Inclusion Criteria- Age at least 18 years.
- Presence of symptoms of an ischemic stroke with a baseline National Institutes of Health Stroke Scale (NIHSS) scale of one up to 20 or due to an ipsilateral atherosclerotic >50% stenosis of the extracranial internal carotid artery (ICA) as shown by ultrasonography.
- Latency between the onset of stroke symptoms and intended administration of the study drugs is not more than 24 hours.
- Latency between the intended administration of the study drugs and intended carotid endarterectomy is at least three days.
Exclusion Criteria- Documented peptic ulcer disease within the preceding 30 days.
- Septicemia or severe localized infection.
- Severe illness (active cancer or significant liver or renal disease) or disability.
- Alcohol or illicit drug abuse.
- Need for chronic anticoagulant therapy (e.g. atrial fibrillation, deep venous thrombosis).
- Need for long-term daily nonsteroidal antiinflammatory drugs.
- Contraindications for platelet therapy such as severe bleeding disorder within the past three months prior to randomization (coagulopathy, platelet disorder including history of heparin-induced thrombopenia, hemorrhage) or significant retinopathy with hemorrhages and exudates.
- Hypersensitivity to abciximab, murine monoclonal antibodies or aspirin.
- Any preexisting intracranial neurological disease such as tumor or multiple sclerosis.
- Intracranial or intraspinal operation or trauma or lumbar puncture within the last 2 months.
- Cardiac lesions likely to cause cardioembolism.
- Suspicion of or established non-atherosclerotic carotid artery disease such as dissection or vasculitis (Takayasu disease, giant cell arteritis, significant collagen vascular disease, systemic necrotizing vasculitis, granulomatous angiitis of the nervous system).
- Participation in another acute stroke trial investigating drugs other than abciximab.
- Treatment for the present stroke with tissue plasminogen activator, urokinase or ancrod.
- ICH, aneurysm, vascular malformation or arteriovenous fistula or sinovenous thrombosis of the brain.
- Brain infarct involving the whole territory of the middle cerebral artery (MCA).
- Stupor or coma.
- Uncontrolled hypertension (systolic pressure >200 mmHg and/or diastolic pressure >110 mmHg).
- No informed consent.
- Contraindication to undergo magnetic resonance (MR) imaging (eg pacemaker).