A definition of advanced types of atherosclerotic lesions and a histological classification of atherosclerosis. A report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association

Comparison between genetic and pharmaceutical disruption of Ldlr expression for the development of atherosclerosis

Antisense oligonucleotides (ASOs) against Ldl receptor (Ldlr-ASO) represent a promising strategy to promote hypercholesterolemic atherosclerosis in animal models without the need for complex breeding strategies. Here, we sought to characterize and contrast atherosclerosis in mice given Ldlr-ASO with those bearing genetic Ldlr deficiency. To promote atherosclerosis, male and female C57Bl6/J mice were either given weekly injections of Ldlr-ASO (5 mg/kg once per week) or genetically deficient in Ldlr (Ldlr-/-). Mice consumed either standard rodent chow or a diet high in saturated fat and sucrose with 0.15% added cholesterol for 16 weeks. While both models of Ldlr deficiency promoted hypercholesterolemia, Ldlr-/- mice exhibited nearly 2-fold higher cholesterol levels than Ldlr-ASO mice, reflected by increased VLDL and LDL levels. Consistent with this, the en face atherosclerotic lesion area was 3-fold and 3.6-fold greater in male and female mice with genetic Ldlr deficiency, respectively, as compared with the modest atherosclerosis observed following Ldlr-ASO treatment. Aortic sinus lesion sizes, fibrosis, smooth muscle actin, and necrotic core areas were also larger in Ldlr-/- mice, suggesting a more advanced phenotype. Despite a more modest effect on hypercholesterolemia, Ldlr-ASO induced greater hepatic inflammatory gene expression, macrophage accumulation, and histological lobular inflammation than was observed in Ldlr-/- mice. We conclude Ldlr-ASO is a promising tool for the generation of complex rodent models with which to study atherosclerosis but does not promote comparable levels of hypercholesterolemia or atherosclerosis as Ldlr-/- mice and increases hepatic inflammation. Thus, genetic Ldlr deficiency may be a superior model, depending on the proposed use.

Atherosclerotic Lesion of the Carotid Artery in Indonesian Cynomolgus Monkeys Receiving a Locally Sourced Atherogenic Diet

The atherosclerotic lesion is a principal hallmark of atherosclerotic animal models. This study aimed to assess lesions of the carotid artery in Indonesian cynomolgus monkeys exposed to an IPB-1 atherogenic diet. A total of 20 adult male cynomolgus monkeys received the local IPB-1 diet for two years. Blood lipid profiles, morphology, and carotid ultrasound of monkeys were measured. Nine of them were euthanized to confirm atherosclerotic lesions. Common carotid arteries (CCA) and carotid bifurcation (BIF) samples were collected and stained using Verhoef-van Giessen and CD68 immunohistochemistry. The results reveal the presence of severe atherosclerosis plaques in six out of nine animals (66.7%) corresponding to intermediately and hyper-responsive groups. The hyper-responsive group displayed the highest response in the developing intimal area (IA) at the CCA (0.821 mm²), whereas the hyporesponsive group had the smallest IA (0.045 mm²) (p = 0.0001). At the BIF, the hyporesponsive group showed the smallest IA (p = 0.001), but there was no difference between the intermediately and hyper-responsive groups (p = 0.312). The macrophage marker CD68 was also expressed on the cartotid of the intermediately and hyper-responsive groups. These results indicate that severe atherosclerotic lesions with high infiltration of macrophages were formed in the carotid arteries of intermediately and hyper-responsive Indonesian cynomolgus monkeys fed with the local atherogenic diet IPB-1 over two years, thus confirming atherosclerosis in a nonhuman primate model.

Rapid Regression of Carotid Artery Stenosis Shortly after Intensive Medical Therapy

Carotid artery stenosis (CAS) is mainly caused by atherosclerosis. Intensive medical therapy is effective in preventing stroke in CAS. To date, there has been no published report of rapid regression of CAS. A woman with untreated hyperlipidemia visited our emergency room with left hemiparesis. She exhibited facial palsy, left hemiparesis, and dysarthria immediately after the visit. Brain magnetic resonance (MR) diffusion-weighted imaging confirmed acute infarction in the right middle cerebral artery (MCA) territory due to severe stenosis of the right internal carotid artery (ICA), which was revealed by MR angiography and carotid duplex ultrasonography. The patient started intensive statin therapy and dual antiplatelet agent therapy. Carotid artery stenting was not performed until hospitalization day 16 due to pleural effusion. On day 16, digital subtraction angiography was performed, and spontaneous regression of severe stenosis was observed. Only mild stenosis with ulcerative plaque was evident. The rapid CAS regression in this case may be caused by M2 macrophage polarization as a result of intensive statin therapy. This rapid regression may also result from reduced foam cell formation by statin and aspirin and thereby increased endogenous thrombolysis. Our patient demonstrated the efficacy of short-term intensive statin and aspirin therapy on atherosclerosis with untreated hyperlipidemia.

Involvement of enhanced expression of classical complement C1q in atherosclerosis progression and plaque instability: C1q as an indicator of clinical outcome

Activation of the classical complement pathway plays a major role in regulating atherosclerosis progression, and it is believed to have both proatherogenic and atheroprotective effects. This study focused on C1q, the first protein in the classical pathway, and examined its potentialities of plaque progression and instability and its relationship with clinical outcomes. To assess the localization and quantity of C1q expression in various stages of atherosclerosis, immunohistochemistry, western blotting, and real-time polymerase chain reaction (PCR) were performed using abdominal aortas from eight autopsy cases. C1q immunoreactivity in relation to plaque instability and clinical outcomes was also examined using directional coronary atherectomy (DCA) samples from 19 patients with acute coronary syndromes (ACS) and 18 patients with stable angina pectoris (SAP) and coronary aspirated specimens from 38 patients with acute myocardial infarction. C1q immunoreactivity was localized in the extracellular matrix, necrotic cores, macrophages and smooth muscle cells in atherosclerotic lesions. Western blotting and real-time PCR illustrated that C1q protein and mRNA expression was significantly higher in advanced lesions than in early lesions. Immunohistochemical analysis using DCA specimens revealed that C1q expression was significantly higher in ACS plaques than in SAP plaques. Finally, immunohistochemical analysis using thrombus aspiration specimens demonstrated that histopathological C1q in aspirated coronary materials could be an indicator of poor medical condition. Our results indicated that C1q is significantly involved in atherosclerosis progression and plaque instability, and it could be considered as one of the indicators of cardiovascular outcomes.

The Effects of Porphyromonas gingivalis on Atherosclerosis-Related Cells

Atherosclerosis (AS), one of the most common types of cardiovascular disease, has initially been attributed to the accumulation of fats and fibrous materials. However, more and more researchers regarded it as a chronic inflammatory disease nowadays. Infective disease, such as periodontitis, is related to the risk of atherosclerosis. Porphyromonas gingivalis (P. gingivalis), one of the most common bacteria in stomatology, is usually discovered in atherosclerotic plaque in patients. Furthermore, it was reported that P. gingivalis can promote the progression of atherosclerosis. Elucidating the underlying mechanisms of P. gingivalis in atherosclerosis attracted attention, which is thought to be crucial to the therapy of atherosclerosis. Nevertheless, the pathogenesis of atherosclerosis is much complicated, and many kinds of cells participate in it. By summarizing existing studies, we find that P. gingivalis can influence the function of many cells in atherosclerosis. It can induce the dysfunction of endothelium, promote the formation of foam cells as well as the proliferation and calcification of vascular smooth muscle cells, and lead to the imbalance of regulatory T cells (Tregs) and T helper (Th) cells, ultimately promoting the occurrence and development of atherosclerosis. This article summarizes the specific mechanism of atherosclerosis caused by P. gingivalis. It sorts out the interaction between P. gingivalis and AS-related cells, which provides a new perspective for us to prevent or slow down the occurrence and development of AS by inhibiting periodontal pathogens.

Image-based biomechanical modeling for coronary atherosclerotic plaque progression and vulnerability prediction

Atherosclerotic plaque progression and rupture play an important role in cardiovascular disease development and the final drastic events such as heart attack and stroke. Medical imaging and image-based computational modeling methods advanced considerably in recent years to quantify plaque morphology and biomechanical conditions and gain a better understanding of plaque evolution and rupture process. This article first briefly reviewed clinical imaging techniques for coronary thin-cap fibroatheroma (TCFA) plaques used in image-based computational modeling. This was followed by a summary of different types of biomechanical models for coronary plaques. Plaque progression and vulnerability prediction studies based on image-based computational modeling were reviewed and compared. Much progress has been made and a reasonable high prediction accuracy has been achieved. However, there are still some inconsistencies in existing literature on the impact of biomechanical and morphological factors on future plaque behavior, and it is very difficult to perform direct comparison analysis as differences like image modality, biomechanical factors selection, predictive models, and progression/vulnerability measures exist among these studies. Encouraging data and model sharing across the research community would partially resolve these differences, and possibly lead to clearer assertive conclusions. In vivo image-based computational modeling could be used as a powerful tool for quantitative assessment of coronary plaque vulnerability for potential clinical applications.

Physical activity and carotid atherosclerosis risk reduction in population with high risk for cardiovascular diseases: a cross-sectional study

Background

Decreased physical activity had been reported to be a common causal and modifiable risk factor for major vascular events. However, the relationship of physical activity and sedentary leisure time with carotid atherosclerosis in population with high risk for cardiovascular diseases (CVDs) is still inconclusive. We aimed to evaluate the association of physical activity and sedentary leisure time with the risk of carotid atherosclerosis, and investigate any possible effect modifiers in population with high risk for CVDs.

Methods

The study population was drawn from the China Patient-Centered Evaluative Assessment of Cardiac Events (PEACE) Million Persons Project-Jiangsu project, which is a population-based screening project that included permanent residents aged 35-75 years from 6 surveillance cities in Jiangsu Province. Linear regression models were used to evaluate the association of physical activity and sedentary leisure time with carotid intima-media thickness (CIMT). The risks of abnormal carotid artery and carotid plaque (CP) were estimated by odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression.

Results

Overall, a total of 10,920 participants were enrolled in the final analysis. There was a significant inverse association of physical activity level with CIMT (per SD increase: β=-0.0103; 95%CI: -0.0154, -0.0053). The risk of abnormal carotid artery and CP decreased significantly with the increase of physical activity level (per SD increase: OR=0.908, 95%CI: 0.869-0.948; OR=0.900, 95%CI: 0.857-0.945, respectively). When physical activity level was categorized as quartiles, a significantly lower risk of abnormal carotid artery and CP was found in quartiles 2-4 with quartile 1 as reference (P<0.05 for all). Furthermore, the inverse association were stronger in participants with age ≥60 years (vs. <60 years, P_interaction<0.001 for both). However, there were no significant association of sedentary leisure time with CIMT, abnormal carotid artery and CP.

Conclusions

In population with high risk for CVDs, physical activity was inversely associated with CIMT, abnormal carotid artery and CP, particularly among the elders. Sedentary leisure time was not associated with them. These results suggested that physical activity is important for carotid vascular health, and perhaps especially in elder population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12582-6.

Enterobacter cloacae aggravates metabolic disease by inducing inflammation and lipid accumulation

It is well known that gut microbiota imbalance can promote the development of metabolic disease. Enterobacter cloacae (E. cloacae) is a kind of opportunistic pathogen in the intestine. Therefore, we hypothesized that E. cloacae accelerated the development of metabolic disease. To answer this question, we used E. cloacae to induce disease in guinea pigs. We used H&E staining to detect the pathological changes of liver and aorta and used Oil Red O staining to evaluate the lipid accumulation in the liver. And that we used a kit to detect AST content and used Western blot to detect protein levels in the liver. We found that E. cloacae could induce liver pathological changes and lipid accumulation as well as aortic wall pathological changes in guinea pigs. And E. cloacae increased the liver index to 5.94% and the serum AST level to 41.93 U/L. Importantly, E. cloacae activated liver high mobility group protein (HMGB1)/toll-like receptor 4 (TLR4)/myeloiddifferentiationfactor88 (MYD88)/nuclear factor-kappa B (NF-κB) signal and sterol regulatory element-binding protein 1c (SREBP-1c) and inhibited AMP-activated protein kinase (AMPK). We conclude that E. cloacae promote nonalcoholic fatty liver disease (NAFLD) by inducing inflammation and lipid accumulation, and E. cloacae also promote atherosclerosis. These findings are important for study on the pathogenesis and drug screening of NAFLD and atherosclerosis.

Predictive mouse model reflects distinct stages of human atheroma in a single carotid artery

Identification of patients with high-risk asymptomatic atherosclerotic plaques remains an elusive but essential step in preventing stroke. However, there is a lack of animal model that provides a reproducible method to predict where, when and what types of plaque formation, which fulfils the American Heart Association (AHA) histological classification of human plaques. We have developed a predictive mouse model that reflects different stages of human plaques in a single carotid artery by means of shear-stress modifying cuff. Validated with over 30000 histological sections, the model generates a specific pattern of plaques with different risk levels along the same artery depending on their position relative to the cuff. The further upstream of the cuff-implanted artery, the lower the magnitude of shear stress, the more unstable the plaques of higher grade according to AHA classification; with characteristics including greater degree of vascular remodeling, plaque size, plaque vulnerability and inflammation, resulting in higher risk plaques. By weeks 20 and 30, this model achieved 80% and near 100% accuracy respectively, in predicting precisely where, when and what stages/AHA types of plaques develop along the same carotid artery. This model can generate clinically-relevant plaques with varying phenotypes fulfilling AHA classification and risk levels, in specific locations of the single artery with near 100% accuracy of prediction. The model offers a promising tool for development of diagnostic tools to target high-risk plaques, increasing accuracy in predicting which individual patients may require surgical intervention to prevent stroke, paving the way for personalized management of carotid atherosclerotic disease.

Inflammation as a mechanism and therapeutic target in peripheral artery disease

Peripheral artery disease is one of three major clinical manifestations of atherosclerosis, the other two being coronary artery and cerebrovascular disease. Despite progress in surgery, antithrombotic therapy and therapies that modify conventional risk factors (lipid-, blood pressure-, and glucose-lowering interventions), patients with peripheral artery disease have unacceptably high risk of vascular complications. Additional strategies to reduce this residual risk are needed. The accumulated evidence that inflammation plays an important role in the pathogenesis of atherosclerosis has spurred recent efforts to evaluate anti-inflammatory agents as an additional therapeutic approach for atherothrombosis prevention and treatment. In this review, we examine the evidence supporting the role of inflammation in atherosclerosis, review recent trials evaluating anti-inflammatory approaches to reduce cardiovascular complications, and offer insights into the opportunities for novel anti-inflammatory strategies to reduce the burden of cardiovascular and limb complications in patients with peripheral artery disease.

Atherosclerosis: Known and unknown

Atherosclerotic disease, such as myocardial infarction and stroke, is the number one killer worldwide. Atherosclerosis is considered to be caused by multiple factors, including genetic and environmental factors. In humans, it takes several decades until the clinical complications develop. There are many known risk factors for atherosclerosis, including hypercholesterolemia, hypertension, diabetes and smoking, which are involved in the pathogenesis of atherosclerosis; however, it is generally believed that atherosclerosis is vascular chronic inflammation initiated by interactions of these risk factors and arterial wall cells. In the past 30 years, the molecular mechanisms underlying the pathogenesis of atherosclerosis have been investigated extensively using genetically modified animals, and lipid-reducing drugs, such as statins, have been demonstrated as the most effective for the prevention and treatment of atherosclerosis. However, despite this progress, questions regarding the pathogenesis of atherosclerosis remain and there is a need to develop new animal models and novel therapeutics to treat patients who cannot be effectively treated by statins. In this review, we will focus on two topics of atherosclerosis, "pathology" and "pathogenesis," and discuss unanswered questions.

Phage Display Preparation of Specific Polypeptides in Atherosclerotic Foam Cells

Atherosclerosis and related complications are the most common causes of death in modern societies. Macrophage-derived foam cells play critical roles in the initiation and progression of atherosclerosis. Effective, rapid, and instrument-independent detection in the early stage of chronic atherosclerosis progression could provide an opportunity for early intervention and treatment. Therefore, as a starting point, in this study, we aimed to isolate and prepare foam cell-specific polypeptides using a phage display platform. The six target polypeptides, which were acquired in this study, were evaluated by ELISA and showed strong specificity with foam cells. Streptavidin coupled quantum dots (QDs) were used as fluorescence developing agents, and images of biotin-modified polypeptides specifically binding with foam cells were clearly observed. The polypeptides obtained in this study could lay the foundation for developing a rapid detection kit for early atherosclerosis lesions and could provide new materials for research on the mechanisms of foam cell formation and the development of blocking drugs.

Coronary Atherosclerotic Plaque Regression: JACC State-of-the-Art Review

Over the last 3 decades there have been substantial improvements in treatments aimed at reducing cardiovascular (CV) events. As these treatments have been developed, there have been parallel improvements in coronary imaging modalities that can assess plaque volumes and composition, using both invasive and noninvasive techniques. Plaque progression can be seen to precede CV events, and therefore, many studies have longitudinally assessed changes in plaque characteristics in response to various treatments, aiming to demonstrate plaque regression and improvements in high-risk features, with the rationale being that this will reduce CV events. In the past, decisions surrounding treatments for atherosclerosis have been informed by population-based risk scores for initiation in primary prevention and low-density lipoprotein cholesterol levels for titration in secondary prevention. If outcome data linking plaque regression to reduced CV events emerge, it may become possible to directly image plaque treatment response to guide management decisions.

Immune system and atherosclerosis: Hostile or friendly relationship

Coronary artery disease has remained a major health challenge despite enormous progress in prevention, diagnosis, and treatment strategies. Formation of atherosclerotic plaque is a chronic process that is developmentally influenced by intrinsic and extrinsic determinants. Inflammation triggers atherosclerosis, and the fundamental element of inflammation is the immune system. The immune system involves in the atherosclerosis process by a variety of immune cells and a cocktail of mediators. It is believed that almost all main components of this system possess a profound contribution to the atherosclerosis. However, they play contradictory roles, either protective or progressive, in different stages of atherosclerosis progression. It is evident that monocytes are the first immune cells appeared in the atherosclerotic lesion. With the plaque growth, other types of the immune cells such as mast cells, and T lymphocytes are gradually involved. Each cell releases several cytokines which cause the recruitment of other immune cells to the lesion site. This is followed by affecting the expression of other cytokines as well as altering certain signaling pathways. All in all, a mix of intertwined interactions determine the final outcome in terms of mild or severe manifestations, either clinical or subclinical. Therefore, it is of utmost importance to precisely understand the kind and degree of contribution which is made by each immune component in order to stop the growing burden of cardiovascular morbidity and mortality. In this review, we present a comprehensive appraisal on the role of immune cells in the atherosclerosis initiation and development.

Carotid atherosclerotic disease: A systematic review of pathogenesis and management

Carotid stenosis is an important contributor to ischemic stroke risk with resultant significant impact on neurological disability and death in adults and with worldwide implications. Management of carotid stenosis is impacted by whether there are associated symptoms along with the degree of stenosis. Understanding of the pathogenesis of carotid atherosclerosis or stenosis is important in management of carotid stenosis. Atherosclerotic plaque formation is a chronic insidious process with a number of potential contributors to the formation of such a plaque. The definition of atherosclerosis is not simply limited to abnormal deposition of lipid but also includes a chronic, complex, inflammatory process. Molecularly, in atherosclerosis, there is decreasing nitric oxide (NO) bioavailability, activity and/or expression of endothelial NO synthase, or increasing degradation of NO secondary to enhanced superoxide production. These above changes cause endothelial dysfunction leading to formation of foam cell followed by formation on lipid plaque. After lipid plaque formation, stable or unstable atherosclerotic plaque is formed depending on the calcium deposition over the lipid plaque. It continues to be clearly established that carotid intervention for symptomatic high-grade carotid stenosis is best managed with intervention either by carotid endarterectomy or carotid stenting. However, asymptomatic carotid stenosis is the subject of considerable controversy in terms of optimal management. This review of carotid atherosclerosis is an attempt to incorporate the information provided by more recent studies on pathogenesis and management which may help in the decision-making process for optimal management for protection against stroke.

Identification of Symptomatic Carotid Artery Plaque: A Three-Item Scale Combined Angiography With Optical Coherence Tomography

Introduction: Symptomatic carotid disease conveys a high risk of recurrent stroke. Plaque morphology and specific plaque characteristics are associated with the risk of stroke. This study aimed to evaluate the detailed plaque features by optical coherence tomography (OCT) and develop a simple scale combining clinical indicators, digital subtraction angiography (DSA), and OCT imaging markers to identify symptomatic carotid plaque. Methods: Carotid plaques from consecutive patients who underwent carotid OCT imaging between June 2017 and June 2021 were evaluated. Clinical characteristics, DSA, and OCT data were compared between the symptomatic and asymptomatic groups. Logistic regression was performed to identify the factors associated with symptomatic carotid plaque and to develop a scale. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the scale. Results: A total of 90 carotid plaques from 90 patients were included (symptomatic 35.6%, asymptomatic 64.4%). Three main factors were found to be associated with symptomatic carotid plaque: high-density lipoprotein cholesterol (HDL-C) <0.925 mmol/L (OR, 4.708; 95% CI, 1.640 to 13.517; P = 0.004), irregular plaque (OR, 4.017; 95% CI, 1.250 to 12.910; P = 0.020), and white thrombus (OR, 4.594; 95% CI, 1.141 to 18.487; P = 0.032). The corresponding score of three items produced a scale with good discrimination (AUC, 0.768; 95% CI, 0.665 to 0.871). The optimal cutoff value of the scale was 1.5 points with 59.4% sensitivity and 84.5% specificity. Conclusion: The three-item scale comprising HDL-C <0.925 mmol/L, angiographical irregular plaque, and white thrombus detected by OCT may provide information to identify symptomatic carotid plaque. Further large-scale studies are required to validate whether the symptomatic carotid plaque scale is clinically valuable in recognizing carotid atherosclerosis in the early stages.

Loss of myeloid cell-specific SIRPα, but not CD47, attenuates inflammation and suppresses atherosclerosis

AIMS

Inhibitors of the anti-phagocytic CD47-SIRPα immune checkpoint are currently in clinical development for a variety of haematological and solid tumours. Application of immune checkpoint inhibitors to the cardiovascular field is limited by the lack of preclinical studies using genetic models of CD47 and SIRPα inhibition. In this study, we comprehensively analysed the effects of global and cell-specific SIRPα and CD47 deletion on atherosclerosis development.

METHODS AND RESULTS

Here, we show that both SIRPα and CD47 expression are increased in human atherosclerotic arteries and primarily co-localize to CD68+ areas in the plaque region. Hypercholesterolaemic mice homozygous for a Sirpa mutant lacking the signalling cytoplasmic region (Sirpamut/mut) and myeloid cell-specific Sirpa-knockout mice are protected from atherosclerosis. Further, global Cd47-/- mice are protected from atherosclerosis but myeloid cell-specific deletion of Cd47 increased atherosclerosis development. Using a combination of techniques, we show that loss of SIRPα signalling in macrophages stimulates efferocytosis, reduces cholesterol accumulation, promotes lipid efflux, and attenuates oxidized LDL-induced inflammation in vitro and induces M2 macrophage phenotype and inhibits necrotic core formation in the arterial wall in vivo. Conversely, loss of myeloid cell CD47 inhibited efferocytosis, impaired cholesterol efflux, augmented cellular inflammation, stimulated M1 polarization, and failed to decrease necrotic core area in atherosclerotic vessels. Finally, comprehensive blood cell analysis demonstrated lower haemoglobin and erythrocyte levels in Cd47-/- mice compared with wild-type and Sirpamut/mut mice.

CONCLUSION

Taken together, these findings identify SIRPα as a potential target in atherosclerosis and suggest the importance of cell-specific CD47 inhibition as a future therapeutic strategy.

Lipopolysaccharide and tyloxapol accelerate the development of atherosclerosis in mice

The occurrence of atherosclerosis is closely related to inflammation and lipid metabolism disorder. It has been found that lipopolysaccharide (LPS) could induce inflammation, and tyloxapol (Ty) could induce hyperlipidemia. However, the effects of LPS and Ty on the development and mechanism of atherosclerosis have not been investigated thoroughly. To answer this question, we used assay kits to detect total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) content to evaluate dyslipidemia. We used hematoxylin and eosin staining to evaluate the pathological structure of the aorta and liver, and then used Oil Red O staining to access lipid accumulation in the aortic wall. Subsequently, we used the alanine transaminase (ALT) kit to examine the liver injury. Finally, we used the Western blot experiment to measure proteins that regulate lipid metabolism. We found that the LPS + Ty group could increase the levels of TC, TG, and LDL in the serum and promote lipid accumulation in the aortic wall in mice. Moreover, our study showed that the LPS + Ty group induced pathological changes in hepatocytes and increased ALT content in mice. Significantly, we found that the LPS + Ty group could activate acetyl-CoA carboxylase, sterol regulatory element-binding protein-1c, and inhibit peroxisome proliferator-activated receptors α in mice. Therefore, we suppose that LPS and Ty aggravated the development of atherosclerosis by promoting hyperlipidemia and the disorder of lipid metabolism in mice. These findings are significant for the study of the pathogenesis of atherosclerosis and the selection of animal models.

Reconnection of fragmented parts of coronary arteries using local geometric features in X-ray angiography images

The segmentation of coronary arteries in X-ray images is essential for image-based guiding procedures and the diagnosis of cardiovascular disease. However, owing to the complex and thin structures of the coronary arteries, it is challenging to accurately segment arteries in X-ray images using only a single neural network model. Consequently, coronary artery images obtained by segmentation with a single model are often fragmented, with parts of the arteries missing. Sophisticated post-processing is then required to identify and reconnect the fragmented regions. In this paper, we propose a method to reconstruct the missing regions of coronary arteries using X-ray angiography images.

METHOD

We apply an independent convolutional neural network model considering local details, as well as a local geometric prior, for reconnecting the disconnected fragments. We implemented and compared the proposed method with several convolutional neural networks with customized encoding backbones as baseline models.

RESULTS

When integrated with our method, existing models improved considerably in terms of similarity with ground truth, with a mean increase of 0.330 of the Dice similarity coefficient in local regions of disconnected arteries. The method is efficient and is able to recover missing fragments in a short number of iterations.

CONCLUSION AND SIGNIFICANCE

Owing to the restoration of missing fragments of coronary arteries, the proposed method enables a significant enhancement of clinical impact. The method is general and can simply be integrated into other existing methods for coronary artery segmentation.

Pro-Inflammatory Serum Amyloid a Stimulates Renal Dysfunction and Enhances Atherosclerosis in Apo E-Deficient Mice

Acute serum amyloid A (SAA) is an apolipoprotein that mediates pro-inflammatory and pro-atherogenic pathways. SAA-mediated signalling is diverse and includes canonical and acute immunoregulatory pathways in a range of cell types and organs. This study aimed to further elucidate the roles for SAA in the pathogenesis of vascular and renal dysfunction. Two groups of male ApoE-deficient mice were administered SAA (100 µL, 120 µg/mL) or vehicle control (100 µL PBS) and monitored for 4 or 16 weeks after SAA treatment; tissue was harvested for biochemical and histological analyses at each time point. Under these conditions, SAA administration induced crosstalk between NF-κB and Nrf2 transcriptional factors, leading to downstream induction of pro-inflammatory mediators and antioxidant response elements 4 weeks after SAA administration, respectively. SAA treatment stimulated an upregulation of renal IFN-γ with a concomitant increase in renal levels of p38 MAPK and matrix metalloproteinase (MMP) activities, which is linked to tissue fibrosis. In the kidney of SAA-treated mice, the immunolocalisation of inducible nitric oxide synthase (iNOS) was markedly increased, and this was localised to the parietal epithelial cells lining Bowman’s space within glomeruli, which led to progressive renal fibrosis. Assessment of aortic root lesion at the study endpoint revealed accelerated atherosclerosis formation; animals treated with SAA also showed evidence of a thinned fibrous cap as judged by diffuse collagen staining. Together, this suggests that SAA elicits early renal dysfunction through promoting the IFN-γ-iNOS-p38 MAPK axis that manifests as the fibrosis of renal tissue and enhanced cardiovascular disease.

Contribution of Endoplasmic Reticulum Stress to the Clinical Instability of Carotid Plaques in Human Carotid Stenosis

Endoplasmic reticulum (ER) stress is an important process during the progression of atherosclerosis. The aim of this study was to elucidate the association of ER stress and clinical instability of carotid plaque. One hundred ninety-three patients with carotid stenosis undergoing carotid endarterectomies (CEAs) were enrolled. We classified the patients into 3 groups: the asymptomatic, symptomatic, and cTIA (crescendo transient ischemic attack)/SIE (stroke in evolution) groups. Immunohistological staining was performed to assess ER stress and apoptosis. The correlation between ER stress marker expression and clinical instability was analyzed by Tukey-Kramer test and ordinal logistic regression. From the 193 CEAs, 24 asymptomatic plaques and 24 symptomatic plaques were randomly selected, and all 7 plaques in the cTIA/SIE group were selected. Glycophorin A staining demonstrated significant correlation between intraplaque hemorrhage and clinical instability (odds ratio [OR], 1.27; 95%CI, 1.14-1.41). The expression of ER stress markers (glucose-regulated protein 78 [GRP78] and C/EBP homologous protein [CHOP]) exhibited a significant correlation with clinical instability (GRP78: OR, 1.25; 95%CI, 1.14-1.38, CHOP: OR, 1.39; 95%CI, 1.16-1.66). Double-label immunofluorescence demonstrated ER stress markers were detected in CD68-positive cells and smooth muscle actin (SMA)-positive cells. The coexpression of the ER stress markers exhibited a significant correlation with clinical instability (CD68/GRP78: OR, 1.13; 95%CI, 1.05-1.20, CD68/CHOP: OR, 1.092; 95%CI, 1.04-1.14, SMA/CHOP: OR, 1.082; 95%CI, 1.04-1.13). However, the colocalization of CHOP and cleaved caspase-3 (apoptosis marker) did not correlate with clinical instability. These findings indicated that the ER stress pathway may be a potential therapeutic target in the prevention of stroke.

Exploring arterial tissue microstructural organization using non-Gaussian diffusion magnetic resonance schemes

The purpose of this study was to characterize the alterations in microstructural organization of arterial tissue using higher-order diffusion magnetic resonance schemes. Three porcine carotid artery models namely; native, collagenase treated and decellularized, were used to estimate the contribution of collagen and smooth muscle cells (SMC) on diffusion signal attenuation using gaussian and non-gaussian schemes. The samples were imaged in a 7 T preclinical scanner. High spatial and angular resolution diffusion weighted images (DWIs) were acquired using two multi-shell (max b-value = 3000 s/mm²) acquisition protocols. The processed DWIs were fitted using monoexponential, stretched-exponential, kurtosis and bi-exponential schemes. Directionally variant and invariant microstructural parametric maps of the three artery models were obtained from the diffusion schemes. The parametric maps were used to assess the sensitivity of each diffusion scheme to collagen and SMC composition in arterial microstructural environment. The inter-model comparison showed significant differences across the considered models. The bi-exponential scheme based slow diffusion compartment (Ds) was highest in the absence of collagen, compared to native and decellularized microenvironments. In intra-model comparison, kurtosis along the radial direction was the highest. Overall, the results of this study demonstrate the efficacy of higher order dMRI schemes in mapping constituent specific alterations in arterial microstructure.

CT angiographic biomarkers help identify vulnerable carotid artery plaque

OBJECTIVE

Current risk assessment for patients with carotid atherosclerosis relies primarily on measuring the degree of stenosis. More reliable risk-stratification could improve patient selection for targeted treatment. We developed and validated a model to predict major adverse neurological events (MANE; stroke, transient ischemic attack, and amaurosis fugax) incorporating a combination of plaque morphology, patient demographics, and patient clinical information.

METHODS

We enrolled 221 patients with asymptomatic carotid stenosis of any severity who had CT angiography at baseline and at least 6 months later. Images were analyzed for carotid plaque morphology (plaque geometry and tissue composition). Data were partitioned (training and validation cohorts). 190 patients had complete records and were advanced to analysis. The training cohort was used to develop the best model for predicting MANE, incorporating patient and plaque features. First, single-variable correlation and unsupervised clustering were performed. Next, several multi-variable models were implemented for the response variable of MANE. The best model was selected by optimizing area under the receiver operating characteristic curve (AUC, ROC) and Kappa. The model was validated on the sequestered data to demonstrate generalizability.

RESULTS

Sixty-two patients suffered a MANE on follow-up. Unsupervised clustering of patient and plaque features identified single-variable predictors of MANE. Multi-variable predictive modeling showed that a combination of plaque features at baseline (matrix, intra-plaque hemorrhage (IPH), wall thickness, plaque burden) with clinical features (age, BMI, lipid levels) best predicted MANE (AUC 0.79), while percent diameter stenosis performed worst (AUC 0.55). The strongest single variable in discriminating between patients with and without events was IPH, and the most predictive model was produced when IPH was considered together with wall remodeling. The selected model also performed well on the validation dataset (AUC of 0.64) and maintained superiority over percent diameter stenosis (AUC of 0.49).

CONCLUSIONS

A composite of plaque geometry, plaque tissue composition, patient demographics, and clinical information predicts MANE better than the traditionally utilized degree of stenosis alone in carotid atherosclerosis. Implementing this predictive model in the clinical setting can help identify patients at high-risk for major adverse neurological events.

Quantifying Patient-Specific in vivo Coronary Plaque Material Properties for Accurate Stress/Strain Calculations: An IVUS-Based Multi-Patient Study

Introduction: Mechanical forces are closely associated with plaque progression and rupture. Precise quantifications of biomechanical conditions using in vivo image-based computational models depend heavily on the accurate estimation of patient-specific plaque mechanical properties. Currently, mechanical experiments are commonly performed on ex vivo cardiovascular tissues to determine plaque material properties. Patient-specific in vivo coronary material properties are scarce in the existing literature.

Methods:In vivo Cine intravascular ultrasound and virtual histology intravascular ultrasound (IVUS) slices were acquired at 20 plaque sites from 13 patients. A three-dimensional thin-slice structure-only model was constructed for each slice to obtain patient-specific in vivo material parameter values following an iterative scheme. Effective Young's modulus (YM) was calculated to indicate plaque stiffness for easy comparison purposes. IVUS-based 3D thin-slice models using in vivo and ex vivo material properties were constructed to investigate their impacts on plaque wall stress/strain (PWS/PWSn) calculations.

Results: The average YM values in the axial and circumferential directions for the 20 plaque slices were 599.5 and 1,042.8 kPa, respectively, 36.1% lower than those from published ex vivo data. The YM values in the circumferential direction of the softest and stiffest plaques were 103.4 and 2,317.3 kPa, respectively. The relative difference of mean PWSn on lumen using the in vivo and ex vivo material properties could be as high as 431%, while the relative difference of mean PWS was much lower, about 3.07% on average.

Conclusion: There is a large inter-patient and intra-patient variability in the in vivo plaque material properties. In vivo material properties have a great impact on plaque stress/strain calculations. In vivo plaque material properties have a greater impact on strain calculations. Large-scale-patient studies are needed to further verify our findings.

Long Noncoding RNA MIAT Controls Advanced Atherosclerotic Lesion Formation and Plaque Destabilization

Supplemental Digital Content is available in the text.

Long noncoding RNAs (lncRNAs) are important regulators of biological processes involved in vascular tissue homeostasis and disease development. The present study assessed the functional contribution of the lncRNA myocardial infarction-associated transcript (MIAT) to atherosclerosis and carotid artery disease.

Silencing of circARHGAP12 inhibits the progression of atherosclerosis via miR-630/EZH2/TIMP2 signal axis

Atherosclerosis (AS) is a common disease that seriously threatens human health. So far, the pathogenesis of AS has not been fully understood. This project investigates the effects of circARHGAP12 on AS and its regulatory mechanism. ApoE^-/- knockout mice (ApoE) were adopted and reared with a high-fat diet to construct an AS model. Lentivirus was established to knock down the expression of circARHGAP12 in mice. After 12 weeks, the aorta was removed and the expression of circARHGAP12 was detected. Vascular oil red O staining was used to detect the degree of AS. The expression of inflammatory factors was detected by ELISA. Aortic smooth muscle cells (MASMCs) were cultured to evaluate the effects of circARHGAP12 on the phenotype of MASMCs. RNA pull-down and luciferase assay were used to verify the downstream target genes of circARHGAP12. In addition, the effects of circARHGAP12 on MASMCs proliferation and migration were detected by MTT and transwell assay. Compared with the normal group, the expression of circARHGAP12 in the MASMCs under ox-LDL treatment was elevated, and circARHGAP12 silencing could inhibit AS in vitro and in vivo. The results of the mechanism study showed that circARHGAP12 can directly bind with miR-630. In addition, miR-630 can also target EZH2 to modulate the transcription of TIMP2 and to influence the migration of MASMCs. circARHGAP12 is upregulated in AS. CircARHGAP12 knockdown can inhibit the progression of AS. This study expands on the role of circRNA in AS and provides potential targets for the treatment of AS.

Endothelial Yin Yang 1 Phosphorylation at S118 Induces Atherosclerosis Under Flow

Rationale: Disturbed flow occurring in arterial branches and curvatures induces vascular endothelial cell (EC) dysfunction and atherosclerosis. We postulated that disturbed flow plays important roles in modulating phosphoprotein expression profiles to regulate endothelial functions and atherogenesis. Objective: The goal of this study is to discover novel site-specific phosphorylation alterations induced by disturbed flow in ECs to contribute to atherosclerosis. Methods and Results: Quantitative phosphoproteomics analysis of ECs exposed to disturbed flow with low and oscillatory shear stress (OS, 0.5plusminus4 dynes/cm²) vs. pulsatile flow with high shear stress (PS, 124plusminus dynes/cm²) revealed that OS induces serine (S)118 phosphorylation of Yin Yang 1 (phospho-YY1^S118) in ECs. Elevated phospho-YY1^S118 level in ECs was further confirmed to be present in the disturbed flow regions in experimental animals and human atherosclerotic arteries. This disturbed flow-induced EC phospho-YY1^S118 is mediated by casein kinase 2α (CK2α) through its direct interaction with YY1. Yeast two-hybrid library screening and in situ proximity ligation assays demonstrate that phospho-YY1^S118 directly binds zinc finger with KRAB and SCAN domains 4 (ZKSCAN4) to induce promoter activity and gene expression of human double minute 2 (HDM2), which consequently induces EC proliferation through down-regulations of p53 and p21^CIP1. Administration of apolipoprotein E-deficient (ApoE^-/-) mice with CK2-specific inhibitor tetrabromocinnamic acid or atorvastatin inhibits atherosclerosis formation through down-regulations of EC phospho-YY1^S118 and HDM2. Generation of novel transgenic mice bearing EC-specific overexpression of S118-non-phosphorylatable mutant of YY1 in ApoE^-/- mice confirms the critical role of phospho-YY1^S118 in promoting atherosclerosis through EC HDM2. Conclusions: Our findings provide new insights into the mechanisms by which disturbed flow induces endothelial phospho-YY1^S118 to promote atherosclerosis, thus indicating phospho-YY1^S118 as a potential molecular target for atherosclerosis treatment.

Innovative nanotools for vascular drug delivery: the atherosclerosis case study

Cardiovascular diseases are the leading cause of mortality in the Western world. Among them, atherosclerosis represents one of the most common diseases in the modern society due to a common sedentary lifestyle, high-fat diet, and smoking. In the near future, a new approach could potentially improve the therapy of vascular pathologies, where to date the non-specific treatments present several limitations, such as poor biodistribution, quick elimination from the body, and undesired side-effects. In this field, nanotechnology has a great potential for the therapy and diagnosis of atherosclerosis with more and more recent and innovative publications. This review is a critical analysis of the results reported in the literature regarding the different and possible new approaches for the therapy and diagnosis of atherosclerosis.

An "occlusive thrombosis-on-a-chip" microfluidic device for investigating the effect of anti-thrombotic drugs

Cardiovascular disease remains one of the world's leading causes of death. Myocardial infarction (heart attack) is triggered by occlusion of coronary arteries by platelet-rich thrombi (clots). The development of new anti-platelet drugs to prevent myocardial infarction continues to be an active area of research and is dependent on accurately modelling the process of clot formation. Occlusive thrombi can be generated in vivo in a range of species, but these models are limited by variability and lack of relevance to human disease. Although in vitro models using human blood can overcome species-specific differences and improve translatability, many models do not generate occlusive thrombi. In those models that do achieve occlusion, time to occlusion is difficult to measure in an unbiased and objective manner. In this study we developed a simple and robust approach to determine occlusion time of a novel in vitro microfluidic assay. This highlighted the potential for occlusion to occur in thrombosis microfluidic devices through off-site coagulation, obscuring the effect of anti-platelet drugs. We therefore designed a novel occlusive thrombosis-on-a-chip microfluidic device that reliably generates occlusive thrombi at arterial shear rates by quenching downstream coagulation. We further validated our device and methods by using the approved anti-platelet drug, eptifibatide, recording a significant difference in the "time to occlude" in treated devices compared to control conditions. These results demonstrate that this device can be used to monitor the effect of antithrombotic drugs on time to occlude, and, for the first time, delivers this essential data in an unbiased and objective manner.

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-A^y mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.

Severe Spontaneous Atherosclerosis in two Korat Breed Cats is Comparable to Human Atherosclerosis

Atherosclerosis is a chronic inflammatory vascular disease and the leading cause of mortality in humans worldwide. In most domestic animal species, however, primary atherosclerosis is of little clinical relevance. Cats are considered to be atheroresistant and, to our knowledge, spontaneous atherosclerosis has not been reported in cats. Here we report the clinical and histopathological findings in two related cats of the Korat breed that presented with clinical signs of heart failure. In both cases, the clinical signs appeared in adulthood, were progressive and led to death. At necropsy, severe atherosclerotic lesions were present in large and medium-sized arteries and were characterized by the formation of a fibrous cap and a lipid core, which contained a particularly large accumulation of cholesterol crystals, as indicated by the presence of many cholesterol clefts. The lesions closely resembled those of advanced human atherosclerosis. There were no underlying diseases or medical treatments that could have predisposed to the atherosclerosis in these two genetically related cats. A genetic predisposition to human-like atherosclerosis in the local Korat cat population is suspected.

Evaluation of Atherosclerotic Lesions and Risk Factors of Atherosclerosis in Raptors in Northern California

Atherosclerosis is a chronic inflammatory disease that has been reported to affect the cardiovascular system of many avian species. However, atherosclerosis in raptor species has not been fully evaluated. The aim of this study was to histologically characterize central and peripheral atherosclerotic lesions in raptors that were submitted to a pathology service in Northern California from 1986 to 2013. We also evaluated risk factors, including age, gender, origin, and avian family. Atherosclerotic lesions were categorized as minimal, mild, moderate, or severe, based on the severity of the lesions and their distribution within the arterial wall. Among the central arteries, lesions were determined to be of greater severity in the aorta than in the pulmonary artery. More than 50% of the peripheral arteries were affected, including 53.1% (17/32) myocardial, 52% (13/25) coronary, 62.9% (22/35) arteries in the kidney, 52.2% (12/23) gonadal and 51.7% (15/29) splenic arteries; however, hepatic and pulmonary arteries were uncommonly affected. Atherosclerosis was diagnosed in 17 raptor species representing 4 families: Accipitridae, Cathartidae, Falconidae, and Strigidae. The overall prevalence (95% CI) of atherosclerosis in raptors was 2.3% (36/1574; range, 1.63%-3.19%) with the Falconidae having the highest prevalence at 7.4% (9/122; range 3.64%-13.93%) and with 0% detected in the Tytonidae and Pandionidae families. A multiple logistic regression model that jointly accounted for differences in risk by family, age, and gender found that the risk in Accipitridae was significantly less than that of Falconidae, that adult raptors were at greater risk of atherosclerotic lesions than juveniles were, and that females were more frequently affected than males were.

Oxidation of Hemoglobin Drives a Proatherogenic Polarization of Macrophages in Human Atherosclerosis

Aim: The aim of our study was to explore the pathophysiologic role of oxidation of hemoglobin (Hb) to ferrylHb in human atherosclerosis. Results: We observed a severe oxidation of Hb to ferrylHb in complicated atherosclerotic lesions of carotid arteries with oxidative changes of the globin moieties, detected previously described oxidation hotspots in Hb (β1Cys93; β1Cys112; β2Cys112) and identified a novel oxidation hotspot (α1Cys104). After producing a monoclonal anti-ferrylHb antibody, ferrylHb was revealed to be localized extracellularly and also internalized by macrophages in the human hemorrhagic complicated lesions. We demonstrated that ferrylHb is taken up via phagocytosis as well as CD163 receptor-mediated endocytosis and then transported to lysosomes involving actin polymerization. Internalization of ferrylHb was accompanied by upregulation of heme oxygenase-1 and H-ferritin and accumulation of iron within lysosomes as a result of heme/iron uptake. Importantly, macrophages exposed to ferrylHb in atherosclerotic plaques exhibited a proinflammatory phenotype, as reflected by elevated levels of IL-1β and TNF-α. To find further signatures of ferrylHb in complicated lesions, we performed RNA-seq analysis on biopsies from patients who underwent endarterectomies. RNA-seq analysis demonstrated that human complicated lesions had a unique transcriptomic profile different from arteries and atheromatous plaques. Pathways affected in complicated lesions included gene changes associated with phosphoinositide 3-kinase (PI3K) signaling, lipid transport, tissue remodeling, and vascularization. Targeted analysis of gene expression associated with calcification, apoptosis, and hemolytic-specific clusters indicated an increase in the severity of complicated lesions compared with atheroma. A 39% overlap in the differential gene expression profiles of human macrophages exposed to ferrylHb and the complicated lesion profiles was uncovered. Among these 547 genes, we found inflammatory, angiogenesis, and iron metabolism gene clusters regulated in macrophages. Innovation and Conclusion: We conclude that oxidation of Hb to ferrylHb contributes to the progression of atherosclerosis via polarizing macrophages into a proatherogenic phenotype. Antioxid. Redox Signal. 35, 917-950.

Clinical Molecular Imaging for Atherosclerotic Plaque

Atherosclerosis is a well-known disease leading to cardiovascular events, including myocardial infarction and ischemic stroke. These conditions lead to a high mortality rate, which explains the interest in their prevention, early detection, and treatment. Molecular imaging is able to shed light on the basic pathophysiological processes, such as inflammation, that cause the progression and instability of plaque. The most common radiotracers used in clinical practice can detect increased energy metabolism (FDG), macrophage number (somatostatin receptor imaging), the intensity of cell proliferation in the area (labeled choline), and microcalcifications (fluoride imaging). These radiopharmaceuticals, especially FDG and labeled sodium fluoride, can predict cardiovascular events. The limitations of molecular imaging in atherosclerosis include low uptake of highly specific tracers, possible overlap with other diseases of the vessel wall, and specific features of certain tracers’ physiological distribution. A common protocol for patient preparation, data acquisition, and quantification is needed in the area of atherosclerosis imaging research.

Microsurgical Treatment Strategy of Vertebral Artery Fusiform Aneurysm-From the Standpoint of Hemodynamic Integrity and Perforator Preservation

During treatment of vertebral artery (VA) fusiform aneurysms, it is critical to preserve peripheral perforators and anterograde blood flow of the VA and to reduce hemodynamic load to the contralateral VA. Even in the era of endovascular treatment, there are still many benefits to using microsurgical treatments with appropriate clip application and preservation of the perforators around the aneurysm, in conjunction with various bypass techniques. The ideal microsurgical technique involves reconstructive clipping that obliterates the aneurysm but preserves anterograde blood flow of the VA, followed by isolation of the aneurysm and VA reconstruction. If these two methods are unavailable, proximal clipping of the aneurysm combined with flow-augmentation bypass to the distal branch can be considered as an alternative surgical management. We discuss the microsurgical treatment of unruptured VA fusiform aneurysms in our surgical cases on the basis of a review of the current literature.

Effects of sleep habits on acute myocardial infarction risk and severity of coronary artery disease in Chinese population

Background

Growing evidence indicates that poor sleep harms health. Early to bed and early to rise is considered as a healthy lifestyle in Chinese population. The current study aimed to examine the effects of sleep habits on acute myocardial infarction (AMI) risk and severity of coronary artery disease (CAD) in Chinese population from two centers.

Methods

A total of 873 patients including 314 AMI cases and 559 controls were recruited from the inpatient cardiology department of the Affiliated Jiangning Hospital and the First Affiliated Hospital of Nanjing Medical University. 559 controls included 395 CAD cases and 164 non-CAD cases. We used a 17-item sleep factors questionnaire (SFQ) to evaluate sleep habits comprehensively by face-to-face interview. The severity of CAD was assessed by Gensini score in AMI and CAD groups. The effects of sleep factors on AMI risk and Gensini score were examined by unconditional logistic regression.

Results

After mutually adjustment for other sleep factors and demographic characteristics, the timing of sleep (24:00 and after) and morning waking (after 7:00) and sleep duration (< 6 h) were associated with increased risk of AMI (OR = 4.005, P < 0.001, OR = 2.544, P = 0.011 and OR = 2.968, P < 0.001, respectively). Lower level of light exposure at night was correlated with reduced risk of AMI (OR = 0.243, P = 0.009). In subgroup analysis by age, both late sleep timing and short sleep duration were associated with increased risk of AMI regardless of age. In subjects with age ≤ 65 years, daytime napping was related to reduced risk of AMI (OR = 0.645, P = 0.046). In subjects with age > 65 years, the frequency of night-time waking (3 times) was associated with increased risk of AMI (OR = 3.467, P = 0.035). Short sleep duration was correlated with increased risk of high Gensini score (OR = 2.374, P < 0.001).

Conclusion

Sleep insufficiency is an important risk factor both for AMI risk and CAD severity. Late sleeping is also associated with increased risk of AMI. In young and middle-aged people, regular naps may have a protective effect.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02251-8.

Automatic Quantification of Atherosclerosis in Contrast-Enhanced MicroCT Scans of Mouse Aortas Ex Vivo

Objective

While microCT evaluation of atherosclerotic lesions in mice has been formally validated, existing image processing methods remain undisclosed. We aimed to develop and validate a reproducible image processing workflow based on phosphotungstic acid-enhanced microCT scans for the volumetric quantification of atherosclerotic lesions in entire mouse aortas. Approach and Results. 42 WT and 42 apolipoprotein E knockout mouse aortas were scanned. The walls, lumen, and plaque objects were segmented using dual-threshold algorithms. Aortic and plaque volumes were computed by voxel counting and lesion surface by triangulation. The results were validated against manual and histological evaluations. Knockout mice had a significant increase in plaque volume compared to wild types with a plaque to aorta volume ratio of 0.3%, 2.8%, and 9.8% at weeks 13, 18, and 26, respectively. Automatic segmentation correlated with manual (r ² ≥ 0.89; p < .001) and histological evaluations (r ² > 0.96; p < .001).

Conclusions

The semiautomatic workflow enabled rapid quantification of atherosclerotic plaques in mice with minimal manual work.

Detection of Advanced Lesions of Atherosclerosis in Carotid Arteries Using 3-Dimensional Motion-Sensitized Driven-Equilibrium Prepared Rapid Gradient Echo (3D-MERGE) Magnetic Resonance Imaging as a Screening Tool

BACKGROUND AND PURPOSE

Two-dimensional high-resolution multicontrast magnetic resonance imaging (2D-MC MRI) is currently the most reliable and reproducible noninvasive carotid vessel wall imaging technique. However, the long scan time required for 2D-MC MRI restricts its practical clinical application. Alternatively, 3-dimensional motion-sensitized driven-equilibrium prepared rapid gradient echo (3D-MERGE) vessel wall MRI can provide high isotropic resolution with extensive coverage in two minutes. In this study, we sought to prove that 3D-MERGE alone can serve as a screening tool to identify advanced carotid lesions.

METHODS

Two hundred twenty-seven subjects suspected of recent ischemic stroke or transient ischemic attack were imaged using 2D-MC MRI with an imaging time of 30 minutes, then with 3D-MERGE with an imaging time of 2 minutes, on 3T-MRI scanners. Two experienced reviewers interpreted plaque components using 2D-MC MRI as the reference standard and categorized plaques using a modified American Heart Association lesion classification for MRI. Plaques of American Heart Association type IV and above were classified as advanced. Arteries of American Heart Association types I to II and III were categorized as normal or with early lesions, respectively. One radiologist independently reviewed only 3D-MERGE and labeled the plaques as advanced if they had a wall thickness of >2 mm with high or low signal intensity compared with the adjacent sternocleidomastoid muscle. Sensitivity, specificity, and accuracy for 3D-MERGE were calculated.

RESULTS

Four hundred forty-nine arteries from 227 participants (mean age 61.2 years old, 64% male) were included in the analysis. Sensitivity, specificity, and accuracy for identification of advanced lesions on 3D-MERGE were 95.0% (95% CI, 91.8-97.2), 86.9% (95% CI, 81.4-92.0), 93.8% (95% CI, 91.1-95.8), respectively.

CONCLUSIONS

3D-MERGE can accurately identify advanced carotid atherosclerotic plaques in patients suspected of stroke or transient ischemic attack. It has a more extensive coverage and higher sensitivity and specificity for advanced plaque detection with a much shorter acquisition time than 2D-MC MRI.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02017756.

Recent Trends in Artificial Intelligence-Assisted Coronary Atherosclerotic Plaque Characterization

Coronary artery disease is a major cause of morbidity and mortality worldwide. Its underlying histopathology is the atherosclerotic plaque, which comprises lipid, fibrous and—when chronic—calcium components. Intravascular ultrasound (IVUS) and intravascular optical coherence tomography (IVOCT) performed during invasive coronary angiography are reference standards for characterizing the atherosclerotic plaque. Fine image spatial resolution attainable with contemporary coronary computed tomographic angiography (CCTA) has enabled noninvasive plaque assessment, including identifying features associated with vulnerable plaques known to presage acute coronary events. Manual interpretation of IVUS, IVOCT and CCTA images demands scarce physician expertise and high time cost. This has motivated recent research into and development of artificial intelligence (AI)-assisted methods for image processing, feature extraction, plaque identification and characterization. We performed parallel searches of the medical and technical literature from 1995 to 2021 focusing respectively on human plaque characterization using various imaging modalities and the use of AI-assisted computer aided diagnosis (CAD) to detect and classify atherosclerotic plaques, including their composition and the presence of high-risk features denoting vulnerable plaques. A total of 122 publications were selected for evaluation and the analysis was summarized in terms of data sources, methods—machine versus deep learning—and performance metrics. Trends in AI-assisted plaque characterization are detailed and prospective research challenges discussed. Future directions for the development of accurate and efficient CAD systems to characterize plaque noninvasively using CCTA are proposed.

Optical Coherence Tomography of Coronary Plaque Progression and Destabilization: JACC Focus Seminar Part 3/3

The development of optical coherence tomography (OCT) has revolutionized our understanding of coronary artery disease. In vivo OCT research has paralleled with advances in computational fluid dynamics, providing additional insights in the various hemodynamic factors influencing plaque growth and stability. Recent OCT studies introduced a new concept of plaque healing in relation to clinical presentation. In addition to known mechanisms of acute coronary syndromes such as plaque rupture and plaque erosion, a new classification of calcified plaque was recently reported. This review will focus on important new insights that OCT has provided in recent years into coronary plaque development, progression, and destabilization, with a focus on the role of local hemodynamics and endothelial shear stress, the layered plaque (signature of previous subclinical plaque destabilization and healing), and the calcified culprit plaque.

Medial Arterial Calcification: JACC State-of-the-Art Review

Medial arterial calcification (MAC) is a chronic systemic vascular disorder distinct from atherosclerosis that is frequently but not always associated with diabetes mellitus, chronic kidney disease, and aging. MAC is also a part of more complex phenotypes in numerous less common diseases. The hallmarks of MAC include disseminated and progressive precipitation of calcium phosphate within the medial layer, a prolonged and clinically silent course, and compromise of hemodynamics associated with chronic limb-threatening ischemia. MAC increases the risk of complications during vascular interventions and mitigates their outcomes. With the exception of rare monogenetic defects affecting adenosine triphosphate metabolism, MAC pathogenesis remains unknown, and causal therapy is not available. Implementation of genetics and omics-based approaches in research recognizing the critical importance of calcium phosphate thermodynamics holds promise to unravel MAC molecular pathogenesis and to provide guidance for therapy. The current state of knowledge concerning MAC is reviewed, and future perspectives are outlined.

Computed tomography of coronary artery atherosclerosis: A review

Coronary artery atherosclerosis resulting in ischemic cardiac disease is the leading cause of mortality in the United States. In symptomatic patients, invasive diagnostic methods like catheter angiography, intravascular ultrasound, or vascular endoscopy may be used. However, for primary prevention of atherosclerotic coronary artery disease in asymptomatic patients, non-invasive methods are more commonly utilized like stress imaging, single-photon emission computed tomography (SPECT) and coronary artery calcification scoring. Coronary computed tomographic angiography (CCTA) is an excellent diagnostic tool for detection of coronary artery plaque and ability to identify resultant stenoses with an excellent negative predictive value which can potentially result in optimal exclusion of the presence of coronary artery disease. Long term follow up after a negative CCTA has repeatedly demonstrated very low incidence of future adverse coronary events, attesting its predictive value. CCTA based management is associated with improved CAD outcome in stable angina. Coronary CTA is valuable in acute chest pain evaluation in the emergency department helping in better triage. CT perfusion and CT-FFR are both very promising tools for assessment of hemodynamic significance of coronary artery stenosis.

Bioinformatics analysis reveals the landscape of immune cell infiltration and immune-related pathways participating in the progression of carotid atherosclerotic plaques

Atherosclerosis is a systemic disease associated with inflammatory cell infiltration and activation of immune-related pathways. In our study, we aimed to uncover immune-related changes and explore novel immunological features in the development of carotid atherosclerotic plaques. First, we applied integrated bioinformatics methods, including CIBERSORT and gene set enrichment analysis (GSEA). The gene expression matrices GSE28829, GSE41571, and GSE43292 were obtained from the Gene Expression Omnibus (GEO) dataset. After a series of data pre-processing steps, the resulting combined expression matrices were analysed using the CIBERSORT, GSEA, and Cluster Profiler packages. After the comparison and analysis between the carotid atherosclerotic plaques in the early and advanced stages, we discovered that there is a higher percentage of activated memory CD4 T cells and a lower percentage of resting memory CD4 cells in advanced-stage plaques. Moreover, activation of memory CD4 T cells can promote the development of carotid atherosclerotic plaques. Additionally, FOXP3⁺ Treg cell maturation can also participate in the progression of carotid plaques.

Multispectral optoacoustic tomography of lipid and hemoglobin contrast in human carotid atherosclerosis

Several imaging techniques aim at identifying features of carotid plaque instability but come with limitations, such as the use of contrast agents, long examination times and poor portability. Multispectral optoacoustic tomography (MSOT) employs light and sound to resolve lipid and hemoglobin content, both features associated with plaque instability, in a label-free, fast and highly portable way. Herein, 5 patients with carotid atherosclerosis, 5 healthy volunteers and 2 excised plaques, were scanned with handheld MSOT. Spectral unmixing allowed visualization of lipid and hemoglobin content within three ROIs: whole arterial cross-section, plaque and arterial lumen. Calculation of the fat-blood-ratio (FBR) value within the ROIs enabled the differentiation between patients and healthy volunteers (P = 0.001) and between plaque and lumen in patients (P = 0.04). Our results introduce MSOT as a tool for molecular imaging of human carotid atherosclerosis and open new possibilities for research and clinical assessment of carotid plaques.

A narrative review of the pathophysiology of ischemic stroke in carotid plaques: a distinction versus a compromise between hemodynamic and embolic mechanism

Atherosclerotic carotid artery stenosis causes about 10–20% of all ischemic strokes through two main mechanisms: hemodynamic impairment in case of significant stenosis and thromboembolism from an atherosclerotic plaque regardless of the degree of stenosis. The latter is the most frequent mechanism and appear to result from embolization from a vulnerable atherosclerotic plaque or acute occlusion of the carotid artery and propagation of thrombus distally. Downstream infarcts may occur in a territory of major cerebral artery or at the most distal areas between two territories of major cerebral arteries, the so-called watershed (WS), or border zone area. Although WS infarcts, especially deep WS infarct, were historically thought to be due to hemodynamic compromise, the role of microembolism has also been documented, both mechanisms may act synergistically to promote WS infarcts. Routine and more advanced imaging techniques may provide information on the underlying mechanism involved in ipsilateral ischemic stroke. A better understanding of ischemic stroke pathogenesis in carotid stenosis may limit the use of routine non-selective shunt, whose benefit-risk balance is debated, to patients with hemodynamic impairment.

After reviewing existing evidence underpinning the contribution of the two mechanisms in downstream ischemic stroke and the various imaging techniques available to investigate them, we will focus on the pathogenesis of WS infarcts that remains debated.

Silencing Myeloid Netrin-1 Induces Inflammation Resolution and Plaque Regression

Rationale: Therapeutic efforts to decrease atherosclerotic cardiovascular disease risk have focused largely on reducing atherogenic lipoproteins, yet lipid-lowering therapies alone are insufficient to fully regress plaque burden. We postulate that arterial repair requires resolution of a maladaptive immune response and that targeting factors that hinder inflammation resolution will facilitate plaque regression. Objective: The guidance molecule Ntn1 (netrin-1) is secreted by macrophages in atherosclerotic plaques, where it sustains inflammation by enhancing macrophage survival and blocking macrophage emigration. We tested whether silencing Ntn1 in advanced atherosclerosis could resolve arterial inflammation and regress plaques. Methods and Results: To temporally silence Ntn1 in myeloid cells, we generated genetically modified mice in which Ntn1 could be selectively deleted in monocytes and macrophages using a tamoxifen-induced CX3CR1-driven cre recombinase (Ntn1fl/flCx3cr1creERT2+) and littermate control mice (Ntn1fl/flCx3cr1WT). Mice were fed Western diet in the setting of hepatic PCSK9 (proprotein convertase subtilisin/kexin type 9) overexpression to render them atherosclerotic and then treated with tamoxifen to initiate deletion of myeloid Ntn1 (MøΔNtn1) or not in controls (MøWT). Morphometric analyses performed 4 weeks later showed that myeloid Ntn1 silencing reduced plaque burden in the aorta (−50%) and plaque complexity in the aortic root. Monocyte-macrophage tracing experiments revealed lower monocyte recruitment, macrophage retention, and proliferation in MøΔNtn1 compared with MøWT plaques, indicating a restructuring of monocyte-macrophage dynamics in the artery wall upon Ntn1 silencing. Single-cell RNA sequencing of aortic immune cells before and after Ntn1 silencing revealed upregulation of gene pathways involved in macrophage phagocytosis and migration, including the Ccr7 chemokine receptor signaling pathway required for macrophage emigration from plaques and atherosclerosis regression. Additionally, plaques from MøΔNtn1 mice showed hallmarks of inflammation resolution, including higher levels of proresolving macrophages, IL (interleukin)-10, and efferocytosis, as compared to plaques from MøWT mice. Conclusion: Our data show that targeting Ntn1 in advanced atherosclerosis ameliorates atherosclerotic inflammation and promotes plaque regression.