Duration of Antiplatelet Therapy in Intracranial Atherosclerotic Disease
For patients with symptomatic intracranial atherosclerotic disease (ICAD), initiate dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel for 90 days, followed by long-term single antiplatelet therapy indefinitely. 1, 2
Acute Phase: Initial 90 Days
Loading and Maintenance Dosing
- Administer loading doses of aspirin 160-325 mg plus clopidogrel 300-600 mg within 12-24 hours after excluding intracranial hemorrhage on neuroimaging 1, 2
- Continue maintenance therapy with aspirin 81-325 mg daily plus clopidogrel 75 mg daily for the full 90-day period 1, 2
- This 90-day DAPT regimen is specifically recommended for patients with severe stenosis (70-99%) who have experienced stroke or TIA within the past 30 days 2
Alternative Short-Duration DAPT (21-30 Days)
- For minor ischemic stroke (NIHSS ≤3) or high-risk TIA (ABCD2 ≥4), DAPT for 21 days is acceptable based on the CHANCE trial protocol, followed by single antiplatelet therapy 3, 1
- Aspirin plus ticagrelor for 30 days may be considered as an alternative regimen for mild-moderate stroke (NIHSS ≤5), though this is less established for ICAD specifically 3
Long-Term Maintenance: After 90 Days
Transition to Single Antiplatelet Therapy
- After completing 90 days of DAPT, transition to single antiplatelet therapy indefinitely with either aspirin 81-325 mg daily or clopidogrel 75 mg daily 3, 1
- Long-term antiplatelet therapy is indicated for all patients with non-cardioembolic ischemic stroke or TIA who do not require anticoagulation 3
Special Consideration: Intracranial Stenting
If Stent Placement Occurs
- For bare-metal intracranial stents: Continue DAPT for a minimum of 4 weeks, then transition to aspirin monotherapy indefinitely 1, 4
- For drug-eluting intracranial stents: Continue DAPT for 6-12 months, then transition to aspirin monotherapy indefinitely 1, 4
- Critical caveat: Intracranial stenting is NOT first-line therapy for symptomatic ICAD; aggressive medical management with DAPT is superior based on the SAMMPRIS trial 1, 2
Essential Adjunctive Medical Management
Risk Factor Control During DAPT
- Maintain systolic blood pressure <140 mmHg throughout treatment 1, 2
- Initiate high-dose statin therapy to reduce recurrent stroke risk 1, 2
- Implement at least moderate physical activity and aggressive diabetes management 1, 2
- Provide gastrointestinal prophylaxis for the entire duration of DAPT to minimize bleeding complications 5
Evidence Strength and Nuances
Supporting Data for 90-Day Duration
- A pilot study of 25 patients with high-grade symptomatic ICAD treated with 12 months of DAPT showed 0% rate of stroke/MI/vascular death at 1 year compared to 16% in the SAMMPRIS medical arm (which used only 90 days of DAPT), with similar bleeding rates 5
- However, the World Stroke Organization guidelines and American Heart Association recommendations support 90 days as the standard duration, balancing efficacy against bleeding risk 1, 2
- Extended DAPT beyond 90 days may be reasonable in highly selected patients who tolerate therapy without bleeding complications and are not at high bleeding risk, though this remains investigational 6, 5
Critical Pitfalls to Avoid
Timing and Duration Errors
- Never delay DAPT initiation beyond 72 hours from symptom onset, as benefit is most pronounced when started within 12-24 hours 1, 7
- Do not discontinue DAPT prematurely before completing the recommended 90-day course, as recurrent stroke risk remains elevated in the early period 1, 6
- Avoid prolonged DAPT beyond 90 days in routine practice without careful consideration of bleeding risk, as hemorrhagic complications increase with extended duration 6
Medication Selection Errors
- Do not use anticoagulation (warfarin or DOACs) for ICAD unless there is a separate indication such as atrial fibrillation, as anticoagulation is not more effective than antiplatelet therapy and carries higher bleeding risk 8, 9
- Do not use ticagrelor for intracranial stenting due to increased intracranial hemorrhage risk without proven benefit in this specific population 4