From vulnerable plaque to vulnerable patient: a call for new definitions and risk assessment strategies: Part I

Association Between the Amount of Carotid Perivascular Adipose Tissue and Prior Ischemic Stroke: An MR Imaging Study

BACKGROUND

This study aimed to explore the association between the amount of carotid artery perivascular adipose tissue (PVAT) quantified by magnetic resonance imaging and prior cerebral infarction.

METHODS

A total of 139 patients (mean age, 64.4±8.2 years; 112 men) with moderate-to-severe atherosclerotic stenosis referred to carotid endarterectomy were included and underwent multicontrast magnetic resonance vessel wall and brain imaging. The amount of carotid artery PVAT with vulnerable plaque components on magnetic resonance images of each patient was quantitatively analyzed, and the measurements included the average PVAT area, PVAT area index, and PVAT volume index. The amount measurements of PVAT at slices with vulnerable plaque between patients with and without prior cerebral infarction were compared. Logistic regression analyses were conducted to determine the association between the amount measurements of PVAT and prior cerebral infarction.

RESULTS

Patients with prior cerebral infarction showed significantly higher PVAT area, PVAT area index, and PVAT volume index compared with those without (all P<0.01). The carotid PVAT area (odds ratio [OR], 1.015 [95% CI, 1.003-1.028]; P=0.018), PVAT area index (OR, 2.051 [95% CI, 1.084-3.880]; P=0.027), and PVAT volume index (OR, 2.864 [95% CI, 1.343-6.108]; P=0.006) on the index side were significantly associated with prior cerebral infarction in univariate logistic regression. After adjusting for clinical confounding factors and plaque features, the associations between carotid PVAT area (OR, 1.028 [95% CI, 1.008-1.048]; P=0.006), PVAT area index (OR, 3.587 [95% CI, 1.451-8.870]; P=0.006), and PVAT volume index (OR, 6.053 [95% CI, 2.048-17.889]; P=0.001) and prior cerebral infarction remained statistically significant.

CONCLUSIONS

The amount of PVAT in carotid artery with vulnerable plaques is independently associated with prior cerebral infarction and may, therefore, be related to the occurrence of ischemic stroke.

Incidence of ocular ischemic syndrome in patients with asymptomatic severe internal carotid artery stenosis

OBJECTIVES

To evaluate the incidence of ocular ischemic syndrome (OIS) in patients with asymptomatic Severe Internal Carotid Artery Stenosis or occluded (ipICA-SO).

DESIGN AND METHODS

260 patients with ipICA stenosis ≥ 70%, 120 patients with ipsilateral OIS, and 140 with normal ocular condition. The logistic regression analysis was conducted to establish risk prediction models of OIS/Neovascular-OIS/Chronic-OIS for patients with ipICA-SO. The area under the receiver operating characteristic curve (AUC) was used to test the application value of the prediction models.

RESULTS

In ipICA-SO patients, OIS patients showed significantly higher incidence of ipICA occlusion (p < 0.001), plaque unstable (p < 0.001 ipsilateral/contralateral) or plaque located at both the primary and siphon section (p = 0.004 in ipsilateral), contralateral ICA or anterior/middle cerebral artery severe stenosis (p = 0.001, 0.016, 0.040, respectively), and ipsilateral OphAr low /reflux blood flow (p < 0.001). The hypertension was significantly higher in the control group (p = 0.002). The AUC of the prediction model of OIS was 0.834. Diabetes mellitus (DM) and OphAr reflux blood flow are risk factors for Neovascular-OIS. The AUC of Neovascular-OIS was 0.724. Chronic progress is likely in OIS patients with ipICA occlusion and DM. The AUC of Chronic-OIS was 0.673.

CONCLUSIONS

The ipICA-SO patients without sufficient collateral flow are more likely to develop OIS. IpICA-SO patients with hypertension had a lower risk of developing OIS. Neovascular was commonly found in OIS patients with DM and reversed OphAr blood flow. Chronic OIS was associated with ipICA total occlude and DM.

Chronic Alcohol Exposure Modulates Atherosclerotic Plaque Vulnerability in ApoE Knockout Mice

AIM

This study aimed to examine the effect of chronic alcohol consumption on the development and progression of atherosclerosis in apolipoprotein E-knockout (ApoE-/-) mice.

METHOD

Male ApoE-/- mice, aged 8 weeks, were randomly assigned to four groups: control, model, low-dose alcohol, and high-dose alcohol. The mice were fed a normal chow or high-fat diet for 14 weeks, with water provided alongside 1% (v/v) or 5% (v/v) alcohol solutions.

RESULTS

Mice in the 1% (v/v) alcohol group showed a significant increase in subcutaneous and epididymal fat compared to those in the model group. However, basal metabolic markers remained unchanged in the 5% (v/v) alcohol group, although water intake was significantly lower. Histological analyses of the experimental groups exposed to alcohol revealed no protective effects against atherosclerosis in the aortic tree or plaque deposition in the aortic root. Additionally, no significant changes were observed in the macrophages and smooth muscle cells within the aortic root plaques. Nevertheless, low-dose alcohol exposure protected plaque vulnerability compared with the model group, whereas high-dose alcohol had no effect. Transcriptomic analysis of aortic tissue further indicated that alcohol consumption reduced the expression of genes related to lipid transport and metabolic abnormalities.

Rapid identifying for high-risk Type B aortic dissection populations: A hemodynamic study

Currently, the blood force on the vessel wall (BFVW) is generally obtained using computational fluid dynamics (CFD), which is hampered by professional CFD knowledge to perform the correct simulation. This study aims to propose a new method to quickly calculate BFVW in TBAD-susceptible areas and to find the association between BFVW and the occurrence of TBAD. Using the momentum theorem, a fast, accurate, and clinician-friendly non-numerical simulation method was proposed and validated against CFD in 30 high-risk TBAD patients and 30 healthy controls. It is found out that aortic geometric morphology of one specific patient experienced almost no change before and after the onset of TBAD. The post-onset imaging data of acute TBAD patients is adequate as pre-onset models. The linear regression analysis showed good agreement in BFVW calculated by the two methods (R > 0.98). The magnitude of BFVW in the TBAD groups was significantly greater than in healthy controls (23.22 N ± 5.64 N vs 15.37 N ± 3.08 N, P < 0.01). The BFVW orientation in the healthy control group was primarily vertical, whereas the angle between the BFVW and the vertical direction was greater in the TBAD group (P < 0.01). The proposed method can quickly and accurately calculate patient-specific BFVW. It can therefore help clinicians identify potential TBAD populations early on and provide further evidence for optimizing blood pressure management to prevent TBAD.

Advances in the Application of Artificial Intelligence in the Ultrasound Diagnosis of Vulnerable Carotid Atherosclerotic Plaque

Vulnerable atherosclerotic plaque is a type of plaque that poses a significant risk of high mortality in patients with cardiovascular disease. Ultrasound has long been used for carotid atherosclerosis screening and plaque assessment due to its safety, low cost and non-invasive nature. However, conventional ultrasound techniques have limitations such as subjectivity, operator dependence, and low inter-observer agreement, leading to inconsistent and possibly inaccurate diagnoses. In recent years, a promising approach to address these limitations has emerged through the integration of artificial intelligence (AI) into ultrasound imaging. It was found that by training AI algorithms with large data sets of ultrasound images, the technology can learn to recognize specific characteristics and patterns associated with vulnerable plaques. This allows for a more objective and consistent assessment, leading to improved diagnostic accuracy. This article reviews the application of AI in the field of diagnostic ultrasound, with a particular focus on carotid vulnerable plaques, and discusses the limitations and prospects of AI-assisted ultrasound. This review also provides a deeper understanding of the role of AI in diagnostic ultrasound and promotes more research in the field.

Serum chemokines combined with multi-modal imaging to evaluate atherosclerotic plaque stability in patients undergoing carotid endarterectomy

Background

Although imaging tools are crucial in identifying features of atherosclerotic plaque, there remains a lack of consensus on the use of serological markers for assessing high-risk plaques.

Methods

Patients diagnosed with CAS who met the criteria for CEA were categorized as the operation group, while those without CAS were designated as the control group. Multi-modal imaging was conducted pre- and post-CEA to evaluate plaque features, such as the volume of calcification and LRNC, intra-plaque hemorrhage, and the degree of carotid stenosis. Serum chemokine levels were measured in both groups before CEA and on the 7th day post-surgery. Morphological features of carotid artery specimens were assessed using H&E and IHC (CD68 and α-SMA) staining to evaluate plaque stability.

Results

No significant differences in the degree of CAS between the operation and control groups. Among the operation group, 26 out of 52 patients were identified as vulnerable plaques. The volume of LRNC was significantly higher in vulnerable plaque, whereas the volume of calcification was significantly lower in vulnerable plaque compared to stable plaque confirmed by multi-modal imaging. Vulnerable plaque exhibited a thin fibrous cap covered an LRNC, intra-plaque hemorrhage, and macrophage infiltration. Stable plaque were characterized by small lipid cores covered by a thick fibrous cap, with minimal macrophage infiltration. Chemokine levels were significantly elevated in CAS patients compared to controls, and decreased significantly on the 7th day post-CEA. In patients with vulnerable plaque, lower levels of CX3CL1, CXCL12, CCL19, and CCL21, but higher levels of CCL2 and CCL5, were observed compared to patients with stable plaque. Correlation analysis further indicated that CX3CL1 and CXCL12 levels were positively associated with calcification volume. While CCL2 and CCL5 levels were positively associated, and CCL19 and CCL21 negatively associated, with LRNC volume. Multivariate analysis suggested that CXCL12 was an independent protective factor and LRNC volume as an independent risk factor for plaque vulnerability. The combination with multi-modal imaging and serological markers enhanced both the sensitivity (87.31%) and specificity (92.31%) in predicting plaque stability, with an AUC of 0.9001.

Conclusion

Combining multi-modal imaging with serological markers provides a more comprehensive evaluation of atherosclerotic plaque features.

Development of a nomogram model for predicting acute stroke events based on dual-energy CTA analysis of carotid intraplaque and perivascular adipose tissue

Objective

To evaluate the predictive value of dual-energy CT angiography (DECTA) parameters of carotid intraplaque and perivascular adipose tissue (PVAT) in acute stroke events.

Methods

A retrospective analysis was conducted using clinical, laboratory, and imaging data from patients who underwent dual-energy carotid CTA and cranial MRI. Acute cerebral infarctions occurring in the ipsilateral anterior circulation were classified as the symptomatic group (STA group), while other cases were categorized as the asymptomatic group (ATA group). LASSO regression was employed to identify key predictors. These predictors were used to develop three models: the intraplaque model (IP_Model), the perivascular adipose tissue model (PA_Model), and the nomogram model (Nomo_Model). The predictive accuracy of the models was evaluated using receiver operating characteristic (ROC) analysis, calibration curves, and decision curve analysis. Statistical significance was defined as p < 0.05.

Results

Seventy-five patients (mean age: 68.7 ± 8.7 years) were analyzed. LASSO regression identified seven significant variables (IP_Zeff, IP_40KH, IP_K, PA_FF, PA_VNC, PA_Rho, PA_K) for model construction. The Nomo_Model demonstrated superior predictive performance compared to the IP_Model and PA_Model, achieving an area under the curve (AUC) of 0.962, with a sensitivity of 95.8%, specificity of 82.4%, precision of 82.6%, an F1 score of 0.809, and an accuracy of 88.0%. The clinical decision curve analysis further validated the Nomo_Model's significant clinical utility.

Conclusion

DECTA imaging parameters revealed significant differences in carotid intraplaque and PVAT characteristics between the STA and ATA groups. Integrating these parameters into the nomogram (Nomo_Model) resulted in a highly accurate and clinically relevant tool for predicting acute stroke risk.

Enhanced intravascular lithotripsy (IVL) with ultrasound-shockwave catheter

Intravascular shockwave lithotripsy (IVL) is an effective treatment for vascular calcification. Previous studies suggest that ultrasound can enhance the efficiency of extracorporeal shockwave lithotripsy (ESWL) by mitigating the bubble shielding effect. We developed a novel ultrasound-shockwave catheter that combines flowing liquid and ultrasound to suppress bubble shielding and enhance lithotripsy efficiency. Experimental results confirm the bubble shielding effect in IVL, which can be mitigated by flowing liquid or ultrasound. Fracture experiments using Ultracal-30 as phantoms demonstrate the ultrasound emitted after 10 ms of shockwave generation and combines with bubbles can enhance lithotripsy efficiency. Specifically, the addition of ultrasound and bubbles reduced the mass percentage of fragments larger than 4.5 mm by 38.56 % compared to the control. Spectrum analysis of ultrasound reveals cavitation's role in improving lithotripsy efficiency. In summary, while bubbles initially attenuate shockwave intensity and reduce lithotripsy efficiency, their combination with ultrasound-induced cavitation enhances treatment outcomes.

Intraplaque Hemorrhage and Plaque Ulceration Are More Likely in Patients with Symptomatic Mild-to-Moderate Carotid Artery Stenosis than in Symptomatic and Asymptomatic High-Grade Stenosis: A Retrospective Cohort Study

BACKGROUND

To compare a cohort of symptomatic patients with mild-to-moderate (<70%) carotid artery stenosis (CAS) with those patients with high-grade (≥70%) CAS (symptomatic and asymptomatic) to assess for markers that places them at a higher risk for stroke.

METHODS

A propensity score-matched cohort study design for all patients who underwent carotid revascularization between 2015 and 2024 was utilized to compare the high-grade (≥70%) symptomatic and asymptomatic carotid stenosis groups against the mild to moderate (<70%) symptomatic carotid stenosis group. Matched variables included age, sex, and atrial fibrillation. Vulnerable plaque was defined as the presence of intraplaque hemorrhage, ulceration, lipid necrotic core, and inflammation on cross-sectional imaging. Images assessed included computed tomography angiography and magnetic resonance angiography with vessel wall imaging. Odds ratios (ORs) were then calculated to assess for risk of vulnerable features present on cross-sectional imaging before carotid intervention.

RESULTS

There were 58 patients in each cohort matched and analyzed. In our cohort of interest, there were fewer patients with diabetes and higher proportion of hyperlipidemia compared to those patients who were symptomatic with ≥70% CAS. Further, there were fewer patients with diabetes and none on dialysis compared to our asymptomatic high-grade stenosis group. The OR of presenting with vulnerable features in our mild-to-moderate stenosis symptomatic group was 5.85 (95% confidence interval (CI) 1.74-19.60, P = 0.002) compared to the high-grade asymptomatic stenosis patients and 7.52 (95% CI 3.22-17.66, P < 0.001) compared to the high-grade symptomatic stenosis patients. Additionally, the symptomatic <70% stenosis group had higher odds of intraplaque hemorrhage (OR 4.91, 95% CI 1.80-13.78, P < 0.001) and ulcerated plaque (OR 8.93, 95% CI 2.47-32.82, P < 0.001) compared to the asymptomatic ≥70% group, as well as increased odds of intraplaque hemorrhage (OR 4.14, 95% CI 1.59-10.74, P = 0.002) and ulcerated plaque (OR 5.16, 95% CI 1.77-15.03, P = 0.001) compared to the symptomatic ≥70% group. Composite outcomes of stroke, myocardial infarction, and death were no different in 30-day and mid-term follow-up.

CONCLUSION

High-risk plaque features on cross-sectional imaging studies may justify a short-term more aggressive medical management and/or early intervention in patients with mild-to-moderate CAS, even when luminal narrowing alone would not typically warrant such measures. As such, use of advanced imaging to assess for plaque characteristics may allow for improved risk stratification and guide earlier management of this patient population.

Predicting vulnerable coronary arteries: A combined radiomics-biomechanics approach

BACKGROUND AND OBJECTIVE

Nowadays, vulnerable coronary plaque detection from coronary computed tomography angiography (CCTA) is suboptimal, although being crucial for preventing major adverse cardiac events. Moreover, despite the suggestion of various vulnerability biomarkers, encompassing image and biomechanical factors, accurate patient stratification remains elusive, and a comprehensive approach integrating multiple markers is lacking. To this aim, this study introduces an innovative approach for assessing vulnerable coronary arteries and patients by integrating radiomics and biomechanical markers through machine learning methods.

METHODS

The study included 40 patients (7 high-risk and 33 low-risk) who underwent both CCTA and coronary optical coherence tomography (OCT). The dataset comprised 49 arteries (with 167 plaques), 7 of which (with 28 plaques) identified as vulnerable by OCT. Following image preprocessing and segmentation, CCTA-based radiomic features were extracted and a finite element analysis was performed to compute the biomechanical features. A novel machine learning pipeline was implemented to stratify coronary arteries and patients. For each stratification task, three independent predictive models were developed: a radiomic, a biomechanical and a combined radiomic-biomechanical model. Both k-nearest neighbors (KNN) and decision tree (DT) classifiers were considered.

RESULTS

The best radiomic model (KNN) detected all 7 vulnerable arteries and patients and was associated with a balanced accuracy of 0.86 (sensitivity=1, specificity=0.71) for the artery model and of 0.83 (sensitivity=1, specificity=0.67) for the patient model. The best biomechanical model (DT) detected 6 over 7 vulnerable arteries and patients and remarkably increased the specificity, resulting in a balanced accuracy of 0.89 (sensitivity=0.86, specificity=0.93) for the artery model and of 0.88 (sensitivity=0.86, specificity=0.91) for the patient model. Notably, the combined approach optimized the performance, with an increase in the balance accuracy up to 0.94 for the artery model and up to 0.92 for the patient model, being associated with sensitivity=1 and high specificity (0.88 and 0.85 for artery and patient models, respectively).

CONCLUSION

This investigation highlights the promise of radio-mechanical coronary artery phenotyping for patient stratification. If confirmed from larger studies, our approach enables a more personalized management of the disease, with the early identification of high-risk individuals and the reduction of unnecessary interventions for low-risk individuals.

Myocardial Fibroblast Activation After Acute Myocardial Infarction: A Positron Emission Tomography and Magnetic Resonance Study

BACKGROUND

Myocardial fibrosis is a key healing response after myocardial infarction driven by activated fibroblasts. Gallium-68-labeled fibroblast activation protein inhibitor ([68Ga]-FAPI) is a novel positron-emitting radiotracer that binds activated fibroblasts.

OBJECTIVES

The aim of this study was to investigate the intensity, distribution, and time-course of fibroblast activation after acute myocardial infarction.

METHODS

A total of 40 patients with acute myocardial infarction underwent hybrid [68Ga]FAPI-46 positron emission tomography and cardiac magnetic resonance and were compared with matched control subjects (n = 19) and those with chronic (>2 years) myocardial infarction (n = 20). Intensity of [68Ga]FAPI-46 uptake was quantified by maximum target-to-background ratio (TBRmax). Burdens of fibroblast activation and scar were assessed by percent myocardial involvement of [68Ga]FAPI-46 uptake and late gadolinium enhancement, respectively.

RESULTS

Myocardial [68Ga]FAPI-46 uptake was observed in the acute infarct and peri-infarct regions that exceeded the extent of late gadolinium enhancement (burden 27.8% ± 12.4% vs 15.2% ± 10.6%; P < 0.001). One-third of patients also demonstrated right ventricular involvement. Myocardial [68Ga]FAPI-46 uptake was most intense at 1 and 2 weeks before declining at 4 and 12 weeks (TBRmax 4.0 ± 1.1, 3.7 ± 1.0, 3.1 ± 0.8, and 2.7 ± 0.7; P < 0.001). In comparison with control subjects, increased [68Ga]FAPI-46 uptake was observed in chronic (7 ± 6 years ago) infarcts at lower intensity than acute infarction (TBRmax 1.2 ± 0.1 vs 1.7 ± 0.5 vs 4.0 ± 1.1; P < 0.001). Baseline [68Ga]FAPI-46 burden correlated with lower left ventricular ejection fraction (r = -0.606), higher indexed left ventricular end-diastolic volume (r = 0.572), and higher scar burden (r = 0.871) at 1 year (P < 0.001 for all). Increased remote myocardial [68Ga]FAPI-46 uptake was associated with left ventricular dilatation and systolic dysfunction.

CONCLUSIONS

Myocardial fibroblast activation peaks within a week of acute myocardial infarction and extends beyond the infarct region. It declines slowly with time, persists for years, and is associated with subsequent left ventricular remodeling. (PROFILE-MI-The FAPI Fibrosis Study; NCT05356923).

Analysis and validation of biomarkers and immune cell infiltration profiles in unstable coronary atherosclerotic plaques using bioinformatics and machine learning

Introduction

Decreased stability of coronary atherosclerotic plaques correlates with a heightened risk of acute coronary syndrome (ACS). Thus, early diagnosis and treatment of unstable plaques are imperative in averting adverse cardiovascular events. This study aims to identify diagnostic biomarkers for unstable coronary atherosclerotic plaques and investigate the role of immune cell infiltration in their formation.

Methods

The datasets GSE163154 and GSE111782, obtained from the gene expression omnibus (GEO) database, were amalgamated for bioinformatics analysis, using the dataset GSE43292 as a test set. Sequentially, we performed principal component analysis (PCA), differential gene expression analysis, enrichment analysis, weighted gene co-expression network analysis (WGCNA), utilized a machine learning algorithm to screen key genes, conducted receiver operating characteristic (ROC) curve analysis and nomogram model to assess biomarker diagnostic efficacy, validated the biomarkers, and analyzed immune cell infiltration.

Results

In conclusion, enrichment analyses demonstrate that genes are significantly enriched in inflammatory and immune-related pathways. We identified HSPA2 and GEM as key genes and validated them experimentally. Significant differences existed in immune cell infiltration between subgroups. Additionally, HSPA2 and GEM showed significant associations with a wide range of immune cells.

Discussion

HSPA2 and GEM can function as diagnostic biomarkers for unstable coronary atherosclerotic plaques. In combination with immune cell infiltration analyses, our study provides new insights into the future study of unstable plaque occurrence and molecular mechanisms.

Vulnerable or High-Risk Plaque: A JACC: Cardiovascular Imaging Position Statement

The concept of high-risk plaque emerged from pathologic and epidemiologic studies 3 decades ago that demonstrated plaque rupture with thrombosis as the predominant mechanism of acute coronary syndrome and sudden cardiac death. Thin-cap fibroatheroma, a plaque with a large lipidic core covered by a thin fibrous cap, is the prototype of the rupture-prone plaque and has been traditionally defined as "vulnerable plaque." Although knowledge on the pathophysiology of plaque instability continues to grow, the risk profile of our patients has shifted and the character of atherosclerotic disease has evolved, partly because of widespread use of lipid-lowering therapies and other preventive measures. In vivo intracoronary imaging studies indicate that superficial erosion causes up to 40% of acute coronary syndromes. This changing landscape calls for broader perspective, expanding the concept of high-risk plaque to the precursors of all major substrates of coronary thrombosis beyond plaque rupture. Other factors to take into consideration include dynamic changes in plaque composition, the importance of plaque burden, inflammatory activation (both local and systemic), healing mechanisms, regional hemodynamic pattern, properties of the fluid phase of blood, and the amount of myocardium at risk subtended by a lesion. Rather than the traditional focus limited to the thin-cap fibroatheroma, the authors advocate a more comprehensive approach that considers both morphologic features and biological activity of plaques and blood. This position paper highlights the challenges to the usual concept of high-risk plaque, proposes a broader definition, and analyzes its key morphologic features, the technological progress of plaque imaging (particularly using intracoronary imaging techniques), advances in pharmacologic therapies for plaque regression and stabilization, and the feasibility and efficacy of focal interventional treatments including preemptive plaque sealing.

Prognostic Value of Multiple Complete Blood Count-Derived Indices in Intermediate Coronary Lesions

Complete blood count (CBC)-derived indices have been proposed as reliable inflammatory biomarkers to predict outcomes in the context of coronary artery disease. These indices have yet to be thoroughly validated in patients with intermediate coronary stenosis. Our study included 1527 patients only with intermediate coronary stenosis. The examined variables were neutrophil-lymphocyte ratio (NLR), derived NLR, monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), systemic immune inflammation index (SII), system inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI). The primary endpoint was the composite of major adverse cardiovascular events (MACEs), including all-cause death, non-fatal myocardial infarction, and unplanned revascularization. Over a follow-up of 6.11 (5.73-6.55) years, MACEs occurred in 189 patients. Receiver operator characteristic curve analysis showed that SIRI outperformed other indices with the most significant area under the curve. In the multivariable analysis, SIRI (hazard ratio [HR] 1.588, 95% confidence interval [CI] 1.138-2.212) and AISI (HR 1.673, 95% CI 1.217-2.300) were the most important prognostic factors among all the indices. The discrimination ability of each index was strengthened in patients with less burden of modifiable cardiovascular risk factors. SIRI also exhibited the best incremental value beyond the traditional cardiovascular risk model.

End-to-end deep-learning model for the detection of coronary artery stenosis on coronary CT images

PURPOSE

We examined whether end-to-end deep-learning models could detect moderate (≥50%) or severe (≥70%) stenosis in the left anterior descending artery (LAD), right coronary artery (RCA) or left circumflex artery (LCX) in iodine contrast-enhanced ECG-gated coronary CT angiography (CCTA) scans.

METHODS

From a database of 6293 CCTA scans, we used pre-existing curved multiplanar reformations (CMR) images of the LAD, RCA and LCX arteries to create end-to-end deep-learning models for the detection of moderate or severe stenoses. We preprocessed the images by exploiting domain knowledge and employed a transfer learning approach using EfficientNet, ResNet, DenseNet and Inception-ResNet, with a class-weighted strategy optimised through cross-validation. Heatmaps were generated to indicate critical areas identified by the models, aiding clinicians in understanding the model's decision-making process.

RESULTS

Among the 900 CMR cases, 279 involved the LAD artery, 259 the RCA artery and 253 the LCX artery. EfficientNet models outperformed others, with EfficientNetB3 and EfficientNetB0 demonstrating the highest accuracy for LAD, EfficientNetB2 for RCA and EfficientNetB0 for LCX. The area under the curve for receiver operating characteristic (AUROC) reached 0.95 for moderate and 0.94 for severe stenosis in the LAD. For the RCA, the AUROC was 0.92 for both moderate and severe stenosis detection. The LCX achieved an AUROC of 0.88 for the detection of moderate stenoses, though the calibration curve exhibited significant overestimation. Calibration curves matched probabilities for the LAD but showed discrepancies for the RCA. Heatmap visualisations confirmed the models' precision in delineating stenotic lesions. Decision curve analysis and net reclassification index assessments reinforced the efficacy of EfficientNet models, confirming their superior diagnostic capabilities.

CONCLUSION

Our end-to-end deep-learning model demonstrates, for the LAD artery, excellent discriminatory ability and calibration during internal validation, despite a small dataset used to train the network. The model reliably produces precise, highly interpretable images.

Enhancing cardiovascular risk stratification: Radiomics of coronary plaque and perivascular adipose tissue - Current insights and future perspectives

Radiomics, the quantitative extraction and mining of features from radiological images, has recently emerged as a promising source of non-invasive image-based cardiovascular biomarkers, potentially revolutionizing diagnostics and risk assessment. This review explores its application within coronary plaques and pericoronary adipose tissue, particularly focusing on plaque characterization and cardiac events prediction. By shedding light on the current state-of-the-art, achievements, and prospective avenues, this review contributes to a deeper understanding of the evolving landscape of radiomics in the context of coronary arteries. Finally, open challenges and existing gaps are emphasized to underscore the need for future efforts aimed at ensuring the robustness and reliability of radiomics studies, facilitating their clinical translation.

Fractal geometry of culprit coronary plaque images within optical coherence tomography in patients with acute coronary syndrome vs stable angina pectoris

The main cause of acute coronary syndrome (ACS) is plaque rupture and thrombus formation. However, it has not been fairly successful to identify vulnerable plaque to rupture using conventional parameters of intravascular imaging modalities. Fractal analysis is one of the mathematical models to examine geometrical features of picture image using a specific parameter called as fractal dimension (FD) which suggests geometric complexity of the image. This study examined FD of the optical coherence tomography (OCT)-derived images of the culprit plaque in patients with ACS vs stable angina pectoris (SAP) to evaluate the feasibility of FD for identifying vulnerable coronary plaques prone to provoke ACS distinguished from stable plaques only provoking SAP. We examined 65 cases (34 ACS patients, 31 SAP patients) in which the culprit lesion was imaged by OCT before percutaneous coronary intervention in patients with ACS and SAP. The culprit plaque lesion in the ACS group had a significantly larger mean lipid arc (203.8 ± 39.4° vs 152.3 ± 34.5°, p < 0.001) and a larger lipid plaque length (12.6 ± 5.1 mm vs 7.7 ± 2.7 mm, p < 0.001) and a thinner fibrous cap thickness (75.3 ± 22.3 μm vs 134.8 ± 53.2 μm, p < 0.001) than those in the SAP group. The prevalence of OCT-derived macrophage infiltration (Mph) in the entire culprit coronary vessel as well as that of the OCT-derived thin-cap fibroatheroma (TCFA) at the culprit lesion were significantly greater in the ACS group than those in the SAP group, respectively (Mph: 61.8% vs 35.5%, p = 0.048; TCFA: 44.1% vs 6.4%, p < 0.001). The FD of culprit plaque in the ACS group was significantly greater than in the SAP group (2.401 ± 0.073 vs 2.341 ± 0.051, p < 0.001). In multivariate regression analysis, the presence of Mph was a significant determinant of FD (regression coefficient estimate 0.049, CI 0.018-0.079, p = 0.002). The FD of OCT-derived image of culprit coronary plaque in the ACS group was significantly greater than that in the SAP group, indicating that the culprit plaque in ACS were structurally more complex. Therefore, fractal analysis of coronary OCT images might be clinically useful for identifying coronary plaques prone to provoke ACS.

Emerging Imaging Techniques for Atherosclerosis in Systemic Immune-Mediated Inflammatory Conditions

Atherosclerosis affects patients with systemic immune-mediated inflammatory diseases at an increased rate compared with the general population. In recent years, our understanding of the pathophysiology of atherosclerosis has advanced considerably. Nevertheless, cardiovascular imaging modalities that can adequately assess the biological background of atherosclerosis have not reached widespread clinical adoption. Novel developments in cardiac imaging have the potential to enhance the diagnostic yield of these modalities further while providing essential insights into the anatomy, composition, and biology of atherosclerotic lesions. In this review, we highlight some of the latest developments in the field for the evaluation of atherosclerosis using advances in echocardiography, computed tomography, positron emission tomography, and cardiovascular magnetic resonance. Additionally, we discuss evidence specifically in patients with immune-mediated inflammatory diseases and outline unmet research needs for future development.

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.

The Role of Coronary Computed Tomography Angiography in the Diagnosis, Risk Stratification, and Management of Patients with Diabetes and Chest Pain

Coronary artery disease (CAD) affects over 200 million individuals globally, accounting for approximately 9 million deaths annually. Patients living with diabetes mellitus exhibit an up to fourfold increased risk of developing CAD compared to individuals without diabetes. Furthermore, CAD is responsible for 40 to 80 percent of the observed mortality rates among patients with type 2 diabetes. Patients with diabetes typically present with non-specific clinical complaints in the setting of myocardial ischemia, and as such, it is critical to select appropriate diagnostic tests to identify those at risk for major adverse cardiac events (MACEs) and for determining optimal management strategies. Studies indicate that patients with diabetes often exhibit more advanced atherosclerosis, a higher calcified plaque burden, and smaller epicardial vessels. The diagnostic performance of coronary computed tomographic angiography (CCTA) in identifying significant stenosis is well-established, and as such, CCTA has been incorporated into current clinical guidelines. However, the predictive accuracy of obstructive CAD in patients with diabetes has been less extensively characterized. CCTA provides detailed insights into coronary anatomy, plaque burden, epicardial vessel stenosis, high-risk plaque features, and other features associated with a higher incidence of MACEs. Recent evidence supports the efficacy of CCTA in diagnosing CAD and improving patient outcomes, leading to its recommendation as a primary diagnostic tool for stable angina and risk stratification. However, its specific benefits in patients with diabetes require further elucidation. This review examines several key aspects of the utility of CCTA in patients with diabetes: (i) the diagnostic accuracy of CCTA in detecting obstructive CAD, (ii) the effect of CCTA as a first-line test for individualized risk stratification for cardiovascular outcomes, (iii) its role in guiding therapeutic management, and (iv) future perspectives in risk stratification and the role of artificial intelligence.

[Aortitis]

Aortitis is a rare disease entity of unknown prevalence. Primary aortitis mainly affects the thoracic aorta. They are most often diagnosed on imaging by grade III 18-FDG uptake of the aortic wall on PET, or by circumferential thickening>2.2mm on CT or MRI with late-stage contrast. More rarely, aortitis is histologically proven, as in some cases of clinically isolated aortitis discovered after planned aortic aneurysm surgery or during aortic dissection surgery. The most common histological types are granulomatous/giant cell or lymphoplasmacytic. Clinical signs associated with aortitis are often non-specific: asthenia, fever, dry cough, chest, back, lumbar or abdominal pain. Aortitis can be divided into different etiological categories: primary aortitis, which includes vasculitis with a preferential or exclusive tropism for the aortic wall, aortitis secondary to systemic or iatrogenic diseases, and infectious aortitis. The main etiologies of primary aortitis are giant cell arteritis (GCA), Takayasu arteritis (TA) or clinically isolated aortitis. Aortitis secondary to systemic diseases is seen in atrophying polychondritis, systemic lupus and inflammatory rheumatic diseases such as spondyloarthropathy and rheumatoid arthritis. In both ACG and AT, aortitis is a negative factor, characterized by a higher risk of relapse, cardiovascular complications and increased mortality. The management of aortitis is insufficiently codified, and relies on the control of cardiovascular risk factors, with particular monitoring of blood pressure and LDL cholesterol, and on corticosteroid therapy and immunosuppressive drugs, the use of which will depend on the disease associated with the aortitis, the initial severity and comorbidities.

Hemin-induced platelet activation is regulated by the ACKR3 chemokine surface receptor and has implications for passivation of vulnerable atherosclerotic plaques

In vulnerable atherosclerotic plaques, intraplaque hemorrhages (IPH) result in hemolysis of red blood cells and release of hemoglobin and free hemin. Hemin activates platelets and leads to thrombosis. Agonism of the inhibitory platelet receptor ACKR3 inhibits hemin-dependent platelet activation and thrombus formation. To characterize the effect of hemin and ACKR3 agonism on isolated human platelets, multi-color flow cytometry and classical experimental setup such as light transmission aggregometry and a flow chamber assay were used. Hemin induces platelet aggregation and ex vivo platelet-dependent thrombus formation on immobilized collagen under a low shear rate of 500 s-1, indicating that free hemin is a strong activator of platelet-dependent thrombosis. Recently, we described that ACKR3 is a prominent inhibitory receptor of platelet activation. Specific ACKR3 agonists but not conventional antiplatelet compounds such as COX-1 inhibitor (indometacin), ADP-receptor blocker (cangrelor), or PAR1 inhibitor (ML161) inhibit both hemin-dependent aggregation and thrombus formation. To further characterize the effect of hemin on platelet subpopulations, we established a multi-color flow cytometry assay. We found that hemin induces procoagulant (CD42bpos/PAC-1neg/AnnexinVpos), aggregatory (CD42bpos/PAC-1pos/AnnexinVneg), and inflammatory (CD42bpos/CXCR4pos/ACKR3pos/AnnexinVpos) platelet subpopulations. Treatment with ACKR3 agonists significantly decreased the formation of procoagulant and ACKR3pos platelets in response to hemin. We conclude that hemin is a strong activator for the formation of procoagulant platelets and thrombus formation which is dependent on the function of ACKR3. Activation of ACKR3 using specific agonists may offer a therapeutic strategy to regulate the vulnerability of atherosclerotic plaques in areas of IPH.

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.

Significance of myeloperoxidase, pentraxin-3 and soluble urokinase plasminogen activator receptor determination in patients with moderate carotid artery stenosis

We investigated serum concentrations of specific inflammatory parameters in patients with significant carotid artery stenosis (CAS) of 50-99%, with an additional focus on patients with moderate stenosis (50-69%), in terms of both symptomatic status and plaque morphology, to determine whether there are certain parameters that can be associated with plaque instability before the progression of CAS to a high degree. The study included 119 CAS patients, 29 of whom had moderate stenosis, and 46 controls. Ultrasonography of the carotid arteries was performed using color flow Doppler and B-mode duplex ultrasound, and serum inflammatory parameters were measured using commercially available enzyme immunoassays. When comparing patients with 50-99% stenosis, only serum amyloid A (SAA) was higher in symptomatic patients, while in the group of patients with 50-69% stenosis, myeloperoxidase (MPO) was higher and pentraxin-3 (PTX-3) was lower in symptomatic compared to asymptomatic patients, and soluble urokinase plasminogen activator receptor (suPAR) was higher in patients with carotid plaque of unstable compared to stable morphology. Our results suggest that the importance of different inflammatory parameters in patients with moderate CAS is not the same as in CAS patients in general, and therefore their separate investigation in patients with high and moderate stenosis may be beneficial. SAA has the potential to be further considered in research to predict CAS symptom risk. There is a possibility that MPO and PTX-3 play a role in the development of CAS symptoms originating from less stenotic plaques and that suPAR is involved in the destabilisation of such plaques.

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.

Multimodal Intravascular Imaging of the Vulnerable Coronary Plaque

Vulnerable coronary plaques are atherosclerotic lesions which, due to their specific phenotype, are prone to plaque rupture and to cause acute coronary syndromes, with subsequent relevant morbidity and mortality. Strategies to break the chain link between plaque vulnerability and adverse clinical events include optimized pharmacologic prevention and potentially also preemptive percutaneous coronary interventions (previously defined as "plaque sealing" or "plaque passivation"). Various morphologic features of the vulnerable plaques have been described, including aspects regarding the large necrotic lipid content, the thin fibrous cap, the presence and extent of the presence of calcifications with small size and calcification angle, and as well as the large macrophage infiltration within the plaque. The detection of these features of plaque vulnerability is possible with intravascular imaging modalities such as intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS), and optical coherence tomography (OCT). This review explores the peculiarities of these three imaging modalities for the detection of vulnerable coronary plaque features.

Impact of Implementation of a Region-Wide Low-Density Lipoprotein Cholesterol Management Clinical Pathway for the Secondary Prevention of Acute Myocardial Infarction

BACKGROUND

Aggressive lipid-lowering therapy is important for secondary prevention of acute myocardial infarction (AMI). The recommended target for low-density lipoprotein cholesterol (LDL-C) of <70 mg/dL is often not achieved. To address this gap, we implemented a clinical pathway in all hospitals that perform percutaneous coronary interventions (PCI) with primary care physicians in Nagasaki and aimed to validate the effectiveness of this pathway in an acute setting.

METHODS AND RESULTS

This retrospective cohort study included medical records extracted from 8 hospitals in Nagasaki, Japan, where PCI was performed for patients with AMI. The index date was defined as the date of hospitalization for AMI between July 1, 2021, and February 28, 2023. The primary outcome was the rate of achieving LDL-C <70 mg/dL at discharge. The median baseline LDL-C level at admission was 121 mg/dL (n=226) in the pre-implementation group and 116 mg/dL (n=163) in the post-implementation group. In the post-implementation group, 131 patients were treated using the clinical pathway. The rate of achieving LDL-C <70 mg/dL at discharge increased significantly from 37.2% before implementation to 54.6% after implementation. Logistic regression analysis revealed a positive correlation between the implementation of the clinical pathway and achieving LDL-C <70 mg/dL.

CONCLUSIONS

Implementation of a region-wide clinical pathway for LDL-C management significantly improved the rate of intensive lipid-lowering therapy and the achievement of LDL-C targets.

Histological validation of three-dimensional variable flip angle turbo spin echo multi-contrast magnetic resonance vessel wall imaging in characterizing carotid vulnerable atherosclerotic plaques

BACKGROUND

Accurate assessment of the vulnerability of carotid atherosclerotic plaques is crucial for stroke prevention. The three-dimensional (3D) magnetic resonance (MR) vessel wall imaging (VWI) has been increasingly employed to evaluate carotid plaques due to its extensive coverage and isotropic high spatial resolution. However, the accuracy of such techniques lacks validation by histology. Therefore, this study aims to validate the accuracy of 3D multi-contrast MR VWI with variable-flip-angle (VFA) and turbo spin echo (TSE) readout in identifying vulnerable carotid plaques, using histological analysis as a reference.

METHODS

Twenty-one male patients (mean age: 64.4 ± 7.2 years old) scheduled for carotid endarterectomy (CEA) were recruited in this study. All patients underwent carotid multi-contrast MR VWI, including 3D T1- and T2-weighted VFA-TSE sequences, as well as 3D time of flight (TOF) MR angiography (MRA), using a 3.0T MR system before surgery. Histological processing was performed for carotid plaque specimens. The presence or absence, along with the area measurements, of lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH), and calcifications (CA) were independently evaluated on both MR images and histological sections. Cohen's kappa (κ) analysis was utilized to determine the agreement between 3D multi-contrast MR VWI and histology in identifying carotid plaque compositions before and after excluding compositions bellow certain size threshold. Spearman's correlation analysis was also conducted to assess the agreement in quantifying plaque compositions.

RESULTS

A total of 81 slices of MR images were successfully matched with histological sections. Moderate to almost perfect agreements were observed between 3D MR VWI and histology in the identification of LRNC (κ: 0.85 and 0.89), IPH (κ: 0.65 and 0.69), and CA (κ: 0.46 and 0.62) before and after excluding compositions smaller than 0.79 mm2. Strong to very strong correlations were found in the quantification of plaque compositions including LRNC (r=0.88), IPH (r=0.80), and CA (r=0.74) between MR imaging and histology.

CONCLUSION

The 3D VFA-TSE multi-contrast MR VWI is capable of accurately characterizing vulnerable carotid atherosclerotic plaques.

Construction of vulnerable plaque prediction model based on multimodal vascular ultrasound parameters and clinical risk factors

The rupture of vulnerable plaque (VP) are significant pathogenic factors leading to cardiovascular and cerebrovascular diseases. This study aims to construct a vulnerable plaque prediction model (VPPM) by combining multimodal vascular ultrasound parameters and clinical risk factors, and to validate it. A total of 196 atherosclerotic patients who underwent carotid endarterectomy (CEA) from January 2017 to December 2023 were collected and divided into a modeling group (n = 137) and a validation group (n = 59). Clinical information including: hypertension, diabetes, smoking history, and body mass index (BMI) was included in the analysis. All patients underwent carotid ultrasound and contrast-enhanced ultrasound (CEUS) examination after admission, with main ultrasound parameters including thickness, echogenicity types, stenosis degree, and CEUS neovascularization grading of plaques. Independent risk factors for VP in CEA patients were screened through binary Logistic regression analysis, and a prediction model was established along with a nomogram. The calibration curve, receiver-operating characteristic curve (ROC), and decision curve analysis (DCA) were employed to assess the calibration, diagnostic efficacy, and clinical utility of the VPPM model. There were no significant statistical differences in multimodal vascular ultrasound parameters and clinical risk factors between the modeling and validation groups (P > 0.05). Binary Logistic regression analysis identified plaque thickness, echo type, CEUS neovascularization grading, BMI, and smoking history as 5 variables entering the prediction model. The VPPM model showed good diagnostic efficacy, with an area under the ROC curve of 0.959 (95% CI 0.915-0.999). Using the nomogram with a VPPM risk assessment score of 135.42 as the diagnostic cutoff value in the modeling group, the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and Youden index were 88.1%, 94.1%, 14.98, 0.126, and 82.2%, respectively. In the DCA curve, the VPPM model curve was significantly better than two extreme lines, indicating good clinical utility. The VPPM model constructed by integrating multimodal ultrasound parameters and clinical key risk factors has high diagnostic efficacy and is expected to be an auxiliary tool for clinical diagnosis of vulnerable plaques.

PCSK9 expression in fibrous cap possesses a marker for rupture in advanced plaque

BACKGROUND

To date, PCSK9 inhibitors are well known for eliminating cardiac and cerebral artery ischemia events by lowering the serum lipid level. However, the pathophysiological value of in-plaque PCSK9 expression is still unclear.

METHODS

Advanced plaques removed by carotid endarterectomy were sectioned and stained to identify the PCSK9 expression pattern and its co-expression with rupture-relevant markers. To investigate the correlation of PCSK9 expression with regional blood shear flow, hemodynamic characteristics were analyzed using computational fluid dynamics, and representative parameters were compared between PCSK9 positive and negative staining plaques. To explore this phenomenon in vitro, human aortic vascular smooth muscle cells were used to overexpress and knock down PCSK9. The impacts of PCSK9 modulations on mechanical sensor activity were testified by western blot and immunofluorescence. Real-time polymerase chain reaction was used to evaluate the transcription levels of downstream rupture-prone effectors.

RESULTS

PCSK9 distribution in plaque preferred cap and shoulder regions, residing predominantly in smooth muscle actin-positive cells. Cap PCSK9 expression correlated with fibrous cap thickness negatively and co-expressed with MMP-9, both pointing to the direction of plaque rupture. A hemodynamic profile indicated a rupture-prone feature of cap PCSK9 expression. In vitro, overexpression and knockdown of PCSK9 in human aortic vascular smooth muscle cells has positive modulation on mechanical sensor Yes-associated protein 1 (YAP) activity and transcription levels of its downstream rupture-prone effectors. Serial section staining verified in situ colocalization among PCSK9, YAP, and downstream effectors.

CONCLUSIONS

Cap PCSK9 possesses a biomarker for rupture risk, and its modulation may lead to a novel biomechanical angle for plaque interventions.

Flow shear force destabilizes carotid plaques by affecting CHOP and GRP78 proteins

BACKGROUND

Various factors, including blood, inflammatory, infectious, and immune factors, can cause ischemic stroke. However, the primary cause is often the instability of cervical arteriosclerosis plaque. It is estimated that 18-25% of ischemic strokes are caused by the rupture of carotid plaque.1 Plaque stability is crucial in determining patient prognosis. Developing a highly accurate, non-invasive, or minimally invasive technique to assess carotid plaque stability is crucial for diagnosing and treating stroke.Previous research by our group has demonstrated that the expression levels of CHOP (C/EBP homologous protein) and GRP78 (glucose-regulated protein 78) are correlated with the stability of atherosclerotic plaques.2 OBJECT: This research assesses changes in GRP78 and CHOP expressions in human umbilical vein endothelial cells(HUVEC) following experiments within the hemodynamic influencing factors test system. Additionally, it includes conducting an empirical study on the impact of blood flow shear force on the stability of human carotid atherosclerotic plaques. The objective is to explore the implications of blood flow shear force on the stability of carotid atherosclerotic plaques.

METHOD

The hemodynamic influencing factors test bench system was configured with low (Group A, 4 dyns/cm²), medium (Group B, 8 dyns/cm²), and high shear force groups (Group C, 12 dyns/cm²). Relative expression levels of GRP78 and CHOP proteins in human umbilical vein endothelial cells were measured using Western blot analysis, and quantitative analysis of GRP78 and CHOP mRNA was conducted using RT-qPCR. Meanwhile, plaques from 60 carotid artery patients, retrieved via Carotid Endarterectomy (CEA), were classified into stable (S) and unstable (U) groups based on pathological criteria. Shear force at the carotid bifurcation was measured preoperatively using ultrasound. Western blot and RT-qPCR were used to analyze the relative expression levels of GRP78 and CHOP proteins and mRNA, respectively, in the plaque specimens from both groups.

RESULT

Expression levels of GRP78, CHOP proteins, and their mRNAs were assessed in groups A, B, and C via Western blot and RT-qPCR. Results showed that in the low-shear group, all markers were elevated in group A compared to groups B and C. Statistical analysis revealed significantly lower shear forces at the carotid bifurcation in group U compared to group S. In group U plaques, GRP78 and CHOP expressions were significantly higher in group U than in group S.

CONCLUSION

Blood flow shear forces variably affect the expression of GRP78 and CHOP proteins, as well as their mRNA levels, in vascular endothelial cells. The lower the shear force and fluid flow rate, the higher the expression of GRP78 and CHOP, potentially leading to endoplasmic reticulum stress(ERS), which may destabilize the plaque.

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.

The Characteristics of Coronary Artery Lesions in COVID-19 Infected Patients With Coronary Artery Disease: An Optical Coherence Tomography Study

COVID-19 may predispose patients to cardiac injuries but whether COVID-19 infection affects the morphological features of coronary plaques to potentially influence the outcome of patients with coronary artery disease (CAD) remains unknown. By using optical coherence tomography (OCT), this study compared the characteristics of coronary plaque in patients with CAD with/without COVID-19 infection. The 206 patients were divided into 2 groups. The COVID-19 group had 113 patients between December 7, 2022, and March 31, 2023, who received OCT assessment after China decided to lift the restriction on COVID-19 and had a history of COVID-19 infection. The non-COVID-19 group had 93 patients without COVID-19 infection who underwent OCT before December 7, 2022. The COVID-19 group demonstrated a higher incidence of plaque ruptures (53.1% vs 38.7%, p = 0.039), erosions (28.3% vs 11.8%, p = 0.004), fibrous (96.5% vs 89.2%, p = 0.041) and diffuse lesions (73.5% vs 50.5%, p <0.001) compared with the non-COVID-19 group, whereas non-COVID-19 group exhibited a higher frequency of cholesterol crystals (83.9% vs 70.8%, p = 0.027), deep calcifications (65.6% vs 51.3%, p = 0.039) and solitary lesions (57.0% vs 34.5%, p = 0.001). Kaplan-Meier survival analysis revealed a significantly lower major adverse cardiac events-free probability in the COVID-19 group (91.6% vs 95.5%, p = 0.006) than in the non-COVID-19 group. In conclusion, OCT demonstrated that COVID-19 infection is associated with coronary pathological changes such as more plaque ruptures, erosions, fibrosis, and diffuse lesions. Further, COVID-19 infection is associated with a higher propensity for acute coronary events and a higher risk of major adverse cardiac events in patients with CAD.

Neutrophil extracellular traps mediate the crosstalk between plaque microenvironment and unstable carotid plaque formation

The development of unstable carotid atherosclerotic plaques is associated with the induction of neutrophil extracellular traps (NETs) via the activation of diverse inflammatory mediators in the circulating bloodstream. However, the underlying mechanisms through which NETs influence the microenvironment of atherosclerotic plaques and contribute to the development of unstable carotid plaques remain largely elusive. The objective of this study was to elucidate the role of myeloid differentiation protein 1 (MD-1, LY86)-induced NETs underlying the crosstalk between unstable plaque formation and the plaque microenvironment. We employed bioinformatics analysis to identify key genes associated with carotid-unstable plaque, followed by comprehensive validation using various experimental approaches on tissue specimens and plasma samples classified based on pathological characteristics. Patients with carotid-unstable plaques exhibited elevated plasma concentrations of MD-1 (LY86), while patients with stable plaques demonstrated comparatively lower levels. Furthermore, soluble MD-1 was found to induce the formation of NETs through activation of Toll-like receptor signaling pathway. The proliferative and immature vascularization effects of NETs on endothelial cells, as well as their inhibitory impact on cell migration, are directly correlated with the concentration of NETs. Additionally, NETs were found to activate the NF-κB signaling pathway, thereby upregulating ICAM1, VCAM1, MMP14, VEGFA, and IL6 expression in both Human umbilical vein endothelial cells (HUVECs) and HAECs. Subsequently, a significant increase in intraplaque neovascularization by NETs results in poor carotid plaque stability, and NETs in turn stimulate macrophages to produce more MD-1, generating a harmful positive feedback loop. Our findings suggest that soluble MD-1 in the bloodstream triggers the production of NETs through activation of the Toll-like receptor signaling pathway and further indicate NETs mediate a crosstalk between the microenvironment of the carotid plaque and the neovascularization of the intraplaque region. Inhibiting NETs formation or MD-1 secretion may represent a promising strategy to effectively suppress the development of unstable carotid plaques.

Clinical and Angiographic Profiles of Myocardial Infarction in a Young South Indian Population

Introduction Myocardial infarction (MI) in young South Indians presents a shifting epidemiological landscape, challenging traditional perceptions of cardiovascular diseases. This study investigates the clinical and angiographic profiles of MI in this subgroup of the population in detail, emphasizing the interaction between lifestyle, environmental, and genetic factors that contribute to the incidence of MI in younger people. Methodology Utilizing a descriptive observational design, the study analyzed data from 70 young adults (aged 18-45 years) admitted to Frontier Lifeline Hospital, Chennai, with acute MI over six months. Patient demographics, clinical characteristics, and angiographic findings were collected and analyzed using standardized protocols. Statistical analysis employed chi-square tests and subgroup analyses to assess associations and differences between diabetic and non-diabetic patients. Results The study revealed a predominance of males (84.29%) among MI cases, with ST-elevation myocardial infarction (STEMI) being the most common presentation (52.86%). Anterior wall involvement was prevalent (50%), and left ventricular systolic dysfunction (LVSD) was observed in the majority (67%) of patients. Chest pain (87%) was the predominant symptom, and diabetes (47%) and hypertension (47%) were the risk variables that were most common. Angiographically, the left anterior descending artery (LAD) was often affected (51%), with single-vessel disease predominating (41.43%). Conclusion The findings underscore the significance of early detection and intervention strategies for MI in young South Indians. Gender-specific risk assessment, prompt diagnosis, and tailored treatment approaches are imperative. The high prevalence of LVSD highlights the burden of cardiac morbidity, particularly in diabetic individuals. Lifestyle modifications and weight management interventions are crucial for MI prevention. This study provides insights into the frequency and features of MI in young South Indians, emphasizing the importance of collaborative efforts for early identification and control of modifiable risk factors to mitigate the burden of coronary artery disease (CAD) in this population subset.

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.

Investigating the Correlation between Serum Amyloid A and Infarct-Related Artery Patency Prior to Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction Patients

Serum amyloid A (SAA) is a cardiovascular risk factor and may serve as a predictor of infarct-related artery (IRA) patency in patients with ST-segment elevation myocardial infarction (STEMI). We measured SAA levels in STEMI patients who underwent percutaneous coronary intervention (PCI) and investigated their association with IRA patency. According to the Thrombolysis in Myocardial Infarction (TIMI) flow grade, 363 STEMI patients undergoing PCI in our hospital were divided into an occlusion group (TIMI 0-2) and a patency group (TIMI 3). The SAA level before PCI was significantly higher in STEMI patients with IRA occluded than in those with patent ones. At a cutoff value of 36.9 mg/L, SAA had a sensitivity of 63.0% and a specificity of 90.6% (area under the ROC curve [AUC] = .833, 95% CI: .793-.873, P < .001). Multivariate logistic regression analysis showed that SAA was an independent predictor of IRA patency in STEMI patients before PCI (odds ratio [OR] = 1.041, 95% CI: 1.020-1.062, P < .001). SAA can be used as a potential predictor of IRA patency in STEMI patients before PCI.

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.

Simulation of stress in a blood vessel due to plaque sediments in coronary artery disease

Atherosclerosis is a cardiovascular disease mainly caused by plaque deposition in blood vessels. Plaque comprises components such as thrombosis, fibrin, collagen, and lipid core. It plays an essential role in inducing rupture in a blood vessel. Generally, Plaque could be described as three kinds of elastic models: cellular Plaque, hypocellular Plaque, and calcified Plaque. The present study aimed to investigate the behavior of atherosclerotic plaque rupture according to different lipid cores using Fluid-Structure Interaction (FSI). The blood vessel was also varied with different thicknesses (0.05, 0.25, and 0.5 mm). In this study, FSI simulation with a cellular plaque model with various thicknesses was investigated to obtain information on plaque rupture. Results revealed that the blood vessel with Plaque having a lipid core represents higher stresses than those without a lipid core. Blood vessels' thin thickness, like a thin cap, results in more considerable than Von Mises stress. The result also suggests that even at low fracture stress, the risk of rupture due to platelet decomposition at the gap was more significant for cellular plaques.

Atherosclerotic Plaque Erosion: Mechanisms, Clinical Implications, and Potential Therapeutic Strategies-A Review

Atherosclerosis is an insidious and progressive inflammatory disease characterized by the formation of lipid-laden plaques within the intima of arterial walls with potentially devastating consequences. While rupture of vulnerable plaques has been extensively studied, a distinct mechanism known as plaque erosion (PE) has gained recognition and attention in recent years. PE, characterized by the loss of endothelial cell lining in the presence of intact fibrous cap, contributes to a significant and growing proportion of acute coronary events. However, despite a heterogeneous substrate underlying coronary thrombosis, treatment remains identical. This article provides an overview of atherosclerotic PE characteristics and its underlying mechanisms, highlights its clinical implications, and discusses potential therapeutic strategies.

Diagnostic potential of TSH to HDL cholesterol ratio in vulnerable carotid plaque identification

Objective

This study aimed to investigate the predictive value of the thyroid-stimulating hormone to high-density lipoprotein cholesterol ratio (THR) in identifying specific vulnerable carotid artery plaques.

Methods

In this retrospective analysis, we included 76 patients with carotid plaques who met the criteria for admission to Zhejiang Hospital from July 2019 to June 2021. High-resolution magnetic resonance imaging (HRMRI) and the MRI-PlaqueView vascular plaque imaging diagnostic system were utilized to analyze carotid artery images for the identification of specific plaque components, including the lipid core (LC), fibrous cap (FC), and intraplaque hemorrhage (IPH), and recording of the area percentage of LC and IPH, as well as the thickness of FC. Patients were categorized into stable plaque and vulnerable plaque groups based on diagnostic criteria for vulnerable plaques derived from imaging. Plaques were categorized based on meeting one of the following consensus criteria for vulnerability: lipid core area over 40% of total plaque area, fibrous cap thickness less than 65 um, or the presence of intraplaque hemorrhage. Plaques meeting the above criteria were designated as the LC-associated vulnerable plaque group, the IPH-associated group, and the FC-associated group. Multivariate logistic regression was employed to analyze the factors influencing carotid vulnerable plaques and specific vulnerable plaque components. Receiver operating characteristic (ROC) curves were used to assess the predictive value of serological indices for vulnerable carotid plaques.

Results

We found that THR (OR = 1.976; 95% CI = 1.094-3.570; p = 0.024) and TSH (OR = 1.939, 95% CI = 1.122-3.350, p = 0.018) contributed to the formation of vulnerable carotid plaques. THR exhibited an area under the curve (AUC) of 0.704 (95% CI = 0.588-0.803) (p = 0.003), and the AUC for TSH was 0.681 (95% CI = 0.564-0.783) (p = 0.008). THR was identified as an independent predictor of LC-associated vulnerable plaques (OR = 2.117, 95% CI = 1.064-4.212, p = 0.033), yielding an AUC of 0.815. THR also demonstrated diagnostic efficacy for LC-associated vulnerable plaques.

Conclusion

This study substantiated that THR and TSH have predictive value for identifying vulnerable carotid plaques, with THR proving to be a more effective diagnostic indicator than TSH. THR also exhibited predictive value and specificity in the context of LC-associated vulnerable plaques. These findings suggest that THR may be a promising clinical indicator, outperforming TSH in detecting specific vulnerable carotid plaques.

Photon-Counting Computed Tomography in Atherosclerotic Plaque Characterization

Atherosclerotic plaque buildup in the coronary and carotid arteries is pivotal in the onset of acute myocardial infarctions or cerebrovascular events, leading to heightened levels of illness and death. Atherosclerosis is a complex and multistep disease, beginning with the deposition of low-density lipoproteins in the arterial intima and culminating in plaque rupture. Modern technology favors non-invasive imaging techniques to assess atherosclerotic plaque and offer insights beyond mere artery stenosis. Among these, computed tomography stands out for its widespread clinical adoption and is prized for its speed and accessibility. Nonetheless, some limitations persist. The introduction of photon-counting computed tomography (PCCT), with its multi-energy capabilities, enhanced spatial resolution, and superior soft tissue contrast with minimal electronic noise, brings significant advantages to carotid and coronary artery imaging, enabling a more comprehensive examination of atherosclerotic plaque composition. This narrative review aims to provide a comprehensive overview of the main concepts related to PCCT. Additionally, we aim to explore the existing literature on the clinical application of PCCT in assessing atherosclerotic plaque. Finally, we will examine the advantages and limitations of this recently introduced technology.

Coronary artery calcification: concepts and clinical applications

Vascular calcification is an important hallmark of atherosclerosis. Coronary artery calcification (CAC) implies the presence of coronary artery disease (CAD), irrespective of risk factors or symptoms, is concomitant with the development of advanced atherosclerosis. Coronary thrombosis is the most common clinical end event leading to acute coronary syndrome (ACS). The least common type of pathology associated with thrombosis is the calcified nodule (CN). It usually occurs in elderly patients with severely calcified and tortuous arteries. The prevalence of calcified nodules in patients with ACS may be underestimated due to the lack of easily recognisable diagnostic methods. In this review, the authors will focus on the classification, clinical significance, pathogenesis, and diagnostic evaluation and treatment of CAC to further explore the clinical significance of CN.

Comparing various AI approaches to traditional quantitative assessment of the myocardial perfusion in [82Rb] PET for MACE prediction

Assessing the individual risk of Major Adverse Cardiac Events (MACE) is of major importance as cardiovascular diseases remain the leading cause of death worldwide. Quantitative Myocardial Perfusion Imaging (MPI) parameters such as stress Myocardial Blood Flow (sMBF) or Myocardial Flow Reserve (MFR) constitutes the gold standard for prognosis assessment. We propose a systematic investigation of the value of Artificial Intelligence (AI) to leverage [82 Rb] Silicon PhotoMultiplier (SiPM) PET MPI for MACE prediction. We establish a general pipeline for AI model validation to assess and compare the performance of global (i.e. average of the entire MPI signal), regional (17 segments), radiomics and Convolutional Neural Network (CNN) models leveraging various MPI signals on a dataset of 234 patients. Results showed that all regional AI models significantly outperformed the global model ( p < 0.001 ), where the best AUC of 73.9% (CI 72.5-75.3) was obtained with a CNN model. A regional AI model based on MBF averages from 17 segments fed to a Logistic Regression (LR) constituted an excellent trade-off between model simplicity and performance, achieving an AUC of 73.4% (CI 72.3-74.7). A radiomics model based on intensity features revealed that the global average was the least important feature when compared to other aggregations of the MPI signal over the myocardium. We conclude that AI models can allow better personalized prognosis assessment for MACE.

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.

Molecular Pathways of Vulnerable Carotid Plaques at Risk of Ischemic Stroke: A Narrative Review

The concept of vulnerable carotid plaques is pivotal in understanding the pathophysiology of ischemic stroke secondary to large-artery atherosclerosis. In macroscopic evaluation, vulnerable plaques are characterized by one or more of the following features: microcalcification; neovascularization; lipid-rich necrotic cores (LRNCs); intraplaque hemorrhage (IPH); thin fibrous caps; plaque surface ulceration; huge dimensions, suggesting stenosis; and plaque rupture. Recognizing these macroscopic characteristics is crucial for estimating the risk of cerebrovascular events, also in the case of non-significant (less than 50%) stenosis. Inflammatory biomarkers, such as cytokines and adhesion molecules, lipid-related markers like oxidized low-density lipoprotein (LDL), and proteolytic enzymes capable of degrading extracellular matrix components are among the key molecules that are scrutinized for their associative roles in plaque instability. Through their quantification and evaluation, these biomarkers reveal intricate molecular cross-talk governing plaque inflammation, rupture potential, and thrombogenicity. The current evidence demonstrates that plaque vulnerability phenotypes are multiple and heterogeneous and are associated with many highly complex molecular pathways that determine the activation of an immune-mediated cascade that culminates in thromboinflammation. This narrative review provides a comprehensive analysis of the current knowledge on molecular biomarkers expressed by symptomatic carotid plaques. It explores the association of these biomarkers with the structural and compositional attributes that characterize vulnerable plaques.

Does the Location of Fat Accumulation Affect the Degree of Aortic and Renal Arterial Calcification?

The vascular risk associated with obesity is particularly associated with visceral adiposity, but recent studies suggest that ectopic fat might contribute to the increased risk of atherosclerotic cardiovascular disease. Our study aimed to explore the connection between arterial calcification of the aorta and renal arteries with visceral and ectopic fat deposits, including liver, pancreatic, and renal sinus fat. Retrospective analysis of thoracoabdominal multi-slice computed tomography (MSCT) scans of 302 patients included measurements of calcification volumes of thoracic and abdominal aorta, and of both renal arteries. On the same scans, the visceral fat volume, liver-to-spleen ratio, pancreatic-to-spleen ratio, and both renal sinus fat areas were retrieved. Logistic regression showed the left kidney sinus fat area to be the most strongly associated with calcifications in the aorta and both renal arteries (coef. from 0.578 to 0.913, p < 0.05). The visceral fat positively predicted aortic calcification (coef. = 0.462, p = 0.008), and on the contrary, the pancreatic fat accumulation even showed protective effects on thoracic and abdominal aorta calcification (coef. = -0.611 and -0.761, p < 0.001, respectively). The results suggest that ectopic fat locations differently impact the calcification of arteries, which should be further explored.

Endovascular Drug Delivery

Drug-eluting stents (DES) and balloons revolutionize atherosclerosis treatment by targeting hyperplastic tissue responses through effective local drug delivery strategies. This review examines approved and emerging endovascular devices, discussing drug release mechanisms and their impacts on arterial drug distribution. It emphasizes the crucial role of drug delivery in modern cardiovascular care and highlights how device technologies influence vascular behavior based on lesion morphology. The future holds promise for lesion-specific treatments, particularly in the superficial femoral artery, with recent CE-marked devices showing encouraging results. Exciting strategies and new patents focus on local drug delivery to prevent restenosis, shaping the future of interventional outcomes. In summary, as we navigate the ever-evolving landscape of cardiovascular intervention, it becomes increasingly evident that the future lies in tailoring treatments to the specific characteristics of each lesion. By leveraging cutting-edge technologies and harnessing the potential of localized drug delivery, we stand poised to usher in a new era of precision medicine in vascular intervention.

A Novel Artificial Coronary Plaque to Model Coronary Heart Disease

BACKGROUND

Experimental coronary artery interventions are currently being performed on non-diseased blood vessels in healthy animals. To provide a more realistic pathoanatomical scenario for investigations on novel interventional and surgical therapies, we aimed to fabricate a stenotic lesion, mimicking the morphology and structure of a human atherosclerotic plaque.

METHODS

In an interdisciplinary setting, we engineered a casting mold to create an atherosclerotic plaque with the dimensions to fit in a porcine coronary artery. Oscillatory rheology experiments took place along with long-term stability tests assessed by microscopic examination and weight monitoring. For the implantability in future in vivo setups, we performed a cytotoxicity assessment, inserted the plaque in resected pig hearts, and performed diagnostic imaging to visualize the plaque in its final position.

RESULTS

The most promising composition consists of gelatin, cholesterol, phospholipids, hydroxyapatite, and fine-grained calcium carbonate. It can be inserted in the coronary artery of human-sized pig hearts, producing a local partial stenosis and interacting like the atherosclerotic plaque by stretching and shrinking with the vessel wall and surrounding tissue.

CONCLUSION

This artificial atherosclerotic plaque model works as a simulating tool for future medical testing and could be crucial for further specified research on coronary artery disease and is going to help to provide information about the optimal interventional and surgical care of the disease.

eIF2α-mediated integrated stress response links multiple intracellular signaling pathways to reprogram vascular smooth muscle cell fate in carotid artery plaque

Background

Carotid arterial atherosclerotic stenosis is a well-recognized pathological basis of ischemic stroke; however, its underlying molecular mechanisms remain unknown. Vascular smooth muscle cells (VSMCs) play fundamental roles in the initiation and progression of atherosclerosis. Organelle dynamics have been reported to affect atherosclerosis development. However, the association between organelle dynamics and various cellular stresses in atherosclerotic progression remain ambiguous.

Methods

In this study, we conducted transcriptomics and bioinformatics analyses of stable and vulnerable carotid plaques. Primary VSMCs were isolated from carotid plaques and subjected to histopathological staining to determine their expression profiles. Endoplasmic reticulum (ER), mitochondria, and lysosome dynamics were observed in primary VSMCs and VSMC cell lines using live-cell imaging. Moreover, the mechanisms underlying disordered organelle dynamics were investigated using comprehensive biological approaches.

Results

ER whorls, a representative structural change under ER stress, are prominent dynamic reconstructions of VSMCs between vulnerable and stable plaques, followed by fragmented mitochondria and enlarged lysosomes, suggesting mitochondrial stress and lysosomal defects, respectively. Induction of mitochondrial stress alleviated ER stress and autophagy in an eukaryotic translation initiation factor (eIF)-2α-dependent manner. Furthermore, the effects of eIF2α on ER stress, mitochondrial stress, and lysosomal defects were validated using clinical samples.

Conclusion

Our results indicate that morphological and functional changes in VSMC organelles, especially in ER whorls, can be used as reliable biomarkers for atherosclerotic progression. Moreover, eIF2α plays an important role in integrating multiple stress-signaling pathways to determine the behavior and fate of VSMCs.