Stroke risk in patients with carotid stenosis.
In 242 neurologically symptomless patients with at least one non-occlusive carotid stenosis on ultrasonography (continuous wave doppler and echotomography-B mode imaging) 171 carotids showed 0-50% stenosis, 150 showed 50-75% stenosis, and 78 showed more than 75% stenosis. The mean follow-up was 29.4 months, with stroke and death as end points. Of the 56 deaths 2 were causally linked to a stroke (crude annual mortality index 9.57%). Of the 10 strokes 7 were judged to be infarctions in carotid territory. 7 out of 20 patients with transient ischaemic attacks (TIA) had ischaemic symptoms definitely related to carotid territory. The crude annual indices of specific stroke or TIA were 0.45% for nonstenotic carotid, 0.23% for 0-50% stenosis, 2.48% for 50-75% stenosis, and 1.71% for 75-99% stenosis. Stenoses of greater than 50% were associated with more ischaemic events than were lesser degrees of narrowing (p less than 0.01).
D000368:Aged; D002340:Carotid Artery Diseases / Q000150:complications*; D002561:Cerebrovascular Disorders / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality; D003251:Constriction, Pathologic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002546:Ischemic Attack, Transient / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012306:Risk