Abstract
Background. Extracranial internal carotid artery stenosis (50%-99% arterial narrowing) is an important risk factor for ischemic stroke. Yet, the benefits and harms of targeted screening for asymptomatic carotid artery stenosis (ACAS) have not been assessed in population-based studies. We aimed to estimate the cost-effectiveness of one-time, targeted ACAS screening stratified by atherosclerotic cardiovascular disease (ASCVD) risk using the American Heart Association's pooled cohort equations. Methods. We developed a lifetime microsimulation model of ACAS and stroke for a hypothetical cohort representative of US adults aged 50 to 80 y without stroke history. Model parameters were derived from multiple cohort studies and the published literature. Outcomes included estimated stroke events prevented, lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) associated with ACAS screening. Costs (2023 USD) and QALYs were discounted at 3% annually. Cost-effectiveness was assessed from the health care sector perspective using a $100,000/QALY threshold. Results. We found that screening individuals with a 10-y ASCVD risk >30% was the most cost-effective strategy, with an ICER of $89,000/QALY. This strategy would make approximately 11.9% of the population eligible for screening, averting an estimated 24,084 strokes over the cohort's lifetime. In probabilistic sensitivity analysis, screening those in lower ASCVD risk groups (0%-20%) had only a 0.6% chance of being cost-effective. If the ongoing CREST-2 trial shows that revascularization reduces stroke risk by less than 30% (relative risk >0.7), it may shift the balance against any screening. Conclusions. ACAS screening may be cost-effective only for adults at relatively high ASCVD risk. These findings provide a flexible decision-analytic framework that can inform clinical and policy guidance as future trial results refine the role of revascularization and intensive medical therapy. HIGHLIGHTS: Targeted screening for asymptomatic carotid artery stenosis may be cost-effective only for adults aged 50 to 80 y at high atherosclerotic cardiovascular disease (ASCVD) risk.Screening individuals with a 10-y ASCVD risk greater than 30% could substantially reduce lifetime stroke burden while remaining within accepted US cost-effectiveness thresholds.Screening lower-risk (0%-20% 10-y ASCVD risk) adults provides minimal health gains at significantly higher costs and should not be recommended.Findings offer a decision-analytic framework to inform future screening guidelines and policy decisions as results from ongoing trials, such as CREST-2, become available.