Cost-Effectiveness of Follow-Up of Pulmonary Nodules Incidentally Detected on Cardiac CT Angiography in Patients With Suspected Coronary Artery Disease

Study Questions:

Are current guidelines for surveillance imaging of pulmonary nodules incidentally detected on cardiac computed tomography angiography (CCTA) cost-effective?


This study evaluated 3,665 patients referred for CCTA for suspected coronary artery disease at a single center, and used a lung cancer simulation model to estimate the cost-effectiveness of imaging follow-up for pulmonary nodules using the Fleischner guidelines as compared to no imaging follow-up. Patients were excluded if they were <40 years of age, were asymptomatic or presented with acute chest pain, or had previously identified pulmonary nodules.


A pulmonary nodule was identified in 16% (591/3,665) of patients undergoing CCTA. Predicted lifetime detection of lung cancer was 5.8% in the cohort assuming no follow-up, although mortality was dominated by cardiovascular disease (38%) and other causes (57%). Follow-up of pulmonary nodules resulted in a total lifetime detection of lung cancer in 5.9%. Cumulative lifetime lung cancer mortality was reduced in those with versus without follow-up (4.3% vs. 4.5%). This resulted in an improvement in quality-adjusted life expectancy of 0.02 quality-adjusted life-years (QALYs). During a lifetime, patients with follow-up testing had increased costs of $2,200 per person, resulting in an incremental cost-effectiveness ratio of $154,700 per QALY. Among smokers, the incremental cost-effectiveness ratio was $129,800 per QALY.


Adherence to guidelines for follow-up of pulmonary nodules identified on CCTA results in a small decrease in lung cancer mortality, although at a high cost.


Pulmonary nodules are a common issue with CCTA. When multiple surveillance CT scans are recommended, this results in extra costs and radiation exposure, and may result in patient anxiety, as well as downstream biopsies and surgeries. While early detection of lung cancer may improve outcomes, these results suggest it may not be cost-effective in this setting, as it is projected to result in an increase of only 0.02 QALY, and cost $154,700 per QALY (above the threshold of $100,000 per QALY that is generally considered acceptable). It is important to note that these results are derived from simulation models that make several assumptions, are based on data from a single site, and assume complete adherence to the Fleischner guidelines. Nevertheless, these findings raise significant concerns regarding the cost-effectiveness of current guidelines in patients with pulmonary nodules identified on CCTA.

Clinical Topics: Noninvasive Imaging, Atherosclerotic Disease (CAD/PAD)

Keywords: Coronary Artery Disease, Cost-Benefit Analysis, Follow-Up Studies, Chest Pain, Tomography, Biopsy, Lung Neoplasms, Quality-Adjusted Life Years

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