Association Between Airway Mucus Plugs and Risk of Moderate-to-Severe Exacerbations in Patients With COPD: Results From a Chinese Prospective Cohort Study.

Abstract

Airway mucus plugs are frequently identified on CT scans of patients with COPD and are associated with worse airflow obstruction and higher mortality. However, the association between airway mucus plugs and the risk of acute exacerbation of COPD (AECOPD) has not been extensively studied. Are airway mucus plugs associated with the risk of future moderate-to-severe AECOPD? In this prospective cohort study, we identified airway mucus plugs on CT scans of patients with COPD. Mucus plugs were scored from 0 to 18 based on the number of pulmonary segments affected and categorized into 3 groups (0, 1-3, and ≥ 4). Patients were followed for 2 years. Negative binomial regression and Cox regression were used to model the association between airway mucus plugs and moderate-to-severe AECOPD, adjusting for potential confounders. Among the 194 patients with COPD, 22%, 35%, and 43% had mucus plugs in 0, 1 to 3, and ≥ 4 pulmonary segments, respectively. During the following year, 30% of patients experienced at least 1 moderate-to-severe AECOPD, with an incidence of 12%, 25%, and 44% for patients with 0, 1 to 3, and ≥ 4 pulmonary segments with mucus plugs, respectively. In negative binomial regression, each 1-point increase in airway mucus plug score was associated with an 8.3% higher risk of moderate-to-severe exacerbation (incidence rate ratio, 1.08; 95% CI, 1.01-1.16; P = .028). In multivariate Cox regression, mucus plugs in ≥ 4 vs 0 and ≥ 4 vs 1 to 3 pulmonary segments were associated with hazard ratios of moderate-to-severe exacerbation of 5.02 (95% CI, 1.84-13.75; P = .002) and 2.32 (95% CI, 1.25-4.33; P = .008), respectively. Consistent results were observed in the subset of patients completing the 2-year follow-up (n = 150). In patients with COPD, airway mucus plugs were shown to be associated with increased future risk of subsequent moderate-to-severe AECOPD. International Clinical Trials Registry; No.: NCT03240315; URL: https://www.who.int/clinical-trials-registry-platform.