The effect of maintenance azithromycin on radiological features in patients with bronchiectasis - Analysis from the BAT randomized controlled trial

Rationale Bronchiectasis (abnormal dilatation of bronchi) is usually diagnosed by high resolution computed tomography (HRCT) and radiological severity has been found to correspond with clinical outcome. A beneficial effect of macrolides maintenance treatment in frequent exacerbating bronchiectasis patients has been established in randomized trials.This study was undertaken to prospectively evaluate the effect of long-term azithromycin (AZM) on radiological features in patients with bronchiectasis. Methods The BAT randomized controlled trial (2008–2010) investigated the effect of 1 year of AZM (250 mg OD) in bronchiectasis with frequent exacerbations. Chest (HR)CT-scans at baseline and after one year of study treatment were obtained and scored by two radiologists according to the Brody - and the Bhalla scoring system. Results 77 (93%) patients conducted the BAT trial were evaluated in this post-hoc analysis. A significant improvement of the radiological features based on the Brody score was found after one year of AZM therapy as compared to placebo (p = 0.024), with a not significant improvement of the Bhalla score (p=0.071). Especially the consolidation (Bhalla) and parenchymal changes (Brody) sub scores significantly improved (both p=0.030), and even a radiological deterioration was seen on the Brody bronchiectasis sub score for the placebo treated patients (mean 14.5 (11.7) vs.15.7 (11.9)). Conclusions The beneficial effect of long-term AZM treatment on radiological features was demonstrated in this randomized controlled trial. (HR)CT's can be used as an objective measure of treatment response in bronchiectasis. Clinical trial registration number NCT00415350