Abstract 16675: Intraplaque Hemorrhage-induced Atherosclerotic Plaque Progression as the Bridge Between Intact and Ulcerated Plaques: An Imaging-based Natural History Study

Introduction: Previous studies have associated intraplaque hemorrhage (IPH) with future ischemic events, of which the mechanisms are less understood. Hypothesis: Understanding morphological features and progression behaviors of plaques with and without IPH would allow us to define the role of IPH in the natural history of atherosclerosis. Methods: In an ongoing study, asymptomatic subjects with 16-79% stenosis on ultrasound underwent 3-dimensional carotid MRI. Those with carotid plaque(s) on MRI were recruited and a follow-up scan was performed 1-year later using the same protocol. Individual plaques (maximum thicknessu003e1.5 mm) within scan coverage were identified in bilateral carotids, of which morphological data were collected at baseline and plaque progression was determined by comparing both scans while blinded to the time sequence. Results: Twenty-nine subjects have completed the study. A total of 64 de novo plaques were identified, of which 15 (23.4%) demonstrated IPH. Plaques with IPH are more likel...