Extensive/internal contrast-agent enhancement on carotid ultrasound was associated with greater histological neovascularization than absent/peripheral enhancement (3.24 vs 1.82/mm2, p=0.005).
Observational (n=32)
Does contrast-enhanced ultrasound imaging correlate with histological intraplaque neovascularization in patients with carotid atherosclerosis?
Contrast-enhanced carotid ultrasound correlates with histological neovessel density and plaque echolucency, suggesting utility for risk stratification of carotid atherosclerosis.
Absolute Event Rate: 3.24% vs 1.82%
p-value: p=0.005
OBJECTIVES: This study was designed to evaluate contrast-enhanced ultrasound imaging of carotid atherosclerosis as a clinical tool to study intraplaque neovascularization. BACKGROUND: Plaque neovascularization is associated with plaque vulnerability and symptomatic disease; therefore, imaging of neovascularization in carotid atherosclerosis may represent a useful tool for clinical risk stratification and monitoring the efficacy of antiatherosclerotic therapies. METHODS: Thirty-two patients with 52 carotid plaques were studied by standard and contrast-enhanced ultrasound imaging. In 17 of these patients who underwent endarterectomy, the surgical specimen was available for histological determination of microvessel density by CD31/CD34 double staining. Plaque echogenicity and degree of stenosis at standard ultrasound imaging were evaluated for each lesion. Contrast-agent enhancement within the plaque was categorized as absent/peripheral (grade 1) and extensive/internal (grade 2). RESULTS: In the surgical subgroup, plaques with higher contrast-agent enhancement showed a greater neovascularization at histology (grade 2 vs. grade 1 contrast-agent enhancement: median vasa vasorum density: 3.24/mm(2) vs. 1.82/mm(2), respectively, p = 0.005). In the whole series of 52 lesions, echolucent plaques showed a higher degree of contrast-agent enhancement (p < 0.001). Stenosis degree was not associated with neovascularization at histology or with the grade of contrast-agent enhancement. CONCLUSIONS: Carotid plaque contrast-agent enhancement with sonographic agents correlates with histological density of neovessels and is associated with plaque echolucency, a well-accepted marker of high risk lesions, but it is unrelated to the degree of stenosis. Contrast-enhanced carotid ultrasound imaging may provide valuable information for plaque risk stratification and for assessing the response to antiatherosclerotic therapies, beyond that provided by standard ultrasound imaging.
Coli et al. (2008) conducted an observational in Carotid atherosclerosis (n=32). Extensive/internal contrast-agent enhancement (grade 2) vs. Absent/peripheral contrast-agent enhancement (grade 1) was evaluated on Histological microvessel density (vasa vasorum density) (p=0.005). Extensive/internal contrast-agent enhancement on carotid ultrasound was associated with greater histological neovascularization than absent/peripheral enhancement (3.24 vs 1.82/mm2, p=0.005).