Safety and effectiveness of bronchial thermoplasty when FEV₁ is less than 50%

Background: Randomized clinical trials of bronchial thermoplasty (BT) were conducted in patients with a baseline FEV₁ greater than 50%. There is a paucity of data regarding BT in patients with more severe obstruction, and consequently these patients are often excluded from receiving BT. The purpose of this study was to compare safety and efficacy outcomes in a large cohort of patients with an FEV₁ less than 50% with those of a cohort of less obstructed patients. Methods: Consecutive patients with severe asthma were drawn from the Australian BT Registry. Patients were grouped into (1) those with a baseline prebronchodilator FEV₁ % predicted < 50% (n = 32) or (2) those with an FEV₁ ≥ 50% (n = 36). Adverse outcomes were defined as (1) remaining in hospital longer than the planned 24-hour admission posttreatment or (2) being readmitted to hospital for any cause within 30 days of a treatment. Efficacy outcomes were evaluated 6 months after BT. Results: More severely obstructed patients were no more likely to have experienced any adverse event. Significant improvements in Asthma Control Questionnaire score, exacerbation frequency, reliever medication use, and requirement for daily oral steroids were observed in both groups, and were of a similar degree. Conclusions: This study demonstrates that BT can confidently be offered to patients with asthma with an FEV₁ that is 30% to 50% of predicted without risk of more frequent or more severe adverse events, and with the expectation of the same degree of response as patients with better lung function.