Should a patient with vertebral artery dissection due to hypertensive emergency start Acetylsalicylic Acid (ASA) before undergoing a stent placement procedure?

ASA Should Be Started Immediately in Vertebral Artery Dissection, Even Before Stent Placement

For patients with vertebral artery dissection due to hypertensive emergency who require stent placement, aspirin (ASA) should be initiated immediately upon diagnosis and continued through the stenting procedure. This recommendation is based on established guidelines for both acute cerebrovascular events and endovascular stent procedures.

Rationale for Immediate ASA Initiation

Acute Cerebrovascular Protection

• ASA should be started immediately when vertebral artery dissection is diagnosed, as it provides prompt antiplatelet action to prevent thromboembolic complications 1
• The initial loading dose should be 162-325 mg (non-enteric coated for faster buccal absorption), followed by maintenance dosing 1
• Vertebral artery dissections carry high stroke risk through distal embolism, making immediate antiplatelet therapy critical 2, 3

Pre-Stenting Requirements

• Dual antiplatelet therapy with aspirin (81-325 mg daily) plus clopidogrel (75 mg daily) is mandatory for a minimum of 30 days after carotid and vertebral artery stenting 1
• This dual therapy should ideally be initiated before the stenting procedure when possible 1
• In endovascular stenting for vertebral artery disease, all patients are maintained on daily antiplatelet therapy following the procedure 4

Dosing Strategy

Loading Phase

• Administer 162-325 mg ASA immediately upon diagnosis (non-enteric coated formulation preferred) 1
• Add clopidogrel 300-600 mg loading dose if stenting is planned imminently 1

Maintenance After Stenting

• Continue ASA 81-325 mg daily for at least 30 days post-stent 1
• Maintain dual antiplatelet therapy (ASA + clopidogrel 75 mg daily) for minimum 30 days 1
• After 30 days, continue ASA indefinitely for secondary stroke prevention 1

Critical Timing Considerations

The concern about "waiting for a procedure" does not apply here because:

1. ASA is required both for the acute dissection AND for the stenting procedure - there is no conflict 1, 4
2. Unlike elective surgeries where ASA may increase bleeding risk, endovascular stenting specifically requires antiplatelet therapy 1, 4
3. The 5-7 day ASA discontinuation window only applies to high-bleeding-risk surgeries (intracranial, spinal procedures), not to endovascular interventions 5, 6

Common Pitfalls to Avoid

• Do not delay ASA initiation while awaiting stent placement - the dissection itself requires immediate antiplatelet therapy to prevent embolic stroke 2, 3
• Do not confuse vertebral artery stenting with high-bleeding-risk surgeries - stenting requires antiplatelet therapy, not discontinuation 1, 4
• Do not use enteric-coated ASA for initial loading - non-enteric formulations provide faster therapeutic effect 1
• Do not stop ASA after stenting - continue indefinitely for secondary prevention unless contraindications develop 1

Bleeding Risk Management

• The major bleeding rate with ASA 75-162 mg daily is approximately 2.0-2.3%, which is acceptable given the high thrombotic risk of vertebral dissection 1
• Maintenance doses of 75-162 mg are preferred long-term to minimize bleeding while maintaining efficacy 1
• Blood pressure control is essential both before and after stenting to reduce hemorrhagic complications 1