Abstract
Background The prognostic value of baseline visual emphysema scoring at low-dose CT (LDCT) in lung cancer screening cohorts is unknown. Purpose To determine whether a single visual emphysema score at LDCT is predictive of 25-year mortality from all causes, chronic obstructive pulmonary disease (COPD), and cardiovascular disease (CVD). Materials and Methods In this prospective cohort study, asymptomatic adults aged 40-85 years with a history of smoking underwent baseline LDCT screening for lung cancer between June 2000 and December 2008. Follow-up continued until death, loss to follow-up, or December 31, 2024. Emphysema was assessed at baseline LDCT and scored from 0 (none) to 3 (severe) by one of four experienced chest radiologists. Baseline smoking history and comorbidities were self-reported. Causes of death (International Classification of Diseases, 10th Revision) were obtained from the U.S. National Death Index, physicians, and family. Associations between emphysema and mortality were evaluated using adjusted Cox proportional hazards and adjusted Fine-Gray competing risks models. Results Among 9047 participants (4614 female; median age, 65 years [IQR, 61-69 years]; median pack-years of smoking, 43 [IQR, 28-64]), 2637 (29.1%) had emphysema (mild in 1908 [21.1%], moderate in 512 [5.7%], and severe in 217 [2.4%]). Median follow-up was 23.3 years. Emphysema was independently predictive of all-cause mortality (hazard ratio [HR], 1.29; 95% CI: 1.21, 1.38; P < .001), COPD mortality (HR, 3.29; 95% CI: 2.59, 4.18; P < .001), and CVD mortality (HR, 1.14; 95% CI: 1.01, 1.29; P = .04). A dose-response relationship was observed between emphysema severity and both all-cause and COPD mortality, but not CVD mortality. In the adjusted competing risk analysis, emphysema remained associated with COPD mortality (HR, 3.06; 95% CI: 2.40, 3.90; P < .001), but not CVD mortality (HR, 1.04; 95% CI: 0.91, 1.18; P = .59). Conclusion Baseline emphysema at LDCT in a prospective lung cancer screening cohort of asymptomatic adults was predictive of all-cause, COPD, and CVD mortality up to 25 years later. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Mascalchi and Diciotti in this issue.