Do patients with a history of cerebral vascular accident (CVA) or stroke require anticoagulation therapy?

Anticoagulation for History of Stroke Alone

A history of stroke (CVA) alone does NOT require heparin infusion or any anticoagulation unless there is a specific indication such as atrial fibrillation, cardioembolic source, or acute venous thromboembolism. 1

Key Decision Points

For Noncardioembolic (Atherosclerotic) Stroke

• Antiplatelet therapy, NOT anticoagulation, is the standard treatment for patients with prior ischemic stroke or TIA without atrial fibrillation or other cardioembolic sources 1
• Recommended antiplatelet options include aspirin (75-100 mg daily), clopidogrel (75 mg daily), or aspirin/extended-release dipyridamole (25 mg/200 mg twice daily) 1
• Oral anticoagulation is NOT recommended over antiplatelet therapy for noncardioembolic stroke (Grade 1B evidence) 1

For Stroke WITH Atrial Fibrillation

• Oral anticoagulation IS required if the patient has atrial fibrillation (Grade 1A evidence) 1
• Direct oral anticoagulants (DOACs) are preferred over warfarin 1
• Anticoagulation should be initiated 2-14 days after the acute stroke event, depending on infarct size and hemorrhagic transformation risk 1, 2
• For TIA without infarction on imaging, oral anticoagulation can typically be initiated immediately 1

Critical Contraindications to Anticoagulation

• Cerebral amyloid angiopathy carries very high risk of recurrent intracranial hemorrhage and generally precludes anticoagulation 1
• Prior intracerebral hemorrhage (ICH), especially lobar ICH, is a strong contraindication to long-term anticoagulation 3
• For patients with prior deep hemispheric ICH and atrial fibrillation, withholding anticoagulation is still generally preferred (0.3 quality-adjusted life years gained) 3

Common Clinical Pitfalls

Acute Phase Management

• Parenteral anticoagulation (heparin infusion) within 48 hours of acute ischemic stroke increases hemorrhagic transformation risk and is NOT recommended 4, 5
• Low-dose subcutaneous heparin for DVT prophylaxis is appropriate for immobilized patients, but this is NOT therapeutic anticoagulation 1
• Prophylactic-dose LMWH or intermittent pneumatic compression should be used for VTE prevention in patients with restricted mobility, started 2-4 days after stroke 1, 2

Long-Term Management Algorithm

Determine the stroke mechanism:

1. Atherosclerotic/noncardioembolic stroke → Antiplatelet therapy only 1

   • No role for anticoagulation
   • Clopidogrel or aspirin/dipyridamole preferred over aspirin alone 1

2. Cardioembolic stroke (AF, severe LV dysfunction, anterior wall motion abnormality) → Oral anticoagulation required 1, 2

   • DOAC preferred over warfarin 1, 2
   • Stop antiplatelet therapy once therapeutic anticoagulation achieved 1

3. Stroke with recent carotid intervention → Depends on timing 1

   • Post-endarterectomy: OAC alone after 3-14 days when bleeding risk acceptable 1
   • Post-stenting (within 1-3 months): Continue P2Y12 inhibitor + OAC, stop aspirin 1

Timing Considerations for Anticoagulation Initiation

• Small infarcts without hemorrhage: Can initiate earlier (2-4 days) 1, 2, 4
• Large infarcts or hemorrhagic transformation: Delay beyond 2 weeks 1, 2, 4
• TIA without infarction: Immediate initiation is safe 1
• Direct oral anticoagulant initiation within 2 days carries 5% hemorrhagic transformation risk 4

Bottom Line

Simply having "old CVA" in the medical history does NOT justify heparin infusion. The decision to anticoagulate depends entirely on the underlying stroke mechanism and presence of ongoing indications like atrial fibrillation, not the stroke history itself. 1 For most patients with prior noncardioembolic stroke, antiplatelet therapy is superior to anticoagulation for preventing recurrent events while minimizing bleeding risk. 1