Aggressive Medical Treatment Evaluation for Asymptomatic Carotid Artery Stenosis (AMTEC)

The aim of this study is to determine whether optimal medical treatment can postpone carotid endarterectomy.

It is well known that risk of fatal and non-fatal stroke is increased in patients with significant carotid atherosclerosis. For asymptomatic patients, AHA guidelines recommend carotid endarterectomy (CEA) for stenosis 60% to 99%, if the risk of perioperative stroke or death is less than 3%.

Although clinical trial data support CEA in asymptomatic patients with carotid stenosis 60% to 79%, the AHA guidelines indicate that some physicians delay revascularization until there is greater than 80% stenosis in asymptomatic patients.

Our study is designed to determine whether optimal medical therapy alone reduces the risk of death and nonfatal stroke in patients with carotid artery stenosis as compared with CEA coupled with optimal medical therapy.

• Carotid Artery Stenosis
• Atherosclerosis
• Stroke

• Procedure: Carotid Endarterectomy
  CEA involves a neck incision and physical removal of the plaque from the inside of the artery
• Drug: atorvastatin, aspirin, losartan, amlodipine
  aspirin 100 mg/day, atorvastatin 10 mg/day, losartan 50 mg/day, amlodipine 5 mg/day

• Experimental: 1
  Patients receive medical treatment including medical therapy with statins (at least 10 mg atorvastatin irrespective of the baseline cholesterol level), aspirin (100 mg daily) and antihypertensive therapy (at least 50 mg losartan and 5 mg amlodipine 75 mg daily irrespective of the baseline arterial pressure level). Further conservative medical treatment includes modification of cardiovascular risk factors according to current recommendations. Additionally patients will undergo CEA.
  Interventions:

  • Procedure: Carotid Endarterectomy
  • Drug: atorvastatin, aspirin, losartan, amlodipine
• Active Comparator: 2
  Patients receive medical treatment including medical therapy with statins (at least 10 mg atorvastatin irrespective of the baseline cholesterol level), aspirin (100 mg daily) and antihypertensive therapy (at least 50 mg losartan and 5 mg amlodipine 75 mg daily irrespective of the baseline arterial pressure level). Further conservative medical treatment includes modification of cardiovascular risk factors according to current recommendations.
  Intervention: Drug: atorvastatin, aspirin, losartan, amlodipine

Inclusion Criteria:

• Unilateral or bilateral carotid artery stenosis that was considered to be severe (carotid artery diameter reduction 70%-79% on ultrasound)
• This stenosis had not caused any stroke, transient cerebral ischaemia, or other relevant neurological symptoms in the past 6 months
• Both doctor and patient were substantially uncertain whether to choose immediate CEA, or deferral of any CEA until a more definite need for it was thought to have arisen
• The patient had no known circumstance or condition likely to preclude long-term follow-up
• Neurologist's explicit consent to potentially perform CEA

Exclusion Criteria:

• Previous ipsilateral CEA
• Expectation of poor surgical risk (e.g., because of recent acute myocardial infarction)
• Some probable cardiac source of emboli (because the main stroke risk might then be from cardiac, not carotid, emboli)
• Inability to provide informed consent
• Underlying disease other than atherosclerosis (inflammatory or autoimmune disease)
• Life expectancy < 6 months
• Advanced dementia
• Advanced renal failure (serum creatinine > 2.5 mg/dL)
• Unstable severe cardiovascular comorbidities (e.g., unstable angina, heart failure)
• Restenosis after prior CAS or CEA
• Allergy or contraindications to study medications (statins, ASA, losartan, amlodipine)