Asthma control during the year after bronchial thermoplasty

Abstract

Background: Bronchial thermoplasty is a bronchoscopic procedure to reduce the mass of airway smooth muscle and attenuate bronchoconstriction. We examined the effect of bronchial thermoplasty on the control of moderate or severe persistent asthma.

Methods: We randomly assigned 112 subjects who had been treated with inhaled corticosteroids and long-acting beta2-adrenergic agonists (LABA) and in whom asthma control was impaired when the LABA were withdrawn to either bronchial thermoplasty or a control group. The primary outcome was the frequency of mild exacerbations, calculated during three scheduled 2-week periods of abstinence from LABA at 3, 6, and 12 months. Airflow, airway responsiveness, asthma symptoms, the number of symptom-free days, use of rescue medication, and scores on the Asthma Quality of Life Questionnaire (AQLQ) and the Asthma Control Questionnaire (ACQ) were also assessed.

Results: The mean rate of mild exacerbations, as compared with baseline, was reduced in the bronchial-thermoplasty group but was unchanged in the control group (change in frequency per subject per week, -0.16+/-0.37 vs. 0.04+/-0.29; P=0.005). At 12 months, there were significantly greater improvements in the bronchial-thermoplasty group than in the control group in the morning peak expiratory flow (39.3+/-48.7 vs. 8.5+/-44.2 liters per minute), scores on the AQLQ (1.3+/-1.0 vs. 0.6+/-1.1) and ACQ (reduction, 1.2+/-1.0 vs. 0.5+/-1.0), the percentage of symptom-free days (40.6+/-39.7 vs. 17.0+/-37.9), and symptom scores (reduction, 1.9+/-2.1 vs. 0.7+/-2.5) while fewer puffs of rescue medication were required. Values for airway responsiveness and forced expiratory volume in 1 second did not differ significantly between the two groups. Adverse events immediately after treatment were more common in the bronchial-thermoplasty group than in the control group but were similar during the period from 6 weeks to 12 months after treatment.

Conclusions: Bronchial thermoplasty in subjects with moderate or severe asthma results in an improvement in asthma control. (ClinicalTrials.gov number, NCT00214526 [ClinicalTrials.gov].).