Endarterectomy for Asymptomatic Carotid Stenosis?

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Endarterectomy for Asymptomatic Carotid Stenosis?

Results suggest a striking benefit of carotid endarterectomy, with some caveats.

The precise risk-benefit ratio for carotid endarterectomy (CEA) in patients with substantial, asymptomatic carotid-artery stenosis remains elusive. In two U.S. trials (N Engl J Med 1993; 328:221 and JAMA 1995; 273:1421), CEA reduced the risk for transient ischemic attack or nondisabling stroke, but not for fatal or disabling stroke.

Researchers in Europe randomized 3120 asymptomatic patients (mean age, 68; 34% women) with $≥$ 60% carotid stenosis on ultrasound to immediate CEA (50% underwent CEA by 1 month, 88% by 1 year) or to indefinite deferral of CEA (6% underwent CEA by 1 year). Both groups received intensive medical therapy throughout a 5-year follow-up.

The overall risk for death or stroke within 30 days of CEA was 3.1%. The 5-year risk for nonperioperative stroke was significantly lower with immediate CEA than with indefinite deferral of CEA (3.8% vs. 10.9%); most of the difference was accounted for by carotid-territory ischemic strokes (2.7% vs. 9.5%), of which more than half were disabling or fatal (1.6% vs. 5.3%). When perioperative and nonperioperative events were combined, immediate CEA still showed a significant overall advantage over CEA deferral for stroke or death (6.4% vs. 11.8%) and for fatal or disabling stroke (3.5% vs. 6.1%).

Immediate CEA benefited patients with <80% stenosis (mean, 69%) and those with $≥$ 80% stenosis (mean, 87%). Patients younger than 75 benefited, but patients 75 or older did not (many died from unrelated causes).

Comment: "Immediate" CEA reduced 5-year stroke risk by about half in asymptomatic patients younger than 75 with carotid stenosis of about 70% or greater -- a benefit that counters the 3% perioperative risk and includes significant prevention of disabling or fatal stroke. Moreover, divergence over time in carotid-stroke risk in the two treatment groups suggests that benefits from CEA could be even larger by 10-year follow-up. Despite these striking findings, research still must identify precisely which asymptomatic patients are at highest risk and must further optimize medical therapy before routine ultrasound screening can be recommended. As the authors note, CEA still has the potential for misuse in asymptomatic patients in practice (e.g., due to poor performance of surgery and inappropriate selection of patients because of imprecise ultrasound evaluation).

— Beat J. Meyer, MD

Published in Journal Watch Cardiology July 23, 2004

Citation(s):

MRC Asymptomatic Carotid Surgery Trial (ACST) Collaborative Group. Prevention of disabling and fatal strokes by successful carotid endarterectomy in patients without recent neurological symptoms: Randomised controlled trial. Lancet 2004 May 8; 363:1491-502.