Spirometric Response to Bronchial Thermoplasty in Patients With Severe Asthma

This trial is studying whether a procedure called bronchial thermoplasty — which uses a thin tube to deliver controlled heat inside the airways — can improve breathing test results in people with severe asthma that is difficult to control with medications alone. **You may be eligible if...** - You are 18 years of age or older - You have been diagnosed with severe asthma that is not well-controlled - Your breathing test (called spirometry) shows reduced airflow, meaning your lungs have trouble pushing air out quickly — this is measured as a low FEV1 score - You are considered a good candidate for the bronchial thermoplasty procedure by your doctor **You may NOT be eligible if...** - You are under 18 years of age - You do not have a confirmed diagnosis of severe asthma - Your doctor has determined you are not a suitable candidate for the procedure Talk to your doctor to see if this trial is right for you.