Patients with severe asthma and severe airflow obstruction are no more likely to experience an adverse event following bronchial thermoplasty than patients with better lung function, according to study results published in CHEST.
The study included 70 consecutive patients with severe asthma who were enrolled in the Australian Bronchial Thermoplasty Registry between June 2014 and December 2018. Patients were placed into 2 cohorts based on whether they had a baseline prebronchodilator forced expiratory volume in 1 second (FEV1) percent predicted <50% (n=32) or a baseline prebronchodilator FEV1 ≥50% (n=36). Adverse events and efficacy of treatment at 6 months following bronchial thermoplasty were assessed.
Efficacy was examined by assessing the change in Asthma Control Questionnaire (ACQ) score from baseline. Secondary outcomes included changes in the number of patient-reported oral corticosteroid-requiring exacerbations in the 6 months after treatment completion vs 6 months before treatment, the daily dose of oral corticosteroid, daily short-acting reliever use, and prebronchodilator FEV1 % predicted.
Baseline ACQ values changed by -1.5±1.0 in patients with FEV1 <50% and -1.7±1.3 in patients with FEV1 ≥50%. Over the 6-month follow-up period, exacerbations changed by -2.2±3.6 in patients with FEV1 <50% and -3.9±3.7 in patients with FEV1 ≥50% (P =.053). Any adverse event was reported equally among patients, irrespective of obstruction severity. In addition, patients with FEV1 <50% had a 15.4%±28.8% change in FEV1, whereas patients with FEV1 ≥50% had a 2.8%±24.9% change in FEV1. Both groups also experienced improvements in reliever medication use and requirement for daily oral steroids.
The researchers added that more use of bronchial thermoplasty may help further improve safety of the treatment and that “it may well be the case that, as experience builds, adverse event rates will fall.”
Langton D, Ing A, Fielding D, et al. Safety and effectiveness of bronchial thermoplasty when FEV1 is less than 50. CHEST. 2020;157(3):509-515.