly higher in those without BPD or HsPDA.