COPD-associated mucus plugs increase mortality risk: JAMA

A new study by Alejandro Diaz and team showed that the presence of mucus plugs that blocked medium- to large-sized airways on chest computed tomography (CT) images in chronic obstructive pulmonary disease (COPD) participants was linked with increased all-cause mortality compared to those without mucus plugging.The findings of this study were published in the Journal of American Medical Association. 

Airway mucus plugs are prevalent in individuals with chronic obstructive pulmonary disease (COPD); nevertheless, the relationship between airway mucus plugging and mortality in COPD patients remains uncertain. As a result, this study was carried out to see if airway mucus plugs seen on chest computed tomography were related with higher all-cause mortality.

This was an observational retrospective study of prospectively gathered data from COPD patients in the Genetic Epidemiology of COPD cohort. Participants ranged in age from 45 to 80 years old, were non-Hispanic Black or White, and had smoked at least 10 pack-years. Between November 2007 and April 2011, participants were registered at 21 centres around the United States and were followed up on until August 31, 2022. Mucus plugs that totally obstructed airways on chest CT scans, detected in medium- to large-sized airways, and classified as impacting zero, one to two, or three or more lung segments. The primary outcome was all-cause death, which was analysed using proportional hazard regression. 

The key findings of this study were:

The primary analysis comprised 4363 of the 4483 patients with COPD. 

Mucus plugs were found in 0, 1 to 2, and 3 or more lung segments in a total of 2585 (59.3%), 953 (21.8%), and 825 (18.9%) patients, respectively. 

During a 9.5-year median follow-up, 1769 participants (40.6%) died. 

Participants with mucus plugs in 0, 1 to 2, and 3 or more lung segments had death rates of 34.0%, 46.7%, and 54.1%, respectively. 

Mucus plugs in 1 to 2 versus 0 lung segments and 3 or more vs 0 lung segments have been linked with an adjusted hazard ratio of mortality of 1.15 and 1.24, respectively.

Reference: 

Diaz, A. A., Orejas, J. L., Grumley, S., Nath, H. P., Wang, W., Dolliver, W. R., Yen, A., Kligerman, S. J., Jacobs, K., Manapragada, P. P., Abozeed, M., Aziz, M. U., Zahid, M., Han, M. K., … San José Estépar, R. (2023). Airway-Occluding Mucus Plugs and Mortality in Patients With Chronic Obstructive Pulmonary Disease. In JAMA. American Medical Association (AMA). https://doi.org/10.1001/jama.2023.2065