Abstract 4145507: Impact of Angiotensin-I-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers on Carotid Plaque Composition Assessed By MRI

Background: Carotid artery stenosis is a well-established risk factor for ischemic stroke, contributing to 10-20% of strokes or transient ischemic attacks. Currently, MRI is the gold standard in carotid plaque imaging due to its high resolution and high sensitivity for identifying intraplaque hemorrhage, ulceration, lipid-rich necrotic core, and inflammation. The purpose of the study is to determine the effects of Angiotensin-I-converting enzyme inhibitors(ACEIs) and Angiotensin receptor blockers (ARBs) on carotid plaque characteristics. Methods: Before elective carotid revascularization 30 patients (mean age 72±8 years; 16 males, 14 females) underwent 3-T MRI. After localization of the carotid bifurcation using phase contrast imaging, Time-of-Flight, 3D T1 weighting, transverse T1 and T2 weightings and proton density sequences were acquired. The different plaque components: lipid core, intraplaque hemorrhage, calcification and the characterization of the fibrous cap were assessed. 16 patients were on ACEIs or ARBs. Results: MRI demonstrated that although 25% of patients who were on ACEIs or ARBs had lipid-rich necrotic core, 71% of patients who were not on ACEIs or ARBs had lipid-rich necrotic core. While 9 (90%) males who were not on ACEIs or ARBs had lipid rich necrotic core, 1 (25%) female who was not on ACEIs or ARBs had lipid rich necrotic core, p=0.015. There was no gender difference for lipid rich necrotic core in patients who were on ACEIs or ARB. Conclusion: This study demonstrated that patients receiving ACEIs or ARBs had less lipid rich necrotic core in the carotid plaques compared to patients not receiving ACEIs or ARBs. Additionally, patients with lipid-rich necrotic core who were not on ACEIs or ARBs were mostly males.