Pathology of the Vulnerable Plaque

Clinical impact of deep learning-derived intravascular ultrasound characteristics in patients with deferred coronary artery

Prognostic markers for long-term outcomes are lacking in patients with deferred (nonculprit) coronary artery lesions. This study aimed to identify the morphological criteria for predicting adverse outcomes and validate their clinical impact. Using deep learning models, we extracted geometrical parameters and maximal attenuation (or calcium) burden index (ABI-max or CBI-max) from the intravascular ultrasound (IVUS) images of nonculprit vessels in 1115 patients. The endpoints included cardiac death, myocardial infarction, and target vessel revascularization of nonculprit vessel. Cardiac death occurred in 27 (2.4 %) patients at 3 years and 39 (3.5 %) patients at 5 years. At 5 years, the cardiac death-free survival rate was significantly lower with ABP-max ≥11.37 % vs. < 11.37 % (90.0 % vs. 98.7 %), CBI-max ≥13.40 % vs. < 13.40 % (92.8 % vs. 98.4 %), and percent atheroma volume ≥ 51.35 % vs. < 51.35 % (94.0 % vs. 97.7) (all log-rank p < 0.001). The independent predictors of 5-year cardiovascular mortality were age (hazard ratio [HR] 1.21), female sex (HR 0.33), history of heart failure (HR 6.06), chronic kidney disease (HR 18.28), ABI-max (HR 1.04), and CBI-max (HR 1.05). The independent determinants of 5-year target vessel revascularization of nonculprit vessel were fractional flow reserve (HR 0.95 per 0.01 increase), minimal lumen area (HR 0.63), and plaque burden (HR 1.15). In patients with nonculprit coronary artery lesions, a large burden of attenuated or calcified plaques predicted cardiac mortality, while IVUS geometry was associated with repeat revascularization. Thus, deep learning-based IVUS analysis of the whole target vessel may help clinicians identify high-risk lesions.

Management of vulnerable patient phenotypes and acute coronary syndrome mechanisms

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.

Spatial Transcriptomic Approach to Understanding Coronary Atherosclerotic Plaque Stability

BACKGROUND

Coronary atherosclerotic plaques susceptible to acute coronary syndrome have traditionally been characterized by their surrounding cellular architecture. However, with the advent of intravascular imaging, novel mechanisms of coronary thrombosis have emerged, challenging our contemporary understanding of acute coronary syndrome. These intriguing findings underscore the necessity for a precise molecular definition of plaque stability. Considering this, our study aimed to investigate the vascular microenvironment in patients with stable and unstable plaques using spatial transcriptomics.

METHODS

Autopsy-derived coronary arteries were preserved and categorized by plaque stability (n=5 patients per group). We utilized the GeoMx spatial profiling platform and Whole Transcriptome Atlas to link crucial histological morphology markers in coronary lesions with differential gene expression in specific regions of interest, thereby mapping the vascular transcriptome. This innovative approach allowed us to conduct cell morphological and spatially resolved transcriptional profiling of atherosclerotic plaques while preserving crucial intercellular signaling.

RESULTS

We observed intriguing spatial and cell-specific transcriptional patterns in stable and unstable atherosclerotic plaques, showcasing regional variations within the intima and media. These regions exhibited differential expression of proinflammatory molecules (eg, IFN-γ [interferon-γ], MHC [major histocompatibility complex] class II, proinflammatory cytokines) and prothrombotic signaling pathways. By using lineage tracing through spatial deconvolution of intimal CD68+ (cluster of differentiation 68) cells, we characterized unique, intraplaque subpopulations originating from endothelial, smooth muscle, and myeloid lineages with distinct regional locations associated with plaque instability. In addition, unique transcriptional signatures were observed in vascular smooth muscle and CD68+ cells among plaques exhibiting coronary calcification.

CONCLUSIONS

Our study illuminates distinct cell-specific and regional transcriptional alterations present in unstable plaques. Furthermore, we characterize spatially resolved, in situ evidence supporting cellular transdifferentiation and intraplaque plasticity as significant contributors to plaque instability in human coronary atherosclerosis. Our results provide a powerful resource for the identification of novel mediators of acute coronary syndrome, opening new avenues for preventative and therapeutic treatments.

Targeting senescent cells in atherosclerosis: Pathways to novel therapies

Targeting senescent cells has recently emerged as a promising strategy for treating age-related diseases, such as atherosclerosis, which significantly contributes to global cardiovascular morbidity and mortality. This review elucidates the role of senescent cells in the development of atherosclerosis, including persistently damaging DNA, inducing oxidative stress and secreting pro-inflammatory factors known as the senescence-associated secretory phenotype. Therapeutic approaches targeting senescent cells to mitigate atherosclerosis are summarized in this review, which include the development of senotherapeutics and immunotherapies. These therapies are designed to either remove these cells or suppress their deleterious effects. These emerging therapies hold potential to decelerate or even alleviate the progression of AS, paving the way for new avenues in cardiovascular research and treatment.

Decoding marker genes and immune landscape of unstable carotid plaques from cellular senescence

Recently, cellular senescence-induced unstable carotid plaques have gained increasing attention. In this study, we utilized bioinformatics and machine learning methods to investigate the correlation between cellular senescence and the pathological mechanisms of unstable carotid plaques. Our aim was to elucidate the causes of unstable carotid plaque progression and identify new therapeutic strategies. First, differential expression analysis was performed on the test set GSE43292 to identify differentially expressed genes (DEGs) between the unstable plaque group and the control group. These DEGs were intersected with cellular senescence-associated genes to obtain 40 cellular senescence-associated DEGs. Subsequently, key genes were then identified through weighted gene co-expression network analysis, random forest, Recursive Feature Elimination for Support Vector Machines algorithm and cytoHubba plugin. The intersection yielded 3 CSA-signature genes, which were validated in the external validation set GSE163154. Additionally, we assessed the relationship between these CSA-signature genes and the immune landscape of the unstable plaque group. This study suggests that cellular senescence may play an important role in the progression mechanism of unstable plaques and is closely related to the influence of the immune microenvironment. Our research lays the foundation for studying the progression mechanism of unstable carotid plaques and provides some reference for targeted therapy.

Advanced Applications of Nanomaterials in Atherosclerosis Diagnosis and Treatment: Challenges and Future Prospects

Atherosclerosis-induced coronary artery disease is a major cause of cardiovascular mortality. Clinically, conservative treatment strategies for atherosclerosis still focus on lifestyle interventions and the use of lipid-lowering and anticoagulant medications. Despite achieving some therapeutic effects, these approaches are limited by low bioavailability, long intervention periods, and significant side effects. With the advancement of nanotechnology, nanomaterials have demonstrated extraordinary potential in the biomedical field. Their excellent biocompatibility, surface modifiability, and high targeting capability not only enable efficient diagnosis of plaque progression but also allow precise drug delivery within atherosclerotic plaques, significantly enhancing drug bioavailability and reducing systemic side effects. Here, we systematically review the current research progress of nanomaterials in the field of atherosclerosis to summarize not only the types of nanomaterials but also their applications in both the diagnosis and treatment of atherosclerosis. Notably, in the context of plaque therapy, we provide a comprehensive overview of current nanomaterial applications based on their targeted therapeutic systems for different cell types within plaques. Additionally, we address the persistent challenge of clinical translation of nanomaterials by summarizing current issues and providing directions for innovation and improvement in nanomaterial design. Overall, we believe that this review systematically summarizes the applications and challenges of biomedical nanomaterials in atherosclerosis diagnosis and therapy, thereby offering insights and references for the development of therapeutic materials for atherosclerosis.

Serial Optical Coherence Tomography Assessment of Coronary Atherosclerosis and Long-Term Clinical Outcomes

BACKGROUND

The impact of high-risk coronary artery plaques identified using optical coherence tomography on late luminal narrowing and clinical events remains poorly understood.

METHODS AND RESULTS

This multicenter prospective study included 176 patients who underwent percutaneous coronary intervention and serial optical coherence tomography at baseline and 1-year follow-up to investigate nontarget regions with angiographically intermediate stenosis. At 1 year after percutaneous coronary intervention, the coronary artery lumen area decreased significantly from 6.06 (95% CI, 5.60-6.53) mm2 to 5.88 (95% CI, 5.41-6.35) mm2 (difference, -0.18; 95% CI, -0.22 to -0.14 mm2; P<0.001), particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. The prevalence of fibroatheroma decreased from 38% to 36% (P<0.001), whereas calcified plaque increased from 31% to 34% (P<0.001), accompanied by a significant increase in calcium thickness and angle. Diabetes and current smoking habits were independently associated with increasing calcium prevalence. Patients with thin-cap fibroatheroma had a significantly higher 3-year risk of ischemia-driven nontarget vessel revascularization (hazard ratio, 2.42 [95% CI, 1.03-5.71]; P=0.04), primarily due to revascularization in the imaged region. No significant association was observed between coronary artery calcium prevalence and clinical outcomes within 3 years.

CONCLUSIONS

The coronary artery lumen area significantly decreased over a 1-year interval, particularly in thin-cap fibroatheromas, thick-cap fibroatheromas, mixed plaques, and fibrous plaques. Although thin-cap fibroatheroma prevalence was associated with higher risk of ischemia-driven nontarget vessel revascularization, no significant association was noted between coronary artery calcium prevalence and clinical outcomes within 3 years. The interaction between calcium progression and long-term clinical events necessitates further investigation.

REGISTRATION

URL: https://www.umin.ac.jp/ctr/; Unique Identifier: UMIN000031937.

Predictive models for cholesterol crystals and plaque vulnerability in acute myocardial infarction: Insights from an optical coherence tomography study

BACKGROUND

Cholesterol crystals (CCs) are recognized as a risk factor for vulnerable atherosclerotic plaque rupture (PR) and major adverse cardiovascular events. However, their predictive factors and association with plaque vulnerability in patients with acute myocardial infarction (AMI) remain insufficiently explored. Therefore, This study aims to investigate the association between CCs and plaque vulnerability in culprit lesions of AMI patients, identify the factors influencing CCs formation, and develop a predictive model for CCs.

METHODS

A total of 431 culprit lesions from AMI patients who underwent pre-intervention optical coherence tomography (OCT) imaging were analyzed. Patients were divided into groups based on the presence or absence of CCs and PR. The relationship between CCs and plaque vulnerability was evaluated. A risk nomogram for predicting CCs was developed using the least absolute shrinkage and selection operator and logistic regression analysis.

RESULTS

CCs were identified in 64.5 % of patients with AMI. The presence of CCs was associated with a higher prevalence of vulnerable plaque features, such as thin-cap fibroatheroma (TCFA), PR, macrophage infiltration, neovascularization, calcification, and thrombus, compared to patients without CCs. The CCs model demonstrated an area under the curve (AUC) of 0.676 for predicting PR. Incorporating CCs into the TCFA model (AUC = 0.656) significantly enhanced predictive accuracy, with a net reclassification improvement index of 0.462 (95 % confidence interval [CI]: 0.263-0.661, p < 0.001) and an integrated discrimination improvement index of 0.031 (95 % CI: 0.013-0.048, p = 0.001). Multivariate regression analysis identified the atherogenic index of plasma (odds ratio [OR] = 2.417), TCFA (OR = 1.759), macrophage infiltration (OR = 3.863), neovascularization (OR = 2.697), calcification (OR = 1.860), and thrombus (OR = 2.430) as independent risk factors for CCs formation. The comprehensive model incorporating these factors exhibited reasonable discriminatory ability, with an AUC of 0.766 (95 % CI: 0.717-0.815) in the training set and 0.753 (95 % CI: 0.704-0.802) in the internal validation set, reflecting good calibration. Decision curve analysis suggested that the model has potential clinical utility within a threshold probability range of approximately 18 % to 85 %.

CONCLUSIONS

CCs were associated with plaque vulnerability in the culprit lesions of AMI patients. Additionally, this study identified key factors influencing CCs formation and developed a predictive model with potential clinical applicability.

The LDL cumulative exposure hypothesis: evidence and practical applications

The trapping of LDL and other apolipoprotein B-containing lipoproteins within the artery wall causes atherosclerosis. As more LDL becomes trapped within the artery wall over time, the atherosclerotic plaque burden gradually increases, raising the risk of an acute cardiovascular event. Therefore, the biological effect of LDL on the risk of atherosclerotic cardiovascular disease (ASCVD) depends on both the magnitude and duration of exposure. Maintaining low levels of LDL-cholesterol (LDL-C) over time decreases the number of LDL particles trapped within the artery wall, slows the progression of atherosclerosis and, by delaying the age at which mature atherosclerotic plaques develop, substantially reduces the lifetime risk of ASCVD events. Summing LDL-C measurements over time to calculate cumulative exposure to LDL generates a unique biomarker that captures both the magnitude and duration of exposure, which facilitates the estimation of the absolute risk of having an acute cardiovascular event at any point in time. Titrating LDL-C lowering to keep cumulative exposure to LDL below the threshold at which acute cardiovascular events occur can effectively prevent ASCVD. In this Review, we provide the first comprehensive overview of how the LDL cumulative exposure hypothesis can guide the prevention of ASCVD. We also discuss the benefits of maintaining lower LDL-C levels over time and how this knowledge can be used to inform clinical practice guidelines as well as to design novel primary prevention trials and ASCVD prevention programmes.

Increased Piezo1 expression in myofibroblasts in patients with symptomatic carotid atherosclerotic plaques undergoing carotid endarterectomy: A pilot study

OBJECTIVES

We aimed to investigate Piezo1 expression in myofibroblasts in symptomatic and asymptomatic patients undergoing carotid endarterectomy and its relationship with atherosclerotic plaque formation.

METHODS

This cross-sectional study analyzed carotid plaques of 17 randomly selected patients who underwent carotid endarterectomy from May 2015 to August 2017. In total, 51 sections (the most stenotic lesion, and the sections 5-mm proximal and distal) stained with hematoxylin-eosin and elastica-Masson were examined. Immunohistochemistry was performed using antibodies to Piezo1. The Piezo1 score of a section was calculated semiquantitatively, averaged across 30 randomly selected myofibroblasts in the fibrous cap of the plaque.

RESULTS

Of 17 patients (mean age: 74.2 ± 7.1 years), 15 were men, 9 had diabetes mellitus, and 13 had hypertension. Symptomatic patients had higher mean Piezo1 score than asymptomatic patients (1.78 ± 0.23 vs 1.34 ± 0.17, p < .001). Univariate linear regression analyses suggested an association between plaque rupture, thin-cap fibroatheroma and microcalcifications and the Piezo1 score (p = .001, .008, and 0.003, respectively).

CONCLUSIONS

Increased Piezo1 expression of myofibroblasts may be associated with atherosclerotic carotid plaque instability. Further study is warranted to support this finding.

Optical Coherence Tomography in Myocardial Infarction Management: Enhancing Precision in Percutaneous Coronary Intervention

In acute myocardial infarction (AMI), the urgency of coronary revascularization through percutaneous coronary intervention (PCI) is paramount, offering notable advantages over pharmacologic treatment. However, the persistent risk of adverse events, including recurrent AMI and heart failure post-revascularization, underscores the necessity for enhanced strategies in managing coronary artery disease. Traditional angiography, while widely employed, presents significant limitations by providing only two-dimensional representations of complex three-dimensional vascular structures, hampering the accurate assessment of plaque characteristics and stenosis severity. Intravascular imaging, specifically optical coherence tomography (OCT), significantly addresses these limitations with superior spatial resolution compared to intravascular ultrasound (IVUS). Within the context of AMI, OCT serves dual purposes: as a diagnostic tool to accurately identify culprit lesions in ambiguous cases and as a guide for optimizing PCI procedures. Its capacity to differentiate between various mechanisms of acute coronary syndrome, such as plaque rupture and spontaneous coronary dissection, enhances its diagnostic potential. Furthermore, OCT facilitates precise lesion preparation, optimal stent sizing, and confirms stent deployment efficacy. Recent meta-analyses indicate that OCT-guided PCI markedly improves safety and efficacy in revascularization, subsequently decreasing the risks of mortality and complications. This review emphasizes the critical role of OCT in refining patient-specific therapeutic approaches, aligning with the principles of precision medicine to enhance clinical outcomes for individuals experiencing AMI.

Coronary atherosclerotic plaque characterization with silicon-based photon-counting computed tomography (CT): A simulation-based feasibility study

BACKGROUND

Recent photon-counting computed tomography (PCCT) development brings great opportunities for plaque characterization with much-improved spatial resolution and spectral imaging capability. While existing coronary plaque PCCT imaging results are based on CZT- or CdTe-materials detectors, deep-silicon photon-counting detectors offer unique performance characteristics and promise distinct imaging capabilities.

PURPOSE

This study aims to numerically investigate the feasibility of characterizing plaques with a deep-silicon PCCT scanner and to demonstrate its potential performance advantages over traditional CT scanners using energy-integrating detectors (EID).

METHODS

We conducted a systematic simulation study of a deep-silicon PCCT scanner using a newly developed digital plaque phantom with clinically relevant geometrical and chemical properties. Through qualitative and quantitative evaluations, this study investigates the effects of spatial resolution, noise, and motion artifacts on plaque imaging.

RESULTS

Noise-free simulations indicated that PCCT imaging could delineate the boundary of necrotic cores with a much finer resolution than EID-CT imaging, achieving a structural similarity index metric (SSIM) score of 0.970 and reducing the root mean squared error (RMSE) by two-thirds. Measuring necrotic core area errors were reduced from 91.5% to 24%, and fibrous cap thickness errors were reduced from 349.8% to 33.3%. In the presence of noise, the optimal reconstruction was achieved using 0.25 mm voxels and a soft reconstruction kernel, yielding the highest contrast-to-noise ratio (CNR) of 3.48 for necrotic core detection and the best image quality metrics among all choices. However, the ultrahigh resolution of PCCT increased sensitivity to motion artifacts, which could be mitigated by keeping residual motion amplitude below 0.4 mm.

CONCLUSIONS

The findings suggest that deep-silicon PCCT scanner can offer sufficient spatial resolution and tissue contrast for effective plaque characterization, potentially improving diagnostic accuracy in cardiovascular imaging, provided image noise and motion blur can be mitigated using advanced algorithms. This simulation study involves several simplifications, which may result in some idealized outcomes that do not directly translate to clinical practice. Further validation studies with physical scans are necessary and will be considered for future work.

Comparison of high-risk characteristics of non-culprit plaques in relation to plaque severity in acute coronary syndrome

INTRODUCTION

Patients with acute coronary syndrome (ACS) have high event rates related to non-culprit (NC) lesions, therefore plaque composition of these lesions is of great interest. Although marginal atherosclerotic lesions were studied extensively, more significant lesions might have more high-risk characteristics.

AIM

To compare differences in high-risk lesion characteristics between significant versus non-stenotic NC plaques in ACS and the discrepancies with chronic coronary syndrome (CCS) patients.

METHODS

Non-culprit vessels of 26 ACS patients with 26 angiographically significant lesions and 37 patients (17 ACS and 20 CCS) with 48 non-stenotic lesions were investigated with intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS). Overall, 74 segments of 30 mm length were analyzed in 1 mm intervals. External elastic lamina (EEM), plaque burden (PB), minimal luminal area (MLA), percent atheroma volume (PAV) and lipid core burden index maximum 4 mm (maxLCBI4mm) were determined for each segment.

RESULTS

Cardiovascular risk factors were similar in all groups. PB was higher and MLA smaller in significant non-culprit ACS lesions vs non-stenotic lesions: PB 73.5% (IQR 68.7-78.5) vs 59.2 (IQR 49.6-71.5), p = 0.003, MLA 3.0 mm2 (IQR 2.3-3.9) vs 4.0 mm2 (IQR 2.8-4.7). MaxLCBI4mm was similar 308.1 (±155.4) vs 287.8 (±165.7), p = 0.67. Among non-stenotic plaques, MaxLCBI4mm was comparable between ACS and CCS patients, 275.7 (±151.5) in CCS patients vs 287.8 (±165.7) in ACS patients, p = 0.79.

CONCLUSION

Although visually significant non-culprit lesions had a higher plaque burden compared to non-stenotic lesions, a significant relation between MaxLCBI4mm and hemodynamic significance of the plaques couldn't be established.

OCT-based comparative evaluation of culprit lesion morphology in very young versus older adult patients with STEMI

Background

The clinical and pathophysiological characteristics of coronary artery disease in very young adults are poorly described.

Aims

Using optical coherence tomography (OCT), we compared culprit lesion morphology in very young adult patients (≤35 years) versus older adult patients (>60 years) with ST-segment elevation myocardial infarction (STEMI).

Methods

Culprit lesion morphology was classified as plaque rupture, plaque erosion, or calcified nodule. Thrombus age was subclassified into acute (intraluminal thrombus with surface irregularity) or subacute (mostly mural thrombus with a smooth surface).

Results

A total of 61 patients who underwent thrombolysis within 24 hours from symptom onset were included, with 38 (59.7%) subjects ≤35 years and 23 (40.3%) subjects >60 years of age. As an underlying mechanism of STEMI thrombosis, plaque erosion was more common in very young patients (52.6% vs 21.7%; p=0.02) while plaque rupture was more common in elderly patients (65.2% vs 36.8%; p=0.03). Acute or subacute thrombus was identified in 68.9% (42/61) of patients, with red thrombus being more frequent in very young patients. In the entire patient cohort, acute thrombus was more frequent in plaque rupture compared with plaque erosion (62.0% vs 28.0%; p=0.01), whereas subacute thrombus was more common in plaque erosion versus plaque rupture (52.0% vs 10.3%; p=0.0008).

Conclusions

OCT showed that plaque erosion and plaque rupture were the most common underlying STEMI mechanisms in very young patients and older patients, respectively, and that subjects with plaque erosion had greater evidence of subacute thrombus.

Cyclophilin D induces necrotic core formation by mediating mitochondria-associated macrophage death in advanced atherosclerotic lesions

BACKGROUND AND AIMS

In advanced atherosclerotic lesions, macrophage deaths result in necrotic core formation and plaque vulnerability. Cyclophilin D (CypD) is a mitochondria-specific cyclophilin involved in the process of cell death after organ ischemia-reperfusion. However, the role of CypD in atherosclerosis, especially in necrotic core formation, is unknown. Therefore, this experiment aims to clarify the role of CypD in necrotic core formation.

METHODS

To clarify the specific role of CypD, encoded by Ppif in mice, apolipoprotein-E/CypD-double knockout (Apoe-/-Ppif-/-) mice were generated. These mice were fed a high-fat diet containing 0.15 % cholesterol for 24 weeks to accelerate atherosclerotic lesion development.

RESULTS

Deletion of CypD decreased the necrotic core size, accompanied by a reduction of macrophage apoptosis compared to control Apoe-/- mice. In RAW264.7 cells, siRNA-mediated knockdown of CypD attenuated the release of cytochrome c from the mitochondria to the cytosol induced by endoplasmic reticulum stress inducer thapsigargin. In addition, necroptosis, induced by TNF-α and caspase inhibitor, was attenuated by knockdown of CypD. Ly-6Chigh inflammatory monocytes in peripheral blood leukocytes and mRNA expression of Il1b in the aorta were decreased by deletion of CypD. In contrast, siRNA-mediated knockdown of CypD did not significantly decrease Il1b nor Ccl2 mRNA expression in RAW264.7 cells treated with LPS and IFN-γ, suggesting that inhibition of inflammation in vivo is likely due to decreased cell death in the atherosclerotic lesions rather than a direct action of CypD deletion on the macrophage.

CONCLUSIONS

These results indicate that CypD induces macrophage death and mediates necrotic core formation in advanced atherosclerotic lesions. CypD could be a novel therapeutic target for treating atherosclerotic vascular diseases.

Prognostic implications of pre-transcatheter aortic valve replacement computed tomography-derived coronary plaque characteristics and stenosis severity

OBJECTIVES

The study aimed to investigate the prognostic value of pre-transcatheter aortic valve replacement (TAVR) computed tomography angiography (CTA) in assessing physiological stenosis severity (CTA-derived fractional flow reserve (CT-FFR)) and high-risk plaque characteristics (HRPC).

MATERIALS AND METHODS

Among TAVR patients who underwent pre-procedure CTA, the presence and number of HRPCs (minimum lumen area of < 4 mm2, plaque burden ≥ 70%, low-attenuating plaques, positive remodeling, napkin-ring sign, or spotty calcification) as well as CT-FFR were assessed. The risk of vessel-oriented composite outcome (VOCO, a composite of vessel-related ischemia-driven revascularization, vessel-related myocardial infarction, or cardiac death) was compared according to the number of HRPC and CT-FFR categories.

RESULTS

Four hundred and twenty-seven patients (68.4% were male) with 1072 vessels were included. Their mean age was 70.6 ± 10.6 years. Vessels with low CT-FFR (≤ 0.80) (41.7% vs. 15.8%, adjusted hazard ratio (HRadj) 1.96; 95% confidence interval (CI): 1.28-2.96; p = 0.001) or lesions with ≥ 3 HRPC (38.7% vs. 16.0%, HRadj 1.81; 95%CI 1.20-2.71; p = 0.005) demonstrated higher VOCO risk. In the CT-FFR (> 0.80) group, lesions with ≥ 3 HRPC showed a significantly higher risk of VOCO than those with < 3 HRPC (34.7% vs. 13.0%; HRadj 2.04; 95%CI 1.18-3.52; p = 0.011). However, this relative increase in risk was not observed in vessels with positive CT-FFR (≤ 0.80).

CONCLUSIONS

In TAVR candidates, both CT-FFR and the presence of ≥ 3 HRPC were associated with an increased risk of adverse clinical events. However, the value of HRPC differed with the CT-FFR category, with more incremental predictability among vessels with negative CT-FFR but not among vessels with positive CT-FFR.

CLINICAL RELEVANCE STATEMENT

In transcatheter aortic valve replacement (TAVR) candidates, pre-TAVR CTA provided the opportunity to assess coronary physiological stenosis severity and high-risk plaque characteristics, both of which are associated with worse clinical outcomes.

KEY POINTS

• The current study investigated the prognostic value of coronary physiology significance and plaque characteristics in transcatheter aortic valve replacement patients. • The combination of coronary plaque vulnerability and physiological significance showed improved accuracy in predicting clinical outcomes in transcatheter aortic valve replacement patients. • Pre-transcatheter aortic valve replacement CT can be a one-stop-shop tool for coronary assessments in clinical practice.

The clinical relevance of the reversal of coronary atherosclerotic plaque

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of death globally despite advances in preventive therapies. Understanding of the initiation and progression of atherosclerosis, the interplay between lipoproteins, endothelial dysfunction, inflammation, and immune responses is critical to treating this disease. The development of vulnerable coronary plaques prone to thrombosis, can lead to acute coronary syndromes, for these reasons, the potential plaque stabilization and regression through pharmacological interventions, particularly lipid-lowering agents like statins and PCSK9 inhibitors is crucial. The imaging techniques such as intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and optical coherence tomography (OCT) play a key role in assessing plaque composition and guiding interventional therapeutic strategies. Clinical evidence supports the efficacy of intensive lipid-lowering therapy in inducing plaque regression, with studies demonstrating reductions in plaque volume and improvements in plaque morphology assessed by IVUS, OCT and NIRS. While pharmacological interventions show promise in promoting plaque regression and stabilization, their impact on long-term cardiovascular events requires further investigation. Multimodality imaging and comprehensive outcome trials are proposed as essential tools for elucidating the relationship between plaque modification and clinical benefit in coronary atherosclerosis. The stabilization or regression of atherosclerotic plaque might serve as the phenomenon linking the reduction in LDL-C levels to the decrease in cardiovascular events. Overall, this review emphasizes the ongoing efforts to advance our understanding of ASCVD pathophysiology and optimize therapeutic approaches for improving patient outcomes.

Efficient and Accurate 3D Thickness Measurement in Vessel Wall Imaging: Overcoming Limitations of 2D Approaches Using the Laplacian Method

The clinical significance of measuring vessel wall thickness is widely acknowledged. Recent advancements have enabled high-resolution 3D scans of arteries and precise segmentation of their lumens and outer walls; however, most existing methods for assessing vessel wall thickness are 2D. Despite being valuable, reproducibility and accuracy of 2D techniques depend on the extracted 2D slices. Additionally, these methods fail to fully account for variations in wall thickness in all dimensions. Furthermore, most existing approaches are difficult to be extended into 3D and their measurements lack spatial localization and are primarily confined to lumen boundaries. We advocate for a shift in perspective towards recognizing vessel wall thickness measurement as inherently a 3D challenge and propose adapting the Laplacian method as an outstanding alternative. The Laplacian method is implemented using convolutions, ensuring its efficient and rapid execution on deep learning platforms. Experiments using digital phantoms and vessel wall imaging data are conducted to showcase the accuracy, reproducibility, and localization capabilities of the proposed approach. The proposed method produce consistent outcomes that remain independent of centerlines and 2D slices. Notably, this approach is applicable in both 2D and 3D scenarios. It allows for voxel-wise quantification of wall thickness, enabling precise identification of wall volumes exhibiting abnormal wall thickness. Our research highlights the urgency of transitioning to 3D methodologies for vessel wall thickness measurement. Such a transition not only acknowledges the intricate spatial variations of vessel walls, but also opens doors to more accurate, localized, and insightful diagnostic insights.

Sex as a Predictor of Outcomes for Symptomatic Carotid Stenosis: A Comparative Analysis between CAS and CEA

PURPOSE

Reporting gender-related outcomes for symptomatic carotid lesion revascularization after both endarterectomy (CEA) and carotid artery stenting (CAS) procedures in an unselected group of patients treated by Italian Vascular Specialists.

MATERIAL AND METHODS

A retrospective study was conducted on patients presenting with recently symptomatic carotid stenosis treated by CAS and by CEA. The primary endpoint was the 30 days any stroke occurrence rate; secondary endpoints were technical success, occurrence of transient ischemic attack (TIA), acute myocardial infarction (AMI) and death. Demographic, clinical and procedural data were all noted in order to identify the outcome's determining factor.

RESULTS

A total of 265 patients (193 males and 72 females) were enrolled, and of these 134 (50.5%) underwent CEA and 131 CAS (49.5%). At 30 days, the overall new stroke rate was 3.4% (one fatal), and no TIA, AMI or deaths were observed. Among strokes, seven major and two minor strokes were reported, with six after CEA and three after CAS (p = 0.32; OR: 2; CI95%: 0.48-8.17). The timing of revascularization has been found to be slightly associated with new stroke occurrence: seven out nine strokes were observed in patients treated within 14 days from symptom onset (5.5% vs. 1.4%; p = 0.08, OR: 3.8, CI95%: 0.77-18.56). Lastly, female patients presented a significantly higher risk of post-operative stroke compared to male patients: 6.9% vs. 2.1% (p: 0.05; OR: 3.52; CI95%: 0.91-13.52).

CONCLUSIONS

Our experience seems to suggest that both CEA and CAS provide safe and effective results in treating patients presenting with symptomatic carotid stenosis. Regardless of the type of revascularization, female sex is an independent risk factor for stroke recurrence after treatment.

Advancements in risk stratification and management strategies in primary cardiovascular prevention

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality worldwide, highlighting the urgent need for advancements in risk assessment and management strategies. Although significant progress has been made recently, identifying and managing apparently healthy individuals at a higher risk of developing atherosclerosis and those with subclinical atherosclerosis still poses significant challenges. Traditional risk assessment tools have limitations in accurately predicting future events and fail to encompass the complexity of the atherosclerosis trajectory. In this review, we describe novel approaches in biomarkers, genetics, advanced imaging techniques, and artificial intelligence that have emerged to address this gap. Moreover, polygenic risk scores and imaging modalities such as coronary artery calcium scoring, and coronary computed tomography angiography offer promising avenues for enhancing primary cardiovascular risk stratification and personalised intervention strategies. On the other hand, interventions aiming against atherosclerosis development or promoting plaque regression have gained attention in primary ASCVD prevention. Therefore, the potential role of drugs like statins, ezetimibe, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, omega-3 fatty acids, antihypertensive agents, as well as glucose-lowering and anti-inflammatory drugs are also discussed. Since findings regarding the efficacy of these interventions vary, further research is still required to elucidate their mechanisms of action, optimize treatment regimens, and determine their long-term effects on ASCVD outcomes. In conclusion, advancements in strategies addressing atherosclerosis prevention and plaque regression present promising avenues for enhancing primary ASCVD prevention through personalised approaches tailored to individual risk profiles. Nevertheless, ongoing research efforts are imperative to refine these strategies further and maximise their effectiveness in safeguarding cardiovascular health.

Special Report on the Consensus QIBA Profile for Objective Analytical Validation of Non-calcified and High-risk Plaque and Other Biomarkers using Computed Tomography Angiography

RATIONALE AND OBJECTIVES

Evidence is building in support of the clinical utility of atherosclerotic plaque imaging by computed tomography angiography (CTA). There is increasing organized activity to embrace non-calcified plaque (NCP) as a formally defined biomarker for clinical trials, and high-risk plaque (HRP) for clinical care, as the most relevant measures for the field to advance and worthy of community efforts to validate. Yet the ability to assess the quantitative performance of any given specific solution to make these measurements or classifications is not available. Vendors use differing definitions, assessment metrics, and validation data sets to describe their offerings without clinician users having the capability to make objective assessments of accuracy and precision and how this affects diagnostic confidence.

MATERIALS AND METHODS

The QIBA Profile for Atherosclerosis Biomarkers by CTA was created by the Quantitative Imaging Biomarkers Alliance (QIBA) to improve objectivity and decrease the variability of noninvasive plaque phenotyping. The Profile provides claims on the accuracy and precision of plaque measures individually and when combined.

RESULTS

Individual plaque morphology measurements are evaluated in terms of bias (accuracy), slope (consistency of the bias across the measurement range, needed for measurements of change), and variability. The multiparametric plaque stability phenotype is evaluated in terms of agreement with expert pathologists. The Profile is intended for a broad audience, including those engaged in discovery science, clinical trials, and patient care.

CONCLUSION

This report provides a rationale and overview of the Profile claims and how to comply with the Profile in research and clinical practice.

SUMMARY STATEMENT

This article summarizes objective means to validate the analytical performance of non-calcified plaque (NCP), other emerging plaque morphology measurements, and multiparametric histology-defined high-risk plaque (HRP), as outlined in the QIBA Profile for Atherosclerosis Biomarkers by CTA.

A Review Paper on Optical Coherence Tomography Evaluation of Coronary Calcification Pattern: Is It Relevant Today?

The process of coronary calcification represents one of the numerous pathophysiological mechanisms involved in the atherosclerosis continuum. Optical coherence tomography (OCT) represents an ideal imaging modality to assess plaque components, especially calcium. Different calcification patterns have been contemporarily described in both early stages and advanced atherosclerosis. Microcalcifications and spotty calcifications correlate positively with macrophage burden and inflammatory markers and are more frequently found in the superficial layers of ruptured plaques in acute coronary syndrome patients. More compact, extensive calcification may reflect a later stage of the disease and was traditionally associated with plaque stability. Nevertheless, a small number of culprit coronary lesions demonstrates the presence of dense calcified plaques. The purpose of the current paper is to review the most recent OCT data on coronary calcification and the interrelation between calcification pattern and plaque vulnerability. How different calcified plaques influence treatment strategies and associated prognostic implications is of great interest.

Obesity and the obesity paradox in abdominal aortic aneurysm

Obesity, characterized by its complexity and heterogeneity, has emerged as a significant public health concern. Its association with increased incidence and mortality of cardiovascular diseases stems not only from its complications and comorbidities but also from the endocrine effects of adipose tissue. Abdominal aortic aneurysm (AAA), a chronic inflammatory condition, has been closely linked to obesity. Intriguingly, mild obesity appears to confer a protective effect against AAA mortality, whereas severe obesity and being underweight do not, giving rise to the concept of the "obesity paradox". This review aims to provide an overview of obesity and its paradoxical relationship with AAA, elucidate its underlying mechanisms, and discuss the importance of preoperative weight loss in severely obese patients with AAA.

Non-calcified plaque-based coronary stenosis grading in contrast enhanced CT

BACKGROUND

The high mortality rate associated with coronary heart disease has led to state-of-the-art non-invasive methods for cardiac diagnosis including computed tomography and magnetic resonance imaging. However, stenosis computation and clinical assessment of non-calcified plaques has been very challenging due to their ambiguous intensity response in CT i.e. a significant overlap with surrounding muscle tissues and blood. Accordingly, this research presents an approach for computation of coronary stenosis by investigating cross-sectional lumen behaviour along the length of 3D coronary segments.

METHODS

Non-calcified plaques are characterized by comparatively lower-intensity values with respect to the surrounding. Accordingly, segment-wise orthogonal volume was reconstructed in 3D space using the segmented coronary tree. Subsequently, the cross sectional volumetric data was investigated using proposed CNN-based plaque quantification model and subsequent stenosis grading in clinical context was performed. In the last step, plaque-affected orthogonal volume was further investigated by comparing vessel-wall thickness and lumen area obstruction w.r.t. expert-based annotations to validate the stenosis grading performance of model.

RESULTS

The experimental data consists of clinical CT images obtained from the Rotterdam CT repository leading to 600 coronary segments and subsequent 15786 cross-sectional images. According to the results, the proposed method quantified coronary vessel stenosis i.e. severity of the non-calcified plaque with an overall accuracy of 83%. Moreover, for individual grading, the proposed model show promising results with accuracy equal to 86%, 90% and 79% respectively for severe, moderate and mild stenosis. The stenosis grading performance of the proposed model was further validated by performing lumen-area versus wall-thickness analysis as per annotations of manual experts. The statistical results for lumen area analysis precisely correlates with the quantification performance of the model with a mean deviation of 5% only.

CONCLUSION

The overall results demonstrates capability of the proposed model to grade the vessel stenosis with reasonable accuracy and precision equivalent to human experts.

Increased incidence of napkin-ring sign plaques on cervicocerebral computed tomography angiography associated with the risk of acute ischemic stroke occurrence

OBJECTIVES

Carotid atherosclerosis plays an essential role in the occurrence of ischemic stroke. This study aimed to investigate whether a larger burden of napkin-ring sign (NRS) plaques on cervicocerebral computed tomography angiography (CTA) increased the risk of acute ischemic stroke (AIS).

METHODS

This retrospective, single-center, cross-sectional study enrolled patients with NRS plaques identified in the subclavian arteries, brachiocephalic trunk, carotid arterial system, and vertebrobasilar circulation on contrast-enhanced cervicocerebral CTA. Patients were divided into AIS and non-AIS groups based on imaging within 12 h of symptom onset. Univariate and multivariate logistic regression analyses were performed to determine the risk factor of AIS occurrence.

RESULTS

A total of 202 patients (66.72 years ± 8.97, 157 men) were evaluated. Plaques with NRS in each subject of the AIS group (N = 98) were significantly more prevalent than that in the control group (N = 104) (1.96 ± 1.17 vs 1.41 ± 0.62). In the AIS group, there were substantially more NRS plaques on the ipsilateral side than contralateral side (1.55 ± 0.90 vs. 0.41 ± 0.66). NRS located on the ipsilateral side of the AIS showed an area under the receiver curve (AUC) of 0.86 to identify ischemic stroke. NRS plaque amounts were an independent risk factor for AIS occurrence (odds ratio, 1.86) after adjusting for other factors.

CONCLUSIONS

Increased incidence of napkin-ring sign plaques on cervicocerebral CTA was positively associated with AIS occurrence, which could aid in detecting asymptomatic atherosclerotic patients at high risk of AIS in routine screening or emergency settings.

CLINICAL RELEVANCE STATEMENT

Napkin-ring sign plaque provides an important imaging target for estimating acute ischemic stroke risk and identifying high-risk patients in routine screening or emergency settings, so that timely anti-atherosclerotic therapy can be used for prevention.

KEY POINTS

• This cross-sectional study investigated the association between high-risk carotid artery plaques and acute ischemic stroke. • Increased incidence of napkin-ring sign plaques on cervicocerebral computed tomography angiography is positively associated with acute ischemic stroke occurrence. • Napkin-ring signs help identify risky patients prone to acute ischemic stroke to facilitate prevention.

Translocator Protein 18 kDa Tracer 18F-FDPA PET/CTA Imaging for the Evaluation of Inflammation in Vulnerable Plaques

Inflammation induced by activated macrophages within vulnerable atherosclerotic plaques (VAPs) constitutes a significant risk factor for plaque rupture. Translocator protein (TSPO) is highly expressed in activated macrophages. This study investigated the effectiveness of TSPO radiotracers, 18F-FDPA, in detecting VAPs and quantifying plaque inflammation in rabbits. 18 New Zealand rabbits were divided into 3 groups: sham group A, VAP model group B, and evolocumab treatment group C. 18F-FDPA PET/CTA imaging was performed at 12, 16, and 24 weeks in all groups. Optical coherence tomography (OCT) was performed on the abdominal aorta at 24 weeks. The VAP was defined through OCT images, and ex vivo aorta PET imaging was also performed at 24 weeks. The SUVmax and SUVmean of 18F-FDPA were measured on the target organ, and the target-to-background ratio (TBRmax) was calculated as SUVmax/SUVblood pool. The arterial sections of the isolated abdominal aorta were analyzed by HE staining, CD68 and TSPO immunofluorescence staining, and TSPO Western blot. The results showed that at 24 weeks, the plaque TBRmax of 18F-FDPA in group B was significantly higher than in groups A and C. Immunofluorescence staining of CD68 and TSPO, as well as Western blot, confirmed the increased expression of macrophages and TSPO in the corresponding regions of group B. HE staining revealed an increased presence of the lipid core, multiple foam cells, and inflammatory cell infiltration in the area with high 18F-FDPA uptake. This indicates a correlation between 18F-FDPA uptake, inflammation severity, and VAPs. The TSPO-targeted tracer 18F-FDPA shows specific uptake in macrophage-rich regions of atherosclerotic plaques, making it a valuable tool for assessing inflammation in VAPs.

Noninvasive Atherosclerotic Phenotyping: The Next Frontier into Understanding the Pathobiology of Coronary Artery Disease

PURPOSE OF REVIEW

Despite recent advances, coronary artery disease remains one of the leading causes of mortality worldwide. Noninvasive imaging allows atherosclerotic phenotyping by measurement of plaque burden, morphology, activity and inflammation, which has the potential to refine patient risk stratification and guide personalized therapy. This review describes the current and emerging roles of advanced noninvasive cardiovascular imaging methods for the assessment of coronary artery disease.

RECENT FINDINGS

Cardiac computed tomography enables comprehensive, noninvasive imaging of the coronary vasculature, and is used to assess luminal stenoses, coronary calcifications, and distinct adverse plaque characteristics, helping to identify patients prone to future events. Novel software tools, implementing artificial intelligence solutions, can automatically quantify and characterize atherosclerotic plaque from standard computed tomography datasets. These quantitative imaging biomarkers have been shown to improve patient risk stratification beyond clinical risk scores and current clinical interpretation of cardiac computed tomography. In addition, noninvasive molecular imaging in higher risk patients can be used to assess plaque activity and plaque thrombosis. Noninvasive imaging allows unique insight into the burden, morphology and activity of atherosclerotic coronary plaques. Such phenotyping of atherosclerosis can potentially improve individual patient risk prediction, and in the near future has the potential for clinical implementation.

Atherosclerotic plaque stabilization and regression: a review of clinical evidence

Atherosclerotic plaque results from a complex interplay between lipid deposition, inflammatory changes, cell migration and arterial wall injury. Over the past two decades, clinical trials utilizing invasive arterial imaging modalities, such as intravascular ultrasonography, have shown that reducing levels of atherogenic lipoproteins, mainly serum LDL-cholesterol (LDL-C), to very low levels can safely reduce overall atherosclerotic plaque burden and favourably modify plaque composition. Classically, this outcome has been achieved with intensive statin therapy. Since 2016, newer and potent lipid-lowering strategies, such as proprotein convertase subtilisin-kexin type 9 inhibition, have shown incremental effects on plaque regression and risk of clinical events. Despite maximal reduction in plasma LDL-C levels, considerable residual cardiovascular risk remains in some patients. Therefore, there is a need to study therapeutic approaches that address residual risk beyond LDL-C reduction to promote plaque stabilization or regression. Contemporary imaging modalities, such as coronary computed tomography angiography, enable non-invasive assessment of the overall atherosclerotic plaque burden as well as of certain local plaque characteristics. This technology could allow further study of plaque stabilization and regression using novel therapeutic approaches. Non-invasive plaque assessment might also offer the potential to guide personalized management strategies if validated for this purpose.

Thin-cap fibroatheroma in acute coronary syndrome: Implication for intravascular imaging assessment

Acute coronary syndrome (ACS), a significant cardiovascular disease threat, has garnered increased focus concerning its etiological mechanisms. Thin-cap fibroatheroma (TCFA) are central to ACS pathogenesis, characterized by lipid-rich plaques, profuse foam cells, cholesterol crystals, and fragile fibrous caps predisposed to rupture. While TCFAs may be latent and asymptomatic, their pivotal role in ACS risk is undeniable. High-resolution imaging techniques like Optical coherence tomography (OCT) and Intravascular ultrasound (IVUS) are instrumental for effective TCFA detection. Therapeutic strategies encompass pharmacological and interventional measures, including antiplatelet agents, statins, and Percutaneous Coronary Intervention (PCI), aiding in plaque stabilization, inflammation reduction, and rupture risk mitigation. Despite the strong correlation between TCFAs and adverse prognoses in ACS patients, early detection and rigorous treatment significantly enhance patient prognosis and diminish cardiovascular events. This review aims to encapsulate recent advancements in TCFA research within ACS, covering formation mechanisms, clinical manifestations, and prognostic implications.

Association of in situ thrombus within the patent foramen ovale and patients with migraine: A prospective cohort study

Background

Patent foramen ovale (PFO) is associated with migraine; however, the mechanism of PFO-associated migraine is not well known; additionally, percutaneous closure is controversial. This study aimed to investigate in situ thrombi within the PFO and explore the possible predictors of the effectiveness of PFO closure in migraineurs.

Methods

This prospective cohort study included 48 asymptomatic patients and 92 migraineurs with PFO. Optical coherence tomography (OCT) was used to evaluate the PFO microstructure. Only migraineurs underwent percutaneous closure. Migraineurs were divided into two cohorts based on the presence of a thrombus within the PFO. The symptoms were assessed at the 12-month follow-up visit. Predictors were evaluated employing multivariate logistic regression and receiver operating characteristic curve analyses.

Results

In situ thrombi within PFO were identified in 69 migraineurs and in two asymptomatic patients (76.7 % vs. 4.3 %; P < 0.001). Additionally, endocardial irregularity, discontinuity, low signal, and spasm were found in 59 (65.6 %), 15 (16.7 %), 13 (14.4 %), and six (6.7 %) patients, respectively, in the migraine group. In situ thrombus was associated with migraine risk (OR 49.03; 95%CI 8.52-282.18; P < 0.001). At the 12-month follow-up of the migraineur cohort, the primary endpoint, a 50 % reduction in migraine frequency after closure (with or without thrombus in PFO) was met (85.3 % vs. 25.0 %; P < 0.001). In situ thrombus was associated with migraine relief (OR 6.75; 95%CI 1.28-35.56; P = 0.024).

Conclusions

In situ thrombus and abnormal endocardium within PFOs were common in migraineurs, and in situ thrombus was a risk factor for migraine. Percutaneous closure was more effective in migraineurs with thrombi within the PFO. OCT imaging improved the understanding of pathogenic PFOs and may be helpful in selecting suitable migraineurs for PFO closure.

Vulnerable plaque features and adverse events in patients with diabetes mellitus: a post hoc analysis of the COMBINE OCT-FFR trial

BACKGROUND

Thin-cap fibroatheroma (TCFA) lesions are associated with a high risk of future major adverse cardiovascular events. However, the impact of other optical coherence tomography-detected vulnerability features (OCT-VFs) and their interplay with TCFA in predicting adverse events remains unknown.

AIMS

We aimed to evaluate the individual as well as the combined prognostic impact of OCT-VFs in predicting the incidence of the lesion-oriented composite endpoint (LOCE) in non-ischaemic lesions in patients with diabetes mellitus (DM).

METHODS

COMBINE OCT-FFR (ClinicalTrials.gov: NCT02989740) was a prospective, double-blind, international, natural history study that included DM patients with ≥1 non-culprit lesions with a fractional flow reserve>0.80 undergoing systematic OCT assessment. OCT-VFs included the following: TCFA, reduced minimal lumen area (r-MLA), healed plaque (HP), and complicated plaque (CP). The primary endpoint, LOCE - a composite of cardiac mortality, target vessel myocardial infarction, or clinically driven target lesion revascularisation up to 5 years - was analysed according to the presence of these OCT-VFs, both individually and in combination.

RESULTS

TCFA, r-MLA, HP and CP were identified in 98 (25.3%), 190 (49.0%), 87 (22.4%), and 116 (29.9%) patients, respectively. The primary endpoint rate increased progressively from 6.3% to 55.6% (hazard ratio 15.2, 95% confidence interval: 4.53-51.0; p<0.001) in patients without OCT-VFs as compared to patients with concomitant HP, r-MLA, CP, and TCFA. The coexistence of TCFA with other OCT-VFs resulted in an increased risk of the LOCE at 5 years.

CONCLUSIONS

In DM patients with non-ischaemic lesions, TCFA was the strongest predictor of future LOCE events. However, lesions that present additional OCT-VFs are associated with a higher risk of adverse events than OCT-detected TCFA alone. Further randomised studies are warranted to confirm these findings and their potential clinical implications.

Management of Coronary Vulnerable Plaque With Medical Therapy or Local Preventive Percutaneous Coronary Intervention

Acute coronary syndromes (ACS) often result from the rupture or erosion of high-risk coronary atherosclerotic plaques (ie, vulnerable plaques). Advances in intracoronary imaging such as intravascular ultrasound, optical coherence tomography, or near-infrared spectroscopy have improved the identification of vulnerable plaques, characterized by large plaque burden, small minimal luminal area, thin fibrous cap, and large lipid content. Although pharmacology, including lipid-lowering agents, and intensive risk-factor control are pivotal for management of vulnerable plaques and secondary prevention, recurrent events tend to accrue despite intensive pharmacotherapy. Therefore, it has been hypothesized that local preventive percutaneous coronary intervention may passivate these vulnerable plaques, preventing the occurrence of plaque-related ACS. However, solid evidence is lacking on its use for treatment of non-flow-limiting vulnerable plaques. As such, the optimal management of vulnerable plaques has not been established. Herein, we have reviewed the diagnosis and management of vulnerable plaques, focusing on systematic pharmacology and focal treatments.

Left anterior descending coronary artery-left circumflex coronary artery bifurcation angle and severity of coronary artery disease; is there any correlation? A cross-sectional study

Background and Aims

The aim of this study is to evaluate the association of coronary computed tomography angiography derived (CCTA) plaque characteristics and the left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) bifurcation angle with severity of coronary artery disease (CAD).

Methods

All the stable patients with suspected CAD who underwent CCTA between January to December 2021 were included. Correlation between CCTA-derived aggregated plaque volume (APV), LAD-LCX angle, remodeling index (RI), coronary calcium score with Gensini score in conventional angiography were assessed. One hundred and twenty-two patients who underwent both CCTA and coronary angiography were analyzed.

Results

Our analysis showed that the median (percentile 25% to percentile 75%) of the APV, LAD-LCx angle, and calcium score were 31% (17%-47%), 58° (39°-89°), and 31 (0-186), respectively. Also, the mean ± SD of the RI was 1.05 ± 0.20. Significant correlation between LAD-LCx bifurcation angle (0.0001-0.684), APV (0.002-0.281), RI (0.0001-0.438), and calcium score (0.016-0.217) with Gensini score were detected. There was a linear correlation between the mean LAD-LCx bifurcation angle and the Gensini score. The sensitivity and specificity for the cut-off value of 47.5° for the LAD-LCX angle were 86.7% and 82.1%, respectively.

Conclusion

There is a direct correlation between the LAD-LCx angle and the Gensini score. In addition to plaque characteristics, anatomic-based CCTA-derived indices can be used to identify patients at higher risk for CAD.

Coronary calcified nodules versus nonnodular coronary calcifications: a systematic review and meta-analysis

BACKGROUND

Percutaneous coronary intervention (PCI) on severely calcified coronary lesions is challenging. Coronary calcified nodule (CN) refers to an eccentric and protruding coronary calcification associated with plaque vulnerability and adverse clinical events. This study aims to conduct an extensive review of CNs, focusing on its prognostic impact in comparison with nonnodular coronary calcification (N-CN).

METHOD

A systematic literature review on PubMed, MEDLINE, and EMBASE databases was conducted for relevant articles. Observational studies or randomized controlled trials comparing CNs and N-CNs were included.

RESULTS

Five studies comparing CNs and N-CNs were pertinent for inclusion. The total number of individuals across these studies was 1456. There were no significant differences in the baseline demographic, clinical, and angiographic data between the CN and N-CN groups. Intracoronary imaging was always utilized. At follow-up, CNs were associated with significantly increased, target vessel revascularization [odds ratio (OR) 2.16; 95% confidence interval (CI): 1.39-3.36, P-value < 0.01, I2 = 0%] and stent thrombosis (OR 9.29; 95% CI: 1.67-51.79, P-value = 0.01, I2 = 0%) compared with N-CN. A trend for greater cardiac death was also assessed in the CN group (OR 1.75; 95% CI: 0.98-3.13, P-value = 0.06, I2 = 0%).

CONCLUSION

CN has a significantly negative impact on outcomes when compared with N-CN.

Invasive electrochemical impedance spectroscopy with phase delay for experimental atherosclerosis phenotyping

Distinguishing quiescent from rupture-prone atherosclerotic lesions has significant translational and clinical implications. Electrochemical impedance spectroscopy (EIS) characterizes biological tissues by assessing impedance and phase delay responses to alternating current at multiple frequencies. We evaluated invasive 6-point stretchable EIS sensors over a spectrum of experimental atherosclerosis and compared results with intravascular ultrasound (IVUS), molecular positron emission tomography (PET) imaging, and histology. Male New Zealand White rabbits (n = 16) were placed on a high-fat diet, with or without endothelial denudation via balloon injury of the infrarenal abdominal aorta. Rabbits underwent in vivo micro-PET imaging of the abdominal aorta with 68Ga-DOTATATE, 18F-NaF, and 18F-FDG, followed by invasive interrogation via IVUS and EIS. Background signal-corrected values of impedance and phase delay were determined. Abdominal aortic samples were collected for histology. Analyses were performed blindly. EIS impedance was associated with markers of plaque activity including macrophage infiltration (r = .813, p = .008) and macrophage/smooth muscle cell (SMC) ratio (r = .813, p = .026). Moreover, EIS phase delay correlated with anatomic markers of plaque burden, namely intima/media ratio (r = .883, p = .004) and %stenosis (r = .901, p = .002), similar to IVUS. 68Ga-DOTATATE correlated with intimal macrophage infiltration (r = .861, p = .003) and macrophage/SMC ratio (r = .831, p = .021), 18F-NaF with SMC infiltration (r = -.842, p = .018), and 18F-FDG correlated with macrophage/SMC ratio (r = .787, p = .036). EIS with phase delay integrates key atherosclerosis features that otherwise require multiple complementary invasive and non-invasive imaging approaches to capture. These findings indicate the potential of invasive EIS to comprehensively evaluate human coronary artery disease.

Discovering Inflammation in Atherosclerosis: Insights from Pathogenic Pathways to Clinical Practice

This comprehensive review explores the various scenarios of atherosclerosis, a systemic and chronic arterial disease that underlies most cardiovascular disorders. Starting from an overview of its insidious development, often asymptomatic until it reaches advanced stages, the review delves into the pathophysiological evolution of atherosclerotic lesions, highlighting the central role of inflammation. Insights into clinical manifestations, including heart attacks and strokes, highlight the disease's significant burden on global health. Emphasis is placed on carotid atherosclerosis, clarifying its epidemiology, clinical implications, and association with cognitive decline. Prevention strategies, lifestyle modifications, risk factor management, and nuanced antithrombotic treatment considerations are critical to managing cardiovascular complications, thus addressing a crucial aspect of cardiovascular health.

Inflammation in HIV and Its Impact on Atherosclerotic Cardiovascular Disease

People living with HIV have a 1.5- to 2-fold increased risk of developing cardiovascular disease. Despite treatment with highly effective antiretroviral therapy, people living with HIV have chronic inflammation that makes them susceptible to multiple comorbidities. Several factors, including the HIV reservoir, coinfections, clonal hematopoiesis of indeterminate potential (CHIP), microbial translocation, and antiretroviral therapy, may contribute to the chronic state of inflammation. Within the innate immune system, macrophages harbor latent HIV and are among the prominent immune cells present in atheroma during the progression of atherosclerosis. They secrete inflammatory cytokines such as IL (interleukin)-6 and tumor necrosis-α that stimulate the expression of adhesion molecules on the endothelium. This leads to the recruitment of other immune cells, including cluster of differentiation (CD)8+ and CD4+ T cells, also present in early and late atheroma. As such, cells of the innate and adaptive immune systems contribute to both systemic inflammation and vascular inflammation. On a molecular level, HIV-1 primes the NLRP3 (NLR family pyrin domain containing 3) inflammasome, leading to an increased expression of IL-1β, which is important for cardiovascular outcomes. Moreover, activation of TLRs (toll-like receptors) by HIV, gut microbes, and substance abuse further activates the NLRP3 inflammasome pathway. Finally, HIV proteins such as Nef (negative regulatory factor) can inhibit cholesterol efflux in monocytes and macrophages through direct action on the cholesterol transporter ABCA1 (ATP-binding cassette transporter A1), which promotes the formation of foam cells and the progression of atherosclerotic plaque. Here, we summarize the stages of atherosclerosis in the context of HIV, highlighting the effects of HIV, coinfections, and antiretroviral therapy on cells of the innate and adaptive immune system and describe current and future interventions to reduce residual inflammation and improve cardiovascular outcomes among people living with HIV.

Comparison of interventional treatment options for coronary calcified nodules: A sub-analysis of the ROTA.shock trial

BACKGROUND

The optimal treatment for coronary calcified nodules (CNs) is still unclear. The aim of this study was to compare the modification of these lesions by coronary intravascular lithotripsy (IVL) and rotational atherectomy (RA) using optical coherence tomography (OCT).

METHODS

ROTA.shock was a 1:1 randomized, prospective, double-arm multi-center non-inferiority trial that compared the use of IVL and RA with percutaneous coronary intervention (PCI) in severely calcified lesions. In 19 of the patients out of this study CNs were detected by OCT in the target lesion and were treated by either IVL or RA.

RESULTS

The mean angle of CNs was significantly larger in final OCT scans than before RA (92 ± 17° vs. 68 ± 7°; p = 0.01) and IVL (89 ± 18° vs. 60 ± 10°; p = 0.03). The CNs were thinner upon final scans than in initial native scans (RA: 17.8 ± 7.8 mm vs. 38.6 ± 13.1 mm; p = 0.02; IVL: 16.5 ± 9.0 mm vs. 37.2 ± 14.3 mm; p = 0.02). Nodule volume did not differ significantly between native and final OCT scans (RA: 0.66 ± 0.12 mm3 vs. 0.61 ± 0.33 mm3; p = 0.68; IVL: 0.64 ± 0.19 mm3 vs. 0.68 ± 0.22 mm3; p = 0.74). Final stent eccentricity was high with 0.62 ± 0.10 after RA and 0.61 ± 0.09 after IVL.

CONCLUSION

RA or IVL are unable to reduce the volume of the calcified plaque. CN modulation seems to be mainly induced by the stent implantation and not by RA or IVL.

The Antioxidant Dendrobium officinale Polysaccharide Modulates Host Metabolism and Gut Microbiota to Alleviate High-Fat Diet-Induced Atherosclerosis in ApoE-/- Mice

BACKGROUND

The discovery of traditional plants' medicinal and nutritional properties has opened up new avenues for developing pharmaceutical and dietary strategies to prevent atherosclerosis. However, the effect of the antioxidant Dendrobium officinale polysaccharide (DOP) on atherosclerosis is still not elucidated.

PURPOSE

This study aims to investigate the inhibitory effect and the potential mechanism of DOP on high-fat diet-induced atherosclerosis in Apolipoprotein E knockout (ApoE-/-) mice.

STUDY DESIGN AND METHODS

The identification of DOP was measured by high-performance gel permeation chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR). We used high-fat diet (HFD)-induced atherosclerosis in ApoE-/- mice as an animal model. In the DOP intervention stage, the DOP group was treated by gavage with 200 μL of 200 mg/kg DOP at regular times each day and continued for eight weeks. We detected changes in serum lipid profiles, inflammatory factors, anti-inflammatory factors, and antioxidant capacity to investigate the effect of the DOP on host metabolism. We also determined microbial composition using 16S rRNA gene sequencing to investigate whether the DOP could improve the structure of the gut microbiota in atherosclerotic mice.

RESULTS

DOP effectively inhibited histopathological deterioration in atherosclerotic mice and significantly reduced serum lipid levels, inflammatory factors, and malondialdehyde (F/B) production. Additionally, the levels of anti-inflammatory factors and the activity of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), were significantly increased after DOP intervention. Furthermore, we found that DOP restructures the gut microbiota composition by decreasing the Firmicutes/Bacteroidota (F/B) ratio. The Spearman's correlation analysis indicated that serum lipid profiles, antioxidant activity, and pro-/anti-inflammatory factors were associated with Firmicutes, Bacteroidota, Allobaculum, and Coriobacteriaceae_UCG-002.

CONCLUSIONS

This study suggests that DOP has the potential to be developed as a food prebiotic for the treatment of atherosclerosis in the future.

Drug-Coated Balloon in Acute Coronary Syndromes: Ready for the Prime Time?

PURPOSE OF REVIEW

Acute coronary syndromes (ACS) are a major global health concern. Percutaneous coronary intervention (PCI) with new-generation drug-eluting stents (DES) has been endorsed as safe and effective in the management of culprit and non-culprit lesions of ACS. However, permanent metallic implants may have drawbacks, including the need for prolonged dual antiplatelet therapy (DAPT) and the risk of long-term stent-related complications. An alternative approach using drug-coated balloons (DCBs) is gaining growing interest, having the potential of delivering therapy directly to vulnerable plaques, avoiding the need for permanent metallic implants, and potentially allowing for better long-term medical treatment. Despite limited evidence, DCB is being explored in several patients' subgroups. This review aims to discuss the existing evidence regarding DCB in ACS management.

RECENT FINDINGS

DCB appears to be a promising strategy in the management of ACS, showing comparable angiographic and clinical results as compared to new-generation DES in relatively small clinical trials or large prospective registries. The advantage of avoiding permanent implants is particularly appealing in this setting, where DCB has the potential of delivering anti-atherogenic local therapy directly to vulnerable plaques still amenable to atherogenic regression. This review seeks to underline the theoretical background of DCB use and reports the available evidence in its support in the specific setting of ACS. In the context of ACS, the use of DCB is highly attractive, offering a dedicated anti-atherogenic local therapy, capable of addressing a broad range of vulnerable plaques and patients.

A novel rabbit model of atherosclerotic vulnerable plaque established by cryofluid-induced endothelial injury

Acute thrombosis secondary to atherosclerotic plaque rupture is the main cause of acute cardiac and cerebral ischemia. An animal model of unstable atherosclerotic plaques is highly important for investigating the mechanism of plaque rupture and thrombosis. However, current animal models involve complex operations, are costly, and have plaque morphologies that are different from those of humans. We aimed to establish a simple animal model of vulnerable plaques similar to those of humans. Rabbits were randomly divided into three groups. Group A was given a normal formula diet for 13 weeks. Group C underwent surgery on the intima of the right carotid artery with - 80 °C cryofluid-induced injury after 1 week of a high-fat diet and further feeding a 12-week high-fat diet. Group B underwent the same procedure as Group C but without the - 80 °C cryofluid. Serum lipid levels were detected via ELISA. The plaque morphology, stability and degree of stenosis were evaluated through hematoxylin-eosin (HE) staining, Masson trichrome staining, Elastica van Gieson staining (EVG), and oil red O staining. Macrophages and inflammatory factors in the plaques were assessed via immunohistochemical analysis. The serum low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), and total cholesterol (TC) levels in groups B and C were significantly greater than those in group A. No plaque formation was observed in group A. The plaques in group B were very small. In group C, obvious plaques were observed in the blood vessels, and the plaques exhibited a thin fibrous cap, a large lipid core, and partially visible neovascularization, which is consistent with the characteristics of vulnerable plaques. In the plaques of group C, a large number of macrophages were present, and matrix metalloproteinase 9 (MMP-9) and lectin-like oxidized LDL receptor 1 (LOX-1) were abundantly expressed. We successfully established a rabbit model of vulnerable carotid plaque similar to that of humans through the combination of cryofluid-induced endothelial injury and a high-fat diet, which is feasible and cost effective.

Spectral Photon-Counting Computed Tomography: Technical Principles and Applications in the Assessment of Cardiovascular Diseases

Spectral Photon-Counting Computed Tomography (SPCCT) represents a groundbreaking advancement in X-ray imaging technology. The core innovation of SPCCT lies in its photon-counting detectors, which can count the exact number of incoming x-ray photons and individually measure their energy. The first part of this review summarizes the key elements of SPCCT technology, such as energy binning, energy weighting, and material decomposition. Its energy-discriminating ability represents the key to the increase in the contrast between different tissues, the elimination of the electronic noise, and the correction of beam-hardening artifacts. Material decomposition provides valuable insights into specific elements' composition, concentration, and distribution. The capability of SPCCT to operate in three or more energy regimes allows for the differentiation of several contrast agents, facilitating quantitative assessments of elements with specific energy thresholds within the diagnostic energy range. The second part of this review provides a brief overview of the applications of SPCCT in the assessment of various cardiovascular disease processes. SPCCT can support the study of myocardial blood perfusion and enable enhanced tissue characterization and the identification of contrast agents, in a manner that was previously unattainable.

CircHIPK3 targets DRP1 to mediate hydrogen peroxide-induced necroptosis of vascular smooth muscle cells and atherosclerotic vulnerable plaque formation

INTRODUCTION

Necroptosis triggered by H2O2 is hypothesized to be a critical factor in the rupture of atherosclerotic plaques, which may precipitate acute cardiovascular events. Nevertheless, the specific regulatory molecules of this development remain unclear. We aims to elucidate a mechanism from the perspective of circular RNA.

OBJECTIVES

There are few studies on circRNA in VSMCs necroptosis. The objective of our research is to shed light on the intricate roles that circHIPK3 plays in the process of necroptosis in VSMCs and the development of atherosclerotic plaques that are prone to rupture. Our study elucidates the specific molecular mechanisms by which circHIPK3 regulates necroptosis and atherosclerotic vulnerable plaque formation through targeted proteins. Identifying this mechanism at the cellular level offers a molecular framework for understanding plaque progression and stability regulation, as well as a potential biomarker for the prognosis of susceptible atherosclerotic plaques.

METHODS

We collected clinical vascular tissue for HE staining and Masson staining to determine the presence and stability of plaques. Then, NCBI database was used to screen out circRNA with elevated expression level in plaque tissue, and the up-regulated circRNA, circHIPK3, was verified by qRT-PCR and FISH. Further, we synthesized circHIPK3's small interference sequence and overexpressed plasmid in vitro, and verified its regulation effect on necroptosis of VSMCs under physiological and pathological conditions by WB, qRT-PCR and PI staining. Through RNA pull down, mass spectrometry and RNA immunoprecipitation, DRP1 was identified as circHIPK3 binding protein and was positively regulated by circHIPK3. Meanwhile, on the basis of silencing of DRP1, the regulation of circHIPK3 on necroptosis is verified to be mediated by DRP1. Finally, we validated the regulation of circHIPK3 on vulnerable plaque formation in ApoE-/- mice.

RESULTS

We investigated that circHIPK3 was highly expressed in vulnerable plaques, and the increase in expression level promoted H2O2 induced necroptosis of VSMCs. CircHIPK3 targeted the protein DRP1, leading to an elevation in mitochondrial division rate, resulting in increased reactive oxygen species and impaired mitochondrial function, ultimately leading to necroptosis of VSMCs and vulnerable plaque formation.

CONCLUSION

CircHIPK3 interact with DRP1 involve in H2O2 induced Mitochondrial damage and necroptosis of VSMCs, and Silencing circHIPK3 in vivo can reduce atherosclerotic vulnerable plaque formation. Our research findings may have applications in providing diagnostic biomarkers for vulnerable plaques.

Validity of Atherosclerotic Calcified Lesions Observed on Low-Dose Computed Tomography and Cardio-Ankle Vascular Index as Surrogate Markers of Atherosclerosis Progression

The significance of atherosclerotic calcified lesions observed on low-dose computed tomography (LDCT) performed during general checkups was investigated. The coronary arteries (CA), ascending aorta and aortic arch (AAAA), descending thoracic aorta (DTA), and abdominal aorta (AA) were examined. Semiquantitative calcified index analysis of the DTA and AA in terms of atherosclerosis risk factors and cardio-ankle vascular index (CAVI) measurements was also performed. We included 1594 participants (mean age: 59.2 years; range: 31-91 years). The prevalence of calcified lesions was 71.0%, 66.6%, 57.2%, and 37.9% in the AA, CA, AAAA, and DTA, respectively. Age-related advances in calcification among participants with no major risk factors, revealed that calcification appeared earliest in the AA, followed by the CA, AAAA, and DTA. Participants with calcified lesions in all arteries had a significantly greater CAVI than those without calcification. The CAVI was negatively correlated with low-density lipoprotein cholesterol levels, particularly in participants without calcified lesions in the DTA. Calcified lesions on LDCT could indicate the end stage of atherosclerotic lesions. The CAVI can be used to assess atherosclerotic changes at all stages of disease progression. A combination of LDCT and CAVI could be used as a routine non-invasive assessment of atherosclerosis.

The interplay of collagen, macrophages, and microcalcification in atherosclerotic plaque cap rupture mechanics

The rupture of an atherosclerotic plaque cap overlying a lipid pool and/or necrotic core can lead to thrombotic cardiovascular events. In essence, the rupture of the plaque cap is a mechanical event, which occurs when the local stress exceeds the local tissue strength. However, due to inter- and intra-cap heterogeneity, the resulting ultimate cap strength varies, causing proper assessment of the plaque at risk of rupture to be lacking. Important players involved in tissue strength include the load-bearing collagenous matrix, macrophages, as major promoters of extracellular matrix degradation, and microcalcifications, deposits that can exacerbate local stress, increasing tissue propensity for rupture. This review summarizes the role of these components individually in tissue mechanics, along with the interplay between them. We argue that to be able to improve risk assessment, a better understanding of the effect of these individual components, as well as their reciprocal relationships on cap mechanics, is required. Finally, we discuss potential future steps, including a holistic multidisciplinary approach, multifactorial 3D in vitro model systems, and advancements in imaging techniques. The obtained knowledge will ultimately serve as input to help diagnose, prevent, and treat atherosclerotic cap rupture.

Dual modality intravascular catheter system combining pulse-sampling fluorescence lifetime imaging and polarization-sensitive optical coherence tomography

The clinical management of coronary artery disease and the prevention of acute coronary syndromes require knowledge of the underlying atherosclerotic plaque pathobiology. Hybrid imaging modalities capable of comprehensive assessment of biochemical and morphological plaques features can address this need. Here we report the first implementation of an intravascular catheter system combining fluorescence lifetime imaging (FLIm) with polarization-sensitive optical coherence tomography (PSOCT). This system provides multi-scale assessment of plaque structure and composition via high spatial resolution morphology from OCT, polarimetry-derived tissue microstructure, and biochemical composition from FLIm, without requiring any molecular contrast agent. This result was achieved with a low profile (2.7 Fr) double-clad fiber (DCF) catheter and high speed (100 fps B-scan rate, 40 mm/s pullback speed) console. Use of a DCF and broadband rotary junction required extensive optimization to mitigate the reduction in OCT performance originating from additional reflections and multipath artifacts. This challenge was addressed by the development of a broad-band (UV-visible-IR), high return loss (47 dB) rotary junction. We demonstrate in phantoms, ex vivo swine coronary specimens and in vivo swine heart (percutaneous coronary access) that the FLIm-PSOCT catheter system can simultaneously acquire co-registered FLIm data over four distinct spectral bands (380/20 nm, 400/20 nm, 452/45 nm, 540/45 nm) and PSOCT backscattered intensity, birefringence, and depolarization. The unique ability to collect complementary information from tissue (e.g., morphology, extracellular matrix composition, inflammation) with a device suitable for percutaneous coronary intervention offers new opportunities for cardiovascular research and clinical diagnosis.

Cardiovascular multimodality imaging in women: a scientific statement of the European Association of Cardiovascular Imaging of the European Society of Cardiology

Cardiovascular diseases (CVD) represent an important cause of mortality and morbidity in women. It is now recognized that there are sex differences regarding the prevalence and the clinical significance of the traditional cardiovascular (CV) risk factors as well as the pathology underlying a range of CVDs. Unfortunately, women have been under-represented in most CVD imaging studies and trials regarding diagnosis, prognosis, and therapeutics. There is therefore a clear need for further investigation of how CVD affects women along their life span. Multimodality CV imaging plays a key role in the diagnosis of CVD in women as well as in prognosis, decision-making, and monitoring of therapeutics and interventions. However, multimodality imaging in women requires specific consideration given the differences in CVD between the sexes. These differences relate to physiological changes that only women experience (e.g. pregnancy and menopause) as well as variation in the underlying pathophysiology of CVD and also differences in the prevalence of certain conditions such as connective tissue disorders, Takotsubo, and spontaneous coronary artery dissection, which are all more common in women. This scientific statement on CV multimodality in women, an initiative of the European Association of Cardiovascular Imaging of the European Society of Cardiology, reviews the role of multimodality CV imaging in the diagnosis, management, and risk stratification of CVD, as well as highlights important gaps in our knowledge that require further investigation.

The dance of macrophage death: the interplay between the inevitable and the microenvironment

Macrophages are highly plastic cells ubiquitous in various tissues, where they perform diverse functions. They participate in the response to pathogen invasion and inflammation resolution following the immune response, as well as the maintenance of homeostasis and proper tissue functions. Macrophages are generally considered long-lived cells with relatively strong resistance to numerous cytotoxic factors. On the other hand, their death seems to be one of the principal mechanisms by which macrophages perform their physiological functions or can contribute to the development of certain diseases. In this review, we scrutinize three distinct pro-inflammatory programmed cell death pathways - pyroptosis, necroptosis, and ferroptosis - occurring in macrophages under specific circumstances, and explain how these cells appear to undergo dynamic yet not always final changes before ultimately dying. We achieve that by examining the interconnectivity of these cell death types, which in macrophages seem to create a coordinated and flexible system responding to the microenvironment. Finally, we discuss the complexity and consequences of pyroptotic, necroptotic, and ferroptotic pathway induction in macrophages under two pathological conditions - atherosclerosis and cancer. We summarize damage-associated molecular patterns (DAMPs) along with other microenvironmental factors, macrophage polarization states, associated mechanisms as well as general outcomes, as such a comprehensive look at these correlations may point out the proper methodologies and potential therapeutic approaches.

Application of Dual-Layer Spectral-Detector Computed Tomography Angiography in Identifying Symptomatic Carotid Atherosclerosis: A Prospective Observational Study

BACKGROUND

Dual-layer spectral-detector dual-energy computed tomography angiography (DLCTA) can distinguish components of carotid plaques. Data on identifying symptomatic carotid plaques in patients using DLCTA are not available.

METHODS AND RESULTS

In this prospective observational study, patients with carotid plaques were enrolled and received DLCTA. The attenuation for both polyenergetic image and virtual monoenergetic images (40, 70, 100, and 140 keV), as well as Z-effective value, were recorded in the noncalcified regions of plaques. Logistic regression models were used to assess the association between attenuations of DLCTA and the presence of symptomatic carotid plaques. In total, 100 participants (mean±SD age, 64.37±8.31 years; 82.0% were men) were included, and 36% of the cases were identified with the symptomatic group. DLCTA parameters were different between 2 groups (symptomatic versus asymptomatic: computed tomography [CT] 40 keV, 152.63 [interquartile range (IQR), 70.22-259.78] versus 256.78 [IQR, 150.34-408.13]; CT 70 keV, 81.28 [IQR, 50.13-119.33] versus 108.87 [IQR, 77.01-165.88]; slope40-140 keV, 0.91 [IQR, 0.35-1.87] versus 1.92 [IQR, 0.96-3.00]; Z-effective value, 7.92 [IQR, 7.53-8.46] versus 8.41 [IQR, 7.94-8.92]), whereas no difference was found in conventional polyenergetic images. The risk of symptomatic plaque was lower in the highest tertiles of attenuations in CT 40 keV (adjusted odds ratio [OR], 0.243 [95% CI, 0.078-0.754]), CT 70 keV (adjusted OR, 0.313 [95% CI, 0.104-0.940]), Z-effective values (adjusted OR, 0.138 [95% CI, 0.039-0.490]), and slope40-140 keV (adjusted OR, 0.157 [95% CI, 0.046-0.539]), with all P values and P trends <0.05. The areas under the curve for CT 40 keV, CT 70 keV, slope 40 to 140 keV, and Z-effective values were 0.64, 0.61, 0.64, and 0.63, respectively.

CONCLUSIONS

Parameters of DLCTA might help assist in distinguishing symptomatic carotid plaques. Further studies with a larger sample size may address the overlap and improve the diagnostic accuracy.