TIA risk stratification

1. TIA Risk Stratification
Dan Stevens
ED Registrar

2. The Charlie’s Way…..
• IV access, bloods
• ECG
• CT head
• Neurology Admit
• What do Neurology do?
– Diffusion weighted MRI
– Carotid angiography
– Carotid Doppler
– Modify treatable risk factors (HTN, cholesterol, Diet
advice, exercise, smoking cessation)

3. The UK Way

4. NICE Guidelines
• Start Aspirin 300mg (consider other modifiable
risk factors)
• Use a validated scoring system ABCD2
• 4 or more = admit
• 3 or less = home
– Specialist assessment within 1 week
– Diffusion weighted MRI within 1 week
– Carotid Doppler within 1 week
– Carotid endarterectomy within 2 weeks (if 70 – 99%
stenosis)

5. The ABCD2 Score
Predictor Points
Age > 60 1
Blood Pressure > 140/90 1
Clinical Features (max 2)
Unilateral weakness
Speech difficulty without weakness
2
1
Duration (max 2)
> 60 min
10 – 59 min
< 10 min
2
1
0
Diabetes 1
Maximum 7

6. How useful is it?
• Well used ?well validated
– Variable sensitivity
– Variable specifity
– Poor predictor of positive further diagnostic
testing

7. Why risk stratify in TIA?
• TIA carries a risk of stroke
– At 7 days 0.2 – 10%
– At 90 days 1.2 – 12%

8. What do we want?
An ED Risk stratification model that:
•Identifies those at high risk of imminent stroke
•Quickly Identifies the treatable factors that
puts them at risk
•Treat these risk factors in a timely manner

9. A New Approach

10. Monash Transient Ischemic Attack
Triggering Treatment Pathway (M3T)
• ED assessment
• Cresendo TIA or ongoing symptoms – admit
• TIA with resolved symptoms – ED Testing
– CT brain
– ECG
– Carotid USS
– Blood Tests
• Start Antiplatelet / anticoagulant (If AF), statin,
ACEi
• Discharge Home

11. M3T continued….
• ED physicians fax a referral to daily TIA clinic
• Stroke Reg and receptionist triage referrals on a daily basis
• Priority appointments for patients with ipsilateral internal
carotid stenosis > 50%
• Then CT or MRI angiography is arranged within 24 hours
• Immediate referral for surgical intervention if confirmed
stenosis > 70%
• Patients with AF also receive priority review to assess
anticoagulation
• Patients without AF or Carotid stenosis are allocated less
urgent appointments (4-6 weeks)
• Prior to this trial TIA patients were admitted to hospital

12. Results
• Primary outcome, stroke at 90 days
– 1.50% in M3T
– 4.67% in previous model
• ABCD2 score did not predict outcome in either
M3T trial or in previous model
• Significant cost reduction though reduction of
hospital admission

13. Summary
• Currently no perfect model for risk
assessment
• A well managed non-admission based TIA
model of care is likely to be safe
• This should be directed towards rapid
diagnosis of treatable pathology (AF, carotid
stenosis)
• This would likely reduce costs (as well as
reduce the patient risks of inpatient care)

14. Resources
• NICE Guideline - Stroke
https://www.nice.org.uk/guidance/cg68
• Emergency Medicine Practice 2013
http://www.ebmedicine.net/media_library/files
/0113%20TIA.pdf