Abstract
Background: Late pulmonary hypertension (PH) affects up to 50% of infants with severe bronchopulmonary dysplasia and is associated with increased mortality and morbidity. Because of its insidious nature and poor outcomes, screening of high-risk neonates has been proposed with algorithms using heart ultrasound and biomarkers used in Europe, America and Canada but not currently in New Zealand (NZ). Feasibility and equity of access are important considerations when implementing new screening programmes.
Methods: We conducted a thorough narrative review of the current literature on infantile late pulmonary hypertension and the current available evidence and proposed methods for its screening. To understand the current New Zealand context for this condition and what a national screening programme may look like, we first surveyed the availability of neonatal echocardiography and current practice for late PH screening in all 23 NZ perinatal centres. We then developed and piloted a screening protocol using heart ultrasound and NTproBNP testing for at risk infants (<28 weeks’ gestation, <1000g birth weight, foetal growth restriction, early pulmonary hypertension) aligned with best practice evidence to explore feasibility in a NZ setting. Clinical characteristics and short-term morbidity and mortality data were collected.
Results: Neonatal echocardiography was available in all 6 major neonatal units and half of all perinatal centres in NZ. Screening and follow-up practices differed markedly around the country. Late PH was present in 30% of infants screened with a mortality rate of 33%, which was consistent with international studies. NTproBNP levels were raised in infants with PH at both 36 and 40 weeks compared to infants without PH and may be best used as a screening adjunct to heart ultrasound at 36 weeks (NTproBNP level >130pmol/L has 80% sensitivity of detecting future or existing PH with a specificity of 71%). In our study infants with lower gestational age and lower birth weight were more likely to develop PH and have poorer outcomes.
Conclusions: Screening for PH with heart ultrasound is feasible in a tertiary neonatal setting and was supported by both consumers and neonatal medical staff. NTproBNP may be a useful adjunct to heart ultrasound to help identify which infants need to be referred to tertiary centres for PH screening and management. Further information is needed to develop equitable screening tools and referral pathways for infants born in smaller perinatal centres.