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.