398 - Early Prediction of Bronchopulmonary Dysplasia–Associated Pulmonary Hypertension in Extremely Preterm Infants

Publication Number: 1381.398

Samuel Gentle, Yale School of Medicine, New Haven, CT, United States; Waldemar Carlo, University of Alabama, Birmingham, AL, United States; Namasivayam Ambalavanan, University of Alabama School of Medicine, Birmingham, AL, United States

Background: Previously developed models to predict infants' risk for bronchopulmonary dysplasia (BPD) have not included estimates for BPD-associated pulmonary hypertension (BPD-PH).

Objective: We hypothesized that clinical covariates collected over the first postnatal month can accurately predict risk for BPD-PH.

Design/Methods: This was a retrospective, single center cohort study of infants born at < 29 weeks' gestation between 2017 and 2024. BPD-PH was defined as the presence of any of the following criteria during hospitalization: tricuspid regurgitation jet >2.5 m/s, bidirectional shunting through either a septal defect or ductus arteriosus, or an eccentricity index >1.2. Given collinearity between BPD severity and BPD-PH, considered predictors included those previously evaluated in the NICHD BPD estimation models: birth weight, gestational age, respiratory support on postnatal day one, fraction of inspired oxygen on postnatal day one, race, gender, antenatal corticosteroid exposure, and surgical necrotizing enterocolitis. Patent ductus arteriosus (PDA) was also considered in the model given recent literature associating PDA with BPD-PH development. PDA status at each time point was based on echocardiographic findings, with presence coded only through the last study showing a PDA. Models were developed using logistic regression models developed on postnatal days 1, 7, 14, and 28.

Results: Among the 777 infants available for analysis, 643 infants did not develop pulmonary hypertension compared to 134 infants who developed BPD-PH. Infants who developed pulmonary hypertension were born at a lower birth weight (median 620 vs 870; p< 0.001) and lower gestational age (median 24 vs 27; p< 0.001) (Table 1). Respiratory support differed between infants with and without BPD-PH over the first postnatal month (Figure 1). Predictive accuracy of included covariates increased with postnatal age with a C-statistic of 0.88 on postnatal day 28 using the variables of respiratory support, gestational age, birth weight, hemodynamically significant PDA, fraction of inspired oxygen, sex, and surgical necrotizing enterocolitis (Table 2).

Conclusion(s): Clinical covariates can accurately predict the BPD-PH phenotype with increasing predictive utility over the first postnatal month. Model informed cut-off values may be incorporated into the design of clinical trials aimed at specifically reducing risk for BPD-PH.

Table 1
PAS_2025_BPD-PH Prediction Table 1.pdf

Table 2
PAS_2025_BPD-PH Prediction Table 2.pdf

Figure 1. Respiratory support over the first postnatal month among infants with and without pulmonary hypertension.
Panel A: Mode of respiratory support among infants without pulmonary hypertension. Panel B: Mode of respiratory support among infants with pulmonary hypertension. Proportions represent the percentage of infants receiving each mode of respiratory support on postnatal days 1, 7, 14, and 28. Modes included high-frequency ventilation, conventional mechanical ventilation, non-invasive positive pressure ventilation (NIPPV), continuous positive airway pressure (CPAP), nasal cannula, oxyhood, and room air.