DAPT Duration After Ischemic Stroke
For patients with minor ischemic stroke or high-risk TIA, dual antiplatelet therapy (aspirin plus clopidogrel) should be administered for 21-30 days, initiated within 24 hours of symptom onset, followed by lifelong single antiplatelet therapy. 1, 2
Treatment Algorithm Based on Stroke Severity
Minor Stroke or High-Risk TIA
- Initiate DAPT as soon as possible after brain imaging excludes hemorrhage, ideally within 12 hours and no later than 24 hours of symptom onset 2
- Loading dose: Clopidogrel 300-600 mg plus Aspirin 160-325 mg 2
- Maintenance regimen: Aspirin 81 mg daily plus Clopidogrel 75 mg daily for exactly 21-30 days 1, 2, 3
- After 21-30 days: Transition to lifelong single antiplatelet therapy (aspirin or clopidogrel) 1, 2
Moderate to Severe Stroke
- Single antiplatelet therapy only is recommended 2
- Aspirin 160 mg loading dose, then 81-325 mg daily 2
- DAPT is NOT recommended in this population 2
Critical Evidence Supporting the 21-30 Day Duration
The 21-30 day duration represents the optimal risk-benefit window based on rigorous analysis. For every 1,000 patients treated with DAPT for 90 days, 15 ischemic strokes are prevented but 5 major hemorrhages are caused, demonstrating that extending beyond 30 days increases bleeding risk without proportional benefit 2. Short-term DAPT (≤30 days) reduces recurrent ischemic stroke by 41% and major vascular events by 30% without increasing intracranial hemorrhage risk 4. In contrast, prolonged DAPT (≥1 year) shows no additional reduction in ischemic stroke risk when continued for 2-3 years, while bleeding risk accumulates over time 1, 2.
Recent meta-analysis confirms that short-term DAPT (≤30 days) demonstrates greater reduction in recurrent ischemic events (RR 0.65) compared to long-term DAPT (>30 days; RR 0.72) 5. The European Stroke Organisation provides a strong recommendation based on high-quality evidence for 21 days of aspirin plus clopidogrel 3.
Absolute Contraindications to DAPT
Do NOT use DAPT in patients who:
- Received thrombolysis (alteplase) 2
- Have cardioembolic stroke mechanism 2, 3
- Have high bleeding risk (prior bleeding on DAPT, coagulopathy, oral anticoagulant use) 2
- Have moderate to severe stroke 2
Special Populations and Exceptions
Large-Artery Intracranial Atherosclerosis
- Extended DAPT for 90 days may be considered in patients with symptomatic large vessel intracranial atherosclerotic disease 6
- Recent evidence suggests continuation beyond 3 months (up to 6 months) may confer net clinical benefits in this specific subgroup without increasing major bleeding risk (adjusted HR 0.78 at both 3 and 6 months) 7
- This represents an exception to the standard 21-30 day recommendation and applies only to documented large-artery atherosclerosis 7
Carotid Revascularization
- For patients undergoing carotid endarterectomy, consider aspirin monotherapy instead of DAPT to reduce perioperative bleeding risk 2
- Post-procedure, reduce to single antiplatelet agent from day 1, typically maintained for 1-3 months 2
Bleeding Risk Mitigation
- Consider proton pump inhibitor in patients at higher risk of gastrointestinal bleeding during DAPT 2
Common Pitfalls to Avoid
Do not continue DAPT indefinitely beyond 30 days unless the patient has documented large-artery intracranial atherosclerosis requiring extended therapy 1, 2. Long-term DAPT (≥1 year) after stroke shows no benefit over single antiplatelet therapy for recurrent stroke prevention and significantly increases risk of intracranial hemorrhage and major bleeding 1. The exact duration at which hemorrhage risk begins to outweigh benefit is as early as 21-90 days, with older patients and those with more severe stroke at higher risk 1.
Verify there are no other indications for prolonged DAPT (such as recent drug-eluting cardiac stent placement) that might justify continuation beyond the stroke-specific recommendation, but ensure these indications are clearly documented and time-limited 1.