What is the recommended management for carotid artery disease with less than 50% stenosis?

Management of Carotid Artery Disease with <50% Stenosis

Revascularization (either carotid endarterectomy or carotid artery stenting) is not recommended for patients with carotid stenosis less than 50%, regardless of whether they are symptomatic or asymptomatic. 1

Primary Recommendation: Medical Management Only

The evidence is unequivocal across all major guidelines: patients with <50% carotid stenosis should receive optimal medical therapy (OMT) alone, without surgical or endovascular intervention. 1

• Revascularization provides no benefit when stenosis is <50% by NASCET criteria, even in symptomatic patients who have experienced stroke or TIA. 1
• The 2024 ESC Guidelines explicitly state: "Revascularization is not recommended in patients with ICA lesions <50%" (Class III recommendation, Level A evidence). 1
• The 2011 multi-society American guidelines similarly conclude: "Except in extraordinary circumstances, carotid revascularization by either CEA or CAS is not recommended when atherosclerosis narrows the lumen by less than 50%" (Class III: No Benefit, Level A). 1

Optimal Medical Therapy Components

All patients with carotid stenosis <50% require aggressive cardiovascular risk factor modification: 1, 2

Antiplatelet Therapy

• For symptomatic patients (those with recent TIA or stroke): Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel 75 mg is recommended for the first 21 days, followed by single antiplatelet therapy (SAPT) long-term. 1
• For asymptomatic patients: Single antiplatelet therapy with aspirin 75-325 mg daily or clopidogrel 75 mg daily. 1

Lipid Management

• Statin therapy is mandatory for all patients with carotid atherosclerosis, targeting aggressive LDL reduction. 2
• Statins improve outcomes after any vascular event and reduce stroke risk. 1, 2

Blood Pressure Control

• Aggressive hypertension management with ACE inhibitors or ARBs as first-line agents. 2
• Target blood pressure should follow current cardiovascular guidelines for secondary prevention if symptomatic. 2

Lifestyle Modifications

• Smoking cessation is critical, as smoking is a major modifiable risk factor. 2
• Diabetes management and lifestyle interventions including diet and exercise. 2

Surveillance Strategy

Initial Assessment

• Duplex ultrasound (DUS) is the recommended first-line imaging modality to establish baseline stenosis severity. 1
• Use NASCET method or its non-invasive equivalent for stenosis quantification. 1

Follow-Up Protocol

• Annual follow-up is recommended to assess cardiovascular risk factors and treatment compliance. 1
• Yearly neurological symptom assessment to detect any progression to symptomatic disease. 1
• Repeat DUS imaging should be considered if symptoms develop or at intervals determined by clinical judgment and progression risk. 1

Critical Pitfalls to Avoid

Do not perform revascularization based solely on stenosis percentage <50%, even if:

• The patient has had a TIA or minor stroke (the stenosis itself is not the indication). 1
• The plaque appears "high-risk" on imaging (ulcerated, irregular). 1
• The patient has contralateral occlusion or other anatomic concerns. 1

Recognize that symptomatic patients with <50% stenosis may have had their stroke from other mechanisms (cardioembolism, small vessel disease, other embolic sources) rather than the carotid plaque itself. 3

The 50% threshold is absolute: Historical trials (NASCET, ECST) demonstrated no benefit from surgery below this threshold, and this finding has remained consistent across decades of follow-up. 1, 3

When to Reassess

Patients should be instructed to seek urgent medical attention if they develop new neurological symptoms, as this would change management considerations. 3

If stenosis progresses to ≥50% on surveillance imaging and the patient becomes symptomatic, or if stenosis reaches ≥70% even if asymptomatic, revascularization should then be reconsidered by a multidisciplinary vascular team. 1, 4