Favorable Response to Long-Term Azithromycin Therapy in Bronchiectasis Patients with Chronic Airflow Obstruction Compared to Chronic Obstructive Pulmonary Disease Patients without Bronchiectasis

Purpose: Long-term macrolide treatment is recommended for patients with chronic obstructive pulmonary disease (COPD) with frequent exacerbations. Bronchiectasis is a common comorbid condition in patients with COPD, for which long-term azithromycin is effective in preventing exacerbation. This study aimed to compare the effect of long-term azithromycin between bronchiectasis patients with chronic airflow obstruction (CAO) and COPD patients without bronchiectasis. Patients and Methods: Patients with CAO who received azithromycin for more than 12 weeks were retrospectively identified at a single referral hospital. CAO was defined as a post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <0.7, and bronchiectasis was determined using computed tomography. The development of exacerbation and symptom improvement were compared between bronchiectasis patients with CAO and COPD patients without bronchiectasis. Results: A total of 59 patients (43 in bronchiectasis with CAO group vs 16 in COPD without bronchiectasis group) were included in this study. Compared to COPD patients without bronchiectasis, those in bronchiectasis with CAO group were younger, more likely to be female, and never smokers. There was no difference in the previous exacerbation history or FEV1 between the two groups. The median duration of azithromycin treatment was 15 months (interquartile range, 8-25 months). At the 12-month follow-up, the development of >= 2 moderate or >= 1 severe exacerbations was significantly lower in bronchiectasis with CAO group than in COPD without bronchiectasis group (46.5% vs 87.5%, P = 0.005). The proportion of patients with symptom improvement determined by the COPD assessment test score was also significantly higher in bronchiectasis with CAO group than COPD without bronchiectasis group at the 12-month follow-up (68.2% vs 16.7%, P = 0.004). Conclusion: Bronchiectasis patients with CAO could benefit more from long-term azithromycin treatment than COPD patients without bronchiectasis.