Risk Score of Tu et al for Stroke and Death Within 30 Days After a Carotid Endarterectomy

 

Parameters:

(1) history of stroke or transient ischemic attack (TIA) in the 6 months prior to surgery

(2) occlusion of the contralateral carotid artery (100% block on angiography)

(3) history of atrial fibrillation

(4) history of congestive heart failure (CHF)

(5) history of diabetes mellitus

 

Parameter	Finding	Points
history of stroke or TIA	absent	0
	present	1
occlusion of contralateral carotid artery	absent	0
	present	1
history of atrial fibrillation	absent	0
	present	1
history of congestive heart failure	absent	0
	present	1
history of diabetes mellitus	absent	0
	present	1

 

total risk score =

= SUM(points for all 5 parameters)

 

Interpretation:

• minimum score: 0

• maximum score: 5

• The higher the score the more likely stroke or death within 30 days after surgery.

Points	Probability of Stroke or Death Within 30 Days
0	3%
1	6%
2	10%
3	10%
4	16%
5	not given

from Table 4, page 2571

 

The authors developed prognostic models for predicting death, nonfatal stroke, or a combination of both (see Table 2, page 2571).

 

value of X for death or stroke =

= (0.5590 * (points for TIA or stroke)) + (0.06350 * (points for atrial fibrillation)) + (0.5440 * (points for contralateral carotid occlusion)) + (0.5865 * (points for CHF)) + (0.2470 * (points for diabetes)) - 3.2831

 

probability of death or stroke =

= 1 / (1+ EXP((-1) * X))

 

value of Y for death =

= (0.5477 * (1 if COPD present, 0 if absent)) +(0.5321 * (1 if peripheral vascular disease present, 0 if absent)) + (0.3726 * (1 if age 65-75 years, 0 if not)) + (0.8255 * (1 if age >=75 years, 0 if not)) + (0.8889 * (points for contralateral carotid occlusion)) + (0.6906 * (points for CHF)) + (0.7570 * (points for diabetes)) - 5.2209

 

probability of death =

= 1 / (1+ EXP((-1) * Y))