Mixed Mucus Plug-Emphysema Subtype and Acute Exacerbation in Chronic Obstructive Pulmonary Disease.

Abstract

Conventional clinical assessments inadequately capture chronic obstructive pulmonary disease (COPD) heterogeneity. Quantitative computed tomography metrics may enable refined phenotyping and improved prognostic assessment. What is the prognostic value of quantitative computed tomography-derived mucus plugs and emphysema for acute exacerbations in COPD? This prospective cohort study collected clinical data, chest computed tomography, and pulmonary function tests from patients with COPD. Patients were stratified by mucus plug score (cutoff: 4) and emphysema severity (%LAA-950 cutoff: 5%). Multivariate logistic regression analysis was performed to assess the association between subgroups and acute exacerbations. Stratified analysis was employed to evaluate both independent and combined effects. A total of 215 patients were categorized into four subgroups: low mucus/low emphysema (n=61), low mucus/high emphysema (n=46), high mucus/low emphysema (n=62), and high mucus/high emphysema (n=46). Compared with the low mucus/low emphysema group, the risk of acute exacerbation increased progressively across the other three subgroups, with adjusted ORs of 2.885 (95%CI:1.060-8.166, P=0.041), 3.134 (95%CI:1.212-8.540, P=0.021), and 3.297 (95%CI:1.096-10.298, P=0.036). Additionally, each 1-point increase in the mucus plug score was associated with a 1.1-fold higher risk of acute exacerbation (OR 1.111, 95%CI: 1.005-1.232, P=0.041). The association between higher mucus plugs (≥4 vs. <4) and acute exacerbations was statistically significant only in the low emphysema subgroup (OR 3.318, 95%CI: 1.114-10.731, P=0.036). Quantitative computed tomography-defined mucus plugs and emphysema jointly identify clinically meaningful COPD subgroups and predict exacerbations, supporting their use for personalized risk stratification and targeted prevention.