Published online before print January 3, 2008, doi: 10.1161/STROKEAHA.107.498634
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(Stroke. 2008;39:329.)
© 2008 American Heart Association, Inc.
Original Contributions |
Risk Factor Associations With the Presence of a Lipid Core in Carotid Plaque of Asymptomatic Individuals Using High-Resolution MRI
The Multi-Ethnic Study of Atherosclerosis (MESA)
From The Russell H. Morgan Department of Radiology and Radiological Sciences (B.A.W., D.A.B.) and the Department of Pathology (S.L.), The Johns Hopkins University School of Medicine, Baltimore, Md; the Department of Epidemiology (A.R.S.), The Johns Hopkins Bloomberg School of Public Health, Baltimore, Md; the Department of Radiological Sciences (A.S.G.), University of California at Los Angeles, David Geffen School of Medicine, Los Angeles, Calif; the Departments of Medicine and Pathology (M.C.), University of Vermont, Burlington, Vt; the Division of Epidemiology (A.R.F.), School of Public Health, University of Minnesota, Minneapolis, Minn; the Division of Prevention and Population Sciences (D.E.B.), National Heart, Lung, and Blood Institute, Bethesda, Md; the Department of Biostatistics (R.A.K.), School of Public Health and Community Medicine, University of Washington, Seattle, Wash; and the Department of Radiology (S.S.), University of California at San Diego Medical Center, San Diego, Calif.
Correspondence to Bruce A. Wasserman, MD, The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, Phipps B-100, 600 N. Wolfe Street, Baltimore, MD 21287. E-mail bwasser{at}jhmi.edu
Background and Purpose— Atheroma vulnerability to rupture is increased in the presence of a large lipid core. Factors associated with a lipid core in the general population have not been studied.
Methods— The Multi-Ethnic Study of Atherosclerosis (MESA) is a multicenter cohort study of individuals free of clinical cardiovascular disease designed to include a high proportion of ethnic minorities. We selected MESA participants from the top 15th percentile of maximum carotid intima media thickness by ultrasound and acquired high-resolution black blood MRI images through their carotid plaque before and after the intravenous administration of gadodiamide (0.1 mmol/kg). Lumen and outer wall contours were defined using semiautomated analysis software. We analyzed only plaques with a maximum thickness 
1.5 mm by MRI (n=214) and assessed cross-sectional risk factor associations with lipid core presence by multivariable logistic regression.
Results— A lipid core was present in 151 (71%) of the plaques. After controlling for age, ethnicity, sex, maximum arterial wall thickness, hypertension, cigarette smoking, diabetes, and C-reactive protein, compared with participants in the lowest tertile of total plasma cholesterol, the ORs of having a lipid core for participants in the middle and highest tertiles were 2.76 (95% CI: 1.01 to 7.51) and 4.63 (95% CI: 1.56 to 13.75), respectively. None of the other risk factors was associated with lipid core.
Conclusions— In persons with thickened carotid walls, plasma total cholesterol, but not other established coronary heart disease risk factors, is strongly associated with lipid core presence by MRI. High total cholesterol may be associated with rupture proneness of atherosclerotic lesions in the general population.
Key Words: atherosclerosis • carotid artery • cholesterol • lipid core • magnetic resonance • MRI • risk factors • stroke