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Meta-Analysis
. 2005 Oct 19;2005(4):CD001923.
doi: 10.1002/14651858.CD001923.pub2.

Carotid endarterectomy for asymptomatic carotid stenosis

B R Chambers  1 , G A Donnan
Affiliations
Meta-Analysis

Carotid endarterectomy for asymptomatic carotid stenosis

B R Chambers et al. Cochrane Database Syst Rev. .

Abstract

Background: Carotid endarterectomy (CEA) is of proven benefit in recently-symptomatic patients with severe carotid stenosis. Its role in asymptomatic stenosis is still debated. The Asymptomatic Carotid Surgery Trial (ACST) more than doubled the number of patients randomised to CEA trials. This revised review incorporates the recently published ACST results.

Objectives: Our objective was to determine the effects of CEA for patients with asymptomatic carotid stenosis.

Search strategy: We searched the Cochrane Stroke Group Trials Register (searched May 2004), MEDLINE (1966 to May 2004), EMBASE (1980 to June 2004), Current Contents (1995 to January 1997), and reference lists of relevant articles. We contacted researchers in the field to identify additional published and unpublished studies.

Selection criteria: All completed randomised trials comparing CEA to medical treatment in patients with asymptomatic carotid stenosis.

Data collection and analysis: Two reviewers extracted data and assessed trial quality. Attempts were made to contact investigators to obtain missing information.

Main results: Three trials with a total of 5223 patients were included. In these trials, the overall net excess of operation-related perioperative stroke or death was 2.9%. For the primary outcome of perioperative stroke or death or any subsequent stroke, patients undergoing CEA fared better than those treated medically (relative risk (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83). Similarly, for the outcome of perioperative stroke or death or subsequent ipsilateral stroke, there was benefit for the surgical group (RR 0.71, 95% CI 0.55 to 0.90). For the outcome of any stroke or death, there was a non-significant trend towards fewer events in the surgical group (RR 0.92, 95% CI 0.83 to 1.02). Subgroup analyses were performed for the outcome of perioperative stroke or death or subsequent carotid stroke. CEA appeared more beneficial in men than in women and more beneficial in younger patients than in older patients although the data for age effect were inconclusive. There was no statistically significant difference between the treatment effect estimates in patients with different grades of stenosis but the data were insufficient.

Authors' conclusions: Despite about a 3% perioperative stroke or death rate, CEA for asymptomatic carotid stenosis reduces the risk of ipsilateral stroke, and any stroke, by approximately 30% over three years. However, the absolute risk reduction is small (approximately 1% per annum over the first few years of follow up in the two largest and most recent trials) but it could be higher with longer follow up.

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Conflict of interest statement

None known

Figures

1.1
1.1. Analysis
Comparison 1 Carotid endarterectomy versus medical treatment, Outcome 1 Perioperative stroke or death.
1.2
1.2. Analysis
Comparison 1 Carotid endarterectomy versus medical treatment, Outcome 2 Perioperative stroke or death or subsequent ipsilateral stroke.
1.3
1.3. Analysis
Comparison 1 Carotid endarterectomy versus medical treatment, Outcome 3 Perioperative stroke or death or any subsequent stroke.
1.4
1.4. Analysis
Comparison 1 Carotid endarterectomy versus medical treatment, Outcome 4 Any stroke or death.
2.1
2.1. Analysis
Comparison 2 Subgroup analysis, Outcome 1 Gender.
2.2
2.2. Analysis
Comparison 2 Subgroup analysis, Outcome 2 Age.
2.3
2.3. Analysis
Comparison 2 Subgroup analysis, Outcome 3 Stenosis.
See this image and copyright information in PMC

Update of

References

References to studies included in this review

ACAS {published data only}
    1. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA 1995;273:1421‐8. - PubMed
    1. The Asymptomatic Carotid Atherosclerosis Study Group. Study design for randomized prospective trial of carotid endarterectomy for asymptomatic atherosclerosis. Stroke 1989;20:844‐9. - PubMed
ACST {published data only}
    1. Perioperative stroke or death in various subcategories. http://image.thelancet.com/extras/04art3083webtable.pdf.
    1. Halliday AW for the Steering Committee and for the Collaborators. The Asymptomatic Carotid Surgery Trial (ACST) rationale and design. European Journal of Vascular Surgery 1994;8:703‐10. - PubMed
    1. MRC Asymptomatic Carotid Surgery Trial (ACST) Collaborative Group. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: randomised controlled trial. Lancet 2004;363(9420):1491‐502. - PubMed
VA {published data only}
    1. Hobson RW. Role of carotid endarterectomy in asymptomatic carotid stenosis: a Veterans Administration Cooperative Study. Stroke 1986;17:534‐9. - PubMed
    1. Hobson RW, Weiss DG, Fields WS, Goldstone J, Moore WS, Towne JB, et al. Efficacy of carotid endarterectomy for asymptomatic carotid stenosis. New England Journal of Medicine 1993;328:221‐7. - PubMed

References to studies excluded from this review

AURC {published data only}
    1. Lagneau P. Asymptomatic carotid stenosis: analysis of randomised studies [Sténoses carotidiennes asymptomatiques: analyse des études randomisées]. Journal des Maladies Vasculaires 1993;18:209‐12. - PubMed
CASANOVA {published data only}
    1. The CASANOVA Study Group. Carotid surgery versus medical therapy in asymptomatic carotid stenosis. Stroke 1991;22:1229‐35. - PubMed
MACE {published data only}
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Additional references

Abbott 2005
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ECST
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MeSH terms