What are the high-risk features that indicate the use of Dual Antiplatelet Therapy (DAPT) in patients with intracranial dissection?

High-Risk Features for DAPT in Intracranial Dissection

Dual antiplatelet therapy (DAPT) is recommended for patients with intracranial arterial dissection who present with high-risk features, particularly within the first 21-30 days after the event. 1, 2

Key High-Risk Features Indicating DAPT Use

• Recent symptom onset (within 24-72 hours) - Patients presenting within this timeframe have shown greatest benefit from DAPT in clinical trials 1
• Minor ischemic stroke - Defined as non-disabling stroke with minimal neurological deficits 1
• High-risk TIA - Particularly those with transient, fluctuating or persistent unilateral weakness, language/speech disturbance, or other focal neurological symptoms 1
• Symptomatic intracranial arterial stenosis of ≥50% - Particularly in major intracranial arteries 2
• Presence of thromboembolic complications - Including microemboli detected on imaging 3
• Recurrent ischemic symptoms despite single antiplatelet therapy 1

Evidence Supporting DAPT in Intracranial Dissection

• DAPT with aspirin plus clopidogrel has demonstrated a 32% relative risk reduction in recurrent ischemic stroke compared to single antiplatelet therapy in patients with minor stroke or high-risk TIA (RR 0.68,95% CI 0.55-0.83) 1
• DAPT initiated within 24 hours of symptom onset, and ideally within 12 hours, provides optimal benefit 1
• For patients with intracranial arterial stenosis specifically, DAPT using cilostazol plus either clopidogrel or aspirin showed superior outcomes compared to single antiplatelet therapy (HR 0.47,95% CI 0.23-0.95) 2
• DAPT with ticagrelor plus aspirin has shown significantly lower thromboembolic events compared to clopidogrel plus aspirin in patients with intracranial aneurysms undergoing endovascular intervention 3

Duration of DAPT

• Short-term DAPT (21-30 days) is recommended for most patients with intracranial dissection presenting with high-risk features 1
• Long-term DAPT (>90 days) has not shown significant benefit in reducing recurrent ischemic stroke (RR 0.89,95% CI 0.79-1.02) but increases bleeding risk 1
• After the initial DAPT period, patients should transition to monotherapy indefinitely 1

Loading Dose Recommendations

• Initial loading dose: Aspirin 160-325 mg AND clopidogrel 300-600 mg should be administered after excluding intracranial hemorrhage 4
• Maintenance dose: Aspirin 81 mg daily plus clopidogrel 75 mg daily for 21-30 days 1, 4
• Alternative regimen: Loading dose of aspirin 300-325 mg AND ticagrelor 180 mg, followed by aspirin 75-100 mg daily and ticagrelor 90 mg twice daily for 30 days 4

Bleeding Risk Considerations

• DAPT increases risk of major bleeding compared to single antiplatelet therapy (RR 1.88,95% CI 0.93-3.83) 1
• Higher bleeding risk is observed with prolonged DAPT (>90 days) with pooled RR of 2.42 (95% CI 1.37-4.30) 1
• Consider GI protection for patients at higher risk of bleeding while on DAPT 1
• In patients with very high bleeding risk (e.g., requiring oral anticoagulation or facing major intracranial surgery), the risk-benefit ratio may favor shorter DAPT duration 1

Special Considerations

• For patients requiring urgent surgical intervention, coordination with the surgeon is essential to determine appropriate timing and selection of antiplatelet agents 1
• In patients who cannot take oral medication due to dysphagia, aspirin 80 mg daily and clopidogrel 75 mg daily may be given by enteral tube, or aspirin 325 mg daily by rectal suppository 1, 4
• For patients with intracranial dissection who have received thrombolysis, initiation of antiplatelet therapy should be delayed until after the 24-hour post-thrombolysis scan has excluded intracranial hemorrhage 1

Monitoring and Follow-up

• Regular clinical assessment for recurrent ischemic symptoms and bleeding complications 1
• Consider follow-up vascular imaging to assess for resolution or progression of dissection 2, 5
• Monitor for medication adherence and side effects that might affect compliance 6