Prevalence of High-risk Plaques and Risk of Stroke in Patients With Asymptomatic Carotid Stenosis: A Meta-analysis

Treat the patient, not the disease: The embolic stroke of undetermined source as an opportunity to optimize cardiovascular prevention in a holistic approach

For any physician treating a patient with a medical condition of unclear etiology, the differential diagnosis aims to identify the actual most probable cause among various potential etiologies, in order to tailor treatment options. In patients with embolic stroke of undetermined source (ESUS), this can be challenging due to the frequent presence of multiple potential embolic sources, raising difficulties to identify the most likely cause. Additionally, despite targeted preventive measures for the presumed embolic source, patients may remain at risk for stroke and cardiovascular events due to other unrecognized or underestimated pathologies. The multi-level complexity and multimorbidity typically associated with ESUS, represents a challenge that requires broad knowledge of the cardiovascular pathophysiology, deep expertise of the available diagnostic and therapeutic options, and interdisciplinary approach. At the same time, it is an ideal opportunity to assess thoroughly the overall cardiovascular status of the patient, which in turn can allow us to optimize therapeutic and preventive strategies in a holistic approach, and prevent future strokes, cardiovascular events and disability through different parallel pathways. In this context, rather than narrowing our perspective on identifying the specific embolic source presumed to be the most likely cause of ESUS, it is crucial to shift our focus from the disease to the patient, and evaluate the overall cardiovascular profile by assessing the risk of all cardiovascular comorbidities present, no matter if causally associated with ESUS or not. In order to bring across these points and more, this article is centred around a clinical case that serves as a starting point to illustrate the holistic approach to the management of patients with ESUS. After all, this is the beauty, the magic and the art of Internal Medicine: to treat the patient, not the disease, the system or the organ.

Best Medical Therapy for Asymptomatic Carotid Stenosis: Imminent or Ineffective?

Carotid artery disease accounts for approximately 20% of all ischemic strokes, a major cause of morbidity, and the fifth leading cause of death in the United States. Landmark trials in the 1990s, such as Asymptomatic Carotid Atherosclerosis Study and Asymptomatic Carotid Surgery Trial, establish carotid endarterectomy (CEA) plus best medical therapy (BMT) as the standard of care for patients with asymptomatic carotid stenosis over 60%. However, advances in medical therapy and the emergence of carotid artery stenting (CAS) have prompted a reevaluation of treatment efficacy. Recent studies have questioned the superiority of CEA over BMT alone in reducing stroke risk, suggesting no significant difference in outcomes with contemporary medical management. In addition, analysis from the U. S. Department of Veterans Affairs indicated minimal net benefit of CEA over BMT when accounting for all-cause mortality. Comparative studies have found no significant difference in long-term stroke-free survival between CEA and CAS. However, procedural risks vary, with higher myocardial infarction rates associated with CEA and higher stroke rates with CAS. Identifying high-risk plaques and patient-specific risk factors remains crucial. Meta-analyses have highlighted features such as neovascularization and lipid rich cores as predictors of stenosis progression and ischemic events. Ongoing research, particularly the CREST-2 trial, aims to provide clear guidance on the optimal treatment of asymptomatic carotid stenosis. This trial emphasizes stringent adherence to modern BMT protocols and includes comprehensive lifestyle modification programs. The evolving landscape of medical and surgical interventions necessitates continuous evaluation to optimize treatment strategies for asymptomatic carotid stenosis, which is the impetus for this review. Future findings from ongoing trials are expected to refine current guidelines and improve patient outcomes.

Asymptomatic Carotid Artery Stenosis, Cognitive Function, and the Impact of Carotid Revascularization: A Narrative Review

BACKGROUND

The association between asymptomatic carotid artery stenosis and impaired cognition, and the cognitive changes after revascularization remain active areas of interest in the field of carotid disease. This narrative review focuses on the association between carotid artery atherosclerosis and impaired cognitive function, proposed mechanisms, and the effects of carotid revascularization on cognition.

METHODS

A critical review of the literature to identify studies evaluating carotid artery stenosis, cognition, and carotid revascularization was performed using PubMed to query the MEDLINE database through March 2023.

RESULTS

Many studies demonstrate a link between carotid disease and cognitive impairment but direct evidence is lacking. Revascularization may offer cognitive benefits but the effect is likely subtle and affected by the choice of revascularization procedure.

CONCLUSIONS

Integrating cognitive outcomes into ongoing randomized controlled trials such as the nested CREST-H arm of the CREST-2 trial hold promise for offering new insight into the role of carotid artery stenosis and carotid revascularization on cognition.

Retrospective Analysis of a Novel Grading System for Evaluating the Long-Term Benefit of Revascularization on Carotid Artery Stenosis

BACKGROUND

To estimate revascularization benefit for carotid artery stenosis, with a novel grading system containing symptoms, stenosis, plaque, and collateral compensation (SSPC grading system).

METHODS

A retrospective multicenter study examined 945 consecutive patients diagnosed with carotid stenosis from January 2013 to December 2017. The cohort was classified into 2 groups: the revascularization group and the best medical therapy (BMT) group. Demographic, clinical, and lesion characteristics of all patients were recorded and 5-year nonprocedural stroke survival was calculated using Kaplan-Meier curve analyses.

RESULTS

Of the 945 patients, 514 underwent carotid revascularization (483 for carotid endarterectomy and 31 for transfemoral-carotid artery stenting) and 431 patients were treated with BMT. Patients in the revascularization group had a significantly higher proportion of preprocedural stroke/transient ischemic attack (TIA) and grades of stenosis. Of the patients in the revascularization group, 3.1% were classified as SSPC I, 10.3% as SSPC II, 41.4% as SSPC III, and 45.1% as SSPC IV. Meanwhile, 17.9% were classified as SSPC I, 19.7% as SSPC II, 49.2% as class III, and 13.2% had class IV in the BMT group. Procedural stroke developed in 13 patients (2.5%) following revascularization (10 of them were non-disabling). The overall rate of freedom from any nonprocedural stroke was 94.1 ± 1.1% in the revascularization group and 89.5 ± 1.6% in the BMT group (P = 0.01). Subgroup analysis was conducted for asymptomatic carotid stenosis (ACS) and carotid near-occlusion (CNO) patients. Nonsignificance was noted in the rate of freedom from any nonprocedural stroke between revascularization and BMT in both ACS and CNO subgroups (P = 0.09 and 0.12, respectively). Of note, in ACS patients graded as SSPC III, a significant difference in stroke survival was found between the revascularization and BMT group (96.0 ± 2.0% vs. 89.1 ± 2.4%, P = 0.04). Meanwhile, in symptomatic CNO patients, similar results were found regarding SSPC classification (94.8 ± 3.6% vs. 63.8 ± 14.9%, P = 0.01).

CONCLUSIONS

The SSPC grading system stratifies the patients with carotid artery stenosis and predicts the long-term benefits of revascularization. Meanwhile, potential revascularization benefits could be better attained via SSPC classes in specific patients with ACS and CNO.

A cross-sectional study comparing the expression of DNA repair molecules in subjects with and without atherosclerotic plaques

BACKGROUND

Atherosclerosis, serving as the primary pathological mechanism at the core of cardiovascular disease, is now widely acknowledged to be associated with DNA damage and repair, contributing to atherosclerotic plaque formation. Therefore, molecules involved in the DNA repair process may play an important role in the progression of atherosclerosis. Our research endeavors to explore the contributions of specific and interrelated molecules involved in DNA repair (APE1, BRCA1, ERCC2, miR-221-3p, miR-145-5p, and miR-155-5p) to the development of atherosclerotic plaque and their interactions with each other.

METHODS & RESULTS

Gene expression study was conducted using the real-time polymerase chain reaction (qRT-PCR) method on samples from carotid artery atherosclerotic plaques and nonatherosclerotic internal mammary arteries obtained from 50 patients diagnosed with coronary artery disease and carotid artery disease. Additionally, 50 healthy controls were included for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Although no difference was observed in mRNA gene expressions, we noted a decrease in miR-155-5p gene expression (p = 0.003) and an increase in miR-221-3p gene expression (p = 0.015) in plaque samples, while miR-145-5p gene expression remained unchanged (p = 0.57). Regarding serum 8-OHdG levels, patients exhibited significantly higher levels (1111.82 ± 28.64) compared to controls (636.23 ± 24.23) (p < 0.0001).

CONCLUSIONS

In our study demonstrating the role of miR-155-5p and miR-221-3p in atherosclerosis, we propose that these molecules are potential biomarkers and therapeutic targets for coronary artery diseases and carotid artery disease.

Diagnostics Accuracy of Magnetic Resonance Imaging in Detection of Atherosclerotic Plaque Characteristics in Carotid Arteries Compared to Histology: A Systematic Review

Carotid plaque composition represents one of the main risk factors of future ischemic stroke. MRI provides excellent soft tissue contrast that can distinguish plaque characteristics. Our objective was to analyze the diagnostic accuracy of MRI imaging in the detection of carotid plaque characteristics compared to histology in patients with symptomatic and asymptomatic carotid atherosclerosis through a systematic review. After prospective registration in PROSPERO (ID CRD42022329690), Medline Ovid, Embase.com, Cochrane Library, and Web of Science Core were searched without any search limitation up to May 27, 2022 to identify eligible articles. Of the 8168 studies, 53 (37 × 1.5 T MRI, 17 × 3 T MRI) evaluated MRI accuracy in the detection of 13 specific carotid plaque characteristics in 169 comparisons. MRI demonstrated high diagnostic accuracy for detection of calcification (3 T MRI: mean sensitivity 92%/mean specificity 90%; 1.5 T MRI: mean sensitivity 81%/mean specificity 91%), fibrous cap (1.5 T: 89%/87%), unstable plaque (1.5 T: 89%/87%), intraplaque hemorrhage (1.5 T: 86%/88%), and lipid-rich necrotic core (1.5 T: 89%/79%). MRI also proved to have a high level of tissue discrimination for the carotid plaque characteristics investigated, allowing potentially for a better risk assessment and follow-up of patients who may benefit from more aggressive treatments. These results emphasize the role of MRI as the first-line imaging modality for comprehensive assessment of carotid plaque morphology, particularly for unstable plaque. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Association Between Calculated Small Dense Low-Density Lipoprotein Cholesterol (sdLDL-C) and Soft Carotid Plaques on CT Angiogram of the Head and Neck

BACKGROUND

Cerebrovascular accident (CVA), also commonly known as stroke, is an acute condition characterized by jeopardized perfusion of the brain tissue. Atherosclerosis is a common converging point for the various risk factors for CVA. It is a chronic, evolving condition of the vessel wall characterized by peculiar lesions known as atheromas. Low-density lipoprotein cholesterol (LDL-C) has been one of the established and traditional risk factors for the development of plaques in atherosclerosis. Small dense LDL-C (sdLDL-C) is a subclass of LDL-C that is considered more atherogenic, and its role in atherosclerotic plaque formation has been very well established. Hence, in this study, we aimed to find the association between calculated sdLDL-C and atherosclerotic carotid plaque (including various plaque characteristics).

MATERIALS AND METHODS

This retrospective cross-sectional study was conducted at Sri Ramachandra Medical College and Research Institute between December 2022 and December 2023 after getting ethics approval from the Institutional Ethics Committee. Patients who underwent CT angiogram (312) were included in the study, and their lipid profile data were collected from the Laboratory Information System. Participants were divided into groups depending on the presence or absence of carotid plaque, the characteristics of the plaque, and the narrowing caused by the plaque. sdLDL-C was calculated using Sampson formula from the lipid parameters in these groups. Statistical analysis was done using SPSS Statistics version 16.0 (SPSS Inc. Released 2007. SPSS for Windows, Version 16.0. Chicago, SPSS Inc.). A p-value of <0.05 was considered significant.

RESULTS

sdLDL-C was significantly higher in the plaque group (37.25 ± 13.69 mg/dL) when compared to the group without plaques on CT angiogram (34.09 ± 11.64 mg/dL) (p<0.05), wherein the LDL-C wasn't significantly different between the two groups. sdLDL-C was also elevated in the soft plaque sub-group (39.46 ± 13.63 mg/dL) when compared to the calcific plaque sub-group (35.41 ± 13.05 mg/dL), which was statistically significant (p<0.05).

CONCLUSION

sdLDL-C is associated with atherosclerotic carotid plaques, especially the soft plaques on CT angiogram, which are considered to be vulnerable plaques. Thus, calculated sdLDL-C can be utilized as a cost-effective tool to assess plaque vulnerability and monitor hypolipidemic treatment in addition to LDL-C.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

The Influence of Non-High-Density Lipoprotein Cholesterol on the Efficacy of Genotype-Guided Dual Antiplatelet Therapy in Preventing Stroke Recurrence

BACKGROUND AND PURPOSE

Non-high-density lipoprotein cholesterol (non-HDL-C), which represents the total cholesterol content of all pro-atherogenic lipoproteins, has recently been included as a new target for lipid-lowering therapy in high-risk atherosclerotic patients in multiple guidelines. Herein, we aimed to explore the relationship between non-HDL-C level and the efficacy and safety of ticagrelor-aspirin versus clopidogrel-aspirin in preventing stroke recurrence.

METHODS

This study comprised a post hoc analysis of the CHANCE-2 (Ticagrelor or Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events II) trial, from which 5,901 patients with complete data on non-HDL-C were included and categorized by median non-HDL-C levels, using a cutoff of 3.5 mmol/L. The primary efficacy and safety outcomes were recurrent stroke and severe or moderate bleeding within 90 days.

RESULTS

Ticagrelor-aspirin significantly reduced the risk of recurrent stroke in patients with low non-HDL-C (71 [4.8%] vs. 119 [7.7%]; adjusted hazard ratio [HR] 0.54; 95% confidence interval [CI], 0.40-0.74), but not in those with high non-HDL-C (107 [7.3%] vs. 108 [7.6%]; adjusted HR, 0.88; 95% CI, 0.67-1.16), compared with clopidogrel-aspirin (P for interaction=0.010). When analyzed as a continuous variable, the benefit of ticagrelor-aspirin for recurrent stroke decreased as non-HDL-C levels increased. No significant differences in the treatment assignments across the non-HDL-C groups were observed in terms of the rate of severe or moderate bleeding (5 [0.3%] vs. 8 [0.5%] in the low non-HDL-C group; 4 [0.3%] vs. 2 [0.1%] in the high non-HDL-C group; P for interaction=0.425).

CONCLUSION

CHANCE-2 participants with low non-HDL-C levels received more clinical benefit from ticagrelor-aspirin versus clopidogrel-aspirin compared to those with high non-HDL-C, following minor ischemic stroke or transient ischemic attack.

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.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Carotid Stenosis and Stroke: Historical Perspectives Leading to Current Challenges

The carotid artery is unique; it is the only vessel to bifurcate into a bulb larger than itself. The history of its anatomic description, understanding of its pathophysiology and evolution of its imaging are relevant to current controversies regarding measurement of stenosis, surgical/endovascular therapies and medical management of carotid stenosis in stroke prevention. Treatment decisions on millions of symptomatic and asymptomatic patients are routinely based on information from clinical trials from over 30 years ago. This article briefly summarizes the highlights of past research in key areas and discuss how they led to current challenges of diagnosis and treatment.

A novel predictive model based on pericarotid adipose tissue and lumen stenosis for stroke risk in patients with asymptomatic carotid stenosis

The study aimed to investigate the predictive value of clinical characteristics, major computed tomography angiography (CTA) indexes of carotid AS (carotid lumen stenosis and plaque burden), and inflammatory pericarotid adipose tissue for acute stroke risk in patients with a moderate or higher degree of carotid stenosis. In all, 119 patients with unilateral carotid stenosis who underwent head and neck computed tomography angiography were included and assigned to the stroke group or non-stroke group according to magnetic resonance imaging. Pericarotid adipose tissue attenuation value, net enhancement value in the base phase and the enhancement phase, and atherosclerotic features (plaque burden and lumen stenosis) were recorded. Multivariate logistic regression analysis and the operating characteristic curve (ROC) were performed to establish a predictive model for the presence of acute ischemic stroke. ROC analysis showed that pericarotid adipose tissue attenuation value and lumen stenosis were predictive factors for stroke. The AUC of pericarotid adipose tissue attenuation (PCAT) attenuation, lumen stenosis, the novel prediction model independently constructed based on PCAT attenuation, and lumen stenosis resulted in 0.838 (95% CI 0.759-0.899), 0.700 (95% CI 0.826-0.944), and 0.942 (95% CI 0.884-0.977), respectively. The model had a sensitivity and specificity of 0.909 and 0.893, respectively, when the cutoff value was 0.388. We found that the risk model combining pericarotid adipose tissue attenuation value and lumen stenosis has significant predictive values for the presence of symptomatic stroke among patients with a moderate or higher degree of carotid stenosis.

3-D Contrast-Enhanced Fusion Ultrasound for Accurate Volume Assessment of Vessel Lumen and Plaque in Carotid Artery Disease as Compared With Computed Tomography Angiography

OBJECTIVE

Three-dimensional contrast-enhanced fusion ultrasound (CEFUS) of atherosclerotic carotid arteries provides spatial visualization of the vessel lumen, creating a lumenography. As in 3-D computed tomography angiography (CTA), 3-D CEFUS outlines the contrast-filled lumen. Plaque and vessel contours are distinguished in 3-D CEFUS, allowing plaque volume quantification as a valid estimate of carotid plaque burden. Three-dimensional CEFUS is unproven in intermodality studies, vindicating the assessment of 3-D CEFUS applicability and comparing 3-D CEFUS and 3-D CTA lumenography as a proof-of-concept study.

METHODS

Using an ultrasound system with magnetic tracking, a linear array transducer and SonoVue contrast agent, 3-D CEFUS acquisitions were generated by spatial stitching of serial 2-D images. From 3-D CEFUS and 3-D CTA imaging, the atherosclerotic carotid arteries were reconstructed with lumenography in an offline software program for lumen and plaque volume quantification. Bland-Altman analysis was used for inter-image modality agreement.

RESULTS

The study included 39 carotid arteries. Mean lumen and plaque volume in 3-D CEFUS were 0.63 cm3 (standard deviation [SD]: 0.26) and 0.62 cm3 (SD: 0.26), respectively. Lumen volume differences between 3-D CEFUS and 3-D CTA were non-significant, with a mean difference of 0.01 cm3 (SD: 0.02, p = 0.26) and limits of agreement (LoA) range of ±0.11 cm3. Mean plaque volume difference was -0.12 cm3 (SD: 0.19, p = 0.006) with a LoA range of ±0.39 cm3.

CONCLUSION

There was strong agreement in lumenography between 3-D CEFUS and 3-D CTA. The interimage modality difference in plaque volumes was substantial because of challenging vessel wall definition in 3-D CTA. Three-dimensional CEFUS is viable in quantifying carotid plaque volume burden and can potentially monitor plaque development over time.

Association of stroke or death with severity of carotid lesion calcification in patients undergoing carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) for heavily calcified lesions is controversial due to concern for stent failure and increased perioperative stroke risk. However, the degree to which calcification affects outcomes is poorly understood, particularly in transcarotid artery revascularization (TCAR). With the precipitous increase in TCAR use and its expansion to standard surgical-risk patients, we aimed to determine the impact of lesion calcification on CAS outcomes to ensure its safe and appropriate use.

METHODS

We identified patients in the Vascular Quality Initiative who underwent first-time transfemoral CAS (tfCAS) and TCAR between 2016 and 2021. Patients were stratified into groups based on degree of lesion calcification: no calcification, 1% to 50% calcification, 51% to 99% calcification, and 100% circumferential calcification or intraluminal protrusion. Outcomes included in-hospital and 1-year composite stroke/death, as well as individual stroke, death, and myocardial infarction outcomes. Logistic regression was used to evaluate associations between degree of calcification and these outcomes.

RESULTS

Among 21,860 patients undergoing CAS, 28% patients had no calcification, 34% had 1% to 50% calcification, 35% had 51% to 99% calcification, and 3% had 100% circumferential calcification/protrusion. Patients with 51% to 99% and circumferential calcification/protrusion had higher odds of in-hospital stroke/death (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.02-1.6; P = .034; OR, 1.9; 95% CI, 1.1-2.9; P = .004, respectively) compared with those with no calcification. Circumferential calcification was also associated with increased risk for in-hospital myocardial infarction (OR, 3.5; 95% CI, 1.5-8.0; P = .003). In tfCAS patients, only circumferential calcification/protrusion was associated with higher in-hospital stroke/death odds (OR, 2.0; 95% CI, 1.2-3.4; P = .013), whereas for TCAR patients, 51% to 99% calcification was associated with increased odds of in-hospital stroke/death (OR, 1.5; 95% CI, 1.1-2.2; P = .025). At 1 year, circumferential calcification/protrusion was associated with higher odds of ipsilateral stroke/death (12.4% vs 6.6%; hazard ratio, 1.64; P = .002).

CONCLUSIONS

Among patients undergoing CAS, there is an increased risk of in-hospital stroke/death for lesions with >50% calcification or circumferential/protruding plaques. Increasing severity of carotid lesion calcification is a significant risk factor for stroke/death in patients undergoing CAS, regardless of approach.

Comparison of SUVA/V and SUVA-V for Evaluating Atherosclerotic Inflammation in 18F-FDG PET/CT

Purpose

This study aimed to compare the clinical significance of two parameters, division of standardized uptake value (SUV) of target arterial activity by background venous blood pool activity (SUVA/V) and subtraction of background venous blood pool activity from SUV of target arterial activity (SUVA-V) of carotid arteries with atherosclerotic plaques using 18F-fluorodeoxyglucose (FDG) positron emission tomography and computed tomography (PET/CT).

Methods

Patients aged 50 years or more who were diagnosed with carotid artery stenosis of 50% or more with carotid Doppler ultrasonography and had torso 18F-FDG PET/CT were enrolled retrospectively and classified patients who developed cerebrovascular events (CVEs) within 5 years after 18F-FDG PET/CT scan as the active group and patients who did not experience the CVE within 5 years as an inactive group. We calculated SUVA/V and SUVA-V using measurements of SUVmax of carotid arteries and mean SUV of superior vena cava (SVC).

Results

SUVA-V, SUVA-V_high, and SUVA-V_low were significantly higher in the active group than in the inactive group, but neither SUVA/V, SUVA/V_high, nor SUVA/V_low showed significant differences between the active and inactive groups. The difference in rank between groups of SUVA/V_high and SUVA/V_low was greater than the difference in rank between groups of SUVA-V_high and SUVA-V_low. The CVE incidence differed between SUVA/V_high and SUVA/V_low of high carotid FDG uptake, but the CVE incidence did not differ between SUVA-V_high and SUVA-V_low of high carotid FDG uptake.

Conclusion

SUVA-V may be a more rational solution than SUVA/V for evaluating atherosclerotic plaque inflammation on 18F-FDG PET/CT.

Atherosclerotic plaque features relevant to rupture-risk detected by clinical photon-counting CT ex vivo: a proof-of-concept study

BACKGROUND

To identify subjects with rupture-prone atherosclerotic plaques before thrombotic events occur is an unmet clinical need. Thus, this proof-of-concept study aims to determine which rupture-prone plaque features can be detected using clinically available photon-counting computed tomography (PCCT).

METHODS

In this retrospective study, advanced atherosclerotic plaques (ex vivo, paraffin-embedded) from the Carotid Plaque Imaging Project were scanned by PCCT with reconstructed energy levels (45, 70, 120, 190 keV). Density in HU was measured in 97 regions of interest (ROIs) representing rupture-prone plaque features as demonstrated by histopathology (thrombus, lipid core, necrosis, fibrosis, intraplaque haemorrhage, calcium). The relationship between HU and energy was then assessed using a mixed-effects model for each plaque feature.

RESULTS

Plaques from five men (age 79 ± 8 [mean ± standard deviation]) were included in the study. Comparing differences in coefficients (b1diff) of matched ROIs on plaque images obtained by PCCT and histology confirmed that calcium was distinguishable from all other analysed features. Of greater novelty, additional rupture-prone plaque features proved discernible from each other, particularly when comparing haemorrhage with fibrous cap (p = 0.017), lipids (p = 0.003) and necrosis (p = 0.004) and thrombus compared to fibrosis (p = 0.048), fibrous cap (p = 0.028), lipids (p = 0.015) and necrosis (p = 0.017).

CONCLUSIONS

Clinically available PCCT detects not only calcification, but also other rupture-prone features of human carotid plaques ex vivo.

RELEVANCE STATEMENT

Improved atherosclerotic plaque characterisation by photon-counting CT provides the ability to distinguish not only calcium, but also rupture-prone plaque features such as haemorrhage and thrombus. This may potentially improve monitoring and risk stratification of atherosclerotic patients in order to prevent strokes.

KEY POINTS

• CT of atherosclerotic plaques mainly detects calcium. • Many components, such as intra-plaque haemorrhage and lipids, determine increased plaque rupture risk. • Ex vivo carotid plaque photon-counting CT distinguishes haemorrhage and thrombus. • Improved plaque photon-counting CT evaluation may refine risk stratification accuracy to prevent strokes.

Prevention of in-stent restenosis with drug-eluting balloons in patients with postirradiated carotid stenosis accepting percutaneous angioplasty and stenting

OBJECTIVE

To investigate the technical safety and outcome of in-stent restenosis (ISR) prevention with drug-eluting balloon (DEB) in patients with postirradiated carotid stenosis (PIRCS) undergoing percutaneous angioplasty and stenting (PTAS).

METHODS

Between 2017 and 2021, we prospectively recruited patients with severe PIRCS for PTAS. They were randomly separated into two groups based on endovascular techniques performed with and without DEB. Preprocedural and early postprocedural (within 24 hours) MRI, short-term ultrasonography (6 months after PTAS), and long-term CT angiography (CTA)/MR angiography (MRA), 12 months after PTAS, were performed. Technical safety was evaluated based on periprocedural neurological complications and the number of recent embolic ischemic lesions (REIL) in the treated brain territory on diffusion-weighted imaging of early postprocedural MRI.

RESULTS

Sixty-six (30 with and 36 without DEB) subjects were enrolled, with one failure in techniques. For 65 patients in the DEB versus conventional groups, technical neurological symptoms within 1 month (1/29 (3.4%) vs 0/36; P=0.197) and REIL numbers within 24 hours (1.0±2.1 vs 1.3±1.5; P=0.592) after PTAS showed no differences. Peak systolic velocity (PSVs) on short-term ultrasonography was significantly higher in the conventional group (104.13±42.76 vs .81.95±31.35; P=0.023). The degree of in-stent stenosis (45.93±20.86 vs 26.58±8.75; P<0.001) was higher, and there were more subjects (n=8, 38.9% vs 1, 3.4%; P=0.029) with significant ISR (≥ 50%) in the conventional group than in the DEB group on long-term CTA/MRA.

CONCLUSIONS

We observed similar technical safety of carotid PTAS with and without DEBs. The number of cases of significant ISR were fewer and the degree of stenosis of ISR was less in primary DEB-PTAS of PIRCS than for conventional PTAS in the 12-month follow-up.

Effect of plaque morphological characteristics on the outcomes of carotid artery stenting

Carotid artery stenting (CAS) represents today an accepted option for the treatment of severe carotid artery stenosis. The evolution of materials, techniques, perioperative medical management and patients' selection, has allowed to progressively reduce CAS complications. However, the main drawback of CAS is still represented by the risk of cerebral embolization, that may occur during several steps of the procedure and also in the early postoperative period. Preoperative carotid plaque morphological characteristics may have a great role in determining the risk of embolization during CAS. This review summarizes the current knowledge on carotid plaque characteristics that may influence the risk of complication during CAS. This information may be important for the optimization of CAS patients' selection and adaptation of the materials and techniques.

Heavy macrophage infiltration identified by optical coherence tomography relates to plaque rupture

OBJECTIVE

Risk stratification plays a critical role in patients with asymptomatic carotid atherosclerotic stenosis. Heavy macrophage infiltration (HMC) is an important factor of plaque destabilization. However, in vivo imaging technologies and screening criteria for HMC remain limited. We aimed to (i) introduce algorithms for in vivo detection of macrophage infiltrations using optical coherence tomography (OCT) and (ii) to investigate the threshold of HMC and its association with plaque vulnerability.

METHODS

Ex vivo OCT images were co-registered with histopathology in 282 cross-sectional pairs from 19 carotid endarterectomy specimens. Of these, 197 randomly selected pairs were employed to define the parameters, and the remaining 85 pairs were used to evaluate the accuracy of the OCT-based algorithm in detecting macrophage infiltrations. Clinical analysis included 93 patients receiving carotid OCT evaluation. The prevalence and burden of macrophage infiltration were analyzed. Multivariable and subgroup analysis were performed to investigate the association between HMC and plaque rupture.

RESULTS

The sensitivity and specificity of algorithm for detecting macrophage infiltration were 88.0% and 74.9%, respectively. Of 93 clinical patients, ruptured plaques exhibited higher prevalence of macrophage infiltration than nonruptured plaques (83.7% [36/43] vs 32.0% [16/50], p < 0.001). HMC was identified when the macrophage index was greater than 60.2 (sensitivity = 74.4%, specificity = 84.0%). Multivariable analysis showed that HMC and multiple calcification were independent risk factors for non-lipid-rich plaque rupture.

INTERPRETATION

This study provides a novel approach and screening criteria for HMC, which might be valuable for atherosclerotic risk stratification.

Carotid Artery Stenting Versus Carotid Artery Endarterectomy in Asymptomatic Severe Carotid Stenosis: An Updated Meta-Analysis

Carotid artery stenting (CAS) and carotid artery endarterectomy (CEA) are revascularization options for the management of severe carotid disease in asymptomatic patients. We aimed to compare the peri-procedural outcomes of the two modalities. A systematic review of the databases PUBMED, EBSCO, and Cochrane Library was performed. All the studies that reported periprocedural outcomes (within 30 days) in asymptomatic carotid stenosis patients were included in the meta-analysis. Random effects models with inverse-variance weighting were used to estimate pooled risk ratios (RRs) to compare the outcomes. Fifteen studies (including seven randomized controlled trials) met the inclusion criteria. A total of 15251 patients were included, out of which 6419 (42%) underwent CAS and 8832 (57.9%) underwent CEA. There was no statistical difference in the primary composite outcome of death/stroke/myocardial infarction (MI) (RR 1.02, 95% CI [0.69-1.51], p 0.93). No difference was found in the secondary outcome of all-cause mortality. CAS was associated with a slightly lower risk of MI and cranial nerve palsy. CAS was associated with a slightly higher risk of stroke with no difference in the occurrence of disabling stroke or ipsilateral stroke. In general terms, the study confirms equipoise in the two treatment strategies with a higher risk of MI and cranial nerve palsy with CEA and a higher risk of non-disabling stroke with CAS.

Combined near infrared photoacoustic imaging and ultrasound detects vulnerable atherosclerotic plaque

Atherosclerosis is an inflammatory process resulting in the deposition of cholesterol and cellular debris, narrowing of the vessel lumen and clot formation. Characterization of the morphology and vulnerability of the lesion is essential for effective clinical management. Here, near-infrared auto-photoacoustic (NIRAPA) imaging is shown to detect plaque components and, when combined with ultrasound imaging, to differentiate stable and vulnerable plaque. In an ex vivo study of photoacoustic imaging of excised plaque from 25 patients, 88.2% sensitivity and 71.4% specificity were achieved using a clinically-relevant protocol. In order to determine the origin of the NIRAPA signal, immunohistochemistry, spatial transcriptomics and spatial proteomics were co-registered with imaging and applied to adjacent plaque sections. The highest NIRAPA signal was spatially correlated with bilirubin and associated blood-based residue and with the cytoplasmic contents of inflammatory macrophages bearing CD74, HLA-DR, CD14 and CD163 markers. In summary, we establish the potential to apply the NIRAPA-ultrasound imaging combination to detect vulnerable carotid plaque and a methodology for fusing molecular imaging with spatial transcriptomic and proteomic methods.

Progress of Ultrasound Techniques in the Evaluation of Carotid Vulnerable Plaque Neovascularization

BACKGROUND

The rupture and detachment of unstable plaques in the carotid artery can cause embolism in the cerebral artery, leading to acute cerebrovascular events. Intraplaque neovascularization (IPN) is a very important contributor to carotid plaque instability, and its evolution plays a key role in determining the outcome of vulnerable plaques. Ultrasound techniques, represented by contrast-enhanced ultrasound (CEUS) and superb microvascular imaging (SMI), are reported to be non-invasive, rapid, and effective techniques for the semi-quantitative or quantitative evaluation for IPN. Although ultrasound techniques have been widely applied in the detection of carotid plaque stability, it has been limited owing to the lack of unified IPN quantitative standards.

SUMMARY

This review summarizes the application and semi-quantitative/quantitative diagnostic standards of ultrasound techniques in evaluating IPN and looks forward to the prospects of the future research. With the development of novel techniques like artificial intelligence, ultrasound will offer appropriate selections for achieving more accuracy diagnosis.

KEY MESSAGES

A large number of studies have used CEUS and SMI to detect IPN and perform semi-quantitative grading to predict the occurrence of diseases such as stroke and to accurately assess drug efficacy based on rating changes. These studies have made great progress at this stage, but more accurate and intelligent quantitative imaging methods should become the future development goal.

Rates of Stroke in Patients With Different Presentations of Carotid Artery Stenosis

OBJECTIVE

Carotid artery stenosis may present without the classical symptoms of transient ischaemic attack or stroke but the rates of stroke for these presentations is unknown. The aim of this study was to examine the rates of stroke in patients with different presentations of carotid artery stenosis.

METHODS

A multicentre prospective cohort study was conducted across three Australian vascular centres with low rates of surgical treatment of patients without transient ischaemic attack or stroke. Patients with a 50 - 99% carotid artery stenosis presenting with non-focal symptoms (e.g., dizziness or syncope; n = 47), prior contralateral carotid endarterectomy (n = 71), prior ipsilateral symptoms more than six months earlier (n = 82), and no symptoms (n = 304) were recruited. The primary outcome was ipsilateral ischaemic stroke. Secondary outcomes were any ischaemic stroke and cardiovascular death. Data were analysed using Cox proportional hazard and Kaplan-Meier analyses.

RESULTS

Between 2002 and 2020, 504 patients were enrolled (mean age 71 years, 30% women) and followed for a median of 5.1 years (interquartile range 2.5, 8.8; 2 981 person years). Approximately 82% were prescribed antiplatelet therapy, 84% were receiving at least one antihypertensive drug, and 76% were prescribed a statin at entry. After five years the incidence of ipsilateral stroke was 6.5% (95% confidence interval [CI] 4.3 - 9.5). There were no statistically significant differences in the annual rate of ipsilateral stroke among people with non-focal symptoms (2.1%; 95% CI 0.8 - 5.7), prior contralateral carotid endarterectomy (0.2%; 0.03 - 1.6) or ipsilateral symptoms > 6 months prior (1.0%; 0.4 - 2.5) compared with those with no symptoms (1.2%; 0.7 - 1.8; p = .19). There were no statistically significant differences in secondary outcomes across groups.

CONCLUSION

This cohort study showed no large differences in stroke rates among people with different presentations of carotid artery stenosis.

Imaging modality-dependent carotid stenosis severity variations against intravascular ultrasound as a reference: Carotid Artery intravasculaR Ultrasound Study (CARUS)

PURPOSE

Different non-invasive and invasive imaging modalities are used to determine carotid artery stenosis severity that remains a principal parameter in clinical decision-making. We compared stenosis degree obtained with different modalities against vascular imaging gold standard, intravascular ultrasound, IVUS.

METHODS

300 consecutive patients (age 47-83 years, 192 men, 64% asymptomatic) with carotid artery stenosis of " ≥ 50%" referred for potential revascularization received as per study protocol (i) duplex ultrasound (DUS), (ii) computed tomography angiography (CTA), (iii) intraarterial quantitative angiography (iQA) and (iv) and (iv) IVUS. Correlation of measurements with IVUS (r), proportion of those concordant (within 10%) and proportion of under/overestimated were calculated along with recipient-operating-characteristics (ROC).

RESULTS

For IVUS area stenosis (AS) and IVUS minimal lumen area (MLA), there was only a moderate correlation with DUS velocities (peak-systolic, PSV; end-diastolic, EDV; r values of 0.42-0.51, p < 0.001 for all). CTA systematically underestimated both reference area and MLA (80.4% and 92.3% cases) but CTA error was lesser for AS (proportion concordant-57.4%; CTA under/overestimation-12.5%/30.1%). iQA diameter stenosis (DS) was found concordant with IVUS in 41.1% measurements (iQA under/overestimation 7.9%/51.0%). By univariate model, PSV (ROC area-under-the-curve, AUC, 0.77, cutoff 2.6 m/s), EDV (AUC 0.72, cutoff 0.71 m/s) and CTA-DS (AUC 0.83, cutoff 59.6%) were predictors of ≥ 50% DS by IVUS (p < 0.001 for all). Best predictor, however, of ≥ 50% DS by IVUS was stenosis severity evaluation by automated contrast column density measurement on iQA (AUC 0.87, cutoff 68%, p < 0.001). Regarding non-invasive techniques, CTA was the only independent diagnostic modality against IVUS on multivariate model (p = 0.008).

CONCLUSION

IVUS validation shows significant imaging modality-dependent variations in carotid stenosis severity determination.

Novel Therapeutic Approaches to Prevent Atherothrombotic Ischemic Stroke in Patients with Carotid Atherosclerosis

Atherothrombotic stroke represents approximately 20% of all ischemic strokes. It is caused by large-artery atherosclerosis, mostly in the internal carotid artery, and it is associated with a high risk of early recurrence. After an ischemic stroke, tissue plasminogen activator is used in clinical practice, although it is not possible in all patients. In severe clinical situations, such as high carotid stenosis (≥70%), revascularization by carotid endarterectomy or by stent placement is carried out to avoid recurrences. In stroke prevention, the pharmacological recommendations are based on antithrombotic, lipid-lowering, and antihypertensive therapy. Inflammation is a promising target in stroke prevention, particularly in ischemic strokes associated with atherosclerosis. However, the use of anti-inflammatory strategies has been scarcely studied. No clinical trials are clearly successful and most preclinical studies are focused on protection after a stroke. The present review describes novel therapies addressed to counteract inflammation in the prevention of the first-ever or recurrent stroke. The putative clinical use of broad-spectrum and specific anti-inflammatory drugs, such as monoclonal antibodies and microRNAs (miRNAs) as regulators of atherosclerosis, will be outlined. Further studies are necessary to ascertain which patients may benefit from anti-inflammatory agents and how.

The Association Between Hemoglobin Glycation Index and Carotid Artery Plaque in Patients With Coronary Heart Disease

This study aimed to examine the association between the hemoglobin glycation index (HGI) and carotid artery plaque (CAP) in patients with coronary heart disease (CHD). We conducted a cross-sectional analysis of 10,778 patients with CHD. The participants were divided into three groups by HGI tertiles (T1 HGI<-0.44, T2 -0.44 ≤ HGI ≤ 0.15, T3 HGI>0.15). The presence of CAP was used to diagnose by carotid ultrasonography. Logistic regression analysis was used to analyze the association between the HGI and CAP. The association between HGI and CAP was also assessed according to sex, age, smoking status, and drinking status. We further assessed the association between HGI and the ultrasound characteristics of CAP. The baseline analysis showed substantial differences in relevant parameters between the three groups of patients with CHD according to the tertiles of the HGI. Multivariate logistic regression analysis showed that HGI was significantly associated with CAP (odds ratio [OR] 1.32; 95% confidence interval [CI] 1.26-1.39). The association between HGI and CAP exists among different sex, age, smoking, and drinking status. Furthermore, there was a significant and positive association between HGI and all four different echogenicities of the CAP.

The Effect of Circle of Willis Morphology on Retinal Blood Flow in Patients with Carotid Stenosis Measured by Optical Coherence Tomography Angiography

The Circle of Willis (CoW) is the main collateral system, and its morphological variants are more common in patients who have severe carotid artery stenosis. Earlier data suggest that optical coherence tomography angiography (OCTA) may help to assess the changes in cerebral vascular perfusion by imaging the retinal blood flow. In this single-center prospective clinical study, patients scheduled for carotid endarterectomy (CEA) underwent preoperative computed tomography angiography (CTA) of the extra- and intracranial cerebral circulation. OCTA imaging was performed one week before surgery and postoperatively one month later. The patients were divided into two subgroups based on CTA evaluation of CoW: compromised CoW or non-compromised CoW (containing hypoplastic and normal segments). The effect of the patient's age, OCTA scan quality (SQ), CoW morphology, laterality, and surgery on superficial capillary vessel density (VD) in the macula were assessed in multivariable regression models using linear mixed models. We found that VD significantly decreased with aging (-0.12%; 95%CI: -0.07--0.15; p < 0.001) and was significantly higher in patients with non-compromised CoW morphology (by 0.87% 95%CI (0.26-1.50); p = 0.005). After CEA, retinal blood flow significantly improved by 0.71% (95%CI: 0.18-1.25; p = 0.01). These results suggest that in the case of carotid artery occlusion, patients with non-compromised CoW have more preserved ocular blood flow than subjects with compromised CoW due to remodeling of the intra-orbital blood flow. Measuring the retinal blood flow might be used as a relevant and sensitive indicator of collateral cerebrovascular circulation.

Contemporary Treatment of the Asymptomatic Carotid Patient

Stroke is a persistent leading cause of morbidity and mortality, and carotid artery atherosclerosis remains a treatable cause of future stroke. Although most patients with asymptomatic carotid artery disease may be at a relatively low risk for future stroke, most completed strokes are unheralded; thus, the identification and appropriate treatment of patients with asymptomatic carotid artery disease remains a critical part of overall stroke prevention. Select patients with asymptomatic carotid artery stenosis with an increased risk of future stroke based on the degree of stenosis and other imaging or patient-related characteristics are appropriate to consider for carotid artery intervention.

Focus on the Most Common Paucisymptomatic Vasculopathic Population, from Diagnosis to Secondary Prevention of Complications

Middle-aged adults can start to be affected by some arterial diseases (ADs), such as abdominal aortic or popliteal artery aneurysms, lower extremity arterial disease, internal carotid, or renal artery or subclavian artery stenosis. These vasculopathies are often asymptomatic or paucisymptomatic before manifesting themselves with dramatic complications. Therefore, early detection of ADs is fundamental to reduce the risk of major adverse cardiovascular and limb events. Furthermore, ADs carry a high correlation with silent coronary artery disease (CAD). This study focuses on the most common ADs, in the attempt to summarize some key points which should selectively drive screening. Since the human and economic possibilities to instrumentally screen wide populations is not evident, deep knowledge of semeiotics and careful anamnesis must play a central role in our daily activity as physicians. The presence of some risk factors for atherosclerosis, or an already known history of CAD, can raise the clinical suspicion of ADs after a careful clinical history and a deep physical examination. The clinical suspicion must then be confirmed by a first-level ultrasound investigation and, if so, adequate treatments can be adopted to prevent dreadful complications.

What are the benefits and drawbacks of statins in carotid artery disease? A perspective review

INTRODUCTION

The prevalence of carotid artery stenosis in the general population is approximately 3%, but approximately 20% among people with acute ischemic stroke. Statins are recommended by multiple international guidelines as the drug of choice for lipid control in people with asymptomatic or symptomatic carotid artery stenosis due to their lipid-lowering and other pleiotropic effects.

AREAS COVERED

This review discusses the guidelines for statin usage as a cornerstone in the prevention and management of atherosclerotic carotid artery disease and the impact of statins on stroke incidence and mortality. Statin side effects, alternative therapy, and genetic polymorphisms are reviewed.

EXPERT OPINION

Statin therapy is associated with a decreased incidence of stroke and mortality as well as improved outcomes for patients treated with carotid revascularization. Statins are a safe and effective class of medications, but the initiation of therapy warrants close monitoring to avoid rare and potentially serious side effects. Lack of clinical efficacy or the presence of side effects suggests a need for treatment with an alternative therapy such as PCSK9 inhibitors. Understanding the interplay between the mechanisms of statins and PCSK9 inhibition therapies will allow optimal benefits while minimizing risks. Future research into genetic polymorphisms may improve patient selection for personalized therapy.

High-risk carotid plaques and incident ischemic stroke in patients with atrial fibrillation in the Cardiovascular Health Study

BACKGROUND AND PURPOSE

Whether carotid artery disease could improve stroke risk stratification tools in patients with atrial fibrillation (AF) remains uncertain. This study was undertaken to investigate the risk of ischemic stroke associated with occlusive and nonocclusive carotid atherosclerotic disease in patients with AF in the prospective population-based Cardiovascular Health Study.

METHODS

We included participants aged ≥65 years with AF. We used multivariable Cox regression analysis to explore the risk of ischemic stroke associated with the percentage of carotid stenosis, plaque irregularity, echogenicity, and vulnerability (markedly irregular, ulcerated, or hypoechoic plaques).

RESULTS

A total of 1398 participants were included (55.2% female, 61.7% aged 65-74 years). The maximum carotid stenosis was <50%, 50%-99%, and 100% in 94.5%, 5%, and 0.5% of participants, respectively. High-risk plaques based on echogenicity and plaque irregularity were found in 25.6% and 8.9% of participants, respectively. After a median follow-up of 10.9 years (interquartile range = 7.5-15.6), 298 ischemic strokes were recorded. There was no difference in the incidence of ischemic stroke according to the degree of carotid artery stenosis (p = 0.44), plaque echogenicity (low vs. high risk, p = 0.68), plaque irregularity (low vs. high risk, p = 0.55), and plaque vulnerability (p = 0.86). The CHA₂DS₂-VASc score was associated with an increased risk of ischemic stroke (adjusted hazard ratio = 1.28, 95% confidence interval = 1.18-1.40, p < 0.001). Both maximum grade of stenosis and plaque vulnerability were not associated with incident ischemic stroke (all p > 0.05).

CONCLUSIONS

Neither the degree of carotid stenosis nor the presence of vulnerable plaques was associated with incident ischemic stroke in this cohort of individuals with AF. This suggests that carotid disease was probably not a significant contributor to ischemic stroke in this population.

Computed tomography angiography-based radiomics model for predicting carotid atherosclerotic plaque vulnerability

Vulnerable carotid atherosclerotic plaque (CAP) significantly contributes to ischemic stroke. Neovascularization within plaques is an emerging biomarker linked to plaque vulnerability that can be detected using contrast-enhanced ultrasound (CEUS). Computed tomography angiography (CTA) is a common method used in clinical cerebrovascular assessments that can be employed to evaluate the vulnerability of CAPs. Radiomics is a technique that automatically extracts radiomic features from images. This study aimed to identify radiomic features associated with the neovascularization of CAP and construct a prediction model for CAP vulnerability based on radiomic features. CTA data and clinical data of patients with CAPs who underwent CTA and CEUS between January 2018 and December 2021 in Beijing Hospital were retrospectively collected. The data were divided into a training cohort and a testing cohort using a 7:3 split. According to the examination of CEUS, CAPs were dichotomized into vulnerable and stable groups. 3D Slicer software was used to delineate the region of interest in CTA images, and the Pyradiomics package was used to extract radiomic features in Python. Machine learning algorithms containing logistic regression (LR), support vector machine (SVM), random forest (RF), light gradient boosting machine (LGBM), adaptive boosting (AdaBoost), extreme gradient boosting (XGBoost), and multi-layer perception (MLP) were used to construct the models. The confusion matrix, receiver operating characteristic (ROC) curve, accuracy, precision, recall, and f-1 score were used to evaluate the performance of the models. A total of 74 patients with 110 CAPs were included. In all, 1,316 radiomic features were extracted, and 10 radiomic features were selected for machine-learning model construction. After evaluating several models on the testing cohorts, it was discovered that model_RF outperformed the others, achieving an AUC value of 0.93 (95% CI: 0.88-0.99). The accuracy, precision, recall, and f-1 score of model_RF in the testing cohort were 0.85, 0.87, 0.85, and 0.85, respectively. Radiomic features associated with the neovascularization of CAP were obtained. Our study highlights the potential of radiomics-based models for improving the accuracy and efficiency of diagnosing vulnerable CAP. In particular, the model_RF, utilizing radiomic features extracted from CTA, provides a noninvasive and efficient method for accurately predicting the vulnerability status of CAP. This model shows great potential for offering clinical guidance for early detection and improving patient outcomes.

Combined near infrared photoacoustic imaging and ultrasound detects vulnerable atherosclerotic plaque

Atherosclerosis is an inflammatory process resulting in the deposition of cholesterol and cellular debris, narrowing of the vessel lumen and clot formation. Characterization of the morphology and vulnerability of the lesion is essential for effective clinical management. Photoacoustic imaging has sufficient penetration and sensitivity to map and characterize human atherosclerotic plaque. Here, near infrared photoacoustic imaging is shown to detect plaque components and, when combined with ultrasound imaging, to differentiate stable and vulnerable plaque. In an ex vivo study of photoacoustic imaging of excised plaque from 25 patients, 88.2% sensitivity and 71.4% specificity were achieved using a clinically-relevant protocol. In order to determine the origin of the near-infrared auto-photoacoustic (NIRAPA) signal, immunohistochemistry, spatial transcriptomics and proteomics were applied to adjacent sections of the plaque. The highest NIRAPA signal was spatially correlated with bilirubin and associated blood-based residue and inflammatory macrophages bearing CD74, HLA-DR, CD14 and CD163 markers. In summary, we establish the potential to apply the NIRAPA-ultrasound imaging combination to detect vulnerable carotid plaque.

Lipoprotein(a) Is Associated With the Progression and Vulnerability of New-Onset Carotid Atherosclerotic Plaque

BACKGROUND

Although important progress has been made in understanding Lp(a) (lipoprotein[a])-mediated stroke risk, the contribution of Lp(a) to the progression of vulnerable plaque features associated with stroke risk remains unclear. This study aims to evaluate whether Lp(a) is associated with carotid plaque progression, new-onset plaque features, and plaque vulnerability in a prospective community-based cohort study.

METHODS

Baseline Lp(a) levels were measured using latex-enhanced turbidimetric immunoassay among 804 participants aged 45 to 74 years and free of cardiovascular disease in the Chinese Multi-provincial Cohort Study-Beijing project. Carotid atherosclerosis was measured twice by B-mode ultrasonography over a 10-year interval during the 2002 and 2012 surveys to assess the progression of total, vulnerable and stable plaques, and plaque vulnerability. The total plaque area and plaque vulnerability score were calculated.

RESULTS

The median baseline Lp(a) level was 10.20 mg/dL (interquartile range, 6.20 to 17.18 mg/dL). Modified Poisson regression analysis showed that Lp(a) ≥50 mg/dL was significantly associated with 10-year progression of total carotid plaque (relative risk [RR], 1.41 [95% CI, 1.21-1.64]; E-value=2.17), vulnerable plaque (RR, 1.93 [95% CI, 1.54-2.41]), and stable plaque (RR, 1.51 [95% CI, 1.11-2.07]) compared with Lp(a) <50 mg/dL. Moreover, among participants without plaque at baseline, Lp(a) ≥50 mg/dL was related to an increased total plaque area (β=0.36 [95% CI, 0.06-0.65]; P=0.018) and increased plaque vulnerability score (β=0.30 [95% CI, 0.01-0.60]; P=0.045) in multivariable linear regression.

CONCLUSIONS

Elevated Lp(a) levels were associated with 10-year carotid plaque progression and plaque vulnerability, providing a basis for Lp(a) as a treatment target for stroke prevention.

New Technologies in the Assessment of Carotid Stenosis: Beyond the Color-Doppler Ultrasound-High Frame Rate Vector-Flow and 3D Arterial Analysis Ultrasound

Atherosclerotic plaque in the carotid artery is the main cause of ischemic stroke, with a high incidence rate among people over 65 years. A timely and precise diagnosis can help to prevent the ischemic event and decide patient management, such as follow up, medical, or surgical treatment. Presently, diagnostic imaging techniques available include color-Doppler ultrasound, as a first evaluation technique, computed tomography angiography, which, however, uses ionizing radiation, magnetic resonance angiography, still not in widespread use, and cerebral angiography, which is an invasively procedure reserved for therapeutically purposes. Contrast-enhanced ultrasound is carving out an important and emerging role which can significantly improve the diagnostic accuracy of an ultrasound. Modern ultrasound technologies, still not universally utilized, are opening new horizons in the arterial pathologies research field. In this paper, the technical development of various carotid artery stenosis diagnostic imaging modalities and their impact on clinical efficacy is thoroughly reviewed.

Enhanced Carotid Plaque Echolucency Is Associated with Reduced Cognitive Performance in Elderly Patients with Atherosclerotic Disease Independently on Metabolic Profile

Vulnerable carotid atherosclerotic plaques are related to an increased risk of cognitive impairment and dementia in advanced age. In this study, we investigated the relationship between the echogenicity of carotid plaques and cognitive performance in patients with asymptomatic carotid atherosclerotic plaques. We enrolled 113 patients aged 65 years or more (72.4 ± 5.9 years) who underwent carotid duplex ultrasound to evaluate plaque echogenicity by grey-scale median (GSM) and neuropsychological tests to assess cognitive function. The GSM values at baseline were inversely correlated with the number of seconds required to complete Trail Makin Test (TMT) A (rho: −0.442; p < 0.0001), TMT B (rho: −0.460; p < 0.0001) and TMT B-A (rho: −0.333; p < 0.0001) and directly correlated with Mini Mental State Examination (MMSE) and Verbal Fluency Test (VFT) score (rho: 0.217; p = 0.021 and rho: 0.375; p < 0.0001, respectively) and the composite cognitive z-score (rho: 0.464; p < 0.0001). After a mean period of 3.5 ± 0.5 years, 55 patients were reevaluated according to the same baseline study protocol. Patients with baseline GSM value higher than the median value of 29 did not show any significant variation in the z-score. Instead, those with GSM ≤ 29 showed a significant worsening of z-score (−1.2; p = 0.0258). In conclusion, this study demonstrates the existence of an inverse relationship between the echolucency of carotid plaques and cognitive function in elderly patients with atherosclerotic carotid disease. These data suggest that the assessment of plaque echogenicity if used appropriately, might aid in identifying subjects at increased risk for cognitive dysfunction.

Fluid structure interaction analysis to stratify the behavior of different atheromatous carotid plaques

BACKGROUND

In asymptomatic carotid stenosis (ACS), different plaque types, i.e. lipidic (LP), fibrous (FP), and calcific (CP), could have different hemodynamic and structural behaviors.

METHODS

Different carotid plaques, reconstructed from medical imaging of ACS >70%, were analyzed by computing fluid structure interaction (FSI), modeling the spatial distribution of wall shear stresses (WSS), plaque displacements (D), von Mises stresses (VMS), and absorbed elastic energy (AEE) together with their maximum-in-space values at the systole (WSS<inf>syst</inf>, D<inf>syst</inf>, VMS<inf>syst</inf> and AEE<inf>syst</inf>).

RESULTS

WSS resulted significantly higher in CP, whereas D and VMS showed the highest values for LP. Regarding AEE<inf>syst</inf> stored by the plaques, LP absorbed in average 2320 J/m³, FP 408 J/m³ (470%) and CP 99 J/m³ (2240%), (P<0.01, P<0.01, and P<0.01, respectively).

CONCLUSIONS

Depending upon their nature, plaques store different deformations and inner distributions of forces, thus potentially influencing their vulnerability.

Identifying vulnerable plaques: A 3D carotid plaque radiomics model based on HRMRI

Background

Identification of vulnerable carotid plaque is important for the treatment and prevention of stroke. In previous studies, plaque vulnerability was assessed qualitatively. We aimed to develop a 3D carotid plaque radiomics model based on high-resolution magnetic resonance imaging (HRMRI) to quantitatively identify vulnerable plaques.

Methods

Ninety patients with carotid atherosclerosis who underwent HRMRI were randomized into training and test cohorts. Using the radiological characteristics of carotid plaques, a traditional model was constructed. A 3D carotid plaque radiomics model was constructed using the radiomics features of 3D T₁-SPACE and its contrast-enhanced sequences. A combined model was constructed using radiological and radiomics characteristics. Nomogram was generated based on the combined models, and ROC curves were utilized to assess the performance of each model.

Results

48 patients (53.33%) were symptomatic and 42 (46.67%) were asymptomatic. The traditional model was constructed using intraplaque hemorrhage, plaque enhancement, wall remodeling pattern, and lumen stenosis, and it provided an area under the curve (AUC) of 0.816 vs. 0.778 in the training and testing sets. In the two cohorts, the 3D carotid plaque radiomics model and the combined model had an AUC of 0.915 vs. 0.835 and 0.957 vs. 0.864, respectively. In the training set, both the radiomics model and the combination model outperformed the traditional model, but there was no significant difference between the radiomics model and the combined model.

Conclusions

HRMRI-based 3D carotid radiomics models can improve the precision of detecting vulnerable carotid plaques, consequently improving risk classification and clinical decision-making in patients with carotid stenosis.

Multimodal ultrasound-based carotid plaque risk biomarkers predict poor functional outcome in patients with ischemic stroke or TIA

BACKGROUND

Carotid vulnerable plaque is an important risk factor for stroke occurrence and recurrence. However, the relationship between risk parameters related to carotid vulnerable plaque (plaque size, echogenicity, intraplaque neovascularization, and plaque stiffness) and neurological outcome after ischemic stroke or TIA is unclear. This study investigates the value of multimodal ultrasound-based carotid plaque risk biomarkers to predict poor short-term functional outcome after ischemic stroke or TIA.

METHODS

This study was a single-center, prospective, continuous, cohort study to observe the occurrence of adverse functional outcomes (mRS 2-6/3-6) 90 days after ischemic stroke or TIA in patients, where the exposure factors in this study were carotid plaque ultrasound risk biomarkers and the risk factors were sex, age, disease history, and medication history. Patients with ischemic stroke or TIA (mRS ≤3) whose ipsilateral internal carotid artery stenosis was ≥50% within 30 days were included. All patients underwent multimodal ultrasound at baseline, including conventional ultrasound, superb microvascular imaging (SMI), and shear wave elastography (SWE). Continuous variables were divided into four groups at interquartile spacing for inclusion in univariate and multifactorial analyses. After completion of a baseline ultrasound, all patients were followed up at 90 days after ultrasound, and patient modified neurological function scores (mRSs) were recorded. Multivariate Cox regression and ROC curves were used to assess the risk factors and predictive power for predicting poor neurological function.

RESULTS

SMI revealed that 20 (30.8%) patients showed extensive neovascularization in the carotid plaque, and 45 (69.2%) patients showed limited neovascularization in the carotid plaque. SWE imaging showed that the mean carotid plaque stiffness was 51.49 ± 18.34 kPa (23.19-111.39 kPa). After a mean follow-up of 90 ± 14 days, a total of 21 (32.3%) patients had a mRS of 2-6, and a total of 10 (15.4%) patients had a mRS of 3-6. Cox regression analysis showed that the level of intraplaque neovascularization and plaque stiffness were independent risk factors for a mRS of 2-6, and the level of intraplaque neovascularization was an independent risk factor for a mRS of 3-6. After correcting for confounders, the HR of intraplaque neovascularization level and plaque stiffness predicting a mRS 2-6 was 3.06 (95% CI 1.05-12.59, P = 0.041) and 0.51 (95% CI 0.31-0.83, P = 0.007), respectively; the HR of intraplaque neovascularization level predicting a mRS 3-6 was 6.11 (95% CI 1.19-31.45, P = 0.031). For ROC curve analysis, the mRSs for intraplaque neovascularization level, plaque stiffness, and combined application to predict 90-day neurological outcome ranged from 2 to 6, with AUCs of 0.73 (95% CI 0.59-0.87), 0.76 (95% CI 0.64-0.89) and 0.85 (95% CI 0.76-0.95), respectively. The mRSs for the intraplaque neovascularization level to predict 90-day neurological outcome ranged from 3 to 6, with AUCs of 0.79 (95% CI 0.63-0.95).

CONCLUSION

Intraplaque neovascularization level and plaque stiffness may be associated with an increased risk of poor short-term functional outcome after stroke in patients with recent anterior circulation ischemic stroke due to carotid atherosclerosis. The combined application of multiple parameters has efficacy in predicting poor short-term functional outcome after stroke.

The efficacy and safety of Chinese herbal medicine as an add-on therapy for type 2 diabetes mellitus patients with carotid atherosclerosis: An updated meta-analysis of 27 randomized controlled trials

Background: Type 2 diabetes mellitus (T2DM) is a clinical metabolic syndrome characterized by persistent hyperglycemia. Patients with T2DM are more likely to have carotid atherosclerosis (CAS), which can lead to dizziness, amaurosis or even stroke. Chinese herbal medicine (CHM) has shown possible efficacy and safety in treating T2DM patients with CAS. However, the existing evidence was not robust enough and the results were out of date. Objective: This meta-analysis aimed to summarize the current evidence and systematically evaluate the effects of CHM on carotid plaque, glucose and lipid metabolism and vascular endothelial parameters in T2DM patients with CAS, providing a reference for subsequent research and clinical practice. Methods: This study was registered in PROSPERO as CRD42022346274. Both Chinese and English databases were searched from their inceptions to 16 July 2022. All retrieved studies were screened according to inclusion and exclusion criteria. Randomized controlled trials (RCTs) using oral CHM to treat T2DM patients with CAS were included. The literature quality was assessed using the risk of bias assessment tool in the Cochrane Handbook. Data extraction was conducted on the selected studies. Review Manager 5.4 and Stata 16.0 were used for meta-analysis. Sources of heterogeneity were explored by meta-regression or subgroup analysis. Funnel plot and Egger's test were used to assess publication bias and the evidence quality was assessed by Grading of Recommendations Assessment, Development and Evaluation (GRADE). Results: 27 eligible studies, involving 2638 patients, were included in this study. Compared with western medicine (WM) alone, the addition of CHM was significantly better in improving carotid intima-media thickness (CIMT) [mean difference (MD) = -0.11mm, 95% confidence interval (CI): -0.15 to -0.07, p < 0.01], carotid plaque Crouse score [MD = -1.21, 95%CI: -1.35 to -1.07, p < 0.01], total cholesterol (TC) [MD = -0.34 mmol/L, 95%CI: -0.54 to -0.14, p < 0.01], triglyceride (TG) [MD = -0.26 mmol/L, 95%CI: -0.37 to -0.15, p < 0.01], low-density lipoprotein cholesterol (LDL-C) [MD = -0.36 mmol/L, 95%CI: -0.47 to -0.25, p < 0.01], high-density lipoprotein cholesterol (HDL-C) [MD = 0.22 mmol/L, 95%CI: 0.13 to 0.30, p < 0.01], glycated hemoglobin (HbA1c) [MD = -0.36%, 95%CI: -0.51 to -0.21, p < 0.01], fasting blood glucose (FBG) [MD = -0.33 mmol/L, 95%CI: -0.50 to -0.16, p < 0.01], 2-h postprandial glucose (2hPG) [MD = -0.52 mmol/L, 95%CI: -0.95 to -0.09, p < 0.01], homeostasis model assessment of insulin resistance (HOMA-IR) [standardized mean difference (SMD) = -0.88, 95%CI: -1.36 to -0.41, p < 0.01] and homeostasis model assessment of beta-cell function (HOMA-β) [MD = 0.80, 95%CI: 0.51 to 1.09, p < 0.01]. Due to the small number of included studies, it is unclear whether CHM has an improving effect on nitric oxide (NO), endothelin-1 (ET-1), peak systolic velocity (PSV) and resistance index (RI). No serious adverse events were observed. Conclusion: Based on this meta-analysis, we found that in the treatment of T2DM patients with CAS, combined with CHM may have more advantages than WM alone, which can further reduce CIMT and carotid plaque Crouse score, regulate glucose and lipid metabolism, improve insulin resistance and enhance islet β-cell function. Meanwhile, CHM is relatively safe. However, limited by the quality and heterogeneity of included studies, the efficacy and safety of CHM remain uncertain. More high-quality studies are still needed to provide more reliable evidence for the clinical application of CHM. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022346274.

Non-stenosing carotid artery plaques in embolic stroke of undetermined source: a retrospective analysis

BACKGROUND

We aim to identify the association between high-risk carotid plaques and their laterality to stroke in ESUS patient population. We also discuss recurrent stroke events and their laterality to the index stroke.

METHODS

This was a retrospective study. We reviewed data for patients with ESUS between June 20, 2016, and June 20, 2021. Using computed tomography angiography, we analyzed plaque features that are associated with ESUS, and then, we identified the recurrent stroke events and characterized lateralization to the index stroke.

RESULTS

Out of 1779 patients with cryptogenic ischemic stroke, we included 152 patients who met the criteria for ESUS. High-risk plaque features were found more often ipsilateral to the stroke side when compared contralaterally: plaque ulceration (19.08% vs 5.26%, p < .0001), plaque thickness > 3 mm (19.08% vs 7.24%, p = 0.001), and plaque length > 1 cm (13.16% vs 5.92%, p = 0.0218). There was also a significant difference in plaque component in which both components (soft and calcified) and only soft plaques were more prevalent ipsilaterally (42.76% vs 23.68% and 17.76% vs 9.21%, respectively, p < .0001). Of the 152 patients, 17 patients were found to have a recurrent stroke event, and 47% (n = 8) had an ipsilateral stroke to the index event. Moreover, stroke was bilateral in 41% of the patients (n = 7), and contralateral in 12% (n = 2).

CONCLUSION

High-risk plaque features studied here were more prevalent ipsilaterally to the stroke side in ESUS than contralaterally. Multicenter studies are needed to form precise prediction models and scoring systems to help guide treatment, i.e., choice of medical therapy and/or revascularization.

The role of non-stenosing carotid artery plaques in embolic stroke of undetermined source, is it a silent offender? A review of literature

PURPOSE

Atherosclerotic cervical internal carotid artery disease is one of the major causes of ischemic stroke and transient ischemic attacks. The risk of stroke from mild to moderate stenoses (i.e. <50% stenosis) might be underestimated. There is increasing evidence that plaque morphological features reflect plaque instability that may harbor high risk for embolization. In this narrative review, we will review the literature on plaque features that predict vulnerability beyond the degree of stenosis, discuss the clinical association with stroke, and evaluate the evidence that these lesions serve as a source for embolic stroke of unknown source (ESUS).

METHODS

We performed a literature search using PubMed, EMBASE, and Web of Science. The terms "embolic stroke of undetermined source" and "plaque morphology" were used either alone or in combination with "non-flow limiting stenosis," "non-stenosing plaques," "high-risk plaque features" or "internal carotid artery plaque." Data on plaque morphology and ESUS were mainly taken from review articles, observational studies including retrospective cohort and cross-sectional studies, meta-analyses, and systematic reviews.

CONCLUSION

Nonstenosing carotid artery plaques with high-risk features carry a remarkable risk for stroke occurrence and randomized clinical trials are warranted for further evaluation of using carotid artery stenting or carotid endarterectomy to mitigate the risk of stroke.