Treatment of atherosclerotic intracranial arterial stenosis.

Abstract

David Pelz MD L. Nelson Hopkins MD Elad Levy MD Section Editors: Atherosclerotic stenosis of the major intracranial arteries (intracranial internal carotid artery, middle cerebral artery, vertebral artery, basilar artery) is probably the most common cause of stroke worldwide.1 Intracranial atherosclerosis causes 30% to 50% of strokes in Asia2 and 8% to 10% of strokes in North America.3 This review focuses on the medical and endovascular treatment of atherosclerotic intracranial arterial stenosis. Initially, a retrospective study suggested that warfarin was superior to aspirin for stroke prevention in patients with symptomatic intracranial arterial stenosis.4 This retrospective data combined with a proposed pathophysiological rationale for anticoagulation5 made warfarin a common treatment choice for symptomatic intracranial stenosis.6 However, the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial showed that aspirin was safer and as effective as warfarin for stroke prevention in patients with symptomatic intracranial stenosis. WASID was stopped early after a mean follow-up of 1.8 years because of higher rates of death and major hemorrhage in the warfarin arm. The primary end point of ischemic stroke, brain hemorrhage or vascular death, occurred in 22.1% of patients assigned aspirin and 21.8% of those in the warfarin group.7 The rates of myocardial infarction or sudden death were also higher in the warfarin arm. Certain high-risk subgroups of patients with intracranial stenosis were previously thought to benefit from anticoagulation, such as those with severe stenosis,4 vertebrobasilar disease,4 and those who have failed antithrombotic therapy.8 In WASID, however, patients with severe stenosis9 or those previously on antithrombotic therapy9,10 did not benefit from warfarin. Patients with basilar artery stenosis in WASID did appear to have a lower rate of the primary end point on warfarin, but there was no difference in the rate of stroke in the …