Table 1 Inclusion/Exclusion Criteria for Carotid Endarterectomy Trials
| NASCET [9] |
| Inclusion |
| Symptoms of focal cerebral ischemia ipsilateral to a stenosis of <70% (moderate group) or ≥70% (severe group) within 180 days, as shown on angiography |
| Symptoms lasting <24 hours or producing nondisabling stroke (Rankin score <3) |
| Exclusion |
| Age >80 years (initial phase of moderate and severe stenosis; continuing study of moderate stenosis included these patients) |
| Lack of angiographic visualization of symptomatic artery |
| Lack of informed consent |
| Intracranial stenosis more severe than the cervical stenosis |
| Other disease limiting life expectancy to <5 years |
| Cerebral infarction limiting useful function in the affected arterial territory |
| Nonatherosclerotic carotid disease |
| Cardiac lesions likely to cause cardioembolism |
| History of ipsilateral carotid endarterectomy |
| ACAS [8] |
| Inclusion |
| Age 40–79 years |
| Compatible history and findings on physical and neurologic examination |
| Acceptable laboratory and electrocardiogram results |
| Arteriography within the previous 60 days indicating stenosis of at least 60% reduction in diameter (if arteriography performed 61–364 days before randomization, repeat Doppler showing artery still patent) or Doppler examination within 60 days showing a frequency or velocity greater than the instrument-specific cut point with 95% positive predictive value or Doppler examination showing a frequency or velocity greater than the instrument-specific 90% positive predictive value cut point confirmed by ocular pneumoplethysmographic examination within the previous 60 days |
| Exclusion |
| Cerebrovascular event in the distribution of the affected carotid artery or the vertebrobasilar system |
| Symptoms referable to the contralateral cerebral hemisphere within the previous 45 days |
| Contraindication to aspirin therapy |
| Any disorder that could seriously complicate surgery |
| Any condition that could prevent continuing participation or likely to produce death or disability within 5 years |
| Lack of informed consent |