Carotid Imaging Research Articles

Carotid plaque magnetic resonance imaging and recurrent stroke risk: A systematic review and meta-analysis.

Background:MRI findings of carotid plaque components have been studied recently as a tool to predict recurrent ischemic events. We performed a systematic review and meta-analysis to summarize the association of MRI-determined intraplaque hemorrhage, lipid-rich necrotic core, and thinning/rupture of the fibrous cap with recurrent ischemic events.Methods:Electronic search was performed in PUBMED, EMBASE, Cochrane Controlled Register of Trials (CENTRAL) from inception to Oct 30, 2018. We included cohort studies with an average follow-up time of more than 1 month in which intraplaque hemorrhage, lipid-rich necrotic core, or thinning/rupture of the fibrous cap were associated with recurrent ipsilateral stroke or ischemic events. We performed heterogeneity assessment before carrying out meta-analysis. According to the heterogeneity, we selected fixed-effect model for meta-analysis of the included cohort studies.Results:Using a prespecified search strategy, of the 2128 articles, 6 studies with a total number of 621 participants met eligibility for systematic review and meta-analysis. The hazard ratios of intra-plaque hemorrhage, thinning/rupture of the fibrous cap and lipid rich necrotic core as recurrent Stroke/Transient ischemic attack (TIA) were 7.14(95% confidence interval, 4.32 to 11.82), 5.68(95% confidence interval, 2.40 to 13.47), and 2.73(95% confidence interval, 1.04 to 7.16), respectively. No significant heterogeneity was found in the 3 meta-analyses.Conclusions:The presence of intraplaque hemorrhage, lipid-rich necrotic core, and thinning/rupture of the fibrous cap on MRI of carotid plaque are strong predictors of recurrent stroke events. However, due to the lack of original studies, larger cohort studies are warranted.

Clinical Value of the Carotid Ultrasound in Evaluation of Plaque Composition as Compared to the Carotid MRI

Abstract Background: The main aim of carotid imaging studies is the assessment of the carotid plaque morphology with the detection of vulnerable plaques which is associated with increased risk of cerebrovascular insult, hence proper deline-ation of plaque composition is a crucial step for further management of brain ischemic insult. Aim of Study: To define the inter method agreement between the carotid ultrasound and carotid MRI for charac-terization of vulnerable plaques with further assessment of carotid ultrasound sensitivity and specificity. Material and Methods: The study was conducted over 60 patients. The modified G-W classification was used to assess the sonographic features of the carotid plaques, and compared with the plaque composition using carotid MRI. Results: Our study included 60 patients, their ages ranged between 53 and 78 years with a mean age of 60.3±9.8 years. 56.7% of patients was male. The agreement between carotid ultrasound and carotid MRI was good with k=0.734, sensitivity of the carotid ultrasound to detect the vulnerable plaque was 88.1% with an overall accuracy of 88.3%. Conclusion: The carotid ultrasound examination is con-sidered the first-line modality for assessment of the carotid plaque composition, with good agreement with carotid MRI and acceptable sensitivity and accuracy for characterization of vulnerable plaques.

Gadolinium Enhancement of the Aneurysm Wall in Extracranial Carotid Artery Aneurysms.

The natural history and optimal treatment of extracranial carotid artery aneurysms are unknown. Gadolinium enhancement of the aneurysm wall may reflect aneurysm wall inflammation and instability. In this study, we investigated the feasibility of extracranial carotid artery aneurysm wall imaging and explored a potential relationship of aneurysm wall enhancement with aneurysm growth and the presence of (silent) brain infarcts and white matter lesions. Fourteen conservatively treated patients with 15 asymptomatic extracranial carotid artery aneurysms underwent gadolinium-enhanced 3T MR imaging at 2 time points with a 12-month interval. Primary outcome was growth of the aneurysm sac (≥2.0 mm); secondary outcomes were the presence of (silent) brain infarcts and white matter lesions at baseline and follow-up. MR images were reviewed by 2 independent observers, and inter- and intraobserver reproducibility was assessed. Seven (50%) patients were men; the median age was 55 years (range, 40-69 years). Eleven extracranial carotid artery aneurysms (73%) were saccular (median size, 11 mm; range, 5.0-38.5 mm), and 4 were fusiform (median size, 21.5 mm; range, 10.0-40.0 mm). Eleven of 15 aneurysms (73%) exhibited gadolinium enhancement at baseline. Four aneurysms (27%) showed growth at follow-up imaging, 2 gadolinium-positive (+) and 2 gadolinium-negative (-) (P = .245). Three patients (21%) had ipsilateral brain infarcts at baseline; 1 of them showed a new silent brain infarct at follow-up imaging (gadolinium+). Nine patients (64%) showed bilateral white matter lesions at baseline. In 3 patients, increased white matter lesion severity was observed at follow-up (2 gadolinium+). All observations showed excellent inter- and intraobserver reproducibility. In this explorative study, we demonstrated that extracranial carotid artery aneurysm wall imaging was feasible. Future well-powered studies are needed to investigate whether extracranial carotid artery aneurysm gadolinium enhancement predicts aneurysm growth and thromboembolic complications.

A flexible five-channel shielded-coaxial-cable (SCC) transceive neck coil for high-resolution carotid imaging at 7T.

PurposeImaging the carotid arteries at 7T ideally requires a flexible multichannel array that allows B1‐shimming and conforms to different neck sizes. The major challenge is to minimize coupling between closely spaced coils and to make the coupling relatively insensitive to loading conditions.MethodsWe have designed a five‐channel flexible transceive array composed of shielded‐coaxial‐cable coils placed on the anterior part of the neck and conforming to the anatomy. In vivo imaging of the carotid arteries in three subjects has been performed.ResultsThe measured noise correlation matrices show the decoupling level between the individual elements to be −12.5 dB and better. Anatomical localizer imaging of the carotids shows both carotids in every subject well visualized after B1‐shimming. In vivo black‐blood, carotid images were acquired with very high in‐plane spatial resolution (0.25 × 0.25 mm2) with clear depiction of the vessel walls.ConclusionsThe flexibility of the proposed coil has been demonstrated by imaging subjects with different neck circumferences. To the best of our knowledge, the in‐plane resolution of 0.25 × 0.25 mm2 is the highest reported at 7T.

Ferumoxytol-enhanced three-dimensional magnetic resonance imaging of carotid atheroma- a feasibility and temporal dependence study

Ferumoxytol is an ultrasmall super paramagnetic particles of iron oxide (USPIO) agent recently used for magnetic resonance (MR) vascular imaging. Other USPIOs have been previously used for assessing inflammation within atheroma. We aim to assess feasibility of ferumoxytol in imaging carotid atheroma (with histological assessment); and the optimum MR imaging time to detect maximum quantitative signal change post-ferumoxytol infusion. Ten patients with carotid artery disease underwent high-resolution MR imaging of their carotid arteries on a 1.5 T MR system. MR imaging was performed before and at 24, 48, 72 and 96 hrs post ferumoxytol infusion. Optimal ferumoxytol uptake time was evaluated by quantitative relaxometry maps indicating the difference in T2* (ΔT2*) and T2 (ΔT2) between baseline and post-Ferumoxytol MR imaging using 3D DANTE MEFGRE qT2*w and iMSDE black-blood qT2w sequences respectively. 20 patients in total (10 symptomatic and 10 with asymptomatic carotid artery disease) had ferumoxytol-enhanced MR imaging at the optimal imaging window. 69 carotid MR imaging studies were completed. Ferumoxytol uptake (determined by a decrease in ΔT2* and ΔT2) was identified in all carotid plaques (symptomatic and asymptomatic). Maximum quantitative decrease in ΔT2* (10.4 [3.5–16.2] ms, p < 0.001) and ΔT2 (13.4 [6.2–18.9] ms; p = 0.001) was found on carotid MR imaging at 48 hrs following the ferumoxytol infusion. Ferumoxytol uptake by carotid plaques was assessed by histopathological analysis of excised atheroma. Ferumoxytol-enhanced MR imaging using quantitative 3D MR pulse sequences allows assessment of inflammation within carotid atheroma in symptomatic and asymptomatic patients. The optimum MR imaging time for carotid atheroma is 48 hrs after its administration.

Comparative Analysis of Atherosclerotic Disease in the Carotid and Femoral Arteries

K Hurst1, R Choudhury2, A Handa1&#x0D; 1. Nuffield Department of Surgical Sciences, University of Oxford&#x0D; 2. Radcliffe Department of Medicine, University of Oxford&#x0D; Introduction &#x0D; The outcomes for patients with PAOD have remained unchanged for over 25 years, whereas primary prevention has made a marked difference to the incidence of stroke and MI. Why is treatment more effective for certain types of atherosclerotic plaques than others? Why do certain patients experience a stroke but never an amputation?&#x0D; Methods&#x0D; The study aims to use in vivo and ex vivo analysis of carotid and femoral atherosclerotic plaque from patients enrolled in the OxPVD study. Each participant will undergo pre-operative in vivo carotid and femoral vessel (ipsilateral) imaging using T1/T2 weighted MRI; inclusive of plaque, and ex vivo plaque analysis using micro CT, micro MRI and histological staining. Comparative analysis of the carotid versus femoral plaques will be completed using above techniques. &#x0D; Results&#x0D; Primary results from this study have shown that novel MRI DANTE sequences can successfully characterise femoral atherosclerotic plaque in vivo. Using micro CT and mass spectrometry techniques from micro MRI, we have further quantified the differences in composition of carotid and femoral disease. Finally, histological staining has implied that the disease processes behind femoral and carotid atherosclerosis may be different; with carotid narrowing by fat infiltration and statistically significant reduction in nuclei, compared to femoral plaque showing intra luminal calcium deposition without intimal destruction.&#x0D; Conclusion&#x0D; These preliminary results are beginning to highlight the key compositional differences between carotid and femoral atherosclerosis, and with these results it may be possible to trial different therapeutic targets, particularly in the context of PAOD.

Abstract WP452: Nurses Use Real-Time Patient Identification Tool to Improve Care Coordination for Transient Ischemic Attack Patients

Background: Programs emphasizing early evaluation and management have reduced 70% of transient ischemic attack (TIA) patients’ recurrent events. One barrier to guideline-concordant care is inadequate care coordination. Purpose: Our objective was to evaluate adoption of nurse care coordination programs on TIA care quality at two Veteran Health Administration (VHA) facilities. Methods: Nurse care coordination programs with real-time patient identification and using Consolidated Framework for Implementation Research (CFIR) to guide local adoption, were evaluated at 2 VHA facilities. Programs were coordinated by an Emergency Department (ED) Nurse Navigator or Neurology Stroke Nurse Coordinator. The nurses used a Patient Identification Tool which was updated daily and displayed: TIA patient’s name, event and discharge dates, diagnosis, visit type (ED or inpatient), and primary care team. Nurses reviewed patients’ charts for key care components (e.g., medications), identified gaps in care, and provided follow-up. TIA care quality was evaluated by Without Fail Rate (WFR) which describes the facility-level proportion of patients who received all eligible processes of care (anticoagulation for atrial fibrillation, antithrombotics, brain imaging, carotid artery imaging, hypertension control, moderate/high intensity statin, neurology consultation). Results: We compared the WFR before (Fiscal Year [FY] 2017) and after (FY2019) implementation of the care coordination programs: Site-1, 59.6% (N=48) to 71.4% (N=30), p=0.332 (not significant); Site-2, 15.9% (N=47) to 38.5% (N=29), p=0.045 (significant). The individual process of care with greatest improvement was high/moderate potency statin at Site-1 (68.4% to 82.6%, p=0.250 [not significant]) and neurology consultation at Site-2 (39.5% to 80.8%, p=0.001 [significant]). Conclusions: Nurse care coordination programs using real-time patient identification were associated with improved quality of care. These broadly generalizable programs were important components of a comprehensive, multidisciplinary quality improvement initiative. Healthcare systems interested in improving care for TIA patients may find real-time patient identification useful in coordinating their care.

Abstract WP347: The Effectiveness and Implementation of the Protocol-Guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) Quality Improvement Program: An Exampleofa Learning Healthcare System in Action

Objectives: Transient ischemic attack (TIA) patients are at high risk of recurrent vascular events; timely management can reduce that risk by 70%. The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurological Symptoms (PREVENT) trial evaluated the implementation of a quality improvement (QI) program aligned with Learning Healthcare System principles to improve TIA care. Methods: A facility-based, stepped-wedge trial was conducted at six diverse sites. The intervention included five components: clinical programs, data feedback, professional education, electronic health record tools, and QI support. Implementation strategies included: team activation via audit and feedback, goal setting, reflecting and evaluating, and planning; external facilitation; and building a community of practice. The primary effectiveness outcome was the Without Fail rate (WFR); proportion of TIA patients who received all processes of care for which they were eligible among: brain imaging, carotid artery imaging, neurology consultation, hypertension control, anticoagulation for atrial fibrillation, antithrombotics, high/moderate potency statins. The primary implementation outcomes were the number of improvement activities completed and the Group Organization (GO) scores for providing and improving care (scale of 1-10). Results: The 6 PREVENT facilities cared for N=162 control period TIA patients and N=191 intervention period TIA patients. The mean facility WFR increased from 36.7% (baseline) to 53.9% (active implementation); p=0.002 (adjusted for temporal trend, hospital admission). The mean number of improvement activities completed during the 1-year implementation period was 26 (range 11-39). The mean facility GO scores increased: providing care, 1.2 to 6.5; improving care, 1.0 to 6.7. Conclusions: PREVENT advances three aspects of a learning healthcare system: Learning from Data (teams interacted with their facility’s performance data to explore hypotheses, plan QI activities, and evaluate change over time); Learning from Each Other (teams participated in monthly virtual collaborative conferences), and Sharing Best Practices (teams shared tools and protocols).

Abstract WP272: Automatic Detection and Measurement of Atherosclerotic Plaques in Carotid Ultrasound Using Deep Learning

Purpose: B-Mode ultrasound imaging is commonly used for detection and measurement of atherosclerotic carotid plaques, which are an important cause of ischemic stroke. However, accurate interpretation of ultrasound can be difficult and subjective. Artificial Intelligence (AI) models can assist in image interpretation, reducing subjectivity, and speeding up the process of detection and measurement of carotid plaques. We evaluated the accuracy of a deep learning model for automatic detection of carotid plaques in b-mode ultrasound compared against expert interpretation of the images. Methods: We propose an automated method using convolutional neural networks to detect atherosclerotic plaques and measure intima-media thickness (IMT) in B-Mode carotid images. In contrast to most of the existing methods, our goal was to not only measure IMT in healthy subjects (max IMT below 1.2 mm) but also to provide accurate detection of plaques and other vessel wall pathology. Given the B-mode longitudinal image as the input, the neural network first finds a region of interest (ROI) surrounding the artery and then segments both near wall and far wall of the artery. The network was trained and tested on two separate datasets obtained retrospectively from 3 stroke centers and 4 different ultrasound machine manufacturers. The training dataset was comprised of 1021 images. Results: The performance of the method was assessed on an independent dataset not used for model development to prevent bias, consisting of 205 images, where 54% (111 out of 205) of the images had pathology. The ground truth was determined by an expert reader interpreting images, and Pearson coefficient (IMT correlation) and Bland-Altman analysis were used to assess the performance of the method. The obtained correlation coefficient was 0.93 and r-squared was 0.87, showing a strong correlation. There was no significant over or under estimation of IMT (bias = -0.002 mm, lower limit of agreement (LOA) = -0.246 mm, upper LOA = 0.242 mm). Conclusion: The results show that the proposed deep learning method can be used for accurate analysis and interpretation of carotid ultrasound scans in a clinical setting and potentially reduce the reporting time while increasing objectivity of the reports.

Co-prevalence of extracranial carotid aneurysms differs between European intracranial aneurysm cohorts.

Background and purposePreviously, we showed that co-prevalence of extracranial carotid artery aneurysms (ECAAs) in patients with intracranial aneurysms (IAs) was 2% in a Dutch cohort. In order to obtain more precise estimates and discover potential predictors of ECAA co-prevalence in the European population, we retrospectively compared differences and similarities of our Dutch cohort with a Finnish cohort using protocolled imaging of the cerebrovascular tree.MethodsIA patients within the prospective database of the Kuopio University Hospital were eligible for this study (n = 1,118). Image analysis and hospital chart review were conducted.ResultsIn total, 458 patients with complete carotid imaging conform protocol were analyzed. Twenty-four ECAAs in 21 patients were identified (4.6%, 95% CI 2.9–6.9), a higher co-prevalence than in the Dutch cohort (1.9%; 95% CI 1.0–3.3), prevalence odds ratio (POR) 2.45 (95% CI 1.19–5.03). In the Finnish cohort, 25% of all ECAAs were located around the carotid bifurcation, others in the internal carotid artery distally from the bifurcation. Independent predictors for ECAA co-prevalence were origin of country (POR 2.41, 95% CI 1.15–5.06) and male gender (POR 2.25, 95% CI 1.09–4.64).ConclusionThe co-prevalence of ECAA in IA patients was twice as high in the Finnish compared to the Dutch IA cohort, with origin of country and male gender as independent predictors. Twenty-five percent of ECAAs would be missed, if the carotid bifurcation was not imaged. Therefore, we propose to always include imaging of the carotid bifurcation as the gold standard technique to identify ECAA in IA patients.

The asymptomatic octogenarian and carotid endarterectomy—While we await the results of CREST-2

Currently there is no definitive level I evidence regarding the appropriate management of asymptomatic moderate to severe carotid artery stenosis in the octogenarian patient. In this 5-year review of National Surgical Quality Improvement Program registry data, exceptional “real-world” results are reported with use of carotid endarterectomy (CEA) in this growing cohort.1Glousman B.N. Sebastian R. Macsata R. Kuang X. Yang A. Patel D. et al.Carotid endarterectomy for asymptomatic carotid stenosis is safe in octogenarians.J Vasc Surg. 2020; 71: 518-524Abstract Full Text Full Text PDF PubMed Scopus (8) Google Scholar The combined stroke and death rate was 2% at 30-day follow-up (stroke rate 1%!), with the authors stating that “age alone should not interdict this modality.” As the authors acknowledge, the most notable limitations of this study are the significant preoperative selection bias apparent in the octogenarians undergoing CEA and the considerably larger number of younger patients studied (nearly five times more) than octogenarians. Other factors include that approximately 25% of all of the study subjects were treated with CEA for only 50% to 79% carotid stenosis, lack of use of standard preoperative carotid imaging or grading criteria for selection to undergo CEA, 30-day follow-up only, and absence of data regarding preoperative cardiovascular risk stratification to determine fitness for surgery. Despite the noted limitations of the database used, the authors have demonstrated that with proper selection and execution, results with use of CEA in the fit octogenarian with asymptomatic carotid artery stenosis can be equivalent to those obtained in younger patients. Whereas this is clearly not level I evidence, it does again confirm that properly applied CEA remains an extremely safe and efficacious treatment modality even in octogenarians. The opinions or views expressed in this commentary are those of the author and do not necessarily reflect the opinions or recommendations of the Journal of Vascular Surgery or the Society for Vascular Surgery. Carotid endarterectomy for asymptomatic carotid stenosis is safe in octogenariansJournal of Vascular SurgeryVol. 71Issue 2PreviewCarotid endarterectomy (CEA) is the gold standard to prevent a recurrent stroke in symptomatic patients with carotid stenosis. However, in the modern era, the benefit of CEA in asymptomatic octogenarian patients has come into question. This study investigates real-world outcomes of CEA in asymptomatic octogenarians. Full-Text PDF

Carotid artery ultrasound image analysis: A review of the literature.

Stroke is one of the prominent causes of death in the recent days. The existence of susceptible plaque in the carotid artery can be used in ascertaining the possibilities of cardiovascular diseases and long-term disabilities. The imaging modality used for early screening of the disease is B-mode ultrasound image of the person in the artery area. The objective of this article is to give a widespread review of the imaging modes and methods used for studying the carotid artery for identifying stroke, atherosclerosis and related cardiovascular diseases. We encompass the review in methods used for artery wall tracking, intima-media, and lumen segmentation which will help in finding the extent of the disease. Due to the characteristics of the imaging modality used, the images have speckle noise which worsens the image quality. Adaptive homomorphic filtering with wavelet and contourlet transforms, Levy Shrink, gamma distribution were used for image denoising. Learning-based neural network approaches for denoising give better edge preservation. Domain knowledge-based segmentation approaches have proved to provide more accurate intima-media thickness measurements. There is a requirement of useful fully automatic segmentation approaches, 3D, 4D systems, and plaque motion analysis. Taking into consideration the image priors like geometry, imaging physics, intensity and temporal data, image analysis has to be performed. Encouragingly more research has focused on content-specific segmentation and classification techniques. With the evaluation of machine learning algorithms, classifying the image as with or without a fat deposit has gained better accuracy and sensitivity. Machine learning-based approaches like self-organizing map, k-nearest neighborhood and support vector machine achieve promising accuracy and sensitivity in classification. The literature reveals that there is more scope in identifying a patient-specific model in a fully automatic manner.

Characterization of Carotid Atherosclerotic Plaques Using 3-Dimensional MERGE Magnetic Resonance Imaging and Correlation With Stroke Risk Factors.

Background and Purpose- High-resolution magnetic resonance imaging is capable of characterizing carotid atherosclerotic plaque morphology and composition. Most reported carotid plaque imaging techniques are 2-dimensional (2D) based with limited longitudinal coverage of ≈30 mm, which may be insufficient for complete visualization of extracranial carotid atheroma. A 3D black-blood imaging technique, motion-sensitized driven equilibrium prepared rapid gradient echo technique (3D-MERGE) can provide larger coverage. We sought to use 3D-MERGE to investigate carotid atherosclerosis plaque distribution and to analyze their correlation with clinical information and stroke risk factors. Methods- From 5 hospitals in China, 97 subjects suspected of recent stroke or transient ischemic attack were imaged with 3D-MERGE within 2 weeks of symptoms using 3T magnetic resonance imaging. Images were analyzed by 2 reviewers. Plaque length was calculated and categorized as plaques within, partially outside, or completely outside of typical 2D magnetic resonance imaging coverage. Associations between plaque features and clinical information, stroke risk factors were assessed. Results- Ninety-seven subjects with 194 carotid arteries (70 men and 27 women, mean age 60 years) were analyzed. Of the 136 plaques identified, 68 (50%) were within, 46 (33.8%) were partially outside, and 22 (16.2%) were completely outside of 2D magnetic resonance imaging coverage. Total plaque length was significantly positively associated with male sex (P<0.001), hypertension (P=0.011), and history of smoking (P<0.001). Hypertensive subjects were more likely to have at least one plaque completely outside the 2D magnetic resonance imaging coverage than nonhypertensive subjects (P=0.007). Conclusions- The 3D-MERGE allows for the identification of substantially more carotid plaques than 2D black-blood techniques. The extent and distribution of plaque, identified by the larger coverage afforded by 3D-MERGE, were found to correlate significantly with male sex and risk factors that are common among patients with stroke, including hypertension and history of cigarette smoking.

The progression of carotid atherosclerosis and imaging markers of dementia.

IntroductionWe studied the association of carotid intima‐media thickness (CIMT) with hippocampal volume (HV) in community dwelling individuals, testing the hypothesis that persons with carotid atherosclerosis progression would have lower HV.MethodsWe studied 1376 Framingham Offspring participants with two carotid ultrasounds and brain magnetic resonance imaging (MRIs). We used multivariable linear regression analyses to relate CIMT progression and HV and total brain volume. Regression models were adjusted for demographics and vascular risk factors, time interval between imaging examinations, and baseline CIMT. We assessed effect modification by hypertension treatment (HRx).ResultsParticipants with higher ICA IMT progression had significantly lower HV after adjustment for vascular risk factors and baseline IMT (standardized beta ± standard error: −0.067 ± 0.027, P = .01). We observed weaker association between ICA IMT change and HV among subjects treated for hypertension (β = −0.047, P = .19 vs β = −0.096, P = .026).DiscussionCumulative vascular risk factor exposure, reflected by CIMT progression, may increase the risk of neurodegeneration.

Carotid Plaque Morphology is Similar in Patients with Reduced and Normal Renal Function.

Background:Chronic Kidney Disease (CKD) is associated with an increased risk for cardiovascular events such as stroke. However, it is still unclear if decreased kidney function is associated with a vulnerable atherosclerotic plaque phenotype. To explore if renal function was associated with carotid plaque vulnerability we analyzed carotid plaques obtained at surgery from the Carotid Plaque Imaging Project (CPIP).Methods:Patients were enrolled through the CPIP cohort. The indication for surgery was plaques with stenosis >70%, associated with ipsilateral symptoms or plaques with stenosis >80% not associated with symptoms. Transversal sections from the most stenotic plaque region were analyzed for connective tissue, calcium, lipids, macrophages, intraplaque hemorrhage, and smooth muscle cells. Homogenates were analyzed for collagen and elastin.Results:Carotid endarterectomy specimens from 379 patients were obtained. The median GFR was 73 ml/min/1.73 m2. Plaque characteristics showed no significant association with eGFR, neither when eGFR was divided in CKD groups nor when eGFR was handled as a continuous variable and adjusting for other known risk factors (ie, age, diabetes, hypertension, and smoking).Conclusions:The higher risk of cardiovascular disease such as stroke in CKD is not associated with increased plaque vulnerability and other factors have to be sought.

The Determination of the Plaque Burden on the Carotid Artery With Ultrasound Significantly Improves the Risk Prediction in Middle-Aged Subjects Compared to PROCAM: An Outcome Study.

BackgroundThere are only few data about the predictive value of atherosclerosis imaging beyond traditional risk calculators in younger subjects.MethodsWe assessed cardiovascular risk prediction with the PROCAM (the Prospective Cardiovascular Munster Study) risk equation and with carotid plaque imaging (determination of total plaque area (TPA) and the maximum plaque thickness with ultrasound) in subjects without known cardiovascular diseases. The follow-up was generated during follow-up examinations as part of preventive medical examinations or by telephone calls.ResultsIn 2,508 subjects aged 35 - 64 years (50 ± 8 years, 34% women), 132 (5.3%) cardiovascular events occurred (42 myocardial infarction, 17 bypass surgery, 31 stent implantation, 42 coronary artery disease defined by invasive angiography) during a mean follow-up period of 5.4 (1 - 12) years. TPA in combination with the maximum plaque thickness (type III - IV b plaques ) tended to be superior compared to TPA, and both plaque imaging methods were superior to PROCAM: area under the curve (AUC) 0.9 (95% confidence interval (CI): 0.91 - 0.89) vs. 0.89 (95% CI: 0.90 - 0.88), P = 0.2 vs. 0.82 (95% CI: 0.84 - 0.81), P = 0.001; positive predictive value (PPV) 27% (95% CI: 0.31 - 0.22) vs. 19% (95% CI: 0.22 - 0.16) vs.19% (95% CI: 0.27 - 0.13).ConclusionsAmount of carotid plaque assessed by carotid plaque imaging significantly improves cardiovascular risk prediction beyond the PROCAM risk equation.

1681 Carotid screening prior to stress echocardiography, an opportunity to assess cardiovascular risk?

Abstract BACKGROUND Screening for atherosclerosis is an important method for assessing cardiovascular (CV) risk. Our data with carotid imaging shows a normal a carotid is associated with a very low 10-year CV risk of 1.6%. Even a low risk carotid still predicts a favourable outcome, 5.6-7.0% CV risk over 10 years. Increasing plaque burden as assessed by either total plaque area (&amp;gt;25mm2) or plaque score (&amp;gt;1) is associated with increasing CV risk, ranging from 20% to &amp;gt;30% over 10 years. PURPOSE This analysis was performed to estimate the prevalence and severity of carotid disease in men and women presenting for stress ECHO, with no prior documented evidence of CV disease. METHODS Data was collected from October 3, 2011 to January 22, 2019. Male patients aged 40-70yrs and female patients aged 50-75yrs undergoing stress ECHO underwent a screening carotid examination prior to the test. This involves only 2-3 images on each side to include, the CCA, carotid bulb and ICA. Maximal CCA IMT is measured using an automatic edge detection method, plaque score is calculated using the Rotterdam method and plaque area is measured in the carotid bulb and ICA bilaterally. Total plaque area being the sum of all area measurements. Apart from age criteria, patients were also excluded if they were diabetic, already taking a statin, or had a previous history of any vascular disease. A low-risk carotid was defined as a maximal CCA IMT &amp;lt;1.00m,with a plaque score of "0" or "1" providing the total plaque area was &amp;lt;25mm2. An unpaired t-test was used to detect differences between means and the Fisher’s exact test was used to detect differences between proportions. A p value of &amp;lt;0.05 was considered statistically significant. RESULTS There were 1683 patients, 1175 females and 508 males with a mean age of 60.9 ± 7.4 years. Of the 1683 patients 1058 had evidence of carotid plaque (62.9%), 368 males (72.4%) and 690 females (58.7%). 726 patients were classified as low-risk and 957 patients were classified as high-risk. See Table 1. CONCLUSIONS A brief screening carotid examination prior to stress ECHO reveals a large percentage of both men and women who have evidence of atherosclerosis, of which 56.9% are high-risk. These patients could be identified while in the ECHO laboratory. The patients could then be offered guideline therapy with statin therapy and low dose ASA. Table 1. Number Age CCA IMT PS 0-1 PS 2-3 PS 4-6 Low-risk High-risk Males 508 58.4 ± 7.8 1.14 ± 0.47 138 213 56 161 347 Females 1175 62.0 ± 7.0 0.99 ± 0.49 726 395 54 565 610 P value &amp;lt;0.0001 &amp;lt;0.0001 &amp;lt;0.0001 &amp;lt;0.005 &amp;lt;0.0001 &amp;lt;0.0001 &amp;lt;0.0001 PS = Plaque score.

Retinal artery occlusion does not portend an increased risk of stroke

ObjectiveThe aim of this study was to determine the subsequent risk of stroke after a diagnosis of retinal artery occlusion (RAO). We hypothesized that the risk would be low and comparable to that of the general population. RAO is relatively rare and often incorrectly diagnosed. We believe our institution is in a unique position to investigate this relationship with both a high-volume eye center and vascular laboratory. MethodsThis was a retrospective, single-institution review of 221 patients diagnosed with RAO from 2004 to 2018, confirmed with fluorescein angiography. Demographics, comorbidities, imaging of the carotid arteries, and prospective events, such as stroke, myocardial infarction (MI), and death, were recorded. Time to first stroke, first MI, and death was estimated using Kaplan-Meier estimation separately and as a composite end point. ResultsThere were 221 patients identified with a confirmed diagnosis of RAO. The mean age in the cohort was 66.1 years; 53% of patients were male, and 29% were diabetic. Median length of follow-up was 2.2 years. Five patients (2.3%) had a documented stroke; four of the five strokes occurred at the time of RAO, with one that was contralateral occurring at 1.2 years. There were eight MIs (3.6%) in the cohort, two of which resulted in death. Twenty-two patients (10%) experienced a stroke, MI, or death. There were 141 (63.8%) patients who had carotid imaging performed, of whom 20 (14.2%) were found to have >50% stenosis. ConclusionsThe rate of stroke in patients with confirmed RAO was 2.3%; however, excluding concurrent ischemic events, the risk was <1%. The incidence of carotid artery stenosis >50% was 14.2%. The authors conclude that the risk of stroke after confirmed RAO is lower than previously reported and comparable to prior population-based studies of all at-risk adults.

One-Stop MR Neurovascular Vessel Wall Imaging With a 48-Channel Coil System at 3 T.

The purpose of this article was to build a radio frequency (RF) coil system to achieve high vessel wall image quality with coverage extending from the aortic arch to the intracranial vessels. A 48-channel coil system was built and characterized at a 3 tesla (T) Magnetic Resonance Imaging (MRI) scanner (uMR 790, Shanghai United Imaging Healthcare, Shanghai, China). The coil's performance was compared with a commercially available 36-channel coil system. By human studies, signal-to-noise ratio (SNR) units were evaluated and g-factors were calculated in the transverse planes of the brain and neck regions. The SNR was increased by at least 28% in the brain region and up to fourfold in the neck region. The average g-factor with the acceleration factor, R = 3, was lowered by 21% in the transverse plane of the neck region. Intracranial and carotid arterial wall images with an isotropic spatial resolution of 0.63 mm were acquired within 7.7 minutes and thoracic aorta wall images with an isotropic spatial resolution of 1.1 mm were acquired within 2.7 minutes with the 48-channel coil system. The vessel wall can be more clearly visualized with the 48-channel coil system compared with the 36-channel coil system. A 48-channel coil system was developed and demonstrated superior performance for vessel wall imaging at the intracranial and cervical carotid arteries compared with a commercial 36-channel coil. The 48-channel coil system is potentially useful for clinical diagnostics, especially when attempting to diagnose ischemic stroke.

Statin Naïve Patients with Myocardial Infarction have more Echolucent Plaques Compared to Long-term Statin Treated Chronic Atherosclerotic Patients – A 3D Ultrasound Study

Introduction: Size and morphology of carotid atherosclerotic plaques can be quantified by ultrasound (US) imaging. Carotid artery plaque size and gray-scale median (GSM) have been identified as risk markers for both cardiovascular events and stroke ADDIN EN.CITE ADDIN EN.CITE.DATA (1, 2). Unstable plaques have a thin fibrotic cap and a lipid or hemorrhagic core ADDIN EN.CITE ADDIN EN.CITE.DATA (3-6). A higher amount of lipid and hemorrhage have been observed in echolucent carotid plaques presenting as lower GSM compared to echogenic carotid plaques containing fibrotic tissue and calcification ADDIN EN.CITE ADDIN EN.CITE.DATA (7-10). Classic cardiovascular risk scores such as Framingham score lack precision ADDIN EN.CITE ADDIN EN.CITE.DATA (11, 12). Information about atherosclerotic plaque characteristics and development can potentially improve risk stratification. Methods: : Two patient populations were included prospectively; a group admitted with first-time myocardial infraction and naive to statin treatment and a group followed for peripheral arterial disease on stable statin treatment for more than six months, all being ≤65 years old. Both carotid arteries were scanned with 3D ultrasound by the same sonographer. All plaques were analyzed using a semiautomated software. Gray-scale readings were normalized with adventitia as reference and GSM recorded. In patients with bilateral carotid artery plaques the thickest plaque was used for data analyses. Results: In the statin treated patients (n=70 , 64% male, mean age 60 (range 40-65)) compared to the statin naive patients (n= 70, 79% male, mean age 57 (range 38-65)) we found an increased plaque thickness (difference 0.65 mm, P=0.001), a larger plaque volume (difference 31.98 mm3, P=0.001) as well as a higher GSM (difference 9.46, 95% confidence interval: 1.59 - 17.33, P=0.019) (figure 1). The differences in thickness and volume disappeared after adjustment for age, gender, smoking, hypertension and diabetes mellitus (P= 0.066 and 0.050, respectively). The differences in GSM persisted after adjusting for volume (difference of 9.05, CI95%: 0.90 - 17.21, P=0.030). There was no correlation between volume and GSM (P=0.16). Conclusion: .By 3D US we detected differences in carotid plaque thickness, volume and morphology between two different atherosclerotic populations. The statin treated group with known clinical atherosclerotic disease, had larger plaques indicating a more advanced stage of disease as the difference diminished when adjusting for atherosclerotic risk factors. Also, this group had more echogenic plaques (higher GSM) which indicate less vulnerability, or a more stable stage of disease as compared to the statin naive group. Carotid 3D US imaging may prove clinically useful for identification and assessment of treatment response in high-risk patients with vulnerable plaques Disclosure: Co-author H. Sillesen has received research grants from Philips Ultrasound.