Rothwell et al developed a risk model for patients with significant stenosis of the internal carotid artery. This can help identify those patients who may benefit from having surgical intervention vs medical management. The authors are from the Radcliffe Infirmary, Oxford, and Western General Hospital, Edinburgh. The study was done by the European Carotid Surgery Trialists' Collaborative Group.
Competing facts affecting decision making for a patient with carotid artery stenosis:
(1) risk of stroke in 3 years on medical management is 20%
(2) endarterectomy reduces risk of stroke by 50%
(3) endarterectomy can be associated with significant morbidity and mortality
Patient selection:
(1) carotid stenosis 70-99%
(2) symptomatic
Scores:
(1) risk score for medical management (risk of ipsilateral stroke in 5 years)
(2) risk score for surgery (risk of stroke or death within 30 days after surgery)
(3) predictive score (risk reduction with endarterectomy)
Parameters for medical risk:
(1) cerebral vs ocular events
(2) plaque surface irregularity
(3) any cerebrovascular events within the past 2 months
(4) carotid stenosis
|
Parameter |
Finding |
Points |
|
cerebral vs ocular events |
cerebral event |
1 |
|
|
ocular event |
0 |
|
plaque surface irregularity |
irregular |
1 |
|
|
smooth, regular |
0 |
|
any cerebrovascular events in past 2 months |
yes |
1 |
|
|
no |
0 |
|
carotid stenosis |
70 - 79% |
0 |
|
|
80-89% |
1 |
|
|
90-99% |
2 |
Parameters for surgical risk:
(1) gender
(2) peripheral vascular disease
(3) systolic blood pressure
|
Parameter |
Finding |
Points |
|
gender |
female |
1 |
|
|
male |
0 |
|
peripheral vascular disease |
present |
1 |
|
|
absent |
0 |
|
systolic blood pressure |
> 180 mm Hg |
1 |
|
|
<= 180 mm Hg |
0 |
risk score for medical management =
= SUM(points for all 4 risk factors)
risk score for surgical endarterectomy =
= SUM(points for all 3 parameters)
predictive score =
= (risk score for medical management) - (0.5 * (surgical risk score))
Interpretation:
• minimum risk scores: 0
• maximum medical risk score: 5
• maximum surgical risk score: 3
• minimum predictive score: -1.5
• maximum predictive score: 5
|
Medical Risk Score |
5 Year Actuarial Risk |
|
0 |
0 |
|
1 |
6% |
|
2 |
13.1% |
|
3 |
21% |
|
4 |
45.2% |
|
5 |
38.1% |
|
Surgical Risk Score |
30 Day Risk |
|
0 |
4.7% |
|
1 |
7.3% |
|
2 |
12.1% |
|
3 |
16.7% |
|
Predictive Score |
Endarterectomy |
|
<= 1 |
harmful |
|
1.5 - 3.5 |
no benefit |
|
4 - 5 |
beneficial |
Specialty: Neurology
ICD-10: ,
