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Coronary computed tomography angiography (CTA) allows for the assessment of atherosclerotic plaque burden across the entire coronary vasculature. No studies have examined the relationship between the underlying pathology of the culprit lesion and total plaque burden in patients with acute coronary syndromes. The aim of this study was to compare the total plaque burden between patients with plaque rupture versus plaque erosion. A total of 232 patients who presented with their first non-ST-segment elevation acute coronary syndrome and underwent both CTA and optical coherence tomography imaging before intervention were selected. Quantitative analysis was performed using semi-automated software (Autoplaque version 3.0, Cedars-Sinai Medical Center). An attenuation of <30 Hounsfield units defined low-density non-calcified plaque (LDNCP). All 3 vessels were assessed using the modified 17-segment American Heart Association model for coronary segment classification. Among 232 patients, 125 (53.9%) had plaque rupture and 107 (46.1%) had plaque erosion. Total plaque burden (48.2 [39.8–54.9] % vs. 44.1 [38.6–50.0] %, P ​= ​0.006), total non-calcified plaque (NCP) burden (46.6 [39.1–53.3] % vs. 43.0 [37.6–49.2] %, P ​= ​0.013), total LDNCP burden (2.3 [1.4–3.0] % vs. 1.7 [1.2–2.6] %, P ​= ​0.016), and total calcified plaque (CP) burden (0.8 [0.1–1.6] % vs. 0.4 [0.0–1.4] %, P ​= ​0.047) were significantly greater in patients with culprit plaque rupture than in those with culprit plaque erosion. Patients with plaque rupture, compared with those with plaque erosion, had a greater total plaque burden, NCP burden, LDNCP burden, and CP burden. URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04523194. Patients with plaque rupture had a greater total plaque burden than those with plaque erosion. LAD ​= ​left anterior descending artery; LCX ​= ​left circumflex artery; RCA ​= ​right coronary artery. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Background Metabolism is increasingly recognized as a key regulator of the function and phenotype of the primary cellular constituents of the atherosclerotic vascular wall, including endothelial cells, smooth muscle cells, and inflammatory cells. However, a comprehensive analysis of metabolic changes associated with the transition of plaque from a stable to a hemorrhaged phenotype is lacking. Methods In this study, we integrated two large mRNA expression and protein abundance datasets (BIKE, n = 126; MaasHPS, n = 43) from human atherosclerotic carotid artery plaque to reconstruct a genome-scale metabolic network (GEM). Next, the GEM findings were linked to metabolomics data from MaasHPS, providing a comprehensive overview of metabolic changes in human plaque. Results Our study identified significant changes in lipid, cholesterol, and inositol metabolism, along with altered lysosomal lytic activity and increased inflammatory activity, in unstable plaques with intraplaque hemorrhage (IPH+) compared to non-hemorrhaged (IPH−) plaques. Moreover, topological analysis of this network model revealed that the conversion of glutamine to glutamate and their flux between the cytoplasm and mitochondria were notably compromised in hemorrhaged plaques, with a significant reduction in overall glutamate levels in IPH+ plaques. Additionally, reduced glutamate availability was associated with an increased presence of macrophages and a pro-inflammatory phenotype in IPH+ plaques, suggesting an inflammation-prone microenvironment. Conclusions This study is the first to establish a robust and comprehensive GEM for atherosclerotic plaque, providing a valuable resource for understanding plaque metabolism. The utility of this GEM was illustrated by its ability to reliably predict dysregulation in the cholesterol hydroxylation, inositol metabolism, and the glutamine/glutamate pathway in rupture-prone hemorrhaged plaques, a finding that may pave the way to new diagnostic or therapeutic measures.

This article discusses a new mouse model that closely mimics the development of myocardial infarction, stroke, and plaque rupture, which are leading causes of death worldwide. The model allows for the study of smooth muscle cell transition in advanced lesions and has been shown to be useful in testing the effects of therapeutics. Treatment with an extracellular myeloperoxidase inhibitor improved survival and reduced major adverse cardiovascular events in the model. This mouse model has the potential to enhance the development of drugs targeting plaque instability and improve success rates in clinical development. [Extracted from the article]

Background: Acute myocardial infarction (AMI) can occur in patients with atherosclerotic disease, with or without plaque rupture. Previous studies have indicated a set of immune responses to plaque rupture. However, the specific circulating immune cell subsets that mediate inflammatory plaque rupture remain elusive. Methods: Ten AMI patients were enrolled in our study (five with and five without plaque rupture; plaque characteristics were identified by optical coherence tomography). By single-cell RNA sequencing, we analyzed the transcriptomic profile of peripheral blood mononuclear cells. Results: We identified 27 cell clusters among 82,550 cells, including monocytes, T cells, NK cells, B cells, megakaryocytes, and CD34+ cells. Classical and non-classical monocytes constitute the major inflammatory cell types, and pro-inflammatory genes such as CCL5, TLR7, and CX3CR1 were significantly upregulated in patients with plaque rupture, while the neutrophil activation and degranulation genes FPR2, MMP9, and CLEC4D were significantly expressed in the intermediate monocytes derived from patients without plaque rupture. We also found that CD4+ effector T cells may contribute to plaque rupture by producing a range of cytokines and inflammatory-related chemokines, while CD8+ effector T cells express more effector molecules in patients without plaque rupture, such as GZMB, GNLY, and PRF1, which may contribute to the progress of plaque erosion. Additionally, NK and B cells played a significant role in activating inflammatory cells and promoting chemokine production in the plaque rupture. Cell--cell communication elaborated characteristics in signaling pathways dominated by inflammatory activation of classical monocytes in patients with plaque rupture. Conclusions: Our studies demonstrate that the circulating immune cells of patients with plaque rupture exhibit highly pro-inflammatory characteristics, while plaque erosion is mainly associated with intermediate monocyte amplification, neutrophil activation, and degranulation. These findings may provide novel targets for the precise treatment of patients with AMI. [ABSTRACT FROM AUTHOR]

Background: Metabolism is increasingly recognized as a key regulator of the function and phenotype of the primary cellular constituents of the atherosclerotic vascular wall, including endothelial cells, smooth muscle cells, and inflammatory cells. However, a comprehensive analysis of metabolic changes associated with the transition of plaque from a stable to a hemorrhaged phenotype is lacking. Methods: In this study, we integrated two large mRNA expression and protein abundance datasets (BIKE, n = 126; MaasHPS, n = 43) from human atherosclerotic carotid artery plaque to reconstruct a genome-scale metabolic network (GEM). Next, the GEM findings were linked to metabolomics data from MaasHPS, providing a comprehensive overview of metabolic changes in human plaque. Results: Our study identified significant changes in lipid, cholesterol, and inositol metabolism, along with altered lysosomal lytic activity and increased inflammatory activity, in unstable plaques with intraplaque hemorrhage (IPH+) compared to non-hemorrhaged (IPH−) plaques. Moreover, topological analysis of this network model revealed that the conversion of glutamine to glutamate and their flux between the cytoplasm and mitochondria were notably compromised in hemorrhaged plaques, with a significant reduction in overall glutamate levels in IPH+ plaques. Additionally, reduced glutamate availability was associated with an increased presence of macrophages and a pro-inflammatory phenotype in IPH+ plaques, suggesting an inflammation-prone microenvironment. Conclusions: This study is the first to establish a robust and comprehensive GEM for atherosclerotic plaque, providing a valuable resource for understanding plaque metabolism. The utility of this GEM was illustrated by its ability to reliably predict dysregulation in the cholesterol hydroxylation, inositol metabolism, and the glutamine/glutamate pathway in rupture-prone hemorrhaged plaques, a finding that may pave the way to new diagnostic or therapeutic measures. [ABSTRACT FROM AUTHOR]

Background Bioresorbable scaffolds (BRS) have been proposed as an alternative to drug-eluting stents (DES), offering radial support during the early phases of healing, while potentially reducing the risk of long-term complications. A magnesium-based BRS (MgBRS) has shown promising results after implantation. However, there is a lack of knowledge regarding the long-term outcomes. Case summary A 62-year-old man with hypertension, dyslipidaemia, family history of ischaemic heart disease, and previous myocardial infarction, presented with non-ST-elevation myocardial infarction (NSTEMI). Six years prior, he also had a NSTEMI and a mid-left anterior descending artery (LAD) lesion was treated with a 3.0/25 mm MgBRS. Post-implantation optical coherence tomography (OCT) revealed proximal edge dissection, and a second MgBRS 3.0/15 mm was implanted. Optical coherence tomography of the scaffold-treated segment was performed after 6 and 12 months with no sign of restenosis. The current angiogram showed a restenosis in the previously MgBRS-treated segment in LAD. Optical coherence tomography showed a plaque rupture in a thin cap fibro-atheroma and scaffold remnants. The lesion was pre-dilated and stented with a 3.0/20 mm DES and post-dilated with a 3.5 mm non-compliant balloon. Discussion Most cases of late scaffold failure showed acquired mal-apposition, which also can be related to the degrading process, or uncovered struts, none of which were seen in our case at 6 or 12 months. This case represents an insight into the vascular healing and potential mechanisms for failure of the MgBRS, with serial OCT recording at implantation, and after 6 months, 12 months, and 6 years. [ABSTRACT FROM AUTHOR]

In this study, the growth and rupture of plaque were investigated to predict the development of carotid atherosclerosis and plaque. Realistic 3D models of multi-component plaque and carotid artery were established in healthy, mild, moderate, and severe stenosis. Fluid–structure interaction (FSI) simulations were performed on these models, and the wall shear stress (WSS), time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and wall tensile stress (WTS) in a natural cardiac cycle were analyzed to assess the epidermal rupture, growth tendency, and internal rupture of plaques in a natural state. Results show that in severe stenosis, the WSS at the stenosis sites exceeds the threshold of rupture during almost the entire cardiac cycle, thus causing an epidermal injury, bringing about plaque detachment and thrombosis. TAWSS decreased and OSI and RRT increased in the bifurcation region and the downstream region of the plaque. The deposition is more likely to occur in these regions. A higher degree of stenosis will increase the OSI and RRT in the downstream region of the plaque, leading to continuous deterioration of the plaque, while the degree of stenosis has little effect on the upstream region of the plaque. The fibrous cap is the starting point for rupture within the plaque, and calcification increases the stress on the fibrous cap, thereby increasing the risk of rupture. [ABSTRACT FROM AUTHOR]

Catheter reaction forces during transcatheter valve replacement (TAVR) may result in injury to the vessel or plaque rupture, triggering distal embolization or thrombosis. In vitro test methods represent the arterial wall using synthetic proxies to determine catheter reaction forces during tracking, but whether they can account for reaction forces within the compliant aortic wall tissue in vivo is unknown. Moreover, the role of plaque inclusions is not well understood. Computational approaches have predicted the impact of TAVR positioning, migration, and leaflet distortion, but have not yet been applied to investigate aortic wall reaction forces and stresses during catheter tracking. In this study, we investigate the role that catheter design and aorta and plaque mechanical properties have on the risk of plaque rupture during TAVR catheter delivery. We report that, for trackability testing, a rigid test model provides a reasonable estimation of the peak reaction forces experienced during catheter tracking within compliant vessels. We investigated the risk of rupture of both the aortic tissue and calcified plaques. We report that there was no risk of diseased aortic tissue rupture based on an accepted aortic tissue stress threshold (4.2 MPa). However, we report that both the aortic and plaque tissue exceed a rupture stress threshold (300 kPa) with and without the presence of stiff and soft plaque inclusions. We also highlight the potential risks associated with shorter catheter tips during catheter tracking and demonstrate that increasing the contact surface will reduce peak contact pressures experienced in the tissue. [ABSTRACT FROM AUTHOR]

Patients with acute coronary syndrome (ACS), frequently caused by plaque rupture (PR), often have vulnerable plaques in residual lesions as well as in culprit lesions. However, whether this occurs in patients with plaque erosion (PE) as well is unknown. We retrospectively analyzed the data of 88 patients with ACS who underwent both optimal coherence tomography (OCT) and intravascular ultrasound (IVUS). Based on plaque morphology of the culprit lesions identified using OCT, patients were classified into PE (n=23) and PR (n=35) groups. The tissue characteristics of residual lesions evaluated using integrated backscatter IVUS were compared between both groups after percutaneous coronary intervention. The PE group had a significantly lower percent lipid volume and a higher percent fibrous volume than the PR group (35.0±17.8% vs 49.2±13.4%, p<0.001; 63.2±17.1% vs 50.3±13.1%, p=0.002, respectively). Receiver operating characteristic curve analysis revealed that percent lipid volume in the residual lesions was a significant discriminant factor in estimating the plaque morphology of the culprit lesion (optimal cut-off value, <43.5%; sensitivity and specificity values were 73.9% and 68.6%, respectively). In conclusion, patients with PE had a significantly lower percent lipid volume and a significantly higher percent fibrous volume in the residual lesions than those with PR, suggesting that the nature of coronary plaques in patients with PE is different from that of those with PR. [ABSTRACT FROM AUTHOR]

Background: Endothelial dysfunction, characterized by impaired flow-mediated vasodilation (FMD), is associated with atherosclerosis. However, the relationship between FMD, plaque morphology, and clinical outcomes in patients with acute coronary syndrome (ACS) remains underexplored. This study aims to investigate the influence of FMD on the morphology of culprit plaques and subsequent clinical outcomes in patients with ACS. Methods: This study enrolled 426 of 2482 patients who presented with ACS and subsequently underwent both preintervention FMD and optical coherence tomography (OCT) between May 2020 and July 2022. Impaired FMD was defined as an FMD% less than 7.0%. Major adverse cardiac events (MACEs) included cardiac death, nonfatal myocardial infarction, revascularization, or rehospitalization for angina. Results: Within a one-year follow-up, 34 (8.0%) patients experienced MACEs. The median FMD% was 4.0 (interquartile range 2.6-7.0). Among the patients, 225 (52.8%) were diagnosed with plaque rupture (PR), 161 (37.8%) with plaque erosion (PE), and 25 (5.9%) with calcified nodules (CN). Impaired FMD was found to be associated with plaque rupture (odds ratio [OR] = 4.22, 95% confidence interval [CI]: 2.07-6.72, p = 0.012) after adjusting for potential confounding factors. Furthermore, impaired FMD was linked to an increased incidence of MACEs (hazard ratio [HR] = 3.12, 95% CI: 1.27-6.58, p = 0.039). Conclusions: Impaired FMD was observed in three quarters of ACS patients and can serve as a noninvasive predictor of plaque rupture and risk for future adverse cardiac outcomes. [ABSTRACT FROM AUTHOR]

Mast cells (MCs) are commonly recognized for their crucial involvement in the pathogenesis of allergic diseases, but over time, it has come to light that they also play a role in the pathophysiology of non-allergic disorders including atherosclerosis. The involvement of MCs in the pathology of atherosclerosis is supported by their accumulation in atherosclerotic plaques upon their progression and the association of intraplaque MC numbers with acute cardiovascular events. MCs that accumulate within the atherosclerotic plaque release a cocktail of mediators through which they contribute to neovascularization, plaque progression, instability, erosion, rupture, and thrombosis. At a molecular level, MC-released proteases, especially cathepsin G, degrade low-density lipoproteins (LDL) and mediate LDL fusion and binding of LDL to proteoglycans (PGs). Through a complicated network of chemokines including CXCL1, MCs promote the recruitment of among others CXCR2+ neutrophils, therefore, aggravating the inflammation of the plaque environment. Additionally, MCs produce extracellular traps which worsen inflammation and contribute to atherothrombosis. Altogether, evidence suggests that MCs actively, via several underlying mechanisms, contribute to atherosclerotic plaque destabilization and acute cardiovascular syndromes, thus, making the study of interventions to modulate MC activation an interesting target for cardiovascular medicine. [ABSTRACT FROM AUTHOR]

The concept that the culprit lesion in non-ST segment elevation myocardial infarction (NSTEMI) is caused by sudden plaque rupture with acute thrombus formation has recently been challenged. While angiography is an old gold-standard for culprit identification it merely visualizes the lumen contour. Optical coherence tomography (OCT) provides a detailed view of culprit features. Combined with myocardial edema on cardiac magnetic resonance (CMR), indicating acute ischemia and thus culprit location, we aimed to characterize culprit lesions using OCT. Patients with NSTEMI referred for angiography were prospectively enrolled. OCT was performed on angiographic stenoses ≥50% and on operator-suspected culprit lesions. Hierarchical OCT-culprit identifiers were defined in case of multiple unstable lesions, including OCT-defined thrombus age. An OCT-based definition of an organizing thrombus as corresponding to histological early healing stage was introduced. Lesions were classified as OCT-culprit or non-culprit, and characteristics compared. CMR was performed in a subset of patients. We included 65 patients with 97 lesions, of which 49 patients (75%) had 53 (54%) OCT-culprit lesions. The most common OCT-culprit identifiers were the presence of acute (66%) and organizing thrombus (19%). Plaque rupture was visible in 45% of OCT-culprit lesions. CMR performed in 38 patients revealed myocardial oedema in the corresponding territories of 67% of acute thrombi and 50% of organizing thrombi. A culprit lesion was identified by OCT in 75% patients with NSTEMI. Acute thrombus was the most frequent feature followed by organizing thrombus. Applying specific OCT-criteria to identify the culprit could prove valuable in ambiguous cases. [ABSTRACT FROM AUTHOR]

Proteoglycans are differentially expressed in different atherosclerotic plaque phenotypes, with biglycan and decorin characteristic of ruptured plaques and versican and hyaluronan more prominent in eroded plaques. Following plaque disruption, the exposure of extracellular matrix (ECM) proteins triggers platelet adhesion and thrombus formation. In this study, the impact of differential plaque composition on platelet function and thrombus formation was investigated. Platelet adhesion, activation and thrombus formation under different shear stress conditions were assessed in response to individual proteoglycans and composites representing different plaque phenotypes. The results demonstrated that all the proteoglycans tested mediated platelet adhesion but not platelet activation, and the extent of adhesion observed was significantly lower than that observed with type I and type III collagens. Thrombus formation upon the rupture and erosion ECM composites was significantly reduced (p < 0.05) compared to relevant collagen alone, indicating that proteoglycans negatively regulate platelet collagen responses. This was supported by results demonstrating that the addition of soluble biglycan or decorin to whole blood markedly reduced thrombus formation on type I collagen (p < 0.05). Interestingly, thrombus formation upon the erosion composite displayed aspirin sensitivity, whereas the rupture composite was intensive to aspirin, having implications for current antiplatelet therapy regimes. In conclusion, differential platelet responses and antiplatelet efficacy are observed on ECM composites phenotypic of plaque rupture and erosion. Proteoglycans inhibit thrombus formation and may offer a novel plaque-specific approach to limit arterial thrombosis. [ABSTRACT FROM AUTHOR]

Immune-mediated acute coronary syndrome, also known as Kounis syndrome (KS), is an underrecognized and challenging diagnosis. In this case report, we present a case of cardiac arrest secondary to iodinated contrast allergy requiring emergent cardiac catheterization and hemodynamic support secondary to type 2 KS. KS necessitates a high index of clinical suspicion by the treating physician in order to address both the hypersensitivity reaction and its cardiac implications. Kounis syndrome (KS) is a clinically distinct entity from anaphylaxis; managing KS in the same way as anaphylaxis can worsen cardiac demand and ischemia. In addition, KS may present as coronary vasospasm or plaque rupture; regardless, percutaneous coronary intervention (PCI) should be performed as worse outcomes have been described in cases where PCI is not performed or delayed. [ABSTRACT FROM AUTHOR]

The leading cause of heart disease in developed countries is coronary atherosclerosis, which is not simply a result of ageing but a chronic inflammatory process that can lead to acute clinical events upon atherosclerotic plaque rupture or erosion and arterial thrombus formation. The composition and location of atherosclerotic plaques determine the phenotype of the lesion and whether it is more likely to rupture or to erode. Although plaque rupture and erosion both initiate platelet activation on the exposed vascular surface, the contribution of platelets to thrombus formation differs between the two phenotypes. In this review, plaque phenotype is discussed in relation to thrombus composition, and an overview of important mediators (haemodynamics, matrix components, and soluble factors) in plaque-induced platelet activation is given. As thrombus formation on disrupted plaques does not necessarily result in complete vessel occlusion, plaque healing can occur. Therefore, the latest findings on plaque healing and the potential role of platelets in this process are summarized. Finally, the clinical need for more effective antithrombotic agents is highlighted. [ABSTRACT FROM AUTHOR]

Background Neoatherosclerosis, a prominent contributor to in-stent restenosis (ISR), persists as a formidable challenge during percutaneous coronary intervention. Excimer laser coronary atherectomy (ELCA) and embolic protection devices may help reduce coronary flow disturbance from procedure-related distal embolization. Case summary A 71-year-old man experienced in-stent neoatherosclerosis rupture–related non-ST segment elevation myocardial infarction. Multidisciplinary intracoronary imaging, including intravascular ultrasound and optical coherence tomography (OCT), suggested that the ISR was caused by a neoatherosclerosis rupture that can potentially lead to distal embolization. Excimer laser coronary atherectomy (fluence, 45 mJ/mm2 and frequency, 25 pulse/s) using a 1.7 mm concentric catheter was performed with distal protection using Filtrap (Nipro Corporation, Tokyo, Japan), which significantly reduced the volume of the neoatherosclerosis. However, subsequent ELCA on the highest setting (fluence, 60 mJ/mm2 and frequency, 40 pulse/s) led to a filter no-reflow phenomenon, although OCT revealed a further effective vaporization of the neoatherosclerosis and an apparent reduction of soft tissue compatible with the thrombus. After removing the embolic protection device, drug-coated balloon angioplasty provided optimal results without coronary flow disturbance. Discussion Excimer laser coronary atherectomy reduces soft plaque and thrombus burden, which can reduce the occurrence of distal embolization in select cases. In the case of this patient, procedure-related distal embolization may have been induced by the heightened photomechanical effects resulting from the use of the highest setting in ELCA under increased intracoronary arterial pressure caused by continuous saline injection during ELCA. Concomitant distal protection during ELCA may be more feasible for preventing coronary flow disturbance in patients with a large amount of neoatherosclerosis. [ABSTRACT FROM AUTHOR]

A warning sign for impending cardiovascular events is not fully established. In the process of plaque rupture, the formation of vulnerable plaque is important, and oxidized cholesterols play an important role in its progression. Furthermore, the significance of vasa vasorum penetrating the medial smooth muscle layer and being rich in atheromatous lesions should be noted. The cardio-ankle vascular index (CAVI) is a new arterial stiffness index of the arterial tree from the origin of the aorta to the ankle. The CAVI reflects functional stiffness, in addition to structural stiffness. The rapid rise in the CAVI means medial smooth muscle cell contraction and strangling vasa vasorum. A rapid rise in the CAVI in people after a big earthquake, following a high frequency of cardiovascular events has been reported. There are several cases that showed a rapid rise in the CAVI a few weeks or months before suffering cardiovascular events. To explain these sequences of events, we proposed a hypothesis: a rapid rise in the CAVI means medial smooth muscle contraction, strangling vasa vasorum, leading to ischemia and the necrosis of vulnerable plaque, and then the plaque ruptures. In individuals having a high CAVI, further rapid rise in the CAVI might be a warning sign for impending cardiovascular events. In such cases, treatments to decrease the CAVI better be taken soon. [ABSTRACT FROM AUTHOR]

BackgroundInflammation is pivotal to the progression of atherosclerosis. Cholesterol crystals (CCs) that grow and enlarge within the plaque core can cause plaque rupture and trigger inflammation as they deposit into the atherosclerotic bed. Thus, agents that affect CC formation, expansion, and morphology may reduce cardiovascular (CV) risk independent of lipid-lowering and anti-inflammatory therapy.ObjectiveBecause colchicine is highly concentrated in leukocytes that can enter the atherosclerotic plaque core, we tested its effect on the formation and growth of CCs in bench experiments to determine whether it may have direct effects on CCs, independent of its known anti-inflammatory actions.MethodDifferent dosages of colchicine mixed with cholesterol (0.05–5 mg/ml/g of cholesterol) were used to influence the formation CCs and volume expansion in vitro. These were compared to control samples with cholesterol in ddH2O without colchicine. In an ex vivo study, fresh atherosclerotic human plaques were incubated with and without colchicine in a water bath at 37°C for 48 h to assess the impact of colchicine on CC morphology. Scanning electron microscopy (SEM) was utilized to analyze CC morphology in samples from the various treatment groups.ResultsThe addition of colchicine to cholesterol caused a substantial dose-dependent reduction in volume (p

The vascular extracellular matrix (ECM) produced by endothelial and smooth muscle cells is composed of collagens and glycoproteins and plays an integral role in regulating the structure and function of the vascular wall. Alteration in the expression of these proteins is associated with endothelial dysfunction and has been implicated in the development and progression of atherosclerosis. The ECM composition of atherosclerotic plaques varies depending on plaque phenotype and vulnerability, with distinct differences observed between ruptured and erodes plaques. Moreover, the thrombi on the exposed ECM are diverse in structure and composition, suggesting that the best antithrombotic approach may differ depending on plaque phenotype. This review provides a comprehensive overview of the role of proteoglycans in atherogenesis and thrombosis. It discusses the differential expression of the proteoglycans in different plaque phenotypes and the potential impact on platelet function and thrombosis. Finally, the review highlights the importance of this concept in developing a targeted approach to antithrombotic treatments to improve clinical outcomes in cardiovascular disease. [ABSTRACT FROM AUTHOR]

Coronary artery disease and acute coronary syndromes are accountable for significant morbidity and mortality, despite the preventive measures and technological advancements in their management. Thus, it is mandatory to further explore the pathophysiology in order to provide tailored and more effective therapies, since acute coronary syndrome pathogenesis is more varied than previously assumed. It consists of plaque rupture, plaque erosion, and calcified nodules. The advancement of vascular imaging tools has been critical in this regard, redefining the epidemiology of each mechanism. When it comes to acute coronary syndrome management, the presence of ruptured plaques almost always necessitates emergent reperfusion, whereas the presence of plaque erosions may indicate the possibility of conservative management with potent antiplatelet and anti-atherosclerotic medications. Calcified nodules, on the other hand, are an uncommon phenomenon that has largely gone unexplored in terms of the best management plan. Future studies should further establish the importance of detecting the underlying mechanism and the role of various treatment plans in each of these distinct entities. [ABSTRACT FROM AUTHOR]

Atherosclerotic plaque rupture in carotid arteries is a major cause of cerebrovascular events. Plaque rupture is the mechanical failure of the heterogeneous fibrous plaque tissue. Local characterization of the tissue's failure properties and the collagen architecture are of great importance to have insights in plaque rupture for clinical event prevention. Previous studies were limited to average rupture properties and global structural characterization, and did not provide the necessary local information. In this study, we assessed the local collagen architecture and failure properties of fibrous plaque tissue, by analyzing 30 tissue strips from 18 carotid plaques. Our study framework entailed second harmonic generation imaging for local collagen orientation and dispersion, and uniaxial tensile testing and digital image correlation for local tissue mechanics. The results showed that 87% of the imaged locations had collagen orientation close to the circumferential direction (0°) of the artery, and substantial dispersion locally. All regions combined, median [Q1:Q3] of the predominant angle measurements was -2° [-16°:16°]. The stretch ratio measurements clearly demonstrated a nonuniform stretch ratio distribution in the tissue under uniaxial loading. The rupture initiation regions had significantly higher stretch ratios (1.26 [1.15-1.40]) than the tissue average stretch ratio (1.11 [1.10-1.16]). No significant difference in collagen direction and dispersion was identified between the rupture regions and the rest of the tissue. The presented study forms an initial step towards gaining better insights into the characterization of local structural and mechanical fingerprints of fibrous plaque tissue in order to aid improved assessment of plaque rupture risk. Plaque rupture risk assessment, critical to prevent cardiovascular events, requires knowledge on local failure properties and structure of collagenous plaque tissue. Our current knowledge is unfortunately limited to tissue's overall ultimate failure properties with scarce information on collagen architecture. In this study, local failure properties and collagen architecture of fibrous plaque tissue were obtained. We found predominant circumferential alignment of collagen fibers with substantial local dispersion. The tissue showed nonuniform stretch distribution under uniaxial tensile loading, with high stretches at rupture spots. This study highlights the significance of local mechanical and structural assessment for better insights into plaque rupture and the potential use of local stretches as risk marker for plaque rupture for patient-specific clinical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Small vessel disease (SVD) widely exists in patients with acute coronary syndrome. However, the plaque characteristic of SVD has not been investigated. Methods: Optical coherence tomography (OCT) of culprit lesion was examined in 576 patients with STsegment elevation myocardial infarction (STEMI) and finally 404 patients with qualified images were analysed of plaque phenotypes and microstructure. The cohort was divided into three groups according to vessel diameters of culprit lesion which were measured by OCT. Major adverse cardiac events (MACEs) were recorded of each patient and compared among patients with different vessel diameters and plaque phenotypes. Results: Gender, age and body mass index (BMI) were significantly different among patients with different diameters of culprit vessels (98.4% vs. 85.7% vs.71.4%, p < 0.001; 40.0 ± 7.0 vs. 54.9 ± 6.6 vs. 68.9 ± 5.8, p < 0.001; 28.4 ± 4.0 vs. 25.8 ± 2.9 vs. 25.2 ± 3.0, p < 0.001, respectively). Moreover, patients with diameters of culprit lesion >3 mm presented with more incidence of plaque rupture and macrophage (57.7% vs. 42.1% vs. 46.2%, p = 0.015, 55.1% vs. 41.0% vs. 36.9%, p = 0.010). Total MACE did not differ among groups of different vessel diameters and plaque phenotypes. Conclusions: Vessel size of culprit lesion is significantly associated with plaque phenotype in patients with STEMI. However, patients with different diameters and plaque phenotypes showed no significant difference of clinical outcomes. [ABSTRACT FROM AUTHOR]

Kazuhiro Shimizu,1 Mao Takahashi,1 Shuji Sato,1 Atsuhito Saiki,1 Daiji Nagayama,1,2 Takashi Hitsumoto,3 Akira Takahara,4 Kohji Shirai1,5 1Department of Internal Medicine, Toho University Sakura Medical Center, Sakura, Chiba, Japan; 2Department of Internal Medicine, Nagayama Clinic, Oyama, Tochigi, Japan; 3Hitsumoto Medical Clinic, Shimonoseki, Yamaguchi, Japan; 4Department of Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, Japan; 5Department of Internal Medicine, Seijinkai Mihama Hospital, Chiba, Chiba, JapanCorrespondence: Kazuhiro Shimizu, Department of Internal Medicine, Toho University Sakura Medical Center, 561-4 Shimoshizu, Sakura, Chiba, 285-8741, Japan, Tel +81-43-462-8811, Fax +81-43-462-8820, Email k432@sakura.med.toho-u.ac.jpAbstract: Predictive factors for vascular events have not been established. The vasculature of the atheroma is supplied by penetration of the vasa vasorum through the smooth muscle cell layer from the adventitia. Smooth muscle cell contraction induces compression of the vasa vasorum, resulting in ischemia in intimal atheromatous lesions. Cardio-ankle vascular index (CAVI) has become known as an index of arterial stiffness of the arterial tree from the origin of the aorta to the ankle. CAVI reflects the progress of arteriosclerosis, and a rapid rise in CAVI indicates arterial smooth muscle cell contraction. We hypothesized that rapidly increased arterial stiffness evaluated by CAVI may be a predictor of impending cardiovascular events.Keywords: arterial stiffness, stress, plaque rupture, CAVI

The relationship between high wall shear stress (WSS) and plaque rupture (PR) in longitudinal and circumferential locations remains uncertain. Overall, 100 acute coronary syndrome patients whose culprit lesions had PR, documented by optical coherence tomography (OCT), were enrolled. Lesion-specific three-dimensional coronary artery models were created using OCT data. WSS was computed with computational fluid dynamics analysis. PR was classified into upstream-PR, minimum lumen area-PR, and downstream-PR according to the PR's longitudinal location, and into central-PR and lateral-PR according to the disrupted fibrous cap circumferential location. In the longitudinal 3-mm segmental analysis, multivariate analysis demonstrated that higher WSS in the upstream segment was independently associated with upstream-PR, and thinner fibrous cap was independently associated with downstream-PR. In the PR cross-sections, the PR region had a significantly higher average WSS than non-PR region. In the cross-sectional analysis, the in-lesion peak WSS was frequently observed in the lateral (66.7%) and central regions (70%) in lateral-PR and central-PR, respectively. Multivariate analysis demonstrated that the presence of in-lesion peak WSS at the lateral region, thinner broken fibrous cap, and larger lumen area were independently associated with lateral-PR, while the presence of in-lesion peak WSS at the central region and thicker broken fibrous cap were independently associated with central-PR. In conclusion, OCT-based WSS simulation revealed that high WSS might be related to the longitudinal and circumferential locations of PR. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is an intravascular imaging technique that uses near-infrared light. OCT provides high-resolution cross-sectional images of coronary arteries and enables tissue characterization of atherosclerotic plaques. OCT can identify plaque rupture, plaque erosion, and calcified nodule in culprit lesions of acute coronary syndrome. OCT can also detect important morphologic features of vulnerable plaques such as thin fibrous caps, large lipid cores, macrophages accumulation, intraplaque microvasculature, cholesterol crystals, healed plaques, and intraplaque hemorrhage. [ABSTRACT FROM AUTHOR]

Acute coronary syndrome (ACS) is the most severe form of ischemic heart disease. Although it is caused by atherosclerotic plaque thrombosis or nonatherosclerotic causes, its pathophysiological mechanism of ACS is not fully understood, and its concept is constantly updated and developed. At present, the main pathophysiological mechanisms include plaque rupture, plaque erosion, calcified nodules (CN) and non-atherosclerotic causes such as coronary vasospasm and myocardial bridging (MB). These mechanisms may overlap and coexist in some ACS patients. Therefore, the pathophysiological mechanism of ACS is complex, and is of great significance for the diagnosis and treatment of ACS. This review will discuss the pathophysiological mechanisms of ACS to provide new thoughts on the pathogenesis, diagnosis and treatment of ACS. [ABSTRACT FROM AUTHOR]

Background: Most acute coronary syndromes occur due to coronary thrombosis caused by plaque rupture (PR) and plaque erosion (PE). Precise in vivo differentiation between PR and PE is challenging for intravascular imaging. This study is the first to determine the diagnostic performance of the novel 60 MHz high-definition intravascular ultrasound (HD-IVUS) for differentiating atherosclerotic plaque morphology influenced by local hemodynamic flow in rabbits. This study evaluated the diagnostic performance of 60 MHz HD-IVUS in identifying thrombosis in rabbits. Methods: We established 60 rabbit models of atherosclerosis with left common carotid artery (LCCA) stenosis and 30 FeCl3-induced LCCA thrombosis. Intravascular imaging was assessed with 60 MHz HD-IVUS and fourier-domain optical coherence tomography (FD-OCT). The present study investigated the diagnostic accuracy of 60 MHz HD-IVUS for PR and PE, as well as thrombosis, using OCT-diagnosis as a standard reference. Results: 60 MHz HD-IVUS for identifying atherosclerotic plaque morphology using plaque cavity and minor intimal irregularities showed high sensitivity and specificity; 92.0 and 90.0% for identifying OCT-defined PR, and 80.0 and 70.0% for OCT-defined PE, respectively. In a rabbit thrombus model, 60 MHz HD-IVUS showed high sensitivity (88.0%) and specificity (80.0%) in identifying OCT-defined thrombosis. Conclusions: 60 MHz HD-IVUS can accurately identify PR and thrombosis. Further studies should confirm the clinical value of this novel technique in PE diagnosis. [ABSTRACT FROM AUTHOR]

The fibrous cap is formed by smooth muscle cells that accumulate beneath the plaque endothelium. Cap rupture is the main cause of coronary thrombosis, leading to infarction and sudden cardiac death. Therefore, the qualities of the cap are primary determinants of the clinical outcome of coronary and carotid atherosclerosis. In this mini-review, we discuss current knowledge about the formation of the fibrous cap, including cell recruitment, clonal expansion, and central molecular signaling pathways. We also examine the differences between mouse and human fibrous caps and explore the impact of anti-atherosclerotic therapies on the state of the fibrous cap. We propose that the cap should be understood as a neo-media to substitute for the original media that becomes separated from the surface endothelium during atherogenesis and that embryonic pathways involved in the development of the arteria media contribute to cap formation.

Background A previous coronary computed tomography (CT) angiographic study failed to discriminate optical coherence tomography‐defined intact fibrous cap culprit lesions (IFC group) from those with ruptured fibrous caps (RFC group) in patients with coronary artery disease. This study aimed to evaluate the diagnostic efficacy of preprocedural coronary CT imaging in identifying subsequently performed optical coherence tomography‐defined plaque rupture or erosion at culprit lesions in patients with non–ST‐segment–elevation acute myocardial infarction. Methods and Results This study used data from 2 recently published studies that tested the hypothesis that coronary CT angiography (CCTA) before percutaneous coronary intervention may provide diagnostic information on the high‐risk atherosclerotic burden in patients with non–ST‐segment–elevation acute myocardial infarction. In the analysis of 186 patients, optical coherence tomography identified 106 RFC plaques and 80 IFC plaques as the culprit lesions. On CT, the prevalence of low‐attenuation plaque, positive remodeling, napkin‐ring sign, and spotty calcification were all significantly lower in the IFC group. The culprit vessel pericoronary adipose tissue inflammation and coronary artery calcium scores were significantly lower in the IFC group than in the RFC group. The absence of low‐attenuation plaque, napkin‐ring sign, zero coronary artery calcium, and low pericoronary adipose tissue inflammation were independent predictors of IFC. When stratified into 5 subgroups according to the number of these 4 CT factors, the prevalence of IFC was 8.3%, 20.8%, 44.6%, 75.6%, and 100% (P

BackgroundPlaque rupture and acute atherothrombosis, resulting from continued progression of atherosclerotic plaques (APs), are major contributors to acute clinical events such as stroke or myocardial infarction. This article aimed to explore the gene signatures and potential molecular mechanisms in the progression and instability of APs and to identify novel biomarkers and interventional targets for AP rupture.MethodsThe microarray data were downloaded from the Gene Expression Omnibus (GEO) database and grouped into discovery and validation cohorts. In the discovery cohort, Weighted Gene Co-Expression Network Analysis was performed for finding co-expression modules, and the Metascape database was used to perform functional enrichment analysis. Differential Expression Genes analysis subsequently was performed in the validation cohort for verification of the obtained results. Common genes were introduced into Metascape database for protein–protein interaction and functional enrichment analysis. We constructed the miRNAs–mRNAs network with the hub genes. Moreover, gene expression profiles of peripheral blood mononuclear cells (PBMCs) from peripheral blood of patients with plaque rupture were analyzed by high-throughput sequencing, and the diagnostic power of hub genes was verified by receiver operating characteristic (ROC) analysis.ResultsIn the discovery cohort, the brown module in GSE28829 and the turquoise module in GSE163154 were the most significant co-expression modules. Functional enrichment analysis of shared genes suggested that “Neutrophil degranulation” was the most significantly enriched pathway. These conclusions were also demonstrated by the validation cohort. A total of 16 hub genes were identified. The miRNA–mRNA network revealed that hsa-miR-665 and hsa-miR-512-3p might regulate the “Neutrophil degranulation” pathway through PLAU and SIRPA, which might play a significant role in AP progression and instability. Five hub genes, including PLAUR, FCER1G, PLAU, ITGB2, and SLC2A5, showed significantly increased expression in PBMCs from patients with plaque rupture compared with controls. ROC analysis finally identified three hub genes PLAUR, FCER1G, and PLAU that could effectively distinguish patients with APs rupture from controls.ConclusionsThe present study demonstrated that the “neutrophil degranulation” signaling pathways and identified novel mRNA and miRNA candidates are closely associated with plaque progression and instability. The hub genes FCER1G, PLAUR, and PLAU may serve as biomarkers for the prospective prediction of AP rupture.

Wall shear stress (WSS) is involved in coronary artery plaque pathological mechanisms and modulation of gene expression. This study aims to provide a comprehensive haemodynamic and biological description of unstable (intact-fibrous-cap, IFC, and ruptured-fibrous-cap, RFC) and stable (chronic coronary syndrome, CCS) plaques and investigate any correlation between WSS and molecular pathways. We enrolled 24 CCS and 25 Non-ST Elevation Myocardial Infarction-ACS patients with IFC (n = 11) and RFC (n = 14) culprit lesions according to optical coherence tomography analysis. A real-time PCR primer array was performed on peripheral blood mononuclear cells for 17 different molecules whose expression is linked to WSS. Computational fluid dynamics simulations were performed in high-fidelity 3D-coronary artery anatomical models for three patients per group. A total of nine genes were significantly overexpressed in the unstable patients as compared to CCS patients, with no differences between IFC and RFC groups (GPX1, MMP1, MMP9, NOS3, PLA2G7, PI16, SOD1, TIMP1, and TFRC) while four displayed different levels between IFC and RFC groups (TNFα, ADAMTS13, EDN1, and LGALS8). A significantly higher WSS was observed in the RFC group (p < 0.001) compared to the two other groups. A significant correlation was observed between TNFα (p < 0.001), EDN1 (p = 0.036), and MMP9 (p = 0.005) and WSS values in the RFC group. Our data demonstrate that IFC and RFC plaques are subject to different WSS conditions and gene expressions, suggesting that WSS profiling may play an essential role in the plaque instability characterization with relevant diagnostic and therapeutic implications in the era of precision medicine. • Wall shear stress (WSS) is involved in coronary artery plaque pathological mechanisms and modulation of gene expression. • Different phenotypes of coronary artery plaques (intact fibrous cap and ruptured fibrous cap) are subject to different WSS and gene expression. • The combination of fluid-dynamic with biological profiling might help to characterize coronary artery plaque and to detect unstable ones. [ABSTRACT FROM AUTHOR]

Background: Patients with STEMI are postulated to have different culprit lesion morphology compared to NSTEMI. The use of OCT in ACS can help delineate lesion morphology. The aim of this systematic review was to analyze the available data on culprit plaque morphology in ACS patients. Methods: The available literature was systematically screened for studies on culprit lesion morphology in ACS patients. Data was extracted from the selected studies and analyzed for baseline characteristics as well as culprit lesion morphology on OCT. Lesion characteristics between STEMI and NSTEMI groups were compared. Results: A total of 32 studies were selected for the final analysis. The average age of the study population was 62.4 years. Majority of patients (66.6%) had STEMI on presentation. NSTEMI patients had a higher prevalence of diabetes compared to STEMI. Both STEMI and NSTEMI patients had similar prevalence of thin-cap fibroatheroma (44.9%). The mean fibrous cap thickness was 84.2 mm in the study. STEMI patients had higher prevalence of lipid plaques, macrophages and luminal thrombus as compared to NSTEMI patients. Plaque rupture was the predominant culprit lesion morphology in both STEMI and NSTEMI groups, with higher prevalence in STEMI patients. Plaque erosion was also more common in STEMI patients (34.4% vs 13.2%). Conclusion: Plaque rupture is the predominat culprit lesion morphology in both STEMI and NSTEMI patients, despite having differences in baseline characteristics. Use of OCT to determine plaque morphology in ACS patients can help guide management strategy in select cases. [PROSPERO CRD42021249742]. [ABSTRACT FROM AUTHOR]

A 70 year old left-handed man presented to his general practitioner with abnormal left arm movements, left hemianopia and loss of balance. He was found to have an isolated brachiocephalic artery aneurysm, measuring 3.5 cm, with associated plaque rupture, contributing to recurrent episodes of transient ischemic attack. He was discussed extensively by a multidisciplinary team. e concurrently had complete occlusion of the right internal carotid artery with distal reconstitution in its supraclinoid segment from collaterals. Stenting of the region would necessitate inappropriately covering the right vertebral artery which would further compromise intracerebral blood. Surgical intervention was deemed the only safe option and he was thus accepted for cardiothoracic surgery. Standard workup revealed left anterior descending artery stenosis. He underwent coronary artery bypass grafting, left atrial appendectomy and brachiocephalic artery resection with replacement with a interposition graft with 10 mm polytetrafluoroethylene graft. He recovered well. This case demonstrates the multi-disciplinary decision making in a rare cause of embolic stroke.

Xing Luo,1,2 Chen Zhao,1,2 Shengfang Wang,1,2 Haibo Jia,1,2 Bo Yu1,2 1Department of Cardiology, 2nd Affiliated Hospital of Harbin Medical University, Harbin, 150001, People’s Republic of China; 2Key Laboratory of Myocardial Ischemia, Ministry of Education, Harbin Medical University, Harbin, 150001, People’s Republic of ChinaCorrespondence: Haibo Jia; Bo Yu, Tel/Fax +86 0451 86297221 ; +86 0451 86297220, Email jhb101180@163.com; dryu_hmu@163.comBackground and Aims: Patients with plaque rupture (PR) present with different cardiovascular risks, clinical strategies, and outcomes from those with plaque erosion (PE). However, there are lack of noninvasive biomarkers to distinguish PE from PR.Methods: A prospective analysis of 382 patients with ST-segment elevation myocardial infarction (STEMI) was conducted. Of these patients, 262 and 120 presented with PR and PE, respectively. An additional 83 patients diagnosed with stable angina pectoris were enrolled as control group. Peripheral blood monocytes were collected pre-percutaneous coronary intervention and used to evaluate the mRNA expression of IL-4, IL-10, IL-1β, and TNF-α in all patients.Results: STEMI patients had higher IL-4, IL-10, IL-1β, and TNF-α expression than the control patients. The mRNA levels of IL-4, IL-1β, and TNF-α were significantly higher in PR patients than PE; however, no significant difference was observed in IL-10 between PE and PR. The areas under the receiver-operating characteristic curves for IL-4, IL-1β, and TNF-α for PR versus PE were 0.685, 0.747, and 0.895, respectively. At the cut-off value of 2.52, TNF-α demonstrated a sensitivity of 70.61% and specificity of 93.33% for discriminating PR from PE patients. When added to the model of established clinical risk factors, TNF-α significantly improved the predictive accuracy of PR. Multivariable logistic regression analysis indicated that TNF-α mRNA level was independently associated with PR (odds ratio, 3.09; 95% confidence interval, 2.29– 4.16; p < 0.001).Conclusion: The inflammatory response of peripheral blood mononuclear cells in patients with PR was higher than that in patients with PE. TNF-α may be a potential biomarker for predicting PR that could facilitate risk stratification and management in STEMI patients.Graphical Abstract: Keywords: acute coronary syndrome, plaque rupture, plaque erosion, inflammation, TNF-&#x03B1

Atherosclerosis is a chronic vascular disease. Its prevalence increases with aging. However, atherosclerosis may also affect young subjects without significant exposure to the classical risk factors. Recent evidence indicates clonal hematopoiesis of indeterminate potential (CHIP) as a novel cardiovascular risk factor that should be suspected in young patients. CHIP represents a link between impaired bone marrow and atherosclerosis. Atherosclerosis may present with an acute symptomatic manifestation or subclinical events that favor plaque growth. The outcome of a plaque relies on a balance of innate and environmental factors. These factors can influence the processes that initiate and propagate acute plaque destabilization leading to intraluminal thrombus formation or subclinical vessel healing. Thirty years ago, the first autopsy study revealed that coronary plaques can undergo rupture even in subjects without a known cardiovascular history. Nowadays, cardiac magnetic resonance studies demonstrate that this phenomenon is not rare. Myocardial infarction is mainly due to plaque rupture and plaque erosion that have different pathophysiological mechanisms. Plaque erosion carries a better prognosis as compared to plaque rupture. Thus, a tailored conservative treatment has been proposed and some studies demonstrated it to be safe. On the contrary, plaque rupture is typically associated with inflammation and anti-inflammatory treatments have been proposed in response to persistently elevate biomarkers of systemic inflammation. In conclusion, atherosclerosis may present in different forms or phenotypes. Vulnerable patient phenotypes, identified by using intravascular imaging techniques, biomarkers, or even genetic analyses, are characterized by distinctive pathophysiological mechanisms. These different phenotypes merit tailored management. • Atherosclerosis can lead to acute symptomatic manifestation such as myocardial infarction or subclinical events. • CHIP represents a link between impaired bone marrow and atherosclerosis and represents a novel cardiovascular risk factor. • Plaque rupture and plaque erosion have different pathophysiological mechanisms as well as distinctive associations with risk factors. • Plaque rupture/erosion can favor plaque growth without acute symptomatic manifestation. This phenomenon is called healing process and can be detected in vivo. • Different plaque phenotypes and distinctive mechanisms deserve tailored management. [ABSTRACT FROM AUTHOR]

Background: High plasma levels of Lp(a) are associated with a worse prognosis in patients with coronary artery disease. The aim of the present study is to clarify the association between high lipoprotein a [Lp(a)] levels and vulnerable characteristics of nonculprit plaques in patients with acute coronary syndrome (ACS). Methods: A total of 185 consecutive patients with ACS who underwent optical coherence tomography imaging of nonculprit plaques in the culprit vessels were enrolled. Patients were divided into the high Lp(a) group (≥30 mg/dL; 50 nonculprit plaques in 49 patients) or the low Lp(a) group (

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Altered plasma sphingosine-1-phosphate (S1P) concentrations are associated with clinical manifestations of atherosclerosis. However, whether long-term elevation of endogenous S1P is pro- or anti-atherogenic remains unclear. Here, we addressed the impact of permanently high S1P levels on atherosclerosis in cholesterol-fed apolipoprotein E-deficient (ApoE−/−) mice over 12 weeks. This was achieved by pharmacological inhibition of the S1P-degrading enzyme S1P lyase with 4-deoxypyridoxine (DOP). DOP treatment dramatically accelerated atherosclerosis development, propagated predominantly unstable plaque phenotypes, and resulted in frequent plaque rupture with atherothrombosis. Macrophages from S1P lyase-inhibited or genetically deficient mice had a defect in cholesterol efflux to apolipoprotein A-I that was accompanied by profoundly downregulated cholesterol transporters ATP-binding cassette transporters ABCA1 and ABCG1. This was dependent on S1P signaling through S1PR3 and resulted in dramatically enhanced atherosclerosis in ApoE−/−/S1PR3−/− mice, where DOP treatment had no additional effect. Thus, high endogenous S1P levels promote atherosclerosis, compromise cholesterol efflux, and cause genuine plaque rupture. [ABSTRACT FROM AUTHOR]

Plaque rupture (PR), characterized by a disruption of the fibrous cap of lipid-rich plaques, is the major etiology of ST-segment elevation myocardial infarction (STEMI). Dyslipidemia is a well-known risk factor for PR. Nonetheless, the impact of detailed atherogenic lipid profiles, including small dense low-density lipoprotein cholesterol (sd-LDL-C) and triglyceride-rich lipoproteins (TRLs), on PR has not yet been investigated. To elucidate the impact of sd-LDL-C and TRL levels on PR in patients with STEMI using optical coherence tomography (OCT). A total of 106 consecutive statin-naive patients with STEMI were enrolled. The PR in culprit lesions was assessed on pre-intervention OCT images, and serum samples were collected immediately before coronary angiography. Sd-LDL-C was directly measured using a homogeneous assay. TRL-cholesterol (TRL-C) was estimated by subtracting the LDL-C level from the non-high-density lipoprotein cholesterol level. Clinical characteristics and lipid profiles were compared between the PR and intact fibrous cap (IFC). No difference in LDL-C levels was observed between the PR (n=64) and IFC (n=42) groups (120.0 mg/dL vs. 129.5 mg/dL, p=0.97); however, sd-LDL-C levels were significantly higher in the PR group (38.9 mg/dL vs. 32.4 mg/dL, p=0.04). Similarly, the PR group had higher TRL-C (24.0 mg/dL vs. 18.0 mg/dL, p=0.01) and triglyceride (130.0 mg/dL vs. 100.3 mg/dL, p=0.03) levels than the IFC group. Multivariate logistic regression analysis showed that sd-LDL-C was an independent factor determining PR (odds ratio, 1.53 per 10 mg/dL; p=0.04). Only sd-LDL-C levels were significantly associated with PR in culprit lesions in patients with STEMI. [Display omitted] [ABSTRACT FROM AUTHOR]

Aims: Complete non-culprit (NC) revascularization may help reduce recurrent events after NSTEMI, especially if NC lesions would harbor high-risk plaque features similar to STEMI. The study aimed to assess differences in fractional flow reserve (FFR)-negative NC plaque morphology in patients presenting with NSTEMI versus STEMI and assess the association of high-risk plaque morphology and clinical outcome., Methods and Results: In the prospective PECTUS-obs study, 438 patients presenting with myocardial infarction (MI) underwent optical coherence tomography (OCT) of all FFR-negative intermediate NC lesions. The primary endpoint was the occurrence of major adverse cardiovascular events (MACE, all-cause mortality, non-fatal MI or unplanned revascularization) at two-year follow-up. Four hundred and twenty patients had at least one analyzable OCT, including 203 (48.3%) with NSTEMI and 217 (51.7%) with STEMI. The prevalence of high-risk plaques (HRP), including thin-cap fibroatheromas (TCFA), plaque rupture and thrombus, was comparable between groups. MACE occurred in 29 (14.3%) NSTEMI patients and 16 (7.4%) STEMI patients (Punivariable=0.025 and Pmultivariable=0.270). Incidence of MACE was numerically higher among patients with HRP, irrespective of the clinical presentation at index (Pinteraction=0.684). Among high-risk plaque criteria, plaque rupture was associated with MACE in both NSTEMI (p<0.001) and STEMI (p=0.020)., Conclusion: Presence of NC HRP is comparable between NSTEMI and STEMI and leads to numerically higher event rates in both. These results call for additional research on complete revascularization in NSTEMI and treatment of HRP., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)