Abstract 14835: Carotid Artery Plaque Burden and Characteristics and Subsequent Risk of Incident Cardiovascular Events: The Atherosclerosis Risk in Communities (ARIC) Carotid Magnetic Resonance Imaging Study
Objective: Magnetic Resonance Imaging (MRI) of the carotid arteries measures atherosclerotic plaque burden and plaque composition. Studies have shown that the burden of atherosclerosis in carotid arteries predicts cardiovascular disease (CVD) outcomes in other vascular beds including the coronary arteries. It is not known whether plaque characteristics seen on carotid MRI are associated with incident CVD events independent of plaque burden.
Methods: We evaluated the carotid artery MRI in 1,706 ARIC Study participants in 2004-2005. Carotid vessel wall thickness, vessel wall area, and normalized wall index (NWI) (measures of plaque burden) and lipid core presence and fibrous cap thickness (measures of plaque characteristics) were evaluated. We performed Cox proportional hazards model to study the independent association between measures of carotid plaque burden or plaque characteristics (per standard deviation increase in continuous MRI variables and presence of lipid core) and incident CVD events (composite of coronary heart disease or ischemic strokes).
Results (Table): Final analyses included 1,471 participants after excluding 235 with prevalent CVD. At a mean follow-up of 3.7 years, 102 participants suffered an incident CVD event. Among measures of plaque burden, NWI showed a borderline significant association with incident CVD in the fully adjusted model. Among plaque characteristics, lipid core presence (seen in 573 participants) and mean minimum fibrous cap thickness were independently associated with incident CVD in adjusted models that also included measures of carotid plaque burden.
Conclusion: In this large prospective study with rigorous quality control, MRI measures of carotid plaque burden and plaque characteristics were independently associated with incident CVD events. Carotid MRI derived measures of both plaque burden and plaque characteristics may be useful imaging surrogates to identify those at higher risk of future CVD events.
- © 2013 by American Heart Association, Inc.