Treatment for intractable asthma: bronchial thermoplasty

Executive summary: Japanese guidelines for adult asthma (JGL) 2021

Asthma is characterized by chronic airway inflammation, variable airway narrowing, and sensory nerve irritation, which manifest as wheezing, dyspnea, chest tightness, and cough. Longstanding asthma may result in airway remodeling and become intractable. Despite the increased prevalence of asthma in adults, asthma-associated deaths have decreased in Japan (0.94 per 100,000 people in 2020). The goals of asthma treatment include the control of symptoms and reduction of future risks. A functional partnership between physicians and patients is indispensable for achieving these goals. Long-term management with medications and the elimination of triggers and risk factors are fundamental to asthma treatment. Asthma is managed via four steps of pharmacotherapy ("controllers"), ranging from mild to intensive treatments, depending on disease severity; each step involves daily administration of an inhaled corticosteroid, which varies from low to high dosage. Long-acting β₂ agonists, leukotriene receptor antagonists, sustained-release theophylline, and long-acting muscarinic antagonists are recommended as add-on drugs. Allergen immunotherapy is a new option that is employed as a controller treatment. Further, as of 2021, anti-IgE antibody, anti-IL-5 and anti-IL-5 receptor α-chain antibodies, and anti-IL-4 receptor α-chain antibodies are available for the treatment of severe asthma. Bronchial thermoplasty can be performed for asthma treatment, and its long-term efficacy has been reported. Algorithms for their usage have been revised. Comorbidities, such as allergic rhinitis, chronic rhinosinusitis, chronic obstructive pulmonary disease, and aspirin-exacerbated respiratory disease, should also be considered during the treatment of chronic asthma. Depending on the severity of episodes, inhaled short-acting β₂ agonists, systemic corticosteroids, short-acting muscarinic antagonists, oxygen therapy, and other approaches are used as needed ("relievers") during exacerbation.

Cost-effectiveness of bronchial thermoplasty for severe asthmatic patients in Japan

Bronchial thermoplasty (BT) is an interventional endoscopic treatment for severe bronchial asthma. Some studies have shown the clinical efficacy of this intervention, but its cost-effectiveness is unclear. The aim of this study was to evaluate the cost-effectiveness of BT. We collected data from the medical records of 16 Japanese patients who were treated with BT between February 2015 and April 2017, and compared asthma-related medical expenses between the year preceding and the year following BT. Four patients were Global Initiative for Asthma (GINA) treatment step 4, and 12 were step 5. In 8 patients who had a successful response to BT, the annual asthma-related medical expenses decreased because of a reduction in hospitalization and emergency outpatient visits due to asthma attacks, and termination of the use of biologics. Most patients in the non-responder group had increased asthma-related medical costs postoperatively. The main reason for the increase in medical costs was the add-on treatment of biologics. BT was cost-effective in the responder group. If its effects continue for more than 10 years, BT will be a cost-effective treatment. Medical costs will be reduced if those who respond to BT can be identified prior to commencement of treatment.