Abstract 2839: The Association between Carotid Plaque Characteristics and Cardiovascular Events: Prospective Prediction by Magnetic Resonance Imaging
Background: We previously demonstrated that three-dimensional inversion-recovery T1-weighted imaging (MPRAGE) could successfully identify complicated atheromas, which are associated with ipsilateral ischemic cerebral symptoms, as high-intensity signals within the carotid arterial wall. We hypothesized that these carotid plaques may predict subsequent cardiovascular events in patients with ischemic heart disease.
Methods: We examined 186 patients with chronic ischemic heart disease using plaque imaging by MPRAGE on a clinical MRI system. Patients were divided into two groups according to the presence or absence of high-intensity MPRAGE signals. High-intensity MPRAGE signals were defined by intensities 200% higher than those of the adjacent muscles. We also measured cholesterol profiles, high-sensitivity C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), and interleukin-6 (IL-6) as markers for cardiovascular risk. The endpoint of this study was major adverse cardiovascular events (sudden death, heart failure, acute myocardial infarction, urgent revascularization, or hospital admission for unstable angina).
Results: The incidence of acute myocardial infarction or hospital admission for unstable angina during a three-year follow-up period was 27% (16/59) in patients with high-intensity MPRAGE signals and 5% (7/127) in patients without high-intensity MPRAGE signals (RR 3.1, 95%CI 1.5–6.3). Survival without myocardial infarction, urgent revascularization, or hospital admission for unstable angina was significantly lower in patients with low-signal MPRAGE findings than in patients with high-signal MPRAGE findings (log-rank p<0.001). Logistic regression analysis identified CRP levels and high-intensity signals on MPRAGE images as independent predictors of event-free survival (RR 1.7, 95%CI 1.3–3.0, p<0.01, and RR 2.4, 95%CI 1.5–4.5, p<0.001, respectively).
Conclusion: High-intensity MPRAGE signals of the carotid artery may potentially identify patients with vulnerable coronary artery plaques in patients with ischemic heart disease.