Abstract WP136: Enhanced Carotid Plaque on Contrast-enhanced Ultrasound is Asociated with Plaque Instability and Symptomatic Patients

Abstract

Background: Presence of neovascularization in plaque was reported as a reliable maker of plaque vulnerability. Contrast-enhanced ultrasound (CEUS) can demonstrate the presence of intraplaque neovascularization. The aim of the present study was to investigate the neurological symptom and histopathologic findings of enhanced carotid plaque using CEUS. Methods: We studied consecutive 30 patients (27 men, age 68.2 ± 7.6 years) who underwent carotid endarterectomy. Enhanced plaque (enhanced group) was classified into two subgroups: a spotty pattern as moving bright spots within plaque (spotty subgroup, Figure A); and a linear pattern, where enhanced lesions appeared as a line from intima into plaque (linear subgroup, Figure B).Sonazoid, perflurobutane microbubbles, was used as the contrast agent. We investigated the association between the neurological symptom, CEUS findings and histopathologic findings. Results: CEUS revealed enhanced plaque in 22 (73.3%) of 30 patients. 10 patients were spotty subgroup, and 12 patients were linear subgroup. Symptomatic patients were more frequent in enhanced group than non-enhanced group (82.6% vs. 50%, p=0.037).The amount of neovascularization was larger in enhanced group than in non-enhanced group (6.3±4.2/2.5mm 2 vs. 1.5±1.6/2.5 mm 2 , P=0.001, Figure C). Furthermore, the enhanced group had more macrophage aggregation (11.1±12.5% vs. 4.2±1.5%, P=0.001) and intraplaque hemorrhage (20.2±15.9% vs. 9.4±12.2%, P=0.031) compared with the non-enhanced group. 11 of the linear subgroup (91.7%) had fibrous cap rupture, but this was observed in only 20% of those with a spotty subgroup (P=0.001, Figure D). Symptom and other histopathological findings were not different between the two subgroups. Conclusions: Enhanced plaque on CEUS indicates vulnerable plaque. A linear pattern of enhanced plaque indicates plaque rupture. Enhanced plaque on CEUS should become a new surrogate marker of vulnerable carotid plaque and patients.