Abstract 126: Are Carotid Plaques With Intraplaque Hemorrhage Different in Plaque Size, Distribution and Shear Stress?
Introduction: Intraplaque hemorrhage (IPH) is associated with risk at ischemic stroke. In addition, plaques that contain IPH show accelerated plaque growth, which might affect the local shear stress (SS) distribution over the plaque. Blood flow induced SS is known to be involved in the development and destabilization of atherosclerotic plaques. It is unknown whether the SS distribution over plaques with IPH differs from plaques without IPH and whether SS is involved in plaque progression/destabilization of plaques with IPH. We compared the plaque size, distribution and SS over plaques with and without IPH in symptomatic patients.
Methods: 38 patients with a recent (<3 months) TIA or minor stroke of the PARISK (Plaque At Risk) study and with carotid artery stenosis 2 mm were selected for analysis. To calculate local SS, the lumen contours were used in FIDAP, a CFD software package. The mean and maximum shear stress at the plaque was normalized to the average shear stress in the common carotid artery (NSSmean, NSSmax). The NSSmean and NSSmax were compared for plaques with and without IPH.
Results: In 75 carotid arteries plaque was observed (99%). The 29 plaques (39%) that contained IPH were longer (17±5 vs 11±6 mm, p<0.05) and located more proximal in the carotid bulb than plaques without IPH. Symptomatic vessels contained more often IPH (76%) than plaques from asymptomatic arteries (23%). Plaques that contained IPH in symptomatic arteries were not different in length (17±4 mm) compared to plaques with IPH in asymptomatic arteries (16±5 mm). In 18 symptomatic vessels the SS could be calculated. The NSSmean did not differ for plaques with or without IPH (0.98±0.35 vs 0.75±0.40), whereas the NSSmax for plaques with IPH was 2x higher than for plaques without IPH (1.32 ±0.35 vs 3.06±1.45, p<0.05).
Conclusion: Carotid plaques that contain IPH are longer, located more proximal in the carotid bulb and exposed to higher SS than plaques without IPH. IPH determines the plaque length, which was not influenced by the presence or absence of symptoms. Since IPH is associated with stroke risk, the higher SS and larger plaque size potentially contribute to this increased stroke risk.
Author Disclosures: Z.A.M. Kassar: None. L. Speelman: None. A. van Dijk: None. M. Selwaness: None. M. Cibis: None. F.J.H. Gijsen: None. A.F.W. Van der steen: None. A. van der Lugt: None. J.J. Wentzel: None.
- © 2014 by American Heart Association, Inc.