Emphysema detected on baseline low-dose computed tomography predicted long-term mortality outcomes in a large lung cancer screening cohort. Researchers followed 9,047 patients for up to 25 years and found that emphysema was linked with increased deaths from all causes, chronic obstructive pulmonary disease, and cardiovascular disease.
At baseline, emphysema was present in 29% of patients. Of these, 21% had mild emphysema, 6% had moderate, and 2% had severe. Median follow-up was 23 years. Patients with emphysema had higher mortality compared with those without emphysema. Hazard ratios were 1.29 for all-cause mortality, 3.29 for chronic obstructive pulmonary disease (COPD) mortality, and 1.14 for cardiovascular disease (CVD) mortality, wrote lead study researcher Jessica González Gutiérrez, PhD, of IRBLleida, Spain, and colleagues.
Severity of emphysema was associated with progressively higher risk for all-cause and COPD deaths. Patients with severe emphysema had more than a 12-fold higher risk of COPD mortality compared with those without emphysema. The graded association was not observed for CVD deaths.
Notably, 2,063 patients (79%) with baseline emphysema had no prior known diagnosis of emphysema or COPD, even though 103 patients (5%) had moderate or severe emphysema. This suggests emphysema should not be considered merely an incidental CT finding but rather a distinct disease entity associated with increased mortality risk.
The study included asymptomatic patients aged 40 to 85 years with current or past cigarette use. Enrollment occurred from 2000 to 2008 at 12 institutions in New York. Median age was 65 years, and patients reported a median smoking history of 43 pack-years. By December 2024, 3,738 participants (41%) had died, most commonly from CVD (1,153 deaths; 13%), followed by COPD (295 deaths; 3%).
Baseline CT scans were reviewed by four experienced chest radiologists using a standardized emphysema scoring system. Emphysema was categorized as none, mild, moderate, or severe. Mortality outcomes were determined through the National Death Index and verified with additional records. Researchers used Cox proportional hazards models, Kaplan–Meier survival analyses, and Fine–Gray competing-risks models to analyze outcomes.
The researchers noted several limitations, including the subjective nature of visual emphysema assessment, varying scan parameters over the 25-year enrollment period, and lack of automated quantification tools. Changes in smoking habits, comorbidities, or treatments over time were not captured.
Full disclosures can be found in the published study.
Source: Radiology
