What is the recommended duration of Dual Antiplatelet Therapy (DAPT) in patients with ischemic stroke?

Duration of Dual Antiplatelet Therapy (DAPT) in Ischemic Stroke

For patients with ischemic stroke or high-risk TIA, dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel should be administered for 21-30 days after the event, followed by long-term single antiplatelet therapy. 1

Patient Selection for DAPT

• DAPT is recommended for:
  • Minor ischemic stroke (NIHSS ≤3) or high-risk TIA (ABCD2 score ≥4) 1
  • Mild-moderate ischemic stroke (NIHSS ≤5) may also benefit 1
  • Non-hemorrhagic stroke (confirmed by neuroimaging) 1

Optimal Duration of DAPT

Short-term DAPT (21-30 days)

• Short-duration DAPT (≤1 month) started during the early acute ischemic phase provides:
  • Greater reduction in recurrent strokes compared to monotherapy 2
  • Less bleeding risk than longer DAPT regimens 2
  • 26% reduction in recurrent stroke risk compared to aspirin alone 3

Evidence Against Longer DAPT Duration

• DAPT beyond 21-30 days shows:
  • Significantly increased risk of moderate or severe bleeding 4
  • Similar rates of stroke prevention as monotherapy 2
  • Risk of major hemorrhage increases with longer durations 1

Recommended DAPT Regimens

Aspirin + Clopidogrel (Preferred)

• Loading dose: Aspirin 160-325mg + Clopidogrel 300-600mg
• Maintenance dose: Aspirin 81mg daily + Clopidogrel 75mg daily
• Duration: 21 days 1

Aspirin + Ticagrelor (Alternative)

• Loading dose: Aspirin 300-325mg + Ticagrelor 180mg
• Maintenance dose: Aspirin 75-100mg daily + Ticagrelor 90mg twice daily
• Duration: 30 days 1

Efficacy and Safety Considerations

Benefits

• DAPT reduces risk of recurrent stroke by 24-26% compared to aspirin alone 3, 4
• Reduces risk of ischemic stroke by 28% 3
• Reduces major adverse cardiovascular events by 24% 3

Risks

• Increases risk of moderate or severe bleeding (RR: 1.88-2.17) 3, 4
• Higher risk of intracranial bleeding (RR 1.55) 2
• Number needed to harm for major bleeding: 113 2

Transition to Long-term Therapy

After completing the 21-30 day DAPT course, patients should transition to single antiplatelet therapy with one of the following:

• Aspirin 81-325mg daily
• Clopidogrel 75mg daily
• Aspirin 25mg + extended-release dipyridamole 200mg twice daily 1

Important Clinical Considerations

• Timing is critical: Initiate DAPT as early as possible (ideally within 12-24 hours) after symptom onset 1
• Recent evidence: The INSPIRES trial (2023) showed benefit of DAPT initiated within 72 hours, but still with increased bleeding risk 5
• Monitor for bleeding: Watch for both minor (bruising) and major (intracranial) bleeding complications 1
• Patient education: Inform patients about the short-term nature of DAPT and importance of transitioning to long-term single antiplatelet therapy 1

The 21-30 day duration represents the optimal balance between stroke prevention and bleeding risk, with longer durations showing diminishing returns in terms of efficacy while significantly increasing bleeding complications.