Abstract 12213: Exercise Induced Pulmonary Hypertension in Long Term Survivors of Congenital Diaphragmatic Hernia

Introduction: Survivors of congenital diaphragmatic hernia (CDH) are at risk of pulmonary hypertension (PH) due to pulmonary hypoplasia and other pulmonary vascular abnormalities. Hypothesis: Exercise stress echocardiography (ESE) may detect PH, not apparent on echocardiography at rest, in children and young adults with repaired CDH. Methods: Single center retrospective cohort study of all CDH survivors who underwent ESE at Boston Children’s Hospital (January 2006 – June 2020). Severity of PH was assessed at baseline and after exercise. Patients were assigned to one of two categories based on right ventricular pressure: group 1: no or mild PH after exercise; and group 2: moderate or severe PH after exercise (right ventricular pressure ≥ 60 mmHg or ≥ ½ systemic blood pressure). Results: During the study period 84 CDH patients (70% male) underwent 173 ESE with a median age 8.1 (4.8 – 19.1) years at first ESE. Sixty-four patients were classified as group 1, 11 as group 2, and 9 were unable to be classified due to inconclusive ESE. Moderate to severe PH after exercise was found in 8 (10%) patients with no or mild PH at rest. Risk factors for PH after exercise included larger CDH defect size, patch repair, use of extracorporeal membrane oxygenation, and supplemental oxygen at discharge in univariate analysis (Table 1). Exercise and pulmonary function test parameters associated with a group 2 test included higher VE/VCO2 slope, lower peak oxygen saturation, and lower percent predicted FEV1 and FEV1/FVC ratio. Nine of 11 group 2 patients had a change in management based on ESE. PH was found in all 5 group 2 patients with cardiac catheterization after ESE, including 3 patients with no or mild PH on baseline ESE. Conclusions: Among long term CDH survivors, ESE identified 10% with moderate-severe exercise induced PH indicating ongoing pulmonary vascular abnormalities. Further studies are needed to optimally define screening and treatment for patients with repaired CDH.