Reduced Total Airway Count and Airway Wall Tapering after Three-Years in Ex-Smokers

Paulina V Wyszkiewicz; Maksym Sharma; Vedanth Desaigoudar; Ian A Cunningham; David G McCormack; Mohamed A Abdelrazek; Miranda Kirby; Grace Parraga

doi:10.1080/15412555.2023.2222831

Reduced Total Airway Count and Airway Wall Tapering after Three-Years in Ex-Smokers

COPD. 2023 Dec;20(1):186-196. doi: 10.1080/15412555.2023.2222831.

Authors

Paulina V Wyszkiewicz^{1

2}, Maksym Sharma^{1

2}, Vedanth Desaigoudar^{1

2}, Ian A Cunningham^{1

2

3

4}, David G McCormack⁵, Mohamed A Abdelrazek³, Miranda Kirby⁶, Grace Parraga^{1

2

4

5}

Affiliations

¹ Robarts Research Institute, Western University, London, Ontario, Canada.
² Department of Medical Biophysics, Western University, London, Ontario, Canada.
³ Department of Medical Imaging, Western University, London, Ontario, Canada.
⁴ School of Biomedical Engineering, Western University, London, Ontario, Canada.
⁵ Division of Respirology, Department of Medicine, Western University, London, Ontario, Canada.
⁶ Department of Physics, Toronto Metropolitan University, Toronto, Ontario, Canada.

PMID: 37395048
DOI: 10.1080/15412555.2023.2222831

Abstract

Computed tomography (CT) total-airway-count (TAC) and airway wall-thickness differ across chronic obstructive pulmonary disease (COPD) severities, but longitudinal insights are lacking. The aim of this study was to evaluate longitudinal CT airway measurements over three-years in ex-smokers. In this prospective convenience sample study, ex-smokers with (n = 50; 13 female; age = 70 ± 9 years; pack-years = 43 ± 26) and without (n = 40; 17 female; age = 69 ± 10 years; pack-years = 31 ± 17) COPD completed CT, ³He magnetic resonance imaging (MRI), and pulmonary function tests at baseline and three-year follow-up. CT TAC, airway wall-area (WA), lumen-area (LA), and wall-area percent (WA%) were generated. Emphysema was quantified as the relative-area-of-the-lung with attenuation < -950 Hounsfield-units (RA₉₅₀). MRI ventilation-defect-percent (VDP) was also quantified. Differences over time were evaluated using paired-samples t tests. Multivariable prediction models using the backwards approach were generated. After three-years, forced-expiratory-volume in 1-second (FEV₁) was not different in ex-smokers with (p = 0.4) and without (p = 0.5) COPD, whereas RA₉₅₀ was (p < 0.001, p = 0.02, respectively). In ex-smokers without COPD, there was no change in TAC (p = 0.2); however, LA (p = 0.009) and WA% (p = 0.01) were significantly different. In ex-smokers with COPD, TAC (p < 0.001), WA (p = 0.04), LA (p < 0.001), and WA% (p < 0.001) were significantly different. In all ex-smokers, TAC was related to VDP (baseline: ρ = -0.30, p = 0.005; follow-up: ρ = -0.33, p = 0.002). In significant multivariable models, baseline airway wall-thickness was predictive of TAC worsening. After three-years, in the absence of FEV₁ worsening, TAC diminished only in ex-smokers with COPD and airway walls were thinner in all ex-smokers. These longitudinal findings suggest that the evaluation of CT airway remodeling may be a useful clinical tool for predicting disease progression and managing COPD.Clinical trial registration: www.clinicaltrials.gov NCT02279329.

Keywords: Chronic obstructive pulmonary disease; airways disease; computed tomography; disease progression; ex-smokers; longitudinal measurements.

Publication types

Clinical Trial
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Ex-Smokers
Female
Humans
Lung / diagnostic imaging
Middle Aged
Prospective Studies
Pulmonary Disease, Chronic Obstructive* / diagnostic imaging
Pulmonary Emphysema* / diagnostic imaging

Associated data

ClinicalTrials.gov/NCT02279329

Grants and funding

CIHR/Canada