The efficacy and safety of bronchial thermoplasty in severe persistent asthma on extended follow-up.

Background: Asthma is a common condition and there remains a subset of patients who are poorly controlled on maximal therapy. Bronchial thermoplasty (BT) is a bronchoscopic therapy using radiofrequency energy to reduce airway smooth muscle, which has been shown to improve asthma control although further evidence regarding long-term efficacy and safety is required.

Aim: We aimed to demonstrate safety and efficacy of BT on extended follow-up. Our initial experience with this group was previously reported in 2016, where patients were shown to have a significant improvement in asthma control test (ACT) scores 1-year post-treatment.

Design: We carried out a retrospective observational study of seven patients who underwent BT between 2012 and 2013 in an Irish severe asthma centre. The primary endpoint was change in ACT scores from baseline to present.

Methods: Seven patients underwent BT at a tertiary referral centre in Ireland. ACT scores and data on hospital admissions, exacerbations, maintenance corticosteroid requirements, rescue bronchodilator use and forced expiratory volume for 1 s (FEV1) prior to the procedure and on extended follow-up were collected. Mean follow-up was 49.42 months.

Results: A trend towards improvement was seen in median hospitalisations (respective values for median over 12 months 3, 1 P = 0.059) and ACT scores, from 9 to 13 (P = 0.249). Mean FEV1 was 1.68 l prior to treatment and 1.46 l 4 years post-treatment (P = 0.237). There was no mortality among the group.

Conclusions: These data support the safety of BT and suggest extended efficacy.