Should patients with asymptomatic Carotid Artery Stenosis (CAS) undergo Carotid Endarterectomy (CEA) during Coronary Artery Bypass Grafting (CABG)?

Management of Asymptomatic Carotid Artery Stenosis During CABG

Routine prophylactic CEA during CABG for asymptomatic unilateral carotid stenosis is NOT recommended, as isolated CABG should be performed in these patients due to the small absolute stroke risk reduction (approximately 1% per year) that cannot justify the added perioperative risk of combined procedures. 1

Evidence-Based Approach by Stenosis Pattern

Unilateral Asymptomatic Carotid Stenosis (70-99%)

• Perform CABG alone without carotid revascularization - this is the standard approach supported by European Society of Cardiology guidelines, as the perioperative stroke risk with unilateral asymptomatic stenosis is small and does not justify the 9% combined death/stroke rate associated with staged procedures. 1

• The most recent randomized trial (CABACS, 2022) demonstrated that combined CABG+CEA resulted in higher rates of stroke or death at 5 years (40.6%) compared to CABG alone (35.0%), though this difference was not statistically significant due to early termination. 2

• Nonfatal stroke rates were consistently higher (though not statistically significant) following CABG+CEA versus CABG alone at 1 year (19.3% vs 7.1%) and 5 years (29.4% vs 18.8%). 2

High-Risk Asymptomatic Patterns Requiring Consideration of Carotid Revascularization

Consider carotid revascularization (Class IIb recommendation) ONLY in men with: 1

• Bilateral 70-99% carotid stenosis, OR
• 70-99% unilateral stenosis with contralateral occlusion, OR
• 70-99% stenosis with ipsilateral silent cerebral infarction on imaging 1

Do NOT perform carotid revascularization in: 1

• Women with asymptomatic carotid stenosis
• Patients with life expectancy <5 years
• Patients with stenosis <70%

Timing Strategy When Revascularization Is Indicated

For Symptomatic Carotid Disease (TIA/Stroke <6 months)

• Carotid revascularization is mandatory (Class I recommendation) for 70-99% stenosis before or simultaneous with CABG. 1

• Target the most symptomatic territory first - if cardiac symptoms are unstable/urgent, consider simultaneous procedures or hybrid approach with CAS immediately before CABG. 1

• Perioperative stroke risk is 8.5% if symptomatic carotid stenosis is left unaddressed during CABG. 1

Staged vs Simultaneous Approach

• Staged procedures (CAS then CABG 4-5 weeks later) should be reserved for very high-risk patients requiring urgent CABG who have previous neurological symptoms, as systematic reviews show a 9% combined death/stroke rate with staged approaches in asymptomatic patients. 1

• If CAS is performed before CABG, mandatory dual antiplatelet therapy delays cardiac surgery by 4-5 weeks, which may be problematic in unstable coronary disease. 1

• Simultaneous CEA+CABG carries a 4.3% combined stroke/mortality rate in asymptomatic patients based on large registry data, which is higher than CEA alone. 3

Operator and Center Requirements

Any carotid revascularization must only be performed by teams demonstrating: 1

• <3% combined 30-day death/stroke rate in asymptomatic patients (Class I requirement)
• <6% combined 30-day death/stroke rate in symptomatic patients

If local expertise cannot meet these benchmarks, perform CABG alone with optimal medical therapy. 1

Choice of Revascularization Method (CEA vs CAS)

CEA Remains Preferred

• CEA is the procedure of choice based on meta-analyses showing CAS results in significantly increased 30-day death or stroke (OR 1.60,95% CI 1.26-2.02). 1

• The International Carotid Stenting Study showed stroke/death/MI rates of 8.5% with CAS versus 5.2% with CEA (HR 1.69, P=0.006). 1

CAS Should Be Considered Only For:

• Post-radiation or post-surgical stenosis
• Hostile neck anatomy (obesity, tracheostomy, laryngeal palsy)
• Stenosis at different carotid levels or upper internal carotid artery
• Severe comorbidities contraindicating CEA 1

Mandatory Medical Therapy Regardless of Revascularization Decision

All patients require intensive medical therapy: 4

• Daily antiplatelet therapy (aspirin 81-325 mg)

• High-intensity statin therapy

• Blood pressure control (target <140/90 mmHg, ACE inhibitors preferred)

• Diabetes management (HbA1c <7%)

• Smoking cessation

• Contemporary best medical therapy has reduced annual stroke risk in asymptomatic severe carotid stenosis to ≤1% per year, which approaches the perioperative risk of intervention itself. 4

Common Pitfalls to Avoid

• Do not routinely screen and revascularize asymptomatic unilateral carotid stenosis - the 2022 CABACS trial and multiple guidelines demonstrate this approach increases rather than decreases stroke risk. 2, 1

• Do not combine CAS with elective PCI during the same endovascular procedure (Class III recommendation) except in rare circumstances of concomitant acute severe carotid and coronary syndromes. 1

• Do not assume all perioperative strokes are carotid-related - aortic clamping/de-clamping and other mechanisms contribute significantly to CABG-related stroke. 1

• Do not proceed with carotid revascularization if operator/center outcomes exceed guideline thresholds - in such cases, CABG alone with optimal medical therapy is safer. 1