266 - Anatomical Phenotypes for Severe Bronchopulmonary Dysplasia Modestly Impact Short- and Long-term Clinical Outcomes

Bronchopulmonary dysplasia is the most common complication of prematurity and its incidence is increasing.  Infants with severe BPD have increased mortality and have adverse long-term respiratory and neurological outcomes.  Characterizing anatomical subtypes of BPD might help tailor therapies and ventilation strategies for optimizing outcomes.  In this pilot study, we classified anatomical subtypes of BPD to investigate association with clinical outcome.

Objective: 1. To determine if a specific phenotype, or combination of phenotypes, is associated with the risk for death and/or tracheostomy at 1 year of age.
2. To investigate the association between each individual phenotype (or in combination) with long-term respiratory support, use of diuretics and pulmonary hypertension medication, type of feeding delivery, growth trajectory, and rates of rehospitalization.

Design/Methods:

Retrospective cohort study of all infants with severe BPD (2001 NICHD definition) who were discharged from Children’s Mercy Hospital NICU that were discharged between Jan 1, 2019, and Dec 31, 2020.  Data was collected from electronic medical records after receiving IRB approval.  Patients with a complete evaluation (Chest XR, Chest CT, Bronchoscopy, and echocardiogram) were classified into various clinical BPD phenotypes, namely, severe parenchymal (or alveolar), airway, vascular, or any combination of these three.

Results: Among the 100 infants who had severe BPD, 29 had a full evaluation, and constituted the study cohort.  Among the 29 infants, 62% had severe parenchymal disease, 69% had airway disease, and 62% had pulmonary vascular disease.  Airway disease as an individual phenotype was statistically associated with combined outcome of death/tracheostomy (p = 0.014), assisted ventilation at discharge (p = 0.011) and 6 months of age (p = 0.027).  The presence of all three phenotypes occurred most (31%) as shown in Figure 1 and was also significant associated with death/tracheostomy (p = 0.043).

Conclusion(s): The presence of airway phenotype and its combination with severe parenchymal and vascular phenotypes was significantly associated with a combined outcome of death/tracheostomy and other long-term morbidities in infants with severe BPD.  Identification of specific clinical phenotype in infants with severe BPD will lead to individualized approach to therapy.  This study is limited by the small sample size and therefore further study is needed to confirm these findings.