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Journal Club

Cerebrovascular

Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis

N Engl J Med | 1991

Rapid review note

Journal Club is a rapid, AI-assisted appraisal layer. It highlights study design, effect estimates, and practice relevance, but it is still a briefing, not a replacement for the paper.

For education only. Not medical advice.

Paper snapshot

Rapid study overview

Open paper

DOI

10.1056/NEJM199108153250701

PMID

1852179

PICO

Population

patients with carotid artery stenosis

Intervention

carotid endarterectomy

Comparator

medical management

Outcomes

stroke prevention

Design

Type

randomized controlled trial

Randomized

Yes

Multicenter

N/A

Blinded

N/A

Follow-up

N/A

Primary endpoint

stroke prevention

Secondary endpoints

  • Secondary endpoints require direct verification from full text.

Practice impact

What this means

NASCET is the landmark proof that carotid endarterectomy benefits patients with recently symptomatic high-grade carotid stenosis. The core teaching point is not just that surgery helps, but that it helps when stenosis is severe, symptoms are recent, and perioperative complication rates stay low.

Bottom line

For recently symptomatic 70-99% carotid stenosis, carotid endarterectomy provides clear stroke-reduction benefit when performed with acceptably low perioperative risk.

Strength of evidence

high

Recommendation

change practice

Why it matters

  • The absolute stroke reduction in high-grade symptomatic stenosis is large enough to outweigh procedural risk in experienced hands.
  • This trial established symptomatic high-grade carotid stenosis as a surgical disease rather than a medical-management-only problem.
  • The practical lesson remains tightly linked to perioperative quality and patient selection.

What would change my mind

  • A validated full-text appraisal with explicit effect estimates and page-linked citations.

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Randomization supports causal inference, but the trial was conducted in an era before current medical therapy, and operative outcomes depend heavily on maintaining low perioperative stroke and death rates.

Confounding

Random assignment should minimize baseline confounding, though center-level operative skill remains an important effect modifier for real-world applicability.

Missing data

The landmark result is driven by event follow-up over time; any attrition appears limited in the published trial reports, but long-term estimates still depend on consistent surveillance.

Multiplicity

The key inference comes from the prespecified high-grade stenosis comparison; secondary subgroup and longer-term analyses should be interpreted as supportive rather than primary proofs.

Notes

  • Automated fallback entry: upgrade with full appraisal if model generation fails.

Stats check

NNT

Approximate NNT 6 over 2 years for symptomatic 70-99% stenosis.

Effect sizes

  • Any ipsilateral stroke at 2 years was about 9% with endarterectomy versus 26% with medical therapy, an absolute reduction of roughly 17 percentage points.
  • Major or fatal ipsilateral stroke was reduced by about 10.6 percentage points at 2 years in the surgically treated group.
  • Perioperative stroke or death was approximately 5.8%, making procedural safety central to net benefit.

Absolute effects

  • Roughly 1 ipsilateral stroke was prevented over 2 years for every 6 symptomatic patients with 70-99% stenosis treated surgically rather than medically.
  • The event curves separated early after treatment and remained apart through follow-up in the high-grade stenosis cohort.
  • Benefit was shown for recently symptomatic high-grade carotid stenosis rather than lower-risk carotid disease in general.

Concerns

  • The net benefit depends on keeping perioperative stroke and death rates low enough to preserve the long-term stroke reduction.
  • The trial predates contemporary statin-intensive medical therapy, so absolute benefit today may differ from the original estimate.
  • The result applies to recently symptomatic high-grade stenosis, not automatically to moderate or asymptomatic disease.

External validity

Who it applies to

Patients similar to the study population once inclusion criteria are verified.

Who it does not

Patients outside the verified eligibility criteria.

Generalizability notes

  • Patient characteristics and inclusion/exclusion criteria unknown
  • Treatment protocols and follow-up duration unclear

Evidence trace

Source trace and metadata

Citations (3)

claim_id

methods_critique.risk_of_bias

locator

p. 1

claim_id

stats_check.concerns

locator

p. 1

claim_id

practice_impact.bottom_line

locator

p. 1

Metadata

Generated at

2026-03-09T22:35:10.673Z

Version

pdf-archive-ingest-v1