Phenotyping Asthma for Bronchial Thermoplasty

Asthma currently affects over 300 million individuals worldwide and the number of the
affected patient is continuously increasing. Approximately 10% of asthmatics have poorly
controlled, severe symptoms.

The exact mechanisms behind the development of asthma are unknown. However, the excessive
contraction of airway smooth muscle leading to airway constriction is thought to be
responsible for the majority of the symptoms of asthma. A new treatment option, termed
bronchial thermoplasty, can offer relief for individuals with severe asthma. Bronchial
thermoplasty works by reducing smooth muscle with thermal energy.

This new imaging technology, called optical coherence tomography (OCT) is the first imaging
modality that is capable to visualize airway smooth muscle in humans. In this study the
investigators will examine the asthmatic airways before and after bronchial thermoplasty to
learn about how airways respond to this treatment. The long term goal of this study is to use
OCT to look at the airways with the hope of helping clinicians monitor and predict the
response to bronchial thermoplasty.

During the scheduled bronchial thermoplasty procedure, OCT imaging will be performed. The
study imaging will add less than 10 minutes to the time required for the standard
procedure.Twelve months following the completion of bronchial thermoplasty, the investigators
will ask the participants to return to the hospital to undergo follow-up tests including a CT
scan and a bronchoscopy procedure with repeat OCT imaging. The investigators expect these
test to be accomplished in 2 additional visits.

Inclusion Criteria:

1. Patient undergoing elective bronchial thermoplasty

2. Patient is between the ages of 18 and 60

3. Patient is able to give informed consent

4. Negative pregnancy test for all female of childbearing potential who are sexually
active and not using contraception, are seeking to become pregnant, or who are
nursing.

5. Nonsmoking (<5 pack year tobacco exposure)

6. No history of co-existing lung disease

7. Meet American Thoracic Society criteria for diagnosis of asthma with either/or

1. Bronchodilator response to albuterol (≥12% change in FEV1)

2. Positive methacholine bronchoprovocation (PC20 < 25 mg/ml)

Exclusion Criteria:

1. Patients who are pregnant.

2. Patient does not meet the requirements to undergo clinical bronchial thermoplasty, as
determined by the treating physician