TIA Risk Stratification

Dan StevensED Registrar

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)

The UK Way

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)

The ABCD2 ScorePredictor Points

Age > 60 1

Blood Pressure > 140/90 1

Clinical Features (max 2) Unilateral weakness Speech difficulty without weakness

21

Duration (max 2) > 60 min 10 – 59 min < 10 min

210

Diabetes 1

Maximum 7

How useful is it?

• Well used ?well validated– Variable sensitivity– Variable specifity– Poor predictor of positive further diagnostic

testing

Why risk stratify in TIA?

• TIA carries a risk of stroke– At 7 days 0.2 – 10%– At 90 days 1.2 – 12%

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

A New Approach

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

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

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

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)

Resources

• NICE Guideline - Strokehttps://www.nice.org.uk/guidance/cg68• Emergency Medicine Practice 2013http://www.ebmedicine.net/media_library/

files/0113%20TIA.pdf