Is carotid artery stenting appropriate for a patient with high‑grade (>70%) asymptomatic carotid stenosis?

Carotid Artery Stenting for High-Grade Asymptomatic Carotid Stenosis

Carotid artery stenting is generally NOT recommended for high-grade asymptomatic carotid stenosis in routine clinical practice, as modern optimal medical therapy alone achieves stroke rates ≤1% per year, and CAS carries a 2.2-4% perioperative stroke/death risk that negates any potential benefit in most asymptomatic patients. 1, 2

Primary Recommendation: Optimal Medical Therapy First-Line

All patients with asymptomatic high-grade carotid stenosis should receive intensive medical management as the foundation of treatment. 1, 3, 2 This includes:

• Daily antiplatelet therapy (aspirin or clopidogrel) 1, 2
• High-intensity statin therapy regardless of baseline lipid levels 3, 2
• Blood pressure control with target <140/90 mmHg 3, 2
• Diabetes management if present 4
• Smoking cessation 3, 2
• Mediterranean-style diet and regular exercise 3

The annual stroke risk with contemporary best medical therapy has fallen to ≤1% per year, compared to 2.2% per year in older trials. 2

When CAS May Be Considered (Highly Selected Cases Only)

CAS may be considered only in highly selected asymptomatic patients with >70% stenosis who meet ALL of the following criteria: 1, 4

Patient Selection Criteria:

• **Age <70 years** (CAS is generally not recommended for patients >70 years due to higher perioperative stroke/death rates) 4, 5
• Life expectancy >5 years 1
• High-risk features present, such as: 4, 2
  • Bilateral 70-99% stenosis
  • Contralateral carotid occlusion
  • Silent cerebral infarction on imaging
  • Rapid stenosis progression
  • Microemboli detection on transcranial Doppler 6
  • Intraplaque hemorrhage on MRI 6

Institutional Requirements:

• Documented center/operator expertise with perioperative stroke/death rates <3% in asymptomatic patients 1, 4
• Routine auditing of performance results 4

Anatomic Considerations Favoring CAS Over CEA:

CAS should be considered preferentially when CEA is high-risk due to: 1, 4

• Post-radiation stenosis
• Post-surgical restenosis
• Hostile neck anatomy (tracheostomy, laryngeal palsy)
• High carotid bifurcation or upper internal carotid artery stenosis
• Severe medical comorbidities contraindicating surgery

Absolute Contraindications to CAS

CAS should NOT be performed in patients with: 1

• Heavily calcified aortic arch or protruding atheroma
• Internal carotid artery lumen diameter <3 mm
• Contraindication to dual antiplatelet therapy (DAPT)

Mandatory Peri-Procedural Requirements if CAS Performed

If CAS is undertaken, the following are mandatory: 1, 4

• DAPT with aspirin and clopidogrel for at least 1 month post-stenting 1
• Embolic protection device use in >90% of cases 7
• Long-term single antiplatelet therapy indefinitely after the initial DAPT period 1

Evidence Against Routine CAS in Asymptomatic Patients

The guideline evidence strongly discourages routine CAS for asymptomatic stenosis: 1

• European Heart Journal guidelines state that carotid revascularization (including CAS) "is not recommended in women or patients with a life expectancy <5 years" for asymptomatic disease 1
• For asymptomatic unilateral disease, the 30-day combined death/stroke rate of 9% with staged procedures "cannot be justified in neurologically asymptomatic patients" 1
• CAS carries a perioperative stroke/death risk of approximately 2.2-4% in asymptomatic patients, compared to 1.5-3% for CEA 2

CEA Remains Preferred Over CAS When Intervention Indicated

When revascularization is deemed necessary for asymptomatic stenosis, CEA remains the procedure of choice over CAS. 1 The European Heart Journal guidelines give CEA a Class I, Level B recommendation, stating "CEA remains the procedure of choice but selection of CEA versus CAS depends on multidisciplinary assessment." 1

CEA may be considered in: 1

• Men with bilateral 70-99% stenosis
• Men with 70-99% stenosis plus contralateral occlusion
• Perioperative stroke/death risk <3%
• Life expectancy >5 years

Follow-Up Strategy

All patients with asymptomatic carotid stenosis require structured surveillance: 1, 2

• Annual duplex ultrasound to assess disease progression 1, 2
• Annual clinical follow-up to assess cardiovascular risk factors and treatment adherence 1
• Patients with stenosis progression ≥2 categories in 1 year are at higher risk and may warrant reconsideration of intervention 2

Critical Pitfalls to Avoid

• Do not offer CAS to patients >70 years old with asymptomatic stenosis—outcomes are inferior to CEA and medical therapy 4, 5
• Do not proceed with CAS if center/operator stroke/death rates exceed 3% in asymptomatic patients—this negates any benefit 1, 4
• Do not use CAS in symptomatic patients as a routine alternative to CEA—symptomatic patients have significantly worse outcomes with CAS (8.3% vs 4.6% combined stroke/mortality compared to CEA) 8
• Do not neglect optimal medical therapy even if intervention is performed—medical management is the foundation regardless of revascularization 1, 3, 2

Contemporary Context

The role of any revascularization (CAS or CEA) for asymptomatic stenosis is increasingly questioned. 2, 9 Modern medical therapy has reduced stroke rates to levels comparable to or better than intervention in many patients. 2, 9 The ongoing CREST-2 trial is comparing CEA and CAS versus intensive medical therapy alone to definitively answer which approach is superior. 9 Until these results are available, optimal medical therapy should be the default approach for most patients with asymptomatic carotid stenosis, with intervention reserved only for the highest-risk subset meeting strict criteria. 2, 9