What is the recommended treatment for a patient with carotid stenosis, specifically regarding aspirin (acetylsalicylic acid) therapy?

Aspirin Therapy for Carotid Stenosis

All patients with carotid stenosis should receive aspirin 75-100 mg daily (or up to 325 mg) as foundational antiplatelet therapy, with specific regimens varying based on whether the stenosis is symptomatic or asymptomatic and whether revascularization is planned. 1

Asymptomatic Carotid Stenosis

For patients with asymptomatic carotid stenosis ≥50%, aspirin 75-100 mg daily should be initiated if bleeding risk is low. 1, 2 This recommendation applies to patients who have had no TIA, stroke, or amaurosis fugax in the ipsilateral territory within the past 6 months. 2

• Low-dose aspirin (75-100 mg) is preferred over higher doses, as the Aspirin and Carotid Endarterectomy trial demonstrated lower combined rates of stroke, MI, and death with 81-325 mg compared to high-dose groups (650-1,300 mg). 1
• Clopidogrel 75 mg daily is an acceptable alternative to aspirin for patients who cannot tolerate aspirin. 1, 2
• The benefit is modest but meaningful when taken over 10 years, with slight reduction in total mortality balanced against increased bleeding risk in moderate to high cardiovascular risk patients. 1

Symptomatic Carotid Stenosis (Not Undergoing Revascularization)

For symptomatic carotid stenosis ≥50%, dual antiplatelet therapy (DAPT) with aspirin 75-100 mg plus clopidogrel 75 mg daily is recommended for at least 21 days, followed by single antiplatelet therapy (either clopidogrel 75 mg daily or aspirin-extended-release dipyridamole 25/200 mg twice daily preferred over aspirin alone). 1, 3

• DAPT is particularly critical in the early phase after minor stroke or TIA, as it significantly reduces asymptomatic embolization and recurrent stroke risk. 3, 4
• The CARESS trial demonstrated that combination therapy reduced microembolic signals by 61.4% compared to aspirin monotherapy, with fewer recurrent strokes (0 vs 4) and TIAs (4 vs 7) in the dual-therapy group. 4
• After the initial 21-day period, transition to single antiplatelet therapy with either clopidogrel 75 mg daily or aspirin-dipyridamole (preferred over aspirin alone). 1, 3

Perioperative Management for Carotid Endarterectomy (CEA)

Aspirin 81-325 mg daily should be started before CEA and continued indefinitely postoperatively. 1

• Aspirin was used in all major CEA trials and is considered essential perioperative therapy. 1
• Low to medium dose aspirin (81-325 mg) is superior to higher doses (>650 mg) at preventing recurrent vascular events perioperatively. 1, 5
• After the first month post-CEA, continue with aspirin 75-325 mg daily, clopidogrel 75 mg daily, or aspirin-extended-release dipyridamole for long-term prophylaxis. 1
• Some surgeons prefer DAPT perioperatively, which can then be reduced to single antiplatelet therapy maintained for 1-3 months. 3

Perioperative Management for Carotid Artery Stenting (CAS)

Before and for a minimum of 30 days after CAS, dual antiplatelet therapy with aspirin 81-325 mg daily plus clopidogrel 75 mg daily is mandatory. 1

• For patients intolerant of clopidogrel, ticlopidine 250 mg twice daily may be substituted. 1
• After 1 month post-stenting, transition to long-term single antiplatelet therapy (aspirin or clopidogrel). 3
• Premature discontinuation of DAPT after carotid stenting significantly increases the risk of stent thrombosis. 3

Stenosis <50%

For carotid stenosis <50%, revascularization is not indicated (Class III recommendation), but antiplatelet therapy with aspirin should still be initiated as part of optimal medical therapy. 1, 6

• Even though revascularization provides no benefit, these patients require aggressive medical management including antiplatelet therapy to prevent stroke. 6
• The same aspirin dosing applies: 75-100 mg daily for asymptomatic patients, with consideration of DAPT for symptomatic patients. 6

Critical Pitfalls to Avoid

• Do not use high-dose aspirin (>325 mg): Higher doses increase bleeding risk without additional benefit and may actually worsen outcomes. 1
• Do not stop DAPT prematurely after CAS: This dramatically increases stent thrombosis risk; maintain for minimum 30 days. 3
• Do not continue DAPT indefinitely without reassessment: After the recommended duration (21 days for symptomatic stenosis, 30 days for CAS), transition to single antiplatelet therapy to reduce bleeding risk. 3
• Do not forget bleeding risk assessment: Always evaluate bleeding risk before initiating antiplatelet therapy, especially DAPT. 3
• Do not use anticoagulation instead of antiplatelet therapy: Anticoagulation with heparins or vitamin K antagonists is not recommended except in patients at risk for cardioembolic events. 7

Long-term Monitoring

• Annual follow-up is essential to assess cardiovascular risk factors, treatment compliance, and neurological symptoms. 3, 2
• Duplex ultrasound surveillance should be performed periodically to assess for stenosis progression. 2
• Reassess antiplatelet therapy adherence at each visit, as non-compliance significantly increases stroke risk. 2