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Evaluation and Management of Transient Ischemic Attacks


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Evaluation and Management of Transient Ischemic Attacks

  1. 1. 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
  2. 2. Disclosures <ul><li>Boehringer Ingelheim </li></ul><ul><li>Genentech </li></ul><ul><li>AGA Medical Corp </li></ul>
  3. 3. OBJECTIVES <ul><li>Discuss the importance of TIA and future stroke risk. </li></ul><ul><li>Discuss optimal TIA evaluation and management. </li></ul><ul><li>Briefly discuss future stroke prevention, from both an antiplatelet/anticoagulant therapy and risk factor management standpoint. </li></ul>
  4. 4. Stroke in the US <ul><li>730,000 new or recurrent strokes each year 1 </li></ul><ul><li>167,366 deaths in 1999 (1 of every 14.3 deaths) 2 </li></ul><ul><li>4,600,000 stroke survivors alive today 2 </li></ul><ul><li>Origin of strokes 3 </li></ul><ul><ul><li>80% ischemic </li></ul></ul><ul><ul><li>20% hemorrhagic </li></ul></ul>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.
  5. 5. TIA <ul><li>Underrecognized </li></ul><ul><li>Underreported </li></ul><ul><li>Undertreated </li></ul>
  6. 6. TIA Knowledge <ul><li>Among 10,112 participants </li></ul><ul><ul><li>8.2% correctly related the definition of TIA </li></ul></ul><ul><ul><li>8.6% could identify a typical symptom </li></ul></ul><ul><ul><li>Men, non-whites, and those with lower income and fewer years of education were less likely to be knowledgeable about TIA. </li></ul></ul><ul><ul><li>Johnston, et al, Neurology 2003 </li></ul></ul>
  7. 7. TIA Definition <ul><li>Resolution of acute neurological/stroke deficits within 24 hours. </li></ul><ul><li>No imagable acute ischemic stroke changes. </li></ul>
  8. 8. TIAs <ul><li>The majority of TIAs resolve within 60 minutes, and most resolve within 30 minutes. </li></ul><ul><li>Less than 15% chance of complete resolution of symptoms if last >1 hour (Levy). </li></ul><ul><li>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. </li></ul>
  9. 11. TIA Epidemiology <ul><li>>200,000 events per year (compared to >730,000 strokes per year). </li></ul><ul><li>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. </li></ul><ul><li>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. </li></ul>
  10. 12. TIA Epidemiology <ul><li>Several recent studies reveal a >10% stroke risk in the 90 days after a TIA. </li></ul><ul><li>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). </li></ul><ul><li>Blacks and men had higher stroke risk. </li></ul>
  11. 13. 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 <ul><li>age > 60 years </li></ul><ul><li>diabetes mellitus </li></ul><ul><li>duration of episode greater than 10 min </li></ul><ul><li>weakness and speech impairment with the episode </li></ul>Independent risk factors for stroke within 90 days after TIA:
  12. 14. TIA before Stroke by Subtype <ul><li>Large-artery atherothrombotic disease: 25-50%. </li></ul><ul><li>Cardioembolic sources: 10-30%. </li></ul><ul><li>Small vessel/lacunar disease: 10-15%. </li></ul>
  13. 15. Symptomatic Internal Carotid Artery Disease <ul><li>NASCET Medical Arm Data (600 patients) </li></ul><ul><li>Two-day risk was 5.5%. </li></ul><ul><li>90-day ipsilateral stroke risk was 20%. </li></ul><ul><li>Degree of stenosis (>70% stenosis) didn’t confer increased stroke risk. </li></ul><ul><li>Infarct on brain imaging and presence of intracranial major-artery disease doubled the early stroke risk. </li></ul><ul><li>Benefit from CEA declines rapidly over several weeks, particularly in women (Oxford data). </li></ul>
  14. 16. 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.
  15. 17. 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.
  16. 18. Risk Factors for First Ischemic Stroke Adapted from Sacco RL. Neurology 1998;51(suppl 3):S27-S30. <ul><ul><li>Hypertension </li></ul></ul><ul><ul><li>Atrial fibrillation </li></ul></ul><ul><ul><li>Cigarette smoking </li></ul></ul><ul><ul><li>Hypercholesterolemia </li></ul></ul><ul><ul><li>Heavy alcohol use </li></ul></ul><ul><ul><li>Asymptomatic carotid stenosis </li></ul></ul><ul><ul><li>Transient ischemic attack </li></ul></ul>Nonmodifiable Modifiable (value established) <ul><ul><li>Age </li></ul></ul><ul><ul><li>Gender </li></ul></ul><ul><ul><li>Race/Ethnic </li></ul></ul><ul><ul><li>Heredity </li></ul></ul>
  17. 19. Stroke in Young Individuals <ul><li>Clotting disorders </li></ul><ul><li>Migraine </li></ul><ul><li>Birth control pills </li></ul><ul><li>Illicit drug use </li></ul><ul><li>Arterial dissection </li></ul><ul><li>Patent foramen ovale </li></ul><ul><li>Autoimmune disorders (lupus) </li></ul>
  18. 20. TIA Evaluation <ul><li>Prompt evaluation and intervention is the key. </li></ul><ul><li>Most TIA patients should be admitted for diagnostic evaluation and management (Observation unit or equivalent); often significant delay if done as outpatient. </li></ul><ul><li>TIA and ischemic stroke diagnostic evaluations should be the same . </li></ul>
  19. 21. Who should be admitted?? <ul><li>Anyone with no prior/recent TIA/stroke diagnostic workup; new suspected etiology despite prior workup. </li></ul><ul><li>Suspected large vessel (anterior or posterior circulation) events. </li></ul><ul><li>Most suspected lacunar/small vessel events, particularly if no prior workup (? calm before the storm). </li></ul><ul><li>Recurrent/crescendo TIAs. </li></ul>
  20. 22. ABCD2 Score <ul><li>Age 60 or older 1 point </li></ul><ul><li>Blood pressure > 140/90 1 point </li></ul><ul><li>Clinical </li></ul><ul><li>- Unilateral weakness 2 points </li></ul><ul><li>- Speech impairment 1 point </li></ul><ul><li>Duration </li></ul><ul><li>- 60 minutes or more 2 points </li></ul><ul><li>- Less than 60 minutes 1 point </li></ul><ul><li>Diabetes 1 point </li></ul>
  21. 24. ABCD2 Score <ul><li>Score 4 or greater – admit to hospital (moderate-high stroke risk). </li></ul><ul><li>Score predicted risk similarly among all ethnic backgrounds. </li></ul><ul><li>Best predictor of 2, 7, and 90 day stroke risk among validated scales. </li></ul>
  22. 25. Inpatient TIA Management <ul><li>Neurochecks; follow blood pressures. </li></ul><ul><li>? Cardiac telemetry (paroxysmal a. fib). </li></ul><ul><li>? Intravenous Heparin for suspected high risk TIA sources, pending completion of diagnostic evaluation. </li></ul><ul><li>Diagnostic evaluation should be completed within 24 hours; make decision regarding admission or discharge at that point. </li></ul><ul><li>Potential IV t-PA use for recurrent event (acute ischemic stroke) while hospitalized. </li></ul>
  23. 26. Presumptive TIA/stroke etiology determines optimal treatment, as well as risk for recurrent events.
  24. 27. 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%
  25. 28. TIA BRAIN IMAGING <ul><li>Prior CT(brain) studies revealed a 15-20% incidence of cerebral infarction in a vascular territory related to the patient’s symptoms/deficits. </li></ul><ul><li>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. </li></ul>
  26. 29. MRI Diffusion Imaging <ul><li>Distinguish new versus old ischemic areas. </li></ul><ul><li>Distinguish new ischemic areas even with clinical TIA. </li></ul><ul><li>Differentiate stroke etiology (small vessel vs. large vessel; embolic sources). </li></ul>
  27. 30. Acute Embolic Strokes
  28. 31. Acute Ischemic Stroke