Abstract Rationale Expiratory central airway collapse (ECAC) may represent a promising clinical subtype of chronic obstructive pulmonary disease (COPD), however, evidence regarding the clinical significance of ECAC in COPD remains limited. Whether the presence of ECAC is associated with worse respiratory health outcomes among patients with COPD? Methods This study included patients with COPD from a prospective, population-based cohort study in China. Participants underwent spirometry, questionnaires, and paired inspiratory and expiratory chest computed tomography at baseline and completed spirometry and questionnaires annually during the 3-year follow-up. ECAC was defined as a reduction in airway cross-sectional area of ≥ 50% during end-expiration compared with end-inspiration at any of the following three anatomical levels: the aortic arch, the carina, and the bronchus intermedius. The outcomes of this study were the risk of exacerbations and the annual rate of lung function decline. Sensitivity analyses were conducted to examine the associations of ECAC at each individual anatomical level and the number of collapsed anatomical levels with clinical outcomes. Results A total of 915 patients with COPD were included in the baseline analysis, 892 patients completed follow-up for exacerbation assessment, and 865 for assessing annual lung function decline. The detection rate of ECAC among patients with COPD was 8.7% (80/915). Compared with patients without ECAC, those with ECAC had a higher BMI and worse lung function. Patients with ECAC had a higher total exacerbation (RR = 1.50, 95% confidence interval CI: 1.11-2.04, P = 0.009) and moderate-to-severe exacerbation (RR = 1.49, 95%CI: 1.07-2.09, P = 0.017) than those without ECAC. Analysis at individual anatomical levels revealed that ECAC was significantly associated with an increased risk of total and moderate-to-severe exacerbations. With each additional anatomical level of ECAC, the risk of total exacerbations (RR = 1.22, 95%CI: 1.06-1.41, P = 0.006) and moderate-to-severe exacerbations (RR = 1.18, 95%CI: 1.01-1.39, P = 0.043) increased. No statistically significant difference was found in lung function decline between patients with ECAC and those without. Conclusions The results of this study demonstrated that ECAC was associated with a higher risk of exacerbations among patients with COPD, suggesting that ECAC may serve as a clinical subtype for guiding future exacerbation risk assessment. This abstract is funded by: Guangzhou National Laboratory (SRPG22-016 and SRPG22-018), the National Natural Science Foundation of China (82570065), the Clinical and Epidemiological Research Project of State Key Laboratory of Respiratory Disease (SKLRD-L-202402), and the Plan on Enhancing Scientific Research in Guangzhou Medical University (GMUCR2024-01012)
Wu et al. (Fri,) studied this question.