Exercise-Induced Pulmonary Arterial Hypertension in Pediatric and Young Adult Patients With Cystic Fibrosis

Abstract

PURPOSE: Pulmonary arterial hypertension (PAH) has long been appreciated in cystic fibrosis (CF). Exercise-induced PAH is an evolving disorder that has not been well described in CF. METHODS: A prospective cohort study was performed in CF patients with advanced lung disease undergoing evaluation for lung transplantation. The right heart catheterization (RHC) was performed with access via the right internal jugular vein with advancement of the catheter to the pulmonary artery wedge position under fluoroscopic guidance. There was continuous monitoring of the pulmonary artery pressure (PAP) while supine and during exercise on a stationary bicycle. RESULTS: Five adult (mean age 26.8 ± 10.1 years) CF patients (3 males, 2 females) underwent RHC for evaluation for lung transplantation. The cohort had advanced lung disease with mean (± SD) FEV1 of 0.99 ± 0.17 (range 0.82-1.17) Liters and 26 ± 3 (range 23-30) % predicted. Each patient had no significant pathology or evidence of PAH on echocardiography. Using a paired t test, there was a significant elevation in the mean (± SD) PAP when comparing supine position to exercise, 24.80 ± 3.11 mmHg vs 45.20 ± 5.72 mmHg, P = 0.0003. There was no evidence of left heart failure with mean (± SD) pulmonary capillary wedge pressures of 8.6 ± 1.8 (range 6-11) mmHg. CONCLUSIONS: An abnormal pulmonary vascular response to exercise in CF was identified in pediatric and young adult patients with advanced lung disease. The RHC was well tolerated and should possibly be considered sooner in CF patients with severe lung disease. Echocardiography was not helpful in estimating the PAP in this small cohort of CF patients.