Association between early pulmonary arterial pressure measurements and bronchopulmonary dysplasia or mortality in very preterm infants: a prospective cohort study

BACKGROUND: Prematurity is a significant risk for bronchopulmonary dysplasia related pulmonary artery pressure. OBJECTIVE: To determine the association between pulmonary artery pressure in the early days of life and the development of bronchopulmonary dysplasia or mortality. METHODS: This prospective observational cohort study included infants born at <32 weeks and weighing <1500 g. Pulmonary artery pressure was measured between postnatal days 3 and 7. Pulmonary hypertension was defined as systolic pulmonary artery pressure ≥40 mm Hg or systolic pulmonary artery pressure/systolic blood pressure >0.5 (pulmonary hypertension criterion-1). Infants were categorised into pulmonary hypertension and non-pulmonary hypertension groups. The primary endpoint was bronchopulmonary dysplasia or mortality. Receiver operating characteristic analysis established a new threshold value for predicting bronchopulmonary dysplasia or mortality (pulmonary hypertension criterion-2). Infants were reanalysed according to new criteria. RESULTS: A total of 329 infants were included in this study. Moderate-to-severe pulmonary hypertension was identified in 24% (n=79) of the infants. The pulmonary hypertension group exhibited a significantly lower gestational age, lower birth weight and a higher incidence of small for gestational age. Systolic pulmonary artery pressure >25 mm Hg or systolic pulmonary artery pressure/systolic blood pressure >0.35 was defined as the pulmonary hypertension criterion-2. Logistic regression analysis identified pulmonary hypertension criterion-2 as an independent risk factor for moderate-to-severe bronchopulmonary dysplasia or mortality (OR 2.67, 95% CI 1.3 to 5.51, p<0.01). CONCLUSION: Pulmonary artery pressure exceeding 25 mm Hg in the early days of life may be considered a potential risk factor for bronchopulmonary dysplasia or mortality.