Prevention of Ischemic Stroke

1. See Also
   1. CVA Management
   2. CVA Blood Pressure Control
   3. CVA Thrombolysis
   4. Ischemic CVA
   5. Transient Ischemic Attack
2. Indications
   1. Post-stroke antithrombotic therapy
   2. Atrial Fibrillation
      1. See Atrial Fibrillation Anticoagulation
3. Management: Short term prevention after Ischemic Stroke
   1. Aspirin 325 mg qd (first choice)
      1. CVA reduction of 1% with Aspirin by IST trial
      2. Effective in acute CVA therapy as well as prevention
   2. Low dose non-bolus Heparin (use is variable)
      1. Efficacy
         1. No evidence of benefit in CVA evolution
         2. Less hemorrhage than ASA by IST trial
         3. CVA reduction 1-2%
         4. Not indicated in most cases (risk without benefit)
            1. Stead (2004) Ann Emerg Med 44:540-2
      2. Dosing: Goal is PTT approximately twice normal
         1. Dose: 12 u/kg/h (NO bolus, by actual weight)
      3. Indications
         1. Cardioembolic CVA
         2. Aortic arch atheroma
      4. Contraindications
         1. CT Head shows bleeding
         2. Endocarditis on native valve thromboembolic CVA
   3. Antihypertensives
      1. See below
      2. See CVA Blood Pressure Control for acute control
      3. ACE Inhibitor with a Diuretic (e.g. Lisinopril/hctz)
         1. Start immediately after hyperacute period
         2. Significantly reduces recurrent CVA risk
            1. (2001) Lancet 358:1033-41
   4. Avoid potentially harmful interventions
      1. Heparin drip (Regular dose): Do Not Use
         1. No significant benefit by IST trial
         2. Risk of hemorrhage (especially with bolus)
      2. Low Molecular Weight Heparin
         1. Dose dependent CVA reduction by Hong Kong Study
         2. No benefit and high hemorrhage risk by TOAST study
      3. Emergent Anticoagulation not indicated
         1. Recurrent stroke in first 14 days is only 0.06%
         2. Can start in first 48 hours after CVA
         3. Bolus therapy is not indicated
      4. Do not lower Blood Pressure aggressively on first day
         1. See CVA Blood Pressure Control
      5. Ibuprofen
         1. Inactivates Aspirin positive effect
         2. Unclear if other NSAIDs also reduce benefit
4. Management: Long term prevention (Primary and Secondary Prevention)
   1. Anticoagulation after CVA or TIA
      1. See Anticoagulation in Atrial Fibrillation
      2. First-Line options
         1. Aspirin 50 to 325 mg qd or
         2. Clopidogrel (Plavix) if Aspirin intolerant or
         3. Aspirin 50 mg with Dipyridamole 400 mg (Aggrenox)
            1. Consider over Aspirin in highest risk patients
            2. Better efficacy over Aspirin alone
            3. No significant increased risk of bleeding
            4. Key disadvantage is price ($140 versus $1)
            5. References
               1. Diener (1996) J Neurol Sci 143:1-13
               2. Halkes (2006) Lancet 367:1665-73
      3. Avoid Warfarin (Coumadin) after nonembolic stroke
         1. No advantage over Aspirin to prevent recurrent CVA
         2. Warfarin is indicated in thromboembolic stroke
         3. Mohr (2001) N Engl J Med 345:1444-51
      4. Avoid combination of Aspirin and Clopidogrel
         1. Bleeding risk outweighed small vascular benefit
         2. Diener (2004) Lancet 364:331-7
   2. Other measures
      1. Control Hyperlipidemia
         1. Statin Drugs are preferred (e.g. Zocor)
         2. Goal LDL Cholesterol <70-100 mg/dl
      2. Control Hypertension to Blood Pressure <130/80 (after initial 24 hours)
         1. Hydrochlorothiazide (first line)
         2. ACE Inhibitors (in combination with Diuretic)
      3. Evaluate for reversible and modifiable disease
         1. See Transient Ischemic Attack
         2. Evaluate for Carotid Stenosis (>70% Occlusion)
            1. (1991) N Engl J Med 325:445-53
         3. Evaluate for arrhythmia (Atrial Fibrillation)
      4. Tobacco Cessation
         1. Risk of CVA is 50% higher in smokers
         2. Shinton (1999) BMJ 298:789-94
      5. Alcohol only in moderation
      6. Treat Coronary Artery Disease
      7. Optimize Diabetes Mellitus control
         1. Maintain Blood Pressure <130/80 (most important)
         2. Maintain fasting Glucose <126 mg/dl
      8. Maintain regular Exercise >30 minutes, >3 days/week
      9. Fish intake (1-4 servings per month)
         1. Lowered Ischemic Stroke risk by 40%
         2. He (2002) JAMA 288:3130-6
      10. Manage Major Depression (up to 20% of patients after stroke)
          1. Screen for and treat comorbid Major Depression
          2. Reduces mortality after Ischemic Stroke
          3. Consider Selective Serotonin Reuptake Inhibitor
          4. Jorge (2003) Am J Psychiatry 160:1823-9
   3. Ineffective measures
      1. Homocysteine modification with vitamins not effective
         1. Toole (2004) JAMA 291:565-75
5. References
   1. Lyden (2001) CMEA Medicine Lecture, San Diego
   2. Lyden (1998) CMEA Medicine Lecture, San Diego
   3. Adams (2007) Stroke 38(5): 1655-711
   4. Beauchamp (1999) Radiology 212(2):307-24
   5. Dickerson (2007) Am Fam Physician 76(3):382-8
   6. Ingall (2000) Postgrad Med 107(6):34-50
   7. Sacco (2000) Arch Intern Med 160(11):1579-82
   8. Solenski (2004) Am Fam Physician 69:1691-8