In patients with mild chronic obstructive pulmonary disease (COPD), even a single mucus-plug occluded lung segment was associated with a 48% higher risk of death due to any cause, while having three or more occluded segments nearly doubled the mortality risk, according to a study published in The International Journal of Chronic Obstructive Pulmonary Disease.¹ 

The analysis extracted secondary, unadjusted data from published figures in the COPDGene study. The researchers categorized patients by GOLD stage and recorded mortality rates alongside mucus plug scores. Through this study, they aimed to determine the correlation between the number of mucus plugs occluding the lung segments and mortality risk.

Results showed that for GOLD stage 1 patients, having at least one occluded lung segment increased the risk of all-cause mortality by 48% with hazard ratio (HR) of 1.48 compared to those with no occlusions. The risk was even greater (89%) for those with three or more occluded segments (HR 1.89). In contrast, there was no significant mortality risk for patients with one or two occluded segments or for those in GOLD stages 2 through 4.

The number needed to harm revealed that in GOLD stage 1, 6 patients with three or more occluded segments would result in one additional death, whereas this number was 26 in GOLD stage 4 i.e., 26 patients with ≥3 lung segments occluded by mucus plugs were necessary to report one death.

These findings emphasize the need for timely recognition of mucus plugging in COPD patients, followed by targeted interventions, such as thiol-based mucolytic therapy, to reduce mucus plugs. Assessment of mucus plugs, particularly in patients with chronic mucus hypersecretion, could also serve as a tool for risk stratification in  COPD patients.

Reference

1.   Rogliani P, et al. Impact of airway-occluding mucus plugs on mortality in patients with COPD according to disease severity: a subset analysis of data from COPDGene. Int J Chron Obstruct Pulmon Dis. 2025;20:831-840. https://doi.org/10.2147/COPD.S504065