Search

Rationale: Bronchial thermoplasty (BT) is a bronchoscopic treatment for severe asthma targeting airway smooth muscle (ASM). Observational studies have shown ASM mass reduction after BT, but appropriate control groups are lacking. Furthermore, as treatment response is variable, identifying optimal candidates for BT treatment is important. Objectives: First, to assess the effect of BT on ASM mass, and second, to identify patient characteristics that correlate with BT response. Methods: Patients with severe asthma ( n  = 40) were randomized to immediate ( n  = 20) or delayed ( n  = 20) BT treatment. Before randomization, clinical, functional, blood, and airway biopsy data were collected. In the delayed control group, reassessment, including biopsies, was performed after 6 months of standard clinical care, followed by BT. In both groups, post-BT data including biopsies were obtained after 6 months. ASM mass (% positive desmin or α-smooth muscle actin area in the total biopsy) was calculated with automated digital analysis software. Associations between baseline characteristics and Asthma Control Questionnaire and Asthma Quality of Life Questionnaire (AQLQ) improvement were explored. Measurements and Main Results: Median ASM mass decreased by >50% in the immediate BT group ( n  = 17) versus no change in the delayed control group ( n  = 19) ( P  = 0.0004). In the immediate group, Asthma Control Questionnaire scores improved with -0.79 (interquartile range [IQR], -1.61 to 0.02) compared with 0.09 (IQR, -0.25 to 1.17) in the delayed group ( P  = 0.006). AQLQ scores improved with 0.83 (IQR, -0.15 to 1.69) versus -0.02 (IQR, -0.77 to 0.75) ( P  = 0.04). Treatment response in the total group ( n  = 35) was positively associated with serum IgE and eosinophils but not with baseline ASM mass. Conclusions: ASM mass significantly decreases after BT when compared with a randomized non-BT-treated control group. Treatment response was associated with serum IgE and eosinophil levels but not with ASM mass.

Rationale: Adverse events have limited the use of bronchial thermoplasty (BT) in severe asthma. Objectives: We sought to evaluate the effectiveness and safety of using 129 Xe magnetic resonance imaging ( 129 Xe MRI) to prioritize the most involved airways for guided BT. Methods: Thirty subjects with severe asthma were imaged with volumetric computed tomography and 129 Xe MRI to quantitate segmental ventilation defects. Subjects were randomized to treatment of the six most involved airways in the first session (guided group) or a standard three-session BT (unguided). The primary outcome was the change in Asthma Quality of Life Questionnaire score from baseline to 12 weeks after the first BT for the guided group compared with after three treatments for the unguided group. Measurements and Main Results: There was no significant difference in quality of life after one guided compared with three unguided BTs (change in Asthma Quality of Life Questionnaire guided = 0.91 [95% confidence interval, 0.28-1.53]; unguided = 1.49 [95% confidence interval, 0.84-2.14]; P  = 0.201). After one BT, the guided group had a greater reduction in the percentage of poorly and nonventilated lung from baseline when compared with unguided (-17.2%; P  = 0.009). Thirty-three percent experienced asthma exacerbations after one guided BT compared with 73% after three unguided BTs ( P  = 0.028). Conclusions: Results of this pilot study suggest that similar short-term improvements can be achieved with one BT treatment guided by 129 Xe MRI when compared with standard three-treatment-session BT with fewer periprocedure adverse events.

Bronchial thermoplasty (BT) is a novel treatment of patients with severe asthma who continue to be symptomatic despite maximal medical treatment. It aims to reduce the smooth muscle mass in the airways by delivering controlled thermal energy to the airway walls during a series of three bronchoscopies. Randomized controlled clinical trials of BT in severe asthma have not been able to show a reduction in airway hyperresponsiveness or change in FEV(1) but have suggested an improvement in quality of life, as well as a reduction in the rate of severe exacerbations, emergency department visits, and days lost from school or work. Strict inclusion and exclusion criteria of these trials resulted in the elimination of patients with severe asthma who experienced more than three exacerbations per year. Therefore, the generalizability of this treatment to the broader severe asthma population still needs to be determined. The short-term adverse events consist primarily of airway inflammation and occasionally more severe events requiring hospitalization. Long-term safety data are evolving and have shown thus far clinical and functional stability up to 5 years after BT treatment. Additional studies on BT are needed to establish accurate phenotyping of positive responders, durability of effect, and long-term safety.

Rationale: Bronchial thermoplasty (BT) is a bronchoscopic procedure in which controlled thermal energy is applied to the airway wall to decrease smooth muscle., Objectives: To evaluate the effectiveness and safety of BT versus a sham procedure in subjects with severe asthma who remain symptomatic despite treatment with high-dose inhaled corticosteroids and long-acting beta(2)-agonists., Methods: A total of 288 adult subjects (Intent-to-Treat [ITT]) randomized to BT or sham control underwent three bronchoscopy procedures. Primary outcome was the difference in Asthma Quality of Life Questionnaire (AQLQ) scores from baseline to average of 6, 9, and 12 months (integrated AQLQ). Adverse events and health care use were collected to assess safety. Statistical design and analysis of the primary endpoint was Bayesian. Target posterior probability of superiority (PPS) of BT over sham was 95%, except for the primary endpoint (96.4%)., Measurements and Main Results: The improvement from baseline in the integrated AQLQ score was superior in the BT group compared with sham (BT, 1.35 +/- 1.10; sham, 1.16 +/- 1.23 [PPS, 96.0% ITT and 97.9% per protocol]). Seventy-nine percent of BT and 64% of sham subjects achieved changes in AQLQ of 0.5 or greater (PPS, 99.6%). Six percent more BT subjects were hospitalized in the treatment period (up to 6 wk after BT). In the posttreatment period (6-52 wk after BT), the BT group experienced fewer severe exacerbations, emergency department (ED) visits, and days missed from work/school compared with the sham group (PPS, 95.5, 99.9, and 99.3%, respectively)., Conclusions: BT in subjects with severe asthma improves asthma-specific quality of life with a reduction in severe exacerbations and healthcare use in the posttreatment period. Clinical trial registered with www.clinialtrials.gov (NCT00231114).

Rationale: Bronchial thermoplasty (BT) is designed to reduce airway smooth muscle and improve asthma control., Objectives: This study was conducted to determine the safety and efficacy of this procedure in subjects with symptomatic, severe asthma., Methods: Adults who were symptomatic despite treatment with fluticasone or equivalent at more than 750 mug/day, a long-acting beta(2)-agonist, and other medications, which could include 30 mg or less of oral prednisolone/day, were randomized to BT or to a control group. After treatment, subjects entered a 16-week steroid stable phase (Weeks 6-22), a 14-week steroid wean phase (Weeks 22-36), and a 16-week reduced steroid phase (Weeks 36-52)., Measurements and Main Results: BT resulted in a transient worsening of asthma symptoms. Seven hospitalizations for respiratory symptoms occurred in 4 of 15 BT subjects during the treatment period. Five hospitalizations were within 3 days of treatment. Two subjects had segmental collapse involving the most recently treated lobe; one required bronchoscopy and aspiration of a mucus plug. There were no hospitalizations during this period in the 17 control subjects. The rate of hospitalizations was similar in both groups in the post-treatment period. At 22 weeks, BT subjects had significant improvements versus control subjects in rescue medication use (-26.6 +/- 40.1 vs. -1.5 +/- 11.7 puffs/7 d, P < 0.05), prebronchodilator FEV(1)% predicted (14.9 +/- 17.4 vs. -0.94 +/- 22.3%, P = 0.04), and Asthma Control Questionnaire scores (-1.04 +/- 1.03 vs. -0.13 +/- 1.00, P = 0.02). Improvements in rescue medication use and Asthma Control Questionnaire scores remained significantly different from those of controls at 52 weeks., Conclusions: BT is associated with a short-term increase in asthma-related morbidity. However, there is preliminary evidence of long-lasting improvement in asthma control. Clinical trial registered with www.clinicaltrials.gov (NCT 00214539).

Rationale: Bronchial thermoplasty (BT) reduces the potential for smooth muscle-mediated bronchoconstriction by reducing the mass of smooth muscle in the walls of conducting airways., Objectives: This study was conducted to examine the safety and impact on lung function and airway responsiveness of BT over 2 yr., Methods: The safety of BT was studied in 16 subjects with mild to moderate asthma. Baseline and 12-wk post-treatment measurements included spirometry, methacholine challenge, daily diary recordings of peak flow, symptoms, and medication usage. Subjects completed follow-up evaluations at 12 wk, 1 yr, and 2 yr., Measurements and Main Results: The procedure was well tolerated; side effects were transient and typical of what is commonly observed after bronchoscopy. All subjects demonstrated improvement in airway responsiveness. The mean PC(20) increased by 2.37 +/- 1.72 (p < 0.001), 2.77 +/- 1.53 (p = 0.007), and 2.64 +/- 1.52 doublings (p < 0.001), at 12 wk, 1 yr, and 2 yr post-procedure, respectively. Data from daily diaries collected for 12 wk indicated significant improvements over baseline in symptom-free days (p = 0.015), morning peak flow (p = 0.01), and evening peak flow (p < or = 0.007). Spirometry measurements remained stable throughout the study period., Conclusions: BT is well tolerated in patients with asthma and results in decreased airway hyperresponsiveness that persists for at least 2 yr.