Carotid stiffness indicates risk of ischemic stroke and TIA in patients with internal carotid artery stenosis - The SMART study

Background and Purpose - Patients with a carotid artery stenosis, including those with an asymptomatic or moderate stenosis, have a considerable risk of ischemic stroke. Identification of risk factors for cerebrovascular disease in these patients may improve risk profiling and guide new treatment strategies. We cross-sectionally investigated whether carotid stiffness is associated with previous ischemic stroke or transient ischemic attack (TIA) in patients with a carotid artery stenosis of at least 50%. Methods - Patients were selected from the Second Manifestations of ARTerial disease ( SMART) study, a cohort study among patients with manifest vascular disease or vascular risk factors. Arterial stiffness, measured as change in lumen diameter of the common carotid arteries during the cardiac cycle, forms part of the vascular screening performed at baseline. The first 420 participants with a stenosis of minimally 50% in at least 1 of the internal carotid arteries measured by duplex scanning were included in this study. Logistic regression analysis was used to determine the relation between arterial stiffness and previous ischemic stroke or TIA. Results - The risk of ischemic stroke or TIA in the highest quartile ( stiffest arteries) relative to the lowest quartile was 2.1 (95% CI, 1.1 to 4.1). These findings were adjusted for age, sex, systolic blood pressure, minimal diameter of the carotid artery, and degree of carotid artery stenosis. Conclusion - In patients with a greater than or equal to 50% carotid artery stenosis, increased common carotid stiffness is associated with previous ischemic stroke and TIA. Measurement of carotid stiffness may improve selection of high-risk patients eligible for carotid endarterectomy and may guide new treatment strategies.