Antiplatelet Regimen for Extracranial Stent Placement
For extracranial carotid or vertebral artery stenting, use dual antiplatelet therapy with aspirin 75-325 mg daily plus clopidogrel 75 mg daily for at least 30 days post-procedure, followed by single antiplatelet therapy indefinitely. 1
Initial Periprocedural Period (First 30 Days)
Administer dual antiplatelet therapy with aspirin 75-325 mg daily and clopidogrel 75 mg daily for the first month after extracranial stent placement. 1
This recommendation mirrors the approach for bare-metal coronary stents, which is the most applicable evidence for extracranial cerebrovascular stenting given the lack of specific high-quality trials for this indication. 1
The aspirin dose can range from 75-325 mg during this initial period, though many practitioners use 325 mg acutely and then reduce to 81-100 mg for maintenance. 1
Months 2-12 Post-Stenting
Continue dual antiplatelet therapy with low-dose aspirin 75-100 mg daily and clopidogrel 75 mg daily for up to 12 months. 1
This extended duration is suggested (Grade 2C evidence) rather than strongly recommended, reflecting weaker evidence for benefit beyond the first month. 1
The rationale is to prevent late stent thrombosis during the endothelialization period, which may take several months to complete. 1
After 12 Months
Transition to single antiplatelet therapy after 12 months, as continuing dual therapy beyond this point provides no additional benefit and may increase bleeding risk. 1
Single antiplatelet therapy should continue indefinitely for secondary stroke prevention in patients with extracranial atherosclerotic disease. 1
Acceptable single antiplatelet options include aspirin 75-325 mg daily, clopidogrel 75 mg daily, or aspirin plus extended-release dipyridamole (25/200 mg twice daily). 1
Critical Caveats and Pitfalls
Never discontinue both antiplatelet agents simultaneously in the first 12 months post-stenting due to catastrophic risk of acute stent thrombosis. 2 The thrombotic risk is highest in the first 6 weeks after stent placement. 2
If bleeding complications occur, consider reducing aspirin dose to 75-81 mg while maintaining clopidogrel, rather than stopping both agents. 1
Be aware that the MATCH trial demonstrated a 1.3% absolute increase in life-threatening bleeding with dual antiplatelet therapy in high-risk stroke patients, so vigilance for hemorrhagic complications is essential. 1
Drug-eluting stents, if used in extracranial vessels, would theoretically require longer dual antiplatelet therapy (3-6 months minimum), though these are rarely used in cerebrovascular applications. 1
Alternative Regimens for Special Circumstances
If the patient has an allergy or intolerance to either aspirin or clopidogrel, cilostazol 100 mg twice daily can substitute for the problematic agent as part of dual antiplatelet therapy. 1
Do not add cilostazol as a third agent to aspirin plus clopidogrel, as this increases side effects (particularly dizziness) without proven benefit. 1, 2
Monitor for drug interactions, particularly with proton pump inhibitors that may reduce clopidogrel effectiveness. 2
Evidence Quality Considerations
The recommendations for extracranial stenting are extrapolated primarily from coronary stenting data, as specific high-quality trials for cerebrovascular stenting are limited. 1 The American College of Chest Physicians guidelines provide Grade 1A evidence for the first month of dual therapy with bare-metal stents, but only Grade 2C evidence for continuation beyond that period. 1 The 2011 multisociety guidelines on extracranial carotid and vertebral disease recommend antiplatelet therapy consistent with these principles but acknowledge the evidence base is less robust than for coronary interventions. 1