Albuterol and Dynamic Hyperinflation in Idiopathic Pulmonary Arterial Hypertension

Albuterol and Dynamic Hyperinflation in Idiopathic Pulmonary Arterial Hypertension

The purpose of this study is to determine if dynamic hyperinflation seen in patients with idiopathic pulmonary artery hypertension (iPAH) improves with albuterol therapy.

Only a few small studies have evaluated the relationship between iPAH, expiratory flow limitation, and exercise dyspnea. While not all patients with iPAH demonstrate airway involvement, those who demonstrate dynamic hyperinflation (DH), defined as a variable and temporary increase in end-expiratory lung volume, report increased dyspnea with exertion on maximal testing. There is a continued need for adjuvant therapy in iPAH, and bronchodilators have the potential to ameliorate dyspnea during exercise, which could lead to improved quality of life in this disabling condition. This study will investigate the presence of airway involvement in this population as measured by dynamic hyperinflation, and if there is any improvement in function with the use of inhaled albuterol.

Inclusion Criteria:

• 18 years of age or greater.
• Idiopathic Pulmonary Arterial Hypertension, or Familial Pulmonary Arterial Hypertension.
• Forced expiratory flow 75% (FEF75%) of ≤ 65% of predicted.

Exclusion Criteria:

• Clinical instability or change in medication therapy in preceding 3 months.
• Allergy or intolerance to inhaled albuterol.
• Body mass index > 30
• Active tobacco use, or > 10 pack-year smoking history.
• Lung disease other than pulmonary hypertension
• Forced expiratory volume in 1 second (FEV1) ≤ 80% of predicted.
• Pregnancy
• Inability to perform pulmonary function testing.
• Inability to perform cardiopulmonary exercise testing.
• Supplemental oxygen requirement.
• Inability to read and understand English.
• Historical 6-minute walk distance <150 meters