Progression Rate and Ipsilateral Neurological Events in Asymptomatic Carotid Stenosis

Abstract

Background and Purpose— Progression of asymptomatic carotid stenoses with >50% luminal narrowing is associated with an increased risk of stroke. The significance of the progression rate in these patients is unknown. The main aim of this study was to evaluate the rate of change of carotid luminal narrowing over 1 year, as a risk factor for ipsilateral ischemic events, in patients with a >50% asymptomatic carotid stenosis. Secondary aims were to establish the incidence of changes in carotid luminal narrowing and establish additional risk factors for ipsilateral neurological events. Methods— A retrospective analysis was conducted of data derived from the deferred endarterectomy arm of the Asymptomatic Carotid Surgery Trial. Patients were followed up for ≥5 years with serial carotid duplex examinations. Data were derived from information obtained at randomization and annual follow-up visits with carotid duplex examination. Potential risk factors for ipsilateral neurological events were analyzed in Poisson regression models. Results— Data from 1469 patients were included. Two hundred forty-four had ipsilateral events; 240 had ipsilateral carotid surgery; 370 died from nonstroke causes; and 82 had an asymptomatic carotid occlusion. The annual incidence of progression in the cohort as a whole was 5.2%. Ipsilateral events occurred in 17% of patients. Diabetes and previous contralateral symptoms showed a significant independent association with ipsilateral neurological events. Ipsilateral events were associated with high rates of progression over 1 year but not with low progression rates or regression. Conclusions— Fast rates of progression of carotid luminal narrowing should be interpreted as a sign of significantly increased risk of future ipsilateral neurological events.

Optimal Medical Management Reduces Risk of Disease Progression and Ischemic Events in Asymptomatic Carotid Stenosis Patients: A Long-Term Follow-Up Study

“…Progression of severity of carotid stenosis (PSCS) has been shown to be a marker of future risk of IS/TIA in many (though not all) studies [17,18,19]. The effect of OMT and risk control on PSCS has also not been well studied.…”

Risk of Stroke and Cardiac Events in Medically Treated Asymptomatic Carotid Stenosis

“…13 Fourth, our study patients did not have follow-up vessel imaging to look for progression of the stenosis as the progression of the luminal narrowing and carotid occlusion in ACS has been shown in studies to be associated with increased risk of stroke. 14,15 In conclusion, although the risk of stroke in patients with ACS is low, acute coronary events and vascular deaths are higher. This highlights the importance of intensive risk factor modification to reduce adverse cardiovascular events in ACS rather than carotid revascularization.…”

Moving Beyond Luminal Stenosis: Imaging Strategies for Stroke Prevention in Asymptomatic Carotid Stenosis

“…Though various sonographically determined plaque features have been proposed to aid in the identification of high-risk plaque such as plaque ulceration [57] or stenosis progression [58], perhaps the most well-studied [59,60,61,62,63,64,65,66,67] risk marker for which there is level 2a evidence [68] is the presence of predominantly echolucent plaque. Histopathologic investigations [69,70] suggest that predominantly echolucent plaque may contain a relatively high proportion of lipid-rich necrotic core or intraplaque hemorrhage, which are the known constituents of more advanced, complicated atherosclerotic plaque [37,38].…”

“…One such approach is the evaluation of carotid artery stenosis progression with serial sonography. Though to our knowledge there is no systematic review or meta-analysis on this topic, there are several studies [58,87,88,89,90] suggesting that the progression of carotid stenosis detected by duplex sonography predicts adverse cardiovascular clinical events and ipsilateral stroke. The most recent of these studies by Hirt [58] analyzed about 1,500 carotid subjects from the Asymptomatic Carotid Stenosis Trial (ACST) and provides detailed stroke risk information based on stenosis progression over time in strictly defined NASCET stenosis subgroups (50-69%, 70-89%, 90-99%, and 100%).…”

“…Though to our knowledge there is no systematic review or meta-analysis on this topic, there are several studies [58,87,88,89,90] suggesting that the progression of carotid stenosis detected by duplex sonography predicts adverse cardiovascular clinical events and ipsilateral stroke. The most recent of these studies by Hirt [58] analyzed about 1,500 carotid subjects from the Asymptomatic Carotid Stenosis Trial (ACST) and provides detailed stroke risk information based on stenosis progression over time in strictly defined NASCET stenosis subgroups (50-69%, 70-89%, 90-99%, and 100%). Clearly, though evaluation of high-risk plaque composition is highly valuable as it provides stroke risk information at a single time point, future stroke risk prediction studies would be strengthened by combining plaque vulnerability assessment with stenosis progression data, as most asymptomatic carotid stenosis patients do undergo periodic surveillance imaging.…”