Severity of Asymptomatic Carotid Stenosis and Risk of Ipsilateral Hemispheric Ischaemic Events: Results from the ACSRS Study

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.

Cilostazol-based dual antiplatelet treatment in ischemic stroke or transient ischemic attack patients with asymptomatic carotid artery disease: a propensity score matching analysis

Background

The optimal treatment for asymptomatic atherosclerotic carotid artery disease remains controversial. Data on the efficacy of antiplatelet agents and stroke outcomes are limited. This study aimed to examine the efficacy and safety of cilostazol-based dual antiplatelet therapy in patients with ischemic stroke or transient ischemic attack and asymptomatic carotid artery disease.

Methods

This retrospective cohort study was conducted in a tertiary-care setting and included baseline characteristics and clinical outcomes of participants. The study included patients who had experienced first-ever ischemic stroke or transient ischemic attack and asymptomatic atherosclerotic carotid artery stenosis, with a minimum follow-up period of 1 year. Asymptomatic carotid artery stenosis refers to stenosis in patients without neurological symptoms referable to the carotid arteries. Propensity scores were estimated using a logistic regression model based on participants' baseline characteristics. The efficacy outcome was the composite outcome of recurrent ischemic events and vascular-related death in patients with ischemic stroke or transient ischemic attack and asymptomatic carotid artery stenosis. The safety outcome was the occurrence of hemorrhagic complications such as intracranial hemorrhages or extracranial hemorrhages. The effectiveness of dual therapy compared to monotherapy was evaluated at various time points following the initiation of antiplatelet treatment.

Results

This study included 516 patients with a 1-year follow-up period. At 1 year, composite events occurred in 10 (6.3%) patients in the dual antiplatelet group compared with 12 (7.6%) in the single antiplatelet group (HR, 0.74; 95% CI, 0.61-0.90; p = 0.024). Extracranial hemorrhage occurred in 12 (7.6%) patients in the dual antiplatelet group compared with nine (5.7%) in the single antiplatelet group (HR, 1.35; 95% CI, 1.13-1.48; p = 0.017). No intracranial hemorrhages were observed in this cohort.

Conclusion

Patients with asymptomatic carotid artery stenosis who received cilostazol-based dual antiplatelet therapy had a lower risk of composite events but a higher risk of minor extracranial hemorrhage than those who received a single antiplatelet agent.

Detection rates of asymptomatic carotid artery stenosis and atrial fibrillation by selective screening of patients without cardiovascular disease

BACKGROUND

Individuals with significant asymptomatic carotid artery stenosis (ACAS) and atrial fibrillation (AF) could benefit from specific interventions to prevent heart attack and stroke, but are often clinically 'silent'. We aimed to determine detection rate of ACAS and AF by screening, targeting a population at increased cardiovascular risk.

METHODS

Data on adults who attended voluntary and self-funded commercial screening clinics in the United States or the United Kingdom between 2008 and 2013 were used. The Atherosclerotic Cardiovascular Disease (ASCVD) risk equation was applied to each participants and detection rates of targeted screening for ≥50% ACAS and AF to those at highest risk of CVD was assessed.

RESULTS

Among 0.4 million individuals between 40 and 80 years, without CVD, 6191 (1.6%) had ACAS and 1026 (0.3%) had AF. Selective screening of participants with a predicted 10-year CVD risk of ≥20% identified 40% of ACAS cases, a prevalence of 3.7%, leading to a number needed to screen (NNS) of 27, as well as 39% of AF cases, a prevalence of 0.6%, with a NNS of 170. Selective screening of those with a predicted 10-year CVD risk of ≥15% identified 54% of ACAS cases, a prevalence of 3.3%, and an NNS of 31, as well as 51% of AF cases, a prevalence of 0.5%, with an NNS of 195.

CONCLUSIONS

Selective screening for ACAS and AF implemented in ASCVD risk assessment greatly reduces the NNS when compared with population-level screening with detection rates of ACAS and AF substantially greater in people at higher predicted CVD risk.

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.

Medical and Surgical Management of Symptomatic and Asymptomatic Carotid Artery Stenosis: A Comprehensive Literature Review

Carotid artery stenosis is a condition where the carotid artery is blocked by fatty cholesterol deposits called plaque, increasing the risk of stroke. Elderly individuals with high cardiovascular risk are more susceptible, along with smokers, those with high cholesterol, males, and older individuals. Young females may also be affected by fibromuscular dysplasia. Carotid stenosis significantly raises stroke risk, and the severity is closely linked to stroke incidence and other cardiovascular events. Early detection and treatment are essential to prevent complications. Treatment options include medical and surgical interventions, such as carotid endarterectomy (CEA) and carotid artery stenting (CAS). The choice between surgery and medical management varies depending on patient characteristics and risk factors. This review explores carotid artery stenosis pathophysiology, risk factors, the importance of early detection and treatment, and the surgical approaches of CEA and CAS, addressing their roles and controversies. Healthcare professionals must understand these aspects to provide optimal care to patients with this condition.

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 Stenting for Asymptomatic Carotid Stenosis: What We Need to Know for Treatment Decision

A clinical decision on the treatment of asymptomatic carotid stenosis is challenging, unlike symptomatic carotid stenosis. Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (CEA) based on the finding that the efficacy and safety of CAS were comparable to CEA in randomized trials. However, in some countries, CAS is often performed more frequently than CEA for asymptomatic carotid stenosis. Moreover, it has been recently reported that CAS is not superior to the best medical treatment in asymptomatic carotid stenosis. Due to these recent changes, the role of CAS in asymptomatic carotid stenosis should be revisited. When determining the treatment for asymptomatic carotid stenosis, one should consider several clinical factors including stenosis degree, patient life expectancy, stroke risk by medical treatment, availability of a vascular surgeon, high risk for CEA or CAS, and insurance coverage. This review aimed to present and pragmatically organize the information that is necessary for a clinical decision on CAS in asymptomatic carotid stenosis. In conclusion, although the traditional benefit of CAS is being revisited recently, it seems too early to conclude that CAS is no longer beneficial under intense and systemic medical treatment. Instead, a treatment strategy with CAS should evolve to select eligible or medically high-risk patients more precisely.

Dengzhan Shengmai capsule versus Aspirin in the treatment of carotid atherosclerotic plaque: A single-centre, non-inferiority, prospective, randomised controlled trial

BACKGROUND

Aspirin is an effective antiplatelet agent for the treatment of carotid atherosclerosis. However, the high risk of bleeding events associated with the drug makes it necessary to seek a safer alternative, with similar or more efficacy than aspirin. Dengzhan Shengmai (DZSM) capsules have been widely used to treat carotid atherosclerosis, and if proven to be non-inferior to aspirin, it may be preferable over the latter for carotid atherosclerosis treatment due to its numerous advantages. We conducted a randomised trial to test the non-inferiority of DZSM to aspirin for the treatment of carotid atherosclerotic plaques.

METHODS

We performed a single-centre, prospective, open-label, randomised non-inferiority trial. Patients with carotid atherosclerotic plaques were enrolled and randomly assigned (1:1) to receive either DZSM capsules or aspirin. The follow-up period was 12 months. The primary outcome was the mean change in carotid intima-media thickness (IMT). Secondary outcomes included ischaemic events, rate of lumen stenosis, lipid levels, and plaque scores, length, counts, and vulnerability. Adverse events and laboratory test results were recorded as safety outcomes. The non-inferiority of DZSM was demonstrated when the lower limit of the one-sided 97.5% confidence interval (CI) of the difference in IMT between groups was more than -0.06 mm (margin of non-inferiority). This trial has been registered at ClinicalTrials.gov (CHiCTR1900021365).

RESULTS

From 1 April 2019 to 30 September 2019, 150 patients were enrolled, and there was no statistical difference in demographics between the groups. Intention-to-treat analysis showed that the decrease in IMT(_∆IMT) was 0.216 ± 0.160 and 0.225 ± 0.149 mm in the DZSM and aspirin groups, respectively. The one-sided 97.5% CI for the difference between _∆IMTs was (-0.0593, +∞). The non-inferiority of DZSM was demonstrated (P_{non-inferiority} = 0.0234). There was no significant difference in the incidence of ischaemic events between the groups (P = 1.0). The DZSM group had significantly reduced plaque scores (P < 0.0001), length (P < 0.0001), and counts (P < 0.0001), and improved plaque vulnerability (P < 0.0001). The DZSM group also had reduced levels of low-density lipoprotein cholesterol (LDL-C) (P < 0.0001). Finally, the DZSM group had a lower incidence of total adverse events (14.7% vs. 28%, P = 0.046), especially gastrointestinal discomfort (5.3% vs. 16%, P = 0.034). Although there was no significant difference in bleeding events (0 vs. 5.3%, P = 0.120), the DZSM group tended to have a lower incidence.

CONCLUSION

This trial demonstrated that DZSM was not inferior, in efficacy, to aspirin in treating carotid atherosclerotic plaques, and was found to be superior to aspirin in terms of safety. This study provides a new approach for treating carotid plaques, especially in aspirin-intolerant patients.

Retinal microvasculature and cerebral hemodynamics in patients with internal carotid artery stenosis

Purpose

To investigate the relationship between retinal microvasculature and cerebral hemodynamics in patients with internal carotid artery (ICA) stenosis.

Methods

Patients with unilateral moderate or severe ICA stenosis(≥50%) from West China hospital, Sichuan university were consecutively and prospectively recruited enrolled in the current study. En face angiograms of the superficial vascular complex (SVC), deep vascular complex (DVC), superficial vascular plexus (SVP), intermediate capillary plexus (ICP), and deep capillary plexus (DCP) were generated by automatic segmentation using swept-source optical coherence tomography angiography (SS-OCTA) to assess the retinal microvascular perfusion. The cerebral blood flow perfusion on bilateral middle cerebral artery territories measured at the basal ganglia level was assessed by brain computed tomography perfusion (CTP). CTP data were postprocessed to generate maps of different perfusion parameters including cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), mean transit time (MTT) and permeability surface(PS). Relative perfusion parameters (rPS, rCBF, etc.) were calculated as the ratio of the value on the contralateral side to that on the ipsilateral side.

Results

In the final analysis, 31 patients were included, of whom 11 patients had a moderate ICA stenosis (50–69%) and 20 with a severe ICA stenosis(≥70%). A total of 55 eyes were analyzed in the study, 27 eyes from the ipsilateral side (ie, side with stenosis) and 28 eyes from the contralateral side. In the patients with ICA stenosis, there was a strong correlation between the retinal microvascular perfusion of SVC with rCBV(B = 0.45, p = 0.03), rCBF(B = 0.26, p = 0.02) and rPS(B = 0.45, p < 0.001) after adjustment for age, sex and vascular risk factors. Similar correlations were also found between microvasculature in SVP and cerebral perfusion changes. There were no any significant associations of microvascular perfusion in both DVC and DCP with CTP parameters(all p > 0.05).

Conclusions

Retinal perfusion changes in superficial vascular layer (SVC and SVP) were correlated with brain hemodynamic compromise in patients with unilateral moderate or severe ICA stenosis(≥50%). Given the limited size of our study, future studies with larger sample size are needed to confirm our findings.

Carotid endarterectomy or stenting or best medical treatment alone for moderate-to-severe asymptomatic carotid artery stenosis: 5-year results of a multicentre, randomised controlled trial

BACKGROUND

The optimal treatment for patients with asymptomatic carotid artery stenosis is under debate. Since best medical treatment (BMT) has improved over time, the benefit of carotid endarterectomy (CEA) or carotid artery stenting (CAS) is unclear. Randomised data comparing the effect of CEA and CAS versus BMT alone are absent. We aimed to directly compare CEA plus BMT with CAS plus BMT and both with BMT only.

METHODS

SPACE-2 was a multicentre, randomised, controlled trial at 36 study centres in Austria, Germany, and Switzerland. We enrolled participants aged 50-85 years with asymptomatic carotid artery stenosis at the distal common carotid artery or the extracranial internal carotid artery of at least 70%, according to European Carotid Surgery Trial criteria. Initially designed as a three-arm trial including one group for BMT alone (with a randomised allocation ratio of 2·9:2·9:1), the SPACE-2 study design was amended (due to slow recruitment) to become two substudies with two arms each comparing CEA plus BMT with BMT alone (SPACE-2a) and CAS plus BMT with BMT alone (SPACE-2b); in each case in a 1:1 randomisation. Participants and clinicians were not masked to allocation. The primary efficacy endpoint was the cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years. The primary safety endpoint was any stroke or death from any cause within 30 days after CEA or CAS. The primary analysis was by intention-to treat, which included all randomly assigned patients in SPACE-2, SPACE-2a, and SPACE-2b, analysed using meta-analysis of individual patient data. We did two-step hierarchical testing to first show superiority of CEA and CAS to BMT alone then to assess non-inferiority of CAS to CEA. Originally, we planned to recruit 3640 patients; however, the study had to be stopped prematurely due to insufficient recruitment. This report presents the primary analysis at 5-year follow-up. This trial is registered with ISRCTN, number ISRCTN78592017.

FINDINGS

513 patients across SPACE-2, SPACE-2a, and SPACE-2b were recruited and surveyed between July 9, 2009, and Dec 12, 2019, of whom 203 (40%) were allocated to CEA plus BMT, 197 (38%) to CAS plus BMT, and 113 (22%) to BMT alone. Median follow-up was 59·9 months (IQR 46·6-60·0). The cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years (primary efficacy endpoint) was 2·5% (95% CI 1·0-5·8) with CEA plus BMT, 4·4% (2·2-8·6) with CAS plus BMT, and 3·1% (1·0-9·4) with BMT alone. Cox proportional-hazard testing showed no difference in risk for the primary efficacy endpoint for CEA plus BMT versus BMT alone (hazard ratio [HR] 0·93, 95% CI 0·22-3·91; p=0·93) or for CAS plus BMT versus BMT alone (1·55, 0·41-5·85; p=0·52). Superiority of CEA or CAS to BMT was not shown, therefore non-inferiority testing was not done. In both the CEA group and the CAS group, five strokes and no deaths occurred in the 30-day period after the procedure. During the 5-year follow-up period, three ipsilateral strokes occurred in both the CAS plus BMT and BMT alone group, with none in the CEA plus BMT group.

INTERPRETATION

CEA plus BMT or CAS plus BMT were not found to be superior to BMT alone regarding risk of any stroke or death within 30 days or ipsilateral stroke during the 5-year observation period. Because of the small sample size, results should be interpreted with caution.

FUNDING

German Federal Ministry of Education and Research (BMBF) and German Research Foundation (DFG).

High Stroke Rate in Patients With Medically Managed Asymptomatic Carotid Stenosis at an Academic Center in the Southeastern United States

BACKGROUND

Although the publication of randomized clinical trials defining the benefit of carotid endarterectomy (CEA) for asymptomatic carotid stenosis, medical management of carotid stenosis has changed significantly. With antiplatelet agents and statins, some question whether these trials are still relevant, suggesting that asymptomatic patients with >70% internal carotid artery (ICA) stenosis may do better with medial management alone, lessening the need for CEA and carotid stenting. The Vascular Quality Initiative (VQI) registry has shown that there are wide practice variations regarding the degree of stenosis that prompts surgical intervention but there are few reports of outcomes in patients who do not undergo intervention. We sought to determine the clinical outcomes of the >70% carotid stenosis patients who are treated with medical management alone at our institution.

METHODS

We identified all patients with ICA stenosis >70% based on hemodynamic consensus criteria (peak systolic velocity >230 cm/s) in our peripheral vascular laboratory from January 2013 through December 2016. With a retrospective chart review, demographics, comorbid conditions, medications, radiographic studies, clinical follow-up, interventions, and outcomes at 2 years were included. Descriptive statistics were used to define these variables.

RESULTS

One hundred and seventy three patients were identified with medically managed asymptomatic >70% ICA stenosis based on hemodynamic criteria on duplex ultrasound. The mean age was 67.5 years, 49% were male, 64% were White, 14% were Black, 13% race was undisclosed, 89% were prescribed antiplatelet therapy, 85% were prescribed a statin, and 60% had hypertension controlled to <140/90. Twenty patients (11.5%) experienced a cerebrovascular event during the 2-year study period. There were eight patients with transient ischemic attack, 10 with ipsilateral strokes, and 2 with strokes in unrelated territories.

CONCLUSIONS

Despite good adherence to current recommendations for medical therapy, patients at our institution are developing symptomatic carotid disease at a rate similar to that reported in historical clinical trials. These data supports the concept that advances in medical management have not resulted in reduced stroke rates in asymptomatic patients with high-grade carotid stenosis at a large academic institution located in the southeastern United States. CEA and stenting provide a significant risk reduction and should be considered more often in this patient population.

Guideline on carotid surgery for stroke prevention: updates from the Italian Society of Vascular and Endovascular Surgery. A trend towards personalized medicine

BACKGROUND

This guideline (GL) on carotid surgery as updating of "Stroke: Italian guidelines for Prevention and Treatment" of the ISO-SPREAD Italian Stroke Organization-Group, has recently been published in the National Guideline System and shared with the Italian Society of Vascular and Endovascular Surgery (SICVE) and other Scientific Societies and Patient's Association.

METHODS

GRADE-SIGN version, AGREE quality of reporting checklist. Clinical questions formulated according to the PICO model. Recommendations developed based on clinical questions by a multidisciplinary experts' panel and patients' representatives. Systematic reviews performed for each PICO question. Considered judgements filled by assessing the evidence level, direction, and strength of the recommendations.

RESULTS

The panel provided indications and recommendations for appropriate, comprehensive, and individualized management of patients with carotid stenosis. Diagnostic and therapeutic processes of the best medical therapy, carotid endarterectomy (CEA), carotid stenting (CAS) according to the evidences and the judged opinions were included. Symptomatic carotid stenosis in elective and emergency, asymptomatic carotid stenosis, association with ischemic heart disease, preoperative diagnostics, types of anesthesia, monitoring in case of CEA, CEA techniques, comparison between CEA and CAS, post-surgical carotid restenosis, and medical therapy are the main topics, even with analysis of uncertainty areas for risk-benefit assessments in the individual patient (personalized medicine [PM]).

CONCLUSIONS

This GL updates on the main recommendations for the most appropriate diagnostic and medical-surgical management of patients with atherosclerotic carotid artery stenosis to prevent ischemic stroke. This GL also provides useful elements for the application of PM in good clinical practice.

Carotid plaque surface echogenicity predicts cerebrovascular events: An Echographic Multicentric Swiss Study

BACKGROUND AND PURPOSE

To determine the prognostic value for ischemic stroke or transitory ischemic attack (TIA) of plaque surface echogenicity alone or combined to degree of stenosis in a Swiss multicenter cohort METHODS: Patients with ≥60% asymptomatic or ≥50% symptomatic carotid stenosis were included. Grey-scale based colour mapping was obtained of the whole plaque and of its surface defined as the regions between the lumen and respectively 0-0.5, 0-1, 0-1.5, and 0-2 mm of the outer border of the plaque. Red, yellow and green colour represented low, intermediate or high echogenicity. Proportion of red color on surface (PRCS) reflecting low echogenictiy was considered alone or combined to degree of stenosis (Risk index, RI).

RESULTS

We included 205 asymptomatic and 54 symptomatic patients. During follow-up (median/mean 24/27.7 months) 27 patients experienced stroke or TIA. In the asymptomatic group, RI ≥0.25 and PRCS ≥79% predicted stroke or TIA with a hazard ratio (HR) of respectively 8.7 p = 0.0001 and 10.2 p &lt; 0.0001. In the symptomatic group RI ≥0.25 and PRCS ≥81% predicted stroke or TIA occurrence with a HR of respectively 6.1 p = 0.006 and 8.9 p = 0.001. The best surface parameter was located at 0-0.5mm. Among variables including age, sex, degree of stenosis, stenosis progression, RI, PRCS, grey median scale values and clinical baseline status, only PRCS independently prognosticated stroke (p = 0.005).

CONCLUSION

In this pilot study including patients with at least moderate degree of carotid stenosis, PRCS (0-0.5mm) alone or combined to degree of stenosis strongly predicted occurrence of subsequent cerebrovascular events.

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.

Contralateral Stenosis and Echolucent Plaque Morphology are Associated with Elevated Stroke Risk in Patients Treated with Asymptomatic Carotid Artery Stenosis within a Controlled Clinical Trial (SPACE-2)

BACKGROUND

Asymptomatic carotid artery stenosis (ACS) has a low risk of stroke. To achieve an advantage over noninterventional best medical treatment (BMT), carotid endarterectomy (CEA) or carotid artery stenting (CAS) must be performed with the lowest possible risk of stroke. Therefore, an analysis of risk-elevating factors is essential. Grade of ipsilateral and contralateral stenosis as well as plaque morphology are known risk factors in ACS.

METHODS

The randomized, controlled, multicenter SPACE-2 trial had to be stopped prematurely after recruiting 513 patients. 203 patients were randomized to CEA, 197 to CAS, and 113 to BMT. Within one year, risk factors such as grade of stenosis and plaque morphology were analyzed.

RESULTS

Grade of contralateral stenosis (GCS) was higher in patients with any stroke (50%^ECST vs. 20%^ECST; p=0.012). Echolucent plaque morphology was associated with any stroke on the day of intervention (OR 5.23; p=0.041). In the periprocedural period, any stroke was correlated with GCS in the CEA group (70%^ECST vs. 20%^ECST; p=0.026) and with echolucent plaque morphology in the CAS group (6% vs. 1%; p=0.048). In multivariate analysis, occlusion of the contralateral carotid artery (CCO) was associated with risk of any stroke (OR 7.00; p=0.006), without heterogeneity between CEA and CAS.

CONCLUSION

In patients with asymptomatic carotid artery stenosis, GCS, CCO, as well as echolucent plaque morphology were associated with a higher risk of cerebrovascular events. The risk of stroke in the periprocedural period was increased by GCS in CEA and by echolucent plaque in CAS. Due to small sample size, results must be interpreted carefully.

Review of imaging biomarkers for the vulnerable carotid plaque

Identification of carotid artery atherosclerosis is conventionally based on measurements of luminal stenosis. However, histopathologic studies demonstrate considerable differences between plaques with identical degrees of stenosis and indicate that certain plaque features are associated with increased risk for ischemic events. As a result of the rapid technological evolution in medical imaging, several important steps have been taken in the field of carotid plaque imaging allowing us to visualize the carotid atherosclerotic plaque and its composition in great detail. For computed tomography, magnetic resonance imaging, positron emission tomography, and ultrasound scan, evidence has accumulated on novel imaging-based markers that confer information on carotid plaque vulnerability, such as intraplaque hemorrhage and lipid-rich necrotic cores. In terms of the imaging-based identification of individuals at high risk of stroke, routine assessments of such imaging markers are the way forward for improving current clinical practice. The current review highlights the main characteristics of the vulnerable plaque indicating their role in the etiology of ischemic stroke as identified by intensive plaque imaging.

Selective Nonoperative and Delayed Management of Severe Asymptomatic Carotid Artery Stenosis

OBJECTIVES

Although intervention is generally the standard of care for severe (80-99%) asymptomatic carotid stenosis, conservative management may be appropriate for a subset of patients. Our goal was to assess reasons for and outcomes of nonoperative/delayed operative management of asymptomatic severe carotid stenosis.

METHODS

Institutional vascular laboratory data from 2010 to 2018 was queried for all patients who underwent a carotid duplex ultrasonography. Patients with severe asymptomatic carotid stenosis (80-99%) were included. Such stenosis was defined by an end diastolic velocity >140 cm/sec on duplex ultrasound in patients without transient ischemic attacks (TIA)/strokes ≤6 months prior to imaging. Nonoperative/delayed operative management was defined as not undergone carotid endarterectomy (CEA) or carotid artery stent (CAS) ≤6 months after imaging. Reasons for nonoperative management or delayed intervention as well as subsequent TIA/stroke and survival were determined. Kaplan-Meier analysis was performed to evaluate survival.

RESULTS

Among 211 patients with severe carotid stenosis, 35 (16.6%) were managed nonoperatively or with delayed operation. Mean age in this subset was 72.6 ± 11.4 years and the majority were female (57.1%), had a smoking history (74.3%), and were on statins (91.4%) at the time of index duplex ultrasound. Reasons for no/delayed intervention were classified as severe medical comorbidities (37.1%), advanced age (17.1%), no referral for intervention (14.3%), patient refusal (14.3%), other severe concomitant cerebrovascular disease (11.4%), and active/advanced cancer (5.7%). Over a median follow-up of 35.2 months, no patients experienced TIAs/strokes attributable to carotid stenosis. One patient had a multifocal bilateral stroke after a cardiac arrest and prolonged resuscitation. A subset of patients underwent delayed CEA (8.6%) or CAS (2.9%). Four-year survival after initial imaging was 79%.

CONCLUSIONS

Reasons for nonoperative and delayed operative management in our cohort of asymptomatic carotid stenosis were commonly due to comorbidities and advanced age. However, a subset of patients was never referred to vascular surgeons/interventionalists. Adverse neurologic events due to carotid stenosis were not observed during follow-up and patients had relatively high long-term survival.

Management of carotid stenosis for primary and secondary prevention of stroke: state-of-the-art 2020: a critical review

Carotid atherosclerotic plaque is encountered frequently in patients at high cardiovascular risk, especially in the elderly. When plaque reaches 50% of carotid lumen, it induces haemodynamically significant carotid stenosis, for which management is currently at a turning point. Improved control of blood pressure, smoking ban campaigns, and the widespread use of statins have reduced the risk of cerebral infarction to <1% per year. However, about 15% of strokes are still secondary to a carotid stenosis, which can potentially be detected by effective imaging techniques. For symptomatic carotid stenosis, current ESC guidelines put a threshold of 70% for formal indication for revascularization. A revascularization should be discussed for symptomatic stenosis over 50% and for asymptomatic carotid stenosis over 60%. This evaluation should be performed by ultrasound as a first-line examination. As a complement, computed tomography angiography (CTA) and/or magnetic resonance angiography are recommended for evaluating the extent and severity of extracranial carotid stenosis. In perspective, new high-risk markers are currently being developed using markers of plaque neovascularization, plaque inflammation, or plaque tissue stiffness. Medical management of patient with carotid stenosis is always warranted and applied to any patient with atheromatous lesions. Best medical therapy is based on cardiovascular risk factors correction, including lifestyle intervention and a pharmacological treatment. It is based on the tri-therapy strategy with antiplatelet, statins, and ACE inhibitors. The indications for carotid endarterectomy (CEA) and carotid artery stenting (CAS) are similar: for symptomatic patients (recent stroke or transient ischaemic attack ) if stenosis >50%; for asymptomatic patients: tight stenosis (>60%) and a perceived high long-term risk of stroke (determined mainly by imaging criteria). Choice of procedure may be influenced by anatomy (high stenosis, difficult CAS or CEA access, incomplete circle of Willis), prior illness or treatment (radiotherapy, other neck surgery), or patient risk (unable to lie flat, poor AHA assessment). In conclusion, neither systematic nor abandoned, the place of carotid revascularization must necessarily be limited to the plaques at highest risk, leaving a large place for optimized medical treatment as first line management. An evaluation of the value of performing endarterectomy on plaques considered to be at high risk is currently underway in the ACTRIS and CREST 2 studies. These studies, along with the next result of ACST-2 trial, will provide us a more precise strategy in case of carotid stenosis.

Personalized-medicine on carotid endarterectomy and stenting

Evidence based medicine (EBM) is the core of current clinical guidelines and is considered as the gold standard of clinical practice. Despite this, a number of limitations and criticisms are moved to EBM. The major one is that this method privileges randomized controlled trials (RCTs), in which the selection of patients is often based on rigid inclusion criteria. The lack of “pragmatism” of some RCTs sometimes makes it difficult to apply guidelines that derive from them to patients observed in clinical practice, who are often affected by comorbidities and disabilities. The new paradigm to overcome this limitation is personalized medicine (PM), which aims to take into account the particular characteristics displayed by the individual. In order to tailor the best treatment for the patient, PM uses EBM but emphasizes the person's specific information from the assessment of the clinic, lifestyle and risk/benefit scores. This narrative review tries to find the best evidence by analysing subgroups and risk scores of patients from meta-analysis and RCTs in order to try to apply PM and to provide good practice points (GPP) on grey aspects and open questions not fully covered by current guidelines on carotid endarterectomy (CEA) and stenting for stroke prevention.

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.

Natural History of Non-operative Management in Asymptomatic Patients with 70%-80% Internal Carotid Artery Stenosis by Duplex Criteria

OBJECTIVE

Treatment of asymptomatic internal carotid artery (ICA) stenosis, particularly for moderate to severe (70%-80%) disease, is controversial. The goal was to assess the clinical course of patients with moderate to severe carotid stenosis.

METHODS

A single institution retrospective analysis of patients with asymptomatic ICA stenosis identified on duplex ultrasound as moderate to severe (70%-80%) from 2003 to 2018 were analysed. Duplex criteria for 70%-80% stenosis was a systolic velocity of ≥325 cm/s or an ICA:common carotid artery ratio of ≥4, and an end diastolic velocity of <140 cm/s. Asymptomatic status was defined as no stroke/transient ischaemic attack (TIA) within six months of index duplex. Primary outcomes were progression of stenosis to >80%, ipsilateral stroke/TIA without documented progression, and death.

RESULTS

In total, 206 carotid arteries were identified in 182 patients meeting the inclusion criteria. Mean patient age was 71.5 years, 57.7% were male, and 67% were white. There were 19 stenoses removed from analysis except for survival analysis as they initially underwent carotid endarterectomy or carotid artery stent based on surgeon/patient preference. Documented progression occurred in 24.1% of stenoses. There were 5.3% of stenoses associated with an ipsilateral stroke/TIA without documented progression, which occurred at a mean of 26.4 months. Kaplan-Meier analysis demonstrated a 60.3% five year freedom from stenosis progression, 92.5% five year freedom from stroke/TIA without documented progression, and 83.7% five year survival. Risk factors associated with stroke/TIA without documented progression at five years were atrial fibrillation (hazard ratio [HR] 14.87, 95% confidence interval [CI] 2.72-81.16; p = .002) and clopidogrel use at index duplex (HR 6.19, 95% CI 1.33-28.83; p = .020). Risk factors associated with death at five years were end stage renal disease (HR 9.67, 95% CI 2.05-45.6; p = .004), atrial fibrillation (HR 7.55, 95% CI 2.48-23; p < .001), prior head/neck radiation (HR 6.37, 95% CI 1.39-29.31; p = .017), non-obese patients (HR 5.49, 95% CI 1.52-20; p = .009), and non-aspirin use at index duplex (HR 3.05, 95% CI 1.12-8.33; p = .030).

CONCLUSION

Patients with asymptomatic moderate to severe carotid stenosis had a low rate of stroke/TIA without documented progression. However, there was a high rate of stenosis progression reinforcing the need to follow these patients closely.

[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.

Asymptomatic carotid intraplaque hemorrhage is associated with a high risk of cerebral infarction and death after cardiovascular surgery

BACKGROUND

There is a lack of information on the natural history of asymptomatic carotid artery stenosis (AsymCS) associated with cardiovascular diseases that require surgery. The aim of this study was to investigate risk factors for postoperative ipsilateral ischemic stroke and all-cause mortality after cardiovascular surgery in patients with AsymCS.

METHODS

Among 2158 patients who underwent cardiovascular surgery, 150 patients with AsymCS who didn't undergo carotid revascularization were included. The relationships between preoperative factors, including carotid intraplaque hemorrhage (IPH), and postoperative ipsilateral ischemic stroke and all-cause mortality were analyzed retrospectively.

RESULTS

During the median follow-up of 1087 days of 150 patients with 19 IPH, 12 (8.0%) and 21 (14.0%) encountered ipsilateral infarction and all-cause mortality, respectively. Multivariable Cox regression analyses indicated that IPH was significantly predictive of both ipsilateral infarction (hazard ratio [HR] 21.31, 95% confidence interval [CI], 4.98-91.17; P ≤.001) and all-cause mortality (HR 4.64, 95% CI, 1.61-13.34; P = .004). Another significant factor was peak systolic velocity for ipsilateral infarction with the cutoff velocity of 227 cm/s by the receiver-operating characteristic curve.

CONCLUSIONS

In this cohort of patients with AsymCS undergoing cardiovascular surgery, IPH had a close connection with a high risk of both postoperative ischemic stroke and mortality after cardiovascular surgery.

Validation of Risk Prediction Models to Detect Asymptomatic Carotid Stenosis

Background Significant asymptomatic carotid stenosis (ACS) is associated with higher risk of strokes. While the prevalence of moderate and severe ACS is low in the general population, prediction models may allow identification of individuals at increased risk, thereby enabling targeted screening. We identified established prediction models for ACS and externally validated them in a large screening population. Methods and Results Prediction models for prevalent cases with ≥50% ACS were identified in a systematic review (975 studies reviewed and 6 prediction models identified [3 for moderate and 3 for severe ACS]) and then validated using data from 596 469 individuals who attended commercial vascular screening clinics in the United States and United Kingdom. We assessed discrimination and calibration. In the validation cohort, 11 178 (1.87%) participants had ≥50% ACS and 2033 (0.34%) had ≥70% ACS. The best model included age, sex, smoking, hypertension, hypercholesterolemia, diabetes mellitus, vascular and cerebrovascular disease, measured blood pressure, and blood lipids. The area under the receiver operating characteristic curve for this model was 0.75 (95% CI, 0.74-0.75) for ≥50% ACS and 0.78 (95% CI, 0.77-0.79) for ≥70% ACS. The prevalence of ≥50% ACS in the highest decile of risk was 6.51%, and 1.42% for ≥70% ACS. Targeted screening of the 10% highest risk identified 35% of cases with ≥50% ACS and 42% of cases with ≥70% ACS. Conclusions Individuals at high risk of significant ACS can be selected reliably using a prediction model. The best-performing prediction models identified over one third of all cases by targeted screening of individuals in the highest decile of risk only.

Misconceptions regarding the adequacy of best medical intervention alone for asymptomatic carotid stenosis

BACKGROUND

Medical intervention (risk factor identification, lifestyle coaching, and medication) for stroke prevention has improved significantly. It is likely that no more than 5.5% of persons with advanced asymptomatic carotid stenosis (ACS) will now benefit from a carotid procedure during their lifetime. However, some question the adequacy of medical intervention alone for such persons and propose using markers of high stroke risk to intervene with carotid endarterectomy (CEA) and/or carotid angioplasty/stenting (CAS). Our aim was to examine the scientific validity and implications of this proposal.

METHODS

We reviewed the evidence for using medical intervention alone or with additional CEA or CAS in persons with ACS. We also reviewed the evidence regarding the validity of using commonly cited makers of high stroke risk to select such persons for CEA or CAS, including markers proposed by the European Society for Vascular Surgery in 2017.

RESULTS

Randomized trials of medical intervention alone versus additional CEA showed a definite statistically significant CEA stroke prevention benefit for ACS only for selected average surgical risk men aged less than 75 to 80 years with 60% or greater stenosis using the North American Symptomatic Carotid Endarterectomy Trial criteria. However, the most recent measurements of stroke rate with ACS using medical intervention alone are overall lower than for those who had CEA or CAS in randomized trials. Randomized trials of CEA versus CAS in persons with ACS were underpowered. However, the trend was for higher stroke and death rates with CAS. There are no randomized trial results related to comparing current optimal medical intervention with CEA or CAS. Commonly cited markers of high stroke risk in relation to ACS lack specificity, have not been assessed in conjunction with current optimal medical intervention, and have not been shown in randomized trials to identify those who benefit from a carotid procedure in addition to current optimal medical intervention.

CONCLUSIONS

Medical intervention has an established role in the current routine management of persons with ACS. Stroke risk stratification studies using current optimal medical intervention alone are the highest research priority for identifying persons likely to benefit from adding a carotid procedure.

Management of Asymptomatic Carotid Artery Stenosis

PURPOSE OF REVIEW

The goal of this paper is to provide the reader with a review of the evidence supporting the surgical and medical management of patients with asymptomatic internal carotid artery (ICA) stenosis.

RECENT FINDINGS

Based on the results of earlier clinical trials, surgical intervention with carotid endarterectomy (CEA) has long been the preferred method of management for patients with asymptomatic severe carotid stenosis. Carotid artery stenting (CAS) is another less invasive surgical option that has similar outcomes over the long-term. However, more recent improvements in medical management have reduced the risk of stroke in this population to comparable rates seen with CEA. As a result, medical management alone is advocated as well for patients with asymptomatic carotid stenosis. In addition to stenosis severity, there are a number of features of plaque morphology associated with vulnerable plaque that predict future stroke risk. Rates of stroke in patients with asymptomatic severe carotid stenosis with modern surgical techniques, CEA and CAS, are similar to modern medical therapy alone. Both surgery and medical therapy are good treatment options but it is not known which treatment is superior. The Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2), an NIH-sponsored, multicenter, randomized trial that aims to answer this important management decision.

Comparing the feasibility and accuracy of three-dimensional ultrasound to two-dimensional ultrasound and computed tomography angiography in the assessment of carotid atherosclerosis

AIMS

Two-dimensional ultrasound (2D-US) is the mainstay imaging technique used to evaluate carotid atherosclerosis. An automated single sweep three-dimensional ultrasound (3D-US) technique became available. We evaluated the feasibility and accuracy of 3D-US in the assessment of carotid plaques compared to those of 2D-US. Carotid computed tomography angiography (CTA) was used as a reference.

METHODS AND RESULTS

Among 126 stroke patients who underwent carotid 2D-US, 73 underwent 3D-US and carotid CTA. 3D-US was pursued when there were carotid plaques or when area stenosis was ≥ 20% by 2D-US. Both 2D- and 3D-US images of the carotid arteries were acquired using a dedicated ultrasound system that was equipped with the single sweep volumetric transducer. In total, 266 arteries from 73 patients were selected for comparison of the detection rate of carotid plaques between 2D- and 3D-US. Among the 73 patients, carotid CTA detected 139 plaques. 3D-US demonstrated a higher detection rate of carotid plaques than did 2D-US (108 plaques (77.9%) vs. 70 plaques (50.4%)) when using carotid CTA as a reference standard. Carotid plaque volume (PV) of 133 vessels from 73 patients were quantitatively evaluated using both 3D-US and carotid CTA. Plaque volume of carotid artery was comparable between 3D-US and CTA (148.5 ± 133.0 mm³ vs. 154.1 ± 134.6 mm³ , P = .998, R: 0.9825, P-value for r < .001).

CONCLUSION

3D-US using a single sweep technique was a feasible and accurate method of detecting arterial plaques and assessing plaque volume.

Outcomes for carotid endarterectomy in nonagenarians

OBJECTIVE

Carotid endarterectomy (CEA) is a well-established procedure with prospective randomized data demonstrating the benefit of stroke prevention. With the aging of the population, there are limited data published for nonagenarians, especially for asymptomatic stenosis. This study investigated 30-day morbidity and mortality as well as late survival in symptomatic and asymptomatic nonagenarians with severe carotid stenosis undergoing CEA.

METHODS

A retrospective review was conducted of a single vascular surgery group's registry involving multiple hospitals between November 1994 and June 2017 for all primary CEAs of patients ≥90 years old at the time of surgery. The exclusion criterion was redo surgery or bilateral CEAs. Demographic data, sex, symptoms, risk factors, and postoperative complications were analyzed. Survival analysis was conducted using SPSS software (IBM Corp, Armonk, NY) for the specific end point 30-day morbidity or mortality and late survival.

RESULTS

There were 77 patients (44 male [57%]) who underwent CEA for symptomatic (44 [57%]) and asymptomatic (33 [43%]) internal carotid artery stenosis with a median age of 92 years; 23 women were symptomatic compared with 21 men, and 23 men were asymptomatic compared with 10 women. Symptomatic patients included amaurosis fugax (n = 3), stroke (n = 16), and transient ischemic attack (n = 25). CEAs were performed using the eversion technique under cervical block with selective shunting. The 30-day morbidity included one (2.3%) nonfatal myocardial infarction and one (2.3%) ischemic stroke in the symptomatic group compared with one (3%) patient having a nonfatal myocardial infarction and none with ischemic stroke in the asymptomatic group. One patient of the symptomatic group required return to the operating room for hematoma evacuation. The 30-day mortality was 2.3% in the symptomatic group compared with 6.1% in the asymptomatic group. There was no statistical difference in survival based on sex (P = .444). The symptomatic and asymptomatic groups had similar median survival of 27.7 months and 29.4 months (P = .987), respectively.

CONCLUSIONS

The aging population adds increasing difficulty in decision-making for surgical intervention on carotid stenosis. CEA in nonagenarians is associated with reasonably low 30-day rates of ischemic stroke and myocardial infarction in our small study. However, enthusiasm for asymptomatic CEA in this population must be tempered by low survival rates.

Symptomatic vs. Asymptomatic 20-40% Internal Carotid Artery Stenosis: Does the Plaque Size Matter?

Background: Around 9–15% of ischemic strokes are related to internal carotid artery (ICA)-stenosis ≥50%. However, the extent to which ICA-stenosis <50% causes ischemic cerebrovascular events is uncertain. We examined the relation between plaque cross-sectional area and length and the risk of ischemic stroke or TIA among patients with ICA-stenosis of 20–40%.

Methods: We retrospectively identified patients admitted to the Department of Neurology, University Hospital of Würzburg, from January 2011 until September 2016 with ischemic stroke or TIA and concomitant ICA-stenosis of 20–40%, either symptomatic or asymptomatic. Plaque length and cross-sectional area were assessed on ultrasound scans.

Results: We identified 41 patients with ischemic stroke or TIA and ICA-stenosis of 20–40%; 14 symptomatic and 27 asymptomatic. The plaque cross-sectional area was significantly larger among symptomatic than asymptomatic ICA-stenosis; median values (IQR) were 0.45 (0.21–0.69) cm² and 0.27 (0.21–0.38) cm², p = 0.03, respectively. A plaque cross-sectional area ≥0.36 cm² had a sensitivity of 71% and a specificity of 76% for symptomatic compared with asymptomatic ICA-stenosis. In a sex-adjusted multivariate logistic regression, a plaque cross-sectional area ≥0.36 cm² and a plaque length ≥1.65 cm were associated with an OR (95% CI) of 5.54 (1.2–25.6), p = 0.028 and 1.78 (0.36–8.73), p = 0.48, respectively, for symptomatic ICA-stenosis.

Conclusion: Large plaques might increase the risk of ischemic stroke or TIA among patients with low-grade ICA-stenosis of 20–40%. Sufficiently powered prospective longitudinal cohort studies are needed to definitively test the stroke risk stratification value of carotid plaque length and cross-sectional area in the setting of current optimal medical treatment.

Ultrasound-based carotid stenosis measurement and risk stratification in diabetic cohort: a deep learning paradigm

BACKGROUND

Stroke is in the top three leading causes of death worldwide. Non-invasive monitoring of stroke can be accomplished via stenosis measurements. The current conventional image-based methods for these measurements are not accurate and reliable. They do not incorporate shape and intelligent learning component in their design.

METHODS

In this study, we propose a deep learning (DL)-based methodology for accurate measurement of stenosis in common carotid artery (CCA) ultrasound (US) scans using a class of AtheroEdge system from AtheroPoint, USA. Three radiologists manually traced the lumen-intima (LI) for the near and the far walls, respectively, which served as a gold standard (GS) for training the DL-based model. Three DL-based systems were developed based on three types of GS.

RESULTS

IRB approved (Toho University, Japan) 407 US scans from 204 patients were collected. The risk was characterized into three classes: low, moderate, and high-risk. The area-under-curve (AUC) corresponding to three DL systems using receiver operating characteristic (ROC) analysis computed were: 0.90, 0.94 and 0.86, respectively.

CONCLUSIONS

Novel DL-based strategy showed reliable, accurate and stable stenosis severity index (SSI) measurements.

[Some comments on the 2017 European Guidelines on treatment of atherosclerotic lesions of brachiocephalic arteries]

Analysed herein are the indications for primary interventions in patients with atherosclerotic lesions of internal carotid arteries according to the recommendations laid down in the 2017 Guidelines of the European Society for Vascular Surgery.

Identifying asymptomatic patients at high-risk for stroke

Carotid endarterectomy and carotid artery stenting, in addition to good medical therapy, halve long-term stroke risk in asymptomatic patients with carotid artery stenosis. Since the absolute benefits following successful intervention are moderate, identification of asymptomatic patients at high-risk of future stroke could maximize the effectiveness of carotid interventions. The aim of this paper is to summarize the evidence for high-risk features associated with increased long-term stroke risk in asymptomatic patients. There is a paucity of reliable data describing the effect of clinical features, imaging findings and plaque characteristics on increased long-term stroke risk. Clinical and imaging features such as contralateral symptoms, silent brain infarcts/embolic signals, progression of stenosis and impaired cerebrovascular reactivity may be associated with increased future risk of stroke. Plaque characteristics such as echolucency, large plaque size (≥80 mm), intra-plaque hemorrhage, lipid-rich necrotic core and thinned/ruptured fibrous cap may also increase future risk of stroke. Whilst these form the basis for European guidelines targeting carotid intervention in asymptomatic patients with tight stenosis, conclusive evidence of their utility is lacking. Results from ongoing large, multicenter randomized clinical trials comparing carotid endarterectomy and carotid artery stenting with good medical therapy may be consistent with earlier trials, showing a halving of the long-term risk of stroke following successful carotid revascularization. However, they may well lack sufficient statistical power to identify higher-risk subgroups in whom the absolute gains of treatment are significantly higher. Large contemporary cohort studies are needed to provide further clarity regarding high-risk features associated with increased long-term stroke risk in asymptomatic patients with carotid artery stenosis.

Relative Cerebral Blood Transit Time Decline and Neurological Improvement in Patients After Internal Carotid Artery Stenting

In this study we hypothesized that the alleviation of neurological symptoms long after internal carotid artery (ICA) stenting may be related to sustained improvement of cerebral perfusion. Thirty-four subjects (F/M; 15/19) with >70% stenosis of a single internal carotid artery and neurological symptoms, who underwent a carotid artery stenting procedure, were studied. Brain computed tomography perfusion (CTP) imaging was performed before and 3 years after ICA stenting. The following relative variables were compared: cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), time to peak (rTTP), and permeability surface area product (rPS). A survey also was conducted to compare the patients' clinical symptoms. Overall, we found that a trend toward rMTT decline was the only persisting change after ICA stenting. We then stratified the patients into the subgroups of <2%, 2-5%, and > 5% rMTT decline and found that those with a rMTT decline >2% reported a prominent reduction in subjective clinical symptoms such as headache, dizziness, tinnitus, blurred vision, transient blindness, a sense of gravity of the head, and pain in the eyeballs. We conclude that a shortened mean rMTT, likely reflecting improved cerebral microcirculation, underlies the improvement of neurological symptoms in patients with ICA stenosis.

Contemporary Management of Patients with Concomitant Coronary and Carotid Artery Disease

The ideal management of concomitant carotid and coronary artery occlusive disease remains elusive. Although researchers have advocated the potential benefits of varying treatment strategies based on either concomitant or staged surgical treatment, there is no consensus in treatment guidelines among national or international clinical societies. Clinical studies show that coronary artery bypass grafting (CABG) with either staged or synchronous carotid endarterectomy (CEA) is associated with a high procedural stroke or death rate. Recent clinical studies have found carotid artery stenting (CAS) prior to CABG can lead to superior treatment outcomes in asymptomatic patients who are deemed high risk of CEA. With emerging data suggesting favorable outcome of CAS compared to CEA in patients with critical coronary artery disease, physicians must consider these diverging therapeutic options when treating patients with concurrent carotid and coronary disease. This review examines the available clinical data on therapeutic strategies in patients with concomitant carotid and coronary artery disease. A treatment paradigm for considering CAS or CEA as well as CABG and percutaneous coronary intervention is discussed.

Recent Advances in Primary and Secondary Prevention of Atherosclerotic Stroke

Atherosclerosis is a major cause of ischemic stroke that can be effectively prevented with appropriate lifestyle modifications and control of cardiovascular risk factors. Medical advances in recent years along with aggressive cardiovascular risk factor modifications have resulted in decreased recurrence rates of atherosclerotic stroke. Non-statin lipid-lowering molecules have recently shown clinical benefit and are recommended for very high-risk patients to reduce their risk of stroke. Aggressive hypertension treatment is crucial to reduce atherosclerotic stroke risk. Advances in antithrombotic treatments include combinations of antiplatelets and new antiplatelet agents in the acute phase post-stroke, which carries a high risk of recurrence. Intensive medical treatment has also limited the indications for carotid interventions, especially for asymptomatic disease. Intracranial atherosclerotic disease may provoke stroke through various mechanisms; it is increasingly recognized as a cause of ischemic stroke with advanced imaging and is best managed with lifestyle modifications and medical therapy. The diagnostic search for the vulnerable culprit atherosclerotic plaque is an area of intense research, from the level of the intracranial arteries to that of the aortic arch. Ultrasonography and novel magnetic resonance imaging techniques (high-resolution vessel-wall imaging) may assist in the identification of vulnerable atherosclerotic plaques as the underlying cause in cryptogenic or misdiagnosed non-atherosclerotic ischemic stroke. Vertebrobasilar atherosclerotic disease is less common than carotid artery disease; thus, high-quality data on effective prevention strategies are scarcer. However, aggressive medical treatment is also the gold standard to reduce cerebrovascular disease located in posterior circulation.

Imaging vulnerable plaques by targeting inflammation in atherosclerosis using fluorescent-labeled dual-ligand microparticles of iron oxide and magnetic resonance imaging

OBJECTIVE

Identification of patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and a prelude to clinical sequelae. There are currently no clinical imaging tools to assess the inflammatory activity within plaques. This study characterized inflammation in atherosclerosis using dual-targeted microparticles of iron oxide (DT-MPIO) as a magnetic resonance imaging (MRI) probe.

METHODS

DT-MPIO were used to detect and characterize inflammatory markers, vascular cell adhesion molecule 1 (VCAM-1). and P-selectin on (1) tumor necrosis factor-α-treated cells by immunocytochemistry and (2) aortic root plaques of apolipoprotein-E deficient mice by in vivo MRI. Furthermore, apolipoprotein E-deficient mice with focal carotid plaques of different phenotypes were developed by means of periarterial cuff placement to allow in vivo molecular MRI using these probes. The association between biomarkers and the magnetic resonance signal in different contrast groups was assessed longitudinally in these models.

RESULTS

Immunocytochemistry confirmed specificity and efficacy of DT-MPIO to VCAM-1 and P-selectin. Using this in vivo molecular MRI strategy, we demonstrated (1) the DT-MPIO-induced magnetic resonance signal tracked with VCAM-1 (r = 0.69; P = .014), P-selectin (r = 0.65; P = .022), and macrophage content (r = 0.59; P = .045) within aortic root plaques and (2) high-risk inflamed plaques were distinguished from noninflamed plaques in the murine carotid artery within a practical clinical imaging time frame.

CONCLUSIONS

These molecular MRI probes constitute a novel imaging tool for in vivo characterization of plaque vulnerability and inflammatory activity in atherosclerosis. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid atherosclerotic disease in the future.

Clinical Effect and Cost-Effectiveness of Screening for Asymptomatic Carotid Stenosis: A Markov Model

OBJECTIVE/BACKGROUND

The cost-effectiveness of screening depends on the cost of screening, prevalence of asymptomatic carotid artery stenosis (ACAS), and the potential effect of medical intervention in reducing the risk of stroke. The aim of the study was to determine the threshold values for these parameters in order for screening for ACAS to be cost-effective.

METHODS

The clinical effect and cost-effectiveness of ultrasound screening for ACAS with subsequent initiation of preventive therapy versus not screening was assessed in a Markov model with a lifetime perspective. Key parameters, including stroke risk, all cause mortality, and costs, were based on contemporary published data, population statistics, and data from an ongoing screening program in Uppsala county (population 300,000), Sweden. Prevalence of ACAS (2%) and the rate of best medical treatment (BMT; 40%) were based on data from a male Swedish population recently screened for ACAS. The required stroke risk reduction from BMT, incremental cost-efficiency ratio (ICER), absolute risk reduction for stroke (ARR), and number needed to screen (NNS) were calculated.

RESULTS

Screening was cost-effective at an ICER of €5744 per incremental quality adjusted life year (QALY) gained. ARR was 135 per 100,000 screened, NNS was 741, and QALYs gained were 6700 per 100,000 invited. At a willingness to pay (WTP) threshold of €50,000 per QALY the minimum required stroke risk reduction from BMT was 22%. The assumed degree of stroke risk reduction was the most important determinant of cost-efficiency.

CONCLUSION

A moderate (22%) reduction in the risk of stroke was required for an ACAS screening strategy to be cost-effective at a WTP of €50,000/QALY. Targeting populations with a higher prevalence of ACAS could further improve cost-efficiency.

Which patients with asymptomatic carotid stenosis benefit from revascularization?

PURPOSE OF REVIEW

To summarize why there are polarized opinions regarding the management of patients with asymptomatic carotid disease and whether it is possible to identify patients who might benefit from carotid interventions.

RECENT FINDINGS

Carotid Revascularization Endarterectomy Versus Stenting Trial and Asymptomatic Carotid Trial 1 (ACT-1) recently concluded that outcomes after carotid endarterectomy and carotid stenting were not significantly different in asymptomatic patients and that procedural risks were below the accepted 3% threshold. However, systematic reviews suggest that Carotid Revascularization Endarterectomy Versus Stenting Trial/ACT-1 results may not be generalizable into routine practice. In parallel, meta-analyses suggest that stroke rates on medical therapy may be declining, suggesting that Asymptomatic Carotid Atherosclerosis Study/Asymptomatic Carotid Surgery Trial data, which have underpinned every practice guideline since 1995, are too historical for use in 2017. A recent review has, however, identified a number of clinical/imaging features that may be associated with higher rates of stroke on medical therapy.

SUMMARY

The majority of surgeons/interventionists are unlikely to accept radical changes in practice until new randomized trials confirm that the risk of stroke on modern medical therapy is significantly lower than that previously accepted. In the interim, it would be preferable to target interventions into a smaller cohort who present with clinical/imaging features that might render them 'higher risk for stroke' on medical therapy.

Ultrasonographical Features Associated with Progression of Atherosclerosis in Patients with Moderate Internal Carotid Artery Stenosis

Carotid artery stenosis (CAS) is a leading cause of ischemic stroke. Plaque stabilization is a major management approach. Information about the ultrasonographical and clinical features associated with the progression of moderate internal carotid artery (ICA) stenosis (50-69%) could assist with prognostication and risk factor modifications. We evaluated 287 patients with moderate ICA stenosis (50-69%) and subsequently evaluated them at follow-up points at 12, 24, and 36 months. Patients were divided into three groups according to the degree of ICA stenosis: progression (70-99%, n = 48), stable (50-69%, n = 210), and regression (< 50%, n = 29). Responsible plaque thickness (RPT) across groups during follow-up was compared using a repeated measure ANOVA test. An ordinal regression was subsequently applied to identify risk factors for atherosclerosis progression. Male (P = 0.04), hypoechoic plaque (P < 0.01), smoking (P = 0.02), plaque ulceration (P = 0.05), and contralateral severe CAS or occlusions (P = 0.04) on ultrasound was more frequent in the progression group vs. other two groups. The ordinal regression revealed that only hypoechoic plaque (OR, 7.03; 95% CI, 3.34-14.81; P < 0.01) and contralateral ICA severe stenosis or occlusion (OR, 2.86; 95% CI, 1.41-5.80; P < 0.01) were independently associated with stenosis progression, while statin use was inversely associated with stenosis progression (OR, 0.26; 95% CI, 0.13-0.54; P < 0.01). Of note, symptomatic vs. asymptomatic moderate CAS at baseline was not associated with progression. For patients with moderate CAS, hypoechoic plaque, contralateral severe stenosis or occlusion on ultrasonography, and statin use are independently related to stenosis progression. Statin use may delay the progression of carotid stenosis.