A patient with three episodes of transient left‑eye amaurosis fugax over the past two months and a 50 % stenosis of the left internal carotid artery at the bulb—what is the appropriate management?

Management of Recurrent Amaurosis Fugax with 50% Carotid Stenosis

This patient requires immediate transfer to a certified stroke center for comprehensive stroke protocol evaluation within 24 hours, followed by aggressive medical management with antiplatelet therapy, statin therapy, and risk factor optimization—surgical intervention is not indicated at this degree of stenosis. 1, 2

Immediate Actions (Within 24 Hours)

Emergency Referral

• Transfer the patient directly to a certified stroke center or emergency department immediately without delay for additional testing 1, 2
• The risk of stroke is highest within the first 7 days after amaurosis fugax and remains elevated for 30 days 1, 2
• Up to 24% of patients with retinal artery occlusions have concurrent silent brain infarctions on imaging 1, 2

Urgent Diagnostic Workup at Stroke Center

• Brain MRI with diffusion-weighted imaging (DWI) to identify silent cerebral infarctions, which occur in 19-25% of patients despite transient symptoms 3, 1
• Comprehensive vascular imaging of the carotid arteries using duplex ultrasound, CTA, or MRA to confirm the degree of stenosis and exclude higher-grade lesions 3, 1
• Cardiac evaluation including ECG, at least transthoracic echocardiography, and cardiac rhythm monitoring to identify cardioembolic sources 3, 1
• Laboratory studies including ESR and CRP if the patient is over 50 years old to exclude giant cell arteritis 1

Rationale for Medical (Not Surgical) Management

Stenosis Threshold for Intervention

• Carotid endarterectomy is indicated for symptomatic stenosis ≥70% by angiography or ≥50% by ultrasound criteria 3
• At 50% stenosis, this patient falls below the threshold for surgical benefit demonstrated in major trials 3
• The benefit of carotid endarterectomy in symptomatic patients is greatest when stenosis exceeds 70%, with diminishing returns at lower grades 3, 1

Recurrent Episodes and Risk Stratification

• The three episodes over two months indicate crescendo TIAs, which warrant hospitalization if presenting within 72 hours of the most recent event 3
• With multiple vascular risk factors, this patient's 3-year stroke risk could be as high as 24.2%, emphasizing the need for aggressive secondary prevention 1, 2

Comprehensive Medical Management

Antiplatelet Therapy

• Initiate dual antiplatelet therapy (aspirin plus clopidogrel) for 21 days, followed by long-term single antiplatelet agent 1
• This approach is reasonable for patients presenting with minor stroke or high-risk TIA 1

Lipid Management

• Start high-intensity statin therapy immediately as part of vascular secondary prevention, regardless of baseline lipid levels 1

Blood Pressure Control

• Optimize blood pressure management to target levels appropriate for secondary stroke prevention 3, 1

Additional Risk Factor Modification

• Smoking cessation is essential, as smoking is a significant modifiable risk factor 1, 2
• Optimize control of diabetes if present 1
• Address hyperlipidemia aggressively 1

Follow-Up and Monitoring

Neurology Follow-Up

• Arrange outpatient neurology follow-up within 2 weeks after discharge to review imaging results and optimize secondary prevention strategies 3, 2

Ophthalmologic Monitoring

• Monitor for development of iris or retinal neovascularization; if present, consider panretinal photocoagulation with or without anti-VEGF therapy 1

Repeat Vascular Imaging

• Consider repeat carotid imaging in 3-6 months to assess for progression of stenosis, as progression to ≥70% would change management to surgical intervention 3

Critical Pitfalls to Avoid

Time-Sensitive Considerations

• Do not delay emergency referral to perform additional ophthalmologic workup—only one-third of ophthalmologists currently transfer these patients immediately despite guideline recommendations 2
• If stenosis were ≥70%, the benefit of carotid endarterectomy is greatest within 2 weeks of symptom onset and diminishes significantly after 4 weeks in women and 12 weeks in men 1, 2

Diagnostic Errors

• Do not overlook giant cell arteritis in patients over 50 years old presenting with visual symptoms—this requires immediate high-dose corticosteroids to prevent bilateral blindness 1, 2
• Do not miss silent brain infarctions on MRI that may be present despite transient symptoms 1, 2
• Do not confuse amaurosis fugax with transient visual obscurations (TVOs), which last only seconds and represent optic nerve head ischemia from raised intracranial pressure 2

Underestimating Cardiovascular Risk

• Patients with amaurosis fugax carry the same cardiovascular risk as those with cerebral TIA and require equally aggressive secondary prevention 2
• The risk of permanent blindness in the affected eye from subsequent episodes is significant 1, 2

Special Consideration: Ulcerated Plaque

• Even at 50% stenosis, if imaging reveals an ulcerated plaque, the embolic risk is substantially higher 4
• Ulcerated plaques have a high correlation (0.87) with amaurosis fugax and may warrant more aggressive monitoring or consideration of intervention at lower stenosis thresholds 4
• Ensure that vascular imaging specifically comments on plaque morphology and the presence of ulceration 4