Evaluation of the effectiveness of bronchial thermoplasty in patients with severe asthma in the real world two years after bronchial thermoplasty treatment

Abstract

Objective: To assess the effectiveness of bronchial thermoplasty (BT) in "real-world" patients with severe asthma at 2 years post therapy. Method: Outcomes of 70 patients with severe asthma undergoing bronchial thermoplasty from March 2014 to November 2017 in China-Japan Friendship Hospital were retrospectively analyzed two years post therapy. The scores of Asthma Control Test (ACT) and Mini Asthma Quality of Life Questionnaire (mini-AQLQ), the number of severe exacerbations, emergency department visits and hospitalizations for asthma symptoms in the past year, indicators of pulmonary function including forced expiratory volume in one second (FEV(1)), FEV(1) as a percentage of predicted value (FEV(1)%pred) and FEV(1)/forced vital capacity (FEV(1)/FVC), maintenance asthma medications, the cost of asthma drugs and the total annual cost of asthma treatment were evaluated and analyzed before and 2 years after BT therapy, and the subjective assessment about effectiveness of BT were given by the patients. Results: Before and 2 years after BT, the numbers of subjects suffering severe exacerbations in the past year were 70 (100%) and 37 (52.9%), and the numbers of total severe exacerbations were 575 and 162 respectively. The numbers of patients having emergency department visits due to asthma exacerbation were 46 (65.7%) and 9 (12.9%), and the numbers of emergency department visits were 186 and 19 respectively. The numbers of patients hospitalized due to asthma exacerbation were 43 (61.4%) and 16 (22.9%), and the numbers of total hospitalizations were 124 and 24, respectively. The rate of severe exacerbation, emergency department visit and hospitalization were significantly reduced two years after the treatment by 71.9%, 88.9% and 83.3% (all P<0.001). The scores of ACT and mini-AQLQ were significantly increased [22 (21, 24) vs 17 (13, 19), (5.57±0.89) vs (3.83±0.92); both P<0.001]. Two years after BT, 4 patients (5.7%) were weaned off inhaled corticosteroids (ICS) and long-acting β(2)-agonist (LABA), while 14 patients (37.8%) were weaned off oral corticosteroid (OCS), with daily dose of ICS and OCS significantly decreased (both P<0.05). The proportion of patients treated with montelukast sodium and theophylline was also significantly reduced after BT (40.0% vs 81.4%, 27.1% vs 71.4%; both P<0.001). In addition, the indicator of FEV(1), FEV(1)%pred and FEV(1)/FVC ratio were all greatly improved two years after the treatment [2.27 (1.84, 2.82) vs 2.10 (1.70, 2.61) L, (76.8±19.5)% vs (72.5±19.8)%, (66.3±13.6)% vs (63.8±13.0)%; all P<0.05]. The annual cost for asthma drug and asthma treatment after BT were significantly decreased (P<0.001). Fifty-nine patients (84.3%) subjectively assessed the treatment as effective. Conclusion: The bronchial thermoplasty in "real-world" patients with severe asthma could significantly improve the asthma control, lung function and quality of life, and reduce severe exacerbations, emergency department visits and hospitalizations for asthma symptoms, while the maintenance asthma medications, the cost of asthma drugs and the total annual cost of asthma treatment are significantly decreased.