Predictors and clinical significance of progression or regression of asymptomatic carotid stenosis

What Is the Best Technique for Treating Carotid Disease?

This is a comprehensive review of carotid artery revascularization techniques: Carotid Endarterectomy (CEA), Transfemoral Carotid Artery Stenting (TFCAS), and Transcarotid Artery Revascularization (TCAR). CEA is the gold standard and is particularly effective in elderly and high-risk patients. TFCAS, introduced as a less invasive alternative, poses increased periprocedural stroke risks. TCAR, which combines minimally invasive benefits with CEA's neuroprotection principles, emerges as a safer option for high-risk patients, showing comparable results to CEA and better outcomes than TFCAS. The decision-making process for carotid revascularization is complex and influenced by the patient's medical comorbidities and anatomic factors.

Pathological Intraplaque Hemorrhage as the Gold Standard to Assess the Efficacy of Ultrasound in Predicting Vulnerable Carotid Plaque Rupture

OBJECTIVE

To assess the clinical utility of ultrasound in predicting the risk of carotid vulnerable plaque rupture using pathological intraplaque hemorrhage as the gold standard.

METHODS

A total of 118 patients who underwent endarterectomy due to symptomatic carotid artery stenosis were enrolled. Conventional ultrasound assessed the plaque thickness, area stenosis rate, echo, and surface morphology. Neovascularization were assessed by contrast-enhanced ultrasound (CEUS) and tracing intraplaque nonenhanced areas. According to neovascularization grade (0-4), plaques were classified as low-, intermediate-, and high risk. Fresh intraplaque hemorrhage within the pathology was adopted as the gold standard for diagnosing plaque rupture risk. Thus, we divided patients into ruptured risk and nonruptured risk groups to assess the value of crucial factors for plaque rupture risk using ultrasound.

RESULTS

Of the 118 patients, hypertension accounted for 71.2%, hyperlipidemia 68.6%, diabetes 52.5%, and statin history 64.4%. In the rupture risk group, diabetes, smoking, and stenosis rate were significantly higher than the nonrupture risk group (P < .001); plaque thickness ≥4 mm (P > .05); and mainly hypoechoic with irregular surface morphology (P < .001), nonenhanced areas in the plaques (P < .001), and neovascularization >grade 2 (P < .001). Compared with the low-risk group, plaque rupture risk was 7.219 times higher in the medium-risk group and 18.333 times higher in the high-risk group. The kappa value of the interobserver consistency of crucial ultrasound parameters was >0.75, and the intraclass correlation coefficient was 0.919 (P < .01).

CONCLUSIONS

Both conventional ultrasound and CEUS have significant clinical importance in the prediction of rupture risk in vulnerable carotid plaques, thereby enabling stroke risk stratification and the assessment of plaque rupture risk.

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

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

Cost-Effectiveness of Screening Asymptomatic Carotid Stenosis by Atherosclerotic Cardiovascular Risk

Importance

Extracranial internal carotid artery stenosis (50-99% arterial narrowing) is an important risk factor for ischemic stroke. Yet, the benefits and harms of targeted screening for asymptomatic carotid artery stenosis (ACAS) have not been assessed in population-based studies.

Objective

To estimate the cost-effectiveness of one-time, targeted ACAS screening stratified by atherosclerotic cardiovascular disease (ASCVD) risk using the American Heart Association's Pooled Cohort Equations.

Design Setting and Participants

We developed a lifetime microsimulation model of ACAS and stroke for a hypothetical cohort representative of US adults aged 50-80 years without stroke history. We used the Cardiovascular Health Study to estimate the probability and severity of ACAS based on individual characteristics (e.g., age, sex, smoking status, blood pressure, and cholesterol). Stroke risks were functions of these characteristics and ACAS severity. In the model, individuals testing positive for >70% stenosis with Duplex ultrasound and a confirmatory diagnostic test undergo revascularization, which may reduce the risk of stroke but also introduces complication risks. Diagnostic performance parameters, revascularization benefits and risks, utility weights, and costs were estimated from published sources. Cost-effectiveness was assessed from the health care sector perspective using a $100,000/quality-adjusted life year (QALY) threshold.

Main Outcomes and Measures

Estimated stroke events prevented, lifetime costs, QALYs, and incremental cost-effectiveness ratios (ICERs) associated with ACAS screening. Costs (2023 USD) and QALYs were discounted at 3% annually.

Results

We found that screening individuals with a 10-year ASCVD risk >30% was the most cost-effective strategy, with an ICER of $89,000/QALY. This strategy would make approximately 11.9% of the population eligible for screening, averting an estimated 24,084 strokes. Results were sensitive to variations in the efficacy and complication risk of revascularization. In probabilistic sensitivity analysis, screening those in lower ASCVD risk groups (0-20%) only had a 0.6% chance of being cost-effective.

Conclusion and Relevance

A one-time screening may only be cost-effective for adults at a relatively high ASCVD risk. Our findings provide a framework that can be adapted as future clinical trial data continue to improve our understanding of the role of revascularization and intensive medical therapy in contemporary stroke prevention secondary to carotid disease.

The mid-term results of the Carotid Asymptomatic Stenosis (CARAS) observational study

INTRODUCTION

Carotid endarterectomy (CEA) in patients with asymptomatic carotid stenosis (ACAS) remains a subject of debate. Current recommendations are based on randomized trials conducted over 20 years ago and improvements in medical therapies may have reduced the risk of cerebral ischemic events (CIE). This study presents a mid-term analysis of results from an ongoing prospective observational study of ACAS patients to assess their CIE risk in a real-world setting.

METHODS

This is a prospective observational cohort study of patients with ACAS >60 % (NASCET criteria) identified in a single duplex ultrasonography (DUS) vascular laboratory (trial registered: NCT04825080). Patients were not considered for CEA due to their short life expectancy (<3 year) or absence of signs of plaque vulnerability (ulceration, ipoechogenic core). Patient enrollment started in January 2019 and ended in March 2020 with a targeted sample size of 300 patients.A 5-year follow-up was scheduled. Clinical characteristics, risk factors, and medical therapies were documented, and, when necessary, the best medical therapy (BMT), involving antiplatelet agents, blood pressure control, and statins, was recommended during clinical visits. The primary endpoint was to asses CIEs (including strokes, transient ischemic attacks, amaurosis-fugax) ipsilateral to ACAS along with plaque progression rate and patients survival. Follow-up involved annual clinical visit and carotid DUS examination, complemented by telephone interviews at six-month intervals.

RESULTS

The study included 307 patients, with an average age of 80 ± 7 years, of whom 55 % were male. Contralateral stenosis exceeding 60 % was present in 61 (20 %) patients. Seventy-seven percent of patients were on BMT. At a mean follow-up of 41±9 months, 7 ispilateral strokes and 9 TIAs occurred, resulting in 14 CIEs (2 patients experienced both TIA and stroke). According to Kaplan-Meier analysis, the 4-year CIE rate was 6±2 %, with an annual CIE rate of 1.5 %. Fifty-eight (19 %) patients had a stenosis progression which was associated with a higher 4-year estimated CIE rate compared to patients with stable plaque (10.3 % vs 3.2 %, P=.01). Similarly, a contralateral carotid stenosis >60 % was associated with a higher 4-year estimated CIE rate: 11.7 % vs 2.9 %, P=.002. These factors were independently associated with high risk for CIE at the multivariate COX analysis: Hazard Ratio (HR): 3.2; 95 % Confidence Interval: 1.1-9.2 and HR: 3.6; 95 % CI: 1.2-10.5.

CONCLUSION

The mid-term results of this prospective study suggest that the incidence of CIE in ACAS patients should not be underestimated, with plaque progression and contralateral stenosis serving as primary predictors of CIEs.

An international, multispecialty, expert-based Delphi Consensus document on controversial issues in the management of patients with asymptomatic and symptomatic carotid stenosis

OBJECTIVE

Despite the publication of various national/international guidelines, several questions concerning the management of patients with asymptomatic (AsxCS) and symptomatic (SxCS) carotid stenosis remain unanswered. The aim of this international, multi-specialty, expert-based Delphi Consensus document was to address these issues to help clinicians make decisions when guidelines are unclear.

METHODS

Fourteen controversial topics were identified. A three-round Delphi Consensus process was performed including 61 experts. The aim of Round 1 was to investigate the differing views and opinions regarding these unresolved topics. In Round 2, clarifications were asked from each participant. In Round 3, the questionnaire was resent to all participants for their final vote. Consensus was reached when ≥75% of experts agreed on a specific response.

RESULTS

Most experts agreed that: (1) the current periprocedural/in-hospital stroke/death thresholds for performing a carotid intervention should be lowered from 6% to 4% in patients with SxCS and from 3% to 2% in patients with AsxCS; (2) the time threshold for a patient being considered "recently symptomatic" should be reduced from the current definition of "6 months" to 3 months or less; (3) 80% to 99% AsxCS carries a higher risk of stroke compared with 60% to 79% AsxCS; (4) factors beyond the grade of stenosis and symptoms should be added to the indications for revascularization in AsxCS patients (eg, plaque features of vulnerability and silent infarctions on brain computed tomography scans); and (5) shunting should be used selectively, rather than always or never. Consensus could not be reached on the remaining topics due to conflicting, inadequate, or controversial evidence.

CONCLUSIONS

The present international, multi-specialty expert-based Delphi Consensus document attempted to provide responses to several unanswered/unresolved issues. However, consensus could not be achieved on some topics, highlighting areas requiring future research.

Common Carotid Artery Stenosis Degree as a Predictor of Cardiovascular Disease in a General Population: The Suita Study

BACKGROUND

The utility of screening for the degree of common carotid artery (CCA) stenosis as a predictor of cardiovascular disease (CVD) in a general population remains unclear.

METHODS AND RESULTS

We studied 4775 Japanese men and women whose CCA was measured using bilateral carotid ultrasonography at baseline (April 1994-August 2001). We calculated the degree of stenosis as a percentage of the stenotic area of the lumen in the cross-section perpendicular to the long axis. The Cox proportional hazards model was used to calculate multivariable-adjusted hazard ratios (HRs) with 95% CIs for incident CVD and its subtypes according to the degree of CCA stenosis. During the median 14.2 years of follow-up, 385 incident CVD events (159 coronary heart disease and 226 stroke) were documented. The degree of CCA stenosis was associated with increased risks of incident CVD, coronary heart disease, and stroke, with multivariable-adjusted HRs (95% CIs) for <25%, 25%-49%, and ≥50% stenosis with plaque compared with no CCA plaque of 1.37 (1.07-1.76), 1.72 (1.23-2.40), and 2.49 (1.69-3.67), respectively. Adding the CCA stenosis degree to traditional CVD risk factors increased Harrell's C statistics (0.772 [95% CI, 0.751-0.794] to 0.778 [95% CI, 0.758-0.799]; P=0.04) and improved the 10-year risk prediction ability (integrated discrimination improvement, 0.0129 [95% CI, 0.0078-0.0179]; P<0.001; continuous net reclassification improvement, 0.1598 [95% CI, 0.0297-0.2881]; P=0.01).

CONCLUSIONS

The degree of CCA stenosis may be used as a predictive marker for the development of CVD in the general population.

Quantifying Carotid Stenosis: History, Current Applications, Limitations, and Potential: How Imaging Is Changing the Scenario

Carotid artery stenosis is a major cause of morbidity and mortality. The journey to understanding carotid disease has developed over time and radiology has a pivotal role in diagnosis, risk stratification and therapeutic management. This paper reviews the history of diagnostic imaging in carotid disease, its evolution towards its current applications in the clinical and research fields, and the potential of new technologies to aid clinicians in identifying the disease and tailoring medical and surgical treatment.

Carotid Artery Operation Delay During the Covid-19 Pandemic: Results of a Multicenter International Study

BACKGROUND

To measure the impact of the COVID-19 pandemic on the management of patients with carotid artery stenosis.

METHODS

We prospectively collected data from 25 centers (19 centers in the United States and 6 centers internationally) on postponed carotid artery operations between March 2020 and January 2022. We describe the characteristics of these patients and their planned operations, along with outcomes including mortality and neurological deterioration during the period of operative delay due to the COVID-19 pandemic.

RESULTS

A total of 1,220 vascular operations were postponed during the pandemic, of them 96 patients presented with significant carotid stenosis (median stenosis of 71%; interquartile range; 70-80) and 80% of them were planned for carotid endarterectomy. Most patients were asymptomatic (69%), and 31% of patients were symptomatic (16% of patients had a stroke, 15% of patients had a transient ischemic attack, and 1% of patients experienced amaurosis fugax). The median length of surgical delay was 71 days (interquartile range: 45.5, 115.5). At the data entry time, 62% of patients had their carotid operations postponed and successfully completed. Most postponements (72%) were due to institutional policies aimed at resource conservation. During the delay, no patient decompensated or required an urgent operation. A total of 5 patients (5%) with carotid stenosis died while awaiting operations due to COVID-19.

CONCLUSIONS

Our study of a cohort of patients with carotid artery stenosis who underwent a median delay of 71 days during the COVID-19 pandemic showed a disparate operation delay between US regions and internationally, most postponements were due to hospital policy, and none of the patients deteriorated or required an emergency surgery during the delay.

What Is the Role of Transcarotid Artery Revascularization?

Carotid endarterectomy (CEA) is the gold-standard method of carotid revascularization in symptomatic patients with ≥50% and in asymptomatic patients with ≥70% stenosis. Transfemoral carotid artery stenting (TFCAS) has been associated with higher perioperative stroke rates compared to CEA in several studies. On the other hand, transcarotid artery revascularization (TCAR) has outperformed TFCAS in patients who are considered high risk for surgery. There is increasing data that supports TCAR as a safe and efficient technique with outcomes similar to those of CEA, but additional level-one studies are necessary to evaluate the long-term outcomes of TCAR in high- and standard-risk patients.

Contemporary Treatment of the Asymptomatic Carotid Patient

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

Carotid Artery Stenosis: A Look Into the Diagnostic and Management Strategies, and Related Complications

Carotid stenosis (CS) is a buildup of atherosclerotic plaque within the artery leading to a wide range of symptoms, from mild symptoms, including blurred vision and confusion, to much more life-threatening presentations, including paralysis due to stroke. The presentation is insidious, with symptoms exhibiting predominantly at severe stenosis; hence the emphasis is placed on the importance of early diagnosis, treatment, and lifestyle modifications. CS is seen undergoing almost the same pathogenesis of any atherosclerotic plaque formation, from endothelial damage of the artery lumen to the formation of a fibrous cap with a foam cell, lipid-filled core. The findings of our review article were consistent with the recent literature, depicting that comorbid hypertension, diabetes, and chronic kidney disease (CKD), and lifestyle aspects, including smoking and diet, played the most salient role in plaque development. Among several imaging modalities, duplex ultrasound (DUS) imaging is the widely preferred method in clinical practice. Carotid endarterectomy (CEA) and carotid stenting are the primarily advocated procedures for symptomatic severe stenosis, with similar long-term outcomes. Although, earlier clinical trials showed promising results in mitigating the risk of stroke among asymptomatic severe CS with surgical intervention. However, recent advancements have shifted the focus to medical management alone due to comparable results among the asymptomatic population. Both surgical and medical regimens are beneficial in treating patients, but it is still an ongoing debate as to which is predominantly superior. The currently advancing trials and research will help elucidate definitive guidelines. However, the massive impact of lifestyle modifications advocates some degree of individualized multidisciplinary management strategies.

The Unstable Carotid Plaque

Carotid revascularization is performed to prevent cerebrovascular events in patients with symptomatic (>50%) and asymptomatic high degree (>70%) carotid stenosis. As this operation carries significant risks for perioperative stroke, careful selection of patients who will benefit from the procedure is essential. Certain plaque characteristics, including texture, are associated with increased tendency for rupture and can be used to identify high-risk patients. Medical therapy, carotid endarterectomy, and carotid stenting are the mainstays for patient management. With careful selection of patients, all anesthesia techniques (general anesthesia, monitored anesthesia care, and regional anesthesia) can be used safely for these revascularization procedures.

Asymptomatic carotid artery stenosis: a summary of current state of evidence for revascularization and emerging high-risk features

Carotid artery stenosis is a leading cause of ischemic stroke. While management of symptomatic carotid stenosis is well established, the optimal approach in asymptomatic carotid artery stenosis (aCAS) remains controversial. The rapid evolution of medical therapies within the time frame of existing landmark aCAS surgical revascularization trials has rendered their findings outdated. In this review, we sought to summarize the controversies in the management of aCAS by providing the most up-to-date medical and surgical evidence. Subsequently, we compile the evidence surrounding high-risk clinical and imaging features that might identify higher-risk lesions. With this, we aim to provide a practical framework for a precision medicine approach to the management of aCAS.

Patent foramen ovale and risks of recurrence in stroke of determined etiology

OBJECTIVE

Patent foramen ovale (PFO) is often found in stroke patients with determined etiologies. PFO may be the actual cause of stroke in some of them. We determined whether the risk of recurrent ischemic stroke differs with PFO status in stroke patients with determined etiologies.

METHODS

This study included consecutive patients with stroke of determined etiology who underwent transesophageal echocardiography. We compared the rates of recurrent cerebral infarction in patients with versus without PFO, and according to PFO-Associated Stroke Causal Likelihood (PASCAL) classification.

RESULTS

Of 2314 included patients, 827 (35.7%) had PFO. During a median follow-up of 4.4 years, cerebral infarction recurred in 202 (8.7%). In multivariate modified Cox regression analyses, recurrence of infarction did not significantly differ between patients with PFO and those without PFO (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.64-1.17; P = 0.339). Interaction analysis showed a significant effect of PFO in patients < 65 years (adjusted P for interaction = 0.090). PFO was independently associated with a decreased risk of recurrent infarction in patients younger than 65 years (HR, 0.41; 95% CI, 0.20-0.85; adjusted P = 0.016). Patients with probable PFO-associated stroke on the PASCAL classification had a significantly lower risk of recurrent infarction than those without PFO (HR 0.31; 95% CI 0.10-0.97; P=0.044).

INTERPRETATION

Considering the generally low risk of recurrence in PFO-associated stroke, PFO may be the actual cause of stroke in some patients with determined etiologies, especially younger patients or those with PFO features of probable PFO-associated stroke. This article is protected by copyright. All rights reserved.

Cerebral ischemic events ipsilateral to carotid artery stenosis. The Carotid Asymptomatic Stenosis (CARAS) observational study: First year preliminary results

OBJECTIVE

To report the characteristics of the prospective observational cohort study "Carotid Asymptomatic Stenosis (CARAS)", including patients with asymptomatic carotid stenosis under medical treatment and their first year of follow-up, in order to estimate the risk of cerebral ischemic events.

METHODS

This is a prospective observational cohort study of CARAS>60% (Nascet criteria) patients, identified in a single duplex-ultrasonography (DUS) vascular laboratory (trail registration N: NCT04825080). Patient's enrollment started in January 2019 and ended in March 2020 with the follow-up conclusion scheduled in December 2025. The aimed sample size was calculated at 300 patients for a 5-year follow-up. The primary outcome were the incidence of ipsilateral neurologic ischemic events (stokes and transient ischemic attacks [TIA]), plaque progression rate, and survival. The follow-up was scheduled at six-month intervals for clinical visit and annually for DUS examination.

RESULTS

a total of 307 patients completed the first follow-up year. The mean age was 81±4 years, 55% were male. Contralateral stenosis >60% was present in 90 (29%) patients. Antiplatelet therapy and statins adherence was 80% and 88%, respectively. During the first year, 3 ispilateral strokes (1%) and 4 TIAs (1.3%) occurred, for a total of 2.3% ipsilateral ischemic events. During the first year, 43 (14%) plaques had a stenosis progression, which was correlated with the occurrence of neurological events (9.3% vs. 1.1%, P=.001, OR: 8.9; 95%CI: 1.9-41); 6 deaths (2%) occurred in the same period.

CONCLUSION

the preliminary one-year results of this prospective study suggest that the overall rate of any ipsilateral ischemic event, and specifically ipsilateral strokes, correlates with plaque progression.

Interleukin-6 Predicts Carotid Plaque Severity, Vulnerability, and Progression

BACKGROUND

IL-6 (interleukin-6) has important roles in atherosclerosis pathophysiology. To determine if anti-IL-6 therapy warrants evaluation as an adjuvant stroke prevention strategy in patients with carotid atherosclerosis, we tested whether circulating IL-6 levels predict carotid plaque severity, vulnerability, and progression in the prospective population-based CHS (Cardiovascular Health Study).

METHODS

Duplex carotid ultrasound was performed at baseline and 5 years. Baseline plaque severity was scored 0 to 5 based on North American Symptomatic Carotid Endarterectomy Trial grade of stenosis. Plaque vulnerability at baseline was the presence of markedly irregular, ulcerated, or echolucent plaques. Plaque progression at 5 years was a ≥1 point increase in stenosis severity. The relationship of baseline plasma IL-6 levels with plaque characteristics was modeled using multivariable linear (severity) or logistic (vulnerability and progression) regression. Risk factors of atherosclerosis were included as independent variables. Stepwise backward elimination was used with P>0.05 for variable removal. To assess model stability, we computed the E-value or minimum strength of association (odds ratio scale) that unmeasured confounders must have with log IL-6 and the outcome to suppress the association. We performed internal validation with 100 bootstrap samples.

RESULTS

There were 4334 participants with complete data (58.9% women, mean age: 72.7±5.1 years), including 1267 (29.2%) with vulnerable plaque and 1474 (34.0%) with plaque progression. Log IL-6 predicted plaque severity (β=0.09, P=1.3×10^-3), vulnerability (OR, 1.21 [95% CI, 1.05-1.40]; P=7.4×10^-3, E-value=1.71), and progression (OR, 1.44 [95% CI, 1.23-1.69], P=9.1×10^-6, E-value 2.24). In participants with >50% predicted probability of progression, mean log IL-6 was 0.54 corresponding to 2.0 pg/mL. Dichotomizing IL-6 levels did not affect the performance of prediction models.

CONCLUSIONS

Circulating IL-6 predicts carotid plaque severity, vulnerability, and progression. The 2.0 pg/mL cutoff could facilitate the selection of individuals that would benefit from anti-IL-6 drugs for stroke prevention.

Incidence of Ischemic Stroke in Patients With Asymptomatic Severe Carotid Stenosis Without Surgical Intervention

IMPORTANCE

Optimal management of patients with asymptomatic severe carotid stenosis is uncertain, due to advances in medical care and a lack of contemporary data comparing medical and surgical treatment.

OBJECTIVE

To estimate stroke outcomes among patients with medically treated asymptomatic severe carotid stenosis who did not undergo surgical intervention.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study that included 3737 adult participants with asymptomatic severe (70%-99%) carotid stenosis diagnosed between 2008 and 2012 and no prior intervention or ipsilateral neurologic event in the prior 6 months. Participants received follow-up through 2019, and all were members of an integrated US regional health system serving 4.5 million members.

EXPOSURES

Imaging diagnosis of asymptomatic carotid stenosis of 70% to 99%.

MAIN OUTCOMES AND MEASURES

Occurrence of ipsilateral carotid-related acute ischemic stroke. Censoring occurred with death, disenrollment, or ipsilateral intervention.

RESULTS

Among 94 822 patients with qualifying imaging studies, 4230 arteries in 3737 (mean age, 73.8 [SD 9.5 years]; 57.4% male) patients met selection criteria including 2539 arteries in 2314 patients who never received intervention. The mean follow-up in this cohort was 4.1 years (SD 3.6 years). Prior to any intervention, there were 133 ipsilateral strokes with a mean annual stroke rate of 0.9% (95% confidence interval [CI], 0.7%-1.2%). The Kaplan-Meier estimate of ipsilateral stroke by 5 years was 4.7% (95% CI, 3.9%-5.7%).

CONCLUSIONS AND RELEVANCE

In a community-based cohort of patients with asymptomatic severe carotid stenosis who did not undergo surgical intervention, the estimated rate of ipsilateral carotid-related acute ischemic stroke was 4.7% over 5 years. These findings may inform decision-making regarding surgical and medical treatment for patients with asymptomatic severe carotid artery stenosis.

[Stroke risk stratification in elderly patients with comorbid sarcopenia and atherosclerosis]

OBJECTIVE

The study was to investigate the features of carotid arteries atherosclerosis as the leading risk factor for atherothrombotic stroke in elderly patients depending on the presence of sarcopenia.

MATERIAL AND METHODS

2 groups of patients above the working age were examined: 110 patients with normal muscle mass and 24 suffering sarcopenia. Ultrasound examination of carotid and vertebral arteries extracranial segments was performed with an assessment of atherosclerotic changes severity, atherosclerotic plaques instability, 10-year risk of stroke (according to Framingham risk score) and a 10-year risk of fatal cardiovascular disease (SCORE risk scale).

RESULTS

10-year risk of fatal cardiovascular disease was 3 [2; 5] points for patients without sarcopenia, 3 [2; 3] points for patients with sarcopenia (p=0.81). The 10-year risk of stroke was 16 [12; 18] for patients without sarcopenia, 18 [15; 22] points for patients with sarcopenia (p=0.1). Due to the ultrasound examination data the incidence of carotid arteries atherosclerotic lesions in patients without sarcopenia was 50 (46.3%), in patients with sarcopenia - 18 (75.0%) (p=0.01). Statistically significant (p<0.05) increase in the atherosclerotic plaques instability signs was revealed in patients suffering sarcopenia compared to those without it: heterogeneous echotexture - 66.7% cases versus 38.2% (p=0.01), presence of hypoechoic masses - 41.7% patients vs 12.7% (p=0.02).

CONCLUSION

It is important to take into account not only traditional risk factors in the overall assessment of cardiovascular risk as well as therapeutic and preventive measures planning in elderly patients, but also pay attention to body composition since modern diagnostic systems may be not sensitive enough to identify high-risk patients with comorbid atherosclerosis and sarcopenia.

[Important recommendations of the German-Austrian S3 guidelines on management of extracranial carotid artery stenosis]

BACKGROUND

Lesions of the extracranial carotid artery are the cause of 10-15 % of all cases of cerebral ischemia. The aims of the updated S3 guidelines are evidence-based and consensus-based recommendations for action on comprehensive care of patients with extracranial carotid stenosis in Germany and Austria.

METHODS

A systematic literature search (1990-2019) and methodical assessment of existing guidelines and systematic reviews were carried out. Consensus answers to 37 key questions with evidence-based recommendations.

RESULTS

The prevalence of extracranial carotid stenosis is approximately 4% and increases after the age of 65 years. The most important examination method is duplex sonography. Randomized controlled studies (RCT) have shown that carotid endarterectomy (CEA) of an asymptomatic 60-99% carotid artery stenosis reduces the absolute risk of stroke (absolute risk reduction, ARR) within 5 years in comparison to drug treatment alone by 4.1%. Due to an improved pharmaceutical prevention of arteriosclerosis, the S3 guidelines recommend a prophylactic CEA of a 60-99% stenosis only for patients without an increased surgical risk. Additionally, one or more clinical or imaging results should be present, which indicate an increased risk of carotid-related stroke in the follow-up. For medium-grade (50-69 %) and high-grade (70-99 %) symptomatic stenoses the ARRs after 5 years are 4.6% and 15.6%, respectively. Systematic reviews of RCTs have shown that CEA is associated with a ca. 50% lower periprocedural risk of stroke compared to carotid artery stenting (CAS). There are no differences in the long-term course. The CEA is recommended for high-grade asymptomatic, medium-grade and high-grade symptomatic carotid stenosis as a standard procedure, alternatively CAS can be considered. For both procedures the periprocedural stroke rate/mortality during hospitalization should be a maximum of 2% (asymptomatic stenosis) or 4% (symptomatic stenosis).

CONCLUSION

Both CEA and CAS necessitate a critical evaluation of the indications and strict quality criteria. Future studies should evaluate even better selection criteria for an individual, optimal, conservative, operative or endovascular treatment.

CurveletTransform-Based Texture Analysis of Carotid B-mode Ultrasound Images in Asymptomatic Men With Moderate and Severe Stenoses: A Preliminary Clinical Study

The curvelet transform, which represents images in terms of their geometric and textural characteristics, was investigated toward revealing differences between moderate (50%-69%, n = 11) and severe (70%-100%, n = 14) stenosis asymptomatic plaque from B-mode ultrasound. Texture features were estimated in original and curvelet transformed images of atheromatous plaque (PL), the adjacent arterial wall (intima-media [IM]) and the plaque shoulder (SH) (i.e., the boundary between plaque and wall), separately at end systole and end diastole. Seventeen features derived from the original images were significantly different between the two groups (4 for IM, 3 for PL and 10 for SH; 9 for end diastole and 8 for end systole); 19 of 234 features (2 for IM and 17 for SH; 8 for end systole and 11 for end diastole) derived from curvelet transformed images were significantly higher in the patients with severe stenosis, indicating higher magnitude, variation and randomness of image gray levels. In these patients, lower body height and higher serum creatinine concentration were observed. Our findings suggest that (a) moderate and severe plaque have similar curvelet-based texture properties, and (b) IM and SH provide useful information about arterial wall pathophysiology, complementary to PL itself. The curvelet transform is promising for identifying novel indices of cardiovascular risk and warrants further investigation in larger cohorts.

Optimal management of asymptomatic carotid stenosis in 2021: the jury is still out. An International, multispecialty, expert review and position statement

OBJECTIVES

The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement is to reconcile the conflicting views on the topic.

MATERIALS AND METHODS

A literature review was performed with a focus on data from recent studies.

RESULTS

Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients <75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses.

CONCLUSIONS

Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients.

A hybrid deep learning paradigm for carotid plaque tissue characterization and its validation in multicenter cohorts using a supercomputer framework

BACKGROUND

Early and automated detection of carotid plaques prevents strokes, which are the second leading cause of death worldwide according to the World Health Organization. Artificial intelligence (AI) offers automated solutions for plaque tissue characterization. Recently, solo deep learning (SDL) models have been used, but they do not take advantage of the tandem connectivity offered by AI's hybrid nature. Therefore, this study explores the use of hybrid deep learning (HDL) models in a multicenter framework, making this study the first of its kind.

METHODS

We hypothesize that HDL techniques perform better than SDL and transfer learning (TL) techniques. We propose two kinds of HDL frameworks: (i) the fusion of two SDLs (Inception with ResNet) or (ii) 10 other kinds of tandem models that fuse SDL with ML. The system Atheromatic™ 2.0_HDL (AtheroPoint, CA, USA) was designed on an augmentation framework and three kinds of loss functions (cross-entropy, hinge, and mean-square-error) during training to determine the best optimization paradigm. These 11 combined HDL models were then benchmarked against one SDL model and five types of TL models; thus, this study considers a total of 17 AI models.

RESULTS

Among the 17 AI models, the best performing HDL system was that comprising CNN and decision tree (DT), as its accuracy and area-under-the-curve were 99.78 ± 1.05% and 0.99 (p<0.0001), respectively. These values are 6.4% and 3.2% better than those recorded for the SDL and TL models, respectively. We validated the performance of the HDL models with diagnostics odds ratio (DOR) and Cohen and Kappa statistics; here, HDL outperformed DL and TL by 23% and 7%, respectively. The online system ran in <2 s.

CONCLUSION

HDL is a fast, reliable, and effective tool for characterizing the carotid plaque for early stroke risk stratification.

Optimal Management of Asymptomatic Carotid Stenosis in 2021: The Jury is Still Out. An International, Multispecialty, Expert Review and Position Statement

OBJECTIVES

The recommendations of international guidelines for the management of asymptomatic carotid stenosis (ACS) often vary considerably and extend from a conservative approach with risk factor modification and best medical treatment (BMT) alone, to a more aggressive approach with a carotid intervention plus BMT. The aim of the current multispecialty position statement is to reconcile the conflicting views on the topic.

MATERIALS AND METHODS

A literature review was performed with a focus on data from recent studies.

RESULTS

Several clinical and imaging high-risk features have been identified that are associated with an increased long-term ipsilateral ischemic stroke risk in patients with ACS. Such high-risk clinical/imaging features include intraplaque hemorrhage, impaired cerebrovascular reserve, carotid plaque echolucency/ulceration/ neovascularization, a lipid-rich necrotic core, a thin or ruptured fibrous cap, silent brain infarction, a contralateral transient ischemic attack/stroke episode, male patients < 75 years and microembolic signals on transcranial Doppler. There is growing evidence that 80-99% ACS indicate a higher stroke risk than 50-79% stenoses.

CONCLUSIONS

Although aggressive risk factor control and BMT should be implemented in all ACS patients, several high-risk features that may increase the risk of a future cerebrovascular event are now documented. Consequently, some guidelines recommend a prophylactic carotid intervention in high-risk patients to prevent future cerebrovascular events. Until the results of the much-anticipated randomized controlled trials emerge, the jury is still out regarding the optimal management of ACS patients.

A narrative review of plaque and brain imaging biomarkers for stroke risk stratification in patients with atherosclerotic carotid artery disease

Objective

In this narrative review, we aim to review imaging biomarkers that carry the potential to non-invasively guide stroke risk stratification for treatment optimization.

Background

Carotid atherosclerosis plays a fundamental part in the occurrence of ischemic stroke. International guidelines select the optimal treatment strategy still mainly based on the presence of clinical symptoms and the degree of stenosis for stroke prevention in patients with atherosclerotic carotid plaques. These guidelines, based on randomized controlled trials that were conducted three decades ago, recommend carotid revascularization in symptomatic patients with high degree of stenosis versus a conservative approach for most asymptomatic patients. Due to optimization of best medical therapy and risk factor control, it is suggested that a subgroup of symptomatic patients is at lower risk of stroke and may not benefit from revascularization, whereas a selective subgroup of high-risk asymptomatic patients would benefit from this procedure.

Methods

A literature search was performed for articles published up to December 2020 using PubMed, EMBASE and Scopus. Based on the literature found, change in stenosis degree and volume, plaque echolucency, plaque surface, intraplaque haemorrhage, lipid-rich necrotic core, thin fibrous cap, inflammation, neovascularization, microembolic signals, cerebrovascular reserve, intracranial collaterals, silent brain infarcts, diffusion weighted imaging lesions and white matters lesions have the potential to predict stroke risk.

Conclusions

The applicability of imaging biomarkers needs to be further improved before the potential synergistic prognostic ability of imaging biomarkers can be verified on top of the clinical biomarkers. In the future, the routine and combined assessment of both plaque and brain imaging biomarkers might help to improve optimization of treatment strategies in individual patients with atherosclerotic carotid artery disease.

A narrative review of the pathophysiology of ischemic stroke in carotid plaques: a distinction versus a compromise between hemodynamic and embolic mechanism

Atherosclerotic carotid artery stenosis causes about 10–20% of all ischemic strokes through two main mechanisms: hemodynamic impairment in case of significant stenosis and thromboembolism from an atherosclerotic plaque regardless of the degree of stenosis. The latter is the most frequent mechanism and appear to result from embolization from a vulnerable atherosclerotic plaque or acute occlusion of the carotid artery and propagation of thrombus distally. Downstream infarcts may occur in a territory of major cerebral artery or at the most distal areas between two territories of major cerebral arteries, the so-called watershed (WS), or border zone area. Although WS infarcts, especially deep WS infarct, were historically thought to be due to hemodynamic compromise, the role of microembolism has also been documented, both mechanisms may act synergistically to promote WS infarcts. Routine and more advanced imaging techniques may provide information on the underlying mechanism involved in ipsilateral ischemic stroke. A better understanding of ischemic stroke pathogenesis in carotid stenosis may limit the use of routine non-selective shunt, whose benefit-risk balance is debated, to patients with hemodynamic impairment.

After reviewing existing evidence underpinning the contribution of the two mechanisms in downstream ischemic stroke and the various imaging techniques available to investigate them, we will focus on the pathogenesis of WS infarcts that remains debated.

European Stroke Organisation guideline on endarterectomy and stenting for carotid artery stenosis

Atherosclerotic stenosis of the internal carotid artery is an important cause of stroke. The aim of this guideline is to analyse the evidence pertaining to medical, surgical and endovascular treatment of patients with carotid stenosis. These guidelines were developed based on the ESO standard operating procedure and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote recommendations. Based on moderate quality evidence, we recommend carotid endarterectomy (CEA) in patients with ≥60-99% asymptomatic carotid stenosis considered to be at increased risk of stroke on best medical treatment (BMT) alone. We also recommend CEA for patients with ≥70-99% symptomatic stenosis, and we suggest CEA for patients with 50-69% symptomatic stenosis. Based on high quality evidence, we recommend CEA should be performed early, ideally within two weeks of the last retinal or cerebral ischaemic event in patients with ≥50-99% symptomatic stenosis. Based on low quality evidence, carotid artery stenting (CAS) may be considered in patients < 70 years old with symptomatic ≥50-99% carotid stenosis. Several randomised trials supporting these recommendations were started decades ago, and BMT, CEA and CAS have evolved since. The results of another large trial comparing outcomes after CAS versus CEA in patients with asymptomatic stenosis are anticipated in the near future. Further trials are needed to reassess the benefits of carotid revascularisation in combination with modern BMT in subgroups of patients with carotid stenosis.

Hypothesis of "stroke-stop" formula: a tool for risk index determination in development of acute cerebrovascular disease in asymptomatic individuals with carotid stenosis

Background

Extracranial carotid artery disease is considered a risk factor for developing acute cerebrovascular diseases. The paper suggests the “Stroke-Stop” formula as hypothesis for the determination of the risk of developing stroke in asymptomatic individuals with carotid stenosis. The formula is based on a mathematical calculation of the major risk factors for stroke: the degree of ICA (internal carotid artery) stenosis, the morphological structure of the atherosclerotic plaque and the level of lipoprotein-associated phospholipase A2 (Lp-PLA2) concentration.

Methods

The cross sectional study included 70 patients with atherosclerotic ICA stenosis. Among vascular inflammatory markers, Lp-PLA2 was determined with concentration 252.7–328.6 mg/l. The obtained results were evaluated using descriptive statistics (the frequency, percentage ratio) as well as the one-way analysis of variance (ANOVA) and chi-square test.

Results

The risk of stroke development is eminently increasing with the progression of ICA stenosis and elevation of Lp-PLA2 levels. In patients with echolucent plaque, the risk of stroke development was significantly higher in correlation with patients with echogenic plaque. Based on calculations using “Stroke-Stop” formula, three main groups were generated: low (< 70 points), medium (70–100 points) and high (> 100 points) risk of stroke development.

Conclusions

Hypothesis of “Stroke-Stop” formula is proposed for better selection of patients who should be indicated for surgical treatment and will be evaluated in prospective study. In order to verify this hypothesis, we plan to do prospective study using “Stroke-Stop” formula for ipsilateral annual stroke rate in asymptomatic individuals with carotid stenosis who receive conservative therapy.

Stenosis, ulceration of the atherosclerotic plaque and Lp-PLA2 concentration are calculated

3 groups of stroke risk development were set (low, medium and high)

Proposed formula form personalized approach to the diagnosis and prevention of stroke

Management of patients with asymptomatic carotid stenosis may need to be individualized: a multidisciplinary call for action. Republication of J Stroke 2021;23:202-212

The optimal management of patients with asymptomatic carotid stenosis (ACS) is the subject of extensive debate. According to the 2017 European Society for Vascular Surgery guidelines, carotid endarterectomy should (Class IIa; Level of Evidence: B) or carotid artery stenting may be considered (Class IIb; Level of Evidence: B) in the presence of one or more clinical/imaging characteristics that may be associated with an increased risk of late ipsilateral stroke (e.g. silent embolic infarcts on brain computed tomography/magnetic resonance imaging, progression in the severity of ACS, a history of contralateral transient ischemic attack/stroke, microemboli detection on transcranial Doppler, etc.), provided documented perioperative stroke/death rates are <3% and the patient's life expectancy is >5 years. Besides these clinical/imaging characteristics, there are additional individual, ethnic/racial or social factors that should probably be evaluated in the decision process regarding the optimal management of these patients, such as individual patient needs/patient choice, patient compliance with best medical treatment, patient sex, culture, race/ethnicity, age and comorbidities, as well as improvements in imaging/operative techniques/outcomes. The present multispecialty position paper will present the rationale why the management of patients with ACS may need to be individualized.

Establishing a carotid artery stenosis disease cohort for comparative effectiveness research using natural language processing

OBJECTIVE

Investigation of asymptomatic carotid stenosis treatment is hindered by the lack of a contemporary population-based disease cohort. We describe the use of natural language processing (NLP) to identify stenosis in patients undergoing carotid imaging.

METHODS

Adult patients with carotid imaging between 2008 and 2012 in a large integrated health care system were identified and followed through 2017. An NLP process was developed to characterize carotid stenosis according to the Society of Radiologists in Ultrasound (for ultrasounds) and North American Symptomatic Carotid Endarterectomy Trial (NASCET) (for axial imaging) guidelines. The resulting algorithm assessed text descriptors to categorize normal/non-hemodynamically significant stenosis, moderate or severe stenosis as well as occlusion in both carotid ultrasound (US) and axial imaging (computed tomography and magnetic resonance angiography [CTA/MRA]). For US reports, internal carotid artery systolic and diastolic velocities and velocity ratios were assessed and matched for laterality to supplement accuracy. To validate the NLP algorithm, positive predictive value (PPV or precision) and sensitivity (recall) were calculated from simple random samples from the population of all imaging studies. Lastly, all non-normal studies were manually reviewed for confirmation for prevalence estimates and disease cohort assembly.

RESULTS

A total of 95,896 qualifying index studies (76,276 US and 19,620 CTA/MRA) were identified among 94,822 patients including 1059 patients who underwent multiple studies on the same day. For studies of normal/non-hemodynamically significant stenosis arteries, the NLP algorithm showed excellent performance with a PPV of 99% for US and 96.5% for CTA/MRA. PPV/sensitivity to identify a non-normal artery with correct laterality in the CTA/MRA and US samples were 76.9% (95% confidence interval [CI], 74.1%-79.5%)/93.1% (95% CI, 91.1%-94.8%) and 74.7% (95% CI, 69.3%-79.5%)/94% (95% CI, 90.2%-96.7%), respectively. Regarding cohort assembly, 15,522 patients were identified with diseased carotid artery, including 2674 exhibiting equal bilateral disease. This resulted in a laterality-specific cohort with 12,828 moderate, 5283 severe, and 1895 occluded arteries and 326 diseased arteries with unknown stenosis. During follow-up, 30.1% of these patients underwent 61,107 additional studies.

CONCLUSIONS

Use of NLP to detect carotid stenosis or occlusion can result in accurate exclusion of normal/non-hemodynamically significant stenosis disease states with more moderate precision with lesion identification, which can substantially reduce the need for manual review. The resulting cohort allows for efficient research and holds promise for similar reporting in other vascular diseases.

Management of Patients with Asymptomatic Carotid Stenosis May Need to Be Individualized: A Multidisciplinary Call for Action

The optimal management of patients with asymptomatic carotid stenosis (ACS) is the subject of extensive debate. According to the 2017 European Society for Vascular Surgery guidelines, carotid endarterectomy should (Class IIa; Level of Evidence: B) or carotid artery stenting may be considered (Class IIb; Level of Evidence: B) in the presence of one or more clinical/imaging characteristics that may be associated with an increased risk of late ipsilateral stroke (e.g., silent embolic infarcts on brain computed tomography/magnetic resonance imaging, progression in the severity of ACS, a history of contralateral transient ischemic attack/stroke, microemboli detection on transcranial Doppler, etc.), provided documented perioperative stroke/death rates are <3% and the patient’s life expectancy is >5 years. Besides these clinical/imaging characteristics, there are additional individual, ethnic/racial or social factors that should probably be evaluated in the decision process regarding the optimal management of these patients, such as individual patient needs/patient choice, patient compliance with best medical treatment, patient sex, culture, race/ethnicity, age and comorbidities, as well as improvements in imaging/operative techniques/outcomes. The present multispecialty position paper will present the rationale why the management of patients with ACS may need to be individualized.

Frailty Measurement and Implications for Cerebrovascular Disease Management in a Veteran Based Population

BACKGROUND

Rapid and objective preoperative assessment of patients undergoing carotid endarterectomy (CEA) remains difficult and variable. The Risk Analysis Index (RAI) is a validated medical record-based assessment of frailty that has been used to predict clinical outcomes for patients undergoing surgical procedures including CEA. We applied RAI to a veteran population following CEA for asymptomatic cerebrovascular disease and examined the factors related to post-operative morbidity and mortality.

METHODS

After obtaining IRB approval, Veteran Affairs Surgical Quality Improvement Program data was queried for CEA procedures from 2002 to 2015 for ICD-9 codes indicating asymptomatic patients. RAI was then calculated based on Veteran Affairs Surgical Quality Improvement Program variable medical record extraction. Three groupings of patients were undertaken including non-frail (RAI < 30), frail (RAI 30-34) and very frail (RAI ≥ 35). Chi squared and ANOVA were used to assess cohort differences. Binary logistic regression was used to evaluate predictors of post-operative stroke, myocardial infarction (MI), any complication, and death.

RESULTS

Between 2002 and 2015, 37,873 asymptomatic patients underwent CEA. Over 98% (37,266) of the patients were male with an average age of 68.3 ± 8.55 years. The cohorts contained 82.8% (n = 31,362), 12.4% (n = 4,678), and 4.8% (n = 1,833) for the non-frail, frail and very frail groups respectively. Frailty was associated with increased rates of post-operative stroke, MI, any complication, death, and longer hospital length of stay (P< 0.001). Operative time did not significantly differ between the groups. Increasing frailty was associated with having one or more complications (OR 1.69, 95% CI 1.50-1.90 for frail and OR 2.79, 95% CI 2.41-3.24 for very frail, (P< 0.001), post-operative stroke in frail (OR 1.33 95% CI 1.06-1.67) and very frail (OR 1.57 1 95% CI 1.14-2.16) patients, and MI in both frail (OR 1.68, CI 1.17-2.43) and very frail (OR 3.73, CI 2.52-5.51) patients. Frailty was also significantly associated with death with in very frail patients (OR 4.14, 95% CI 3.00-5.71, P< 0.001).

CONCLUSION

Increasing frailty as determined by RAI was associated with worse post-operative outcomes in asymptomatic patients undergoing CEA. Higher RAI score cohorts were associated with higher rates of postoperative stroke, MI, complications, and death. We recommend the use of this frailty index as a screening tool to guide risk discussions with asymptomatic patients undergoing CEA.

The TAXINOMISIS Project: A multidisciplinary approach for the development of a new risk stratification model for patients with asymptomatic carotid artery stenosis

INTRODUCTION

Asymptomatic carotid artery stenosis (ACAS) may cause future stroke and therefore patients with ACAS require best medical treatment. Patients at high risk for stroke may opt for additional revascularization (either surgery or stenting) but the future stroke risk should outweigh the risk for peri/post-operative stroke/death. Current risk stratification for patients with ACAS is largely based on outdated randomized-controlled trials that lack the integration of improved medical therapies and risk factor control. Furthermore, recent circulating and imaging biomarkers for stroke have never been included in a risk stratification model. The TAXINOMISIS Project aims to develop a new risk stratification model for cerebrovascular complications in patients with ACAS and this will be tested through a prospective observational multicentre clinical trial performed in six major European vascular surgery centres.

METHODS AND ANALYSIS

The risk stratification model will compromise clinical, circulating, plaque and imaging biomarkers. The prospective multicentre observational study will include 300 patients with 50%-99% ACAS. The primary endpoint is the three-year incidence of cerebrovascular complications. Biomarkers will be retrieved from plasma samples, brain MRI, carotid MRA and duplex ultrasound. The TAXINOMISIS Project will serve as a platform for the development of new computer tools that assess plaque progression based on radiology images and a lab-on-chip with genetic variants that could predict medication response in individual patients.

CONCLUSION

Results from the TAXINOMISIS study could potentially improve future risk stratification in patients with ACAS to assist personalized evidence-based treatment decision-making.

Diagnosis, Treatment and Follow-up in Extracranial Carotid Stenosis

BACKGROUND

Around 15% of cerebral ischemias are caused by lesions of the extracranial carotid artery. The goal of this guideline is to provide evidence- and consensus-based recommendations for the management of patients with extracranial carotid stenoses throughout Germany and Austria.

METHODS

A systematic literature search (1990-2019) and methodical assessment of existing guidelines and systematic reviews; consensus-based answers to 37 key questions with evidence-based recommendations.

RESULTS

The prevalence of extracranial carotid artery stenoses is around 4% overall, higher from the age of 65 years. The most important examination modality is duplex sonography. Randomized trials have shown that carotid endarterectomy (CEA) significantly reduces the 5-year risk of stroke in patients with 60-99 % asymptomatic stenoses (absolute risk reduction [ARR] 4.1% over 5 years, number needed to treat [NNT] 24) or 50-99% symptomatic stenoses (50-69%: ARR 4.6 % over 5 years, NNT 22; 70-99%: 15.9 % over 5 years, NNT 6). With the aid of intensive conservative treatment, the carotid artery-associated risk of stroke can be reduced to as little as 1% per year. Critical determination of indications and strict quality criteria are therefore necessary for CEA and carotid artery stenting (CAS). Systematic reviews of controlled trials comparing CEA and CAS show that the procedural risk of stroke is higher for CAS (asymptomatic: 2.6% versus 1.3%; symptomatic: 6.2% versus 3.8%). There are no differences in the long term. CEA is recommended as standard procedure for high-grade asymptomatic and moderate to high-grade symptomatic carotid artery stenoses; CAS may be considered as an alternative. For both procedures, the periprocedural combined rate of stroke or death should not exceed 2% for asymptomatic stenoses or 4% for symptomatic stenoses.

CONCLUSION

Future studies should evaluate even better selection criteria for optimal individualized treatment, whether conservative, surgical, or endovascular.

Rapid progression of carotid stenosis was rare in a large integrated healthcare system during an eight-year period

OBJECTIVE

Few studies have evaluated the rapid progression of carotid stenosis on a large scale. We created a custom software algorithm to analyze an electronic medical record database to examine the natural progression of carotid stenosis, identify a subset of patients with rapid progression, and evaluate the specific patient risk factors associated with this rapid progression.

METHODS

Patients in a large integrated healthcare system who had undergone two or more carotid ultrasound scans from August 2010 to August 2018 were identified. We did not distinguish between those with an established carotid stenosis diagnosis and those with a screening ultrasound scan. We used our novel algorithm to extract data from their carotid ultrasound reports. The degrees of carotid stenosis were categorized as follows: level 1, 0% to 39%; level 2, 40% to 59%; level 3, 60% to 79%; level 4, 80% to 99%; and level 5, complete occlusion. The primary endpoint was rapid vs slow progression of carotid stenosis, with rapid progression defined as an increase of two or more levels within any 18-month period of the study, regardless of the date of the initial ultrasound scan. The association of the demographic and clinical characteristics with rapid progression was assessed by univariable and multivariable logistic regression.

RESULTS

From a cohort of 4.4 million patients, we identified 4982 patients with two or more carotid ultrasound scans and a median follow-up period of 13.1 months (range, 0.1-93.7 months). Of the 4982 patients, 879 (17.6%) had shown progression of carotid stenosis. Only 116 patients (2.3%) had had progression to level 4 (80%-99% stenosis) from any starting level during a median of 11.5 months. A total of 180 patients (3.6%) were identified as experiencing rapid progression during a median follow-up of 9.9 months. The final multivariable analysis showed that younger age (P < .01), white race (P = .02), lower body mass index (P = .01), a diagnosis of peripheral arterial disease (P = .03), and a diagnosis of transient ischemic attack (P < .01) were associated with rapid progression.

CONCLUSIONS

Using a novel algorithm to extract data from >4 million patient records, we found that rapid progression of carotid stenosis appears to be rare. Although 17.6% of patients showed any degree of progression, only 3.6% had experienced rapid progression. Among those with any disease progression, 20.5% had experienced rapid progression. Although the overall incidence of rapid progression was low, patients with any progression might warrant close follow-up, especially if they have the associated risk factors for rapid progression. The custom software algorithm might be a powerful tool for creating and evaluating large datasets.

The conundrum of asymptomatic carotid stenosis-determinants of decision and evidence

Management of asymptomatic carotid disease continues to challenge medical practice and present evidence is often conflicting. Stroke is a significant burden in Public Health and 11% to 15% appear as first neurologic event associated with asymptomatic carotid stenosis. Randomized trials provided support for Guidelines and Recommendations to intervene on asymptomatic stenosis, but at a known cost of a high number of unnecessary operations. Conflicting evidence from natural history studies and the widespread use of proper medical management including risk factors control, lowering-lipid drugs and strict control of arterial hypertension have reduced the incidence of strokes associated to asymptomatic carotid disease challenging established practice. Need to identify vulnerable lesions prone to develop thromboembolic brain events and also vulnerable patients at a higher risk of stroke is necessary and essential to further improve effectiveness of our interventions. After review of published literature on natural history of asymptomatic carotid stenosis, diagnostic methods to identify plaque vulnerability and present-day results of both endarterectomy and stenting, a strategy for management of asymptomatic carotid stenosis is suggested aiming to reduce unnecessary interventions and effectively contribute to stroke prevention.

Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study: what have we learned from it?

The Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study is the largest natural history study on patients with 50–99% asymptomatic carotid stenosis (ACS). It included 1,121 ACS individuals with a follow-up between 6 and 96 months (mean: 48 months). During the last 15 years, several important ACSRS substudies have been published that have contributed significantly to the optimal management of ACS patients. These studies have demonstrated that specific baseline clinical characteristics and ultrasonic plaque features after image normalization (namely carotid plaque type, gray scale median, carotid plaque area, juxtaluminal black area without a visible echogenic cup, discrete white areas in an echolucent part of a plaque, silent embolic infarcts on brain computed tomography scans, a history of contralateral transient ischemic attacks/strokes) can independently predict future ipsilateral cerebrovascular events. The ACSRS study provided proof that by use of a computer program to normalize plaque images and extract plaque texture features, a combination of features can stratify patients into various categories depending on their stroke risk. The present review will discuss the various reported predictors of future ipsilateral cerebrovascular events and how these characteristics can be used to calculate individual stroke risk.

Evaluation of the interrater and intermethod agreement of the German multiparametric ultrasound criteria for the grading of internal carotid artery stenosis

PURPOSE

The interdisciplinary German guidelines for the diagnosis and treatment of internal carotid artery stenosis (ICAS) recommend a multiparametric approach for the sonographic grading of extracranial ICAS. The aim of this study is to evaluate the interrater and intermethod agreement of this elaborated sonographic approach with different angiographic modalities.

METHODS

Patients with extracranial ICAS were examined twice with colour-coded duplex sonography (CDS) by two experienced vascular neurologists. Each of the ten criteria and the resulting stenotic value were assessed. Grading of ICAS based on the multiparametric ultrasound criteria was compared with different angiography modalities (magnetic resonance angiography (MRA), computed tomography angiography (CTA), digital subtraction angiography (DSA)).

RESULTS

Seventy-four consecutive patients with 91 extracranial ICAS were recruited from our stroke unit and neurovascular outpatient clinic. Interrater agreement for each single ultrasound criterion ranged from moderate to excellent (for the peak systolic velocity). Concerning the absolute stenotic value of ICAS, an excellent agreement between both ultrasound examiners with an ICC of 0.91 (range 0.87-0.94; p < 0.001) was found. In 96% of ICAS, the difference between the stenotic values was ≤ 10%. Intermethod agreements between CDS and DSA, CTA, and MRA were also good for both sonographers.

CONCLUSION

Strictly adhering to the multiparametric "DEGUM ultrasound criteria", we found an excellent interrater agreement and a good intermethod agreement compared with angiography for the sonographic grading of extracranial ICAS. Thus, multiparametric CDS is in particular suitable for the follow up of extracranial ICAS even when examinations are done by different sonographers.

[Diagnostic and Therapeutic Management of Carotid Artery Disease]

Diagnostic and Therapeutic Management of Carotid Artery Disease Abstract. A quarter of all ischemic strokes is caused by atherosclerotic obliterations of the extra- and intracranial brain-supplying vessels. The prevalence of atherosclerotic extracranial carotid stenosis rises up to 6-15 % from the age of 65. The risk of stroke in symptomatic carotid stenosis, i.e. after stroke or transient ischemic attack (TIA), is very high at 25 % within 14 days. Conservative therapy is the cornerstone of treatment by controlling the risk factors, treatment with platelet aggregation inhibitors and antihypertensive and lipid-lowering medication. Carotid endarterectomy (CEA) is the first line treatment for symptomatic patients with a >50 % and asymptomatic patients with a >60 % carotid stenosis. In order to ensure the best possible treatment of patients with asymptomatic and symptomatic carotid stenosis, interdisciplinary cooperation in diagnostics, therapy and aftercare in a neuromedical centre of maximum care is necessary.

Carotid Revascularization: Current Practice and Future Directions

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.