CAROTID STENOSIS (SYMPTOMATIC, HIGH GRADE) BENEFITS FROM ENDARTERECTOMY (NASCET).
Clinical Bottom Line:
In pts with recent hemispheric or retinal TIAs or nondisabling strokes, who have 70-99% stenosis of ipsilateral ICA, carotid endarterectomy decreases the risk of all stroke (NNT=7), major or fatal stroke (NNT=11), and major stroke or death (NNT=10) at 2 yrs. |
Appraised by: Sharon Straus & Dave Sackett; Sept 26, 1996
The Patient:
72 yr old man with left sided weakness, past medical history unremarkable.
Three-part Question:
In patients with a recent cerebrovascular event, does carotid endarterectomy reduce the risk of subsequent major stroke and death?
Search Terms:
carotid endarterectomy in Best Evidence
The Study:
- Pts <80 yrs old, hemispheric TIA or monocular blindness <24 hrs or nondisabling stroke within previous 120 days in association with stenosis of 30-99% in ipsilateral ICA who were stratified into 2 strata 30-69% and 70-99% stenosis.
- Control group: (N=331) Medical care consisted of ASA (1300 mgs unless side effects), treatment of hypertension, hyperlipidemia or diabetes if appropriate. Follow up at 1,3,6,9,12 months and then q 4 months thereafter.
- Experimental group: (N=328) Medical care and carotid endarterectomy. Follow up as with control group.
The Evidence:
| Outcome | Time to Outcome | RRR | ARR | NNT |
| any stroke | 2 yrs | 54% | 0.150 | 7 | |
|---|
| 95% CI: | 33% to 76% | 0.090 to 0.210 | 5 to 11 |
| major or fatal stroke | 2 yrs | 72% | 0.094 | 11 |
|---|
| 95% CI: | 40% to 100% | 0.052 to 0.136 | 7 to 19 |
| any major stroke or death | 2 yrs | 56% | 0.101 | 10 |
|---|
| 95% CI: | 28% to 84% | 0.050 to 0.152 | 7 to 20 |
Comments:
- trial stopped early in pts with high grade stenosis because of evidence of efficacy of surgery
- no patient lost to follow up and no pt withdrawn
- extrapolation to your hospital - if your hospital's perioperative risk of major stroke and death exceeds 2.1%, benefit of surgery starts to fall and if the rate of major complications approaches 10% the benefit vanishes entirely.
Expiry date: Sept 26, 1997
References:
- NASCET Collaborators: Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med 1991;325:445-53
