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Neurology Clinical Trial Database

CREST-2

Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trials

Year of Publication: 2025

Authors: T.G. Brott, G. Howard, B.K. Lal, ..., for the CREST-2 Investigators

Journal: New England Journal of Medicine

Citation: Brott TG, Howard G, Lal BK, et al. Medical Management and Revascularization for Asymptomatic Carotid Stenosis. N Engl J Med 2025. DOI: 10.1056/NEJMoa2508800

Link: https://www.nejm.org


Clinical Question

Among patients with asymptomatic high-grade carotid stenosis, does adding carotid revascularization (stenting or endarterectomy) to intensive medical management provide greater benefit than intensive medical management alone in preventing stroke?

Bottom Line

In patients with asymptomatic high-grade carotid stenosis, carotid-artery stenting plus intensive medical management significantly reduced the 4-year risk of stroke or death compared to intensive medical management alone (2.8% vs 6.0%, P=0.02, NNT=31). Carotid endarterectomy plus intensive medical management did not show a significant benefit compared to medical management alone (3.7% vs 5.3%, P=0.24).

Major Points

  • Two parallel randomized observer-blinded trials comparing revascularization plus intensive medical management versus intensive medical management alone
  • Stenting trial showed significant benefit with 3.2 percentage point absolute risk reduction (P=0.02)
  • Endarterectomy trial did not reach statistical significance with 1.6 percentage point absolute risk reduction (P=0.24)
  • Intensive medical management achieved excellent risk factor control across all groups (BP <130 mmHg, LDL <70 mg/dL)
  • Periprocedural stroke/death rates were low: 1.3% for stenting and 1.5% for endarterectomy
  • Post-procedural ipsilateral stroke rates strongly favored revascularization in both trials
  • All treatment groups, including medical therapy alone, had low rates of disabling stroke
  • Crossover rates were 17-18% from medical therapy to revascularization

Design

Study Type: Two parallel, observer-blinded, randomized controlled trials

Randomization: 1

Blinding: Observer-blinded (stroke adjudicators unaware of treatment assignment). Patients and treating physicians were not blinded

Enrollment Period: December 2014 to July 2025 (stenting trial), December 2014 to September 2024 (endarterectomy trial)

Follow-up Duration: Median 3.6 years (IQR 1.6-4.0) for stenting trial, median 4.0 years (IQR 2.0-4.0) for endarterectomy trial, up to 4 years maximum

Centers: 155

Countries: United States, Canada, Australia, Israel, Spain

Sample Size: 2485

Analysis: Intention-to-treat analysis. Kaplan-Meier curves for event rates with cumulative-incidence function accounting for competing risk of death. Assumption-free re-randomization test with 10,000 replications for significance testing. Bootstrap methods with 100,000 replications for 95% confidence intervals. Poisson regression for annual event rates. O'Brien-Fleming boundaries for interim analysis with final alpha=0.047


Inclusion Criteria

  • Age ≥35 years
  • No history of stroke, transient ischemic attack, or amaurosis fugax in carotid territory within 180 days before randomization
  • Stenosis ≥70% assessed by duplex ultrasound with peak systolic velocity ≥230 cm/sec AND one of: end diastolic velocity ≥100 cm/sec, peak systolic velocity ratio (ICA/CCA) ≥4.0, or ≥70% stenosis on CTA or MRA
  • OR stenosis ≥70% on catheter angiography alone

Exclusion Criteria

  • Previous disabling stroke
  • Unstable angina
  • Atrial fibrillation prompting anticoagulation
  • Additional eligibility criteria specific to stenting versus endarterectomy determined by trial site

Arms

FieldControlStenting Trial - Carotid-Artery StentingControlEndarterectomy Trial - Carotid Endarterectomy
InterventionIntensive medical management with protocol-driven oversight. Primary targets: systolic BP <130 mmHg (changed from <140 mmHg in 2018), LDL cholesterol <70 mg/dL. Management of glucose, glycated hemoglobin, lifestyle factors (smoking cessation, weight management, physical activity). Telephone health coaching. Antiplatelet therapy per standard care. Free medications available including alirocumab after 2018Transfemoral carotid-artery stenting with embolic protection (required) plus intensive medical management. Local anesthesia for femoral access with or without conscious sedation. Antiplatelet regimen: aspirin 325 mg daily plus clopidogrel 75 mg twice daily starting 48 hours before procedure, then clopidogrel 75 mg daily plus aspirin 75-325 mg daily for 30 days, followed by aspirin 70-325 mg daily thereafter. Alternative antiplatelet regimens if clopidogrel/aspirin contraindicatedIntensive medical management with protocol-driven oversight. Primary targets: systolic BP <130 mmHg (changed from <140 mmHg in 2018), LDL cholesterol <70 mg/dL. Management of glucose, glycated hemoglobin, lifestyle factors (smoking cessation, weight management, physical activity). Telephone health coaching. Antiplatelet therapy per standard care. Free medications available including alirocumab after 2018Carotid endarterectomy plus intensive medical management. General anesthesia in 89% of cases. Antiplatelet regimen: aspirin 325 mg daily for at least 48 hours before procedure, then aspirin 70-325 mg daily thereafter. Periprocedural anticoagulation with heparin or bivalirudin required
Duration4 years4 years4 years4 years

Outcomes

OutcomeTypeControlInterventionHR / OR / RRP-value
4-year composite of any stroke (ischemic or hemorrhagic) or death assessed from randomization to 44 days (periprocedural period), or ipsilateral ischemic stroke assessed during remaining follow-up up to 4 years (postprocedural period)Primary31Stenting trial: P=0.02. Endarterectomy trial: P=0.24
Periprocedural stroke or death (days 0-44) - Stenting trialSecondary8/616 (1.3%, 95% CI 0.6-2.5)Difference -1.3% (95% CI -2.2 to 0.4)
Periprocedural stroke or death (days 0-44) - Endarterectomy trialSecondary9/617 (1.5%, 95% CI 0.7-2.8)Difference -1.0% (95% CI -2.1 to 0.1)
Postprocedural ipsilateral ischemic stroke (annual rate) - Stenting trialSecondary0.4% per year (95% CI 0.2-0.9), 7 events/1714 person-yearsRR 4.07 (95% CI 1.78-9.31)Not reported
Postprocedural ipsilateral ischemic stroke (annual rate) - Endarterectomy trialSecondary0.5% per year (95% CI 0.3-1.0), 10 events/1823 person-yearsRR 2.38 (95% CI 1.13-5.00)Not reported
Tissue-based stroke definitions (4-year composite)SecondaryResults similar to primary outcome with WHO-defined strokeNot reported
Nondisabling stroke outcomesSecondaryConcordant with primary outcome in both trialsNot reported
Disabling strokeSecondaryLow rates in all groupsNot reported
Death - Stenting trialAdverse48 (7.8%)Not reported
Death - Endarterectomy trialAdverse54 (8.8%)Not reported
Carotid revascularization - Stenting trialAdverse29 (4.7%)Not reported
Carotid revascularization - Endarterectomy trialAdverse44 (7.1%)Not reported
No revascularization received when assigned - Stenting trialAdverse41 (7%)Not applicable
No revascularization received when assigned - Endarterectomy trialAdverse24 (4%) - 22 no procedure, 2 received stenting insteadNot applicable

Subgroup Analysis

Eleven prespecified subgroups analyzed including age (<70, ≥70, <80, ≥80), sex, peak systolic velocity (<342, ≥342 cm/sec), hypertension, diabetes, dyslipidemia, smoking, CHA2DS2-VASc score (0-3, ≥4), symptomatic status of target artery, symptomatic status of contralateral artery. Results appeared consistent across subgroups in both trials. Median infarct volume was 1.55 mL (IQR 0.27-7.81) and appeared similar between treatment groups in both trials


Criticisms

  • Unblinded design - patients and treating physicians aware of treatment assignment, though stroke adjudicators were blinded
  • Changes in medical therapy practices during trial period may have lowered stroke rates and affected relative benefit of revascularization
  • Results may not generalize to broader practice as revascularization performed only by well-trained, certified, high-volume operators with validated credentialing
  • Transcarotid-artery revascularization came into use after approximately half of patients enrolled and could not be incorporated
  • Tipping-point analysis showed stenting trial significance could be affected by change in outcome of 3-4 patients (>10% relative change in events)
  • Some postprocedural strokes may not have been causally related to carotid revascularization as it does not prevent all stroke mechanisms
  • Crossover rates of 17-18% from medical therapy to revascularization may have diluted treatment effect
  • Limited power in endarterectomy trial to detect difference - tipping point analysis suggested significance would require 6-7 additional events in medical therapy group
  • Follow-up duration limited to median 3.6-4.0 years - longer-term outcomes unknown
  • Relatively small absolute number of events despite large sample size

Funding

National Institute of Neurological Disorders and Stroke (grants U01 NS080168, U01 NS080165), Centers for Medicare and Medicaid Services, NIH StrokeNet (grant U01 NS086872). Alirocumab donated by Regeneron Pharmaceuticals after 2018

Based on: CREST-2 (New England Journal of Medicine, 2025)

Authors: T.G. Brott, G. Howard, B.K. Lal, ..., for the CREST-2 Investigators

Citation: Brott TG, Howard G, Lal BK, et al. Medical Management and Revascularization for Asymptomatic Carotid Stenosis. N Engl J Med 2025. DOI: 10.1056/NEJMoa2508800

Reviewed by: Ahmed Koriesh, MD

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