Screening for carotid artery stenosis: An update of the evidence for the U.S. Preventive Services Task Force

University of North Carolina at Chapel Hill, North Carolina, United States
Annals of internal medicine (Impact Factor: 17.81). 01/2008; 147(12):860-70.
Source: PubMed


Cerebrovascular disease is the third leading cause of death in the United States. The proportion of all strokes attributable to previously asymptomatic carotid artery stenosis (CAS) is low. In 1996, the U.S. Preventive Services Task Force concluded that evidence was insufficient to recommend for or against screening of asymptomatic persons for CAS by using physical examination or carotid ultrasonography.
To examine the evidence of benefits and harms of screening asymptomatic patients with duplex ultrasonography and treatment with carotid endarterectomy for CAS.
MEDLINE and Cochrane Library (search dates January 1994 to April 2007), recent systematic reviews, reference lists of retrieved articles, and suggestions from experts.
English-language randomized, controlled trials (RCTs) of screening for CAS; RCTs of carotid endarterectomy versus medical treatment; systematic reviews of screening tests; and observational studies of harms from carotid endarterectomy were selected to answer the following questions: Is there direct evidence that screening with ultrasonography for asymptomatic CAS reduces strokes? What is the accuracy of ultrasonography to detect CAS? Does intervention with carotid endarterectomy reduce morbidity or mortality? Does screening or carotid endarterectomy result in harm?
All studies were reviewed, abstracted, and rated for quality by using predefined Task Force criteria.
No RCTs of screening for CAS have been done. According to systematic reviews, the sensitivity of ultrasonography is approximately 94% and the specificity is approximately 92%. Treatment of CAS in selected patients by selected surgeons could lead to an approximately 5-percentage point absolute reduction in strokes over 5 years. Thirty-day stroke and death rates from carotid endarterectomy vary from 2.7% to 4.7% in RCTs; higher rates have been reported in observational studies (up to 6.7%).
Evidence is inadequate to stratify people into categories of risk for clinically important CAS. The RCTs of carotid endarterectomy versus medical treatment were conducted in selected populations with selected surgeons.
The actual stroke reduction from screening asymptomatic patients and treatment with carotid endarterectomy is unknown; the benefit is limited by a low overall prevalence of treatable disease in the general asymptomatic population and harms from treatment.

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    • "CIMT is a useful marker for investigating the degree of early atherosclerosis. Several clinical studies have demonstrated that an increase in ultrasonographically measured CIMT is associated with elevated risks of cardiovascular diseases and stroke [11]. CIMT, as evaluated by ultrasound, correlates well with anatomic measurements and is recognized as a marker of preclinic atheroma. "
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    ABSTRACT: Background In patients with Obstructive sleep apnea (OSA), the risks of fatal and non-fatal cardiovascular diseases and coronary artery disease are increased and measuring carotid intima-media thickness (CIMT) can assess these complications. Aim Studying the effect of OSA syndrome in the carotid artery wall thickness as an indicator to cardiovascular complications, and the effect of CPAP on these changes. Subjects and methods Polysomnography (PSG) was done for 45 patients; 29 patients of them proved to have OSA, and 10 obese subjects with normal PSG were included as a control group. All of them had ultrasonographic assessment of CIMT. 17 patients with OSA used CPAP overnight for 6 months and the CIMT was remeasured. Results 29 were diagnosed with OSA (12 severe, 9 moderate and 8 mild OSA). There was a highly significant difference (p < 0.01) in CIMT between patient and control groups, and also between severe and mild OSA patients with non-significant difference (p > 0.05) between severe and moderate OSA. Regarding the different risk factors predispose to atherosclerosis, only factors related to OSA syndrome were correlated with CIMT. There was a highly significant reduction (p < 0.01) in CIMT after six months of CPAP usage. Conclusions CIMT as a marker of atherosclerosis is significantly increased in patients with OSA and the use of CPAP in those patients is very important not only for improving sleep efficiency but also for reducing cardiovascular complications associated with OSAS.
    Full-text · Article · Jan 2013
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    • "However, due to low absolute risk reduction of 1.2% the efficacy of surgical intervention has been questioned by means of calculations leading to a disclosure of costs of up to 580.000 AUS$ for one stroke prevented with prophylactic TEA in case of asymptomatic stenosis [3]. Costs may be even higher, taking into account, that the periprocedural complication rate of less than 3% in the multicenters trials was not confirmed in postapproval registries [4] [5]. A recent meta analysis went even further and calculated the difference in estimated fatal and disabling stroke-free survival in case of endarterectomy in patients with asymptomatic severe carotid stenosis as less than 4 days over the course of 5 years [6]. "
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    ABSTRACT: Operative treatment of asymptomatic carotid stenosis is well established since results of Asymptomatic Carotid Atherosclerosis Study (ACAS) trial and Asymptomatic Carotid Surgery Trial (ACST) were published. However, advances in medical treatment and recent trials that revealed success of “best medical treatment” over interventional treatment for stenosis of brain supplying arteries have raised the question, if “best medical treatment” should be considered as first option in case of asymptomatic carotid stenosis.
    Full-text · Article · Sep 2012 · Perspectives in Medicine
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    • "Carotid duplex ultrasonography (CDUS) is an accuracy-proven non-invasive diagnostic examination to detect asymptomatic carotid artery stenosis (ACAS). However, for the general population, CDUS has a limited role in screening of carotid disease because of a low overall prevalence of clinically relevant disease (9). Because coronary artery disease (CAD), cerebrovascular disease (CVD) and peripheral arterial disease (PAD) originate from atherosclerosis, these three diseases occasionally exist together (10). "
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    ABSTRACT: This study aimed to investigate prevalence of asymptomatic carotid artery stenosis (ACAS) in Korean patients with peripheral arterial disease (PAD) and identify predictive factors of ACAS in patients with PAD. Between 1994 and 2008, 546 patients who underwent bypass surgery due to PAD were identified in a single tertiary teaching hospital. Of those, 409 patients underwent preoperative screening carotid duplex ultrasonography (CDUS). Patients who had an episode of cerebrovascular event or previous carotid artery intervention were excluded and then a retrospective analysis was made of 340 patients. The degree of internal carotid artery (ICA) stenosis was determined by the criteria of Society of Radiologists in Ultrasound Consensus Conference. To determine the risk factors of ACAS, demographic, coexisting medical condition and lesion characteristics were tested with binary logistic regression model. The prevalence of > or = 70% ICA stenosis was 14%. ICA occlusion was detected in 7.1%. Multivariate analysis revealed age > 65 yr (OR: 2.610, 95% CI: 1.197-5.691) and coronary artery disease (CAD, OR: 2.333, 95% CI: 1.169-4.657) are predictive factors of > or = 70% stenosis. A PAD patient who needs revascularization, particularly, > 65 yr or has a concomitant CAD, can be a good candidate of screening CDUS.
    Full-text · Article · Aug 2010 · Journal of Korean medical science
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