Use of inhaled corticosteroids in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC)

Introduction: Current bronchiectasis guidelines advise against the use of inhaled corticosteroids (ICS) except in patients with associated asthma, allergic bronchopulmonary aspergillosis (ABPA) and/or chronic obstructive pulmonary disease (COPD). This study aimed to describe the use of ICS in patients with bronchiectasis across Europe. Methods: Patients with bronchiectasis were enrolled into the European Bronchiectasis Registry from 2015 to 2022. Patients were grouped into ICS users and non-users at baseline and clinical characteristics associated with ICS use were investigated. Patients were followed up for clinical outcomes of exacerbation, hospitalisation and mortality for up to 5 years. We evaluated if elevated blood eosinophil counts (above the laboratory upper limit of normal) modified the effect of ICS on exacerbations. Results: 19 324 patients were included for analysis and 10 109 (52.3%) were recorded as being prescribed ICS at baseline. After exclusion of patients with a history of asthma, COPD and/or ABPA, 3174/9715 (32.7%) patients with bronchiectasis were prescribed ICS. Frequency of ICS use varied across countries, ranging from 17% to 85% of included patients. ICS users had more severe disease, with significantly worse lung function, higher Bronchiectasis Severity Index scores and more frequent exacerbations at baseline (p<0.0001). Overall, ICS users did not have a reduced risk of exacerbation or hospitalisation during follow-up, but a significant reduction in exacerbation frequency was observed in the subgroup of ICS users with elevated blood eosinophil counts (relative risk 0.70, 95% CI 0.59 to 0.84, p<0.001). Conclusion: ICS use is common in bronchiectasis, including in those not currently recommended ICS according to bronchiectasis guidelines. ICS use may be associated with reduced exacerbation frequency in patients with elevated blood eosinophils.