Bronchial thermoplasty 'highly effective' for long-term severe asthma control

Nearly half of adults with severe asthma taking maintenance oral steroids were able to completely cease treatment within six months of bronchial thermoplasty, Australian doctors report.

And among those still receiving oral steroids after the novel device-based therapy, their average daily dose dropped by almost 60% in the same period.

“The benefits to such patients in terms of preventing the well-recognised long-term adverse effects of corticosteroids cannot be underestimated,” say clinicians from Frankston Hospital in Melbourne and the Prince of Wales Hospital in Sydney.

Their study, published in Respirology, is the first to assess the long-term safety and efficacy of bronchial thermoplasty (BT) in patients with severe asthma.

The team compared five-year outcomes for 51 patients (mean age 59) who underwent BT before 2018, including lung function measures, exacerbation frequency, medication use, and asthma control.

Overall, 11 out of 27 patients (41%) requiring maintenance oral steroids at baseline had been completely weaned off at six months post-BT “and remained so for the next five years”.

There was also a 75% reduction in the frequency of exacerbations requiring steroids, which was a greater drop than that seen in previous studies for milder disease, but there was no significant change in spirometry from baseline.

“This finding suggests that it is the more severely affected patients who have the most to gain from BT,” the authors said.

All but eight patients returned improved Asthma Control Questionnaire scores at follow-up, with similar results seen when accounting for nearly half of patients who commenced monoclonal antibody therapy after BT.

High-resolution CT scans showed evidence of minor localised radiological bronchiectasis in about half of the cohort, but none exhibited clinical features of bronchiectasis, such as chronic productive cough or recurrent bacterial infection.

While a longer follow-up may be needed to see signs of disease, the doctors suggested the CT findings could be explained by bronchial dilatation instead.

“In previous studies … we have demonstrated that BT induces bronchial dilatation as part of its mechanism of action,” they wrote.

“We therefore postulate that this is what is being observed by the radiologists reporting these scans, rather than clinical disease.

“However, in reality, we might only know the answer to this question by further follow-up of BT patients, even beyond the 10 years’ data already available.”

They added that the risk of bronchiectasis would need to be weighed against the potential benefits when deciding whether younger patients should receive BT.

“[But] if the procedure is reserved for those patients with frequent exacerbations and high symptom burdens, the equation is likely to be in favour of proceeding with treatment.”

More information: Respirology 2023; 7 Aug.