Effect of contralateral occlusion on long-term efficacy of endarterectomy in the asymptomatic carotid atherosclerosis study (ACAS). ACAS Investigators.

Academic Article


  • BACKGROUND AND PURPOSE: The Asymptomatic Carotid Atherosclerosis Study (ACAS) established the effectiveness of prophylactic carotid endarterectomy, for patients in good health who had stenosis >/=60%, if conducted by surgeons with a surgical morbidity and mortality of <3%. This secondary analysis was performed to determine whether the presence of contralateral cervical carotid occlusion alters the efficacy of asymptomatic ipsilateral carotid endarterectomy. METHODS: One hundred sixty-three participants who had a baseline contralateral occlusion documented by Doppler ultrasound (77 medical, 86 surgical) were compared with 1485 participants with a patent contralateral carotid artery (748 medical, 737 surgical) for the risk of a combined end point of perioperative (30-day) death or stroke or long-term (5-year) ipsilateral stroke. RESULTS: For those without contralateral occlusion, surgery was associated with a 6.7% absolute reduction in the 5-year risk (95% CI, 2.1% to 11.4%), while for those with a contralateral occlusion, surgery was associated with a 2.0% absolute increase in risk (95% CI, -9.3% to 5.2%), which was a statistically significant difference in the effect of surgery (P:=0.047). This difference is primarily attributable to low long-term risk for medically managed patients with contralateral occlusion. CONCLUSIONS: While this post hoc analysis should be interpreted with caution, the findings suggest that endarterectomy in asymptomatic subjects with contralateral occlusion provides no long-term benefit (and may be harmful) in preventing stroke and death. These findings were a result of the benign course of medically treated subjects.
  • Published In

  • Stroke  Journal
  • Keywords

  • Aged, Arteriosclerosis, Aspirin, Carotid Stenosis, Disease-Free Survival, Endarterectomy, Carotid, Female, Humans, Male, Predictive Value of Tests, Risk Assessment, Stroke, Survival Rate, Time, Treatment Outcome, Ultrasonography
  • Author List

  • Baker WH; Howard VJ; Howard G; Toole JF
  • Start Page

  • 2330
  • End Page

  • 2334
  • Volume

  • 31
  • Issue

  • 10