Cost Effectiveness of Assessing Ultrasound Plaque Characteristics to Risk Stratify Asymptomatic Patients With Carotid Stenosis

Abstract

Background Imaging may play an important role in identifying high‐risk plaques in patients who have carotid disease and who could benefit from surgical revascularization. We sought to evaluate the cost effectiveness of a decision‐making rule based on the ultrasound imaging assessment of plaque echolucency in patients with asymptomatic carotid stenosis. Methods and Results We used a decision‐analytic model to project lifetime quality‐adjusted life years and costs for 5 stroke prevention strategies: (1) medical therapy only; (2) revascularization if both plaque echolucency and stenosis progression to >90% are present; (3) revascularization only if plaque echolucency is present; (4) revascularization only if stenosis progression >90% is present; or (5) either plaque echolucency or stenosis progression is present. Risks of clinical events, costs, and quality‐of‐life values were estimated based on published sources and the analysis was conducted from a healthcare system perspective for asymptomatic patients with 70% to 89% carotid stenosis at presentation. Patients who did not undergo revascularization had the highest stroke events (17.6%) and lowest life‐years (8.45), while those who underwent revascularization on the basis of either presence of plaque echolucency on ultrasound or progression of carotid stenosis had the lowest stroke events (12.0%) and longest life‐years (14.41). The either plaque echolucency or progression‐based revascularization group had an incremental cost‐effectiveness ratio of $110 000/quality‐adjusted life years compared with the plaque echolucency‐based strategy, which had an incremental cost‐effectiveness ratio of $29 000/quality‐adjusted life years compared with the joint echolucency and progression‐based strategy. Conclusions Plaque echolucency on ultrasound can be a cost‐effective tool to identify patients with asymptomatic carotid artery stenosis most likely to benefit from carotid endarterectomy.