Pretreatment asthma control test score as a predictive score for clinical remission after bronchial thermoplasty in younger patients with severe asthma and preserved lung function

Abstract

Objective

Bronchial thermoplasty (BT) decreases the incidence of asthma exacerbations, emergency room visits, and hospitalizations among patients with severe asthma. Predictors of BT effectiveness remain unclear as its mechanism of action and invasiveness remain obscure. This study aimed to identify factors that could predict BT outcomes.

Methods

Two respiratory physicians treated 20 consecutive patients with severe asthma using BT. The patients were assigned to groups based on clinical remission following an expert consensus proposed in 2020. Predictors of clinical remission were analyzed using asthma control test (ACT) score, pulmonary function and blood tests, and fractional exhaled nitric oxide.

Results

At baseline, the median age was 44 years (interquartile range [IQR], 31.0–52.8), and pre-bronchodilator (pre-BD) percent predicted forced expiratory volume in one second (%FEV1) was 85.9% (IQR, 74.8–100.5). Six (30%) patients achieved clinical remission. Among the patients treated with biologics, 20% had clinical remission, and 20% discontinued biologic therapy. The pre-BT ACT score was significantly lower in the group with than without remission (11.0 [IQR, 8.0–14.5] vs. 15.0 [IQR, 11.0–17.3], p = .016). Adverse events did not significantly differ between the groups.

Conclusions

To the best of our knowledge, this is the first study to use clinical remission as a criterion for evaluating BT efficacy. The pre-BT ACT score might a the predict response to BT in younger adult patients with severe asthma and pre-BD %FEV1 ≥ 70%.

Keywords:

• Asthma control test
• biologic
• bronchial thermoplasty
• clinical remission
• percent predicted forced expiratory volume in one second

Acknowledgments

The authors thank all the participants of the study.

Author contributions

F.K. conceived and designed the study, interpreted the data, and drafted the original manuscript. H.C. significantly contributed to data analysis and interpretation. F.K. and K.K. performed bronchial thermoplasty. A.T., A.M., S.O., C.Y., N.T., and K.Y. were responsible for data curation and provided assistance while performing bronchial thermoplasty. K.K., H.K., K.T., and T.K. made substantial contributions to revising the manuscript drafts. All authors have reviewed and approved the final version of the manuscript, and they agree to be accountable for their respective contributions to the work.

Ethical approval

This study was approved by the Ethics Committee of the Seirei Yokohama Hospital (approval No. 2022-029; approval date: 9 February 2023).

Patient consent

Consent forms were obtained from each participant of this retrospective study. An opt-out method was employed for patients who could not be contacted, allowing them or their families to decline participation.

Disclosure statement

The authors have no conflicts of interest.

Funding

No financial support was provided for this study.

Data availability statement

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.