@article {1674906,
	title = {Relationship between Emphysema Progression at CT and Mortality in Ever-Smokers: Results from the COPDGene and ECLIPSE Cohorts},
	journal = {Radiology},
	volume = {299},
	number = {1},
	year = {2021},
	month = {2021 Apr},
	pages = {222-231},
	abstract = {Background The relationship between emphysema progression and long-term outcomes is unclear. Purpose To determine the relationship between emphysema progression at CT and mortality among participants with emphysema. Materials and Methods In a secondary analysis of two prospective observational studies, COPDGene (clinicaltrials.gov, NCT00608764) and Evaluation of Chronic Obstructive Pulmonary Disease Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE; clinicaltrials.gov, NCT00292552), emphysema was measured at CT at two points by using the volume-adjusted lung density at the 15th percentile of the lung density histogram (hereafter, lung density perc15) method. The association between emphysema progression rate and all-cause mortality was analyzed by using Cox regression adjusted for ethnicity, sex, baseline age, pack-years, and lung density, baseline and change in smoking status, forced expiratory volume in 1 second, and 6-minute walk distance. In COPDGene, respiratory mortality was analyzed by using the Fine and Gray method. Results A total of 5143 participants (2613 men [51\%]; mean age, 60 years {\textpm} 9 [standard deviation]) in COPDGene and 1549 participants (973 men [63\%]; mean age, 62 years {\textpm} 8) in ECLIPSE were evaluated, of which 2097 (40.8\%) and 1179 (76.1\%) had emphysema, respectively. Baseline imaging was performed between January 2008 and December 2010 for COPDGene and January 2006 and August 2007 for ECLIPSE. Follow-up imaging was performed after 5.5 years {\textpm} 0.6 in COPDGene and 3.0 years {\textpm} 0.2 in ECLIPSE, and mortality was assessed over the ensuing 5 years in both. For every 1 g/L per year faster rate of decline in lung density perc15, all-cause mortality increased by 8\% in COPDGene (hazard ratio [HR], 1.08; 95\% CI: 1.01, 1.16; P = .03) and 6\% in ECLIPSE (HR, 1.06; 95\% CI: 1.00, 1.13; P = .045). In COPDGene, respiratory mortality increased by 22\% (HR, 1.22; 95\% CI: 1.13, 1.31; P \< .001) for the same increase in the rate of change in lung density perc15. Conclusion In ever-smokers with emphysema, emphysema progression at CT was associated with increased all-cause and respiratory mortality. {\textcopyright} RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lee and Park in this issue.},
	keywords = {Aged, Clinical Trials as Topic, Disease Progression, Female, Humans, Male, Middle Aged, Pulmonary Emphysema, Smokers, Tomography, X-Ray Computed, United States},
	issn = {1527-1315},
	doi = {10.1148/radiol.2021203531},
	author = {Ash, Samuel Y and San Jos{\'e} Est{\'e}par, Ra{\'u}l and Fain, Sean B and Tal-Singer, Ruth and Stockley, Robert A and Nordenmark, Lars H and Rennard, Stephen and Han, MeiLan K and Merrill, Debora and Humphries, Stephen M and Diaz, Alejandro A and Mason, Stefanie E and Rahaghi, Farbod N and Pistenmaa, Carrie L and Sciurba, Frank C and Vegas-S{\'a}nchez-Ferrero, Gonzalo and Lynch, David A and Washko, George R}
}