1. Symptomatic vs. Asymptomatic Carotid Endarterectomy
Morag Patterson
March 12th 2008

2. Content
Overview of evidence for carotid endarterectomy in symptomatic and asymptomatic patients
Compare clinically relevant data
Points to consider

3. Sources Cochrane review
Cina CS, Clase CM, Haynes RB. Carotid endarterectomy for symptomatic carotid stenosis. Cochrane Database of Systematic Reviews 1999, Issue 3. Art. No.: CD DOI: / CD

4. Sources Cochrane review
Chambers BR, Donnan GA. Carotid endarterectomy for asymptomatic carotid stenosis. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD DOI: / CD pub2.

5. Sources Draft version of SIGN guideline
Management of patients with stroke or TIA: assessment, investigation, immediate management and secondary prevention
Draft version of NICE guideline
Stroke: diagnosis and initial management of acute stroke and TIA

6. Modified Rankin Score 0 No symptoms at all
1 Significant disability despite symptoms; able to carry out all usual duties and activities
2 Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance
3 Moderate disability; requiring some help, but able to walk without assistance
4 Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance
5 Severe disability; bedridden, incontinent and requiring constant nursing care and attention
6 Dead

7. Symptomatic 3 trials included (~6000 patients)
European Carotid Surgery Trial
North American Symptomatic Carotid Endarterectomy Trial
Veterans Affairs Cooperative Studies Program

8. Symptomatic
Carotid stenosis and TIA/MS in the territory of that artery (6/12)
Best medical therapy vs BMT + surgery
Outcome of death or major disability from stroke (MRS ≥ 3)

9. Exclusion Criteria Patients at “highest risk”
ECST - equipoise, uncertainty principle
Severe co-morbidity
Tandem lesion (above C2)
Prior ipsilateral surgery

10. Results ECST NASCET RRR/I (95% CI) ARR/I (95% CI) NNT/H 82-99 70-99
(27-63)
ARR 6.7%
(3.2-10)
NNT 15
(10-31)
70-81
50-69
RRR 27%
(5-44)
ARR
4.7%
( ) 21
(11-125)
<70
<50
RRI
20%
0-44
ARI
2.2%
(0-4.4)
NNH 45
(22-inf)

11. Perioperative Outcomes
MI (1-2%)
Wound infection (3%)
Haematoma (5%)
Reversible nerve injury (5-7%)
RR disabling stroke or death 2.5 in first 30 days after randomisation

12. Asymptomatic 3 trials included (5223 patients)
Veterans Affairs Cooperative Study
Asymptomatic Carotid Atherosclerosis Study
Asymptomatic Carotid Surgery Trial

13. Asymptomatic Asymptomatic carotid stenosis
no history at all of cerebrovascular symptoms
remote (more than six months) ipsilateral carotid territory symptoms
prior symptoms in the vertebrobasilar circulation
prior carotid territory symptoms or a history of CEA on the contra-lateral side

14. Asymptomatic Best medical therapy vs. BMT + surgery Primary outcome
Perioperative stroke or death, or stroke of any territory or type during follow up

15. Asymptomatic
Perioperative stroke (of any territory or type) or death (from any cause), including the interval from randomisation to surgery and 30 days after surgery.
Perioperative stroke or death or ipsilateral carotid territory stroke of any pathological type during subsequent follow up.
Any stroke or death during the perioperative period and subsequent follow up.

16. Results Outcome RRR (CI) ARR
PSoD or ipsilateral carotid territory stroke of any type
29% (10-40) -
PSoD or stroke of any territory or type
31% (17-43) 1%
Any stroke or death
8% NS
PSoD = perioperative stroke or death

17. Conclusions Symptomatic Asymptomatic RRR of 48% ARR of 6.7%
(>70% stenosis)
RRR of 30%
ARR of 1%
(>60% stenosis)
Outcome measure in studies was death or major disability from stroke
Outcome measure in studies was perioperative stroke or death or any subsequent stroke

18. Conclusions Symptomatic Asymptomatic
Patients with >50% stenosis should be considered for surgery.
(50-69% male/within 2/52)
Studies underpowered to determine differences in degree of stenosis - data suggests less benefit with high grade stenosis
Increasing age and male sex confers increased ability to benefit (esp in lesser degree of stenosis)
RRR for men > for women (51%vs 4%)
RRR for younger age group > older (50% vs 9%)

19. Conclusions Symptomatic Asymptomatic
Surgically fit patients and surgeon with <6% peri-operative complication
Surgically fit patients and surgeon with <3% peri-operative complication
Contralateral occlusion confers higher operative risk but persistent benefit
Contralateral occlusion erases small benefit of CEA
Surgery ceases to be of value after 12 weeks (m) and 2 weeks (w) (>70%)
? ACST only 88% had CEA within 12/12

20. Points to Consider
BMT moved on since early 90s - erase benefit in 50-69% stenosis group?
Rothwell PM, Mehta Z, Howard SC, Gutnikov SA, Warlow CP. From subgroups to individuals: general principles and the example of carotid endartectomy. Lancet 2004; 365;
Peri-operative risk assessment