Mucous plugs linked to COPD mortality

Attendees with chronic obstructive pulmonary disease (COPD) According to a study published in JAMA. ¹

Airway mucus plugging is common in patients with COPD, but the association between airway mucus plugging and mortality in COPD patients was not known.

“Chronic Obstructive Pulmonary Disease (COPD) affects 15.9 million people in the United States and is the fourth leading cause of death. Mucus dysfunction, a central pathology in patients with COPD, is characterized by excessive mucus production, hypersecretion and reduced clearance, leading to airway accumulation in the form of plugs,” the researchers said.

First, the researchers tried to determine whether airway mucus plugs recognized on CT scans were associated with increased all-cause mortality.

Next, prospective data from patients with a diagnosis of COPD in the COPD Genetic Epidemiology Cohort were collected in a retrospective observational analysis. Participants were non-Hispanic black or white people, ages 45 to 80, who had smoked at least 10 pack-years. Participants were enrolled at 21 centers across the United States between November 2007 and April 2011, and were followed through August 31, 2022.

Mucous plugs that completely blocked the airway on chest CT scans, found in medium to large airways (approximately 2–10 mm lumen diameter), were classified as affecting 0, 1–2, or 3 segments lungs or more.

Next, the researchers identified the primary outcome as all-cause mortality, assessed with proportional hazard regression analysis. Model adjustments were made for age, sex, race and ethnicity, body mass index, years of pack smoked, current smoking status, forced expiratory volume in the first second of expiration and CT measurements of emphysema and airway disease.

Of the 4483 participants with COPD, 4363 were included in the primary analysis (median age, 63 years [IQR, 57-70 years]; 44% were women). A total of 2585 (59.3%), 953 (21.8%) and 825 (18.9%) participants had mucus plugs in 0, 1 to 2 and 3 or more lung segments, respectively.

During a median follow-up of 9.5 years, 1769 participants (40.6%) died. The mortality rates were 34.0% (95% CI, 32.2%-35.8%), 46.7% (95% CI, 43.5%-49.9%) and 54. 1% (95% CI, 50.7%-57.4%) in participants who had 0, 1 to 2, and 3 or more mouth mucus respectively.

The existence of mucus plugs in 1 to 2 vs 0 and 3 or more vs 0 lung segments was associated with an adjusted RR of death of 1.15 (95% CI, 1.02-1.29) and 1.24 (95% CI, 1.10-1.41), respectively.

Corresponding author Alejandro A. Diaz, MD, MPH, a research associate in the Division of Pulmonary and Critical Care Medicine at Brigham and Women’s Hospital, said in a Press release“As a chronic disease, COPD cannot be cured, but our results suggest that using therapies to break up these mucous plugs could help improve outcomes for patients with COPD, which is the next best thing to TO DO.”²

Mucous plugs blocking multiple bronchi could increase the risk of pneumonia and the risk of exacerbation of COPD.

“Furthermore, the presence of mucous plugs is associated with ventilation/perfusion mismatch, which can lead to respiratory failure, a common cause of death in COPD,” the researchers continued.

The results of the study and those of previous studies could generate hypotheses for testing clinical interventions targeting mucous plugs in COPD that could provide a treatment target for healthcare providers. Preliminary studies in asthma suggest that biologic treatment decreases mucous plugs on CT and that reduction in mucous plugs was associated with improved lung function.

One of the limitations of this study was that it was observational, so it is impossible to draw conclusions that mucosal plugging causes death. Second, the COPDGene cohort only enrolled non-Hispanic black and non-Hispanic white participants, so the results might not apply to other racial and ethnic groups that were not included.

“The fact that these mucous plugs are associated with mortality at different stages of the disease tells us that there are aspects of COPD progression that can be detected by a CT scan even though they are not felt by the patient. “, Diaz concluded in the press release. .

The references

1. Diaz AA, Orejas JL, Grumley S, et al. Airway obstructing mucus plugs and mortality in patients with chronic obstructive pulmonary disease. JAMA. Published online May 21, 2023. doi: 10.1001/jama.2023.2065

2. A study linking mucous plugs to COPD mortality could help save lives. Eurekalert! May 21, 2023. Accessed June 5, 2023. https://www.eurekalert.org/news-releases/989777