PREVAIL: PREvention of VTE After Acute Ischemic Stroke With LMWH Enoxaparin ( - VTE: Venous Thromboembolism - LMWH: Low Molecular Weight Heparin)

Primary objective: * To demonstrate superiority of enoxaparin 40 mg sc qd in the prevention of VTE compared to UFH (unfractionated heparin) 5000 U sc q12 hours given for 10 ± 4 days following acute ischemic stroke. Secondary objectives: * To compare the incidence of VTE between the 2 treatment groups at 30, 60, and 90 days from the time of randomization * To compare neurologic outcomes between the 2 treatment groups, including incidence of stroke recurrence, rate of stroke progression, and patient functional status, during the 10 ± 4 days of treatment, and after 30, 60, and 90 days from the time of randomization * To evaluate the safety of using enoxaparin compared to UFH for VTE prevention in patients following acute ischemic stroke