Consensus conference on intracranial atherosclerotic disease: rationale, methodology, and results

The consensus conference on intracranial atherosclerotic disease (ICAD) identifies principles of management, and research priorities in various aspects upon which leading experts can agree (using "Delphi" method). ICAD is more prevalent in Asian, Hispanic, and African-American populations. Patients who have had a stroke or transient ischemic attack (TIA) attributed to stenosis (50-99%) of a major intracranial artery face a 12-14% risk of subsequent stroke during the 2-year period after the initial ischemic event, despite treatment with antithrombotic medications. The annual risk of subsequent stroke may exceed 20% in high-risk groups. The medical treatment of patients with symptomatic ICAD is directed toward: 1. Prevention of intraluminal thrombo-embolism, 2. plaque stabilization and regression, and 3. management of atherogenic risk factors. In patients with ICAD, short-term and long-term anticoagulation (compared with aspirin) have not shown to be beneficial. The current guidelines recommend that aspirin monotherapy, the combination of aspirin and extended release dipyridamole, and clopidogrel monotherapy (rather than oral anticoagulants) are all acceptable options in patients with non-cardioembolic ischemic stroke and TIA. Overall, the subgroup analysis from randomized trials provides evidence about benefit of aggressive atherogenic risk factor management among patients with ICAD. Intracranial angioplasty with or without stent placement has evolved as a therapeutic option for patients with symptomatic ICAD, particularly those with high-grade stenosis with recurrent ischemic symptoms and/or medication failure. A matched comparison between medical-treated patients in the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) study and stent-treated patients in the National Institutes of Health intracranial stent registry concluded that stent placement may offer benefit in patients with 70-99% stenosis. The 5-year, multicenter, prospective, randomized Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis study supported by the National Institutes of Health is currently comparing stent placement with intense medical management with intense medical management alone in patients with high-grade symptomatic intracranial stenosis. The proceedings of the consensus conference provide a template for standardizing management of patients with ICAD and determining research priorities.