Abstract 9313: Contrast-Enhanced Ultrasound Imaging of Carotid Plaque Neovascularization is Useful for Identification of High-Risk Patients for Atherosclerotic Cardiovascular Diseases

Abstract

Increased neovascularization in atherosclerotic plaques represents a feature of unstable plaques. Contrast-enhanced ultrasound (CEU) could be a potential technique for imaging plaque neovascularization in the carotid artery. This study examined whether CEU of the carotid artery may provide information of risk of cardiovascular diseases. Methods and Results: A total of 117 patients with CAD and a carotid plaque (IMT > 1.1 mm) underwent CEU study of the carotid artery. The carotid CEU was performed using perfluorobutane microbubbles as an ultrasound contrast agent and harmonic imaging software. The intra-plaque neovascularization was identified based on the rapid movement of the echogenic reflectors of microbubbles within the plaque. The plaque neovascularization was graded: Grade (G) 0, no visible microbubbles within the plaque; G1, moderate microbubbles confined to plaque adventitial side and/or shoulder; G2, extensive microbubbles throughout the plaque. In a total of 252 plaques from the study patients, the G1 plaque neovascularization was noted in 51 plaques (20%) and G2 in 27 plaques (11%). Patients with higher grade of the plaque neovascularization had higher prevalence of smoking, older age, higher levels of LDL-C and HbA1c, higher systolic blood pressure, greater PWV and carotid IMT (p < 0.05 in all). In logistic regression analysis, the G1/G2 plaque neovascularization was associated with acute coronary syndromes, multi-vessel coronary disease, chronic total coronary occlusions, ASO and previous stroke (OR 1.5, 2.0, 1.8, 2.2 and 1.6, 95% CI 1.2-2.5, 1.5-2.8, 1.1-3.1, 1.4-3.4 and 1.2-2.9, respectively, p < 0.01 in all), that was independent of carotid IMT. The change in plaque neovascularization during 6 months was examined in a subgroup of 30 patients. Plaque neovascularization regressed in 16 ( 80%) of 20 plaques graded as G1/G2 of 16 patients taking statin, while the regression did not occur in any plaques in 14 patients taking no statin. The carotid IMT did not change in either patients with or without statin treatment. Conclusions: The contrast-enhanced ultrasound study of the carotid artery may provide valuable information for risk status of systemic atherosclerosis and for efficacy of anti-atherosclerotic treatment beyond carotid IMT.