Aspirin Dosing for Carotid Artery Disease
For patients with carotid artery disease, aspirin 81-325 mg daily is recommended, with the specific dose depending on whether the patient is undergoing revascularization or receiving medical management alone. 1
Dosing Based on Clinical Scenario
For Carotid Endarterectomy (CEA)
Aspirin 81-325 mg daily should be initiated before CEA and continued indefinitely postoperatively (Class I recommendation, Level of Evidence A). 1
After the first month post-CEA, you have three equally acceptable options for long-term prophylaxis: aspirin 75-325 mg daily alone, clopidogrel 75 mg daily alone, or aspirin plus extended-release dipyridamole (25/200 mg twice daily) (Class I recommendation, Level of Evidence B). 1
Low-dose aspirin (81-325 mg daily) is superior to high-dose aspirin (≥650 mg daily) for preventing perioperative stroke, MI, and death in patients undergoing CEA. 2, 3
For Carotid Artery Stenting (CAS)
Dual antiplatelet therapy with aspirin 81-325 mg daily PLUS clopidogrel 75 mg daily is required before and for a minimum of 30 days after CAS (Class I recommendation, Level of Evidence C). 1
For clopidogrel-intolerant patients, substitute ticlopidine 250 mg twice daily. 1
After the initial 30-day period, transition to single antiplatelet therapy indefinitely. 4
For Medical Management Without Revascularization
Aspirin 75-325 mg daily is recommended for patients with carotid atherosclerosis managed medically to prevent MI and other ischemic cardiovascular events. 1
The optimal dose within this range is 81-100 mg daily, as lower doses provide equivalent vascular protection with superior safety profiles compared to higher doses. 4, 2, 3
Key Evidence Supporting Lower Doses
The evidence strongly favors lower aspirin doses (81-325 mg) over higher doses (≥650 mg):
The Aspirin and Carotid Endarterectomy trial demonstrated significantly lower rates of stroke, MI, and death with low-dose aspirin compared to high-dose regimens. 4
Multiple meta-analyses confirm that aspirin doses below 100 mg daily are as effective as higher doses for stroke prevention, with fewer gastrointestinal bleeding complications. 5, 6
Research specifically in carotid stenosis patients shows low to medium dose aspirin (81-325 mg daily) is superior to doses exceeding 650 mg daily at preventing recurrent vascular events. 3
Critical Clinical Pitfalls
Do not use aspirin monotherapy in the immediate peri-procedural period for CAS—this is a Class I recommendation requiring dual antiplatelet therapy for at least 30 days. 1
Do not exceed 325 mg daily—higher doses increase bleeding risk without improving efficacy and may actually worsen outcomes. 2, 3, 5
Do not initiate aspirin in patients at very high bleeding risk without carefully weighing cardiovascular benefit against hemorrhagic risk. 4
Monitoring Requirements
Annual follow-up is mandatory to assess cardiovascular risk factors, treatment compliance, and neurological symptoms. 4
Noninvasive imaging of the carotid arteries at 1 month, 6 months, and annually after revascularization is reasonable to assess patency and detect new lesions. 1
Monitor hemoglobin levels and clinical bleeding parameters in patients on antiplatelet therapy. 4