Plaque Characteristics Research Articles

Computed Tomography Evaluation of Coronary Atherosclerosis: The Road Travelled, and What Lies Ahead.

Coronary CT angiography (CCTA) is now endorsed by all major cardiology guidelines for the investigation of chest pain and assessment for coronary artery disease (CAD) in appropriately selected patients. CAD is a leading cause of morbidity and mortality. There is extensive literature to support CCTA diagnostic and prognostic value both for stable and acute symptoms. It enables rapid and cost-effective rule-out of CAD, and permits quantification and characterization of coronary plaque and associated significance. In this comprehensive review, we detail the road traveled as CCTA evolved to include quantitative assessment of plaque stenosis and extent, characterization of plaque characteristics including high-risk features, functional assessment including fractional flow reserve-CT (FFR-CT), and CT perfusion techniques. The state of current guideline recommendations and clinical applications are reviewed, as well as future directions in the rapidly advancing field of CT technology, including photon counting and applications of artificial intelligence (AI).

Non-alcoholic fatty liver disease: A new predictor of recurrent ischemic stroke and transient ischemic attack in patients with carotid atherosclerosis

PurposeNon-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. This study focused on assessing the predictive significance of NAFLD for recurrent stroke and transient ischemic attack (TIA) risk to determine the value of NAFLD. MethodThis study included 742 participants (mean age: 64.26 ± 9.42 years, 497 males) with carotid atherosclerosis who underwent carotid CT angiography (CTA) between January 2013 and December 2021 in this retrospective study. NAFLD was diagnosed by non-enhanced abdominal CT. The clinical endpoint was a recurrent ischemic stroke or TIA. Cox proportional hazards and Kaplan-Meier analysis assessed whether NAFLD was associated with the endpoint. We accessed the predictive values of NAFLD, clinical, plaque characteristics, and combined model by the C statistics. The predictive performance of the combined model was assessed by receiver operating characteristic curve (ROC) analysis. ResultsA total of 742 participants (mean age: 64.26 ± 9.42 years, 497 males) were included. During 2.9 years of follow-up (interquartile range, 2.1–3.9), 166 patients reached the clinical endpoint. Multivariable cox analyses showed NAFLD was associated with recurrent stroke or TIA in all groups (all P<0.05). Patients with NAFLD had a lower event-free survival (EFS) rate than those without NAFLD (P<0.05). The combined model, including NAFLD, clinical data and plaque features, showed the best performance in predicting the clinical endpoint (AUC=0.79). ConclusionsNAFLD contributes to the prediction of recurrent ischemic stroke or TIA. NAFLD may be a novel imaging marker that offers a new perspective on preventing cardiovascular disease in the clinic.

The role of advanced physiological guidance in contemporary coronary artery disease management.

This review evaluates the emerging role of the pullback pressure gradient (PPG) as a standardized metric for assessing coronary artery disease (CAD) patterns and its implications for clinical decision-making when managing patients undergoing percutaneous coronary interventions (PCIs). By integrating PPG with existing physiological assessments, this review highlights the potential benefits of PPG in predicting treatment outcomes and refining therapeutic strategies for CAD. Recent studies, particularly the PPG Global study have demonstrated a strong correlation between PPG values and post-PCI outcomes, revealing that focal disease is associated with improved fractional flow reserve (FFR) and lower rates of adverse events than vessels with diffuse disease (low PPG). Additionally, PPG has been linked to specific atherosclerotic plaque characteristics, indicating its utility in identifying high-risk plaques. The integration of PPG with advanced imaging techniques further enhances the understanding of CAD patterns and their implications for treatment planning. The PPG represents a significant advancement in the management of CAD, providing a reproducible and objective assessment of coronary artery disease patterns that can inform clinical decision-making. As research continues to explore the relationship among PPG, atherosclerotic characteristics, and patient outcomes, its integration into routine practice is expected to improve the effectiveness of PCI and optimize patient management strategies. Future studies are warranted to establish specific PPG thresholds and further investigate its potential in identifying vulnerable plaques and guiding treatment decisions.

Association between elevated lipoprotein(a) levels and vulnerability of carotid atherosclerotic plaque: A systematic review

BackgroundThe role of lipoprotein(a) [Lp(a)] as a potential risk factor for atherosclerotic arterial disease has been extensively studied. However, the available data regarding its association with the vulnerability of carotid atherosclerotic plaque is limited. The main objective of the present systematic review was to assess the association between elevated Lp(a) levels and carotid vulnerable plaque features. MethodsThis systematic review adhered to PRISMA guidelines, conducting a comprehensive literature search to identify studies examining the association between Lp(a) levels and vulnerability of carotid atherosclerotic plaque. Experimental or observational studies were eligible, without language, country, or publication type restrictions. ResultsNine studies including 2058 patients were eligible for this systematic review. Five cross-sectional studies, 3 prospective/retrospective cohorts, and 1 subanalysis of a randomized controlled trial were analyzed. Two cross-sectional studies that compared Lp(a) levels between patients with and without vulnerable carotid plaque showed discordant results. Nevertheless, all the studies that evaluated the prevalence or incidence of vulnerable carotid plaque according to Lp(a) levels showed a positive association. Similarly, one study found a significant correlation between vulnerability of carotid plaque and Lp(a) levels. ConclusionAlmost all studies analyzed in the present review showed a positive association between elevated Lp(a) levels and carotid vulnerable plaque features. However, further research is needed to clarify this issue.

Risk factors for hypoechoic carotid plaque in healthy physical-examination population

BackgroundWe studied the characteristics of carotid ultrasound plaque in a healthy physical-examination population and analyzed the risk factors for hypoechoic carotid plaque for early control and prevention of stroke.ResultsA total of 1333 healthy physical-examination individuals were included in this study, including 457 females and 876 males. According to the results of carotid artery ultrasound, they were divided into hyperechoic carotid plaque (n = 940) and hypoechoic carotid plaque (n = 393). Multivariate logistic analysis showed that male, alcohol consumption, and low-density lipoprotein were risk factors for hypoechoic carotid plaque. SPSS 25.0 software was used to draw the receive operating characteristic curve and calculate the prediction probability of the risk factor indicators obtained by the multifactor model. The area under the curve was also calculated to be 0.623 (95% CI = 0.591–0.655).ConclusionMale, alcohol consumption, and low-density lipoprotein are risk factors for hypoechoic carotid plaque in a healthy physical-examination population.

Automated diagnosis of atherosclerosis using multi-layer ensemble models and bio-inspired optimization in intravascular ultrasound imaging.

Atherosclerosis causes heart disease by forming plaques in arterial walls. IVUS imaging provides a high-resolution cross-sectional view of coronary arteries and plaque morphology. Healthcare professionals diagnose and quantify atherosclerosis physically or using VH-IVUS software. Since manual or VH-IVUS software-based diagnosis is time-consuming, automated plaque characterization tools are essential for accurate atherosclerosis detection and classification. Recently, deep learning (DL) and computer vision (CV) approaches are promising tools for automatically classifying plaques on IVUS images. With this motivation, this manuscript proposes an automated atherosclerotic plaque classification method using a hybrid Ant Lion Optimizer with Deep Learning (AAPC-HALODL) technique on IVUS images. The AAPC-HALODL technique uses the faster regional convolutional neural network (Faster RCNN)-based segmentation approach to identify diseased regions in the IVUS images. Next, the ShuffleNet-v2 model generates a useful set of feature vectors from the segmented IVUS images, and its hyperparameters can be optimally selected by using the HALO technique. Finally, an average ensemble classification process comprising a stacked autoencoder (SAE) and deep extreme learning machine (DELM) model can be utilized. The MICCAI Challenge 2011 dataset was used for AAPC-HALODL simulation analysis. A detailed comparative study showed that the AAPC-HALODL approach outperformed other DL models with a maximum accuracy of 98.33%, precision of 97.87%, sensitivity of 98.33%, and F score of 98.10%.

Influence of metabolic syndrome on plaque features and clinical outcomes in patients with acute coronary syndrome

Influence of metabolic syndrome on plaque features and clinical outcomes in patients with acute coronary syndrome

High-Risk Plaque Features in the Non-stenosing Carotid Artery, How Frequently is This Reported? A Retrospective Study

High-Risk Plaque Features in the Non-stenosing Carotid Artery, How Frequently is This Reported? A Retrospective Study

Improved Cascade-RCNN for automatic detection of coronary artery plaque in multi-angle fusion CPR images

Coronary heart disease is a disease that seriously endangers human health and life which is caused by plaque formation due to coronary artery atherosclerosis or spasm. The detection of coronary plaques through medical imaging is a non-destructive and fast diagnostic method, which holds significant medical and clinical value for the diagnosis of coronary heart disease. In this paper, We proposed an automatic detecting method for coronary artery vulnerable plaque based on CTA image sequence. We collected CTA image sequences from 132 patients and obtained the coronary artery tree by performing three-dimensional (3D) segmentation. The coronary artery centerline was extracted using the skeleton thinning method. To address the issue of insufficient features in a single CPR image, we constructed Curved Planar Reconstructed (CPR) images from multiple directions perpendicular to the coronary artery, following the centerline. In total, we established 8797 images in the training dataset and 1553 images in the test dataset. We proposed an attentive detection method that fused a new Cascade RCNN ResNet50-FPN neural network model with a convolutional attention module (CBAM). This method achieved automatic recognition and detection of plaques on the two-dimensional multi-angle fused CPR images. The proposed ResNet50-FPN network performed feature extraction, and CBAM was added after the first and last convolutional layers to enhance the network’s attention to plaque features. Our experimental results demonstrate that deep learning neural networks can provide a feasible approach to automatically detecting coronary artery plaques. Our method achieved a plaque detection accuracy of 94.6%, outperforming the RCNN method proposed by Zriek.

Predictors for Vulnerable Plaque in Functionally Significant Lesions

BackgroundVulnerable plaque presents prognostic implications in addition to functional significance. ObjectivesThe aim of this study was to identify relevant features of vulnerable plaque in functionally significant lesions. MethodsIn this multicenter, prospective study conducted across 5 countries, including patients who had invasive fractional flow reserve (FFR) ≤0.80, a total of 95 patients with available pullback pressure gradient (PPG) and plaque analysis on coronary computed tomographic angiography and optical coherence tomography were analyzed. Vulnerable plaque was defined as the presence of plaque rupture or thin-cap fibroatheroma on optical coherence tomography. Among the 25 clinical characteristics, invasive angiographic findings, physiological indexes, and coronary computed tomographic angiographic findings, significant predictors of vulnerable plaque were identified. ResultsMean percentage diameter stenosis, FFR, and PPG were 77.8% ± 14.6%, 0.66 ± 0.13, and 0.65 ± 0.13, respectively. Vulnerable plaque was present in 53 lesions (55.8%). PPG and FFR were identified as significant predictors of vulnerable plaque (P < 0.05 for all). PPG >0.65 and FFR ≤0.70 were significantly related to a higher probability of vulnerable plaque after adjustment for each other (OR: 6.75 [95% CI: 2.39-19.1]; P < 0.001] for PPG >0.65; OR: 4.61 [95% CI: 1.66-12.8]; P = 0.003 for FFR ≤0.70). When categorizing lesions according to combined PPG >0.65 and FFR ≤0.70, the prevalence of vulnerable plaque was 20.0%, 57.1%, 66.7%, and 88.2% in the order of PPG ≤0.65 and FFR >0.70, PPG ≤0.65 and FFR ≤0.70, PPG >0.65 and FFR >0.70, and PPG >0.65 and FFR ≤0.70 (P for trend < 0.001), respectively. ConclusionsAmong low-FFR lesions, the presence of vulnerable plaque can be predicted by PPG combined with FFR without additional anatomical or plaque characteristics. (Precise Percutaneous Coronary Intervention Plan [P3] Study; NCT03782688)

Evaluation of Pericoronary Fat Attenuation Index to Better Identify Culprit Lesions in Acute Coronary Syndrome According to Stenosis Severity.

To investigate the incremental value of pericoronary fat attenuation index (FAI) in routine coronary artery computed tomography angiography (CCTA) to identify culprit lesions in acute coronary syndrome (ACS). We reviewed the CCTA data from 80 ACS patients and 40 individuals with stable coronary atherosclerosis. ACS patient plaques were categorized into culprit and nonculprit groups. The plaque-specific pericoronary FAI was assessed using the Perivascular Fat Analysis Tool. We applied a default prespecified window of -190 to -30 Hounsfield units (HU) and a broader prespecified window of -190 to 20 HU. FAI values within these prespecified windows and the types and severity of plaque stenosis were compared across the 3 groups. Additionally, we investigated high-risk characteristics of plaques in the ACS group and their correlation with FAI. The effectiveness and worthiness of FAI in identifying culprit lesions were analyzed based on the receiver operating characteristic curve. The FAI values under the 2 prespecified windows were higher in the culprit group than in the nonculprit and control groups (all P < 0.001). The culprit group showed the most mixed plaques and the most severe stenosis (all P < 0.001). In the ACS group, the FAI value was significantly lower around calcified lesions (-85.00 ± 9.97 HU) than around noncalcified (-78.00 ± 11.52 HU) and mixed plaques (-78.00 ± 9.24 HU) (both P < 0.001). The culprit group had more high-risk plaques, and high-risk plaques had higher FAI values than those without high-risk characteristics (-70.00 ± 7.67 HU vs -82.00 ± 10.16 HU, P < 0.001). The efficacy of FAI under the default prespecified window in identifying culprit lesions was higher compared than that under the broader prespecified window (area under the curve = 0.799 vs 0.761, P = 0.042), and the diagnostic cutoff values were -77 versus -58 HU. The FAI under the default prespecified window exhibited an incremental value for identifying culprit lesions, as compared with stenosis severity (area under the curve = 0.970 vs 0.939, P < 0.001). The culprit lesions have higher FAI than the nonculprit lesions and the controls. FAI is a worthy parameter for identifying culprit lesions in routine CCTA according to stenosis severity, and the default prespecified window is a better option.

Comparative Prognostic Value of Coronary Calcium Score and Perivascular Fat Attenuation Index in Coronary Artery Disease.

Coronary artery disease (CAD) is the leading global cause of mortality, accounting for approximately 30% of all deaths. It is primarily characterized by the accumulation of atherosclerotic plaques within the coronary arteries, leading to reduced blood flow to the heart muscle. Early detection of atherosclerotic plaques is crucial to prevent major adverse cardiac events. Notably, recent studies have shown that 15% of myocardial infarctions occur in patients with non-obstructive CAD, underscoring the importance of comprehensive plaque assessment beyond merely identifying obstructive lesions. Cardiac Computed Tomography Angiography (CCTA) has emerged as a cost-effective and efficient technique for excluding obstructive CAD, particularly in patients with a low-to-intermediate clinical likelihood of the disease. Recent advancements in CCTA technology, such as improved resolution and reduced scan times, have mitigated many technical challenges, allowing for precise quantification and characterization of both calcified and non-calcified atherosclerotic plaques. This review focuses on two critical physiological aspects of atherosclerotic plaques: the burden of calcifications, assessed via the coronary artery calcium score (CACs), and perivascular fat attenuation index (pFAI), an emerging marker of vascular inflammation. The CACs, obtained through non-contrast CT scans, quantifies calcified plaque burden and is widely used to stratify cardiovascular risk, particularly in asymptomatic patients. Despite its prognostic value, the CACs does not provide information on non-calcified plaques or inflammatory status. In contrast, the pFAI, derived from CCTA, serves as an indirect marker of coronary inflammation and has shown potential in predicting adverse cardiac events. Combining both CACs and pFAI assessment could offer a comprehensive risk stratification approach, integrating the established calcification burden with novel inflammatory markers to enhance CAD prevention and management strategies.

Lesion-Level Effects of LDL-C–Lowering Therapy in Patients With Acute Myocardial Infarction

Previous studies investigated atherosclerotic changes induced by lipid-lowering therapy in extensive coronary segments irrespective of baseline disease burden (a vessel-level approach). To investigate the effects of lipid-lowering therapy on coronary lesions with advanced atherosclerotic plaque features and presumably higher risk for future events. The PACMAN-AMI randomized clinical trial (enrollment: May 2017 to October 2020; final follow-up: October 2021) randomized patients with acute myocardial infarction to receive alirocumab or placebo in addition to high-intensity statin therapy. In this post hoc lesion-level analysis, nonculprit lesions were identified as segments with plaque burden 40% or greater defined by intravascular ultrasound (IVUS). IVUS, near-infrared spectroscopy, and optical coherence tomography images at baseline and the 52-week follow-up were manually matched by readers blinded to treatment allocation. Data for this study were analyzed from October 2022 to November 2023. Alirocumab or placebo in addition to high-intensity statin therapy. Lesion-level imaging outcome measures, including high-risk plaque characteristics and phenotypes. Of the 245 patients in whom lesions were found, 118 were in the alirocumab group (mean [SD] age, 58.2 [10.0] years; 101 [85.6%] male and 17 [14.4%] female) and 127 in the placebo group (mean [SD] age, 57.7 [8.8] years; 104 [81.9%] male and 23 [18.1%] female). Overall, 591 lesions were included: 287 lesions (118 patients, 214 vessels) in the alirocumab group and 304 lesions (127 patients, 239 vessels) in the placebo group. Lesion-level mean change in percent atheroma volume (PAV) was -4.86% with alirocumab vs -2.78% with placebo (difference, -2.02; 95% CI, -3.00 to -1.05; P < .001). At the minimum lumen area (MLA) site, mean change in PAV was -10.14% with alirocumab vs -6.70% with placebo (difference, -3.36; 95% CI, -4.98 to -1.75; P < .001). MLA increased by 0.15 mm2 with alirocumab and decreased by 0.07 mm2 with placebo (difference, 0.21; 95% CI, 0.01 to 0.41; P = .04). Among 122 lipid-rich lesions, 34 of 55 (61.8%) in the alirocumab arm and 27 of 67 (41.8%) in the placebo arm showed a less lipid-rich plaque phenotype at follow-up (P = .03). Among 63 lesions with thin-cap fibroatheroma at baseline, 8 of 26 (30.8%) in the alirocumab arm and 3 of 37 (8.1%) in the placebo arm showed a fibrous/fibrocalcific plaque phenotype at follow-up (P = .02). At the lesion level, very intensive lipid-lowering therapy induced substantially greater PAV regression than described in previous vessel-level analyses. Compared with statin therapy alone, alirocumab treatment was associated with greater enlargement of the lesion MLA and more frequent transition of presumably high-risk plaque phenotypes into more stable, less lipid-rich plaque phenotypes. ClinicalTrials.gov Identifier: NCT03067844.

Spatial lipidomic profiles of atherosclerotic plaques: A mass spectrometry imaging study

Lipids contribute to atherosclerotic cardiovascular disease but their roles are not fully understood. Spatial lipid composition of atherosclerotic plaques was compared between species focusing on aortic plaques from New Zealand White rabbits and carotid plaques from humans (n = 3), using matrix-assisted laser desorption/ionization mass spectrometry imaging. Histologically discriminant lipids within plaque features (neointima and media in rabbits, and lipid-necrotic core and fibrous cap/tissue in humans) included sphingomyelins, phosphatidylcholines, and cholesteryl esters. There were 67 differential lipids between rabbit plaque features and 199 differential lipids in human, each with variable importance in projection score ≥1.0 and p < 0.05. The lipid profile of plaques in the rabbit model closely mimicked that of human plaques and two key pathways (impact value ≥ 0.1), sphingolipid and glycerophospholipid metabolism, were disrupted by atherosclerosis in both species. Thus, mass spectrometry imaging of spatial biomarkers offers valuable insights into atherosclerosis.

A Comprehensive Review of Cardiovascular Disease Management: Cardiac Biomarkers, Imaging Modalities, Pharmacotherapy, Surgical Interventions, and Herbal Remedies.

Cardiovascular diseases (CVDs) continue to be a major global health concern, representing a leading cause of morbidity and mortality. This review provides a comprehensive examination of CVDs, encompassing their pathophysiology, diagnostic biomarkers, advanced imaging techniques, pharmacological treatments, surgical interventions, and the emerging role of herbal remedies. The review covers various cardiovascular conditions such as coronary artery disease, atherosclerosis, peripheral artery disease, deep vein thrombosis, pulmonary embolism, cardiomyopathy, rheumatic heart disease, hypertension, ischemic heart disease, heart failure, cerebrovascular diseases, and congenital heart defects. The review presents a wide range of cardiac biomarkers such as troponins, C-reactive protein, CKMB, BNP, NT-proBNP, galectin, adiponectin, IL-6, TNF-α, miRNAs, and oxylipins. Advanced molecular imaging techniques, including chest X-ray, ECG, ultrasound, CT, SPECT, PET, and MRI, have significantly enhanced our ability to visualize myocardial perfusion, plaque characterization, and cardiac function. Various synthetic drugs including statins, ACE inhibitors, ARBs, β-blockers, calcium channel blockers, antihypertensives, anticoagulants, and antiarrhythmics are fundamental in managing CVDs. Nonetheless, their side effects such as hepatic dysfunction, renal impairment, and bleeding risks necessitate careful monitoring and personalized treatment strategies. In addition to conventional therapies, herbal remedies have garnered attention for their potential cardiovascular benefits. Plant extracts and their bioactive compounds, such as flavonoids, phenolic acids, saponins, and alkaloids, offer promising cardioprotective effects and enhanced cardiovascular health. This review underscores the value of combining traditional and modern therapeutic approaches to improve cardiovascular outcomes. This review serves as a vital resource for researchers by integrating a broad spectrum of information on CVDs, diagnostic tools, imaging techniques, pharmacological treatments and their side effects, and the potential of herbal remedies.

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

IntroductionPatients with acute coronary syndrome (ACS) have high event rates related to non-culprit (NC) lesions, therefore plaque composition of these lesions is of great interest. Although marginal atherosclerotic lesions were studied extensively, more significant lesions might have more high-risk characteristics. AimTo compare differences in high-risk lesion characteristics between significant versus non-stenotic NC plaques in ACS and the discrepancies with chronic coronary syndrome (CCS) patients. MethodsNon-culprit vessels of 26 ACS patients with 26 angiographically significant lesions and 37 patients (17 ACS and 20 CCS) with 48 non-stenotic lesions were investigated with intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS). Overall, 74 segments of 30 mm length were analyzed in 1 mm intervals. External elastic lamina (EEM), plaque burden (PB), minimal luminal area (MLA), percent atheroma volume (PAV) and lipid core burden index maximum 4 mm (maxLCBI4mm) were determined for each segment. ResultsCardiovascular risk factors were similar in all groups. PB was higher and MLA smaller in significant non-culprit ACS lesions vs non-stenotic lesions: PB 73.5% (IQR 68.7–78.5) vs 59.2 (IQR 49.6–71.5), p = 0.003, MLA 3.0 mm2 (IQR 2.3–3.9) vs 4.0 mm2 (IQR 2.8–4.7). MaxLCBI4mm was similar 308.1 (±155.4) vs 287.8 (±165.7), p = 0.67.Among non-stenotic plaques, MaxLCBI4mm was comparable between ACS and CCS patients, 275.7 (±151.5) in CCS patients vs 287.8 (±165.7) in ACS patients, p = 0.79. ConclusionAlthough visually significant non-culprit lesions had a higher plaque burden compared to non-stenotic lesions, a significant relation between MaxLCBI4mm and hemodynamic significance of the plaques couldn’t be established.

Characterization of carotid plaques using chemical exchange saturation transfer imaging.

The preoperative assessment of carotid plaques is necessary to render revascularization safe and effective. The aim of this study is to evaluate the usefulness of chemical exchange saturation transfer (CEST)-MRI, particularly amide proton transfer (APT) imaging as a preoperative carotid plaque diagnostic tool. We recorded the APT signal intensity on concentration maps of 34 patients scheduled for carotid endarterectomy. Plaques were categorized into group A (APT signal intensity ≥ 1.90 E-04; n = 12) and group B (APT signal intensity < 1.90 E-04; n = 22). Excised plaques were subjected to histopathological assessment and, using the classification promulgated by the American Heart Association, they were classified as intraplaque hemorrhage-positive [type VI-positive (tVI+)] and -negative [no intraplaque hemorrhage (tVI-)]. Of the 34 patients, 22 (64.7%) harbored tVI+- and 12 (35.3%) had tVI- plaques. The median APT signals were significantly higher in tVI+- than tIVI- patients (2.43 E-04 (IQR = 0.98-4.00 E-04) vs 0.54 E-04 (IQR = 0.14-1.09 E-04), p < .001). Histopathologically, the number of patients with tVI+ plaques was significantly greater in group A (100%, n = 12) than group B (45%, n = 22) (p < .01). The number of symptomatic patients or asymptomatic patients with worsening stenosis was also significantly greater in group A than group B (75% vs 36%, p < .01). In unstable plaques with intraplaque hemorrhage and in patients with symptoms or progressive stenosis, the ATP signals were significantly elevated. CEST-MRI studies has the potential for the preoperative assessment of the plaques' characteristics.

7T-high resolution MRI-derived radiomic analysis for the identification of symptomatic intracranial atherosclerotic plaques.

High-resolution magnetic resonance imaging (HR-MRI) allows for detailed visualization of intracranial atherosclerotic plaques. Radiomics can be used as a tool for objective quantification of the plaque's characteristics. We analyzed the radiomics features (RFs) obtained from 7 T HR-MRI of patients with intracranial atherosclerotic disease (ICAD) to determine distinct characteristics of culprit and non-culprit plaques. Patients with stroke due to ICAD underwent HR-MRI. Culprit plaques in the vascular territory of the stroke were identified. Degree of stenosis, area degree of stenosis and plaque burden were calculated. A three-dimensional segmentation of the plaque was performed, and RFs were obtained. A machine learning model for prediction and identification of culprit plaques using significantly different RFs was evaluated. The study included 33 patients with ICAD as stroke etiology. Univariate analysis revealed 24 RFs in pre-contrast MRI, 21 in post-contrast MRI, 13 RFs that were different between pre and post contrast MRIs. Additionally, six shape-based RFs significantly differed from culprit and non-culprit plaques. The random forest model achieved an accuracy rate of 81% (88% sensitivity and 75% specificity) in identifying culprit plaques in the independent testing dataset. This model successfully identified the culprit plaques in all patients during the testing phase. Symptomatic plaques had a distinct signature RFs compared to other plaques within the same subject. A machine learning model built with RFs successfully identified the symptomatic atherosclerotic plaques in most cases. Radiomics is a promising tool for stratification of plaques in patients with ICAD.

Intravascular ICG-enhanced NIRF-IVUS imaging to assess progressive atherosclerotic lesions in excised human coronary arteries

Indocyanine green (ICG)-enhanced intravascular near-infrared fluorescence (NIRF) imaging enhances the information obtained with intravascular ultrasound (IVUS) by visualizing pathobiological characteristics of atherosclerotic plaques. To advance our understanding of this hybrid method, we aimed to assess the potential of NIRF-IVUS to identify different stages of atheroma progression by characterizing ICG uptake in human pathological specimens. After excision, 15 human coronary specimens from 13 adult patients were ICG-perfused and imaged with NIRF-IVUS. All specimens were then histopathologically and immunohistochemically assessed. NIRF-IVUS imaging revealed colocalization of ICG-deposition to plaque areas of lipid accumulation, endothelial disruption, neovascularization and inflammation. Moreover, ICG concentrations were significantly higher in advanced coronary artery disease stages (p < 0.05) and correlated significantly to plaque macrophage burden (r = 0.67). Current intravascular methods fail to detect plaque biology. Thus, we demonstrate how human coronary atheroma stage can be assessed based on pathobiological characteristics uniquely captured by ICG-enhanced intravascular NIRF.

Age-specific sex differences in intravascular ultrasound based coronary atherosclerotic plaque characteristics

Insights in age- and sex-specific coronary atherosclerotic plaque characteristics may contribute to a better understanding of coronary artery disease and, ultimately, to its prevention and treatment. In 307 women and 406 men aged 20 to 90 years undergoing intravascular ultrasound imaging, sex-based differences in coronary atherosclerotic plaque characteristics were mainly present in younger patients, while these differences were less pronounced at advanced age.