Can we safely discharge TIA patients?

1. Can we safely discharge TIA patients? Louis Muller EM Registrar January 2010

2. Objectives • Define TIA. Change in Definition. • How is TIA dx? • How should TIA be evaluated in the ED? • How should these patients be treated in ED? • What is their correct disposition?

3. Discharging TIA patients • Challenges the EP face in the ED. • Which patients are at highest short term risk of stroke? • Who do we admit?

4. TIA – Background • Common – 68 per 100 000 • Over 2.5 million cases EDs/year • Estimated 800 000 stroke/yr in US • 15 – 30% preceded by TIA • How do we measure outcome? • stroke • other cardiovascular events (MI and sudden death)

6. New definition - TIA • Tissue-based rather than time-based • Recognises TIA as a pathophysiological entity • TIA defined by symptomatic ischaemia, with no evidence of infarction. • Pt’s with brief Sx duration, but do not receive a detailed diagnostic evaluation – TIA or Stroke?? ACUTE NEUROVASCULAR SYNDROME

7. Why change in def? • Studies from many groups have shown The arbitrary time threshold was too broad, because 30 – 50 % of classically def. TIA’s shows brain injury on DW (MRI)

8. TIA is to stroke as . . . • DVT is to PE • Unstable Angina is to myocardial infarction • Near syncope is to syncope • TIA and stroke are different manifestations of the same disease

9. How do we Dx TIA • History – Abrupt onset – Deficits fall within a vascular territory (Ant vs Post) – Different body part symptoms occur simultaneously – Duration of symptoms Positive vs. Negative • TIA usually is a negative symptom - something that is absent –weakness, aphasia, numbness • Seizure (and migraine) is usually a positive symptom - something that is abnormally present –tingling, “pins & needles”, involuntary movements

10. Dx TIA • Physical examination • Fundi • Neck – bruit • Cardiac – murmurs, rhythm • Full neurological exam

11. Symptomsnot acceptable for diagnosis of TIA • Non-focal symptoms • LOC • Dizziness • Generalized weakness • Mental confusion • Loss of vision if associated with reduced LOC • Sphincter incontinence

12. Symptomsnot acceptable as evidence of TIA • Any of following IF ISOLATED findings: • Vertigo (usually) or loss of balance • Diplopia, dysphagia or tinnitus • Sensory Sx confined to part of one limb or the face • Amnesia • Drop attacks • Isolated dysarthria

13. Differential diagnoses - TIA • Stroke • Migraine • Cranial artery dissection • Seizure • Mass lesion (SDH, abscess, tumor) • Transient global amnesia • Metabolic abnormalities • Rare – vasculitis, AVM • Children – either a heart or vascular problem

14. TIA Dx – What now? • What is short term risk of stroke? • Do we admit the pt? • How quickly out pt – work up? • How reliable is pt? • Does Pt have PCP? • What Rx can we initiate in ED?

15. TIA – Risk of Stroke? • What is the short-term likelihood of stroke & can we risk stratify patients? • When will these strokes occur? • Who will it occur in?

16. When will these strokes occur? • 25-30% will stroke within 5 years • ~ 10% will stroke within 3 months • ~ 5% will stroke within 2 days (125,000 of them will have a stroke in the next 48hours)

18. Who will these strokes occur in? • We need to identify risk factors for stroke after TIA. • 3 Broad strategies been studied as predictors. • Clinical risk scores (pt charac.+ neurology) • DW (MRI) • Vascular imaging (id stenosis)

19. Clinical risk scores • California (2000 Johnstone et al) • 16 hospitals over 1year (1707 pt’s) • 5 variables independently predictive • 90 day stroke risk • ABCD (2005 Rothwell et al) • 209 pt’s ( validated 190pts) • 5 predictive variables • 7 day stroke risk • ABCD2 (authors combined their data) • to derive a unified optimal risk score • validation was done in 4 indep. populations (2893 pt) • 2, 7, 90 day stroke risk

23. Clinical risk scores - limitation • The ability to ID – “treatment-urgent” patients, ie • Carotid stenosis requiring revascularization • Cardioembolism needs anticoag not been established. • One study (Cucchiara et al 2006) 117 pts the ABCD score performed poorly in ID “high risk” patients • Risk scores supplement but don’t replace clinical judgment.

24. Can imaging help with risk stratification?

25. Can imaging help with risk stratification? • Benefit in patients with low ABCD2? • Limitations to MRI use • Availability • Cost • Patient tolerance • Time • CUS and echo use in risk stratification – limited data.

26. Acute Management of TIA • Goal – to optimize potentially compromised cerebral blood flow • Positioning head of bed flat • Permissive hypertension • IV fluids • Antiplatelet therapy • IST and CAST – aspirin reduce recurrent ischemic stroke by 7 per 1000 and mortality by a further 4 per 1000 pts treated • Anticoagulation early in TIA – limited data • Early initiation of statin therapy during hospitalization has been shown to increase long-term compliance and may have a potential neuroprotectant effect

27. AHA/ASA Guidelines for antiplatelet Tx for stroke prevention • Both recommend the use of antiplatelet therapy for patients who have a noncardioembolic TIA • Aspirin at a dosage of 50 to 325 mg/d; the combination of aspirin, 25 mg, and ER-DP, 200 mg twice daily; and clopidogrel at a dose of 75 mg/d are all considered acceptable • Initial therapy with aspirin and ER-DP is suggested instead of aspirin alone • clopidogrel may be considered instead of aspirin alone • The combination of aspirin and clopidogrel is not routinely recommended • The AHA/ASA guidelines emphasize that the selection of antiplatelet agents should be individualized on the basis of patient characteristics,such as risk profile and tolerance of side effects

28. TIA – Who do we admit? • Options Admit (medicine/neurology) vs Urgent-access specialized TIA clinics vs ED observation unit (EDOU) vs Outpatient

29. TIA – Who do we admit? • Potential benefits of admission • If stroke develops, could lyse faster • Work-up can often be accomplished faster • Initiate treatment sooner Carotid intervention for stenosis Heparin for atrial fibrillation • Observation if there is diagnostic uncertainty • Medico-legal issues • PREVENT A STROKE

30. TIA – Who do we admit? • Most patients with TIA will not stroke in short term • Benefit of hospitalization uncertain (limited clinical data) • Poisson et al (2007) • Prospective surveillance study • 5yr/ 552pts – 69% admitted • Risk of stroke at 30d • 2% hospitalized • 7% discharged • Considerable expense and resource consumption ( vs long term care of stroke pt)

31. Urgent access TIA clinic • Outpatient evaluation <24 -48hrs in specialized TIA clinic. • EXPRESS study (Rothwell et al) • Rapid-access TIA clinic vs std outpatient eval. • This included IMMEDIATE Dx testing and Rx initiation (1278 pts) • 2 phases (Before vs After) • Stroke rate at 90d decreased from 10.3% to 2.1% • SOS- TIA Trial

33. ED observation units • Accelerated diagnostic protocol applied • Idea very similar to Mx of low-intermediate risk Chest pain pts. (Chest pain unit ) • 2007 Ross et al – • Prospective randomized study • Inpatient(control) vs EDOU(TIA ADP) • CT,ECG,bloods,serial clinical exams • Neurology consult, CUS, Echo, cardiac monitoring • Length of stay 61 vs 26hrs • Lower 90d total direct costs • Comparable 90d clinical outcomes • Promising alternative, but requires commitment of resources.

34. Admission recommendation 2006 – National Stroke Association • Consider – 1st TIA <24-48hrs • Generally recommended • crescendo TIA’s • duration Sx > 1hr • Sx Carotid stenosis > 50% • known cardiac source of embolus • known hypercoagulable state • Appropriate ABCD2 score

36. Diagnostic Recommendations

37. Diagnostic recommendations

38. Diagnostic recommendations

39. Current practice at UCT/US? • GSH • C15 -stroke team via medicine (?GFJ & NSH) ABCD2 >4 admit (pending bed availability,6 or more definitely) CUS + imaging <24hrs ABCD2 <2 Workup as outpt <48hrs At least CUS • Neurology • Used to give ASA / simvastatin/ control DM, BP Out pt workup • Now ABCD2 (high – stroke bed low – workup within 1-2 weeks • Attitude changed over last year. They want to know about all pts. More urgent management

40. Current practice at UCT/US? • Tygerberg • Neurology • Admit all patients • Do not really use risk stratification • Same day CUS • CTA/MRA on ind. Cases • Obs 2-3 days • Very few as out patients

41. Summary • Neuroimaging studies altered the understanding of TIA pathophysiology • Change in definition • TIA = high short-term risk of early stroke • Risk stratify • New recommendations – greater urgency (same urgency as pts with Unstable Angina?) • Further research needed to optimize risk stratification (+- neuroimaging)

42. References • Stroke 2009;40;2276-2293 – May 2009 • Rothwell et al, Express study.Lancet.2007;370:1432 – 1442 • Cucchiara BL et al,Is the ABCD score useful for risk stratification op patients with acute TIA? Stroke 2006;37:1710-1714 • Ross,M et al . Management of TIA in the Twenty-First Century. Emerg med Clin N Am 27( 2009)51-69 • Edlow,JA. Current cotroversies in the Management of TIA, Chicago Scientific Assembly • Cucchiara BL et al. Transient Ischemic Attack: risk stratification and Treatment.Annals of Emergency Medicine vol 52 no2 (August 2008) • Edlow, JA. Rapid TIA patient evaluation and treatment. www.ferne.org • Stead,L. Suspected TIA patients in the Emergency department: The Mayo Clinic appearance. www.ferne.org