STROKE IS A MAJOR CAUSE OF MORBIDITY and mortality in an aging population. The current understanding of the pathophysiology of atherosclerotic diseases, the most common cause of stroke, and the evidence for existing therapeutic interventions for the prevention of stroke are presented. Specifically, we review the evidence for antiplatelet agents, anticoagulants, antihypertensive medications, lipidlowering agents and carotid endarterectomy for stroke prevention. primary preventive measure, antiplatelet agents do not reduce the risk of ischemic stroke among patients without vascular disease. They are associated with an increased risk of intracranial hemorrhage (odds ratio [OR] 1.35, 95% confidence interval [CI] 0.88-2.10) 23 and major noncerebral hemorrhage (OR 1.73, 95% CI 1.14-2.63 ). 24 The benefits of ASA in the secondary prevention of stroke have been well documented in the period immediately after a stroke 25 (Table 1). Long-term antiplatelet treatment after stroke shows an even more impressive reduction of 25 nonfatal strokes and 36 serious vascular events per 1000 treated over a 29-month follow-up period. 25 There appears to be no difference in efficacy between low (50 mg) and higher doses (up to 1500 mg) of ASA. 29,30 The combination of dipyridamole and ASA has been shown to reduce the relative risk of recurrent stroke compared with ASA alone 26 (Table 1). Dipyridamole inhibits platelet aggregation by increasing levels of cyclic adenosine monophosphate and cyclic guanosine monophosphate. The limiting factor in the use of the ASAdipyridamole combination is the latter's potential effects on coronary perfusion. Dipyridamole can cause coronary vasodilation, which results in increased blood flow to nonstenosed coronary arteries. The result is that myocardial ischemia may be provoked during exercise. As such, the current American College of Cardiology/American Heart Association guidelines recommend that dipyridamole not be used in patients with chronic stable angina. 31 However, this recommendation was based on shortacting dipyridamole, which also reduced myocardial ischemia in a similar number of patients in the study quoted by these guidelines. 32 With the use of sustained-release dipyridamole, no increase in cardiac events was observed in subjects with prior coronary artery disease. 33 Thienopyridines block adenosine-diphosphate-mediated platelet aggregation. Ticlopidine was the first of this class of drug to be studied for stroke prevention. One clinical trial demonstrated that patients treated with ticlopidine had similar rates of stroke as those treated with ASA 28 (Table 1). However, serious granulocytopenia associated with ticlo- Leukocytes localize in the earliest atherosclerotic lesions, binding to vascular cell adhesion molecules (VCAM-1) on the vascular endothelium and migrating into the intima. This initiates and perpetuates a local inflammatory response. Monocytes mature into lipid-scavenging macrophages and subsequently foam cells. T-lymphocytes express inflammatory cytokines, which cont...