Stroke: Highlights of Selected Articles

In this study, the authors sought to determine the epidemiology of intracranial atherosclerotic stenosis (ICAS) in the United States. To this end, they selected 1765 participants from the community-based cohort of the Atherosclerosis Risk in Communities (ARIC) study who underwent good quality high resolution 3-tesla magnetic resonance angiography from 2011 to 2013. They graded ICAS according to the severity of stenosis (none, <50%, 50%–69%, 70%–99%, and complete arterial occlusion). Magnetic resonance imaging included highresolution sequences to identify plaque and measure the intracranial vessel wall, lumen area, and plaque. Magnetic resonance images were analyzed by blinded certified readers. Forty-one percent of the participants were men, 70% were white, 29% were black, and 3% had previous stroke. The prevalence of ICAS in at least 1 artery was 31%, and ICAS was most commonly seen in the internal carotid artery, although more severe stenosis was seen in the posterior cerebral artery. Multiple ICAS lesions were frequent and seen in 52%. The prevalence of ICAS ≥50% was 9% (95% confidence interval, 8%–10%) and ICAS ≥70% was 5% (95% confidence interval, 4%–5%). The authors estimated that the prevalence of ICAS ≥50% for the United States population aged 65 to 90 years was 8% for whites and 12% for blacks. In this study, odds of any-ICAS were higher for greater age, black race (compared with whites), greater systolic blood pressure, greater low-density lipoprotein, and lesser high-density lipoprotein. After excluding lowdensity lipoprotein and high-density lipoprotein, use of cholesterollowering medication was significantly associated with lower odds of any-ICAS (odds ratio, 0.69; 95% confidence interval, 0.52–0.92). Surprisingly, smoking was not associated with ICAS in this study. The authors noted that the prevalence of ICAS in their cohort was much higher than previously reported, possibly because of the use of highresolution magnetic resonance angiography and the older age of participants. On the basis of these data, the authors postulate that the use of statins could be of benefit for prevention of ICAS and stroke in the higher risk population in the United States. See p 1187.