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
Andrew W. Asimos, MD, FACEP
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 W. Asimos, MD, FACEP
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
Andrew W. Asimos, MD, FACEP
Attending PhysicianAttending PhysicianEmergency MedicineEmergency Medicine
Carolinas Medical CenterCarolinas Medical CenterDepartment of Emergency MedicineDepartment of Emergency Medicine
Charlotte, NCCharlotte, NC
Andrew W. Asimos, MD, FACEP
Andrew W. Asimos, MD, FACEP
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
Andrew W. Asimos, MD, FACEP
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?
Andrew W. Asimos, MD, FACEP
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?
Andrew W. Asimos, MD, FACEP
Early Risk First Emphasized in 1973Early Risk First Emphasized in 1973
Andrew W. Asimos, MD, FACEP
Early Risk First Emphasized in 1973Early Risk First Emphasized in 1973
Andrew W. Asimos, MD, FACEP
27 Years Later27 Years Later
Andrew W. Asimos, MD, FACEP
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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
Andrew W. Asimos, MD, FACEP
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
Andrew W. Asimos, MD, FACEP
Independent Risk Factors for Independent Risk Factors for Stroke within 90 DaysStroke within 90 Days
Odds Ratio(95% CI)
P Value
Age > 60 y 1.8 (1.1-2.7) .01
Diabetes Mellitus 2.0 (1.4-2.9) <.001
> 10 min Duration 2.3 (1.3-4.2) .005
Weakness 1.9 (1.4-2.6) <.001
SpeechImpairment
1.5 (1.1-2.1) .01
Johnston SC et al. JAMA 2000;284:2901-2906.
Andrew W. Asimos, MD, FACEP
90-Day Stroke Risk by Number of 90-Day Stroke Risk by Number of Risk FactorsRisk Factors
# RiskFactors
Patients Stroke within90 days
0 22 (1) 0 (0)1 179 (10) 5 (3)2 509 (30) 35 (7)3 584 (34) 63 (11)4 337 (20) 51 (15)5 76 (4) 26 (34)
No. (%)
Johnston SC et al. JAMA 2000;284:2901-2906.
Andrew W. Asimos, MD, FACEP
Andrew W. Asimos, MD, FACEP
ABCD ScoreABCD Score
Risk Factor Score
Age ≥60 1
SBP >140 mm Hg and /or DBP ≥90 mm Hg at TIA presentation
1
Unilateral weakness 2
Speech disturbance without weakness 1
Symptom duration ≥60 minutes 2
Symptom duration 10-59 minutes 1
Symptom duration <10 minutes 0
Rothwell et al. Lancet 2005;366:29-36.
Andrew W. Asimos, MD, FACEP
7-Day Stroke Risk Stratified According to ABCD Score:7-Day Stroke Risk Stratified According to ABCD Score:OXVASC Validation CohortOXVASC Validation Cohort
Rothwell et al. Lancet 2005;366:29-36.
Andrew W. Asimos, MD, FACEP
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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%
Andrew W. Asimos, MD, FACEP
Ability of the ABCDAbility of the ABCD22 Score to Identify Low- Score to Identify Low-Risk TIA Cases in Community-Based ED’sRisk TIA Cases in Community-Based ED’s
• 4 community-based ED’s
• ED-based operational definition of TIA
• Dichotomized ABCD2 score at 4
• 358 cases
• Definition of a completed stroke unclear
Reeves MJ. International Stroke Conference, February, 21, 2008
Andrew W. Asimos, MD, FACEP
90-day events by ABCD90-day events by ABCD22 Score Score
Reeves MJ. International Stroke Conference, February, 21, 2008
Score N Stroke
Low Risk (ABCD2 ≤ 3) 95 (28%) 0 (0%)
Moderate Risk (ABCD2 4-5) 176 (52%) 6 (3.4%)
High Risk (ABCD2 ≥ 6) 67 (20%) 2 (3.0%)
Total 338 8 (2.4%)
Andrew W. Asimos, MD, FACEPReeves MJ. International Stroke Conference, February, 21, 2008
Andrew W. Asimos, MD, FACEP
North Carolina Collaborative North Carolina Collaborative TIA Risk Validation StudyTIA Risk Validation Study
Andrew W. Asimos, MD, FACEP
Andrew W. Asimos, MD, FACEP
Benign Recurrent TIAsBenign Recurrent TIAs
Johnston SC et al. Neurology 2003;60:280-285.
Andrew W. Asimos, MD, FACEP
MRI versus CTMRI versus CT
• DWI imaging on MRI can detect ischemic lesions within minutes of the event
Andrew W. Asimos, MD, FACEP
2006 NSA TIA Evaluation2006 NSA TIA EvaluationConsensus GuidelinesConsensus Guidelines
Andrew W. Asimos, MD, FACEP
2008 European TIA Evaluation2008 European TIA EvaluationConsensus GuidelinesConsensus Guidelines
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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.
Andrew W. Asimos, MD, FACEP
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)
Andrew W. Asimos, MD, FACEP
Stroke Risk After TIAStroke Risk After TIA
Giles MF et al. Lancet Neurology 2007;6:1063–1072.
Urgent Evaluation Associated with Lower Risk
Andrew W. Asimos, MD, FACEP
Questions?Questions?
[email protected]@carolinas.org
ferne_clindec_2008_tia_asimos_image_risk_extended_062508_final
