Wall Plaque Research Articles

The Relationship between Coronary Artery Wall Shear Strain and Plaque Morphology: A Systematic Review and Meta-Analysis.

Background and Aim: Arterial wall shear strain (WSS) has been proposed to impact the features of atherosclerotic plaques. The aim of this meta-analysis was to assess the impact of different types of WSS on plaque features in coronary artery disease (CAD). Methods: We systematically searched PubMed-Medline, EMBASE, Scopus, Google Scholar, and the Cochrane Central Registry, from 1989 up to January 2020 and selected clinical trials and observational studies which assessed the relationship between WSS, measured by intravascular ultrasound (IVUS), and plaque morphology in patients with CAD. Results: In four studies, a total of 72 patients with 13,098 coronary artery segments were recruited, with mean age 57.5 ± 9.5 years. The pooled analysis showed that low WSS was associated with larger baseline lumen area (WMD 2.55 [1.34 to 3.76, p < 0.001]), smaller plaque area (WMD −1.16 [−1.84 to −0.49, p = 0.0007]), lower plaque burden (WMD −12.7 [−21.4 to −4.01, p = 0.04]), and lower necrotic core area (WMD −0.32 [−0.78 to 0.14, p = 0.04]). Low WSS also had smaller fibrous area (WMD −0.79 [−1.88 to 0.30, p = 0.02]) and smaller fibro-fatty area (WMD −0.22 [−0.57 to 0.13, p = 0.02]), compared with high WSS, but the dense calcium score was similar between the two groups (WMD −0.17 [−0.47 to 0.13, p = 0.26]). No differences were found between intermediate and high WSS. Conclusions: High WSS is associated with signs of plaque instability such as higher necrotic core, higher calcium score, and higher plaque burden compared with low WSS. These findings highlight the role of IVUS in assessing plaque vulnerability.

Coronary CT Angiography and Carotid MRI Improve Phenotyping of Disease Extent Compared with ACC/AHA Risk Score Alone.

To determine the relationship between the American College of Cardiology/American Heart Association (ACC/AHA) risk score and plaque phenotype of the coronary and carotid arteries assessed directly using CT angiography and MRI. Asymptomatic subjects eligible for statin therapy by risk score were enrolled in a prospective study of disease burden using coronary artery calcium (CAC) scoring, coronary CT angiography, and MRI of the carotid arteries. Quartiles were calculated for noncalcified plaque, CAC, and average carotid wall volume and were compared with ACC/AHA risk quartiles. Two hundred three subjects were studied (60% men; mean age, 65 years). There were weak correlations between risk and carotid wall volume (Kendall tau = 0.29), noncalcified plaque (tau = 0.16), and CAC (tau = 0.33). ACC/AHA risk alone misclassified plaque extent compared with measurement by carotid wall volume, CAC, and noncalcified plaque in 22.1%, 24.1%, and 29.6% of subjects, respectively. On average, 13% of the subjects were underclassified, and 12.5% were overclassified. Approximately 25% of subjects had large discrepancies between ACC/AHA risk and plaque burden at imaging. These results suggest that clinical risk score models alone do not fully reflect the amount of atherosclerotic disease present.© RSNA, 2020See also the commentary by Truong and Villines in this issue.

Investigation of Computed-Tomography Based Predictors of Acute Stroke Related to Transcatheter Aortic Valve Replacement: Aortic Wall Plaque Thickness Might be a Predictive Parameter of Stroke.

Little information is available on computed tomography (CT)-based predictors of stroke related to transcatheter aortic valve replacement (TAVR). The objective of this study was to determine whether anatomical features of the aortic valve and aorta visualized by CT are predictive parameters of stroke. The study included 1270 patients who underwent preprocedural contrast-enhanced CT assessment and TAVR for severe aortic valve stenosis. Twenty-six patients (2.5%) who developed acute strokes that occurred within 48 hours after TAVR and 104 matched patients without strokes were identified, using 1:4 propensity-score matching. The degree of hypoattenuation in the aortic valve leaflets, calcium volume of the aortic valve, and plaque thickness in the aortic wall (the ascending aorta, aortic arch, and descending thoracic aorta) were assessed. There were no differences between the two groups in the degree of hypoattenuation in the aortic valve leaflets and calcium volume of the aortic valve. The plaque thickness of the aortic arch and descending aorta were greater in the stroke group than in the non-stroke group: aortic arch, 2.4 mm (IQR, 1.3-2.8 mm) vs 1.8 mm (IQR, 1.4-2.2 mm), respectively (P<.01); and descending aorta, 2.9 mm (IQR, 2.1-4.2 mm) vs 2.8 mm (IQR, 2.1-3.6 mm); respectively (P=.049). Aortic wall plaque thickness measured by contrast-enhanced CT might be a predictive parameter of strokes that occur within 48 hours after TAVR.

A fully coupled computational fluid dynamics – agent-based model of atherosclerotic plaque development: Multiscale modeling framework and parameter sensitivity analysis

BackgroundPeripheral Artery Disease (PAD) is an atherosclerotic disorder that leads to impaired lumen patency through intimal hyperplasia and the build-up of plaques, mainly localized in areas of disturbed flow. Computational models can provide valuable insights in the pathogenesis of atherosclerosis and act as a predictive tool to optimize current interventional techniques. Our hypothesis is that a reliable predictive model must include the atherosclerosis development history. Accordingly, we developed a multiscale modeling framework of atherosclerosis that replicates the hemodynamic-driven arterial wall remodeling and plaque formation. MethodsThe framework was based on the coupling of Computational Fluid Dynamics (CFD) simulations with an Agent-Based Model (ABM). The CFD simulation computed the hemodynamics in a 3D artery model, while 2D ABMs simulated cell, Extracellular Matrix (ECM) and lipid dynamics in multiple vessel cross-sections. A sensitivity analysis was also performed to evaluate the oscillation of the ABM output to variations in the inputs and to identify the most influencing ABM parameters. ResultsOur multiscale model qualitatively replicated both the physiologic and pathologic arterial configuration, capturing histological-like features. The ABM outputs were mostly driven by cell and ECM dynamics, largely affecting the lumen area. A subset of parameters was found to affect the final lipid core size, without influencing cell/ECM or lumen area trends. ConclusionThe fully coupled CFD-ABM framework described atherosclerotic morphological and compositional changes triggered by a disturbed hemodynamics.

Biofilm-forming bacteria in atherosclerotic plaques in patients with cardiovascular diseases and chronic periodontitis

The identification of viable, previously undetectable types of microbes in human atherosclerotic plaques provides new evidence of direct and indirect participation of microbiota in the etiopathogenesis of non-infectious human diseases. Purpose of the study. Isolation and determination of the composition of viable microbes in atherosclerotic plaques and comparative analysis with the microbiota of the oral fluid in patients with chronic generalized periodontitis (CP) and coronary artery disease (CAD). Materials and methods. Fragments of atherosclerotic plaques isolated during coronary artery bypass grafting in patients with coronary artery disease and chronic periodontitis were cultured in a fluid system under anaerobic conditions. Isolated microbes were identified using bacteriological methods of research and polymerase chain reaction. The presence of biofilms was evaluated by scanning electron microscopy. Results. Twelve patients with CP and CAD were examined. Biofilms containing genetic markers of at least one type of microbiota were isolated from all atherosclerotic plaques after cultivation in a fluid system and anaerobic conditions. They included DNA of periodontal pathogens, some pathogens of purulent-inflammatory diseases, herpesviruses and Candida spp., as well as viable microbes. In the examined patients, a comparative analysis of the composition of the isolated microbiota from atherosclerotic plaques and oral fluid microbes was performed. Conclusions. A method for modeling biofilms based on fluid technology allows detecting previously undetectable types of microbiota in the walls of blood vessels and atherosclerotic plaques in sufficient quantities to identify and study their properties.

353 In Vivo Like Coronary Phantoms With Disease and Anisotropic Behaviour

The main disadvantage of bench-top phantoms is their lack in disease and uniform tissue properties, causing inaccurate representation when testing stent implant for example. Here we replicate realistic arterial properties with lesions using 3D heterogenic multi-material soft-printing with fibre like microstructures. This “meta-material” concept to replicate anisotropic properties of coronary wall and soft plaque was established through computational modelling and 1kN load cell tensile testing to matched in vivo properties from literature. Size of fibre radii, number of fibres, their sinodal curve and material were all varied to replicate in vivo tissue properties. Without the fibre like micro-structures, the polymer base material exhibits a notably different stress-strain behaviour and values. Circumferential and longitudinal coronary artery properties were matched well (<0.01 MPA difference for 0.06 axial and 0.1 circumferential strain). Soft plaque was also replicated well for strains of up to 0.15 with less than 0.05 MPA difference. Hard calcified plaque can be printed. We were able to print the first patient-specific left main bifurcation with realistic wall properties and arterial soft and calcified plaque. In future, this will allow more accurate functional bench testing including flow and mechanical studies, such as stent implants, and allow better training opportunities.

Imaging of the Ruptured Aortic Aneurysm Wall and Atherosclerotic Plaque by High Resolution X-Ray Computed Tomography, the New Tool for Prevention of Acute Cardio-Vascular Events

Introduction - In the recent years a significant progress has been reached in the development of novel hybrid pixel detectors, which combine a sensor of high-Z material for efficient X-ray registration and a readout chip. This allows to achieve high spatial resolution and capability of instant signal processing.

Health literacy is independently and inversely associated with carotid artery plaques and cardiovascular risk.

Health literacy, the degree to which individuals understand and act upon health information, may have a pivotal role in the prevention of cardiovascular disease (CVD), with low health literacy potentially explaining poorer adherence to prevention guidelines. We investigated the associations between health literacy, ultrasound-detected carotid atherosclerosis and cardiovascular risk factors. Baseline data (cross-sectional analysis) from a randomized controlled trial, integrated within the Västerbotten Intervention Program, Northern Sweden, was used. We included 3459 individuals, aged 40 or 50 years with ≥1 conventional risk factor or aged 60 years old. The participants underwent clinical examination, blood sampling, carotid ultrasound assessment of intima-media wall thickness (CIMT) and plaque formation, and answered a questionnaire on health literacy - the Brief Health Literacy Screen. The European Systematic Coronary Risk Evaluation and Framingham Risk Score were calculated. About 20% of the participants had low health literacy. Low health literacy was independently associated with the presence of ultrasound-detected carotid artery plaques after adjustment for age and education, odds ratio (95% confidence interval) 1.54 (1.28-1.85), demonstrating a similar level of risk as for smoking. Health literacy was associated with CIMT in men. Low health literacy was associated with higher CVD risk scores. Sensitivity analyses with low health literacy set to 9% or 30% of the study sample, respectively, yielded essentially the same results. Low health literacy was independently associated with carotid artery plaques and a high level of CVD risk scores. Presenting health information in a fashion that is understood by all patients may improve preventive efforts.

Use of contrast-enhanced computed tomographic imaging to diagnose and evaluate Behçet's disease with vascular complications.

In the present study, multi-slice CT results of patients with Behçet's disease (BD) and vascular complications were retrospectively evaluated. From January 2016 to May 2018, 45 of 361 patients with BD were diagnosed with vascular involvement. The clinical background, laboratory parameters and response to therapy of those patients were assessed. The following characteristics of vascular aneurysms were analyzed: Maximum diameter, length, wall thickness, borders, luminal changes, mural thrombus, cystic change of the vessel walls, asymmetric bulging of the right part of the aortic wall (RP type) and calcific plaques. The 45 BD patients analyzed included 37 males and 8 females with a median age of 40 years (30–49 years). Significant differences were observed among genders regarding age, ocular disorders and digestive-tract ulceration. A total of 42 aneurysms were identified with a mean diameter of 43 mm. Most aneurysmal walls (88%) were homogeneously enhanced on contrast-enhanced CT. Comparison of groups classified by aortic and larger arterial aneurysms indicated that aneurysms occurring in the aorta were more likely to form a mural thrombus, have a thicker wall (P<0.001) and unclear borders (P=0.036), to be of the RP type (P=0.003) and have a longer extension (P=0.001) compared with those in larger arteries. Unclear border of the aneurysmal wall was the only radiologic predictor correlated with an elevated erythrocyte sedimentation rate (P<0.001). In conclusion, characteristic CT imaging features of aneurysms may help to diagnose vascular involvement of BD and assess its severity, particularly in the absence of the classical clinical manifestations.

P3109Coronary vulnerable plaque development is promoted by multidirectional wall shear stress

Abstract Aim Wall shear stress (WSS) has been widely associated with plaque development and destabilization. However, the multidirectionality of WSS, induced by the pulsatile nature of blood flow in combination with the arterial geometry, is rarely taken into account. The purpose of this study was to investigate the influence and predictive value of five (multidirectional) WSS parameters for coronary plaque progression and composition. Methods Familial hypercholesterolemic pigs (n=10, castrated male, 3 years old) were put on a high-fat diet and underwent imaging (near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), optical coherence tomography (OCT) and CT) of the three main coronary arteries at baseline and 10/12 months follow-up. IVUS-based lumen contours were combined with the centerline of artery as extracted from CT to obtain a 3D reconstruction of the coronary artery. Local flow velocity measurements were combined with the 3D-geometry of the coronary arterial lumen to calculate five multidirectional WSS parameters including: time average wall shear stress (TAWSS), oscilatory shear index (OSI), relative residence time (RRT), trans wall shear stress (TransWSS), cross flow index (CFI). For the analysis, arteries were divided into 3mm/45° sectors (n=3627). Per vessel each segment was classified as low, mid or high for each WSS metric based on the average value in the sector. Changes in wall thickness (WT) and plaque composition were assessed with NIRS-IVUS and OCT, and histology and related to the local (multidirectional) WSS. Results Half of the pigs developed lumen intruding, complex, lipid-rich plaques. In these pigs, coronary segments exposed to low baseline levels of TAWSS exhibited a significantly larger plaque growth per month compared to regions with either mid or high TAWSS (p&lt;0.05, see figure). Furthermore, plaque growth correlated positively with the multidirectional WSS metrics OSI, RRT and CFI, with high multidirectionality resulting in the largest plaque growth (see figure). The positive predictive values (PPV) of the WSS metrics for plaque presence (WT&gt;0.5mm) at follow up were 50% (low TAWSS), 48% (high OSI), 49% (high RRT), 47% (high CFI) and 43% (high transWSS). The PPVs for the presence of a fibroatheroma observed with histology were 61% (low TAWSS), 58% (high OSI), 61% (high RRT), 59% (high CFI) and 49% (high transWSS). Plaque growth vs. multidirectional WSS Conclusions This study shows that both low and multidirectional WSS promote the development of large and complex coronary atherosclerotic plaques with vulnerable characteristics. The high predictive values for fibrous cap atheroma development demonstrate the potential of multidirectional WSS metrics as a predictive clinical marker for vulnerable disease. Acknowledgement/Funding ERC- starter grant (grant agreement 310457)

In vivo alpha-V beta-3 integrin expression in human aortic atherosclerosis

ObjectivesIntraplaque angiogenesis and inflammation are key promoters of atherosclerosis and are mediated by the alpha-V beta-3 (αvβ3) integrin pathway. We investigated the applicability of the αvβ3-integrin receptor-selective positron emission tomography...

Carotid plaque load evaluation: comparison high resolution MR imaging with ultrasound

Objective To compare the image quality produced by MR high resolution vessel wall imaging (HR-VWI) and ultrasound (US) in evaluating carotid plaque load. Methods This prospective study enrolled 21 patients with carotid plaques undergoing HR-VWI and subsequent 2D US between August 2016 to January 2017 in Hebei General Hospitial. The plaque thickness (PT), lumen area (LA), wall area (WA) and total vessel area (TVA) of the plaques were measured and normalized wall index (NWI) was calculated on both HR-VWI images and US for those plaques with image quality score≥3 and matching between the two methods. The plaque load index was compared by using the independent sample t test or the non-parametric Wilcoxon test, and the correlation between the indexes was based on the Pearson test. Results Forty-five carotid plaques were matched with HR-VWI and US. There was no significant difference in PT, LA, WA, TVA and NWI detected by HR-VWI and ultrasound (P>0.05). The parameters measured by two methods were correlated (r values were 0.83, 0.85, 0.32, 0.83 and 0.59, P<0.05). Conclusion There is a good consistency between HR-VWI and conventional ultrasound in the measurement of carotid plaque load. Key words: Carotid artery thrombosis; Arteriosclerosis; Magnetic resonance imaging; Ultrasound

Automatic Carotid Artery Detection Using Attention Layer Region-Based Convolution Neural Network

Localization of vessel Region of Interest (ROI) from medical images provides an interactive approach that can assist doctors in evaluating carotid artery diseases. Accurate vessel detection is a prerequisite for the following procedures, like wall segmentation, plaque identification and 3D reconstruction. Deep learning models such as CNN have been widely used in medical image processing, and achieve state-of-the-art performance. Faster R-CNN is one of the most representative and successful methods for object detection. Using outputs of feature maps in different layers has been proved to be a useful way to improve the detection performance, however, the common method is to ensemble outputs of different layers directly, and the special characteristic and different importance of each layer haven’t been considered. In this work, we introduce a new network named Attention Layer R-CNN(AL R-CNN) and use it for automatic carotid artery detection, in which we integrate a new module named Attention Layer Part (ALP) into a basic Faster R-CNN system for better assembling feature maps of different layers. Experimental results on carotid dataset show that our method surpasses other state-of-the-art object detection systems.

Bioimaging of macro- and microelements in blood vessels with calcified plaque in atherosclerosis obliterans by LA-ICP-MS

In order to visualize the distribution of chemical elements in arterial walls and atherosclerotic plaque the laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was applied. As a result, the signals of structural elements in arterial wall and plaque (C, S, P, Ca), as well as trace and toxic elements (Mg, Fe, Mn, Cu, Zn, Co, Sr, Mo, Cd, Ba, Pb) in arterial walls were presented as two-dimensional maps. The bioimaging maps showed heterogeneous distribution of almost all analyzed elements. The elements which build up a plaque (Ca, P, Mg, Sr, Ba) are clearly distinguished from the arterial wall tissue, which in turn is composed mainly of C, S and trace elements. The highest signals of Zn were measured in the area connecting the arterial wall and atherosclerotic plaque which might be due to the presence of increased amount and activity of matrix metalloproteinases in arterial wall. The LA-ICP-MS provided data on the distribution of macro- and microelements, as well as toxic elements, in the soft tissues of arterial wall and the calcified plaque. The statistical analysis of data based on non-parametric tests and principal components analysis was performed, which revealed specific relations in distribution of measured elements.

Clinical evaluation of wall shear stress by ultrafast vector flow imaging in carotid atherosclerotic stenosis

Carotid plaque vulnerability assessment is an important factor in guiding the decision to perform carotid endarterectomy in case of asymptomatic stenosis. Ultrafast Ultrasound Imaging (UUI) offers the possibility of evaluating local flow velocities over an entire 2D image, allowing access to measure the wall shear stress (WSS). Our objective was to evaluate the feasibility of WSS measurement in a prospective series of patients with carotid stenosis. We used a linear probe (7.5 MHz, SuperSonic Imagine©). UUIacquisitions last 600 ms with 3 tilted plane waves for an effective frame rate of 5000 Hz. We evaluated the flow velocity in 5 areas of the carotid wall: common carotid artery (1), plaque ascent (2), peak (3), descent (4), and internal carotid artery (5) ( Figure 1 ). WSS was computed with the vector field speed. Shear stress measurement method was validated using a laminar flow phantom with laminar flow. Good correlation was found between in vitro measurement and the theoretical WSS values (R2 = 0.95; P < 0.001). 25 patients were included (mean age: 72 ± 5 years), with a mean percentage of stenosis of 75 ± 12% (NASCET). The maximum WSS value over one cardiac cycle follows the shape of the plaque with a progressive increase to a maximum value at the peak (2.12 ± 1.27 Pa). The post-stenotic descent zone has the lowest shear stress (0.57 ± 0.39 Pa), lower than the WSS values in the healthy zone (1.02 ± 0.36 Pa for the common carotid and 0.68 ± 0.39 Pa for the internal carotid artery) ( Figure 1 ). This method allowed the local and direct evaluation of the plaque's wall shear stress. Unlike the global evaluation of speed using conventional Doppler, these measurements make it possible to better characterize the haemodynamic conditions to better identify areas of vulnerability.

Comparison of non-contrast vessel wall imaging and 3-D time-of-flight MRA for atherosclerotic stenosis and plaque characterization within intracranial arteries

PurposeWe compared the ability of intracranial high-resolution vessel wall imaging (VWI) without gadolinium and 3-D time-of-flight (3D-TOF) MRA techniques to characterize intracranial arterial stenosis and arterial wall plaque consistent with atherosclerotic plaque. MethodsConsecutive intracranial VWI examinations performed within 2 months of a 3D-TOF exam with at least 1 noted plaque was included. Examinations assessed 17 vessel segments for plaque and diameters of stenotic and normal segments using double oblique reformatted images. Results were compared with the VWI and 3D-TOF exams considered the reference standard for plaque and luminal stenosis, respectively. ResultsAssessed segments totaled 286 from 17 patients. Proximal segment sensitivity and specificity for luminal stenosis detection with VWI was 92.5% and 82.1%, respectively, whereas for assessing plaque with 3D-TOF it was 59.4% and 98.3%, respectively. The mean intra-rater difference in luminal diameter measurements between VWI and 3D-TOF at normal segments and at the area of maximal stenosis was 0.02mm (SD 0.51mm) and 0.08mm (SD 0.66mm), respectively. ConclusionsIntracranial VWI demonstrated reasonably high sensitivity and specificity for luminal stenosis assessment using 3D-TOF as a reference standard, while 3D-TOF demonstrated low sensitivity for plaque detection. Our results suggest that VWI can be used for simultaneous assessment of luminal stenosis and plaque in the intracranial arteries.

3-D Strain Imaging of the Carotid Bifurcation: Methods and in-Human Feasibility

Atherosclerotic plaque development in the carotid artery bifurcation elevates the risk for stroke, which is often initiated by plaque rupture. The risk-to-rupture of a plaque is related to its composition. Two-dimensional non-invasive carotid elastography studies have found a correlation between wall strain and plaque composition. This study introduces a technique to perform non-invasive volumetric elastography in vivo. Three-dimensional ultrasound data of carotid artery bifurcations were acquired in four asymptomatic individuals using an electrocardiogram-triggered multislice acquisition device that scanned over a length of 35 mm (350 slices) using a linear transducer (L11-3, fc = 9 MHz). For each slice, three-angle ultrasound plane wave data were acquired and beamformed. A correction for breathing-induced motion was applied to spatially align the slices, enabling 3-D cross-correlation-based compound displacement, distensibility and strain estimation. Distensibility values matched with previously published values, while the corresponding volumetric principal strain maps revealed locally elevated compressive and tensile strains. This study presents for the first time 3-D elastography of carotid arteries in vivo.

Multi-factor decision-making strategy for better coronary plaque burden increase prediction: a patient-specific 3D FSI study using IVUS follow-up data.

Plaque progression and vulnerability are influenced by many risk factors. Our goal is to find a simple method to combine multiple risk factors for better plaque development prediction. Intravascular ultrasound data at baseline and follow-up were acquired from nine patients, and fluid-structure interaction models were constructed to obtain plaque wall stress/strain (PWS/PWSn) and wall shear stress (WSS). Two hundred fifty-four slices with noticeable change in plaque burden were selected for analyses. Data of six key morphological and biomechanical factors were extracted from each slice at baseline to predict plaque development measured by plaque burden increase (PBI) from baseline to follow-up. A multi-factor decision-making strategy was proposed to assign a binary predictive outcome YW (W represents any combination of these six factors) based on simple "threshold value" idea to predict the ground truth YPBI: YPBI = 1 if PBI > 0; YPBI = 0 otherwise. A fivefold cross-validation procedure was employed to identify the optimal predictor among all possible combinations. The results showed that PWS was the best single-factor predictor for PBI with a prediction accuracy of 63.0%. Among all 63 combinations, combining lipid percent, PWS and WSS gave the optimal predictor, achieving a prediction accuracy of 68.1%. This demonstrated that compared to single factor alone, integrating morphological and biomechanical factors would lead to higher prediction accuracy. The simple method could be extended to combine factors from different sources to improve prediction accuracy. Efforts in mechanical analysis and modeling automation are needed to bring this strategy closer to potential clinical applications.

In Vivo Intravascular Ultrasound-Based 3D Thin-Walled Model for Human Coronary Plaque Progression Study: Transforming Research to Potential Commercialization

Cardiovascular disease (CVD) is the leading cause of death in the world. Considerable research has been done linking various mechanical risk factors to plaque progression and rupture. However, methods transforming research results to clinical implementation are limited by time-consuming processes. In this study, a 3D thin-wall (TW) model was developed to approximate the 3D fluid–structure interaction (FSI) model to save time for clinical implementations. Results from one patient data (100 TW models) indicated that the relative errors of the average plaque wall stress (APWS) and strain were less than 7%, meanwhile the correlation results of the TW models were similar with that of the FSI models.

Association between ultrasound morphology of carotid plaque and carotid wall shear rate in patients with atherosclerosis of peripheral arteries

Aim– to investigate the relationship between the values of the carotid endothelial shear rate and ultrasound morphology of atherosclerotic plaques in carotid arteries.Material and methods. The study involved 70 patients with carotid atherosclerosis, including 43 males and 27 females. The average age of patients was (61.1±8.54) years. All patients underwent ultrasound triplex scanning of carotid arteries. Ultrasonic plaque morphology was evaluated using several ultrasonographic characteristics: uniformity of echotexture and echogenicity. We used the classification of G. Geraulakos et al. (1993). Endothelial shear rate in the common carotid artery was determined in accordance with the law of Hagen – Poiseuille.Results. Most patients (30) had a plaque type I, less frequently occurred plaque II (15) and III (20 patients) types. Homogeneous echo positive plaques corresponding to «stable» phenotype were found in 5 patients. In patients with plaque type I and II, endothelial shear rate values were 373 (305; 481) s–1 and 311 (282; 419) s–1 respectively. In the groups of patients with plaque– type III and IV endothelial shear rate was significantly higher – 500 (429; 556) s–1 and 470 (440; 512) s–1 respectively. Among patients with plaque with a predominance of echolucent component, more patients with type 2 diabetes mellitus were found (p=0.006).Conclusion. Carotid endothelial shear rate was significantly lower in patients with carotid atherosclerosis and echolucent plaques compared to those having predominantly hyperechoic plaque. Prevalence of diabetes mellitus type 2 was significantly higher in the group of patients with unstable plaque and low carotid endothelial shear rate.