Comparison of Carotid Atherosclerotic Plaque Characteristics between Symptomatic Patients with Transient Ischemic Attack and Stroke using Multi-Contrast Magnetic Resonance Imaging

Purpose:This study aimed to compare the characteristics of carotid plaques between patients with transient ischemic attack (TIA) and ischemic stroke using magnetic resonance (MR) imaging.Methods：Symptomatic patients with carotid atherosclerotic plaque who had a recent ischemic stroke or TIA were recruited and underwent carotid MR imaging. The characteristics of plaque morphology and compositions including intraplaque hemorrhage (IPH), lipid-rich necrotic-core (LRNC) and calcification were compared between TIA and stroke patients. Logistic regression was performed to relate the plaque characteristics to the types of ischemic events.Results:A total of 270 patients with TIA or ischemic stroke were recruited. Stroke patients had significantly higher prevalence of diabetes (42.2% vs. 28.2%, p=0.021), greater mean wall area (35.1 ± 10.1 mm2 vs. 32.0 ± 7.7mm2, p = 0.004), mean wall thickness (1.3 ± 0.2 mm vs. 1.2 ± 0.2 mm, p=0.001), maximum normalized wall index (NWI)(63.9% ± 6.0% vs. 62.2% ± 5.9%, p=0.023)and %volume of LRNC(9.7%± 8.2% vs. 7.4% ±7.9%, p=0.025)in carotid arteries compared to those with TIA. After adjusted for clinical factors, above characteristics of carotid arteries were significantly associated with the type of ischemic events. After further adjusting for maximum NWI, the association of %volume of LRNC and stroke subtype remained statistically significant (OR, 1.41; CI, 1.01-1.96; p=0.041).Conclusions:Ischemic stroke patients had larger plaque burden and greater proportion of LRNC in symptomatic carotid plaques compared to patients with TIA. This study suggests that ischemic stroke patients had more vulnerable plaques compared to those with TIA.

K-Means Clustering Algorithm-Based Detection of Carotid Atherosclerotic Plaque Using Contrast-Enhanced Ultrasound Images

The aim of this study was to investigate the diagnostic value of contrast-enhanced ultrasound (CEUS) based on the K-means clustering (KMC) algorithm for the vulnerability of carotid atherosclerotic plaque (CAA). In this study, 90 patients with CAA were enrolled into a control group (group A) and an experimental group (group B). The angiography method and KMC-based ultrasound detection were applied to diagnose the CAA patients from the two groups, respectively. The results showed that the sensitivity, specificity, and positive predictive value of patients from group B (92.3%, 90.1%, and 94.8%) for diagnosing CAA were obviously higher than those of patients from group A (81.4%, 88.6%, and 75.3%) ( P < 0.05 ). The detection rate of patients from group B (83%, 85%) was dramatically higher than that of patients from group A (65%, 71%) in terms of artery bifurcation and CAA ( P < 0.05 ). Besides, patients from group B were more satisfied with their diagnostic method than group A ( P < 0.05 ). In conclusion, the ultrasound detection method based on KMC had high sensitivity, specificity, and accuracy in the detection of CAA. In addition, ultrasound detection was better than angiography in the diagnosis of plaque in different parts, and it was worthwhile to apply the ultrasound detection method based on KMC in clinical practice.

Microecological preparation combined with an modified low-carbon diet improves glucolipid metabolism and cardiovascular complication in obese patients

Objective To investigate the impact of microecological preparation combined with modified low-carbon diet on the glucolipid metabolism and cardiovascular complication in obese patients. Methods From August 2017 to July 2020, 66 obese patients were recruited, and administrated with an modified low-carbon diet with (group A) or without (Group B) microecology preparation and a balanced diet in control group (group C) for 6 months. Meanwhile, 20 volunteers administrated with a balanced diet were recruited as the healthy control group (group D). Results After 6-month intervention, obese subjects in group A and B showed significant improvement of body and liver fat mass, reduction of serum lipid levels, intestinal barrier function markers, insulin resistance index (IRI), high blood pressure (HBP) and carotid intima thickness, as compared with subjects in group C. More importantly, subjects in group A had better improvement of vascular endothelial elasticity and intimal thickness than subjects in group B. However, these intervention had no effect on carotid atherosclerotic plaque. Conclusion Administration of microecological preparation combined with modified low-carbon diet had better improvement of intestinal barrier function, glucose and lipid metabolism, and cardiovascular complications than low-carbon diet in obese patients, but the effect of a simple low-carb diet on carotid atherosclerotic plaque need to be further addressed.

VEGF-Targeted Multispectral Optoacoustic Tomography and Fluorescence Molecular Imaging in Human Carotid Atherosclerotic Plaques

Vulnerable atherosclerotic carotid plaques are prone to rupture, resulting in ischemic strokes. In contrast to radiological imaging techniques, molecular imaging techniques have the potential to assess plaque vulnerability by visualizing diseases-specific biomarkers. A risk factor for rupture is intra-plaque neovascularization, which is characterized by overexpression of vascular endothelial growth factor-A (VEGF-A). Here, we study if administration of bevacizumab-800CW, a near-infrared tracer targeting VEGF-A, is safe and if molecular assessment of atherosclerotic carotid plaques in vivo is possible using multispectral optoacoustic tomography (MSOT). Healthy volunteers and patients with symptomatic carotid artery stenosis scheduled for carotid artery endarterectomy were imaged with MSOT. Secondly, patients were imaged two days after intravenous administration of 4.5 bevacizumab-800CW. Ex vivo fluorescence molecular imaging of the surgically removed plaque specimen was performed and correlated with histopathology. In this first-in-human MSOT and fluorescence molecular imaging study, we show that administration of 4.5 mg bevacizumab-800CW appeared to be safe in five patients and accumulated in the carotid atherosclerotic plaque. Although we could visualize the carotid bifurcation area in all subjects using MSOT, bevacizumab-800CW-resolved signal could not be detected with MSOT in the patients. Future studies should evaluate tracer safety, higher doses of bevacizumab-800CW or develop dedicated contrast agents for carotid atherosclerotic plaque assessment using MSOT.