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With intensive medical therapy, the risk of stroke or death in patients with asymptomatic carotid stenosis (ACS) is now below the risk of carotid endarterectomy or stenting.
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Most ACS patients (∼90%) would be better off with medical therapy than with either intervention.
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The few patients who could benefit from intervention can be identified by transcranial Doppler embolus detection, reduced cerebral blood flow reserve, carotid ulceration on 3-dimensional ultrasound, intraplaque hemorrhage on MRI,
Management of Asymptomatic Carotid Stenosis
Section snippets
Key points
Disease Description
Asymptomatic carotid stenosis (ACS) refers to narrowing of the carotid artery caused by atherosclerosis in patients who have not experienced a stroke or transient ischemic attack in the territory of that artery. Patients with vague symptoms such as lightheadedness, or symptoms in the vertebrobasilar territory should not be regarded as symptomatic, for the purpose of managing their carotid stenosis.
The term is sometimes applied to patients who may have experienced a transient ischemic attack
Cardiovascular risk of patients with asymptomatic carotid stenosis
Patients with ACS are at a high risk of myocardial infarction, so they warrant intensive medical therapy. Indeed, in the Veterans Affairs study in 1994,8 the risk of myocardial infarction among patients with ACS was 33% over 4 years, similar to the risk of patients with known coronary disease. Among patients with ACS and no known coronary disease, their first event was myocardial infarction in 56% of cases. It is therefore axiomatic that all patients with asymptomatic stenosis should receive
Management of patients with asymptomatic carotid stenosis
As described by Spence and Hackam in 2010,15 and illustrated in the Stenting Versus Aggressive Medical Therapy for Intracranial Arterial Stenosis (SAMPRISS) trial,16 in which the risk of stroke was higher with stenting of intracranial arteries than with intensive medical therapy, there is much more to intensive medical therapy than aspirin and a small dose of statin drugs. Comprehensive management of ACS should include lifestyle modification, effective blood pressure control, antiplatelet
Metabolic vitamin B12 deficiency
Metabolic B12 deficiency is common (30% of patients over age 71 attending a stroke prevention clinic)43 and frequently missed, because serum B12 measures total B12, not active B12. To ascertain adequacy of functional B12, it is necessary to measure holotranscobalamin, or to assess the function of B12 by measuring methylmalonic acid, or in folate-replete patients, total homocysteine (tHcy). High levels of tHcy increase the risk fourfold among patients with atrial fibrillation,44 and are
Current Guidelines
A PubMed search on the terms “asymptomatic carotid stenosis” and “guideline” (publication type) or “consensus development conference” (publication type) yielded 4 references.48, 49, 50, 51 Of these, one was a paper about research priorities of the Society for Vascular Surgery, with no guideline provided51; two were Italian national guidelines from 200648 and 2009,49 and one was an Australasian guideline from 2010.50 In addition, there is a guideline from the American Academy of Neurology,52 a
Summary
Patients with ACS are at high risk of myocardial infarction and require intensive medical therapy; such therapy has reduced the risk of stroke to well below the risk of carotid endarterectomy or stenting. Most patients with ACS should be treated only with intensive medical therapy including lifestyle change. The few patients who could benefit from revascularization can be identified by procedures such as microembolus detection on TCD, and most of these should be offered endarterectomy in
Disclosures
Dr J.D. Spence has received grants from the Canadian Institutes for Heath Research, Heart & Stroke Foundation of Canada (HSF), and the National Institute of Health/National Institute of Neurologic Disorders and Stroke. Lecture honoraria/travel support/consulting fees were provided by Sanofi-Synthelabo, Bayer, Merck and Boehringer Ingelheim. Research support for investigator-initiated projects was provided by Pfizer (substantial donation in kind of study medication to support HSF grant for
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Cited by (24)
Symptom Status of Patients Undergoing Carotid Endarterectomy in Canada and United States
2022, Annals of Vascular SurgeryCitation Excerpt :Since then, there have been significant advances in the medical management of cardiovascular diseases, particularly with widespread use of antiplatelets and statins.23,24 This has significantly reduced stroke/death rates in patients with asymptomatic carotid stenosis, thereby decreasing the already marginal benefit from revascularization.25–29 Further guidance around the selection of patients with asymptomatic disease for intervention may better standardize care.
Initial Results of Selected Use of Covered Stents in Transcarotid Artery Revascularization
2020, Annals of Vascular SurgeryCitation Excerpt :Carotid stenosis is a common disease that carries significant risk of ischemic stroke.3–5
Carotid, Vertebral, and Brachiocephalic Interventions
2020, Interventional Cardiology ClinicsCitation Excerpt :According to a recent report, both CAS and CEA are performed predominantly for patients with asymptomatic carotid stenosis.27 Annual rates of ipsilateral ischemic strokes have fallen significantly with medical therapy alone secondary to the increasing use of efficient medical therapy, including aspirin, statin, antiplatelets, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, along with lifestyle modifications.28,29 Effective usage of medical therapy could be seen from the increasing trend of medication usage in the Asymptomatic Carotid Surgery Trial (ACST) in which use of lipid-lowering therapy increased from 17% around 1996 to almost 58% around 2003.
Review of serum biomarkers in carotid atherosclerosis
2020, Journal of Vascular SurgeryQuality improvement guidelines for adult diagnostic cervicocerebral angiography: Update cooperative study between the Society of Interventional Radiology (SIR), American Society of Neuroradiology (ASNR), and Society of NeuroInterventional Surgery (SNIS)
2015, Journal of Vascular and Interventional RadiologyCitation Excerpt :Also, it should be noted that the utility of CCA may vary based on locally available tools, technique, and expertise in each institution. Indications for CCA may include the following (1,4,6–8,28,41,64–160): Evaluate cervicocerebral circulation when CT angiography or MR angiography is inconclusive or rendered nondiagnostic as a result of patient-related factors such as significant metal artifact or poor cardiac output.
Disclosure: See last page of article.