title: Atherosclerotic plaque in the left carotid artery is more vulnerable than in the right.
abstract: OBJECTIVE
  Ischemic stroke is more often diagnosed in the left hemisphere than in the right. It is unknown whether this asymmetrical prevalence relates to differences in carotid atherosclerosis. We compared atherosclerotic plaque prevalence, severity, and composition between left and right carotid arteries.
  
  
  METHODS
  In a population-based cohort, carotid MRI scanning was performed in 1414 stroke-free participants (≥45 years). Using a multisequence MRI protocol, we assessed the prevalence, stenosis, and thickness of the plaque and its predominant component (ie, lipid core, intraplaque hemorrhage, calcification, or fibrous tissue in each carotid artery). Differences between left and right side were tested using paired t tests, McNemar test and Generalized Estimating Equation analyses.
  
  
  RESULTS
  The majority (85%) of the participants had bilateral carotid plaques. Unilateral plaques were twice more prevalent on the left than on the right side (67% versus 33%; P<0.001). Plaque thickness was also greater on the left (3.1±1.2 versus 2.9±1.3 mm; P<0.001); degree of stenosis did not differ. Intraplaque hemorrhage and fibrous tissue were more prevalent on the left (9.1 versus 5.9%; P<0.001 and 45.0 versus 38.5%; P<0.001), whereas calcification occurred more often on the right (37.4 versus 31.6% at the left; P<0.001). Lipid was equally distributed.
  
  
  CONCLUSIONS
  Carotid atherosclerotic plaque size and composition are not symmetrically distributed. Predominance of intraplaque hemorrhage in left-sided carotid plaques suggests a greater vulnerability as opposed to right-sided plaques, which are more calcified and therefore considered more stable.
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Mariana
authors.initials: M
authors.lastname: Selwaness
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Quirijn
authors.initials: Q
authors.lastname: van den Bouwhuijsen
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Robbert S
authors.initials: RS
authors.lastname: van Onkelen
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: Hofman
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Oscar H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Jolanda J
authors.initials: JJ
authors.lastname: Wentzel
authors.affiliation: From the Departments of Epidemiology (M.S., Q.v.d.B., R.S.v.O., A.H., O.H.F., M.V.), Radiology (Q.v.d.B., A.v.d.L., M.V.), and Cardiology (J.J.W.), Erasmus MC, Rotterdam, The Netherlands. m.vernooij@erasmusmc.nl.
authors.forename: Meike
authors.initials: M
authors.lastname: Vernooij
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000453:epidemiology; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors
keywords: atherosclerosis; carotid arteries; magnetic resonance imaging