Abstract 17909: Pulmonary Hypertension is Associated With Morbidity, Mortality and Prolonged Hospitalization in Premature Infants With Bronchopulmonary Dysplasia

Introduction: Pulmonary hypertension (PH) is a common comorbidity in premature infants with bronchopulmonary dysplasia (BPD). We sought to assess factors associated with PH and determine its association with morbidity and mortality in a large contemporary BPD cohort.

Hypothesis: PH is independently associated with increased mortality in premature neonates with BPD.

Methods: This single center retrospective cohort study identified all infants with BPD born 2010-2021. BPD severity was defined by previously established literature guidelines. PH was defined at ≥ 36 weeks post-menstrual age by echocardiography (RV pressure > 40 mmHg, eccentricity index > 1.1), cardiac catheterization (mean pulmonary artery pressure > 20 mmHg, pulmonary capillary wedge pressure ≤ 15 mmHg and pulmonary vascular resistance ≥ 3 iWU), or treatment with enteral pulmonary vasodilators. Outcomes of death, tracheostomy, hospital duration and comorbidities were compared against a positive PH diagnosis. Univariate and multivariable models were used to assess associations of PH and covariates with clinical outcomes.

Results: The sample cohort consisted of 726 neonates (median Gestational Age: 26 weeks [IQR 25.0, 28.0], 48.4% female) with PH diagnoses in 190 (26%). 92 PH patients received enteral PH therapy, with 84 (44%) on mono and 8 (5%) on dual therapy, which was discontinued by a median age 9.5 months (IQR 6.6 - 15.3). Lower gestational age (p=0.016), higher BPD severity (p<0.0001), and non-white race (p=0.002) were associated with PH in multivariable models. PH was associated with higher mortality rate (18% vs 5%, p <0.0001), higher tracheostomy rate (50% vs 16%, p<0.0001), and longer hospital duration (median 116 (IQR 61-182) vs 58 (IQR 11-132) days, p = 0.001) in univariate and multivariable models. PH was associated with pulmonary vein stenosis (9% vs 1%, p=0.001), but not NEC, ROP or IVH after adjusting for covariates.

Conclusions: This study demonstrates that BPD-PH carries an independent risk for mortality and morbidity including BPD severity, tracheostomy, pulmonary vein stenosis, and longer hospitalization. Enteral pulmonary vasodilators were used in almost half of all PH patients, with resolution of PH within 1 year of diagnosis in the majority of infants.