Cost-effectiveness of novel imaging tests to select patients for carotid endarterectomy

Objective: We estimated the cost-effectiveness of novel imaging tests to select patients for carotid endarterectomy (CEA) in patients with significant carotid stenosis using a computer model and explored the minimum prognostic performance that a new confirmatory test must have in order to be cost-effective versus the guideline-based strategy.
Methods: The guidelines recommend initial duplex ultrasonography (DUS) followed by a confirmatory test if DUS shows 30–69% stenosis; a positive CT-angiography (CTA) is an indication for CEA. In an alternative strategy, we replaced CTA with CE-DUS, and in another strategy we replaced it by a hypothetical imaging test and estimated the minimum prognostic performance that the test must have in order to be cost-effective versus the guideline-based strategy. We assessed the potential cost-effectiveness in four age- and sex-specific subpopulations.
Results: For 60-year-old men, a perfect confirmatory test (100% sensitivity and specificity) improves health (0.066 quality-adjusted life years) and reduces costs ( €110/$146) versus the guideline-based strategy. Potential health gain is smaller for 80-year-old men, while no health gain is expected for women. Assuming 100% sensitivity, a test must have a specificity of at least 66% for 60-year-old men and 87% for 80-year-old men to be cost-effective. Similarly, assuming 100% specificity, a test must have a sensitivity of at least 58% for 60-year-old men and 66% for 80-year-old men.
Conclusions: Information from new imaging technologies may improve stroke risk prediction and thereby improve decisions about which patients should undergo CEA. However, their cost-effectiveness strongly depends on the current test strategy and choice of patient subpopulation.