Journal article
Association Between Expiratory Central Airway Collapse and Respiratory Outcomes Among Smokers
JAMA : the journal of the American Medical Association, Vol.315(5), pp.498-505
02/02/2016
DOI: 10.1001/jama.2015.19431
PMCID: PMC5173387
PMID: 26836732
Abstract
Central airway collapse greater than 50% of luminal area during exhalation (expiratory central airway collapse [ECAC]) is associated with cigarette smoking and chronic obstructive pulmonary disease (COPD). However, its prevalence and clinical significance are unknown.
To determine whether ECAC is associated with respiratory morbidity in smokers independent of underlying lung disease.
Analysis of paired inspiratory-expiratory computed tomography images from a large multicenter study (COPDGene) of current and former smokers from 21 clinical centers across the United States. Participants were enrolled from January 2008 to June 2011 and followed up longitudinally until October 2014. Images were initially screened using a quantitative method to detect at least a 30% reduction in minor axis tracheal diameter from inspiration to end-expiration. From this sample of screen-positive scans, cross-sectional area of the trachea was measured manually at 3 predetermined levels (aortic arch, carina, and bronchus intermedius) to confirm ECAC (>50% reduction in cross-sectional area).
Expiratory central airway collapse.
The primary outcome was baseline respiratory quality of life (St George's Respiratory Questionnaire [SGRQ] scale 0 to 100; 100 represents worst health status; minimum clinically important difference [MCID], 4 units). Secondary outcomes were baseline measures of dyspnea (modified Medical Research Council [mMRC] scale 0 to 4; 4 represents worse dyspnea; MCID, 0.7 units), baseline 6-minute walk distance (MCID, 30 m), and exacerbation frequency (events per 100 person-years) on longitudinal follow-up.
The study included 8820 participants with and without COPD (mean age, 59.7 [SD, 6.9] years; 4667 [56.7%] men; 4559 [51.7%] active smokers). The prevalence of ECAC was 5% (443 cases). Patients with ECAC compared with those without ECAC had worse SGRQ scores (30.9 vs 26.5 units; P < .001; absolute difference, 4.4 [95% CI, 2.2-6.6]) and mMRC scale scores (median, 2 [interquartile range [IQR], 0-3]) vs 1 [IQR, 0-3]; P < .001]), but no significant difference in 6-minute walk distance (399 vs 417 m; absolute difference, 18 m [95% CI, 6-30]; P = .30), after adjustment for age, sex, race, body mass index, forced expiratory volume in the first second, pack-years of smoking, and emphysema. On follow-up (median, 4.3 [IQR, 3.2-4.9] years), participants with ECAC had increased frequency of total exacerbations (58 vs 35 events per 100 person-years; incidence rate ratio [IRR], 1.49 [95% CI, 1.29-1.72]; P < .001) and severe exacerbations requiring hospitalization (17 vs 10 events per 100 person-years; IRR, 1.83 [95% CI, 1.51-2.21]; P < .001).
In a cross-sectional analysis of current and former smokers, the presence of ECAC was associated with worse respiratory quality of life. Further studies are needed to assess long-term associations with clinical outcomes.
Details
- Title: Subtitle
- Association Between Expiratory Central Airway Collapse and Respiratory Outcomes Among Smokers
- Creators
- Surya P Bhatt - Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham2UAB Lung Health Center, University of Alabama at Birmingham3UAB Lung Imaging Core, University of Alabama at BirminghamNina L J Terry - UAB Lung Imaging Core, University of Alabama at Birmingham4Department of Radiology, University of Alabama at BirminghamHrudaya Nath - UAB Lung Imaging Core, University of Alabama at Birmingham4Department of Radiology, University of Alabama at BirminghamJordan A Zach - Quantitative Imaging Laboratory, National Jewish Health, Denver, ColoradoJuerg Tschirren - VIDA Diagnostics, Coralville, IowaMark S Bolding - UAB Lung Imaging Core, University of Alabama at Birmingham4Department of Radiology, University of Alabama at BirminghamDouglas S Stinson - Department of Radiology, National Jewish Health, Denver, ColoradoCarla G Wilson - Department of Biostatistics and Bioinformatics, National Jewish Health, Denver, ColoradoDouglas Curran-Everett - Department of Biostatistics and Bioinformatics, National Jewish Health, Denver, ColoradoDavid A Lynch - Quantitative Imaging Laboratory, National Jewish Health, Denver, Colorado7Department of Radiology, National Jewish Health, Denver, ColoradoNirupama Putcha - Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MarylandXavi Soler - Division of Pulmonary, Critical Care and Sleep Medicine, University of California San DiegoRobert A Wise - Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MarylandGeorge R Washko - Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Boston, MassachusettsEric A Hoffman - Department of Radiology and Biomedical Engineering, University of Iowa Carver College of Medicine, Iowa CityMarilyn G Foreman - Division of Pulmonary and Critical Care Medicine, Morehouse School of Medicine, Atlanta, GeorgiaMark T Dransfield - Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham2UAB Lung Health Center, University of Alabama at Birmingham3UAB Lung Imaging Core, University of Alabama at Birmingham14Veterans Affairs Medical Center, Birming
- Resource Type
- Journal article
- Publication Details
- JAMA : the journal of the American Medical Association, Vol.315(5), pp.498-505
- Publisher
- United States
- DOI
- 10.1001/jama.2015.19431
- PMID
- 26836732
- PMCID
- PMC5173387
- ISSN
- 0098-7484
- eISSN
- 1538-3598
- Grant note
- U01 HL089856 / NHLBI NIH HHS R01HL089897 / NHLBI NIH HHS U01 HL089897 / NHLBI NIH HHS R01 HL089856 / NHLBI NIH HHS S10 OD018526 / NIH HHS UL1 TR001417 / NCATS NIH HHS KL2 TR001419 / NCATS NIH HHS R01 HL089897 / NHLBI NIH HHS HL122438 / NHLBI NIH HHS K23 HL123594 / NHLBI NIH HHS P30 CA086862 / NCI NIH HHS R01HL089856 / NHLBI NIH HHS
- Language
- English
- Date published
- 02/02/2016
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Internal Medicine
- Record Identifier
- 9984051985002771
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