Stable Plaque Research Articles

Differential expression profile of miRNAs between stable and vulnerable plaques of carotid artery stenosis patients.

Plaque vulnerability is associated with the degree of carotid artery stenosis (CS) and the risk of stroke. MicroRNAs (miRNAs) exert critical functions in disease progression, although only a few miRNAs have been well identified in CS. Therefore, this study aimed to investigate the differential expression profile of miRNAs and their potential functions in plaques of CS patients. Three CS patients with stable plaques and three patients with vulnerable plaques who underwent carotid endarterectomy were enrolled in this study. Differentially expressed miRNAs (DEmiRNAs) between patients with stable and vulnerable plaques were determined using small RNA sequencing. Target genes of DEmiRNAs were predicted and submitted to functional analyses. Validation of dysregulated DEmiRNAs was determined using quantitative real-time polymerase chain reaction (qRT-PCR). After sequencing, 76 DEmiRNAs were identified in vulnerable plaques, including 53 upregulated miRNAs and 23 downregulated miRNAs. Next, 23,495 target genes of the identified DEmiRNAs were predicted and functionally analyzed. This indicated that the target genes of the identified DEmiRNAs were mainly enriched in protein phosphorylation, transcription, nitrogen compound metabolism, endocytosis and autophagy, and related to signaling pathways of Hippo, MAPK, insulin, TGF-β, FoxO, AMPK and p53. Furthermore, qRT-PCR results for six miRNAs showed that five (83%) of them (hsa-miR-511-5p, hsa-miR-150-5p, hsa-miR-378a-5p, hsa-miR-365b-5p and hsa-miR-6511b-5p) were consistent with the sequencing results. Differential expression profiles and potential function of miRNAs associated with plaque stability in CS patients are identified for the first time, which should help to understand the regulatory mechanism of plaque stability in CS.

Comparative morphometric analysis of contents mononuclear cells in unstable and in stable atherosclerotic lesions

BACKGROUND: Recent research results indicate that inflammatory cellular responses can play a significant role in the pathogenesis of atherosclerosis in humans and experimental animals, with a predominance in infiltrates of lymphocytes and monocytes/macrophages that contribute to destructive processes in the vascular wall. However, no comparative, differentiated morphometric analysis of the content of mononuclear cells in unstable and stable atherosclerotic lesions has been carried out so far.
 AIM: Carrying out comparative histological and morphometric examination of quantitative content of lymphocytes and macrophages in normal vascular wall, in lipid stain, in unstable and in stable atherosclerotic lesions.
 MATERIALS AND METHODS: The study material was samples taken during 15 autopsies aged 56 to 71 years who died from acute cardiovascular failure of atherosclerotic etiology. A comparative histological and morphometric study of the content of mononuclear cells: lymphocytes and macrophages in normal areas of the vascular wall, in lipid stains, in unstable and stable atherosclerotic lesions was carried out a total of 50 tissue samples stained with hematoxylin and eosin.
 RESULTS: A sharp increase in the content of studied cells in intima, atheromatous nucleus and adventition in unstable atherosclerotic plaques was revealed. In normal areas of the vascular wall, in initial atherosclerotic lesions and in stable plaques, the number of macrophages and lymphocytes is small.
 CONCLUSIONS: In general, the results obtained are well consistent with the literature and suggest in favor of the need for lymphocytes and macrophages to form immuno-inflammatory reactions in the formation of unstable atherosclerotic lesions in humans.

ANGPTL4 stabilizes atherosclerotic plaques and modulates the phenotypic transition of vascular smooth muscle cells through KLF4 downregulation

Atherosclerosis, the leading cause of death, is a vascular disease of chronic inflammation. We recently showed that angiopoietin-like 4 (ANGPTL4) promotes cardiac repair by suppressing pathological inflammation. Given the fundamental contribution of inflammation to atherosclerosis, we assessed the role of ANGPTL4 in the development of atherosclerosis and determined whether ANGPTL4 regulates atherosclerotic plaque stability. We injected ANGPTL4 protein twice a week into atherosclerotic Apoe−/− mice and analyzed the atherosclerotic lesion size, inflammation, and plaque stability. In atherosclerotic mice, ANGPTL4 reduced atherosclerotic plaque size and vascular inflammation. In the atherosclerotic lesions and fibrous caps, the number of α-SMA(+), SM22α(+), and SM-MHC(+) cells was higher, while the number of CD68(+) and Mac2(+) cells was lower in the ANGPTL4 group. Most importantly, the fibrous cap was significantly thicker in the ANGPTL4 group than in the control group. Smooth muscle cells (SMCs) isolated from atherosclerotic aortas showed significantly increased expression of CD68 and Krüppel-like factor 4 (KLF4), a modulator of the vascular SMC phenotype, along with downregulation of α-SMA, and these changes were attenuated by ANGPTL4 treatment. Furthermore, ANGPTL4 reduced TNFα-induced NADPH oxidase 1 (NOX1), a major source of reactive oxygen species, resulting in the attenuation of KLF4-mediated SMC phenotypic changes. We showed that acute myocardial infarction (AMI) patients with higher levels of ANGPTL4 had fewer vascular events than AMI patients with lower levels of ANGPTL4 (p < 0.05). Our results reveal that ANGPTL4 treatment inhibits atherogenesis and suggest that targeting vascular stability and inflammation may serve as a novel therapeutic strategy to prevent and treat atherosclerosis. Even more importantly, ANGPTL4 treatment inhibited the phenotypic changes of SMCs into macrophage-like cells by downregulating NOX1 activation of KLF4, leading to the formation of more stable plaques.

Pericoronary Adipose Tissue Attenuation in Patients With Acute Coronary Syndrome Versus Stable Coronary Artery Disease.

Pericoronary adipose tissue (PCAT) attenuation has been associated with coronary inflammation and can be evaluated with coronary computed tomography angiography. The aims of this study were to compare the PCAT attenuation across precursors of culprit and nonculprit lesions of patients with acute coronary syndrome versus stable coronary artery disease (CAD). In this case-control study, patients with suspected CAD who underwent coronary computed tomography angiography were included. Patients who developed an acute coronary syndrome within 2 years after the coronary computed tomography angiography scan were identified, and patients with stable CAD (defined as any coronary plaque ≥30% luminal diameter stenosis) were 1:2 propensity score matched for age, sex, and cardiac risk factors. The mean PCAT attenuation was analyzed at lesion level and compared between precursors of culprit lesions, nonculprit lesions, and stable coronary plaques. In total, 198 patients (age 62±10 years, 65% male) were selected, including 66 patients who developed an acute coronary syndrome and 132 propensity matched patients with stable CAD. Overall, 765 coronary lesions were analyzed (culprit lesion precursors: n=66; nonculprit lesion precursors: n=207; and stable lesions: n=492). Culprit lesion precursors had larger total plaque volume, fibro-fatty plaque volume, and low-attenuation plaque volume compared to nonculprit and stable lesions. The mean PCAT attenuation was significantly higher across culprit lesion precursors compared to nonculprit and stable lesions (-63.8±9.7 Hounsfield units versus -68.8±10.6 Hounsfield units versus -69.6±10.6 Hounsfield units, respectively; P<0.001), whereas the mean PCAT attenuation around nonculprit and stable lesions was not significantly different (P=0.99). The mean PCAT attenuation is significantly increased across culprit lesion precursors in patients with acute coronary syndrome, compared to nonculprit lesions of these patients and to lesions of patients with stable CAD, which may suggest a higher intensity of inflammation. PCAT attenuation on coronary computed tomography angiography may be a novel marker to identify high-risk plaques.

Atherosclerosis, Cardiovascular Disorders and COVID-19: Comorbid Pathogenesis.

The article describes how atherosclerosis and coronavirus disease 19 (COVID-19) may affect each other. The features of this comorbid pathogenesis at various levels (vascular, cellular and molecular) are considered. A bidirectional influence of these conditions is described: the presence of cardiovascular diseases affects different individuals' susceptibility to viral infection. In turn, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can have a negative effect on the endothelium and cardiomyocytes, causing blood clotting, secretion of pro-inflammatory cytokines, and thus exacerbating the development of atherosclerosis. In addition to the established entry into cells via angiotensin-converting enzyme 2 (ACE2), other mechanisms of SARS-CoV-2 entry are currently under investigation, for example, through CD147. Pathogenesis of comorbidity can be determined by the influence of the virus on various links which are meaningful for atherogenesis: generation of oxidized forms of low-density lipoproteins (LDL), launch of a cytokine storm, damage to the endothelial glycocalyx, and mitochondrial injury. The transformation of a stable plaque into an unstable one plays an important role in the pathogenesis of atherosclerosis complications and can be triggered by COVID-19. The impact of SARS-CoV-2 on large vessels such as the aorta is more complex than previously thought considering its impact on vasa vasorum. Current information on the mutual influence of the medicines used in the treatment of atherosclerosis and acute COVID-19 is briefly summarized.

Single-cell atlas reveals different immune environments between stable and vulnerable atherosclerotic plaques.

Regardless of the degree of stenosis, vulnerable plaque is an important cause of ischemic stroke and thrombotic complications. The changes of the immune microenvironment within plaques seem to be an important factor affecting the characteristics of the plaque. However, the differences of immune microenvironment between stable and vulnerable plaques were remained unknown. In this study, RNA-sequencing was performed on superficial temporal arteries from 5 traumatic patients and plaques from 3 atherosclerotic patients to preliminary identify the key immune response processes in plaques. Mass cytometry (CyTOF) technology was used to explore differences in immune composition between 9 vulnerable plaques and 12 stable plaques. Finally, immunofluorescence technique was used to validate our findings in the previous analysis. Our results showed that more CD86+CD68+ M1 pro-inflammatory macrophages were found in vulnerable plaques, while CD4+T memory cells were mainly found in stable plaques. In addition, a CD11c+ subset of CD4+T cells with higher IFN-r secretion was found within the vulnerable plaque. In two subsets of B cells, CD19+CD20-B cells in vulnerable plaques secreted more TNF-a and IL-6, while CD19-CD20+B cells expressed more PD-1 molecules. In conclusion, our study suggested that M1-like macrophages are the major cell subset affecting plaque stability, while functional B cells may also contribute to plaque stability.

The Correlation between Increased Expressions of NLRP3 Inflammasome Components in Peripheral Blood Mono-Nuclear Cells and Plaque Vulnerability in Human Carotid Atherosclerosis.

We aimed to determine whether NLRP3 inflammasomes in peripheral blood mononuclear cells (PBMC) were associated with carotid plaque instability in carotid atherosclerosis patients. Consecutive 38 carotid atherosclerosis with vulnerable plaques, 22 carotid atherosclerosis with stable plaques, and 40 healthy subjects with no carotid or coronary artery stenosis were enrolled. They were referred to the Second Hospital of Dalian Medical University from 2013-2019. Carotid plaques were evaluated by modified plaque vulnerability risk score (MPVRS) and pathological assessment. The mRNA and protein expression of NLRP3 inflammasome components in PBMC were determined by quantitative real time PCR and Western blot analysis or ELISA. When consecutive study subjects undergoing carotid endarterectomy were divided into stable (≤4) and unstable (>4) plaque groups according to the MPVRS, the unstable plaque group had significantly raised mRNA and protein expression of NLRP3 inflammasome components in PBMC as compared with the stable plaque group and healthy subject group. Furthermore, subjects with higher NLRP3 protein expression in PBMC had greater incidence of cerebrovascular events. Increased NLRP3 inflammasome components in PBMC is associated with instability of human carotid atherosclerotic plaques, suggesting NLRP3 inflammasome as a potential biomarker for monitoring carotid plaque instability.

The Involvement of Cx43 in JNK1/2-Mediated Endothelial Mechanotransduction and Human Plaque Progression.

Atherosclerotic lesions preferentially develop at bifurcations, characterized by non-uniform shear stress (SS). The aim of this study was to investigate SS-induced endothelial activation, focusing on stress-regulated mitogen-activated protein kinases (MAPK) and downstream signaling, and its relation to gap junction proteins, Connexins (Cxs). Human umbilical vein endothelial cells were exposed to flow ("mechanical stimulation") and stimulated with TNF-α ("inflammatory stimulation"). Phosphorylated levels of MAPKs (c-Jun N-terminal kinase (JNK1/2), extracellular signal-regulated kinase (ERK), and p38 kinase (p38K)) were quantified by flow cytometry, showing the activation of JNK1/2 and ERK. THP-1 cell adhesion under non-uniform SS was suppressed by the inhibition of JNK1/2, not of ERK. Immunofluorescence staining and quantitative real-time PCR demonstrated an induction of c-Jun and c-Fos and of Cx43 in endothelial cells by non-uniform SS, and the latter was abolished by JNK1/2 inhibition. Furthermore, plaque inflammation was analyzed in human carotid plaques (n = 40) using immunohistochemistry and quanti-gene RNA-assays, revealing elevated Cx43+ cell counts in vulnerable compared to stable plaques. Cx43+ cell burden in the plaque shoulder correlated with intraplaque neovascularization and lipid core size, while an inverse correlation was observed with fibrous cap thickness. Our results constitute the first report that JNK1/2 mediates Cx43 mechanoinduction in endothelial cells by atheroprone shear stress and that Cx43 is expressed in human carotid plaques. The correlation of Cx43+ cell counts with markers of plaque vulnerability implies its contribution to plaque progression.

PS-C28-6: HIGH TESTOSTERONE AND LOW ESTRADIOL SERA LEVELS ARE ASSOCIATED WITH UNSTABLE PLAQUE COMPOSITION IN MEN WITH SEVERE CAROTID ATHEROSCLEROSIS

Background and Objectives: Ischemic strokes caused by the rupture of unstable atherosclerotic plaques in the carotid arteries, are leading causes of mortality and disability worldwide. Sex differences exist in plaque composition, where men are more likely to develop unstable plaques than women. Sex hormones affect vascular reactivity and inflammation, but it remains unclear if they are involved in plaque instability and how their role differs in men and women. Herein, we investigated the association between circulating endogenous sex hormone levels and plaque composition/instability in men and women with severe carotid atherosclerosis. Design and method: Pre-operative fasting blood samples and plaque specimens were collected from post-menopausal women and men greater than 55 years old with severe carotid atherosclerosis who underwent a carotid endarterectomy at McGill-affiliated hospitals in Montreal, Canada. Plaque composition and stability were examined by experienced vascular pathologists according to gold-standard histological classifications. Liquid chromatography-tandem mass spectrometry-based methods were developed to quantify endogenous sex hormones, 17ß-estradiol (E2), testosterone, androstenedione, and dehydroepiandrosterone, in sera samples. Results: Subjects (n = 460) had a mean age of 71.0 ± 9.0, were 68.9% male, and had various comorbidities (hypercholesterolemia [82.6%], hypertension [84.6%], type 2 diabetes [34.5%]). Clinical characteristics were similar among post-menopausal women (n = 143) and men (n = 317) with stable versus unstable plaques. Men had a significantly greater proportion of unstable versus stable plaques compared to women (men unstable: 61.5%, women unstable: 41.3%; P &lt; 0.001), characterized predominantly by a large lipid-rich core, hemorrhage, and high presence of inflammatory cell infiltration. Men with unstable plaques had significantly higher levels of testosterone than men with stable plaques (P = 0.004). In men, testosterone levels were inversely associated with fibrosis (P &lt; 0.05), while directly associated with unstable plaque features, including greater lipid core size (P &lt; 0.05), and a greater presence of foam cells (P &lt; 0.05), neovascularization (P &lt; 0.01), and plaque (P &lt; 0.01) and cap inflammation (P &lt; 0.05). No associations were observed between testosterone levels and plaque features in women. Endogenous E2 levels were inversely associated with neovascularization (P &lt; 0.05) and plaque and cap inflammation (P &lt; 0.001) in men, while inversely associated with fibrosis levels in women (P &lt; 0.05). Conclusion: Our findings suggest that higher testosterone and lower E2 levels are associated with unstable plaque composition in men with carotid atherosclerotic disease and may partly explain the higher proportion of unstable plaques observed among men than women of similar age and comorbidity status. Instead, in women, estradiol appears to play a detrimental role in plaque instability by inversely affecting fibrous tissue levels (a key stabilizing feature of plaques).

LncRNA PCA3 Suppressed Carotid Artery Stenosis and Vascular Smooth Muscle Cell Function via Negatively Modulating the miR-124-3p/ITGB1 Axis.

Due to the hidden pathogen, carotid artery stenosis (CAS) always occurred at an advanced stage leading to serious sequelae and even deaths. The significance of long noncoding RNA (lncRNA) prostate cancer antigen 3 (PCA3) in CAS incidence and progression were evaluated aiming to explore a potential target for its therapy. Serum samples were collected from 83 asymptomatic CAS patients and 52 healthy individuals and PCA3 was compared using polymerase chain reaction (PCR). The PCA3 levels were compared between stable and unstable plaque in CAS patients. The effect of PCA3 on vascular smooth muscle cells (VSMCs) proliferation and motility was assessed by CCK8 and transwell assay. PCA3 was downregulated in CAS patients and their unstable plaque tissues compared with healthy individuals and stable plaque, respectively. Reduced PCA3 could discriminate CAS patients with relatively high sensitivity and specificity and were associated with higher total cholesterol level and stenosis degree, unstable plaque, and complications. PCA3 downregulation predicted the adverse outcomes of CAS patients. In VSMCs, overexpressing PCA3 significantly suppressed cell proliferation, migration, and invasion, which was alleviated by miR-124-3p/ITGB1 axis. PCA3 served as a biomarker of CAS and regulates the function of VSMCs through sponging miR-124-3p/ITGB1 and indirectly influence the stability of plaque.

S-07-3: THE TESTOSTERONE-ANDROGEN RECEPTOR PATHWAY IS ASSOCIATED WITH CAROTID ATHEROSCLEROTIC PLAQUE INSTABILITY IN MEN WITH SEVERE CAROTID ATHEROSCLEROSIS

Objective: Carotid atherosclerotic plaques can be stable or unstable; the latter more likely to rupture resulting in strokes. Sex differences exist in carotid plaque morphology and composition: carotid plaques of men tend to be more unstable than of women, who tend to have more fibrous and stable plaques. Yet, women experience greater morbidity and mortality rates post-stroke. Given that sex hormones exert pleiotropic effects on the cell types involved in the atherosclerotic process, and given that estradiol is largely atheroprotective in women, we hypothesize that sex hormones and their receptors may affect plaque instability. Design and Methods: In this cross-sectional study, we measured sex hormones in the circulation and their receptors in the plaque of older men and postmenopausal women undergoing a carotid endarterectomy (n = 160). Using liquid chromatography mass spectrometry, circulating estradiol, testosterone, dehydroepiandrosterone (DHEA), and androstenedione were measured in blood samples. Plaques collected post-operatively were classified into 4 groups (n = 40/group): women with stable, women with unstable plaques, men with stable, and men with unstable plaques. Protein expression of estrogen receptor α (ER-α), estrogen receptor β (ER-β), G protein-coupled estrogen receptor (GPER), and androgen receptor (AR) was quantified using immunohistochemistry and western blot analysis. Plaque sex hormone receptor mRNA expression was assessed using qRT-PCR. Results: Men with unstable plaques demonstrated greater circulating concentrations of testosterone and androstenedione compared to men with stable plaques (P = 0.02 and P = 0.047, respectively). Unstable plaques in men demonstrated significantly less AR and ER-α mRNA expression compared to stable plaques from men (P = 0.0003 and P = 0.042, respectively) and compared to unstable plaques from women (P = 0.0088 and P = 0.002). Yet, AR, ER-α, ER-β, and GPER protein expression was significantly greater in unstable plaques from men compared to stable plaques from men (P = 0.039, P = 0.006, P &lt; 0.0001, and P = 0.0002, respectively) and compared to unstable plaques from women (P = 0.005, P = 0.041, P = 0.028, and P = 0.002, respectively). Expression was observed in macrophages, foam cells, endothelial cells, and smooth muscle cells. Moreover, unstable plaques from men demonstrated greater features of plaque instability compared to unstable plaques from women, including hemorrhage, large lipid core, abundance of inflammatory cells, and fibrous cap infiltration by inflammatory cells (P &lt; 0.05 for all). Conclusion: Our preliminary findings indicate a possible association between androgens and the androgen receptor pathway and plaque instability. With further investigations, our ongoing work will unravel the underlying mechanisms, and may ultimately lead to hormone-specific therapies aimed at stabilizing plaques and reducing the incidence of stroke for men and women.

Imaging Carotid Plaque Burden in Living Mice via Hybrid Semiconducting Polymer Nanoparticles-Based Near-Infrared-II Fluorescence and Magnetic Resonance Imaging

The majority of atherothrombotic events (e.g., cerebral or myocardial infarction) often occur as a result of plaque rupture or erosion in the carotid, and thereby it is urgent to assess plaque vulnerability and predict adverse cerebrovascular events. However, the monitoring evolution from stable plaque into life-threatening high-risk plaque in the slender carotid artery is a great challenge, due to not enough spatial resolution for imaging the carotid artery based on most of reported fluorescent probes. Herein, copolymerizing with the small molecules of acceptor-donor-acceptor-donor-acceptor (A-D-A′-D-A) and the electron-donating units (D′), the screened second near-infrared (NIR-II) nanoprobe presents high quantum yield and good stability, so that it enables to image slender carotid vessel with enough spatial resolution. Encouragingly, NIR-II nanoprobe can effectively target to intraplaque macrophage, meanwhile distinguishing vulnerable plaque in carotid atherosclerosis in living mice. Moreover, the NIR-II nanoprobe can dynamically monitor the fresh bleeding spots in carotid plaque, indicating the increased risk of plaque instability. Besides, magnetic resonance imaging is integrated with NIR-II fluorescence imaging to provide contrast for subtle structure (e.g., narrow lumen and lipid pool), via incorporating ultrasmall superparamagnetic iron oxide into the NIR-II nanoprobe. Thus, such hybrid NIR-II/magnetic resonance imaging multimodal nanoprobe provides an effective tool for assessing carotid plaque burden, selecting high-risk plaque, and imaging intraplaque hemorrhage, which is promising for reducing cerebral/ myocardial infarction-associated morbidity and mortality.

Non-pustular annular psoriasis with signs of high disease activity

Background: Non-pustular annular psoriasis is a rare condition in which a type of plaque psoriasis appears with ring-like lesions and a clearer central appearance. The disease activities in psoriasis may be evaluated clinically. It is essential to provide a more meaningful approach to treatment management. Case illustration: A 33-year-old woman complained of a one-year history of multiple erythematous, scaly, and annular plaques with central clearing. Some lesions were surrounded by discrete pinpoint papules on several parts of her body. The lesions worsened during seven weeks of topical and systemic therapy. Discussion: Psoriasis is a chronic, multisystem inflammatory disease with predominantly skin and joint involvement. High disease activity or unstable psoriasis was defined as recent exacerbations showing pinpoint papules developing around established and erythematous borders of the lesions. The active severe disease may present with systemic involvement due to the production of pro-inflammatory chemokines and cytokines in the skin lesions and circulation. Conclusion: A complete clinical history and physical examination can help the clinician diagnose non- pustular annular psoriasis. Several factors may cause worsening disease activity in a patient with psoriasis. Distinguishing between stable and unstable plaque psoriasis is essential to obtain information on psoriasis pathomechanism related to systemic involvement and managing therapeutic strategies. A multidisciplinary approach must be conducted in the management of a patient with high disease activity.

Adipokines and adipocytokines in men with coronary atherosclerosis and overweight

Aim To study concentrations of adipokines and their associations with proinflammatory cytokines in overweight men with coronary atherosclerosis.Material and methods This study included 79 men aged 45-60 years with atherosclerosis who had undergone coronary endarterectomy during a coronary bypass surgery, and were overweight (body weight index (BWI), 25.0-29.9 kg /m2). Based on a histological analysis of plaques, the patients were divided into two subgroups: 43 men with stable atherosclerotic plaques and 36 men with unstable plaques in coronary arteries. The control group consisted of 40 age- and BWI-matched men without clinical manifestations of IHD. Blood concentrations of adipokines, including adiponectin, adipsin, lipocalin-2, resistin, and plasminogen 1 activator inhibitor were measured by a multiplex analysis with a MILLIPLEX MAP Human Adipokine Panel 1. Concentrations of proinflammatory cytokines, including tumor necrosis factor α (TNF- α), interleukin (IL)-1β, IL-6, and C-reactive protein (CRP) were measured by enzyme immunoassay.Results The blood concentration of lipocalin -2 was higher in patients with coronary atherosclerosis and stable or unstable atherosclerotic plaques than in the control group (p&lt;0.01). Both subgroups of men with coronary atherosclerosis were characterized by significant differences from the control group in concentrations of TNF-α (p&lt;0.05), CRP, and IL-6 (p&lt;0.01). The most significant direct correlations were found between adipokines and TNF-α, IL-6, and CRP (p&lt;0.01). Results of a logistic regression analysis showed that relative odds for the presence of significant coronary stenoses increased with increasing blood concentrations of lipocalin-2 (OR=1.005, 95 % CI: 1.002-1.008, р=0.011) and IL-6 (OR=1.582 , 95 % CI: 1.241-2.017, р=0.001).Conclusion The changes in blood concentrations of adipokines associated with higher levels of proinflammatory cytokines may represent a factor that increases the probability of clinically significant coronary stenosis in overweight men with coronary atherosclerosis.

In silico model of atherosclerosis with individual patient calibration to enable precision medicine for cardiovascular disease

ObjectiveGuidance for preventing myocardial infarction and ischemic stroke by tailoring treatment for individual patients with atherosclerosis is an unmet need. Such development may be possible with computational modeling. Given the multifactorial biology of atherosclerosis, modeling must be based on complete biological networks that capture protein-protein interactions estimated to drive disease progression. Here, we aimed to develop a clinically relevant scale model of atherosclerosis, calibrate it with individual patient data, and use it to simulate optimized pharmacotherapy for individual patients. Approach and resultsThe study used a uniquely constituted plaque proteomic dataset to create a comprehensive systems biology disease model for simulating individualized responses to pharmacotherapy. Plaque tissue was collected from 18 patients with 6735 proteins at two locations per patient. 113 pathways were identified and included in the systems biology model of endothelial cells, vascular smooth muscle cells, macrophages, lymphocytes, and the integrated intima, altogether spanning 4411 proteins, demonstrating a range of 39–96% plaque instability. After calibrating the systems biology models for individual patients, we simulated intensive lipid-lowering, anti-inflammatory, and anti-diabetic drugs. We also simulated a combination therapy. Drug response was evaluated as the degree of change in plaque stability, where an improvement was defined as a reduction of plaque instability. In patients with initially unstable lesions, simulated responses varied from high (20%, on combination therapy) to marginal improvement, whereas patients with initially stable plaques showed generally less improvement. ConclusionIn this pilot study, proteomics-based system biology modeling was shown to simulate drug response based on atherosclerotic plaque instability with a power of 90%, providing a potential strategy for improved personalized management of patients with cardiovascular disease.

Automated finite element approach to generate anatomical patient-specific biomechanical models of atherosclerotic arteries from virtual histology-intravascular ultrasound.

Despite advancements in early detection and treatment, atherosclerosis remains the leading cause of death across all cardiovascular diseases (CVD). Biomechanical analysis of atherosclerotic lesions has the potential to reveal biomechanically instable or rupture-prone regions. Treatment decisions rarely consider the biomechanics of the stenosed lesion due in-part to difficulties in obtaining this information in a clinical setting. Previous 3D FEA approaches have incompletely incorporated the complex curvature of arterial geometry, material heterogeneity, and use of patient-specific data. To address these limitations and clinical need, herein we present a user-friendly fully automated program to reconstruct and simulate the wall mechanics of patient-specific atherosclerotic coronary arteries. The program enables 3D reconstruction from patient-specific data with heterogenous tissue assignment and complex arterial curvature. Eleven arteries with coronary artery disease (CAD) underwent baseline and 6-month follow-up angiographic and virtual histology-intravascular ultrasound (VH-IVUS) imaging. VH-IVUS images were processed to remove background noise, extract VH plaque material data, and luminal and outer contours. Angiography data was used to orient the artery profiles along the 3D centerlines. The resulting surface mesh is then resampled for uniformity and tetrahedralized to generate the volumetric mesh using TetGen. A mesh convergence study revealed edge lengths between 0.04 mm and 0.2 mm produced constituent volumes that were largely unchanged, hence, to save computational resources, a value of 0.2 mm was used throughout. Materials are assigned and finite element analysis (FEA) is then performed to determine stresses and strains across the artery wall. In a representative artery, the highest average effective stress was in calcium elements with 235 kPa while necrotic elements had the lowest average stress, reaching as low as 0.79 kPa. After applying nodal smoothening, the maximum effective stress across 11 arteries remained below 288 kPa, implying biomechanically stable plaques. Indeed, all atherosclerotic plaques remained unruptured at the 6-month longitudinal follow up diagnosis. These results suggest our automated analysis may facilitate assessment of atherosclerotic plaque stability.

Atherosclerosis risk classification with computed tomography angiography: A radiologic-pathologic validation study

Background and aimsThe application of machine learning to assess plaque risk phenotypes on cardiovascular CT angiography (CTA) is an area of active investigation. Studies using accepted histologic definitions of plaque risk as ground truth for machine learning models are uncommon. The aim was to evaluate the accuracy of a machine-learning software for determining plaque risk phenotype as compared to expert pathologists (histologic ground truth). MethodsSections of atherosclerotic plaques paired with CTA were prospectively collected from patients undergoing carotid endarterectomy at two centers. Specimens were annotated for lipid-rich necrotic core, calcification, matrix, and intraplaque hemorrhage at 2 mm spacing and classified as minimal disease, stable plaque, or unstable plaque according to a modified American Heart Association histological definition. Phenotype is determined in two steps: plaque morphology is delineated according to histological tissue definitions, followed by a machine learning classifier. The performance in derivation and validation cohorts for plaque risk categorization and stenosis was compared to histologic ground truth at each matched cross-section. ResultsA total of 496 and 408 vessel cross-sections in the derivation and validation cohorts (from 30 and 23 patients, respectively). The software demonstrated excellent agreement in the validation cohort with histological ground truth plaque risk phenotypes with weighted kappa of 0.82 [0.78–0.86] and area under the receiver operating curve for correct identification of plaque type was 0.97 [0.96, 0.98], 0.95 [0.94, 0.97], 0.99 [0.99, 1.0] for unstable plaque, stable plaque, and minimal disease, respectively. Diameter stenosis correlated poorly to histologically defined plaque type; weighted kappa 0.25 in the validation cohort. ConclusionsA machine-learning software trained on histological ground-truth tissue inputs demonstrated high accuracy for identifying plaque stability phenotypes as compared to expert pathologists.

Abstract 9588: Intraplaque Myeloperoxidase Activity is a Hallmark of Vulnerable Atherosclerosis and Correlates With Clinical Outcomes

Introduction: There remains limited means by which to detect unstable atherosclerosis in patients at risk of myocardial infarction and stroke. Myeloperoxidase (MPO) is increased in unstable plaque and causally linked to plaque destabilization and rupture in pre-clinical models. We sought to assess whether MPO activity is greater in vulnerable human carotid and coronary atheroma, and how this relates to adverse cardiovascular events and non-invasive imaging parameters. Methods: Carotid endarterectomy specimens (CEA) were collected from 31 patients. Coronary trees were collected from 12 patients undergoing heart transplantation for ischemic cardiomyopathy. MPO activity was assessed through the conversion of hydroethidine added to tissue sections to the MPO-specific adduct 2-chloroethidium (2-Cl-E + ) and quantified by mass spectrometry. MPO activity was then compared with histologic determination of plaque phenotype and clinical outcomes. MPO activity was additionally assessed in high and low attenuation plaques derived by computed tomography, as well as perivascular adipose tissue (PVAT). Results: Unstable CEA had higher MPO activity when compared with stable CEA plaques (n = 26, 4.2 ± 3.1 vs. 0.2 ± 0.3 μmol/mgp; p &lt; 0.0001). Similar results were seen in coronary segments with unstable compared to stable plaque (n = 17, 0.6 ± 0.5 vs. 0.0 ± 0.0 μmol/mgp; p = 0.0006). When comparing MPO activity in CEA to clinical outcomes, asymptomatic and stroke-free patients had lower MPO activity compared to those with symptoms or ipsilateral stroke on neuroimaging (n = 12, 3.7 ± 2.1 vs. 0.1 ± 0.2 μmol/mgp; p = 0.002). CT-determined plaque attenuation did not identify plaque MPO activity (n = 30, 0.1 ± 0.1 vs. 0.2 ± 0.3 μmol/mgp; p = 0.23) and enzymatically active MPO was not found in PVAT. Conclusion: MPO is active within unstable human carotid and coronary plaques and correlates with symptomatic carotid disease and stroke. In addition, current non-invasive imaging parameters do not selectively identify plaques enriched with active MPO. As intraplaque MPO appears to be a hallmark of unstable atherosclerosis and can potentially be imaged non-invasively, further investigation into its potential utility as a diagnostic tool for high-risk atherosclerosis is warranted.

Abstract 15261: Adipor2 Sirna-Mediated Knockdown Predominantly Polarizes Towards a M1 Phenotype in THP-1 Macrophages

Introduction: Monocyte-derived macrophages (Mϕs) are the major innate immune cells in plaques, where they assume a more pro-inflammatory (M1) or anti-inflammatory (M2) Mϕ phenotype. Notably, M1 Mϕs are more abundant in unstable plaques, while M2 in stable plaques. Adiponectin receptor 1 (AdipoR1) and AdipoR2 are highly expressed in the monocyte/Mϕ lineage and largely mediate immune responses. Herein, we investigated the specific contribution of AdipoR1 and AdipoR2 on polarization towards a M1 or M2 Mϕ phenotype. Methods: siRNA-mediated knockdown of AdipoR1 and/or AdipoR2 was performed in THP-1 monocyte-derived Mϕs, and collected to perform, 1) qRT-PCR analyses on AdipoR1 and AdipoR2, and 2) flow cytometry analyses on M1 Mϕ markers: CD86, CD80, MHC-II, and M2 Mϕ markers: CD206, CD163. Results: For qRT-PCR analyses, siRNA-mediated knockdown of single AdipoR1 and AdipoR2 significantly decreased the mRNA levels of their respective receptor (p&lt;0.01, p&lt;0.0001), while the opposing receptor was unaffected. Double knockdown resulted in a significant decrease in both AdipoR1 and AdipoR2 mRNA levels (p&lt;0.001, p&lt;0.0001). For flow cytometry analyses, single AdipoR1 and double AdipoR1/R2 siRNA led to a significant decrease in ΔMFI (mean fluorescence intensity) of MHC-II (p&lt;0.01), while a significant increase was observed in single AdipoR2 siRNA (p&lt;0.01). Intracellular siRNA-mediated knockdown of AdipoR1 and/or AdipoR2 did not result in a significant loss of their cell surface expression, as confirmed via dot plots analyses. Lastly, single AdipoR1 and double AdipoR1/R2 siRNA exhibited decreased % MHC-II/CD86-positive cells (p&lt;0.01, p&lt;0.001), while single AdipoR2 siRNA increased % MHC-II/CD86-positive cells (p&lt;0.05). Conclusions: Despite intracellular siRNA-mediated knockdown of AdipoR1 and/or AdipoR2, their cell surface expression remains intact. Furthermore, single AdipoR2 siRNA was associated with an increase in M1 Mϕ population (MHC-II/CD86), which is in line with our previous evidence showing decreased AdipoR2 signalling in unstable plaques. Thus, downregulation of AdipoR2 may play a role in polarization predominantly towards a M1 phenotype in THP-1 Mϕs and hence could be mechanistically relevant in the development of unstable plaques.

Abstract 11941: Accuracy of OCT Core Labs in Determining Coronary Artery Plaque Composition

Introduction: Intravascular optical coherence tomography (OCT) provides a high-resolution representation of coronary atherosclerosis. However, the accuracy of OCT image interpretation is unknown. We present a blinded study of histologically identified OCT human plaque composition by leading international OCT core labs. Hypothesis: Human readers are unable to accurately identify all plaque compositions. Methods: Seven recognized OCT core labs (Japan, Netherlands, Switzerland, USA) participated. Each laboratory was provided 51 OCT image clips recorded from ex vivo human coronary arteries within 24 hours of death and had regions of interest processed for H&amp;E stain. Nine plaque components were identified and are listed in Results. Each OCT core lab was asked to blindly read OCT images and complete a questionnaire indicating one of nine possible plaque types. Kappa coefficient ( k ) was used ( k &lt; 0.5 poor agreement, k &gt; 0.5 high agreement) to measure intra-reader agreement; the median k is reported for each plaque component. Results: High agreement was demonstrated in identifying stable plaque including fibrous (0.93), calcium (0.83), layered plaque (1.0), and ThCFA (0.63), in contrast to unstable plaque including calcified nodule (0.50), lipid pool (0.35), macrophages/foam cells (0.35), TCFA (0.39), and necrotic core (0.22). When categories were restricted to Fibrous, Calcium, and Lipids, with Lipids expanded to include lipid pool, TCFA, and necrotic core, similar to an OCT core lab definition, k for Lipids increased to 0.61. Conclusions: Results suggest that participating OCT core labs can accurately identify combined lipid categories (lipid pool, TCFA, and necrotic core), fibrous tissue and calcium. However, accuracy is reduced when reading more sophisticated unstable plaque components. Study results emphasize the need for the development of OCT plaque composition analysis with artificial intelligence.