Transcript Transient Ischemic Attack (TIA): The Calm Before the Storm Raymond Reichwein, M.D. Associate Professor of Neurology Penn State University College of Medicine Milton S.

Transient Ischemic Attack (TIA):
The Calm Before the Storm
Raymond Reichwein, M.D.
Associate Professor of Neurology
Penn State University College of Medicine
Milton S. Hershey Medical Center
January 8, 2009
Disclosures
• Boehringer Ingelheim
• Genentech
• AGA Medical Corp
OBJECTIVES
• Discuss the importance of TIA and future
stroke risk.
• Discuss optimal TIA evaluation and
management.
• Briefly discuss future stroke prevention,
from both an antiplatelet/anticoagulant
therapy and risk factor management
standpoint.
Stroke in the US
• 730,000 new or recurrent strokes each year1
• 167,366 deaths in 1999 (1 of every 14.3 deaths)2
• 4,600,000 stroke survivors alive today2
• Origin of strokes3
– 80% ischemic
– 20% hemorrhagic
1. Broderick J et al. Stroke. 1998;29:415-421.
2. American Heart Association. 2002 Heart and Stroke Statistical Update. 2001.
3. Pulsinelli WA. Cerebrovascular diseases. Cecil Textbook of Medicine. 1996.
11/6/2015
TIA
• Underrecognized
• Underreported
• Undertreated
TIA Knowledge
• Among 10,112 participants
– 8.2% correctly related the definition of TIA
– 8.6% could identify a typical symptom
– Men, non-whites, and those with lower income
and fewer years of education were less likely to
be knowledgeable about TIA.
Johnston, et al, Neurology 2003
TIA Definition
• Resolution of acute neurological/stroke
deficits within 24 hours.
• No imagable acute ischemic stroke changes.
TIAs
• The majority of TIAs resolve within 60 minutes,
and most resolve within 30 minutes.
• Less than 15% chance of complete resolution of
symptoms if last >1 hour (Levy).
• NINDS IV t-PA trial data revealed only 2%
chance of complete symptom resolution @ 24
hours, for neurological symptoms/deficits that
didn’t completely resolve within 1 hour or rapidly
improve within 3 hours.
TIA Epidemiology
• >200,000 events per year (compared to >730,000
strokes per year).
• Approximately 10-20% of patients will experience
a stroke after a TIA within the first 90 days, and in
approx. 50% of these patients, the stroke occurs in
the first 24-48 hours.
• Factors associated with increased stroke risk:
advanced age, diabetes mellitus, symptoms more
than 10 minutes, weakness, and impaired speech.
Large artery atherothrombotic disease more likely
to present with a TIA before a stroke, versus other
etiologies.
TIA Epidemiology
• Several recent studies reveal a >10% stroke
risk in the 90 days after a TIA.
• The risk of stroke within the first 48 hours
after TIA is approximately 5% (greater than
MI risk after presenting with acute chest
pain syndrome).
• Blacks and men had higher stroke risk.
Event Risk Within 3 Months
After TIA
12.7%
Independent risk factors for stroke within 90 days
10.5%
after TIA:
• age > 60 years
• diabetes mellitus
• duration of episode greater than 10 min
• weakness and speech impairment with the episode
5%
in
48 h
Stroke
2.6%
Recurrent Cardiac
Event
TIA
Johnston SC, et al. JAMA. 2000;284:29012906.
2.6%
Death
TIA before Stroke by Subtype
• Large-artery atherothrombotic disease: 2550%.
• Cardioembolic sources: 10-30%.
• Small vessel/lacunar disease: 10-15%.
Symptomatic Internal Carotid Artery
Disease
•
•
•
•
NASCET Medical Arm Data (600 patients)
Two-day risk was 5.5%.
90-day ipsilateral stroke risk was 20%.
Degree of stenosis (>70% stenosis) didn’t confer
increased stroke risk.
• Infarct on brain imaging and presence of
intracranial major-artery disease doubled the early
stroke risk.
• Benefit from CEA declines rapidly over several
weeks, particularly in women (Oxford data).
Cumulative Risk of Stroke
Post-TIA (%)
Post-Stroke (%)
4–8
3 – 10
1 year
12 – 13
5 – 14
5 years
24 – 29
25 – 40
30 days
Sacco. Neurology. 1997;49(suppl 4):S39.
Feinberg et al. Stroke. 1994;25:1320.
TIA and ischemic stroke
pathophysiology are the same.
The only difference is transient
versus persistent neurological
deficits. Certainly, a TIA state is
a much better clinical state to
intervene and prevent a future
disabling stroke.
Risk Factors for First Ischemic
Stroke
Modifiable
(value established)
Nonmodifiable
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Age
Gender
Race/Ethnic
Heredity

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Adapted from Sacco RL. Neurology 1998;51(suppl
3):S27-S30.
Hypertension
Atrial fibrillation
Cigarette smoking
Hypercholesterolemia
Heavy alcohol use
Asymptomatic carotid
stenosis
Transient ischemic
attack
Stroke in Young Individuals
•
•
•
•
•
•
•
Clotting disorders
Migraine
Birth control pills
Illicit drug use
Arterial dissection
Patent foramen ovale
Autoimmune disorders (lupus)
TIA Evaluation
• Prompt evaluation and intervention is the
key.
• Most TIA patients should be admitted for
diagnostic evaluation and management
(Observation unit or equivalent); often
significant delay if done as outpatient.
• TIA and ischemic stroke diagnostic
evaluations should be the same.
Who should be admitted??
• Anyone with no prior/recent TIA/stroke
diagnostic workup; new suspected etiology
despite prior workup.
• Suspected large vessel (anterior or posterior
circulation) events.
• Most suspected lacunar/small vessel events,
particularly if no prior workup (? calm
before the storm).
• Recurrent/crescendo TIAs.
ABCD2 Score
• Age 60 or older
• Blood pressure >140/90
• Clinical
- Unilateral weakness
- Speech impairment
• Duration
- 60 minutes or more
- Less than 60 minutes
• Diabetes
1 point
1 point
2 points
1 point
2 points
1 point
1 point
ABCD2 Score
• Score 4 or greater – admit to hospital
(moderate-high stroke risk).
• Score predicted risk similarly among all
ethnic backgrounds.
• Best predictor of 2, 7, and 90 day stroke risk
among validated scales.
Inpatient TIA Management
• Neurochecks; follow blood pressures.
• ? Cardiac telemetry (paroxysmal a. fib).
• ? Intravenous Heparin for suspected high
risk TIA sources, pending completion of
diagnostic evaluation.
• Diagnostic evaluation should be completed
within 24 hours; make decision regarding
admission or discharge at that point.
• Potential IV t-PA use for recurrent event
(acute ischemic stroke) while hospitalized.
Presumptive TIA/stroke etiology
determines optimal treatment, as
well as risk for recurrent events.
Stroke Subtypes and Incidence
Other
5%
Cryptogenic
30%
Ischaemic stroke
85%
Cardiogenic
embolism
20%
Hemorrhagic
stroke
15%
Atherosclerotic
cerebrovascular
disease
20%
Small vessel
disease
“lacunes”
25%
Albers et al. Chest 2004; 126 (3 Suppl): 438S–512S.
TIA BRAIN IMAGING
• Prior CT(brain) studies revealed a 15-20%
incidence of cerebral infarction in a vascular
territory related to the patient’s symptoms/deficits.
• Newer MRI(brain) studies, using diffusionweighted imaging (DWI), reveal approx. 30-50%
acute ischemic stroke findings, and about half of
these persisted on follow-up imaging. Best
correlated with prolonged TIA symptoms.
MRI Diffusion Imaging
• Distinguish new versus old ischemic areas.
• Distinguish new ischemic areas even with
clinical TIA.
• Differentiate stroke etiology (small vessel
vs. large vessel; embolic sources).
Acute Embolic Strokes
Acute Ischemic Stroke