Abstract 15452: Carotid Magnetic Resonance Imaging and Ultrasound Intima-Media Thickness for the Prediction of Cardiovascular Events: the Multi-Ethnic Study of Atherosclerosis
Introduction: Carotid MRI has been shown to accurately depict wall thickness and plaque components such as lipid core. Whereas carotid IMT by ultrasound has been validated to predict cardiovascular events, the use of carotid MRI for prediction of cardiovascular events has not previously been shown in a population-based study.
Methods: Carotid MRI was performed as part of the Multi-Ethnic Study of Atherosclerosis (MESA) in adults between the ages 45 and 84 years free of clinical cardiovascular disease at enrollment. A group of 847 participants underwent high-resolution black blood MRI with semi-automated vessel contouring to assess wall area, thickness, signal intensity and the presence of plaque components. These participants were then prospectively followed for the occurrence of cardiovascular events defined as a composite endpoint including MI, resuscitated cardiac arrest, angina, heart failure, stroke, TIA, peripheral vascular disease and cardiovascular death.
Results: Over a follow-up period of 4.6 +/− 1.0 years (mean +/− S.D.), 63 of the 847 MRI participants experienced a cardiovascular event. After adjusting for age, gender, and traditional cardiovascular risk factors, the MRI defined outer-wall-to-lumen-area ratio remained a significant predictor of cardiovascular events with a hazard ratio (95% confidence limits) of 1.26 (1.10, 1.45) per S.D. increase in wall-lumen ratio (p = 0.001). Carotid IMT demonstrated a comparable hazard of 1.23 (1.00, 1.52) per S.D. increase in maximal wall thickness (p = 0.05). Receiver operating curve analysis demonstrates a shift in the c-statistic from 0.762 for the base covariates alone, to 0.773 for base plus IMT and to 0.771 for base plus MRI.
Conclusions: In the MESA study, carotid MRI and ultrasound IMT were both significant predictors of cardiovascular events.
- © 2011 by American Heart Association, Inc.