What is the recommended anticoagulation therapy for a patient with a history of stroke?

Recommended Anticoagulation Therapy for Patients with History of Stroke

For patients with a history of stroke and atrial fibrillation, direct oral anticoagulants (DOACs) such as apixaban, dabigatran, edoxaban, or rivaroxaban are recommended over warfarin to reduce the risk of recurrent stroke. 1

Anticoagulation Based on Stroke Etiology

For Patients with Atrial Fibrillation

1. Non-valvular Atrial Fibrillation:

   • First-line therapy: DOACs (apixaban, dabigatran, edoxaban, or rivaroxaban) 1
   • Second-line therapy: Warfarin (target INR 2.0-3.0) if DOACs cannot be used 1
   • DOACs are preferred over vitamin K antagonists due to:
     • Lower risk of intracranial hemorrhage
     • No need for regular INR monitoring
     • Fewer drug-drug interactions 1

2. Valvular Atrial Fibrillation (mechanical valve replacement or moderate/severe mitral stenosis):

   • Warfarin is recommended (target INR 2.5-3.5) 1
   • DOACs should NOT be used in patients with mechanical heart valves or moderate to severe mitral stenosis 1

3. Timing of Anticoagulation Initiation After Stroke:

   • For TIA: Reasonable to initiate anticoagulation immediately 1
   • For stroke with low risk of hemorrhagic conversion: May initiate anticoagulation 2-14 days after stroke 1
   • For stroke with high risk of hemorrhagic conversion: Delay initiation beyond 14 days 1

For Patients with Non-Cardioembolic Stroke

1. Long-term antiplatelet therapy options:

   • Clopidogrel (75 mg daily) 1, 2
   • Aspirin (75-100 mg daily) plus extended-release dipyridamole (200 mg twice daily) 1, 2
   • Aspirin alone (75-100 mg daily) 1
   • Cilostazol (100 mg twice daily) 1

2. Preferred antiplatelet regimens:

   • Clopidogrel or aspirin/extended-release dipyridamole are preferred over aspirin alone 1
   • For patients who had a stroke while on aspirin, changing to clopidogrel or aspirin plus extended-release dipyridamole is recommended 2

For Patients with Mechanical Heart Valves

1. Mitral Valve Replacement:

   • Warfarin with target INR of 3.0 (range 2.5-3.5) 3
   • For patients with previous stroke before valve replacement, add aspirin 75-100 mg daily to warfarin 1

2. Aortic Valve Replacement:

   • For St. Jude Medical bileaflet valve: Warfarin with target INR of 2.5 (range 2.0-3.0) 3
   • For other mechanical aortic valves: Warfarin with target INR of 3.0 (range 2.5-3.5) 3

Special Considerations

For Patients with Stroke Despite Being on Anticoagulation

Recent evidence suggests that for patients who experience an ischemic stroke while on a DOAC:

• Continuing the same DOAC is more effective than switching to warfarin or changing to a different DOAC 4
• Switching to warfarin is associated with higher risks of recurrent stroke, intracranial hemorrhage, and mortality compared to continuing the same DOAC 4

For Patients with Subclinical Atrial Fibrillation

In patients with subclinical atrial fibrillation and a history of stroke or TIA:

• Apixaban provides a 7% absolute risk reduction in stroke or systemic embolism over 3.5 years compared to aspirin, with only a 3% increase in major bleeding risk 5

For Patients with Renal Impairment

• For patients with end-stage renal disease or on dialysis, warfarin or dose-adjusted apixaban may be reasonable 1
• Dabigatran is contraindicated in patients with severe renal impairment (creatinine clearance ≤30 mL/min) 1

Pitfalls and Caveats

1. Avoid combining anticoagulants with antiplatelets unless specifically indicated (e.g., mechanical heart valves), as this significantly increases bleeding risk 1

2. Monitor for drug interactions:

   • Cytochrome P450/P-glycoprotein modulators can affect DOAC levels and increase stroke risk 6
   • Adjust DOAC doses accordingly when used with interacting medications

3. Consider stroke mechanism when selecting therapy:

   • Diabetes mellitus and large artery atherosclerotic disease are predictors of recurrent stroke despite anticoagulation 6

4. For patients unable to take oral anticoagulants due to contraindications (other than bleeding concerns), combination therapy with aspirin and clopidogrel is recommended over aspirin alone in AF patients 1

5. Left atrial appendage closure (Watchman device) may be reasonable for patients with contraindications to lifelong anticoagulation who can tolerate at least 45 days of anticoagulation 1