title: Sex differences in patients with asymptomatic carotid atherosclerotic plaque: in vivo 3.0-T magnetic resonance study.
abstract: OBJECTIVE
  Stroke prevention with carotid endarterectomy in asymptomatic men with carotid stenosis is greater than in women. Men have a higher incidence of stroke <75 years of age. Sex differences in plaque characteristics may help explain this, because several plaque features, including a thin/ruptured fibrous cap, larger lipid-rich/necrotic core, and hemorrhage, are associated with increased risk of stroke. We hypothesize that MRI carotid plaque features will demonstrate sex differences indicative of higher-risk plaque in men.
  
  
  METHODS
  One hundred thirty-one patients (men, 67; women, 64) with >or=50% asymptomatic carotid stenosis on duplex ultrasound were included. Two blinded reviewers interpreted multicontrast MRI. Presence of a thin/ruptured fibrous cap, plaque components (lipid-rich/necrotic core, hemorrhage, and calcification), and percent component volume were documented. The associations between sex and individual plaque characteristics were examined using logistic and linear regression models (2-part models) controlling for demographic characteristics and MR angiographic findings.
  
  
  RESULTS
  Presence of a thin/ruptured fibrous cap (48% versus 17%, adjusted OR=4.41, P<0.01) and lipid-rich/necrotic core (73% versus 50%, adjusted OR=3.66, P=0.01) were more common in men. There was a trend for more highly prevalent hemorrhage (33% versus, 17%, adjusted OR=2.15, P=0.07) in men. Calcification was not significantly associated with sex. Men demonstrated larger volumes of percent lipid-rich/necrotic core (median, 7.7% versus 3.2%, P=0.01), and percent hemorrhage (median, 6.1% versus 1.5%, P<0.01).
  
  
  CONCLUSIONS
  In patients with asymptomatic >or=50% carotid stenosis by duplex ultrasound, men had higher-risk plaque features compared with women after controlling for potential confounders. These findings may help explain sex differences in stroke incidence and prevention.
authors.affiliation: Department of Radiology, Michigan State University, East Lansing, MI 48824-1313, USA.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ota
authors.forename: Mathew J
authors.initials: MJ
authors.lastname: Reeves
authors.forename: David C
authors.initials: DC
authors.lastname: Zhu
authors.forename: Arshad
authors.initials: A
authors.lastname: Majid
authors.forename: Alonso
authors.initials: A
authors.lastname: Collar
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
authors.forename: J Kevin
authors.initials: JK
authors.lastname: DeMarco
mesh_terms: D050197:Atherosclerosis / Q000000981:diagnostic imaging / Q000473:pathology; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D016017:Odds Ratio; D012727:Sex Characteristics; D012737:Sex Factors; D014463:Ultrasonography