Stroke Prevention Strategies
following TIA
David Williams
Dept of Geriatric and Stroke Medicine
Beaumont Hospital/RCSI
The Society for Acute Medicine, Spring Meeting, Radisson Blu Hotel, Dublin 3-4 May 2012
Advances in Stroke Care
Oxford Textbook of Medicine, 1983
“ There is probably little that medical treatment can do to alter the
immediate prognosis of stroke. Both fibrinolytic drugs and anticoagulation increase the risk of intracranial bleeding and should
usually not be used.”
Research advances
1993
1994
1997
2003
2004
2005
2007
2009
Evidence for Stroke Unit benefits
Carotid Endarterectomy
Aspirin to prevent early recurrent stroke
Alteplase licensed for treatment acute ischaemic stroke, NICE
recommended 2007
Outpatient therapy services
Early supported discharge services
Hemicraniectomy for malignant MCA infarction
? More protection for patients with atrial fibrillation
Case Presentation
A 55-yr old patient presents 5-days following an
episode of visual loss in his left eye, followed by
right-sided weakness and speech disturbance
lasting 10 minutes. BP 130/80.He has made a
complete recovery and has driven himself to his
GP surgery to ask if he can return to work.
TIA - Definition
An acute loss of focal brain or monocular function
with symptoms lasting less than 24-hrs and
which is thought to be caused by inadequate
cerebral or ocular blood supply as a result of
arterial thrombosis, low flow or embolism
associated with arterial, cardiac or
haematological disease (Hatano, 1976)
Imaging TIAs
TIA - Definition
An acute loss of focal brain or monocular function
with symptoms lasting less than 24-hrs and
which is thought to be caused by inadequate
cerebral or ocular blood supply as a result of
arterial thrombosis, low flow or embolism
associated with arterial, cardiac or
haematological disease (Hatano, 1976)
‘Transient episode of neurological dysfunction
caused by focal neurological symptoms caused
by focal brain, spinal cord or retinal ischaemia
without acute infarction’(Easton, 2009)
Diagnosing TIAs
• Transient Ischaemic attack(TIA) is a sudden loss of focal
neurological deficit which resolves completely within
24hrs.
• Amaurosis Fugax, an embolic form of TIA in the carotid
territory , is painless transient monocular blindness,
described as a curtain, shade or mist descending over
the eye.
• Diagnosis of TIA is based entirely on history rather than
brain imaging.
• Risk of a recurrent event after a TIA is highest in the first
month (risk of 8-10% at 7 days and 11-15% at 30 days)
Assessing symptoms
• Onset-Sudden. Insidious onset of symptoms is unlikely to be a TIA
• Intensity-Symptoms maximal at onset. Gradual progression
suggest migraine, demyelination, or tumour. Multiple and intermittent
symptoms are atypical.
• Focal symptoms
– Carotid Artery Territory symptoms include amarosis fugax,
contralateral weakness or numbness, dysphasia, and
hemianopia.
– Vertebrobasilar Territory symptoms include ataxia, vertigo,
dysarthria, diploplia, hemianopia, and bilateral visual
loss(isolated dizziness, lightheadness or vertigo is rare)
• Loss of consciousness(syncope) is not a TIA
• Duration-Most TIAs last 5-15mins.
• Recognisable pattern- Symptoms corresponding to a recognised
neurological territory are supportive of a TIA.
• Headache-severe headache or eye pain is not a feature of TIA
TIA Mimics
•
•
•
•
•
•
•
•
Migraine
Partial Seizure
Syncope
Vestibular Disorders
Neuropathy and Radiculopathy
Ocular Disorders
Hypoglycaemia
CNS Tumours
Symptoms that don’t suggest a TIA
•
•
•
•
•
•
•
•
Loss of consciousness
Acute Confusion
Seizure
Loss of Memory
Isolated dizziness, lightheadness or vertigo
Gradual progression of symptoms
Multiple recurrent symptoms
Severe Headache
TIA-a warning sign
• 30-40% of patients with ischaemic stroke
have had an earlier transient ischaemic
attack or minor stroke
• 90-day risk of subsequent stroke is as high
as 10.5%, with almost half of these
occurring within the first 2 days
Timing of TIA preceding ischaemic stroke
35
4 studies
Percentage of patients
30
2416 patients with ischaemic stroke
25
549 (23%) reported preceding TIA
20
15
10
5
0
0
1
2
Neurology 2005; 64: 817-20.
3
4
5
6
7
Days
8
9
10
11
12
13
14
Early review is essential
• But >30% of patients
referred to the clinic have
another diagnosis…..
• Putting stress on the
system….
• How can risk be stratified?
TIA = ABCD2
ABCD2
Symptom
Score
Age > 60 years
1 point
Blood pressure > 140/80
1 point
Clinical (neurological deficit) 2 points for hemiparesis
1 point for speech problem without weakness
Duration
2 points for >60 minutes
1 point for 10-60 min
Diabetes
1 point
Maximal score is 7.
Rothwell et al, Lancet. 2007;369:283-92
ABCD2 Stroke Risk
48 hours
1 week
3 months
0-3
Low risk
1%
1%
3%
4-5
Mod. risk
4%
6%
10%
6-7
High Risk
8%
12%
18%
TIAS with a score of 5 or greater
should have immediate Ix and Tx (within 24 h if possible).
ABCD2 scoring
• Based on observational studies(Patients
received treatment which may have
contaminated the reported risks).
• Predictive of disabling stroke(Not any
stroke).
• Poor inter-rater reliability(40% produced
scores discrepant from those at a central
co-ordinating centre).
Low ABCD2 Scores and Stroke risk
•
•
•
Amarenco, Pierre; Labreuche, Julien; Lavallee, Philippa
Stroke. 43(3):863-865, March 2012.
SOS-TIA study previously reported
that I in 5 with a TIA and ABCD2
score<4 had a major finding requiring
immediate medical decision
making(Symptomatic ipsilateral carotid
stenosis, severe intracranial stenosis,
atrial fibrillation or other cardiac source
of embolism)
90-day stroke rate was similar in
patients with ABCD2≥4 (3.4%)and
those with ABCD2 <4 and criteria for
emergency treatment(3.9%) but low in
patients with ABCD2 <4 and no criteria
for emergency treatment(0.4%) .
In patients with ABCD2≥4, 90-day risk
of stroke was 4.6% in those with
emergency criteria, compared with
3.0% in those without such criteria.
2
Addition of Brain Infarction to the
predictive Score
•
•
•
Patients with high ABCD2 scores
are more likely to have brain
infarction on diffusion-weighted
imaging(DWI).
Analysis of 4574 patients with
WHO defined time-based TIA and
available imaging(MRI/CT)
suggests that incorporation of
infarction(3 pts) in the ABCD2I
score improved the predictive
power for stroke (pooled AUC
increased from 0.66 for ABCD2 to
0.78 ABCD2 I).
Pooled C-statistic was 0.8(95%CI
0.74-0.86) for predicting stroke
risk at 90 days.
Giles et al Stroke 2010;41:1907-1913
ABCD3I
•
•
Inclusion of carotid stenosis(2
pts) and abnormal DWI(2pts)
in ABCD3-I improved the 90day-net reclassification by 39%
compared with ABCD2
Pooled C-statistic was
0.79(95%CI 0.66-0.9) in the
derivation cohort and
0.71(95%CI, 0.64-0.77) in the
validation cohort for predicting
stroke risk at 90 days.
Merwick et al. Lancet Neurol.2010;9:1060-69
ABCD2I
ABCD2
ABCD3I
Investigation and Management of
TIAs
Management and Investigations
• Check Pulse, ECG, Neurological Examination
• FBC, U&E,Fasting Glucose and Total
Cholesterol
• Urgent Carotid Doppler-Those with carotid
circulation TIA who are fit for surgical
intervention
• ?Prognostic Score-NICE recommends that
patients with an ADCD2 score≥4 should be
assessed and investigated within 24hrs.
• No Driving for 30 days
Secondary Preventive Therapy
• Antithrombotic therapy
Aspirin+dipyridamole
Clopidogrel if intolerant of aspirin
• Anticoagulation (following imaging) in Atrial
Fibrillation
• Blood Pressure Control (according to National
guidelines)
• Statin (if total chol>3.5mmol/l or LDL
chol>2.5mmol/l)
• Other secondary preventive measures-Smoking
cessation, exercise, screening for Diabetes
Endarterectomy should be
performed within 2 weeks of the
patient’s last symptoms
Hypertension
BP lowering regimen
(perindopril +/indapamide) reduced
the risk of stroke among
hypertensive and nonhypertensive individuals
with a history of
stroke/TIA
Lancet 2001;358:1033-41
Treatment with atorvastatin
80mg daily reduced stroke
risk in patients with recent
stroke or TIA and no known
coronary heart disease by
16% versus placebo over 4.9
years of follow-up
Amarenco p,et al NEJM 2006;355:549-59
Benefits of combined multiple approaches to secondary
prevention of vascular events after stroke
Hackham et al, Stroke 2007, 38:1881085
Fig The proportions of patients seen in the transient ischaemic attack and stroke clinic with a definite ischaemic
cerebrovascular event who had started taking an antithrombotic drug (antiplatelet or anticoagulant) between their
event and being assessed in the clinic.
Kerr, E. et al. BMJ 2010;341:c3265
EXPRESS
•
•
•
•
Phase 1
Appointment-based
Delays in receiving referrals
and contacting patients
Treatment recommendations
sent to referring primary care
physician
Treatment
•
•
Phase 2
No appointment
Treatment initiated following
confirmation of diagnosis
– Aspirin/Clopidogrel/both in
high risk patients
– Simvastatin
– BP lowering(unless
SBP<130mmHg)
– Anticoagulation as required
Rothwell,P et al Lancet 2007;370:1432-42
EXPRESS
•
•
•
Median delay to assessment
fell from 3(IQR 2-5) days in
phase 1 to <1(0-3) day in
phase 2.
Median delay to first
prescription fell from 20(8-53)
days in phase 1 to 1(0-3) day
in phase 2.
90-day risk of recurrent stroke
fell from 10.3% in phase 1 to
2.1% in phase 2.
Rothwell,P et al Lancet 2007;370:1432-42
SOS-TIA
• 24-hr access
• Assessment of 1085
patients within 4hrs of
admission
• 74% patients sent home
within 24hrs
• 90-day stroke rate was
1.24% (95% CI 0.722.12) vs rate predicted
from ABCD2 of 5.96%.
When to assess?
• NICE-Admit those with ABCD2 ≥4 and evaluate
those with ABCD2 <4 within 7 days.
• ?Evaluate all patients within 24hrs regardless of
ABCD2 to detect patients requiring immediate
medical decision-making.
• ?Observe for≥24hrs those with ABCD2 ≥4.
Case Presentation
• A 55-yr old patient presents 5-days following an
episode of visual loss in his left eye, followed by
right-sided weakness and speech disturbance
lasting 10 minutes. BP 130/80.He has made a
complete recovery and has driven himself to his
GP surgery to ask if he can return to work.
• ABCD2= 3
• ECG-NSR
Carotid Duplex-70-90% stenosis LICA
Summary
• Most TIAs last only a few minutes
• Outcome (without intervention):
-25-30% will develop a stroke within 5 years
-10% will develop a stroke within 3 months
• TIA is to stroke as
-DVT is to PE
-Angina is to MI
• Rapid Assessment required(?AMAU)
Why Do Accidents Occur?