High Risk TIA: Identification and Management

1. High Risk TIA:Identification and Management April 2008 Information was produced and/or compiled by the Alberta Provincial Stroke Strategy and written permission is required prior to reprinting any of the material located within this document. 04/08:04/09[R]

2. High Risk TIA: Identification and Management Learning Objectives: Upon completion of this session, participants will be able to: 1. Identify clinical predictors of stroke following a transient ischemic attack 2. Describe how neurovascular imaging may assist to identify those patients at increased risk of stroke following a transient ischemic attack. 3. Describe the appropriate management of a high risk TIA patient

3. What is a TIA? Definition: Focal neurological deficit lasting < 24 hr Proposed tissue based definition: Rapidly resolving neurologic symptoms, typically lasting <1 hour, with no evidence of infarction on MRI (DWI) (Albers et al. New Engl J Med; 2002; 347: 1713-1716) • 40% - 60% of TIA patients have ischemic injury on DWI (Ay et al. CerebrovascDis; 2002; 14: 177-186)

4. Stroke Risk Risk of stroke following a TIA is high: • 10-20% within 90 days • 50% of these within the first 48 hours 15-20% of stroke patients have a preceding TIA Golden Opportunity for Stroke Prevention!

5. TIA Prognosis TIA Review. Johnston C. Speech, motor, >10 min, age >60, diabetes

7. TIA Prognosis Speech, motor, >10 min, age >60, diabetes 9.5% at 90 days 14.5% at 1 year

8. Stroke Risk Gladstone D et al. CMAJ. 2004 Mar 30;170(7):1099-104. Speech, motor, >10 min, age >60, diabetes

9. Outcomes after TIAGladstone D et al. CMAJ. 2004 Mar 30;170(7):1099-104. 18% 3 month readmission rate after TIA Speech, motor, >10 min, age >60, diabetes

10. Are all TIA patients at risk of early stroke? Is it cost effective to admit all TIA patients to hospital?

11. Is it cost effective to admit all TIA patients to hospital? NO What is the cost of admitting patients with a TIA to hospital? Gordon Gubitz, Stephen Phillips, Victoria Dweyer The average cost of in-patient management of TIAs was $328,000 (Can), of which 95% was attributed to the cost of hospitalization alone. If hospitalization of patients with TIA could be reduced, significant cost-savings could be realized. Cerebrovascular Diseases 1999; 9: 210-214

12. Is it cost effective to admit all TIA patients to hospital?NO • Cost utility analysis of 24 hour TIA (based on higher likelihood of tPA) • The overall cost-effectiveness ratio was $55,044 per quality-adjusted life year • For patients with higher risk of stroke, admission was cost-effective Neurology 2005; 65: 1799-1801

13. We need a strategy to identify those TIA patients at highest risk

14. High Risk TIA: Clinical Predictors California Score: Predict 90 day stroke risk Identified 5 factors associated with high stroke risk • Age > 60 • Diabetes • Duration > 10 min • Weakness • Speech impairment Risk: 0% if none of the above factors 34% if had all 5 factors Johnston et al. JAMA; 2000; 284: 2901-2906

15. Clinical Predictors of High Risk TIAs Johnston CS et al. JAMA 2000; 284: 2901-6 OR CI p value Age >60 1.8 1.3-4.2 0.005 DM 2.0 1.4-2.9 0.001 >10 min 2.3 1.3-4.2 0.005 Weakness 1.9 1.4-2.6 0.001 Speech 1.5 1.1-2.1 0.01

16. High Risk TIA: Clinical PredictorsRecurrent Sensory = Benign Johnston C et al. Neurology 2004;62:2015-2020. Speech, motor, >10 min, age >60, diabetes Benign recurrent sensory attacks

17. High Risk TIA: Clinical Predictors ABCD Score: Predict 7 day stroke risk; Identified 4 areas associated with high risk Points • Age ≥ 60 1 • Blood pressure ≥ 140/90 1 • Clinical features • Unilateral weakness 2 • Speech disturbance without weakness 1 • Duration of symptoms • > 10 min < 59 min 1 • ≥ 60 min 2 Risk: Score < 5 = 0.4% risk; Score of 5 = 16% risk; Score of 6 = 35% risk Rothwell et al. Lancet; 2005; 366: 29-36

18. 1 1 2 1 0 2 1 0

20. High Risk TIA: Clinical PredictorsABCD2 Score - Refinement Lancet 2007; 369:283-92

21. ABCD2 Score

22. High Risk TIA: Clinical Predictors TIA Stroke Risk Assessment High Risk • Symptom onset < 48 hours with ABCD2 score ≥ 5 Medium Risk • Symptom onset > 48 hours with ABCD2 score ≥ 5 • Symptom onset < 48 hours with ABCD2 score < 5 Low Risk • System onset > 48 hours with ABCD2 score < 5 • Pure sensory deficit • Pure ataxia

23. Who is at risk? Scenario 1: 70 year old right-handed male with a history of diabetes and smoking is seen in the Emergency department after an episode three hours previously of transient aphasia and right hemiparesis lasting 65 minutes. This is his second episode in a week. He denies other neurologic symptoms. His examination is now completely normal, aside from a blood pressure of 160/80.

24. Age 70 (1) BP 160/80 (1) Weakness (2) 65 minutes (1) Diabetes (1) ABCD2 score = 7 Risk = 6% (2 day) 11% (7 day) 17% (30 day) 22% (90 day) Who is at risk?

25. High Risk TIA: Neurovascular Imaging • CT scan • MRI • Carotid Imaging

26. Neurovascular Imaging: CT Scan TIA population: 67% CT performed 4% (13/322) had evidence of infarct on CT Risk of stroke higher among those with a new infarct on head CT Stroke. 2003 Dec;34(12):2894-8.

27. Kaplan-Meier life-table analysis of survival free from stroke for patients with (dotted line) and without (solid line) new infarct on head CT 10% 38% stroke 2003 Dec;34(12):2894-8

28. Neurovascular Imaging: MRIKidwell C et al. Stroke 1999; 6:1174-1180. Couttts SB et al. Annals of Neurology 2005;57:848-854Krol A et al. Stroke 2005 40-60% of TIA pts have evidence of ischemic injury on DWI Factors predicting positive DWI: • Symptoms lasting > 1 hour • Motor deficits • Aphasia If TIA and DWI lesion - higher risk of subsequent stroke Even brief symptoms cause areas of permanent injury

29. Neurovascular Imaging: Carotid Imaging Imaging carotids is an important part of TIA evaluation • Carotid doppler ultrasound • CT angiography (CTA) • Magnetic resonance angiography There is an increased stroke risk with carotid artery disease

30. Once High Risk TIA Identified…then what? TIA MANAGEMENT

31. TIA Management There are 2 proven therapies to prevent the occurrence of stroke following TIA • Antiplatelet / Anticoagulation therapy • Carotid Endarterectomy

32. Antiplatelet/Anticoagulation Therapy Aspirin (50-325 mg/day) is first line treatment • If aspirin naïve- load with 160mg then 81 mg OD Options: Aspirin/extended release dipyridamole (Aggrenox) • 25mg/200mg BID Clopidogrel (Plavix) • 75 mg OD, consider loading with 300 mg No evidence to suggest any are superior or inferior to aspirin

33. Results 18 12 6 0 Cumulative Event Rate (Ischemic Stroke, Myocardial Infarction, Vascular Death, Rehospitalization due to Ischemic Event) Placebo+clopidogrel 6.4% RRR 1.03% ARR p=0.244 ASA+clopidogrel Cumulative event rate (%) On-Treatment Analysis: 9.6% RRR, 1.6% ARR, p=0.10 0 1 3 6 12 18 Months of follow-up * All patients received clopidogrel background therapy

34. Antiplatelet/Anticoagulation Therapy If cardioembolic source: • Long-term anticoagulation • INR acceptable range 2.0 – 3.0 (target 2.5)

35. TIA Management Carotid Endarterectomy

36. Carotid Endarterectomy If TIA due to ≥ 50% stenosis in extracranial carotid artery consider CEA Greatest benefit if surgery within 2 weeks Rothwell et al. Lancet; 2004; 363: 915-25

37. Carotid endarterectomy + medical management vs medical management alone: symptomatic patients 70% to 99% Carotid stenosis 50% to 69% carotid stenosis <50% Carotid stenosis asymptomatic patients > or =50% >or=60% NNT (Number-Needed-to-Treat) 8 to save 1 stroke at 2 years 20 to save 1 stroke at 2 years 67 to save 1 stroke at 2 years 83 to save 1 stroke at 2 years 48 to save 1 stroke at 2 years Carotid Artery Disease:Benefit of CEA Rothwell; The Lancet: vol 361. Jan 11, 2003

38. Early Carotid Surgery Better in 50-69% stenosis NNT 7 Rothwell PM et al. Stroke 2004;35:2855-2861.

39. Early Carotid Surgery Much Better >70% w/o near-occlusion Rothwell PM et al. Stroke 2004;35:2855-2861. NNT 3

40. Putting it all together High Risk TIA: Identification and Management

41. Case Scenarios #1 70 year old male Episode of right sided weakness and impaired speech lasting about 60 minutes yesterday Risk factors: hypertension, high cholesterol, ex-smoker Exam normal

42. Case Scenarios ABCD2 score? Time since onset? What is the risk? What are you going to do?

43. What is the risk? What are you going to do? • Low risk: investigate later • Medium risk: investigate soon • High risk: consider immediate investigation/admission • Very high risk: admission with aggressive treatment • Extreme risk: HELP!

44. ER Guidelines Vital signs (NIHSS) ECG CT scan Antiplatelet Carotid dopplar U/S

45. Case Scenarios 70 year old male Episode of right sided weakness and impaired speech yesterday Risk factor s: Hypertension, high cholesterol, ex-smoker Exam normal Carotid dopplers: 88% L ICA stenosis

46. Case Scenarios #2 55 year old healthy right-handed female is seen in a walk-in clinic after an episode of speech difficulty three hours previous lasting 15 minutes. She denies other neurological symptoms. Her examination is now completely normal aside for a blood pressure of 155/90.

47. Age 55 (0) BP 155/90 (1) Speech (1) 15 minutes (1) Diabetes (0) ABCD2 score = 3 Risk = 2% (2 day) 2% (7 day) 3% (30 day) 4% (90 day) Case Scenarios

48. Medium Risk Vital signs ECG CT scan Antiplatelet Carotid dopplar U/S Stroke Prevention Clinic referral

49. Questions?

50. High Risk TIA: Identification and Management Prepared by Carolyn Walker, RN, BN Education Coordinator Alberta Provincial Stroke Strategy March 2008 The APSS would like to acknowledge the contributions of Chinook, Capital and Calgary Health Regions for information used in the development of this presentation. April 7, 2008