Bronchiectasis and asthma: Data from the European Bronchiectasis Registry (EMBARC)

Abstract

BackgroundAsthma is commonly reported in patients with a diagnosis of bronchiectasis. ObjectiveThe aim of this study was to evaluate if patients with asthma and bronchiectasis had a different clinical phenotype and different outcomes compared to patients with bronchiectasis without concomitant asthma. MethodsProspective observational pan-European registry (EMBARC) enrolling patients across 28 countries. Adult patients with CT confirmed bronchiectasis were reviewed at baseline and annual follow-up visits using an electronic case report form. Asthma was diagnosed by the local investigator. Follow-up data were used to explore differences in exacerbation frequency between groups using a negative binomial regression model. Survival analysis utilised Cox-proportional hazards regression. Results16963 patients with bronchiectasis were included for analysis. 5267 patients (31.0%) had investigator reported asthma. Patients with bronchiectasis and asthma (BE+A) were younger, more likely to be female and never smokers, and had a higher BMI than patients with bronchiectasis without asthma. BE+A was associated with a higher prevalence of rhinosinusitis and nasal polyps as well as eosinophilia and Aspergillus sensitization. BE+A had similar microbiology, but significantly lower severity of disease using the bronchiectasis severity index (BSI). The BE+A group were at increased risk of exacerbation after adjustment for severity of disease and multiple confounders. Inhaled corticosteroid use was associated with reduced mortality in BE+A patients (adjusted hazard ratio 0.78 (0.63-0.95)) and reduced risk of hospitalization, (rate ratio 0.67 (0.67-0.86)) compared to a control population without asthma and not receiving inhaled corticosteroid. ConclusionCombined bronchiectasis and asthma was common and was associated with an increased risk of exacerbations and improved outcomes with inhaled corticosteroid use. Unexpectedly we identified significantly lower mortality in patients with bronchiectasis and asthma.