In patients with high-grade (≥70%) asymptomatic carotid artery stenosis, what does the CREST‑2 trial demonstrate about the comparative effectiveness and safety of carotid artery stenting versus carotid endarterectomy?

CREST-2 Trial: Carotid Stenting vs CEA in Asymptomatic Carotid Stenosis

In patients with high-grade (≥70%) asymptomatic carotid stenosis, CREST-2 demonstrated that carotid artery stenting (CAS) plus intensive medical management significantly reduced the 4-year risk of stroke compared to medical therapy alone, while carotid endarterectomy (CEA) did not achieve statistical significance—though this likely reflects control group variability rather than true treatment differences.

Key CREST-2 Findings

The CREST-2 trial randomized 2,485 carefully selected, low-risk patients with asymptomatic ≥70% carotid stenosis into two parallel trials 1, 2:

Primary Endpoint Results (4-year periprocedural stroke/death or ipsilateral ischemic stroke):

• CAS + Intensive Medical Management: 2.8% vs Medical Management alone: 6.0% (p=0.02) - statistically significant benefit 2
• CEA + Intensive Medical Management: 3.7% vs Medical Management alone: 5.3% (p=0.24) - not statistically significant 1

Critical Context on These Results:

The divergent outcomes between CAS and CEA likely stem from control group variability rather than true differential efficacy. When investigators created an aggregated control group (combining both medical management arms, n=1,252), the results showed 2:

• CAS achieved 50.4% relative risk reduction (absolute risk reduction 2.85%, number-needed-to-treat 35, p=0.0089)
• CEA showed 1.95% absolute risk reduction (p=0.0871, still not reaching significance but trending toward benefit)

Exceptionally Low Periprocedural Risk

A crucial caveat: CREST-2's periprocedural complication rates were extraordinarily low (1.3-1.5%) due to highly selected patients and expert operators 1. This is well below typical real-world rates and even below current guideline thresholds. Many high-risk anatomic and clinical features were excluded, making these results difficult to generalize to average practice.

Clinical Interpretation for Practice

For Asymptomatic Carotid Stenosis ≥70%:

Intensive medical management should be the cornerstone for most patients 1, 3, 4. The medical therapy arms achieved remarkably low stroke rates (5.3-6.0% at 4 years), demonstrating that modern medical therapy is highly effective.

When to Consider Revascularization:

Based on CREST-2 and existing guidelines 5, 6, 7, revascularization may be reasonable when:

1. Patient has >70% stenosis with favorable anatomy
2. Life expectancy >5 years
3. Low perioperative risk profile (no severe comorbidities)
4. Procedure performed at high-volume center with documented periprocedural stroke/death rates <2% for asymptomatic patients 8
5. Patient is highly motivated and understands risks/benefits

Choosing Between CAS and CEA:

When revascularization is pursued, selection should consider 5, 7:

Favor CEA when:

• Patient age >70 years (CEA safer in elderly) 5, 7
• Unfavorable anatomy for endovascular approach (heavily calcified aortic arch, protruding atheroma, internal carotid diameter <3mm) 9
• Standard surgical anatomy

Favor CAS when:

• Unfavorable neck anatomy for surgery (high cervical lesion above C2, intrathoracic lesion, previous CEA, radiation-induced stenosis, contralateral vocal cord paralysis, tracheostomy) 5, 10
• Significant cardiovascular comorbidities increasing surgical risk 7
• Patient age <70 years 5

Important Limitations and Real-World Application

CREST-2 Limitations 1, 11:

1. Highly selected, low-risk patients - excluded many typical real-world patients
2. Expert operators only - results may not translate to average-volume centers
3. Medical therapy targets often missed in all four study groups
4. Short follow-up - longer follow-up may show CEA benefit emerging 11
5. Fragile statistical significance for CAS benefit

Common Pitfalls to Avoid:

• Do not routinely offer revascularization to all asymptomatic patients with ≥70% stenosis
• Do not perform procedures at centers with periprocedural complication rates exceeding 2% for asymptomatic patients 8
• Do not ignore age - patients >70 years have worse outcomes with CAS 5, 7
• Do not neglect intensive medical management - this is non-negotiable regardless of whether revascularization is performed

Optimal Medical Therapy Components

All patients with asymptomatic carotid stenosis require 6, 7:

• Aspirin 81-325mg daily
• High-intensity statin therapy
• Blood pressure control (target <140/90 mmHg, lower if tolerated)
• Diabetes management if present
• Smoking cessation
• Lifestyle modifications (diet, exercise)

Guideline Context

Current guidelines predate CREST-2 but remain relevant 5, 6, 7:

• Class IIa recommendation: CEA is reasonable for asymptomatic patients with >70% stenosis if perioperative risk <3% (now arguably should be <2%)
• Class IIb recommendation: CAS might be considered in highly selected patients, but effectiveness vs medical therapy alone was previously "not well established" - CREST-2 now provides Level A evidence for CAS benefit
• Class I recommendation: Selection should be guided by comorbidities, life expectancy, and thorough risk-benefit discussion

The most recent ESC consensus (2025) emphasizes that modern medical therapy may reduce but does not abolish stroke risk, and periprocedural rates should not exceed 2% for asymptomatic stenoses 8.