What is the recommended management for a patient with less than 50% stenosis of the left internal carotid artery (ICA)?

Management of <50% Stenosis of the Left Internal Carotid Artery

For patients with less than 50% stenosis of the left internal carotid artery (ICA), medical management without revascularization is strongly recommended as the appropriate treatment approach. 1

Medical Management Recommendations

• Optimal medical therapy (OMT) is the cornerstone of management for patients with <50% stenosis of the left ICA 1
• Antiplatelet therapy should be initiated for all patients with carotid stenosis to reduce stroke risk 1
• For patients with symptomatic carotid stenosis (recent stroke/TIA), dual antiplatelet therapy (DAPT) with low-dose aspirin and clopidogrel (75 mg) is recommended for at least 21 days, followed by single antiplatelet therapy 1
• Statin therapy should be implemented for all patients with carotid stenosis to stabilize plaques and reduce stroke risk 1
• Aggressive risk factor modification including blood pressure control, smoking cessation, and diabetes management should be pursued 1

Evidence Against Revascularization

• The American Heart Association/American Stroke Association explicitly states that when the degree of stenosis is <50%, there is no indication for carotid revascularization by either carotid endarterectomy (CEA) or carotid artery stenting (CAS) (Class III, Level of Evidence A) 1
• The European Society of Cardiology guidelines (2024) reinforce that revascularization is not recommended in patients with ICA lesions <50% 1
• Clinical trials have consistently shown no benefit of surgical intervention for patients with <50% stenosis 1, 2

Follow-up Recommendations

• Annual follow-up is recommended to monitor for:
  • Development of new neurological symptoms 1
  • Progression of stenosis 1
  • Cardiovascular risk factor control 1
  • Medication adherence 1
• Duplex ultrasound (DUS) surveillance should be performed periodically to assess for progression of stenosis 1

Important Considerations and Pitfalls

• Even though revascularization is not indicated for <50% stenosis, these patients still require aggressive medical management to prevent stroke 1
• The NASCET method (or non-invasive equivalent) should be used to assess and monitor the degree of ICA stenosis 1
• Duplex ultrasound (DUS) is the recommended first-line imaging modality for diagnosing and monitoring carotid stenosis 1
• Patients should be educated about the importance of seeking immediate medical attention if they develop symptoms suggestive of TIA or stroke 1
• The risk of stroke in patients with asymptomatic carotid stenosis treated medically is approximately 2% per annum, and this risk is even lower with modern medical therapy 2

Special Circumstances

• For patients with <50% stenosis who become symptomatic (develop TIA or stroke), reassessment of the degree of stenosis is warranted as disease progression may have occurred 1
• In patients with multiple risk factors or evidence of progressive stenosis, more frequent monitoring may be appropriate 1, 3