D15-08 Persistent Pulmonary Vascular Disease Over the Preschool Age in Children With Bronchopulmonary Dysplasia: A Catheterization-based Study

Abstract Background Bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) is a major cause of death in extremely preterm infants. While echocardiography often suggests BPD-PH resolution by age 2, our previous right heart catheterization (RHC) studies indicated that most affected infants still had persistent pulmonary vascular disease (PVD) and mild PH at that time. The long-term hemodynamic status into later childhood is unknown. Objective To evaluate the longitudinal hemodynamic status of patients with BPD-PH through the preschool years using serial RHC. Methods We conducted a single-center, prospective observational cohort study enrolling 125 infants born at less than 28 weeks’ gestation (Jan 2018-Dec 2024). Patients developing BPD-PH were managed in a specialized follow-up clinic. The protocol included a planned first RHC around age 2 and a subsequent, follow-up RHC during the preschool years (approx. 4-6 years) for a subset of patients. Results Fourteen patients (11.2%) were diagnosed with BPD-PH (median gestation 24 weeks; median birth weight 603 g). Ten (71%) had received sildenafil by 40 weeks postmenstrual age. In most cases, PH resolved on echocardiography during follow-up. Nine of the 14 patients underwent the first RHC at a median age of 25 months. This evaluation revealed persistent, mild PH, with a median mean pulmonary arterial pressure (mPAP) of 20 mmHg and a median pulmonary vascular resistance index (PVRi) of 2.72 WU⋅m2. Pulmonary wedge angiography showed reduced peripheral pulmonary arteries (PAs) in 5 of these 9 patients (56%). At this time, 7 of 9 were still on sildenafil. Three patients from the cohort underwent a follow-up RHC at a median age of 5 years. One had experienced worsening PH requiring tadalafil initiation at age 3. This later RHC confirmed persistent hemodynamic abnormalities (median mPAP 20 mmHg; median PVRi 2.7 WU⋅m2), remaining at the upper limit of normal. Persistent PA hypoplasia was noted in all three patients on pulmonary wedge angiography. Conclusion This extended RHC study provides novel evidence that PVD in BPD-PH persists beyond the preschool age even though echocardiography derived PH resolved. The sustained elevated PVRi and PA hypoplasia suggest an underlying fixed vasculopathy. This cohort requires continued, long-term specialized follow-up to monitor for late-onset PH and guide therapeutic decisions. This abstract is funded by: None