Carotid Plaque Composition and the Importance of Non-Invasive in Imaging Stroke Prevention

Accuracy of duplex ultrasonography versus angiotomography for the diagnosis of extracranial internal carotid stenosis

INTRODUCTION

Internal carotid artery (ICA) stenosis causes about 15% of ischemic strokes. Duplex ultrasonography (DUS) is the first line of investigation of ICA stenosis, but its accuracy varies in the literature and it is usual to complement the study with another more accurate exam when faced with significant stenosis. There is a lack of studies that compare DUS with angiotomography (CTA) in the present literature.

METHODS

we performed an accuracy study, which compared DUS to CTA of patients in a tertiary hospital with a maximum interval of three months between tests. Patients were selected retrospectively, and two independent and certified vascular surgeons evaluated each image in a masked manner. When there was discordance, a third evaluator was summoned. We evaluated the diagnostic accuracy of ICA stenosis of 50-94% and 70-94%.

RESULTS

we included 45 patients and 84 arteries after inclusion and exclusion criteria applied. For the 50-94% stenosis range, DUS accuracy was 69%, sensitivity 89%, and specificity 63%. For the 70-94% stenosis range, DUS accuracy was 84%, sensitivity 61%, and specificity 93%. There was discordance between CTA evaluators with a change from clinical to surgical management in at least 37.5% of the conflicting reports.

CONCLUSION

DUS had an accuracy of 69% for stenoses of 50-94% and 84% for stenoses of 70-94% of the ICA. The CTA analysis depended directly on the evaluator with a change in clinical conduct in more than 37% of cases.

Associations between carotid plaque shape, biomechanical parameters, and ischemic stroke in mild carotid stenosis with a single plaque

PURPOSE

This cross-sectional cohort-comparison observational study investigated the value of high-frame-rate vector flow (V Flow) imaging for evaluating differences in carotid plaque shape and biomechanical parameters in patients with mild stenosis according to a recent history of ipsilateral ischemic stroke.

METHODS

The present study included 352 patients from February 2023 to October 2023, who were categorized as symptomatic or asymptomatic based on a history of recent ischemic stroke and ipsilateral ischemic lesions detected on head computed tomography or magnetic resonance imaging. A Mindray Resona R9 system was used for B-mode ultrasonography and V Flow imaging. The upstream and downstream surfaces of the plaques were examined at the carotid bifurcation for wall shear stress (WSS), oscillatory shear index (OSI), and turbulence index, which performed peri-plaque biomechanical condition. Multivariable logistic regression models were used to determine associations between plaque shape, V Flow parameters, and ischemic stroke.

RESULTS

Symptomatic patients exhibited higher WSS values for the upstream and downstream surfaces of carotid plaque, as well as higher OSI and turbulence index values for the downstream surface. Type Ⅲ plaques and higher WSS and OSI values for the downstream surface of the plaque were significantly associated with ischemic stroke. Type Ⅲ plaques were more prevalent in symptomatic patients and demonstrated much higher WSS and OSI values for the downstream plaque surface in both groups.

CONCLUSION

High-frame-rate V Flow imaging could assess peri-plaque biomechanical forces and may provide effective imaging biomarkers for early prediction of ischemic stroke in patients with mild stenosis.

Findings of Angiography and Carotid Vessel Wall Imaging Associated with Post-Procedural Clinical Events after Carotid Artery Stenting

PURPOSE

Vessel wall imaging (VWI) for carotid plaque is better for detecting unstable carotid plaque such as intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), and thin/ruptured fibrous cap. However, the role of VWI before carotid artery stenting (CAS) is unclear. Thus, this study aimed to determine the findings of symptomatic carotid stenosis before CAS on angiography and carotid VWI and to evaluate the imaging findings associated with post-procedural clinical events after CAS.

MATERIALS AND METHODS

This retrospective study included 173 consecutive patients who underwent carotid VWI, CAS, and post-procedural diffusion-weighted imaging (DWI) after CAS. Findings of unstable plaque on carotid VWI and unstable findings on angiography were analyzed. We also analyzed the incidence of post-procedural clinical events, any stroke, myocardial infarction (MI), and death within 30 days of CAS.

RESULTS

Of 173 patients, 101 (58.4%) had initial ischemic symptoms and positive findings on DWI. Symptomatic patients were significantly higher in patients with IPH than in patients without IPH (62.4% vs. 45.8%, P=0.031). Degree of stenosis, thrombus of the stenotic lesion, flow delay of internal carotid artery, and flow arrest by filter thrombus had significantly higher prevalence in the symptomatic group. Twenty patients (11.6%) had post-procedural clinical events such as any stroke, clinical symptoms, and/or MI. Hyperlipidemia and intraluminal thrombus on angiography were identified as significant factors influencing post-procedural events after CAS.

CONCLUSION

An intraluminal thrombus on angiography was identified as a significant factor influencing post-procedural clinical events after CAS.

The prevalence of extracranial carotid atherosclerosis detected via ultrasound imaging: A single-centre study in Jeddah, Saudi Arabia

OBJECTIVES

To assess the prevalence of carotid atherosclerosis in Jeddah, Saudi Arabia.

METHODS

Data on patients who underwent carotid ultrasound examinations between 2017-2021 were collected retrospectively from the archive of King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Patient characteristics, blood lipid profiles, and plaque features were extracted from the medical records and ultrasound images. Descriptive data were presented as percentages.

RESULTS

In total, 1334 patients were reviewed. Of these, 13.5% had carotid plaques and were included in the analysis. The mean patient age was 69.8±10.4 years, and 76.1% were men. The prevalence of hypertension was 62.7% and the prevalence of diabetes was 50%, and 7.2% of patients were smokers. Regarding blood lipid profiles, 6.5% of patients had high total cholesterol, 15.1% had high triglyceride levels, and 10.7% had high low-density lipoprotein levels. The median (interquartile range) stenosis was 34.4 (17.2) %, while the median plaque length was 5 (6) mm and thickness was 3 (1) mm. The median carotid intima-media thickness was 1 (0.3) mm. Regarding plaque distribution, 62.7% of plaques were in the carotid bulb. Additionally, 28.3% was in the internal carotid artery, 6.1% was in the common carotid artery, and 2.7% was in the external carotid artery.

CONCLUSION

The prevalence of carotid atherosclerosis among patients in Jeddah, Saudi Arabia, was low. A high prevalence of hypertension and diabetes (≥50%) was observed among the patients. Multicenter studies involving larger Saudi samples are warranted to explore carotid atherosclerosis risk factors.

Association Between Carotid Plaque and Alzheimer's Disease Cerebrospinal Fluid Biomarkers and Cognitive Function in Cognitively Intact Adults: The CABLE Study

Background

The association between carotid plaque and cognitive decline has recently been reported. However, the current research evidence is insufficient, and the possible causes of cognitive changes are unknown.

Objective

This study aims to explore the relationships between carotid plaque and cognition functions, cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers in cognitively intact adults, and try to study the underlying mechanisms.

Methods

We enrolled 165 cognitively normal participants from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study, who had CSF AD biomarker measurements and carotid ultrasound. Linear modeling was used to assess the association of carotid plaque with CSF biomarkers and cognition. Additionally, mediation analysis was conducted through 10,000 bootstrapped iterations to explore potential links between carotid plaque, AD pathology, and cognition.

Results

We found that carotid plaque exhibited significant correlations with Aβ42 (β = -1.173, p = 0.022), Aβ42/Aβ40 (β = -0.092, p < 0.001), P-tau/Aβ42 (β = 0.110, p = 0.045), and T-tau/Aβ42 (β = 0.451, p = 0.010). A significant correlation between carotid plaque and cognition decline was also found in men (β = -0.129, p = 0.021), and mediation analyses revealed that the effect of carotid plaque on cognitive function could be mediated by Aβ42/Aβ40 (proportion of mediation = 55.8%), P-tau/Aβ42 (proportion of mediation = 51.6%, p = 0.015) and T-tau/Aβ42 (proportion of mediation = 43.8%, p = 0.015) mediated.

Conclusions

This study demonstrated the link between carotid plaque and CSF AD biomarkers in cognitively intact adults, and the important role that AD pathology may play in the correlation between carotid plaque and cognitive changes.

Intraplaque Neovascularization, CD68+ and iNOS2+ Macrophage Infiltrate Intensity Are Associated with Atherothrombosis and Intraplaque Hemorrhage in Severe Carotid Atherosclerosis

BACKGROUND

Atherosclerosis is a progressive disease that results from endothelial dysfunction, inflammatory arterial wall disorder and the formation of the atheromatous plaque. This results in carotid artery stenosis and is responsible for atherothrombotic stroke and ischemic injury. Low-grade plaque inflammation determines biological stability and lesion progression.

METHODS

Sixty-seven cases with active perilesional inflammatory cell infiltrate were selected from a larger cohort of patients undergoing carotid endarterectomy. CD68+, iNOS2+ and Arg1+ macrophages and CD31+ endothelial cells were quantified around the atheroma lipid core using digital morphometry, and expression levels were correlated with determinants of instability: ulceration, thrombosis, plaque hemorrhage, calcification patterns and neovessel formation.

RESULTS

Patients with intraplaque hemorrhage had greater CD68+ macrophage infiltration (p = 0.003). In 12 cases where iNOS2 predominated over Arg1 positivity, the occurrence of atherothrombotic events was significantly more frequent (p = 0.046). CD31 expression, representing neovessel formation, correlated positively with atherothrombosis (p = 0.020).

CONCLUSIONS

Intraplaque hemorrhage is often described against the background of an intense inflammatory cell infiltrate. Atherothrombosis is associated with the presence of neovessels and pro-inflammatory macrophages expressing iNOS2. Modulating macrophage polarization may be a successful therapeutic approach to prevent plaque destabilization.

Contrast-Enhanced Ultrasound Feasibility in Assessing Carotid Plaque Vulnerability-Narrative Review

The risk assessment for carotid atherosclerotic lesions involves not only determining the degree of stenosis but also plaque morphology and its composition. Recently, carotid contrast-enhanced ultrasound (CEUS) has gained importance for evaluating vulnerable plaques. This review explores CEUS's utility in detecting carotid plaque surface irregularities and ulcerations as well as intraplaque neovascularization and its alignment with histology. Initial indications suggest that CEUS might have the potential to anticipate cerebrovascular incidents. Nevertheless, there is a need for extensive, multicenter prospective studies that explore the relationships between CEUS observations and patient clinical outcomes in cases of carotid atherosclerotic disease.

Novel Imaging-Based Biomarkers for Identifying Carotid Plaque Vulnerability

Carotid artery disease has traditionally been assessed based on the degree of luminal narrowing. However, this approach, which solely relies on carotid stenosis, is currently being questioned with regard to modern risk stratification approaches. Recent guidelines have introduced the concept of the "vulnerable plaque," emphasizing specific features such as thin fibrous caps, large lipid cores, intraplaque hemorrhage, plaque rupture, macrophage infiltration, and neovascularization. In this context, imaging-based biomarkers have emerged as valuable tools for identifying higher-risk patients. Non-invasive imaging modalities and intravascular techniques, including ultrasound, computed tomography, magnetic resonance imaging, intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have played pivotal roles in characterizing and detecting unstable carotid plaques. The aim of this review is to provide an overview of the evolving understanding of carotid artery disease and highlight the significance of imaging techniques in assessing plaque vulnerability and informing clinical decision-making.

MR Imaging of Carotid Artery Atherosclerosis: Updated Evidence on High-Risk Plaque Features and Emerging Trends

MR imaging is well-established as the criterion standard for carotid artery atherosclerosis imaging. The capability of MR imaging to differentiate numerous plaque components has been demonstrated, including those features that are associated with a high risk of sudden changes, thrombosis, or embolization. The field of carotid plaque MR imaging is constantly evolving, with continued insight into the imaging appearance and implications of various vulnerable plaque characteristics. This article will review the most up-to-date knowledge of these high-risk plaque features on MR imaging and will delve into 2 major emerging topics: the role of vulnerable plaques in cryptogenic strokes and the potential use of MR imaging to modify carotid endarterectomy treatment guidelines.

Duplex ultrasound for surveillance of lower limb revascularisation

BACKGROUND

Lower extremity atherosclerotic disease (LEAD) - also known as peripheral arterial disease - refers to the obstruction or narrowing of the large arteries of the lower limbs, most commonly caused by atheromatous plaque. Although in many cases of less severe disease patients can be asymptomatic, the major clinical manifestations of LEAD are intermittent claudication (IC) and critical limb ischaemia, also known as chronic limb-threatening ischaemia (CLTI). Revascularisation procedures including angioplasty, stenting, and bypass grafting may be required for those in whom the disease is severe or does not improve with non-surgical interventions. Maintaining vessel patency after revascularisation remains a challenge for vascular surgeons, since approximately 30% of vein grafts may present with restenosis in the first year due to myointimal hyperplasia. Restenosis can also occur after angioplasty and stenting. Restenosis and occlusions that occur more than two years after the procedure are generally related to progression of the atherosclerosis. Surveillance programmes with duplex ultrasound (DUS) scanning as part of postoperative care may facilitate early diagnosis of restenosis and help avoid amputation in people who have undergone revascularisation.

OBJECTIVES

To assess the effects of DUS versus pulse palpation, arterial pressure index, angiography, or any combination of these, for surveillance of lower limb revascularisation in people with LEAD.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and LILACS databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 1 February 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared DUS surveillance after lower limb revascularisation versus clinical surveillance characterised by medical examination with pulse palpation, with or without any other objective test, such as arterial pressure index measures (e.g. ankle-brachial index (ABI) or toe brachial index (TBI)). Our primary outcomes were limb salvage rate, vessel or graft secondary patency, and adverse events resulting from DUS surveillance. Secondary outcomes were all-cause mortality, functional walking ability assessed by walking distance, clinical severity scales, quality of life (QoL), re-intervention rates, and functional walking ability assessed by any validated walking impairment questionnaire. We presented the outcomes at two time points: two years or less after the original revascularisation (short term) and more than two years after the original revascularisation (long term).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We used the Cochrane RoB 1 tool to assess the risk of bias for RCTs and GRADE to assess the certainty of evidence. We performed meta-analysis when appropriate.

MAIN RESULTS

We included three studies (1092 participants) that compared DUS plus pulse palpation and arterial pressure index (ABI or TBI) versus pulse palpation and arterial pressure index (ABI or TBI) for surveillance of lower limb revascularisation with bypass. One study each was conducted in Sweden and Finland, and the third study was conducted in the UK and Europe. The studies did not report adverse events resulting from DUS surveillance, functional walking ability, or clinical severity scales. No study assessed surveillance with DUS scanning after angioplasty or stenting, or both. We downgraded the certainty of evidence for risk of bias and imprecision. Duplex ultrasound plus pulse palpation and arterial pressure index (ABI or TBI) versus pulse palpation plus arterial pressure index (ABI or TBI) (short-term time point) In the short term, DUS surveillance may lead to little or no difference in limb salvage rate (risk ratio (RR) 0.84, 95% confidence interval (CI) 0.49 to 1.45; I² = 93%; 2 studies, 936 participants; low-certainty evidence) and vein graft secondary patency (RR 0.92, 95% CI 0.67 to 1.26; I² = 57%; 3 studies, 1092 participants; low-certainty evidence). DUS may lead to little or no difference in all-cause mortality (RR 1.11, 95% CI 0.70 to 1.74; 1 study, 594 participants; low-certainty evidence). There was no clear difference in QoL as assessed by the 36-item Short Form Health Survey (SF-36) physical score (mean difference (MD) 2 higher, 95% CI 2.59 lower to 6.59 higher; 1 study, 594 participants; low-certainty evidence); the SF-36 mental score (MD 3 higher, 95% CI 0.38 lower to 6.38 higher; 1 study, 594 participants; low-certainty evidence); or the EQ-5D utility score (MD 0.02 higher, 95% CI 0.03 lower to 0.07 higher; 1 study, 594 participants; low-certainty evidence). DUS may increase re-intervention rates when considered any therapeutic intervention (RR 1.38, 95% CI 1.05 to 1.81; 3 studies, 1092 participants; low-certainty evidence) or angiogram procedures (RR 1.53, 95% CI 1.12 to 2.08; 3 studies, 1092 participants; low-certainty evidence). Duplex ultrasound plus pulse palpation and arterial pressure index (ABI or TBI) versus pulse palpation plus arterial pressure index (ABI or TBI) (long-term time point) One study reported data after two years, but provided only vessel or graft secondary patency data. DUS may lead to little or no difference in vessel or graft secondary patency (RR 0.83, 95% CI 0.19 to 3.51; 1 study, 156 participants; low-certainty evidence). Other outcomes of interest were not reported at the long-term time point.

AUTHORS' CONCLUSIONS

Based on low certainty evidence, we found no clear difference between DUS and standard surveillance in preventing limb amputation, morbidity, and mortality after lower limb revascularisation. We found no studies on DUS surveillance after angioplasty or stenting (or both), only studies on bypass grafting. High-quality RCTs should be performed to better inform the best medical surveillance of lower limb revascularisation that may reduce the burden of peripheral arterial disease.

Carotid massive intraplaque hemorrhage, lipid-rich necrotic core, and heavy circumferential calcification were associated with new ipsilateral ischemic cerebral lesions after carotid artery stenting: high-resolution magnetic resonance vessel wall imaging study

Background

Following carotid artery stenting (CAS), new ipsilateral ischemic lesions (NIILs) in the brain are frequently seen using diffusion-weighted imaging (DWI). This study's goal was to identify the imaging characteristics associated with NIILs after CAS by high-resolution magnetic resonance vessel wall imaging (HR-VWI).

Methods

This was a case-control study. 109 patients who received CAS for atherosclerotic carotid stenosis were retrospectively collected and categorized into NIILs positive and NIILs negative groups. Based on the existence or absence of stroke symptoms after CAS, the NIILs positive group was split into two subgroups: the NIILs symptomatic group and the NIILs asymptomatic group. Patients underwent preoperative HR-VWI and brain magnetic resonance imaging (MRI) within 7 days preoperatively and within 3 days postoperatively. Quantitatively assess carotid plaque burden and components using HR-VWI. The baseline and HR-VWI imaging characteristics of all patients were retrospectively analyzed. To ascertain the imaging characteristics connected with NIILs after CAS, logistic regression analysis was carried out.

Results

Among 109 patients, 38 patients (34.9%) developed NIILs after CAS. Six patients (5.5%) developed symptomatic stroke with NIILs. The logistic regression analysis revealed that maximum wall thickness (Max WT) [odds ratio (OR), 1.53; 95% confidence interval (CI): 1.20-1.96; P=0.001], the maximum area percentage of lipid-rich necrotic core (LRNC) (OR, 1.05; 95% CI: 1.03-1.07; P<0.001), the volume of LRNC (OR, 1.004; 95% CI: 1.002-1.005; P<0.001), the maximum area percentage of intraplaque hemorrhage (IPH) (OR, 1.17; 95% CI: 1.11-1.24; P<0.001), the volume of IPH (OR, 1.06; 95% CI: 1.03-1.08; P<0.001), and maximum circumference score of calcification in a single slice (OR, 1.66; 95% CI: 1.04-2.63; P=0.03) were linked with NIILs following CAS.

Conclusions

The massive IPH, LRNC, and heavy circumferential calcification were associated with NIILs after CAS. Preoperative quantitative assessment of carotid plaque using HR-VWI may be useful for predicting NIILs following CAS.

microRNAs Associated with Carotid Plaque Development and Vulnerability: The Clinician's Perspective

Ischemic stroke (IS) related to atherosclerosis of large arteries is one of the leading causes of mortality and disability in developed countries. Atherosclerotic internal carotid artery stenosis (ICAS) contributes to 20% of all cerebral ischemia cases. Nowadays, atherosclerosis prevention and treatment measures aim at controlling the atherosclerosis risk factors, or at the interventional (surgical or endovascular) management of mature occlusive lesions. There is a definite lack of the established circulating biomarkers which, once modulated, could prevent development of atherosclerosis, and consequently prevent the carotid-artery-related IS. Recent studies emphasize that microRNA (miRNA) are the emerging particles that could potentially play a pivotal role in this approach. There are some research studies on the association between the expression of small non-coding microRNAs with a carotid plaque development and vulnerability. However, the data remain inconsistent. In addition, all major studies on carotid atherosclerotic plaque were conducted on cell culture or animal models; very few were conducted on humans, whereas the accumulating evidence demonstrates that it cannot be automatically extrapolated to processes in humans. Therefore, this paper aims to review the current knowledge on how miRNA participate in the process of carotid plaque formation and rupture, as well as stroke occurrence. We discuss potential target miRNA that could be used as a prognostic or therapeutic tool.