Andrew W. Asimos, MD, FACEP Transient Ischemic Attack Patient Update: The Optimal Management of Emergency Department Patients With Suspected Cerebral Ischemia

Andrew W. Asimos, MD, FACEP

Transient Ischemic Attack Transient Ischemic Attack Patient Update: Patient Update:

The Optimal Management of The Optimal Management of Emergency Department Patients Emergency Department Patients

With Suspected Cerebral IschemiaWith Suspected Cerebral Ischemia


Acute Neuroimaging and Risk Acute Neuroimaging and Risk Stratification for Suspected TIA Stratification for Suspected TIA

Patients in the Emergency Patients in the Emergency DepartmentDepartment


Andrew Asimos, MDAndrew Asimos, MDDirector of Emergency Stroke CareDirector of Emergency Stroke CareDepartment of Emergency MedicineDepartment of Emergency Medicine

Carolinas Medical Center, Charlotte, NCCarolinas Medical Center, Charlotte, NC

Adjunct Associate Professor, Department of Emergency MedicineAdjunct Associate Professor, Department of Emergency MedicineUniversity of North Carolina School of Medicine at Chapel HillUniversity of North Carolina School of Medicine at Chapel Hill


Attending PhysicianAttending PhysicianEmergency MedicineEmergency Medicine

Carolinas Medical CenterCarolinas Medical CenterDepartment of Emergency MedicineDepartment of Emergency Medicine

Charlotte, NCCharlotte, NC



CME Disclosure StatementCME Disclosure Statement

• Emergency Medicine Advisory Board– Boehringer Ingelheim Pharmaceuticals

• Research support from the Foundation for Education and Research in Neurologic Emergencies (FERNE) and Emergency Medicine Foundation (EMF)

• Research support from Boehringer Ingelheim Pharmaceuticals


Session ObjectivesSession Objectives• What is the short term ischemic stroke risk for ED

patients with suspected cerebral ischemia who are diagnosed with a TIA?

• What TIA features or syndromes impart greater stroke risk, and can these patients be identified clinically or with TIA risk stratification tools?

• What is the role of MRI in TIA patient risk stratification?

• Can and should ED TIA patients be safely dispositioned home with outpatient follow-up and still have an optimal outcome, given the short-term ischemic stroke risk?


TIA Conceptual ChangeTIA Conceptual Change

• TIA is a process, not an event• Can we reliably predict who is at risk of

suffering a completed stroke within the first hours, days, or weeks of a presumed TIA?

• Can we acutely intervene in the TIA process and prevent a completed stroke from occurring?


Early Risk First Emphasized in 1973Early Risk First Emphasized in 1973


Early Risk First Emphasized in 1973Early Risk First Emphasized in 1973


27 Years Later27 Years Later



90-Day Prognosis after ED Diagnosis of TIA90-Day Prognosis after ED Diagnosis of TIA

• 10.5% will suffer a stroke– 21% will be fatal– 64% will be disabling– Half of these will occur within 1 - 2 days of ED

visit• 2.6% will die• 2.6% will suffer adverse cardiovascular

events• 12.7% will have additional TIAs

Johnston SC et al. JAMA 2000;284:2901-2906.


Stroke Risk after TIAStroke Risk after TIA

Giles MF et al. Lancet Neurology 2007;6:1063–1072.

18 independent cohorts

10,126 patients

Pooled stroke risk3.1% (95%CI 2.0-4.1) at 2 days5.2% (95% CI 3.9-6.5) at 7 days


Which TIA Patients are at Highest Risk?Which TIA Patients are at Highest Risk?

• A risk stratification score could help allocate expensive evaluation and treatment to the highest risk patients

• High risk patients might benefit more from hospital admission– If expedited ED evaluation not an option

• Outpatient evaluation for low risk patients



ABCDABCD22 Score Score

Variable Score

Age ≥ 60 years 1

First BP ≥ 140/90 mmHg 1

Clinical: Unilateral Weakness 2

Speech Impairment without weakness 1

Duration: 10-59 mins 1

≥ 60 mins 2

Diabetes Mellitus 1

Johnston SC et al. Lancet 2007;369:283-92.


ABCDABCD22 Score and Score andShort-term Stroke RiskShort-term Stroke Risk

Johnston SC et al. Lancet 2007;369:283-92.

StrokeRisk (%)

ABCD2 score

2-Day RiskLow Risk: Score 0-3 → 1%Moderate Risk: Score 4-5→ 4%High Risk: Score 6-7 → 8%


North Carolina Collaborative North Carolina Collaborative TIA Risk Validation StudyTIA Risk Validation Study



Benign Recurrent TIAsBenign Recurrent TIAs

Johnston SC et al. Neurology 2003;60:280-285.


MRI versus CTMRI versus CT

• DWI imaging on MRI can detect ischemic lesions within minutes of the event


2006 NSA TIA Evaluation2006 NSA TIA EvaluationConsensus GuidelinesConsensus Guidelines


2008 European TIA Evaluation2008 European TIA EvaluationConsensus GuidelinesConsensus Guidelines


Frequency of Positive Diffusion MRI:Frequency of Positive Diffusion MRI:5 Reported Series of TIAs5 Reported Series of TIAs

Ovbiagele B et al. Stroke 2003;34(4):919-24.


Do hyperacute DWI abnormalities in TIA patients Do hyperacute DWI abnormalities in TIA patients signify irreversible ischemic infarction?signify irreversible ischemic infarction?

• 21 consecutive TIA patients with DWI with 6 hours– Half DWI positive

• Follow-up MRI at 2-9 days– All initially positive DWI patients with

abnormalities on T2/FLAIR images

Inatomi Y et al. Cerebrovasc Dis 2005;19:362-368.


DWI Negative TIA Patients at Risk DWI Negative TIA Patients at Risk of Recurrent Transient Events of Recurrent Transient Events

• 85 TIA patients with DWI MRI within 24 hours

• DWI negative patients– 4.6 times (27% versus 6%) more likely to

have subsequent TIA (i.e. not a stroke)

– 4.3 times (2% versus 9%) less likely to have a stroke within one year

Boulanger J et al. Stroke 2007;38:2367-69.


MRI as a Tool for Risk StratifcationMRI as a Tool for Risk Stratifcation

• 90-day new stroke rate– 4.3% No DWI lesion– 11% DWI lesion and no vessel occlusion– 33% DWI lesion and vessel occlusion

• 60% of DWI+ patients “high-risk” compared with 9% of DWI- patients– OR 15.8 (95% CI 3.7-67.5)

Coutts SB et al. Ann Neurol 2005;57:848-854.

Cucchiara BL et al. Stroke 2006;37:1710-1714.


Association Between Positive DWI Imaging Association Between Positive DWI Imaging and Clinical Predictors of Early Strokeand Clinical Predictors of Early Stroke

Redgrave J et al. Stroke 2007;38:1482-1488.

Variable # studies OR (95% CI)

Duration ≥ 60 mins 13 1.5 (1.16-1.96)

Dysphasia 9 2.3 (1.57-3.22)

Dysarthria 8 1.7 (1.11-2.68)

Motor Weakness 9 2.2 (1.56-3.10)

Atrial Fibrillation 9 2.8 (1.78-4.25)

Ipsilateral ≥ 50 carotid stenosis

10 1.9 (1.34-2.76)


Stroke Risk After TIAStroke Risk After TIA

Giles MF et al. Lancet Neurology 2007;6:1063–1072.

Urgent Evaluation Associated with Lower Risk


Questions?Questions?

[email protected]@carolinas.org

ferne_clindec_2008_tia_asimos_image_risk_brief_062508_final

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Andrew W. Asimos, MD, FACEP Transient Ischemic Attack Patient Update: The Optimal Management of Emergency Department Patients With Suspected Cerebral Ischemia