Physician-authored summaries and commentary on the most important medical research, provided by the NEJM Group, a division of the Massachusetts Medical Society.
© Massachusetts Medical SocietyApril 2025
Mucus plugs seen on chest CT in patients without evident symptoms were associated with more-severe disease.
Computed tomography (CT) scans often reveal airway mucus plugs in patients with chronic obstructive pulmonary disease (COPD) who do not have mucus-related symptoms. To shed light on the significance of these ‘silent’ mucus plugs, investigators reviewed clinical and imaging data for 4400 participants with COPD.
Among the 1700 patients who had no cough or phlegm, those whose CT scans showed mucus plugs had significantly worse clinical measures (e.g. shorter six-minute walk distance, lower resting arterial oxygen saturation, lower percentage of predicted forced expiratory volume in 1 second, more emphysema and higher odds of severe exacerbations in the past year) than those without mucus plugs. Comparisons were adjusted for potential confounders, including age, body mass index and smoking status.
Comment: I often rely on CT imaging in my patients with COPD to help define the degree of emphysema and look for concomitant conditions (e.g. pulmonary nodules, lung cancer, coronary artery calcification) but have not always considered mucus plugs to be of prognostic significance. As discussed in a recent review of incidental findings on chest CT (NEJM JW Gen Med Oct 15 2024 and Am J Respir Crit Care Med 2024; 210: 281-287), the finding of mucus plugs in patients with COPD who do not report symptoms of chronic bronchitis identifies patients who have more severe disease and worse prognosis. As a clinician, I tend to focus on patients with symptoms. This article reinforces that mucus plugs in patients without symptoms are an important and ominous sign.
Steven T. Kariya, MD, Clinical Professor of Medicine, George Washington University School of Medicine, Washington, DC; Pulmonologist, Privia Health, Kensington, USA.
Mettler SK, et al. Silent airway mucus plugs in COPD and clinical implications. Chest 2024; 166: 1010-1019.
This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine, Hospital Medicine.