Moderate carotid artery stenosis: MR imaging-depicted intraplaque hemorrhage predicts risk of cerebrovascular ischemic events in asymptomatic men.
OBJECTIVE
To investigate the association between magnetic resonance (MR) imaging-depicted intraplaque hemorrhage (IPH) in the carotid artery wall and the risk of future ipsilateral cerebrovascular events in men with asymptomatic moderate carotid stenosis by using a rapid three-dimensional T1-weighted fat-suppressed spoiled gradient-echo sequence.


METHODS
The institutional ethics review board approved this retrospective chart review and waived the requirement for written informed consent. All patients gave informed verbal consent at follow-up telephone interviews. Ninety-one men (mean age, 74.8 years; range, 47-88 years) who attended a vascular clinic between 2003 and 2006, who had asymptomatic carotid stenosis (50%-70% at Doppler ultrasonography), and who had undergone MR imaging for IPH detection were retrospectively identified. Seventy-five men with 98 eligible carotid arteries were included in the study. Patients were followed for a minimum of 1 year (mean follow-up, 24.92 months; range, 12-43 months). Kaplan-Meier survival and univariate Cox regression analyses were conducted to compare future ipsilateral cerebrovascular event rates between carotid arteries with and those without MR-depicted IPH.


RESULTS
Of the 98 carotid arteries included, 36 (36.7%) had MR-depicted IPH. Six cerebrovascular events (two strokes and four transient ischemic attacks) occurred in the carotid arteries with IPH, as compared with no clinical events in the carotid arteries without IPH. Univariate Cox regression analysis confirmed that MR-depicted IPH was associated with an increased risk of cerebrovascular events (hazard ratio, 3.59; 95% confidence interval: 2.48, 4.71; P < .001). MR-depicted IPH negatively predicted outcomes (negative predictive value = 100%).


CONCLUSIONS
In this cohort with asymptomatic moderate carotid stenosis, MR-depicted IPH was associated with future ipsilateral cerebrovascular events. Conversely, patients without MR-depicted IPH remained asymptomatic during follow-up. The absence of IPH at MR imaging, therefore, may be a reassuring marker of plaque stability and of a lower risk of thromboembolism.
Singh
Navneet
N
Department of Diagnostic Imaging, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview St, Toronto, ON, Canada M4N 3M5.
Moody
Alan R
AR
Gladstone
David J
DJ
Leung
General
G
Ravikumar
Radhakrishnan
R
Zhan
James
J
Maggisano
Robert
R
D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000175:diagnosis* / Q000453:epidemiology*; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000453:epidemiology*; D002543:Cerebral Hemorrhage / Q000175:diagnosis* / Q000453:epidemiology*; D015897:Comorbidity; D006801:Humans; D015994:Incidence; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity