RT Journal Article
SR Electronic
T1 Early risk of stroke after a transient ischemic attack in patients with internal carotid artery disease
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP 1105
OP 1109
DO 10.1503/cmaj.1030460
VO 170
IS 7
A1 Michael Eliasziw
A1 James Kennedy
A1 Michael D. Hill
A1 Alastair M. Buchan
A1 Henry J.M. Barnett
A1 for The North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group
YR 2004
UL http://www.cmaj.ca/content/170/7/1105.abstract
AB Background: Transient ischemic attacks (TIAs) often herald a stroke, but little is known about the acute natural history of TIAs. Our objective was to quantify the early risk of stroke after a TIA in patients with internal carotid artery disease.Methods: Using patient data from the medical arm of the North American Symptomatic Carotid Endarterectomy Trial, we calculated the risk of ipsilateral stroke in the territory of the symptomatic internal carotid artery within 2 and 90 days after a first-recorded hemispheric TIA. We also studied similar outcomes among patients in the trial who had a first-recorded completed hemispheric stroke.Results: For patients with a first-recorded hemispheric TIA (n = 603), the 90-day risk of ipsilateral stroke was 20.1% (95% confidence interval [CI] 17.0%–23.2%), higher than the 2.3% risk (95% CI 1.0%–3.6%) for patients with a hemispheric stroke (n = 526). The 2-day risks were 5.5% and 0.0%, respectively. Patients with more severe stenosis of the internal carotid artery (> 70%) appeared to be at no greater risk of stroke than patients with lesser degrees of stenosis (adjusted hazard ratio 1.1, 95% CI 0.7–1.7). Infarct on brain imaging (adjusted hazard ratio 2.1, 95% CI 1.5–3.0) and the presence of intracranial major-artery disease (adjusted hazard ratio 1.9, 95% CI 1.3-2.7) doubled the early risk of stroke in patients with a hemispheric TIA.Interpretation: Patients who had a hemispheric TIA related to internal carotid artery disease had a high risk of stroke in the first few days after the TIA. Early risk of stroke was not affected by the degree of internal carotid artery stenosis.