Association between bronchiectasis exacerbations and longitudinal changes in FEV in patients from the US bronchiectasis and NTM research registry.

Background: This study aimed to evaluate the association between the number of non-cystic fibrosis bronchiectasis (bronchiectasis) exacerbations during baseline and follow-up (objective 1) and to identify longitudinal changes in FEV associated with exacerbation frequency (objective 2).

Methods: This was a retrospective cohort study of adult patients enrolled in the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry September 2008 to March 2020. Objective 1 outcome was association between exacerbations during baseline (24 months) and 0-to-24 month and 24-to-48 month follow-up windows. Objective 2 outcomes were change in FEV and FEV % predicted over 24 months stratified by baseline exacerbation frequency.

Results: Objective 1 cohort (N = 520) baseline frequency of any exacerbations was 59.2%. Overall, 71.4% and 75.0% of patients with ≥1 baseline exacerbations had ≥1 exacerbations during the 0-to-24 and 24-to-48 month follow-ups. Having ≥1 exacerbation during baseline was significantly associated with ≥1 exacerbation during the 0-to-24 month (P = 0.0085) and 24-to-48 month follow-ups (P=<0.0001). Objective 2 cohort (N = 431) baseline FEV was significantly lower in patients who had more exacerbations; however, decline in FEV from baseline was not significantly different between patients with 0, 1, and ≥2 exacerbations. In patients with more baseline exacerbations, FEV % predicted was significantly lower at baseline (P < 0.0001) and at 12 (P = 0.0002) and 24 month follow-ups (P < 0.0001).

Conclusions: Patients with frequent bronchiectasis exacerbations may be more likely than those with less frequent exacerbations to experience disease progression based on future exacerbation frequency and lower FEV at baseline, although FEV decline may not differ by baseline exacerbation frequency.