Abstract WP125: Comparison Of Carotid Intraplaque Hemorrhage With Other Markers Of Plaque Vulnerability.

Abstract

Background: MR detected carotid intraplaque hemorrhage (IPH) has been associated with acute ischemic events. Other markers of plaque vulnerability can also be imaged by MRI/MRA and include >70% carotid stenosis, plaque ulceration, and intraluminal thrombus. Atherosclerosis is a systemic disease, and many of these markers are found bilaterally in patients. Objective: To determine the relative risk acute ischemic events with carotid IPH compared to other markers of plaque vulnerability, and to determine whether IPH is associated with these markers and contralateral IPH. Methods: Over 2 years, 159 patients with suspected acute stroke were evaluated with brain DTI and MRA neck workup. Carotid MRA included lumen evaluation as well as carotid plaque imaging with the MPRAGE sequence. This provided 318 carotid artery and ipsilateral brain images for analysis. 48 arteries were excluded due to extracarotid sources of brain ischemia and 4 were excluded due to carotid occlusion. 266 arteries were eligible for data analysis. Results: Acute territorial ischemic events were associated with carotid IPH, >70% stenosis, ulceration and intraluminal thrombus (relative risk=6.4 (4.3-8.7), 4.4 (2.8-5.9), 3.8 (2.4-5.6), and 5.7 (3.6-5.7) respectively, p<0.001). Within the same carotid plaque, IPH was associated with ulceration and >70% stenosis (relative risk=7.8 (4.4-13.1) and 6.0 (2.6-13.8) respectively, p<0.001). There was a trend toward association with intraluminal thrombus, but this did not reach significance (relative risk=3.4 (0.9-12.4), p=0.056). Carotid IPH also increased the relative risk of contralateral carotid IPH (relative risk=6.3, (3.4-10.9), p<0.001). Conclusions: Carotid IPH is associated with acute stroke, with a relative risk on par with other markers of plaque vulnerability. Carotid IPH is highly associated with ulceration or >70% stenosis. Carotid IPH is also associated with contralateral IPH, suggesting that systemic factors result in plaque hemorrhage elsewhere in the body.