Plaque Neovascularization Research Articles

Neovascularization as a Leading Mechanism of Intraplaque Hemorrhage and Carotid Plaque Destabilization: A Narrative Review.

Intraplaque neovascularization (IPN) is considered a leading mechanism causing carotid plaque destabilization. We provide an objective and comprehensive summary of the biology, imaging techniques, and treatment options related to carotid IPN. Plaque neovascularization has been reported to originate mainly from the adventitial vasa vasorum as a response to hypoxia. The leakage and rupture of neovessels lead to the formation of extravasations and foci of inflammation that destabilize the plaque. Vascular endothelial growth factor and its receptors are key regulators of neoangiogenesis. Neovascularization can be analyzed by advanced computed tomography and magnetic resonance imaging. The basic tools for the ultrasound assessment of IPN are contrast-enhanced ultrasound, superb microvascular imaging, and ultrasound molecular imaging. A promising direction of research seems to be the identification of patients with advanced plaque neovascularization. A simple test assessing low-velocity flow in the IPN can detect patients at risk of stroke before they experience rupture of defective neovessels and intracerebral embolism. In addition to surgical treatment, the stabilization of carotid atherosclerotic plaque can be supported pharmacologically. Statins have the best-documented role in this respect. The ideal moment of intensified therapeutic intervention in patients with previously stable carotid plaque is its increased neovascularization. However, the time frame in which intracerebral embolization may occur is unknown, and therapeutic intervention may be too late. The formation of deficient neovessels can currently be non-invasively evaluated with ultrasound. Superb microvascular imaging may change the clinical approach for asymptomatic patients at risk of cerebral ischemia.

Association of cardiovascular risk factors and intraplaque neovascularization in symptomatic carotid plaque.

Cardiovascular risk factors are known to contribute to the formation of atherosclerotic plaques, which can result in carotid stenosis. However, the extent to which these factors are associated with intraplaque neovascularization, a key indicator of plaque vulnerability, remains unclear. To investigate this relationship, a study was conducted utilizing contrast-enhanced ultrasound (CEUS) to assess intraplaque neovascularization in symptomatic patients. A cohort of 157 symptomatic patients underwent evaluation using Contrast-Enhanced Ultrasound (CEUS) imaging to assess carotid intraplaque neovascularization, which was quantified based on the degree of plaque enhancement. The collected data encompassed baseline patient characteristics, results from biochemical examinations, cardiovascular risk factors, and medication usage history. Regression analyses were conducted to elucidate the relationship between carotid plaque neovascularization and various cardiovascular risk factors. Patients with intraplaque neovascularization were more prone to have diabetes mellitus (OR 3.81, 95% CI 1.94-7.46, p < 0.001), dyslipidemia (OR 2.36, 95% CI 1.22-4.55, p = 0.011) and hypertension (OR 2.92, 95% CI 1.50-5.71, p = 0.002). Smoking increased the risk of having intraplaque neovascularization (OR 2.25, 95% CI 1.12-4.54, p = 0.023). Treatment with statins was significantly lower in patients with intraplaque neovascularization (OR 0.37, 95% CI 0.19-0.72, p = 0.003). In the multivariate analysis, diabetes mellitus (OR 3.27, 95% CI 1.10-9.78, p = 0.034) was independently related to the presence of intraplaque neovascularization. Meanwhile, compared to the patients in the first tertile of serum glucose (< 6.20 mmol/L), the patients in the third tertile (> 13.35 mmol/L) had the most significance of intraplaque neovascularization (OR 5.55, 95% CI 1.85-16.66, p = 0.002). The findings indicated that diabetes mellitus is a significant cardiovascular risk factor that is strongly associated with carotid intraplaque neovascularization.

Contrast-enhanced ultrasound evaluation of plaque vulnerability and the relationship between peripheral blood leukocytes.

To evaluate plaque vulnerability by carotid contrast-enhanced ultrasound (CEUS) and to analyze the correlation between plaque vulnerability and peripheral blood leukocyte classification. 135 patients with carotid plaque were examined by contrast-enhanced ultrasound. Plaque vulnerability was assessed by semiquantitative visual classification. Baseline clinical data and peripheral leukocyte classification were collected. Ordered logistic regression was used to analyze the correlation between plaque neovascularization grade and peripheral leukocyte classification count. There were significant differences in leukocyte, monocyte, neutrophil, mean platelet volume, lymphocyte, and neutrophil counts between different neovascular plaque grades and peripheral blood (P < 0.05). Correlation analysis showed that leukocyte, monocyte, and neutrophil counts were significantly positively correlated. The increase in plaque neovascularization is associated with an increase in circulating leukocytes, monocytes, and neutrophils. Therefore, CEUS combined with peripheral blood leukocytes may serve as an early warning of plaque vulnerability and provide a theoretical basis for clinical treatment.

Relationship between fibroblast growth factor in plasma and carotid plaque neovascularization: a pilot study.

Unstable atherosclerotic carotid plaques with intraplaque neovascularization (IPN) carry a substantial risk for ischemic stroke. Conventional ultrasound methods fall short in detecting IPN, where superb microvascular imaging (SMI) has emerged as a promising tool for both visualizing and quantification. High levels of fibroblast growth factor 23 (FGF-23) have, in observational studies, been suggested as related to cardiovascular morbidity and mortality. The association of FGF-23 to atherosclerotic carotid plaque instability remains relatively unexplored. A cohort of twenty-nine patients with ≥50% atherosclerotic carotid stenosis underwent conventional carotid ultrasound, SMI, and blood tests, including measurement of FGF-23 in plasma. Nineteen patients were characterized as symptomatic and ten as asymptomatic. Our major findings were: i) Higher FGF-23 levels were strongly correlated with increased SMI-assessed IPN. ii) Neo-vessel count recorded by quantitative SMI was positively correlated to increased FGF-23 levels, but not with basic FGF levels. (iii) In contrast, traditional risk factors for plaque instability exhibited no noteworthy associations with SMI-assessed IPN or with FGF-23 levels. This pilot study suggest the potential of FGF-23 as a valuable marker for neovascularization and atherosclerotic carotid plaque instability as a risk factor for ischemic stroke. Further research involving larger cohorts and prospective data is necessary to understand FGF-23's role in this context comprehensively.

What Is the Added Value of Carotid CEUS in the Characterization of Atherosclerotic Plaque?

Background and Objectives: Unstable atherosclerotic plaque in the arteries is one of the main risk factors for cerebral ischemia. Duplex ultrasound is a frequently used diagnostic method, but it has some limitations for microvascularization and neovascularization evaluation. The aim of this review was to evaluate the role of the new multiparametric US method-contrast-enhanced ultrasound (CEUS)-in atherosclerotic plaque instability verification. Materials and Methods: Original studies, reviews, and meta-analyses were included in this article. A total of 53 studies were retrieved; 29 were included in this study. Results: Carotid artery CEUS as a part of the multiparametric ultrasound method shows promising results and provides additional characteristics of soft- and high-risk atherosclerotic plaques; it can be advised in clinical practice for patients with carotid artery soft- and high-risk plaques. However, there are some limitations, such as extensive calcinosis with important acoustic shadows in carotid atherosclerotic plaque neovascularization diagnostics by CEUS. The added value of CEUS in the characterization of atherosclerotic plaque is that it indicates regions with high neovascularization and visualizes ulcerations on plaque surfaces, suggestive of increased instability risk.

Arterial Adventitial Vasa Vasorum Density Reflects The Progression Of Unstable Plaques: A Retrospective Clinical Study

Arterial adventitial vasa vasorum (AVV) plays an important role in the occurrence and development of atherosclerotic (AS) disease. AS is a systemic disease, and plaque is not only a local vascular event, but also occurs at multiple sites throughout the vascular bed. Currently, effective anti-AVV therapies are lacking. Therefore, we posed the following scientific questions: "does human carotid adventitial vasa vasorum density reflect plaque neovascularization and intimal-media hyperplasia in carotid?"; and "is it possible to reduce human AVV density by sonodynamic therapy (SDT)?" A retrospective study was conducted on 160 patients with carotid atherosclerosis. Duplex ultrasound scanning (DUS), contrast-enhanced ultrasound (CEUS), coronary angiography, and coronary CT angiography (CTA) were used for diagnosis and screening. Pearson correlation tests and Receiver operating characteristic (ROC) curve were used to analyze the relationships between AVV hyperplasia, vasa vasorum (VV) hyperplasia and the intima-media thickness (IMT). SDT was developed for the treatment of arterial AVV hyperplasia and AS plaques. The presence of local AVV in carotid unstable plaques correlated with the echogenic properties of the carotid plaque and the extent of plaque progression; Furthermore local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with acute coronary syndrome (ACS) events; Local AVV hyperplasia in patients with carotid atherosclerotic plaques was associated with coronary artery stenosis. Notably, SDT reduced local AVV hyperplasia and shrank the plaques in human femoral and carotid atherosclerotic lesions. The presence of AVV in human carotid arteries reflects the severity of carotid and coronary artery AS. Further, SDT can reduce the hyperplasia of local AVV in human femoral and carotid plaques.

Effect of combining evolocumab with statin on carotid intraplaque neovascularization in patients with premature coronary artery disease (EPOCH)

Background and aimsWe aimed to explore the effect of PCSK9 inhibitor based on the background of statin on carotid intraplaque neovascularization (IPN) assessed by serial contrast-enhanced ultrasound (CEUS) analysis in Chinese patients with premature coronary artery disease (PCAD). Methods41 patients were included to receive treatments with biweekly evolocumab (n = 22) or placebo (n = 19) in addition to statin therapy for 52 weeks. All patients were newly diagnosed with PCAD and treatments were initiated at baseline of the observations. Baseline and 52-week CEUS were acquired to measure the max plaque height (MPH) and IPN. The primary outcome was the 52-week IPN changes, the secondary endpoints included the 52-week MPH changes and major adverse cardiovascular events. ResultsThe mean ± SD age of the participants was 46.76 ± 8.56 years, and 61% (25/41) of patients were on statins before the start of the study. There was no statistically significant difference in the history of statins treatment and the initiated lipid-lowering therapy of atorvastatin and rosuvastatin between groups (p > 0.05). At 52 weeks, the evolocumab group showed a lower LDL level (0.84 ± 0.45 mmol/L vs. 1.58 ± 0.51 mmol/L, p < 0.001) and a greater decrease in percent reduction of LDL-C level (−65% vs. −32%) and a higher percent of achieving lipid-lowering target (95% vs. 53%, p < 0.05) compared with the placebo group. At 52 weeks, IPN (evolocumab group: 0.50 ± 0.60 vs. 1.50 ± 0.80, p < 0.001; placebo group: 0.79 ± 0.54 vs. 1.26 ± 0.65, p < 0.05) and MPH (evolocumab group: 2.01 ± 0.44 mm vs. 2.57 ± 0.90 mm, p < 0.05, placebo group: 2.21 ± 0.58 mm vs. 2.92 ± 0.86 mm, p < 0.05) reduced significantly in both groups from baseline to 52-week follow-up. IPN and MPH were decreased by both treatments. Still, there was no significant difference in delta (52 weeks - baseline) MPH by an ANOVA analysis between the two groups [evolocumab group: −0.56 mm (2.01 mm–2.57 mm); placebo group: −0.71 mm (2.21 mm–2.92 mm), p > 0.05]. In the evolocumab group, the change in the mean reduction of IPN from baseline [-1.00 (0.50–1.50) vs. −0.47 (0.79–1.26), p < 0.05] and the incidence of patients with carotid IPN decrease were significantly greater reduction (90% vs. 58%, p < 0.05). ConclusionsIf compared to placebo, the PCSK9 inhibitor evolocumab combined with statins resulted in a greater decrease in LDL-C and plaque neovascularization in Chinese patients with PCAD.

Study on the Consistency of Angiogenesis in Carotid Plaque Evaluated by Contrast-Enhanced Ultrasound and Superb Microvascular Imaging and Its Correlation With Stroke Occurrence.

This study aimed to investigate the value of contrast-enhanced ultrasound (CEUS) and superb microvascular imaging (SMI) in evaluating angiogenesis in carotid artery plaques and prognosis in stroke patients. Sixty-one patients with carotid atherosclerotic plaques were selected. All patients received conventional ultrasound, CEUS, and SMI examination, including 32 patients with cerebral infarction and 29 patients without cerebral infarction. The results of CEUS and SMI neovascularization of patients were graded 0, 1, and 2 points according to the image characteristics. The consistency between SMI results and CEUS results was evaluated, and the differences in neovascularization in carotid plaques between patients with cerebral infarction and those without cerebral infarction were compared. SMI showed that the neovascularization score in plaque was 0 point in 13 cases, 1 point in 24 cases, and 2 points in 24 cases. There were no significant differences in age, sex, plaque size, or echo between the two groups. There was no significant difference between the SMI and CEUS results, P > .05. The CEUS neovascularization grade of patients with cerebral infarction had a higher score, which was significantly different from that of patients without cerebral infarction, P < .05. The SMI neovascularization grade of patients with cerebral infarction had a higher score, which was significantly different from that of patients without cerebral infarction, P < .05. SMI can show neovascularization in plaques, with a significantly higher grade of neovascularization in those of patients with cerebral infarction than in those without cerebral infarction.

Extracellular vesicles in heart failure.

Physiologically, extracellular vesicles (EVs) have been implicated as crucial mediators of immune response, cell homeostasis, angiogenesis, cell differentiation and growth, and tissue repair. In heart failure (HF) they may act as regulators of cardiac remodeling, microvascular inflammation, micro environmental changes, tissue fibrosis, atherosclerosis, neovascularization of plaques, endothelial dysfunction, thrombosis, and reciprocal heart-remote organ interaction. The chapter summaries the nomenclature, isolation, detection of EVs, their biologic role and function physiologically as well as in the pathogenesis of HF. Current challenges to the utilization of EVs as diagnostic and predictive biomarkers in HF are also discussed.

Characteristics and evaluation of atherosclerotic plaques: an overview of state-of-the-art techniques.

Atherosclerosis is an important cause of cerebrovascular and cardiovascular disease (CVD). Lipid infiltration, inflammation, and altered vascular stress are the critical mechanisms that cause atherosclerotic plaque formation. The hallmarks of the progression of atherosclerosis include plaque ulceration, rupture, neovascularization, and intraplaque hemorrhage, all of which are closely associated with the occurrence of CVD. Assessing the severity of atherosclerosis and plaque vulnerability is crucial for the prevention and treatment of CVD. Integrating imaging techniques for evaluating the characteristics of atherosclerotic plaques with computer simulations yields insights into plaque inflammation levels, spatial morphology, and intravascular stress distribution, resulting in a more realistic and accurate estimation of plaque state. Here, we review the characteristics and advancing techniques used to analyze intracranial and extracranial atherosclerotic plaques to provide a comprehensive understanding of atheroma.

The human carotid atherosclerotic plaque: an observational review of histological scoring systems.

The atherosclerotic plaque is a complex dynamic pathological lesion of the arterial wall, characterized by multiple elementary lesions of different diagnostic and prognostic significance. Fibrous cap thickness, lipid necrotic core dimension, inflammation, intra-plaque hemorrhage (IPH), plaque neovascularization and endothelial dysfunction (erosions) are generally considered the most relevant morphological details of plaque morphology. In this review, the most relevant features able to discriminate between stable and vulnerable plaques at histological level are discussed. Retrospectively, we have evaluated the laboratory results from one hundred old histological samples from patients treated with carotid endarterectomy. These results were analyzed to assess elementary lesions that characterize stable and unstable plaques. A thin fibrous cap (<65 micron), loss of smooth muscle cells, collagen depletion, a large lipid-rich necrotic core, infiltrating macrophages, IPH and intra-plaque vascularization are identified as the most important risk factors associated with plaque rupture. Immunohistochemistry for smooth muscle actin (smooth muscle cell marker) and for CD68 (marker of monocytes/macrophages) and glycophorin (marker of red blood cells) are suggested as useful tools for an in deep characterization of any carotid plaque and for distinguishing plaque phenotypes at histology. Since patients with a carotid vulnerable plaque are at higher risk of developing vulnerable plaques in other arteries as well, the definition of the vulnerability index is underlined, in order to stratify patients at higher risk for undergoing cardiovascular events.

Natural Cell Patches: Melanin Nanoparticles for MR Imaging‐Guided Antiatherosclerosis Therapy via Attenuating Macrophage Pyroptosis (Adv. Funct. Mater. 13/2023)

Natural Cell Patches In article number 2212748, Longjiang Zhang and co-workers report a multifunctional nanoplatform cRGD-PEG-MNP (RpMP). RpMPs act like cell patches to suppress macrophage pyroptosis, thus potently ameliorating the development of atherosclerosis via targeting plaque neovascularization. Chelator-free Gd3+-RpMPs exhibit persistent T1-weighted contrast-enhanced efficiency and plaque resident on a 9.4 T Micro MR scanner. The presented nanoplatform possesses the potential for molecular theranostic in pyroptosis-related diseases.

Multimodal ultrasound-based carotid plaque risk biomarkers predict poor functional outcome in patients with ischemic stroke or TIA

BackgroundCarotid vulnerable plaque is an important risk factor for stroke occurrence and recurrence. However, the relationship between risk parameters related to carotid vulnerable plaque (plaque size, echogenicity, intraplaque neovascularization, and plaque stiffness) and neurological outcome after ischemic stroke or TIA is unclear. This study investigates the value of multimodal ultrasound-based carotid plaque risk biomarkers to predict poor short-term functional outcome after ischemic stroke or TIA.MethodsThis study was a single-center, prospective, continuous, cohort study to observe the occurrence of adverse functional outcomes (mRS 2–6/3–6) 90 days after ischemic stroke or TIA in patients, where the exposure factors in this study were carotid plaque ultrasound risk biomarkers and the risk factors were sex, age, disease history, and medication history. Patients with ischemic stroke or TIA (mRS ≤3) whose ipsilateral internal carotid artery stenosis was ≥50% within 30 days were included. All patients underwent multimodal ultrasound at baseline, including conventional ultrasound, superb microvascular imaging (SMI), and shear wave elastography (SWE). Continuous variables were divided into four groups at interquartile spacing for inclusion in univariate and multifactorial analyses. After completion of a baseline ultrasound, all patients were followed up at 90 days after ultrasound, and patient modified neurological function scores (mRSs) were recorded. Multivariate Cox regression and ROC curves were used to assess the risk factors and predictive power for predicting poor neurological function.ResultsSMI revealed that 20 (30.8%) patients showed extensive neovascularization in the carotid plaque, and 45 (69.2%) patients showed limited neovascularization in the carotid plaque. SWE imaging showed that the mean carotid plaque stiffness was 51.49 ± 18.34 kPa (23.19–111.39 kPa). After a mean follow-up of 90 ± 14 days, a total of 21 (32.3%) patients had a mRS of 2–6, and a total of 10 (15.4%) patients had a mRS of 3–6. Cox regression analysis showed that the level of intraplaque neovascularization and plaque stiffness were independent risk factors for a mRS of 2–6, and the level of intraplaque neovascularization was an independent risk factor for a mRS of 3–6. After correcting for confounders, the HR of intraplaque neovascularization level and plaque stiffness predicting a mRS 2–6 was 3.06 (95% CI 1.05–12.59, P = 0.041) and 0.51 (95% CI 0.31–0.83, P = 0.007), respectively; the HR of intraplaque neovascularization level predicting a mRS 3–6 was 6.11 (95% CI 1.19–31.45, P = 0.031). For ROC curve analysis, the mRSs for intraplaque neovascularization level, plaque stiffness, and combined application to predict 90-day neurological outcome ranged from 2 to 6, with AUCs of 0.73 (95% CI 0.59–0.87), 0.76 (95% CI 0.64–0.89) and 0.85 (95% CI 0.76–0.95), respectively. The mRSs for the intraplaque neovascularization level to predict 90-day neurological outcome ranged from 3 to 6, with AUCs of 0.79 (95% CI 0.63–0.95).ConclusionIntraplaque neovascularization level and plaque stiffness may be associated with an increased risk of poor short-term functional outcome after stroke in patients with recent anterior circulation ischemic stroke due to carotid atherosclerosis. The combined application of multiple parameters has efficacy in predicting poor short-term functional outcome after stroke.

Natural Cell Patches: Melanin Nanoparticles for MR Imaging‐Guided Antiatherosclerosis Therapy via Attenuating Macrophage Pyroptosis

AbstractPyroptosis, characterized by inflammasome activation, membrane Gasdermin D (GSDMD)‐pore formulation, and the rapid release of inflammatory cytokines, can induce plaque instability and atherosclerosis progression. Nevertheless, insights into the precise antiatherosclerosis therapies targeting pyroptosis remain limited. Here, a novel biomedical application of natural polyphenol melanin as a theranostic antipyroptosis defense nanoplatform for atherosclerosis is reported. Ultrasmall melanin nanoparticles are easily fabricated and functionalized with cyclo‐Arg‐Gly‐Asp‐d‐Tyr‐Lys conjugated polyethylene glycol to yield cRGD‐PEG‐MNPs (RpMPs) to target plaque neovascularization, which is confirmed by fluorescence imaging. Importantly, RpMPs act like cell patches to suppress pyroptosis in lipopolysaccharide‐stimulated macrophages by scavenging reactive oxygen species, downregulating the expression levels of pyroptosis‐related proteins (NLRP3, Caspase 1, and GSDMD) and reducing the leakage of inflammatory cytokines (interleukin‐1β, interleukin‐6, and tumor necrosis factor‐α). In vivo studies further reveal that RpMPs can ameliorate the development and improve the stability of atherosclerotic plaques via attenuating NLRP3‐stimulated pyroptosis and inducing an anti‐inflammatory phenotype in the aorta of ApoE−/− mice. Moreover, chelator‐free Gd3+‐RpMPs exhibit persistent T1‐weighted contrast‐enhanced efficiency and plaque resident on a 9.4 T Micro magnetic resonance scanner in murine atherosclerosis model. Overall, this study suggests the potential for using melanin to develop natural multifunctional nanoplatforms for molecular theranostic in atherosclerosis and other pyroptosis‐related diseases.

Retracted: Diagnostic Performance of Atherosclerotic Carotid Plaque Neovascularization with Contrast‐Enhanced Ultrasound: A Meta‐Analysis

Retracted: Diagnostic Performance of Atherosclerotic Carotid Plaque Neovascularization with Contrast‐Enhanced Ultrasound: A Meta‐Analysis

Association between Carotid Intraplaque Neovascularization Detected by Contrast-Enhanced Ultrasound and the Progression of Coronary Lesions in Patients Undergoing Percutaneous Coronary Intervention

It is thought that the progression of vulnerable plaque is due in part to neovascularization, and plaque vulnerability is a useful approach for classifying cardiovascular risk. The aim of this retrospective study was to evaluate the correlation between carotid intraplaque neovascularization (IPN) detected on contrast-enhanced ultrasound and the progression of coronary lesions in patients undergoing percutaneous coronary intervention (PCI). Contrast-enhanced ultrasound and angiography were performed in 131 patients undergoing PCI. All patients had angiograms obtained ≥12months after PCI, and progression was defined using those angiograms. On the basis of angiographic images, patients were divided into progression and nonprogression groups. IPN was graded from 0 to 3 according to each plaque's microbubble appearance and extent, detected using contrast-enhanced ultrasound. The plaque with the highest IPN was used for analysis. Logistic regression and receiver operating characteristic analyses were applied to evaluate risk factors for predicting the progression of coronary lesions in patients undergoing PCI. In the progression group, the numbers of patients with IPN values of 0, 1, 2, and 3 were one (3.3%), nine (30.0%), 16 (53.3%), and four (13.3%), respectively. Significant differences were found in maximum plaque height and IPN between groups. IPN and maximum plaque height were independent risk contributors to coronary lesion progression in patients undergoing PCI. The sensitivity, specificity, positive predictive value, and negative predictive value of IPN of 1.5 and to predict the progression of coronary lesions were 67%, 91%, 68%, and 89%, respectively. The area under the curve was 0.822. Carotid plaque neovascularization was correlated with the progression of coronary lesions in patients undergoing PCI. IPN is a clinically useful tool for detecting the progression of coronary lesions and for risk stratification, especially in patients >60years old.

The Value of Superb Microvascular Imaging and Contrast-enhanced Ultrasound for the Evaluation of Neovascularization in Carotid Artery Plaques

To compare the consistency between superb microvascular imaging (SMI) and contrast-enhanced ultrasound (CEUS) for the detection of neovascularization in carotid plaques of different thicknesses and to evaluate the applied value of these two methods for detecting neovascularization in carotid plaques in the clinic. A total of 45 patients with carotid artery plaques who were diagnosed in our hospital involving 76 hypoechoic plaques with a thickness ≥2.0 mm were selected. According to thickness, the plaques were divided into three groups: 2.0-2.5 mm, 2.5-3.0 mm and ≥3.0 mm. Each group underwent both SMI and CEUS, and two experienced sonographers (A and B) analyzed the ultrasound images to evaluate the neovascularization of carotid plaques. The amount of the neovascular signal was assessed using a semi-quantitative grading scale (vascularity grade: grade 0-3). SMI and CEUS were graded respectively according to the visual methods as follows: grade 0: no blood flow signal/enhancement within plaques; grade 1: a few blood flow signals/enhancement within plaques; grade 2: medium blood flow signals/enhancement within plaques; and grade 3: extensive blood flow signals/enhancement within plaques. Kappa consistency test was used to analyze the consistency of the grade of neovascularization in plaques between SMI with CEUS. Gamma rank correlation analysis was used to examine the correlation between neovascularization grade by SMI and CEUS in plaque and plaque thickness. Of these patients, 14 had unilateral plaques and 31 had bilateral plaques. The two sonographers were highly consistent in terms of applying SMI and CEUS methods for diagnosing neovascularization in carotid plaques (Kappa values were 0.736 and 0.680>0). Consistency was found between SMI and CEUS by sonographers (sonographer A: Kappa=0.823; sonographer B: Kappa=0.842) in evaluating the neovascular grade in the carotid plaques. SMI and CEUS grades were positively correlated with plaque thickness (sonographer A: γ=0.735 and 0.772; sonographer B: γ=0.805 and 0.798). Neovascularization in carotid plaques was successfully detected by SMI in a manner that concurred well with CEUS results. Our data indicate that both CEUS and SMI have high diagnostic value for assessing the neovascularization of plaques.

CCL14 exacerbates intraplaque vulnerability by promoting neovascularization in the human carotid plaque

ObjectiveTo examine the role of CCL14 in the neovascularization process and vulnerability progression within carotid plaques by investigating the mechanism of CCL14 regulation of VEGF-A. MethodsWe first performed histological analysis and immunohistochemical staining of human carotid plaque tissue to detect the expression of CCL14, JAK2, STAT3 and VEGF-A. We next examined the protein expression of CCL14, VEGF-A, JAK2, STAT3, and phosphorylation of JAK2 and STAT3 in human carotid atherosclerotic plaques by Western blotting. Finally, we performed in vitro culture of human umbilical vein endothelial cells (HUVEC). In the tube formation assay of HUVEC, we added CCL14 siRNA or VEGF-A siRNA to the culture medium using lentiviral transfection to knock down CCL14 or VEGF-A and grouped them for control assays, and detected the changes in the expression of the above proteins using Western blotting. ResultsHistological and Western blotting analysis of human carotid plaque samples showed that the expression of CCL14 and VEGF-A was higher in the vulnerable plaques than in stable plaques. In the in vitro cultures of HUVEC, CCL14 was found to increase the number and length of intercellularly generated tubular structures. CCL14 increases VEGF-A expression via activating JAK2/STAT3 signaling. ConclusionIn the human carotid plaques, CCL14 promotes angiogenesis by upregulation of VEGF-A via JAK2/STAT3 pathway and thus drives the progression of carotid plaques vulnerability.

Carotid Ultrasound Using Superb Microvascular Imaging to Identify Patients Developing In-Stent Restenosis After CAS

Background and purposeIn-stent restenosis (ISR) caused by in-stent intimal hyperplasia (ISH) may develop after carotid artery stenting (CAS), and often necessitates re-stenting. We investigated whether new ultrasound technique is useful for detecting carotid artery plaques prone to ISR. PurposeSuperb micro-vascular imaging (SMI) is a new color Doppler imaging technique for assessing low velocity blood flow such as neovascularization in carotid artery plaques. In this study, we attempted to identify associations between findings from carotid ultrasonography with SMI performed prior to CAS and in-stent restenosis after 6 months of CAS. MethodsThis study investigated 19 patients (18 men; mean age, 72.4 years). Preoperative plaque evaluation was performed by magnetic resonance imaging, ultrasonography, and carotid angiography. Follow up angiography was performed in all patients at 6 months after CAS. ISR was defined as ISH resulting in >50% stenosis based on European Carotid Surgery Trialists criteria. We investigated whether SMI was useful as a predictor of ISR by chi-square test. ResultsPreoperative mean stenosis rate according to North American Symptomatic Carotid Endarterectomy Trial methods in 19 patients was 61.3%. Neovascularization was observed on SMI in 10 patients (52.6%). Carotid angiography at 6 months after CAS revealed ISR in 4 patients, all of whom had shown neovascularization on SMI. A significant association was seen between findings of neovascularization on SMI and development of ISR (p = 0.033). In predicting ISR, neovascularization findings on SMI offered 100.0% sensitivity and 60.0% specificity. ConclusionsPreprocedural plaque characterization by carotid ultrasound with SMI appears useful for predicting ISR at 6 months after CAS.

Carotid Plaque Vulnerability Assessed by Contrast-Enhanced Ultrasound and Clinical Risk Factors

To evaluate the vulnerability of carotid plaque by contrast-enhanced ultrasound, to study the clinical risk factors of the plaque, and to analyze the relationship between plaque vulnerability and clinical indicators.244 patients with carotid plaque were selected for contrast-enhanced ultrasound examination, biochemical and other indicators were detected, and the stability of plaque was evaluated by semi-quantitative visual grading of intraplaque neovascularization (IPN), and correlation between plaque and each indicator was analyzed.Different grades of neovascularization in plaque had statistical differences with BMI, arm circumference, WHR, WBC, CRP, tHcy, TBIL, DBIL, SUA, LP (a) and DD (P<0.05). Correlation analysis showed that TBIL, DBIL were negatively correlated with the grading, while others were positively correlated.The expression levels of SUA, tHcy, TC, TG, LDL-C, LP (a), DD, WBC and CRP are closely related to contrast-enhanced ultrasound grading, which further indicated the vulnerability of plaque and provides theoretical basis for clinical treatment.