Sheri L. Koshman, BScPharm, ACPR, PharmD, Assistant Professor of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB.
Glen J. Pearson, BSc, BScPhm, PharmD, FCSHP, Associate Professor of Medicine; Division of Cardiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB.

Antiplatelet agents are the cornerstone of secondary prevention for patients who present with an ischemic stroke or transient ischemic attack (TIA). At present, monotherapy with acetylsalicylic acid (ASA) or clopidogrel or the combination regimen of ASA plus extended-release dipyridamole are recommended as first-line options in the stroke prevention guidelines. The combination of ASA and clopidogrel is not routinely recommended for secondary stroke prevention, since it has been shown to offer no therapeutic advantage and an increased risk of bleeding. The clear answer as to whether one or two antiplatelet agents are better for the secondary prevention of ischemic stroke events in older adults depends upon the combination of agents, as well as the monotherapy comparator.
Key words: stroke prevention, clopidogrel, acetylsalicylic acid, dipyridamole, antiplatelet agents.

Nikolai Steffenhagen MD, Calgary Stroke Program, University of Calgary, Calgary, AB.
Michael D. Hill, MD, MSc, FRCPC, Calgary Stroke Program, University of Calgary, Calgary, AB.

The majority of strokes occur among the older adult population. Typically, ischemic stroke can be classified by mechanism, and this is the most practical way to think about stroke since it has a direct bearing on the approach to prevention. It is not enough to simply consider that a past stroke implies a need for antiplatelet therapy or anticoagulant therapy without consideration of cause. In this article, we discuss the use of preventive strategies within the context of antithrombotics and according to stroke mechanism.
Key Words: stroke prevention, geriatric, octogenerian, vascular risk factors, carotid stenosis, atrial fibrillation.

Ashfaq Shuaib, MD, FRCPC, FAHA, Professor of Neurology and Medicine, Director, Division of Neurology, University of Alberta, Edmonton, AB.

Stroke is a common neurological problem in older adults. Most patients have identifiable risk factors. Identification and treatment of such conditions can result in a significant reduction in recurrence. In addition, patients with an acute ischemic stroke require lifelong treatment with antithrombotic agents. For the vast majority of patients, acetylsalicylic acid (ASA) in a dose of 50-325mg per day is sufficient. In patients who are unable to tolerate ASA (75mg per day) clopidogrel may be an alternative. Both clopidogrel and ASA/ extended-release dipyridamole are useful alternative medications, especially in patients with recurrent symptoms. In 20% of patients the ischemic stroke may be secondary to cardioembolic causes (atrial fibrillation is the most frequent cardiac cause). In such subjects, treatment with warfarin with INRs in the range of two to three may provide better reduction in recurrence than ASA.

Key words: stroke, stroke prevention, antithrombotic agents, cardioembolic.