Do we still give aspirin for suspected stroke prior to ruling out whether the cerebrovascular accident (CVA) is ischemic or hemorrhagic?

Aspirin Administration in Suspected Stroke

Aspirin should not be given for suspected stroke until brain imaging has ruled out intracranial hemorrhage. 1

Rationale for Withholding Aspirin Until Imaging

• Aspirin administration carries a risk of worsening outcomes in hemorrhagic stroke by potentially increasing bleeding 1
• Brain imaging (typically CT scan) is essential to distinguish between ischemic and hemorrhagic stroke before initiating any antithrombotic therapy 1
• Parenteral anticoagulants and antiplatelet agents should not be prescribed until a brain imaging study has excluded the possibility of primary intracranial hemorrhage 1

Aspirin Administration Protocol After Ruling Out Hemorrhage

• Once hemorrhagic stroke is excluded by neuroimaging, aspirin should be given within 24-48 hours of stroke onset in most patients with ischemic stroke 1
• The recommended initial loading dose is 160-325 mg of aspirin 1
• For patients who cannot take oral medication due to impaired swallowing:
  • Rectal aspirin 325 mg daily or
  • Aspirin 81 mg daily via enteral tube 1, 2

Evidence Supporting Aspirin in Ischemic Stroke

• Early aspirin administration (within 48 hours) in confirmed ischemic stroke reduces the risk of recurrent ischemic events and mortality 1
• The International Stroke Trial and Chinese Acute Stroke Trial demonstrated a significant reduction in recurrent events with aspirin within the first 2-4 weeks 1, 3
• Combined analysis showed aspirin was effective in reducing recurrent ischemic stroke, death, or dependency 1, 3

Risks and Precautions

• Early administration of aspirin is associated with a small but significant increase in the risk of hemorrhagic transformation of infarction 1, 4
• The absolute risk increase for hemorrhagic stroke with aspirin is approximately 12 events per 10,000 persons 4
• However, this risk is outweighed by the benefits of preventing recurrent ischemic events in confirmed ischemic stroke 3, 4
• Aspirin should not be administered as adjunctive therapy within 24 hours of thrombolytic agents (rtPA) 1

Clinical Algorithm for Suspected Stroke

1. Suspect stroke based on clinical presentation
2. Obtain urgent brain imaging (CT or MRI)
3. If hemorrhagic stroke: DO NOT give aspirin 1
4. If ischemic stroke confirmed:
   • Give aspirin 160-325 mg loading dose 1, 2
   • Exception: Do not give aspirin within 24 hours of thrombolytic therapy 1
5. Continue aspirin 81-325 mg daily after the initial loading dose 1

Common Pitfalls to Avoid

• Administering aspirin before obtaining brain imaging 1
• Using aspirin as a substitute for other acute interventions, especially intravenous rtPA, for eligible patients 1
• Using enteric-coated aspirin for the loading dose as it has a slower onset of action 2, 5
• Delaying aspirin administration beyond 48 hours after symptom onset in confirmed ischemic stroke 1