Longitudinal Imaging-Based Clusters in Former Smokers of the COPD Cohort Associate with Clinical Characteristics: The SubPopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS)

• Published in: International journal of chronic obstructive pulmonary disease Vol. 16; pp. 1477 - 1496
• Main Authors: Zou, Chunrui, Li, Frank, Choi, Jiwoong, Haghighi, Babak, Choi, Sanghun, Rajaraman, Prathish K, Comellas, Alejandro P, Newell, John D, Lee, Chang Hyun, Barr, R Graham, Bleecker, Eugene, Cooper, Christopher B, Couper, David, Han, Meilan, Hansel, Nadia N, Kanner, Richard E, Kazerooni, Ella A, Kleerup, Eric C, Martinez, Fernando J, O'Neal, Wanda, Paine, 3rd, Robert, Rennard, Stephen I, Smith, Benjamin M, Woodruff, Prescott G, Hoffman, Eirc A, Lin, Ching-Long
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01.01.2021; Dove Medical Press Ltd; Dove; Dove Medical Press
• Subjects: Chronic obstructive pulmonary disease; Cluster analysis; computed tomography; Cross-Sectional Studies; CT imaging; Diagnostic imaging; Emphysema; functional small airway disease; Humans; longitudinal clustering; Lung diseases, Obstructive; Medical imaging; Original Research; Outcome Assessment, Health Care; Pharmaceutical industry; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Emphysema - diagnostic imaging; Radiation; Smokers; Spirometry; France; United States; United Kingdom; computed tomography; functional small airway disease; longitudinal clustering; emphysema
• ISSN: 1178-2005; 1176-9106; 1178-2005
• DOI: 10.2147/COPD.S301466

Quantitative computed tomography (qCT) imaging-based cluster analysis identified clinically meaningful COPD former-smoker subgroups (clusters) based on cross-sectional data. We aimed to identify progression clusters for former smokers using longitudinal data. We selected 472 former smokers from SPIROMICS with a baseline visit and a one-year follow-up visit. A total of 150 qCT imaging-based variables, comprising 75 variables at baseline and their corresponding progression rates, were derived from the respective inspiration and expiration scans of the two visits. The COPD progression clusters identified were then associated with subject demography, clinical variables and biomarkers. COPD severities at baseline increased with increasing cluster number. Cluster 1 patients were an obese subgroup with rapid progression of functional small airway disease percentage (fSAD%) and emphysema percentage (Emph%). Cluster 2 exhibited a decrease of fSAD% and Emph%, an increase of tissue fraction at total lung capacity and airway narrowing over one year. Cluster 3 showed rapid expansion of Emph% and an attenuation of fSAD%. Cluster 4 demonstrated severe emphysema and fSAD and significant structural alterations at baseline with rapid progression of fSAD% over one year. Subjects with different progression patterns in the same cross-sectional cluster were identified by longitudinal clustering. qCT imaging-based metrics at two visits for former smokers allow for the derivation of four statistically stable clusters associated with unique progression patterns and clinical characteristics. Use of baseline variables and their progression rates enables identification of longitudinal clusters, resulting in a refinement of cross-sectional clusters.