What is the management approach for a patient with existing internal carotid artery (ICA) stenosis?

Management of Existing Internal Carotid Artery Stenosis

The management of existing ICA stenosis depends critically on whether the patient is symptomatic or asymptomatic, with symptomatic patients requiring immediate dual antiplatelet therapy and urgent vascular team assessment, while asymptomatic patients should receive intensive medical management with selective consideration for revascularization based on high-risk features. 1, 2

Initial Assessment and Diagnostic Workup

Imaging Strategy

• Use duplex ultrasound (DUS) as the first-line imaging modality to confirm and quantify ICA stenosis. 1, 3
• Apply the NASCET method (not ECST method) to accurately measure stenosis severity, as ECST overestimates stenosis and creates confusion between imaging modalities. 1, 2
• Obtain CTA or MRA when DUS findings are inconclusive or when detailed anatomic characterization is needed for intervention planning. 2, 3

Multidisciplinary Evaluation

• All symptomatic ICA stenosis patients must be assessed by a vascular team including a neurologist. 1, 4
• This assessment should occur urgently, as stroke risk is highest in the first few weeks following symptomatic events. 2, 5

Management Algorithm Based on Symptom Status

For Symptomatic ICA Stenosis

Immediate Medical Therapy

• Initiate dual antiplatelet therapy (DAPT) with aspirin and clopidogrel 75mg immediately for at least 21 days in all symptomatic patients. 1, 2, 4
• Start high-intensity statin therapy targeting LDL-C <1.4 mmol/L (<55 mg/dL). 1, 6
• Optimize blood pressure control to <140/90 mmHg using thiazide diuretics, ACE inhibitors, or ARBs preferentially. 6

Revascularization Decision-Making

• For 70-99% stenosis: Perform carotid endarterectomy (CEA) within 14 days if the documented 30-day procedural risk of death/stroke is <6%. 1, 4, 3
• For 50-69% stenosis: Consider CEA in selected patients with recent symptoms. 5
• For <50% stenosis: Revascularization is not recommended; continue optimal medical therapy alone. 1

Procedural Selection

• CEA remains the preferred revascularization method for symptomatic 70-99% stenosis, particularly in patients with contralateral carotid occlusion. 4
• Carotid artery stenting (CAS) may be considered in high surgical risk patients, though registry data shows higher 1-year stroke/death rates (9.7% for CAS vs 5.2% for CEA). 4

For Asymptomatic ICA Stenosis

Risk Stratification

• In asymptomatic patients without high-risk features and life expectancy <5 years, routine revascularization is not recommended. 1
• Recent evidence from CREST-2 (2025) shows that among patients with high-grade asymptomatic stenosis, stenting plus intensive medical management resulted in lower 4-year event rates (2.8%) compared to medical management alone (6.0%), while endarterectomy did not show significant benefit. 7

Medical Management

• Implement intensive medical therapy including high-intensity statins, blood pressure control, and cardiovascular risk factor optimization. 1, 8, 6
• Consider single antiplatelet therapy (aspirin or clopidogrel) for long-term prevention. 1
• Encourage minimum 10 minutes of moderate-intensity aerobic activity 4 times weekly in capable patients. 6

Selective Revascularization

• Consider revascularization in asymptomatic patients with high-risk features (such as contralateral carotid occlusion, rapidly progressive stenosis, or vulnerable plaque morphology) and life expectancy >5 years. 4, 9
• Based on CREST-2 findings, if revascularization is pursued in asymptomatic patients, stenting may be preferred over endarterectomy. 7

Post-Intervention Management

Antiplatelet Therapy

• After CEA: Discontinue clopidogrel and continue long-term single antiplatelet therapy (aspirin or clopidogrel). 4
• After stenting: Continue DAPT with aspirin and clopidogrel for at least 1 month, then transition to long-term single antiplatelet therapy. 1, 3

Surveillance Protocol

• Perform DUS surveillance within the first month after any revascularization procedure to assess for complications or restenosis. 1, 2, 3
• Conduct annual follow-up to assess neurological symptoms, cardiovascular risk factors, and medication adherence. 1, 2

Critical Pitfalls to Avoid

• Never dismiss CTA findings based solely on negative Doppler studies—CTA visualizes anatomic lesions directly while Doppler provides hemodynamic assessment; intracranial ICA thrombosis may be visible on CTA but missed by carotid Doppler. 2
• Do not delay intervention in symptomatic patients while pursuing additional imaging—the stroke risk is highest in the first few weeks, and CEA should be performed within 14 days when indicated. 2, 4
• Avoid using the ECST method for stenosis quantification, as it overestimates severity compared to NASCET and creates confusion between imaging modalities. 1, 2
• Do not withhold revascularization based solely on contralateral carotid occlusion—this is a high-risk feature that may actually increase the benefit of CEA in symptomatic patients. 4