Risk factors associated with severity and location of intracranial arterial stenosis.

BACKGROUND AND PURPOSE We sought to determine the vascular risk factors and demographic features associated with the severity and location of intracranial stenosis. METHODS Data on patients enrolled in the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial were used for the analyses. Demographic features and vascular risk factors were compared in patients with moderate stenosis (n=336) versus severe stenosis (n=225) and according to the location of intracranial stenosis (middle cerebral, internal carotid, basilar, or vertebral artery). RESULTS History of a lipid disorder (77% in severe vs 67% in moderate, P=0.01), metabolic syndrome (63% in severe vs 53% in moderate, P=0.05), and diabetes (43% in severe vs 35% in moderate, P=0.04) were more common in patients with severe intracranial stenosis by univariate analyses. A history of a lipid disorder was independently associated with severe stenosis (odds ratio=1.62; 95% CI, 1.09 to 2.42; P=0.02). The distribution of stenosis location differed among age groups (P=0.0015), sexes (P=0.0001), races (P=0.0243), qualifying events (P=0.0156), diabetes (P=0.0030), coronary artery disease (P=0.0030), and hyperlipidemia (P=0.054). Patients with basilar artery stenoses were older and more likely to have hyperlipidemia. Patients with middle cerebral artery stenoses were more likely to be women and black. Patients with internal carotid artery stenoses were more likely to have diabetes. Patients with vertebral artery stenoses were more likely to have coronary artery disease. CONCLUSIONS History of a lipid disorder had the strongest association with severity of intracranial stenosis and should be the target of prevention therapies. Different locations of intracranial stenoses are associated with different vascular risk factors and demographic features, suggesting that there may be a difference in the underlying pathophysiology of stenoses among the intracranial arteries.