Bronchial thermoplasty in severe asthma in Australia

Plethysmography Derived Gas Trapping Lacks Utility in Predicting Response to Bronchial Thermoplasty

There is a paucity of literature on measurable baseline parameters predicting response and guiding selection for bronchial thermoplasty. This study examines whether baseline gas trapping, as assessed by plethysmography, is associated with a response to bronchial thermoplasty at 12 months.

43 consecutive patients with severe asthma (mean±sd age 57.6±13.3 years) were evaluated at baseline and 12 months post bronchial thermoplasty. Data collected at both time points included spirometry, body plethysmography and four clinical outcome measures, namely Asthma Control Questionnaire (ACQ) score, annual exacerbation frequency, maintenance oral corticosteroid requirement and short-acting β-agonist use.

At baseline, participants had severe airflow obstruction (forced expiratory volume in 1 s 49.1±15.8%) with marked gas trapping (residual volume (RV) 150.3±40.8%, RV/total lung capacity (TLC) 51.3±10.5%), poor symptom control (ACQ 3.3±1.0) and frequent exacerbations (median 4, interquartile range 8). 12 months after bronchial thermoplasty, significant improvements were observed in all four clinical outcome measures. However, baseline RV and RV/TLC were not significantly associated with changes in ACQ nor any other clinical outcome measure, and changes in RV and RV/TLC did not significantly correlate with a change in any clinical outcome measure.

Plethysmography-derived gas trapping does not demonstrate utility in predicting response and guiding selection for bronchial thermoplasty. An improvement in gas trapping was not associated with positive clinical outcomes, suggesting that this may not be the dominant mode of action of bronchial thermoplasty in generating clinical improvement.

This study examined whether measuring gas trapping by plethysmography could be used to predict response to bronchial thermoplasty; no association was foundhttps://bit.ly/3tJN1X8

Bronchial Thermoplasty Global Registry (BTGR): 2-year results

OBJECTIVES

Bronchial thermoplasty (BT) is a device-based treatment for subjects ≥18 years with severe asthma not well controlled with inhaled corticosteroids and long-acting beta-agonists. The Bronchial Thermoplasty Global Registry (BTGR) collected real-world data on subjects undergoing this procedure.

DESIGN

The BTGR is an all-comer, prospective, open-label, multicentre study enrolling adult subjects indicated for and treated with BT.

SETTING

Eighteen centres in Spain, Italy, Germany, the UK, the Netherlands, the Czech Republic, South Africa and Australia PARTICIPANTS: One hundred fifty-seven subjects aged 18 years and older who were scheduled to undergo BT treatment for asthma. Subjects diagnosed with other medical conditions which, in the investigator's opinion, made them inappropriate for BT treatment were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

Baseline characteristics collected included demographics, Asthma Quality of Life Questionnaire (AQLQ), Asthma Control Test (ACT), medication usage, forced expiratory volume in one second and forced vital capacity, medical history, comorbidities and 12-month baseline recall data (severe exacerbations (SE) and healthcare utilisation). SE incidence and healthcare utilisation were summarised at 1 and 2 years post-BT.

RESULTS

Subjects' baseline characteristics were representative of persons with severe asthma. A comparison of the proportion of subjects experiencing events during the 12 months prior to BT to the 2-year follow-up showed a reduction in SE (90.3% vs 56.1%, p<0.0001), emergency room visits (53.8% vs 25.5%, p<0.0001) and hospitalisations (42.9% vs 23.5 %, p=0.0019). Reductions in asthma maintenance medication dosage were also observed. AQLQ and ACT scores improved from 3.26 and 11.18 at baseline to 4.39 and 15.54 at 2 years, respectively (p<0.0001 for both AQLQ and ACT).

CONCLUSIONS

The BTGR demonstrates sustained improvement in clinical outcomes and reduction in asthma medication usage 2 years after BT in a real-world population. This is consistent with results from other BT randomised controlled trials and registries and further supports improvement in asthma control after BT.

TRIAL REGISTRATION NUMBER

NCT02104856.

Applying personalized medicine to adult severe asthma

Background: Severe asthma is a heterogeneous disease that consists of various phenotypes driven by different pathways. Associated with significant morbidity, an important negative impact on the quality of life of patients, and increased health care costs, severe asthma represents a challenge for the clinician. With the introduction of various antibodies that target type 2 inflammation (T2) pathways, severe asthma therapy is gradually moving to a personalized medicine approach. Objective: The purpose of this review was to emphasize the important role of personalized medicine in adult severe asthma management. Methods: An extensive research was conducted in medical literature data bases by applying terms such as "severe asthma" associated with "structured approach," "comorbidities," "biomarkers," "phenotypes/endotypes," and "biologic therapies." Results: The management of severe asthma starts with a structured approach to confirm the diagnosis, assess the adherence to medications and identify confounding factors and comorbidities. The definition of phenotypes or endotypes (phenotypes defined by mechanisms and identified through biomarkers) is an important step toward the use of personalized medicine in asthma. Severe allergic and nonallergic eosinophilic asthma are two defined T2 phenotypes for which there are efficacious targeted biologic therapies currently available. Non-T2 phenotype remains to be characterized, and less efficient target therapy exists. Conclusion: Despite important progress in applying personalized medicine to severe asthma, especially in T2 inflammatory phenotypes, future research is needed to find valid biomarkers predictive for the response to available biologic therapies to develop more effective therapies in non-T2 phenotype.

Bronchial thermoplasty for severe asthma: A position statement of the Indian chest society

Bronchial thermoplasty (BT) is an interventional bronchoscopic treatment for severe asthma. There is a need to define patient selection criteria to guide clinicians in offering the appropriate treatment options to patients with severe asthma.

METHODOLOGY

An expert group formed this statement under the aegis of the Indian Chest Society. We performed a systematic search of the MEDLINE and EMBASE databases to extract evidence on patient selection and the technical performance of BT.

RESULTS

The experts agreed that the appropriate selection of patients is crucial and proposed identification of the asthma phenotype, a screening algorithm, and inclusion/exclusion criteria for BT. In the presence of atypical clinical or chest radiograph features, there should be a low threshold for obtaining a thoracic computed tomography scan before BT. The patient should not have had an asthma exacerbation in the preceding two weeks from the day of the procedure. A 5-day course of glucocorticoid should be administered, beginning three days before the procedure day, and continued until the day following the procedure. General Anesthesia (total intravenous anesthesia with a neuromuscular blocker) provides ideal conditions for performing BT. A thin bronchoscope with a 2.0 mm working channel is preferable. An attempt should be made to deliver the maximum radiofrequency activations. Middle lobe treatment is not recommended. Following the procedure, overnight observation in the hospital, and a follow-up visit, a week following each treatment session, is desirable.

CONCLUSION

This position statement provides practical guidance regarding patient selection and the technical performance of BT for severe asthma.

Recent Developments In Bronchial Thermoplasty For Severe Asthma

PURPOSE

Bronchial thermoplasty is approved in many countries worldwide as a non-pharmacological treatment for severe asthma. This review summarizes recent publications on the selection of patients with severe asthma for bronchial thermoplasty, predictors of a beneficial response and developments in the procedure and discusses specific issues about bronchial thermoplasty including effectiveness in clinical practice, mechanism of action, cost-effectiveness, and place in management.

RESULTS

Bronchial thermoplasty is a treatment option for patients with severe asthma after assessment and management of causes of difficult-to-control asthma, such as nonadherence, poor inhaler technique, comorbidities, under treatment, and other behavioral factors. Patients treated with bronchial thermoplasty in clinical practice have worse baseline characteristics and comparable clinical outcomes to clinical trial data. Bronchial thermoplasty causes a reduction in airway smooth muscle mass although it is uncertain whether this effect explains its efficacy since other mechanisms of action may be relevant, such as alterations in airway epithelial, gland, and/or nerve function; improvements in small airway function; or a placebo effect. The cost-effectiveness of bronchial thermoplasty is greater in countries where the costs of hospitalization and emergency department are high. The place of bronchial thermoplasty in the management of severe asthma is not certain, although some experts propose that bronchial thermoplasty should be considered for patients with severe asthma associated with non-type 2 inflammation or who fail to respond favorably to biologic therapies targeting type 2 inflammation.

CONCLUSION

Bronchial thermoplasty is a modestly effective treatment for severe asthma after assessment and management of causes of difficult-to-control asthma. Asthma morbidity increases during and shortly after treatment. Follow-up studies provide reassurance on the long-term safety of the procedure. Uncertainties remain about predictors of response, mechanism(s) of action, and place in management of severe asthma.

Predicting the Response to Bronchial Thermoplasty

BACKGROUND

Although it is established that not all patients respond to bronchial thermoplasty (BT), the factors that predict response/nonresponse are largely unknown.

OBJECTIVES

To identify baseline factors that predict clinical response.

METHODS

The records of 77 consecutive patients entered into the Australian Bronchial Thermoplasty Registry were examined for baseline clinical characteristics, and outcomes measured at 6 and 12 months after BT, such as change in the Asthma Control Questionnaire (ACQ) score, exacerbation frequency, the requirement for short-acting beta-2 agonist (SABA) medication and oral corticosteroids, and improvement in spirometry.

RESULTS

This was a cohort of patients with severe asthma: aged 57.7 ± 11.4 years, 57.1% females, 53.2% of patients taking maintenance oral steroids, 43% having been treated with an mAb, mean FEV₁ of 55.8% ± 19.8% predicted.

RESULTS

BT resulted in an improvement in the ACQ score from 3.2 ± 1.0 at baseline to 1.6 ± 1.1 at 6 months (P < .001). Exacerbation frequency in the previous 6 months reduced from 3.7 ± 3.3 to 0.7 ± 1.2 (P < .001). SABA requirement reduced from 9.3 ± 7.1 puffs/d to 3.5 ± 6.0 (P < .001), and 48.8% of patients were weaned completely off oral steroids. A significant improvement in FEV₁ was observed. Using multiple linear regression models, baseline ACQ score strongly predicted improvement in ACQ score (P < .001). Patients with an exacerbation frequency greater than twice in the previous 6 months showed the greatest reduction in exacerbations (-5.3 ± 2.8; P < .001). Patients using more than 10 puffs/d of SABA experienced the greatest reduction in SABA requirement (-12.4 ± 10.5 puffs, P < .001).

CONCLUSIONS

The most severely afflicted patients had the greatest improvements in ACQ score, exacerbation frequency, and medication requirement.

Efficacy and safety of bronchial thermoplasty in clinical practice: a prospective, longitudinal, cohort study using evidence from the UK Severe Asthma Registry

OBJECTIVES

Use data from the UK Severe Asthma Registry (UKSAR) to assess the efficacy and safety of bronchial thermoplasty (BT) in routine UK clinical practice and to identify characteristics of 'responders'.

DESIGN

Prospective, longitudinal, cohort, multicentre registry study.

SETTING

All (11) UK centres performing BT.

PARTICIPANTS AND INTERVENTION

Patients receiving BT in the UK between 01/06/2011 and 30/09/2016 who had consented to data entry into UKSAR (n=133). Efficacy data were available for 86 patients with a BT baseline and at least one follow-up record. Safety data were available for 131 patients with at least one BT procedure record.

PRIMARY AND SECONDARY OUTCOME MEASURES

Efficacy: AQLQ, ACQ, EuroQol, HADS anxiety and HADS depression scores, FEV₁ (% predicted), rescue steroid courses, unscheduled healthcare visits (A&E/Asthma clinic/GP), hospital admissions and days lost from work/school.

SAFETY

peri-procedural events, device problems and any other safety-related findings. Responder analysis: differences in baseline characteristics of 'responders' (≥0.5 increase in AQLQ at 12 months) and 'non-responders'.

RESULTS

Following Bonferroni correction for paired comparisons, mean improvement in AQLQ at 12 months follow-up compared with BT baseline was statistically and clinically significant (0.75, n=28, p=0.0003). Median reduction in hospital admissions/year after 24 months follow-up was also significant (-1.0, n=26, p<0.0001). No deterioration in FEV₁ was observed. From 28 patients with AQLQ data at BTBL and 12-month follow-up, there was some evidence that lower age may predict AQLQ improvement. 18.9% (70/370) of procedures and 44.5% (57/128) of patients were affected by an adverse event; only a minority were considered serious.

CONCLUSIONS

Improvement in AQLQ is consistent with similar findings from clinical trials. Other efficacy outcomes demonstrated improving trends without reaching statistical significance. Missing follow-up data impacted this study but multiple imputation confirmed observed AQLQ improvement. The safety review suggested BT is being performed safely in the UK.

The acute effects of bronchial thermoplasty on FEV1

BACKGROUND

The most common adverse effect of bronchial thermoplasty (BT) is short-term aggravation of asthma immediately following the procedure. However, the magnitude and duration of this deterioration, and its predisposing factors are yet to be quantitated. This information will be particularly important as BT is extended to include more severely obstructed patients.

METHODS

In this prospective, observational study of 20 consecutive patients with very severe asthma undergoing BT, post bronchodilator FEV₁ was measured in the 30 min prior to surgery, and then 24 h following the 60 procedures. In half the patients, further spirometry was conducted on day 3 and day 7 post procedure.

RESULTS

This study enrolled 12 males and 8 females, mean age 59.7 ± 12.8 years, with mean prebronchodilator FEV₁ of 52.3 ± 15.2% predicted, mean forced expiratory ratio of 51.4 ± 12.6%, and mean improvement in FEV₁ post salbutamol of 19.5 ± 15.3%. All patients were taking inhaled corticosteroids, mean beclomethasone equivalent dose 1950 ± 857 mcg, and 7 patients required maintenance oral corticosteroids for control of their asthma. Twenty four hours after BT, the mean deterioration in post bronchodilator FEV₁ was 166 ± 237 mls (CI 102-224, p < 0.001) or 9.1 ± 15.2% of baseline. This deterioration was significantly greater after upper lobe procedures (p < 0.01, ANOVA repeated measures), where a mean fall in FEV₁ of 17.1 ± 12.6% was observed. The change in FEV₁ post procedure was significantly correlated with the number of radiofrequency activations applied, r = -0.376, p < 0.005. By multivariate analysis, the only factor other than activations predictive of the change in FEV₁ was age, which was protective. When the lower lobes were treated, the postbronchodilator FEV₁ had returned to baseline values by day 3, but patients took 7 days to recover after upper lobe treatments. Despite the severity of asthma in these patients, and the measured deterioration post treatment, there was only one instance of readmission in the 60 procedures.

CONCLUSIONS

The deterioration in lung function after BT is transient and well tolerated, but is greatest after upper lobe treatment, and is significantly related to the number of radiofrequency activations applied.

Bronchial thermoplasty as a treatment for severe asthma: controversies, progress and uncertainties

INTRODUCTION

Bronchial thermoplasty is a licensed non-pharmacological treatment for severe asthma. Area covered: This article considers evidence for the efficacy and safety of bronchial thermoplasty from clinical trials and observational studies in clinical practice. Its place in the management of severe asthma, predictors of response and mechanisms of action are reviewed. Expert commentary: Bronchial thermoplasty improves quality of life and reduces exacerbations in moderate to severe asthma. Morbidity from asthma is increased during treatment. Overall, patients treated in clinical practice have worse baseline characteristics and comparable clinical outcomes to trial data. Follow-up studies provide reassurance on long-term safety. Despite some progress, future research needs to investigate uncertainties about predictors of response, mechanism of action and place in management of asthma.

Usefulness of Bronchial Thermoplasty for Patients with a Deteriorating Lung Function

Bronchial thermoplasty is a novel procedure for patients with severe asthma showing a stable lung function. We herein report two cases with a deteriorating lung function. The lung function tended to improve in one case, while the other case discontinued mepolizumab medication after the procedure. Treatment was performed safely under general anesthesia in both cases. The use of bronchial thermoplasty may therefore be useful for the treatment of patients with a deteriorating lung function.

Bronchial Thermoplasty: A Nonpharmacologic Therapy for Severe Asthma

Bronchial thermoplasty is an innovative treatment for patients with severe asthma and chronic airflow obstruction with an established long-term efficacy and safety profile. This review focuses on the role of bronchial thermoplasty in severe asthma, its mechanism of action, appropriate patient selection, current evidence, and recent developments of this therapy.