| Antithrombotic therapies are effective for primary and secondary prevention of ischemic stroke. Atrial fibrillation is the most common cause of cardioembolic stroke. Oral anticoagulants (e.g. warfarin) are more effective than aspirin for prevention of ischemic stroke in patients with atrial fibrillation, but are associated with a greater risk of major bleeding. In acute ischemic stroke, parenteral anticoagulants (e.g. heparins) are not more effective than aspirin for prevention of recurrent stroke in patients with atrial fibrillation.;Employing a variety of study designs, this thesis addresses the following areas: (1) the association between pre-admission antithrombotic therapy and stroke severity in patients with atrial fibrillation, (2) the effectiveness and safety of low-molecular-weight heparins for prevention of ischemic stroke in patients with acute stroke and in patients requiring temporary interruption of warfarin, (3) the comparative frequency of recurrent ischemic stroke and myocardial infarction after ischemic stroke, and (4) a protocol for a randomized controlled trial to determine whether warfarin therapy is superior to antiplatelet therapy for prevention of major vascular events following cryptogenic ischemic stroke of presumed cardioembolic origin. The content provides novel information that adds to our understanding of the effectiveness and safety of antithombotic therapy for primary and secondary prevention of cardioembolic ischemic stroke. |
