Evaluation and Management of Transient Ischemic AttacksPresentation 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. Hershey Medical Center January 8, 2009
AGA Medical Corp
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 year 1
167,366 deaths in 1999 (1 of every 14.3 deaths) 2
4,600,000 stroke survivors alive today 2
Origin of strokes 3
10/18/10 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.
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
Resolution of acute neurological/stroke deficits within 24 hours.
No imagable acute ischemic stroke changes.
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.
>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.
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 Johnston SC, et al. JAMA . 2000;284:2901 2906. Recurrent TIA Cardiac Event Stroke Death Event Rate 12.7% 2.6% 2.6% 10.5% 5% in 48 h
age > 60 years
duration of episode greater than 10 min
weakness and speech impairment with the episode
Independent risk factors for stroke within 90 days after TIA:
TIA before Stroke by Subtype
Large-artery atherothrombotic disease: 25-50%.
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 (%) 4 – 8 12 – 13 24 – 29 30 days 1 year 5 years Post-Stroke (%) 3 – 10 5 – 14 25 – 40 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 Adapted from Sacco RL. Neurology 1998;51(suppl 3):S27-S30.
Heavy alcohol use
Asymptomatic carotid stenosis
Transient ischemic attack
Nonmodifiable Modifiable (value established)
Stroke in Young Individuals
Birth control pills
Illicit drug use
Patent foramen ovale
Autoimmune disorders (lupus)
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).
Age 60 or older 1 point
Blood pressure > 140/90 1 point
- Unilateral weakness 2 points
- Speech impairment 1 point
- 60 minutes or more 2 points
- Less than 60 minutes 1 point
Diabetes 1 point
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 Albers et al. Chest 2004; 126 (3 Suppl): 438S –512 S. Ischaemic stroke 85% Hemorrhagic stroke 15% Other 5% Cryptogenic 30% Cardiogenic embolism 20% Small vessel disease “ lacunes” 25% Atherosclerotic cerebrovascular disease 20%
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 diffusion-weighted 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).