Table 1. Evidence Table for Randomized, Controlled Trials for Effectiveness of Surgery versus Medical Management for Asymptomatic Carotid Artery Stenosisa

Study, Year (Reference)Sample Characteristics Mean Follow-up 30-Day Perioperative Complication Rate 5-Year Outcomesb Quality Rating
VACS, 199331 n=444
MM group: 233
CEA group: 211

Mean age: 65 y
Men: 100%
White: 86% to 88%

 48 mo Stroke or death: 4.7%
MI: 1.9%		 5-year incidence of any stroke and perioperative death:
MM group: 44.2%
CEA group: 41.2%
RR, 0.92 (95% CI, 0.69–1.22)		 Fair
ACAS, 199532 n=1659
MM group: 834
CEA group: 825

Mean age: 67 y
Men: 66%
White: 94% to 95%

 2.7 y Stroke or death: 2.7%
MI: NR

By sex:
Women: 3.6%
Men: 1.7% 		Rate of perioperative stroke or death and subsequent ipsilateral stroke:
MM group: 11%
CEA group: 5.1%
RRR, 53% (CI, 22% to 72%)
ARR, 5.9%

By sex:
Women: RRR, 17% (CI, .96% to 65%)
Men: RRR, 66% (CI, 36% to 82%)

By age:
<68 y: RRR, 0.60 (CI, 0.11 to 0.82)
>68 y: RRR, 0.43 (CI,.0.07 to 0.70)

 Good
ACST, 200433 n=3120
MM group: 1560
CEA group: 1560

Mean age: 68 y
Men: 66%
White:NR

 3.4 y Stroke or death: 2.8%
MI: 0.6%

By sex:
Women: 3.1%
Men: 2.2%

By age:
<65 y: 2.4%
65–74 y: 2.3%
>75 y: 3.3%

 5-year incidence of any stroke and perioperative death:
MM group: 11.8% (SE .1.00%)
CEA group: 6.4% (SE .0.70%)
ARR, 5.4% (CI, 2.96% to 7.75%)

5-year incidence of nonperioperative stroke:
By sex:
Women: ARR, 4.1% (CI, 0.74% to 7.41%)
Men: ARR, 8.2% (CI, 5.64% to 10.78%)

By age:
<65 y: ARR, 7.8% (CI, 4.28% to 11.31%)
65–74 y: ARR, 7.5% (CI, 4.67% to 10.30%)
>75 y: ARR, 3.3%

 Good

a. For further details on these studies, go to Appendix Table 3. ACAS = Asymptomatic Carotid Atherosclerosis Study; ACST = Asymptomatic Carotid Surgery Trial; ARR = absolute risk reduction; CEA = carotid endarterectomy; MI = myocardial infarction; MM = medical management; NR = not reported; RR = relative risk; RRR = relative risk reduction; VACS = Veterans Affairs Cooperative Study.
b. Standard errors and 95% CIs are listed if they were reported in the studies.

Return to Document