What are the guidelines for anticoagulation (prevention of blood clot formation) and anti-platelet (inhibition of platelet aggregation) therapy after an ischemic stroke?

Anticoagulation and Antiplatelet Guidelines After Ischemic Stroke

For patients with ischemic stroke, early aspirin therapy (160-325 mg within 48 hours) is strongly recommended as first-line antithrombotic therapy, while specific anticoagulation or antiplatelet regimens for long-term secondary prevention should be tailored based on stroke etiology. 1

Acute Management (First 48 Hours)

Initial Antithrombotic Therapy

• Early aspirin therapy (160-325 mg within 48 hours) is strongly recommended for all patients with acute ischemic stroke or TIA (Grade 1A) 1, 2
• Aspirin is preferred over therapeutic parenteral anticoagulation in the acute setting (Grade 1A) 1
• Urgent anticoagulation with the goal of preventing early recurrent stroke is NOT recommended (Class III, Level of Evidence A) 1

DVT Prophylaxis in Immobile Patients

• For patients with restricted mobility:
  • Prophylactic-dose subcutaneous heparin (LMWH or UFH) or intermittent pneumatic compression devices are recommended (Grade 2B) 1
  • LMWH is preferred over UFH for DVT prophylaxis (Grade 2B) 1, 2
  • Avoid elastic compression stockings (Grade 2B) 1

Long-Term Secondary Prevention

For Non-Cardioembolic Stroke/TIA

• Recommended antiplatelet options (Grade 1A) 1:

  1. Aspirin (75-100 mg once daily)
  2. Clopidogrel (75 mg once daily)
  3. Aspirin/extended-release dipyridamole (25 mg/200 mg twice daily)
  4. Cilostazol (100 mg twice daily)

• Preferred antiplatelet regimens:

  • Clopidogrel or aspirin/extended-release dipyridamole are suggested over aspirin alone (Grade 2B) 1
  • Recent evidence supports short-term dual antiplatelet therapy (aspirin plus clopidogrel) for 21-30 days in patients with minor stroke or high-risk TIA, followed by single antiplatelet therapy 3

For Cardioembolic Stroke/TIA (with Atrial Fibrillation)

• Oral anticoagulation is strongly recommended over:

  • No antithrombotic therapy (Grade 1A)
  • Aspirin alone (Grade 1B)
  • Combination therapy with aspirin and clopidogrel (Grade 1B) 1

• Anticoagulation options:

  • Dabigatran 150 mg twice daily is suggested over adjusted-dose vitamin K antagonists (VKA) (Grade 2B) 1
  • Direct oral anticoagulants (DOACs) may be preferred over warfarin due to decreased bleeding risks, no need for INR monitoring, and fewer drug interactions 3

• Timing of anticoagulation initiation:

  • Generally within 1-2 weeks after stroke onset 1
  • Earlier anticoagulation (within days) may be considered for patients with small infarcts and low bleeding risk
  • Delayed anticoagulation should be considered for patients with large infarcts or hemorrhagic transformation 1

For Patients Unable to Take Oral Anticoagulants

• For AF patients who cannot take oral anticoagulants (for reasons other than bleeding risk), combination therapy with aspirin and clopidogrel is recommended over aspirin alone (Grade 1B) 1

Special Considerations

Primary Intracerebral Hemorrhage

• For patients with history of symptomatic primary ICH, long-term antithrombotic therapy for stroke prevention is generally not recommended (Grade 2C) 1
• For patients with restricted mobility after ICH:
  • Prophylactic-dose subcutaneous heparin started between days 2-4 or intermittent pneumatic compression devices are suggested (Grade 2C) 1
  • LMWH is preferred over UFH (Grade 2B) 1

Common Pitfalls to Avoid

1. Initiating anticoagulation too early: Starting anticoagulation within 24 hours of IV r-tPA is not recommended due to increased bleeding risk 1
2. Prolonged dual antiplatelet therapy: Extended DAPT beyond recommended durations increases bleeding risk without additional benefit 3
3. Inappropriate use of anticoagulation: Urgent anticoagulation for non-cardioembolic stroke is not beneficial and increases bleeding risk 1
4. Overlooking renal function: Dabigatran is contraindicated in severe renal impairment (CrCl ≤30 mL/min) 1

By following these evidence-based guidelines, clinicians can optimize antithrombotic therapy after ischemic stroke to reduce morbidity and mortality while minimizing bleeding complications.