North American Symptomatic Carotid Endarterectomy Research Articles

ThP8.6 - A real-world diagnostic algorithm for identifying carotid artery stenosis

Abstract Aim Eighty-five percent of ischaemic strokes are caused by extracranial atheromatous lesions involving a narrowing of the Internal Carotid Artery so accurate and timely diagnosis is vital for management. The aim of this study was to correlate CT angiogram (CTA) and ultrasound doppler (US) derived measurements of carotid artery stenosis (CAS), with a view to identify those cases where second modality is required to reduce potential errors. Methods All consecutive carotid US and CTA examinations performed in 2021 and 2022 were included for comparison in this retrospective cohort study. Collected data was then reviewed and evaluated by a multidisciplinary team. North American Symptomatic Carotid Endarterectomy Trial (NASCET) and St Mary’s criteria were used to narrow down the percentage stenosis. Result There were fifty-one patients (102 carotid arteries) over this period who had both studies performed. Twenty-nine males and twenty-three females with a median age of seventy-three. Initial data analysis showed no discrepancy in ninety-one (90%) carotid arteries between both modalities. After MDT review, there were eight (7.1%) false positive results and three (2.9%) true positive (2 symptomatic & 1 asymptomatic). In three (2.9%) cases quantification was significantly inaccurate in the initial imaging modality because of heavily calcified vessels. Conclusion This study supports the use of US or CTA as a single modality in grading CAS. Heavily calcified vessels on the first test should be a ‘red flag’ for triggering further alternative imaging to reduce the risk of error. Persistent discrepancies even after the second modality will require a further modality e.g. enhanced magnetic resonance angiography.

Risk factors of internal carotid artery stenosis in patients with proliferative diabetic retinopathy: an analysis using optical coherence tomography and optical coherence tomography angiography

BackgroundThis research investigates the correlation between the severity of internal carotid artery (ICA) stenosis and retinal parameters in patients with proliferative diabetic retinopathy (PDR), aiming to uncover potential risk factors.MethodsA retrospective analysis of 68 patients (136 eyes) diagnosed with bilateral PDR from January 1, 2017, to December 31, 2021, was conducted. Carotid artery stenosis (CAS) was assessed using neck computed tomography angiography (CTA) and carotid duplex ultrasound (CDUS), with stenosis classified into two groups: normal (group 1) and mild or above (group 2), based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Optical coherence tomography (OCT) and OCT angiography (OCTA) measured several retinal parameters, including sub foveal choroidal thickness (SFCT), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, vessel density (VD), and foveal avascular zone (FAZ) area. Statistical analyses determined correlations between ICA degrees and retinal parameters.ResultsThis study showed significant differences between groups in total VD, FAZ area, total RNFL thickness, and temporal RNFL thickness, indicating that patients with more severe ICA stenosis had noticeable retinal changes. Other parameters such as hyperlipidemia, total cholesterol levels, and intraocular pressure (IOP) also differed significantly, while no notable differences were observed in SFCT, central VD, average GCIPL, and superior, nasal, and inferior RNFL thickness.ConclusionThe study findings highlight retinal changes, such as an increased FAZ area, decreased total VD, and a total and thinner temporal RNFL, which suggest the need for carotid artery evaluation in patients. These findings have important clinical implications for the need for carotid work up in patients with PDR.

Carotid Artery Stenting for Heavily Calcified Lesions Using a Scoring Balloon: A Report of 2 Cases

Objective Carotid artery stenting for heavily calcified lesions is challenging for interventionists. A calcium burden is associated with suboptimal dilatation, periprocedural complications, high rates of restenosis, and poor outcomes. We describe the first report of 2 cases of successful carotid artery stenting for heavily calcified lesions using a scoring balloon. Case Presentation The patients were both aged 75 years, 1 male and 1 female, who had experienced ipsilateral stroke prior to the procedures. They had dense calcifications at the lesions, stenosis rates of 95% (near occlusion) and 86% according to the North American Symptomatic Carotid Endarterectomy Trial criteria, and calcification arcs of 270° and 360°, respectively. Considering the heavy calcification, predilation with scoring balloons (NSE PTA balloon; Nipro, Osaka, Japan) at the rated burst pressure was performed in both cases. Sufficient dilatation was achieved, followed by carotid stent deployment (Precise Pro RX; Cordis, Miami Lakes, FL, USA). After postdilatation, the stenosis rates decreased to 21% and 23%, respectively. Although 1 patient experienced prolonged bradycardia and hypotension, they were well managed with anticholinergic and vasoconstrictive agents. Both patients remained asymptomatic. Conclusion Carotid artery stenting using a scoring balloon obtained acceptable improvements in severe stenosis with heavily calcified lesions. This method could be a useful option for the revascularization of heavily calcified lesions.

Local and systemic factors associated with quantitative stiffness of carotid plaque.

Plaque stiffness in carotid artery stenosis is a clinically important factor involved in the development of stroke and surgical complications. The purpose of this study was to clarify which local and systemic factors are associated with the quantitatively measured stiffness of plaque. The subjects were 104 consecutive patients who underwent carotid endarterectomy at our institution. To measure quantitative stiffness of plaque, we used an industrial hard meter in the operating room within 1h after removal of plaque. Local factors related to carotid plaque hardness were evaluated, including maximum intima-media thickness (max IMT), degree of stenosis using the European Carotid Surgery Trial (ECST), presence of ulceration or calcification, and echo brightness on preoperative carotid ultrasound. The degree of stenosis was also evaluated using the North American Symptomatic Carotid Endarterectomy Trial method in digital subtraction angiography. Age, sex, and presence or absence of hypertension, diabetes, and dyslipidemia (low-density lipoprotein cholesterol and triglyceride [TG] levels) served as systemic factors and were compared with the quantitative stiffness of carotid plaque. In multivariate analysis, ECST stenosis degree, calcification, and IMT max as local factors affected plaque stiffness. As a systemic factor, plaque stiffness was statistically significantly negatively correlated with TG values in multivariate analysis (p < 0.05). The quantitative stiffness of the plaque was negatively correlated with TG levels as a systemic factor in addition to local factors. This might suggest that reducing high TG levels is associated with plaque stabilization.

Correlation between Ultrasound Peak Systolic Velocity and Angiography for Grading Internal Carotid Artery Stenosis.

(1) Background: The success of carotid revascularization depends on the accurate grading of carotid stenoses. Therefore, it is important for every vascular center to establish its protocols for the same. In this study, we aimed to determine the peak systolic velocity (PSV) thresholds that can predict moderate and severe internal carotid artery (ICA) stenoses. (2) Methods: To achieve this, we enrolled patients who underwent both duplex ultrasound (DUS) and invasive carotid artery digital subtraction angiography (DSA). The degree of ICA stenosis was assessed using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) protocols. The PSV thresholds were determined using receiver operating characteristic (ROC) curves. (3) Results: Our study included 47 stenoses, and we found that the PSV cut-off for predicting ≥70% NASCET ICA stenoses was 200 cm/s (sensitivity 90.32%, specificity 93.75%). However, PSV did not correlate significantly with ≥50% NASCET ICA stenoses. On the other hand, the optimal PSV threshold for predicting ≥80% ECST ICA stenoses was 180 cm/s (sensitivity 100%, specificity 81.82%). (4) Conclusions: Based on our findings, we concluded that PSV is a good and simple marker for the identification of severe stenoses. We found that PSV values correlate significantly with severe NASCET and ECST stenoses, with 200 cm/s and 180 cm/s PSV thresholds. However, PSV was not reliable with moderate NASCET stenoses. In such cases, complementary imaging should be used.

PSAA-nnUNet: An Efficient Method for CT Carotid Artery Image Segmentation.

Carotid artery (CA) stenosis (CAS) constitutes a significant factor to ischaemic cerebrovascular events which exhibiting no overt symptoms in the early stages. Early detection of CAS can prevent ischaemic stroke and improve patient prognosis. In this study, we developed a non-invasive CAS automatic assessment method based on deep learning, intended for the early detection of CAS with CT imaging. The method proposed in this paper consists of three main components. First, we utilised thresholding and the Hessian-based Frangi filter to eliminate irrelevant tissue and enhance vascular structures. Second, we introduced a novel neural network named parameter shared axial attention (PSAA)-nnUNet for the automatic segmentation of CA. Finally, we assessed the degree of CAS with the North American Symptomatic Carotid Endarterectomy Trial (NASCET) formula. The PSAA-nnUNet algorithm proposed in this study achieved a segmentation accuracy of 0.82. The non-invasive CAS automatic assessment method based on PSAA-nnUNet exhibits excellent accuracy and great application potential.

European Carotid Surgical Trial-based diameter measurement using B-mode ultrasound imaging to quantify low-grade carotid artery stenosis: the QUAMUS study

BackgroundIdentification of carotid atherosclerotic lesions with no hemodynamic effect on Doppler ultrasound examination is a common situation. Although the use of B-mode ultrasound examination has been recommended to assess this type of lesion, there is no validated examination procedure to date for quantifying low-grade carotid stenosis. MethodsWe conducted a single-center prospective study (QUAntification Morphologique en UltraSonographie [QUAMUS] study) to assess the reproducibility of B-mode ultrasound quantification of low-grade internal carotid artery stenosis using the European Carotid Surgical Trial (ECST) measurement method. We included consecutive patients with <50% North American Symptomatic Carotid Endarterectomy Trial carotid stenosis identified by the University of Washington duplex criteria (ie, maximum systolic velocity of <125 cm/second at a Doppler angle of 50°-60°). The examination was carried out and interpreted independently, blindly, and successively by two operators according to a precise methodology based on the measurement of cross-sectional diameter in B-mode and calculation of the stenosis percentage according to the ECST method. The primary objective was to assess the measurement concordance of the stenosis percentage for a difference not exceeding 10% between the two operators. The secondary objective was to assess concordance in relation to examination quality. ResultsAmong the 86 patients included, 159 atherosclerotic carotid arteries were eligible and 157 could be explored (feasibility of 98.74%). The conditions were considered as good by the two operators in 69.43% of cases and poor in 2.55%. The concordance of the stenosis percentage measurement for a maximum difference of 10% between the two operators was 89.17% (95% confidence interval, 83.23-93.56) with a Lin concordance correlation coefficient of 0.87 (95% confidence interval, 0.82-0.90). Under examination conditions estimated as good, average, and poor, the concordance was 95.37%, 78.95%, and 60.00%, respectively. ConclusionsOur study shows that ECST-based B-mode ultrasound measurement of low-grade carotid stenosis is reliable and can be performed in routine practice in most patients with a measurement variation of <10% using a simple standardized examination procedure.

Carotid atherosclerosis in a sample of Egyptian patients with or without ischemic vascular events

BackgroundEthnic-racial factors are related to the development of extra- and intracranial atherosclerosis. There are extensive data about carotid atherosclerosis from American, European and Asian population. However, data from Egyptian ethnics are extremely rare. We aimed to examine the frequency and determine the predictors of carotid atherosclerosis in a sample of Egyptian patients. In a cross-sectional observational study, we prospectively recruited consecutive patients, with or without ischemic vascular events, either ischemic stroke or transient ischemic attack, who received neurovascular ultrasound in a tertiary hospital. We assessed the presence of carotid plaques and the degree of stenosis according to the hemodynamic North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria.ResultsA total of 668 carotid arteries in 334 patients with a mean (IQR) age of 61 (55–70) years were examined; 69.5% presented with and 30.5% without ischemic vascular events. We found carotid plaques in 208 (31.1%) arteries among 147 (44%) patients; 32% of the patients showed non-hemodynamically significant plaques, whereas 3.6% showed 20–40% internal carotid artery (ICA) stenosis and 8.4% showed ≥ 50% ICA stenosis. In patients with ischemic vascular events and at least one risk factor, we detected carotid atherosclerosis, 20–40% ICA stenosis and ≥ 50% ICA stenosis in 40.4%, 3% and 9.1% among patients ≤ 60 years as well as in 64.8%, 5.5% and 13% among patients > 60 years, respectively. In an age and sex adjusted binary logistic regression model, the following factors predicted carotid atherosclerosis: age > 60 years (OR 3.33, 95% CI 1.99–5.57, p < 0.001), hypertension (OR 2.3, 95% CI 1.32–4.02, p = 0.003), current smoking (OR 2.27, 95% CI 1.13–4.55, p = 0.02), diabetes mellitus (OR 2.15, 95% CI 1.27–3.64, p = 0.004) and ischemic vascular events (OR 1.8, 95% CI 1.01–3.19, p = 0.046).ConclusionsAmong Egyptians, the frequency of carotid atherosclerosis seems to be low. Further multiethnic studies are warranted to compare the prevalence of carotid atherosclerosis among Egyptians with Whites and Chinese populations. Older age, hypertension, smoking, diabetes mellitus and ischemic vascular events are predictors of carotid atherosclerosis.

Complications and outcomes of carotid artery stenting in high-risk cases

ObjectivesCarotid artery stenting is sometimes adapted for some at-risk cases; however, appropriate treatment timing with stroke onset is controversial. This study aims to identify factors that have an impact on complications and outcomes, especially in patients at high risk. Materials and MethodsWe examined the characteristics of 152 consecutive patients treated by carotid artery stenting between January 2018 and March 2022 and retrospectively analyzed the risk factors for complications and poor outcomes (modified-Rankin-Scale deterioration), such as patient background, carotid artery stenting risks (access route tortuosity, severe calcification, vulnerable plaque, estimated glomerular filtration rate <30 mL/min/1.73 m2, etc.), characteristics of the stenosis, details of treatment, and treatment timing. ResultsThe average North American Symptomatic Carotid Endarterectomy Trial criteria score was 68.3% and the lesion length was 20.5±9.7mm. Among patients, 107 (70.4%) had a carotid artery stenting risk. In high-risk carotid artery stenting cases, symptomatic complications occurred in 32 (30.0%), and the 90-day modified Rankin scale score deteriorated in 15 cases (14.0%). Multivariate analysis showed that cases with triple antithrombotic therapy (p=0.003), stenting within 7 days (p=0.0032), and after 28+ days (p=0.0035) of stroke onset were independently associated factors for complications. ConclusionsThis study showed that among risk factors, triple antithrombotic therapy in particular was a risk factor for perioperative complications. Carotid artery stenting for patients with stroke after 28 days of onset affects the prognosis. Therefore, although further study is warranted, waiting more than one month for treatment in patients requiring carotid artery stenting is a potential risk.

Correlation Between Intracranial Calcification and Extracranial Stenosis of the Internal Carotid Artery.

Intracranial artery calcification is a marker of vascular atherosclerosis and has a high prevalence worldwide. Both atherosclerosis of the internal carotid artery at the carotid sinus in the neck and intracranial calcification have been associated with ischemic stroke. The relationship between the two has not been well studied. The present study investigated how carotid sinus narrowing could relate to calcification located in the distal intracranial artery at the cavernous carotid. We examined a population not selected for cerebral disease. This retrospective study contained 179 subjects aged 18 years and older from the Hawaii Diagnostic Radiology database. Extracranial internal carotid artery stenosis was determined using the absolute diameter, North American Symptomatic Carotid Endarterectomy Trial, and common carotid artery methods. Calcification was scored using the modified Woodcock method. A positive correlation between intracranial calcification and extracranial carotid stenosis was found using all three methods. Individuals with intracranial calcification were more likely to be older, have a smaller internal carotid artery diameter, and have a greater percent stenosis at the internal carotid artery than those without intracranial artery calcification (p<0.001 for all). These results may help refocus interest in calcification in studies of cerebral vasculature and its correlation with extracranial carotid stenosis.

Wall shear rate and energy loss coefficient measures using conventional Doppler ultrasound do not predict carotid plaque progression.

Background: The rate of carotid plaque progression is believed to be related to blood flow hemodynamics and shear stress. Our objective was to determine if wall shear rate (WSR) and the energy loss coefficient (ELC) measured by Doppler ultrasound could predict atherosclerotic carotid disease progression. Patients and methods: Patients at a large tertiary center with an initial ultrasound between 2016 and 2018 with a significant carotid plaque were included if they had at least one 6 months follow-up comparative study. Stenosis progression was assessed according to the NASCET (The North American Symptomatic Carotid Endarterectomy Trial) percentage criterion. Results: The average annual progression rate for the 74 plaques included was 5.7% NASCET per year. We identified 18 plaques with ≥10% NASCET progression and 56 plaques without significant progression <10% NASCET. Among the plaques with progression, only four plaques had progression greater than 20% NASCET. Median WSR was 6266 s-1 [5813-8974] in plaques with progression and 6564 s-1 [5285-8766] in stable plaques (p=0.643). Median ELC was 3.86 m2 [2.78-5.53] in plaque with progression and 4.32 m2 [3.42-6.81] in stable plaques (p=0.296). Conclusions: Although it is a widely accepted hypothesis that shear stress and hemodynamics of the carotid bifurcation contribute to plaque progression, we found that WSR and ELC estimated by Doppler ultrasound do not reliably predict atherosclerotic plaque progression in the carotid artery. Other ultrasound modalities, such as 3D imaging, may be used to assess the influence of plaque geometry and hemodynamics in plaque progression.

Evaluation of ocular blood flow in the assessment of symptomatic carotid stenosis.

The degree of internal carotid artery (ICA) stenosis determined by criteria from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) is not the most accurate index to assess distal flow compromise. Distal ICA perfusion is also determined by factors such as tandem carotid stenosis and collateral circulation. Quantification of end-organ ocular perfusion using non-invasive laser speckle flowgraphy (LSFG) may provide insights into distal ICA flow. This study prospectively assessed the degree of ICA flow using LSFG. Eighteen patients with symptomatic carotid stenosis underwent LSFG evaluation. LSFG was used to extract ocular blood flow metrics recorded simultaneously in the retina, choroid, and optic nerve head. The following ocular flow parameters were measured with LSFG: mean blur rate (MBR), flow acceleration index (FAI), and rising rate (RR). Syngo iFlow perfusion imaging was used to objectively quantify contrast flow in the ICA and brain parenchyma during digital subtraction angiography. Time to peak (TTP) and contrast delay were extracted from seven different regions of interest (ROIs). MBR, FAI, and RR were correlated with NASCET degree of stenosis. FAI and RR also improved after stenting. TTP improved after stenting in three ROIs. A moderate negative correlation was observed between FAI and contrast delay. LSFG non-invasively quantifies end-organ blood flow distal to the ICA origin. LSFG metrics have the potential to quantify end-organ perfusion and determine if a proximal carotid stenosis is symptomatic.

Impact of calcified plaque volume on technical and 3-year outcomes after transcarotid artery revascularization

ObjectiveWe sought to quantify the percent calcification within carotid artery plaques and assess its impact on percent residual stenosis and rate of restenosis in patients undergoing transcarotid artery revascularization for symptomatic and asymptomatic carotid artery stenosis. MethodsA retrospective review of prospectively collected institutional Vascular Quality Initiative data was performed to identify all patients undergoing transcarotid artery revascularization from December 2015 to June 2021 (n = 210). Patient and lesion characteristics were extracted. Using a semiautomated workflow, preoperative computed tomography head and neck angiograms were analyzed to determine the calcified plaque volume in distal common carotid artery and internal carotid artery plaques. Intraoperative digital subtraction angiograms were reviewed to calculate the percent residual stenosis post-intervention according to North American Symptomatic Carotid Endarterectomy Trial criteria. Peak systolic velocity and end-diastolic velocity were extracted from outpatient carotid duplex ultrasound examinations. Univariate logistic regression was performed to analyze the relationship of calcium volume percent and Vascular Quality Initiative lesion calcification to percent residual stenosis in completion angiograms. Kaplan-Meier analysis examined the relationship between calcium volume percent and in-stent stenosis over 36 months. ResultsOne hundred ninety-seven carotid arteries were preliminarily examined. Predilation was performed in 87.4% of cases with a mean balloon diameter of 5.1 ± 0.7 mm and a mean stent diameter was 8.8 ± 1.1 mm. The mean calcium volume percent was 11.9 ± 12.4% and the mean percent residual stenosis was 16.1 ± 15.6%. Univariate logistic regression demonstrated a statistically significant difference between calcium volume percent and percent residual stenosis (odds ratio [OR], 1.324; 95% confidence interval [CI], 1.005-1.746; P = .046). Stratified by quartile, only the top 25% of calcified plaques (>18.7% calcification) demonstrated a statistically significant association with higher percent residual stenosis (OR, 2.532; 95% CI, 1.049-6.115; P =.039). There was no statistical significance with lesion calcification (OR, 1.298; 95% C,: 0.980-1.718; P = .069). A Kaplan-Meier analysis demonstrated a statistically significant increase in the rate of in-stent stenosis during a 36-month follow-up for lesions containing >8.2% calcium volume (P = .0069). ConclusionsA calcium volume percent of >18.7% was associated with a higher percent residual stenosis, and a calcium volume percent of >8.2% was associated with higher in-stent stenosis at 36 months. There was one clinically diagnosed stroke during the follow-up period, demonstrating the overall safety of the procedure.

Predicting transient ischemic attack risk in patients with mild carotid stenosis using machine learning and CT radiomics.

This study aims to establish a radiomics-based machine learning model that predicts the risk of transient ischemic attack in patients with mild carotid stenosis (30-50% North American Symptomatic Carotid Endarterectomy Trial) using extracted computed tomography radiomics features and clinical information. A total of 179 patients underwent carotid computed tomography angiography (CTA), and 219 carotid arteries with a plaque at the carotid bifurcation or proximal to the internal carotid artery were selected. The patients were divided into two groups; patients with symptoms of transient ischemic attack after CTA and patients without symptoms of transient ischemic attack after CTA. Then we performed random sampling methods stratified by the predictive outcome to obtain the training set (N = 165) and testing set (N = 66). 3D Slicer was employed to select the site of plaque on the computed tomography image as the volume of interest. An open-source package PyRadiomics in Python was used to extract radiomics features from the volume of interests. The random forest and logistic regression models were used to screen feature variables, and five classification algorithms were used, including random forest, eXtreme Gradient Boosting, logistic regression, support vector machine, and k-nearest neighbors. Data on radiomic feature information, clinical information, and the combination of these pieces of information were used to generate the model that predicts the risk of transient ischemic attack in patients with mild carotid artery stenosis (30-50% North American Symptomatic Carotid Endarterectomy Trial). The random forest model that was built based on the radiomics and clinical feature information had the highest accuracy (area under curve = 0.879; 95% confidence interval, 0.787-0.979). The combined model outperformed the clinical model, whereas the combined model showed no significant difference from the radiomics model. The random forest model constructed with both radiomics and clinical information can accurately predict and improve discriminative power of computed tomography angiography in identifying ischemic symptoms in patients with carotid atherosclerosis. This model can aid in guiding the follow-up treatment of patients at high risk.

Clinical Application of High-Frame-Rate Vector Flow Imaging in Evaluation of Carotid Atherosclerotic Stenosis.

This study seeks to evaluate the value of the high-frame-rate vector flow imaging technique in assessing the hemodynamic changes of carotid atherosclerotic stenosis in aging people (>60 years old). Aging patients diagnosed with carotid atherosclerotic stenosis who underwent carotid high-frame-rate vector flow imaging examination were prospectively enrolled. A Mindray Resona7s ultrasound machine equipped with high-frame-rate vector flow function was used for ultrasound evaluation. First, B mode ultrasound and color Doppler flow imaging were used to evaluate carotid stenosis. Then, the vector arrows and flow streamline detected by V Flow were analyzed and the wall shear stress values (Pa) at the carotid stenosis site were measured. All patients were divided into symptomatic and asymptomatic groups according to whether they had acute/subacute stroke or other clinical symptoms within 2 weeks before ultrasound examination. The results of digital subtraction angiography or computed tomography angiography were used as the gold standard. The stenosis rate was calcified, according to North American Symptomatic Carotid Endarterectomy Trial criteria. The diagnostic values of wall shear stress, conventional ultrasound, and the combined diagnosis in carotid atherosclerotic stenosis were compared. Finally, 88 patients with carotid atherosclerotic plaque were enrolled (71 males (80.7%), mean age 67.6 ± 5.4 years). The success rate of high-frame-rate vector flow imaging was 96.7% (88/91). The WSS value of symptomatic carotid stenosis (1.4 ± 0.15 Pa) was significantly higher than that of asymptomatic carotid stenosis (0.80 ± 0.08 Pa) (p < 0.05). Taking the wall shear stress value > 0.78 Pa as the diagnostic criteria for symptomatic carotid atherosclerotic plaque, the area under receiver operating characteristic curves was 0.79 with 87.1% sensitivity and 69.6% specificity. The area under receiver operating characteristic curves of the combined diagnosis (0.966) for differentiating severe carotid atherosclerotic stenosis was significantly higher than that of conventional ultrasound and WSS value, with 89.7% sensitivity and 93.2% specificity (p < 0.05). As a non-invasive imaging method, the high-frame-rate vector flow imaging technique showed potential value in the preoperative assessment of the symptomatic carotid atherosclerotic stenosis and diagnosing carotid atherosclerotic stenosis in aging patients.

Accuracy of the Society of Radiologists in Ultrasound (SRU) Carotid Doppler Velocity Criteria for Grading North American Symptomatic Carotid Endarterectomy Trial (NASCET) Stenosis: A Meta-Analysis.

The Society of Radiologists in Ultrasound (SRU) consensus panel proposed six Doppler velocity cut points for classifying internal carotid artery (ICA) stenosis of 50% and 70% according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. Their relative accuracies have not been compared. Meta-analysis performed following comprehensive literature review and identification of manuscripts with graphs of individual patient NASCET ICA stenosis measured by arteriography versus ICA peak-systolic velocity (PSV), end-diastolic velocity (EDV) and ICA PSV to common carotid artery (CCA) PSV. True positives, true negatives, false positives, and false negatives were calculated and used in two-level mixed effects models. Hierarchical summary receiver operating characteristic (ROC) curves were generated. Areas under the ROC curves were estimated. Nine studies performed between 1993 and 2016 were identified after review of 337 manuscripts. There were 1738 bifurcation data points extracted for PSV, 1026 for EDV, and 775 for ICA/CCA ratio. The highest sensitivity was 96% (95% CI: 93%, 98%) for PSV of 125 cm/s (50% stenosis) and highest specificity 86% (95% CI: 71%, 93%) for PSV of 230 cm/s (70% stenosis). Areas under the ROC curves ranged from a high of 0.93 (95% CI: 0.92, 0.95) for PSV (50% stenosis) to a low of 0.86 (95% CI: 0.84, 0.88) for EDV (70% stenosis). The SRU consensus Doppler cut points vary in their accuracies for predicting ICA stenosis. The PSV cut points have tradeoffs: high sensitivity/low specificity for 50% stenosis and high specificity/moderate sensitivity for 70% stenosis.

Vascular Imaging Follow‐Up in Carotid Webs: Is There Vascular Remodeling?

Vascular Imaging Follow‐Up in Carotid Webs: Is There Vascular Remodeling?

Prediction of long-term mortality for patients with severe asymptomatic de novo carotid stenosis undergoing carotid endarterectomy (PREMY2SE-CEA): Derivation and validation of a novel risk score

ObjectiveThe aim of the present study was to develop and validate a risk prediction model for the prediction of long-term mortality for patients with severe asymptomatic de novo carotid stenosis undergoing carotid endarterectomy (PREMY2SE-CEA). MethodsData were collected retrospectively from a dedicated database of consecutive patients who had undergone elective CEA for severe (>70% using the NASCET [North American Symptomatic Carotid Endarterectomy Trial] criteria) asymptomatic carotid stenosis at two Italian University Hospitals from 2008 through 2016. Internal validation of the score was performed after random sampling in a 3:1 fashion. The primary end point of the PREMY2SE-CEA risk score was the 5-year mortality. ResultsOf the 1214 patients, 901 were included in the derivation cohort and 313 in the validation cohort. Using multivariable logistic regression with backward elimination, a parsimonious model was derived. A risk score incorporating eight risk factors was generated and found to be highly predictive of long-term mortality in the derivation (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.28-1.41; P < .001) and validation (OR, 1.29; 95% CI, 1.21-1.37; P <.001) cohorts. The discrimination power in the receiver operating characteristic curve analysis was C = 0.775 (95% CI, 0.74-.80), and the optimism-corrected area under the curve in the bootstrapped samples was 0.761 (P < .001). A strong correlation was found between the predicted and actual mortality rates in the validation cohort (r = 0.71; P < .001). ConclusionsIn the present study, we have described the development, evaluation, and validation of a risk prediction model (PREMY2SE-CEA) for long-term mortality after CEA in asymptomatic patients. Physicians could use the PREMY2SE-CEA risk scoring tool to complement their estimates of life expectancy and prompt selective consideration of prophylactic CEA to improve the long-term benefits of interventions.

Carotid Ultrasound Using Superb Microvascular Imaging to Identify Patients Developing In-Stent Restenosis After CAS

Background and purposeIn-stent restenosis (ISR) caused by in-stent intimal hyperplasia (ISH) may develop after carotid artery stenting (CAS), and often necessitates re-stenting. We investigated whether new ultrasound technique is useful for detecting carotid artery plaques prone to ISR. PurposeSuperb micro-vascular imaging (SMI) is a new color Doppler imaging technique for assessing low velocity blood flow such as neovascularization in carotid artery plaques. In this study, we attempted to identify associations between findings from carotid ultrasonography with SMI performed prior to CAS and in-stent restenosis after 6 months of CAS. MethodsThis study investigated 19 patients (18 men; mean age, 72.4 years). Preoperative plaque evaluation was performed by magnetic resonance imaging, ultrasonography, and carotid angiography. Follow up angiography was performed in all patients at 6 months after CAS. ISR was defined as ISH resulting in >50% stenosis based on European Carotid Surgery Trialists criteria. We investigated whether SMI was useful as a predictor of ISR by chi-square test. ResultsPreoperative mean stenosis rate according to North American Symptomatic Carotid Endarterectomy Trial methods in 19 patients was 61.3%. Neovascularization was observed on SMI in 10 patients (52.6%). Carotid angiography at 6 months after CAS revealed ISR in 4 patients, all of whom had shown neovascularization on SMI. A significant association was seen between findings of neovascularization on SMI and development of ISR (p = 0.033). In predicting ISR, neovascularization findings on SMI offered 100.0% sensitivity and 60.0% specificity. ConclusionsPreprocedural plaque characterization by carotid ultrasound with SMI appears useful for predicting ISR at 6 months after CAS.

Relationship between Successful Cervical Carotid Stent Expansion and Low Levels of Serum Vitamin D

Background: Serum vitamin D levels affect atherosclerosis development via diverse molecular mechanisms. The lesion characteristics of carotid stenosis affect the success of stent expansion. By comparing the pre-and post-stenting stenosis degrees, our study evaluated whether serum vitamin D levels are associated with the expansion rate of carotid stenting.Methods: Forty-six cases who underwent elective cervical carotid artery stenting were analyzed. Patients were classified into two groups according to serum total 25-hydroxy vitamin D (25[OH]D) levels; &lt;15.1 and ≥15.1 ng/mL. The degree of stenosis before and after stent insertion was calculated using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. The stent expansion rate was calculated as follows: (1-[post-stent stenosis degree/pre-stent stenosis degree])×100 (%). To identify the independent factors for successful stent expansion, multivariable logistic regression analysis was conducted.Results: Among the 46 patients, 25 (54.3%) had low serum 25(OH)D levels. The successful stent expansion rate was significantly higher in the low 25(OH)D level group (48.0% vs. 19.0%, respectively; p=0.04). In multivariable analysis, after adjusting for possible covariates, a low serum 25(OH)D level was independently associated with successful stent expansion (adjusted odds ratio, 6.47; 95% confidence interval, 1.11-37.80).Conclusion: Low serum vitamin D levels were independently associated with successful carotid stent expansion. This study presents a new perception of biomarkers that should be considered for satisfactory carotid artery stenting.