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

Carotid Stenosis --- diagnosis. --- United States

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This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact

Stroke --- Elderly --- Carotid Stenosis --- Thrombectomy

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PURPOSE: To evaluate the evidence on screening and treating asymptomatic adults for carotid artery stenosis (CAS) for the U.S. Preventive Services Task Force (USPSTF). DATA SOURCES: PubMed/MEDLINE, the Cochrane Library, EMBASE, and trial registries through September 2013; reference lists of published literature; MEDLINE searches for trials were updated through March 2014. STUDY SELECTION: Two investigators independently selected studies reporting on asymptomatic adults with CAS, including randomized, controlled trials (RCTs) of screening for CAS; RCTs of carotid endarterectomy (CEA) or carotid angioplasty and stenting (CAAS) versus medical treatment; RCTs of medications versus placebo added to current standard medical therapy; multi-institution trials or cohort studies reporting harms; relevant systematic reviews; and studies that attempted to externally validate risk stratification tools. DATA EXTRACTION: One reviewer extracted data and a second checked accuracy. Two independent reviewers assigned quality ratings using predefined criteria. DATA SYNTHESIS: No RCTs compared screening with no screening, CAAS with medical treatment, or assessed intensification of medical therapy. Given the specificity of ultrasound (range 88% to 94% for CAS e50% to e70%), its use in low-prevalence populations would yield many false-positive results. Only one fair-quality study attempted external validation of a risk stratification tool to distinguish persons who are more likely to have CAS; the tool's discrimination was inadequate (c-statistic for e50% CAS, 0.60; 95% CI, 0.56 to 0.64). Our meta-analyses of RCTs comparing CEA with medical therapy found an absolute risk reduction of 5.5 percent (95% CI, 3.9 to 7.0) for any nonperioperative stroke over approximately 5 years. Meta-analyses for perioperative (30-day) stroke or death after CEA found rates of 2.4 percent (95% CI, 1.7 to 3.1) using all trials of CEA, regardless of the comparator; and 3.3 percent (95% CI, 2.7 to 3.9) using cohort studies (7 studies; n=17,474). Rates of perioperative stoke or death after CAAS were similar or slightly higher. Other important potential harms of CEA or CAAS include nonfatal perioperative myocardial infarction (approximately 0.8% rate after CEA), cranial nerve injury, pulmonary embolism, pneumonia, local hematoma requiring surgery, and psychological harms (e.g., anxiety or labeling). Externally validated, reliable risk stratification tools that can distinguish persons with asymptomatic CAS who have increased or decreased risk for ipsilateral stroke or harms after CEA or CAAS are not available. LIMITATIONS: Medical therapy in trials varied and often lacked treatments that are now standard. For this reason, and because advances in medical therapy have reduced the rate of stroke in persons with asymptomatic CAS in recent decades, the true reduction of stroke or composite reduction of cardiovascular events is unknown. Trials utilized highly selected surgeons. No trials focused on a population identified by screening in primary care. Harms may be underreported. CONCLUSION: Current evidence does not sufficiently establish incremental overall benefit of CEA, CAAS, or intensification of medical therapy beyond current standard medical therapy. Potential for overall benefit is limited by low prevalence in the general asymptomatic population and by harms from screening and treatment. Evidence is insufficient to allow reliable risk stratification.

Carotid Stenosis --- diagnosis. --- United States

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

Carotid Stenosis --- diagnosis. --- United States

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Stroke is a leading cause of death in the United States. Although the number of deaths from stroke has declined in recent years, it continues to be a major public health problem in the United States, with an estimated $34.3 billion in direct cost and indirect cost of stroke in the year 2008. Carotid artery stenosis represents an important risk factor for ischemic stroke, which accounts for nearly 90 percent of all strokes among U.S. men and women. Carotid artery stenosis is increasingly prevalent from the fifth decade of life onward. Patients with vascular disease and multiple risk factors (e.g., diabetes, hypertension, hyperlipidemia, and smoking) have a higher probability of having asymptomatic carotid stenosis. Since carotid artery atherosclerosis can largely proceed silently and unpredictably, the first manifestation can be a debilitating or fatal stroke. Asymptomatic carotid artery stenosis affects approximately 7 percent of women and over 12 percent of men, older than 70 years of age. Clinically important stenosis, at which the risk of stroke is increased, is defined as stenosis of over 50 or 60 percent. Natural history studies have reported that patients with asymptomatic carotid stenosis are at an increased risk of ipsilateral carotid territory ischemic stroke ranging from 5 to 17 percent. The goal of management of asymptomatic carotid stenosis is to decrease the risk of stroke and stroke-related deaths. However, screening asymptomatic patients for carotid stenosis is not part of common clinical practice as noted in a review by the U.S. Preventive Services Task Force from 1996, which concluded that evidence was insufficient to recommend either for or against screening. As the general U.S. population ages, and with the availability of noninvasive imaging studies, asymptomatic carotid artery stenosis may be more frequently detected in the course of patient management. Auscultation of the carotid arteries to listen for bruits is by convention an initial means of clinical assessment of high-risk patients, but the presence of bruits is not necessarily indicative of significant stenosis. Since carotid auscultation has limited sensitivity in detecting significant carotid stenosis, additional imaging modalities including digital subtraction angiography (DSA), Doppler ultrasound (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) are being increasingly utilized. The most commonly used measurement method of carotid stenosis used in clinical trials or most common angiographic method was introduced in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). In the NASCET method, the stenosis is measured as the ratio of the linear luminal diameter of the narrowest portion of the artery's diseased segment divided by the diameter of the healthy distal carotid artery (above the post-stenotic dilation). An alternative method was used in the European Carotid Surgery Trial (ECST), which utilized the estimated carotid bulb at the site of maximal stenosis as the denominator. The ECST method tends to yield higher degrees of stenosis, but measurements made by each method can be converted to those of the other using a simple arithmetic equation. According to the 2003 Society of Radiologists in Ultrasound consensus criteria, a carotid stenosis is not quantified as an exact percentage of luminal stenosis but can be classified by range of stenoses that represent clinically relevant categories (normal, < 50 percent, 50-69 percent, ≥ 70 percent but less than near occlusion, near occlusion, or total occlusion). Therapeutic options in asymptomatic carotid stenosis include medical therapy alone, carotid endarterectomy (CEA) and medical therapy, or carotid angioplasty and stenting (CAS) and medical therapy. However, the optimal therapeutic management strategy for patients with asymptomatic carotid stenosis is unclear. The Centers for Medicare and Medicaid Services (CMS) is interested in a systematic review of the literature on these three treatment strategies in patients with asymptomatic carotid stenosis. The Coverage and Analysis Group at the CMS requested the present report from the Technology Assessment Program (TAP) at the Agency for Healthcare Research and Quality (AHRQ). AHRQ assigned this report to the Tufts Evidence-based Practice Center (Tufts EPC) (Contract number, HSSA 290 2007 10055 I).

Carotid Stenosis --- Vascular Surgical Procedures --- Stents --- Stroke --- Treatment Outcome --- surgery. --- prevention & control.