Evidence-Based Carotid Interventions for Stroke Prevention: State-of-the-art Review

Case report: Selective operative management of zone 3 carotid artery transection

INTRODUCTION

Penetrating carotid artery injury is rare and particularly uncommon in zone 3 of the vessel. Due to anatomical challenges to open operative management in zone 3, there are minimal treatment recommendations for this highly morbid condition. The urgency associated with understanding proper management of this traumatic injury is further supported by the nearly 100 % rate of fatality in untreated penetrating carotid artery injuries.

PRESENTATION OF CASE

A 17-year-old male presented with a bullet wound to the right temple. He was intubated for airway protection given left-sided tracheal deviation secondary to a right neck hematoma. His Glasgow Coma Scale (GCS) was 11 on initial presentation, E3V2M6. The patient remained hemodynamically stable and underwent a CT angiogram of the head and neck. Imaging revealed a complete transection of the cervical (zone III) right internal carotid artery (RICA), a large pseudoaneurysm of the RICA distal to carotid bifurcation, and comminuted mandibular fracture. Collateral blood flow was preserved to the right hemisphere. Multi-disciplinary discussions deemed risks of operative intervention outweighed the benefits in the immediate peri-trauma period as the increased risk of hemispheric stroke, exsanguination, and death was thought to be prohibitive. Therefore, treatment of delayed intervascular stenting of the RICA was performed as opposed to emergent open RICA ligation or repair.

DISCUSSION

Treatment decisions for zone 3 CAI rely on the patient's hemodynamic stability, with surgical ligation favored for immediate hemorrhage control in unstable cases, while stable patients may undergo observation or delayed endovascular intervention. Balancing the need for hemostasis to prevent further blood loss with the potential benefits of anticoagulation to maintain cerebral perfusion underscores the decision-making required in managing such cases.

CONCLUSION

The rarity and challenge of ICA injury at this anatomical location presents unique challenges. Our description of observation and delayed revascularization outlines the precarious, yet validated, treatment method for hemodynamically stable patients.

Risk factors of in-stent restenosis after carotid angioplasty and stenting: long-term follow-up study

Background

After carotid artery angioplasty with stenting (CAS), it is unclear which risk factors are related to long-term outcomes, including in-stent restenosis (ISR). This study aimed to assess the factors associated with restenosis after CAS with a median follow-up of 35.7 months.

Materials and methods

Patients who underwent CAS from January 2013 to December 2018 were included if they had symptomatic or asymptomatic carotid artery stenosis. The carotid Doppler ultrasonography (CDU) was followed up after the procedure. We defined at least 50% restenosis using the criteria that the internal carotid artery (ICA) peak systolic velocity (PSV) was greater than 224 cm/s or the ICA to common carotid artery PSV ratio was higher than 3.4. The risk factors for ISR were also assessed.

Results

Of the 189 patients, 122 had symptomatic carotid artery stenosis, and 67 had asymptomatic carotid artery stenosis. Patients were evaluated by CDU for a median of 35.7 months (interquartile range 19.5 to 70.0). Kaplan-Meier analysis showed that the longest time to ISR was 39 months, and ISR-free was better in the asymptomatic CAS group. In all groups, ISR was independently associated with current smoker [adjusted odds ratio (aOR), 3.425; 95% confidence interval (CI), 1.086 to 10.801] and elevated ICA PSV at baseline (aOR, 1.004; 95% CI, 1.001 to 1.007).

Conclusion

Independent risk factors for ISR in the CAS group included current smoking and elevated ICA PSV at baseline. In the symptomatic CAS group, alcohol was independently associated with the ISR. ISR did not occur after 39 months from the CAS procedure in our study patients. Future studies with extended follow-up are necessary to fully understand the long-term outcomes of CAS.

Investigating the Added Value of Beck's Depression Inventory in Atherosclerosis Prediction: Lessons from Paracelsus 10,000

Background: Depression is the most common mental illness worldwide and generates an enormous health and economic burden. Furthermore, it is known to be associated with an elevated risk of arteriosclerotic cardiovascular diseases (ASCVD), particularly stroke. However, it is not a factor reflected in many ASCVD risk models, including SCORE2. Thus, we analysed the relationship between depression, ASCVD and SCORE2 in our cohort. Methods: We analysed 9350 subjects from the Paracelsus 10,000 cohort, who underwent both a carotid artery ultrasound and completed a Beck Depression Inventory (BDI) screening. Patients were categorised binomially based on the BDI score. Atherosclerotic carotid plaque or absence was dichotomised for logistic regression modelling. Odds ratios and adjusted relative risks were calculated using Stata. Results: Subjects with an elevated BDI (≥14) had higher odds for carotid plaques compared to subjects with normal BDI, especially after adjusting for classical risk factors included in SCORE2 (1.21; 95%CI 1.03-1.43, p = 0.023). The adjusted relative risk for plaques was also increased (1.09; 95%CI 1.01-1.18, p = 0.021). Subgroup analysis showed an increased odds of plaques with increases in depressive symptoms, particularly in women and patients ≤55 yrs. Conclusions: In our cohort, the BDI score is associated with subclinical atherosclerosis beyond classical risk factors. Thus, depression might be an independent risk factor which may improve risk stratification if considered in ASCVD risk prediction models, such as SCORE2. Furthermore, reminding clinicians to take mental health into consideration to identify individuals at increased atherosclerosis risk may provide added opportunities to address measures which can reduce the risk of ASCVD.

Use of an embolic protection device during carotid artery stenting is associated with lower periprocedural risk

OBJECTIVE

To investigate associations between individual embolic protection device (EPD) use and respective center policy with periprocedural outcomes after carotid artery stenting (CAS).

METHODS

This analysis is based on the nationwide German statutory quality assurance database and was funded by Germany's Federal Joint Committee Innovation Fund (G-BA Innovationsfonds, 01VSF19016 ISAR-IQ). According to their policy towards EPD use, hospitals were categorized as routine EPD (>90%), selective EPD (10-90%), or sporadic EPD (<10%) centers. Primary study outcome was in-hospital stroke or death. Univariate and multivariate regression analyses were performed.

RESULTS

Overall, 19 302 patients who had undergone CAS between 2013 and 2016 were included. The highest in-hospital stroke or death rate was found in sporadic EPD centers, followed by selective and routine EPD centers (3.1% vs 2.9% vs 1.8%; P<0.001). Across the whole cohort, EPD use was associated with a lower in-hospital stroke or death rate (OR=0.60; 95% CI 0.50 to 0.72). In the multivariate regression analysis, EPD use was independently associated with a lower in-hospital stroke rate (aOR=0.66; 95% CI 0.46 to 0.94). Regarding center policy, routine EPD centers showed a significantly lower in-hospital mortality compared with sporadic EPD centers (aOR=0.44; 95% CI 0.22 to 0.88).

CONCLUSIONS

In a contemporary real-world cohort with low risk of selection bias, EPD use was associated with a lower in-hospital risk of stroke. A center policy of routine EPD use was associated with lower mortality. These data support routine use of EPD during CAS to enhance patient safety.

Cognitive effects of carotid revascularization in octogenarians

BACKGROUND

Cognitive impairment is the epitome of cerebrovascular diseases, causing a significant economic burden on our health care system. Growing evidence has indicated the benefits of carotid interventions in patients with severe carotid atherosclerosis. However, the neurocognitive outcome of carotid revascularization in octogenarians is not clearly understood. We aim to evaluate postintervention cognitive changes in seniors older than 80 years.

METHODS

We prospectively recruited 170 patients undergoing carotid interventions. Neurocognitive testing was performed preoperatively and at 1, 6, and 12 months postoperatively. Episodic memory was assessed with Rey's Auditory Verbal Learning Test. Other executive functions and language measures were also evaluated at individual time points. Raw test scores were converted to z-scores or scaled scores adjusted for age and education. The sample was divided into 2 groups based on age: octogenarian (≥80 years) and nonoctogenarian (<80 years old). Postoperative cognitive scores were compared to baseline within each subcohort.

RESULTS

A total of 23 subjects (13%) were octogenarians, and 147 (87%) were younger than 80 years. Younger patients demonstrated significant cognitive improvements up to 12 months postop compared to the baseline. However, octogenarians exhibited a lack of improvement in verbal memory, measures of executive function, and language at all 3 postintervention time points.

CONCLUSION

Carotid interventions improve cognitive functions in younger patients with carotid occlusive atherosclerosis. However, no cognitive benefits were seen in male seniors older than 80 years. Further investigations are warranted to better understand the postinterventional cognitive changes in octogenarians.

Ultrasonography Grading of Internal Carotid Artery Disease: Multiparametric German Society of Ultrasound in Medicine (DEGUM) versus Society of Radiologists in Ultrasound (SRU) Consensus Criteria

PURPOSE

 We sought to determine the diagnostic agreement between the revised ultrasonography approach by the German Society of Ultrasound in Medicine (DEGUM) and the established Society of Radiologists in Ultrasound (SRU) consensus criteria for the grading of carotid artery disease.

MATERIALS AND METHODS

 Post-hoc analysis of a prospective multicenter study, in which patients underwent ultrasonography and digital subtraction angiography (DSA) of carotid arteries for validation of the DEGUM approach. According to DEGUM and SRU ultrasonography criteria, carotid arteries were independently categorized into clinically relevant NASCET strata (normal, mild [1-49 %], moderate [50-69 %], severe [70-99 %], occlusion). On DSA, carotid artery findings according to NASCET were considered the reference standard.

RESULTS

 We analyzed 158 ultrasonography and DSA carotid artery pairs. There was substantial agreement between both ultrasonography approaches for severe (κw 0.76, CI95 %: 0.66-0.86), but only fair agreement for moderate (κw 0.38, CI95 %: 0.19-0.58) disease categories. Compared with DSA, both ultrasonography approaches were of equal sensitivity (79.7 % versus 79.7 %; p = 1.0) regarding the identification of severe stenosis, yet the DEGUM approach was more specific than the SRU approach (70.2 % versus 56.4 %, p = 0.0002). There was equality of accuracy parameters (p > 0.05) among both ultrasonography approaches for the other ranges of carotid artery disease.

CONCLUSION

 While the sensitivity was equivalent, false-positive identification of severe carotid artery stenosis appears to be more frequent when using the SRU ultrasonography approach than the revised multiparametric DEGUM approach.

Duplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments

BACKGROUND

Carotid artery stenosis is an important cause of stroke and transient ischemic attack. Correctly and rapidly identifying patients with symptomatic carotid artery stenosis is essential for adequate treatment with early cerebral revascularization. Doubts about the diagnostic value regarding the accuracy of duplex ultrasound (DUS) and the possibility of using DUS as the single diagnostic test before carotid revascularization are still debated.

OBJECTIVES

To estimate the accuracy of DUS in individuals with symptomatic carotid stenosis verified by either digital subtraction angiography (DSA), computed tomography angiography (CTA), or magnetic resonance angiography (MRA).

SEARCH METHODS

We searched CRDTAS, CENTRAL, MEDLINE (Ovid), Embase (Ovid), ISI Web of Science, HTA, DARE, and LILACS up to 15 February 2021. We handsearched the reference lists of all included studies and other relevant publications and contacted experts in the field to identify additional studies or unpublished data.

SELECTION CRITERIA

We included studies assessing DUS accuracy against an acceptable reference standard (DSA, MRA, or CTA) in symptomatic patients. We considered the classification of carotid stenosis with DUS defined with validated duplex velocity criteria, and the NASCET criteria for carotid stenosis measures on DSA, MRA, and CTA. We excluded studies that included < 70% of symptomatic patients; the time between the index test and the reference standard was longer than four weeks or not described, or that presented no objective criteria to estimate carotid stenosis.

DATA COLLECTION AND ANALYSIS

The review authors independently screened articles, extracted data, and assessed the risk of bias and applicability concerns using the QUADAS-2 domain list. We extracted data with an effort to complete a 2 × 2 table (true positives, true negatives, false positives, and false negatives) for each of the different categories of carotid stenosis and reference standards. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where meta-analysis was possible, we used a bivariate meta-analysis model.

MAIN RESULTS

We identified 25,087 unique studies, of which 22 were deemed eligible for inclusion (4957 carotid arteries). The risk of bias varied considerably across the studies, and studies were generally of moderate to low quality. We narratively described the results without meta-analysis in seven studies in which the criteria used to determine stenosis were too different from the duplex velocity criteria proposed in our protocol or studies that provided insufficient data to complete a 2 × 2 table for at least in one category of stenosis. Nine studies (2770 carotid arteries) presented DUS versus DSA results for 70% to 99% carotid artery stenosis, and two (685 carotid arteries) presented results from DUS versus CTA in this category. Seven studies presented results for occlusion with DSA as the reference standard and three with CTA as the reference standard. Five studies compared DUS versus DSA for 50% to 99% carotid artery stenosis. Only one study presented results from 50% to 69% carotid artery stenosis. For DUS versus DSA, for < 50% carotid artery stenosis, the summary sensitivity was 0.63 (95% confidence interval [CI] 0.48 to 0.76) and the summary specificity was 0.99 (95% CI 0.96 to 0.99); for the 50% to 69% range, only one study was included and meta-analysis not performed; for the 50% to 99% range, the summary sensitivity was 0.97 (95% CI 0.95 to 0.98) and the summary specificity was 0.70 (95% CI 0.67 to 0.73); for the 70% to 99% range, the summary sensitivity was 0.85 (95% CI 0.77 to 0.91) and the summary specificity was 0.98 (95% CI 0.74 to 0.90); for occlusion, the summary sensitivity was 0.91 (95% CI 0.81 to 0.97) and the summary specificity was 0.95 (95% CI 0.76 to 0.99). For sensitivity analyses, excluding studies in which participants were selected based on the presence of occlusion on DUS had an impact on specificity: 0.98 (95% CI 0.97 to 0.99). For DUS versus CTA, we found two studies in the range of 70% to 99%; the sensitivity varied from 0.57 to 0.94 and the specificity varied from 0.87 to 0.98. For occlusion, the summary sensitivity was 0.95 (95% CI 0.80 to 0.99) and the summary specificity was 0.91 (95% CI 0.09 to 0.99). For DUS versus MRA, there was one study with results for 50% to 99% carotid artery stenosis, with a sensitivity of 0.88 (95% CI 0.70 to 0.98) and specificity of 0.60 (95% CI 0.15 to 0.95); in the 70% to 99% range, two studies were included, with sensitivity that varied from 0.54 to 0.99 and specificity that varied from 0.78 to 0.89. We could perform only a few of the proposed sensitivity analyses because of the small number of studies included.

AUTHORS' CONCLUSIONS

This review provides evidence that the diagnostic accuracy of DUS is high, especially at discriminating between the presence or absence of significant carotid artery stenosis (< 50% or 50% to 99%). This evidence, plus its less invasive nature, supports the early use of DUS for the detection of carotid artery stenosis. The accuracy for 70% to 99% carotid artery stenosis and occlusion is high. Clinicians should exercise caution when using DUS as the single preoperative diagnostic method, and the limitations should be considered. There was little evidence of the accuracy of DUS when compared with CTA or MRA. The results of this review should be interpreted with caution because they are based on studies of low methodological quality, mainly due to the patient selection method. Methodological problems in participant inclusion criteria from the studies discussed above apparently influenced an overestimated estimate of prevalence values. Most of the studies included failed to precisely describe inclusion criteria and previous testing. Future diagnostic accuracy studies should include direct comparisons of the various modalities of diagnostic tests (mainly DUS, CTA, and MRA) for carotid artery stenosis since DSA is no longer considered to be the best method for diagnosing carotid stenosis and less invasive tests are now used as reference standards in clinical practice. Also, for future studies, the participant inclusion criteria require careful attention.

Multiple hypointense veins on susceptibility weighted imaging as a promising biomarker of impaired cerebral hemodynamics in chronic steno-occlusive disease: a multiparametric MRI study

PURPOSE

Patients with steno-occlusive arterial disease may develop cerebral hypoperfusion with possible neurologic sequelae. The aim of the study is to verify the possible role of SWI, as a marker of cerebral hypoperfusion, in the identification of patient subgroups with significant chronic occlusions/stenoses at risk of critical cerebral hypoperfusion.

METHODS

We retrospectively identified 37 asymptomatic patients with chronic intra-extracranial occlusion/stenosis of the anterior circulation from a prospective brain MRI register between 2016 and 2020. All patients underwent 3 Tesla MRI. The imaging protocol included the following: SWI, 3D-FLAIR, DWI sequences, and 3D-TOF MRA. SWI findings were graded for the presence of asymmetric intracranial cortical veins (grades 1 to 4). The presence of collateralization was assessed with concomitant multiphase-CTA. FLAIR was evaluated for the presence of distal hyperintense vessels (DHVs), a described marker of flow impairment, and possible collateralization. Cerebral blood flow and arterial transit artifacts (ATAs) were evaluated at pCASL in 29 patients.

RESULTS

SWI showed multiple hypointense vessels (MHVs) in 22/37 patients in the cerebral hemisphere ipsilateral to vessel occlusion/stenosis. SWI-MHV grade 1 was found in 15 patients (40.5%), grade 2 in 18 patients (48.7%), and grade 3 in 3 patients (8.1%); in one patient, SWI was graded as 4 (2.7%). A significant relationship was found among MHV, DHV, collaterals, ATAs, and hypoperfused areas on pCASL and with patients' previous neurological symptoms.

CONCLUSION

SWI-MVH correlates with chronic cerebral flow impairment and is related to hypoperfusion and collateralization. It may help identify a subgroup of patients benefitting from revascularization.

Carotid Endarterectomy

Stroke is the second leading cause of death worldwide. One of the main causes of stroke is carotid artery stenosis. Stenosis with atherosclerosis in the carotid artery can cause stroke by hemodynamic ischemia or artery to artery embolism. A most common surgical intervention for carotid artery stenosis is carotid endarterectomy (CEA). Many studies on CEA have been reported and suggested medical indications. For symptomatic carotid stenosis, generally, CEA may be indicated for patients with more than 50% stenosis and is especially beneficial in men, patients aged 75 years or older, and patients who underwent surgery within 2 weeks of their last symptoms. For asymptomatic carotid stenosis, CEA may be indicated for those with more than 60% stenosis, though each guideline has different suggestions in detail. In order to evaluate the indication for CEA in each case, it is important to assess risks for CEA carefully including anatomical factors and comorbidities, and to elaborate each strategy for each operation based on preoperative imaging studies including carotid ultrasonography, magnetic resonance imaging and angiography. In surgery there are many tips on operative position, procedure, shunt usage and monitoring to perform a safe and smooth operation. Now that carotid artery stenting has been rapidly developed, better understanding for CEA is required to treat carotid artery stenosis adequately. This chapter must be a good help to understand CEA well.

In Silico Hemodynamics and Filtering Evaluation of a Commercial Embolic Protection Device

During the last years, several kinds of Embolic Protection Devices (EPD) have been developed, with the aim of minimizing complication caused by thrombi generated during Carotid Artery Stenting (CAS). These devices are capable of capturing small particles generated during the intervention, avoiding cerebral stroke and improving the outcomes of the surgery. However, they have associated complications, like the increase on flow resistance associated by their use or the lack of knowledge on their actual filtration efficiency for thrombi of low size. Current work proposes a validated computational methodology in order to predict the hemodynamic features and filtering efficiency of a commercial EPD. It will be observed how Computational Fluid Dynamics predicts pressure drop with fair agreement with the experimental measurements. Finally, this work analyzes the filtration efficiency and the influence of the distribution of injected particles on this parameter. The capabilities of the filter for retaining particles of diameter below the pore size is, additionally, discussed.

Aortic Valve Sclerosis as an Important Predictor of Long-Term Mortality in Patients With Carotid Atheromatous Plaque Requiring Carotid Endarterectomy

Background: A strong association between aortic valve sclerosis (AVSc), the earliest manifestation of calcific aortic valve disease, and atherosclerosis exists. The aim of the study was to evaluate the predictive capabilities of AVSc on long-term all-cause mortality, in patients requiring carotid endarterectomy (CEA).

Methods and Results: 806 consecutive CEA patients were enrolled. Preoperative echocardiography was used to assess AVSc. Computed tomography angiography was applied for plaque characterization. Kaplan-Meier curves, Cox linear regression, and area under the receiving operator characteristic (AUC) curve analyses were used to evaluate the predictive capability of AVSc. Overall, 348 of 541 patients had AVSc (64%). Age, diabetes, and estimated glomerular filtration rate (eGFR) were associated with AVSc. In the 5-year follow-up, AVSc group had a mortality rate of 16.7% while in no-AVSc group was 7.8%. Independent predictors of all-cause mortality were age, sex, eGFR, left ventricular ejection fraction, and AVSc. After adjustments, AVSc was associated with a significant increase in all-cause mortality risk (hazard ratio, HR = 1.9; 95%CI: 1.04–3.54; p = 0.038). We stratify our cohort based on carotid atheromatous plaque-type: soft, calcified, and mixed-fibrotic. In patients with mixed-fibrotic plaques, the mortality rate of AVSc patients was 15.5% compared to 2.4% in no-AVSc patients. In this group, AVSc was associated with an increased long-term all-cause mortality risk with an adjusted HR of 12.8 (95%CI: 1.71–96.35; p = 0.013), and the AUC, combing eGFR and AVSc was 0.77 (p < 0.001).

Conclusions: Our findings indicate that AVSc together with eGFR may be used to improve long-term risk stratification of patients undergoing CEA surgery.

Functional MRI evaluation of the effect of carotid artery stenting: a case study demonstrating cognitive improvement

Background

The narrowing of the carotid arteries with plaque formation represents a major risk factor for ischemic stroke and cognitive impairments. Carotid angioplasty and stenting is a standard clinical treatment to reduce stroke risk. The cognitive effect of carotid angioplasty and stenting remains largely unknown.

Purpose

This study aims to provide direct evidence of possible effects of carotid angioplasty and stenting on cognition, using task-phase functional magnetic resonance imaging.

Material and Methods

This study received harmonized institutional ethics board approval (Grant number REB ID =H18-02495/FHREB 2018-058). Two patients had MRI scans pre-carotid angioplasty and stenting and two-month post-carotid angioplasty and stenting. Case 1 had severe (>95%) flow-limiting stenosis in the right carotid artery. Case 2 had 70% non-flow limiting stenosis in the left carotid artery. At each scan, patients completed two functional magnetic resonance imaging sessions while performing a working memory task. Accuracy, reaction time, and brain activation were analyzed for each patient for possible pre-post carotid angioplasty and stenting changes.

Results

Case 1 showed increased activation in the right (treated-side) frontal and temporal lobes post-carotid angioplasty and stenting; associated with improvements in accuracy (from 58% to 74%) and task completion rate (from 17% to 72%). Case 2 completed the tasks pre- and post-carotid angioplasty and stenting with >90% accuracy, while decreased functional magnetic resonance imaging activation in the contralateral (untreated) hemisphere and mildly increased activation in the left (treated -side) anterior circulation territory were observed post-carotid angioplasty and stenting.

Conclusion

These cases provided the first task-phase functional magnetic resonance imaging data demonstrating that carotid angioplasty and stenting improved cognitive function in the re-perfused vascular territory. The finding supports the role of carotid angioplasty and stenting in improving cognitive performance beyond reducing stroke risk.

Long-term imaging follow-up to evaluate restenosis in patients with carotid stenosis after angioplasty and stenting

BACKGROUND

Stent patency after carotid angioplasty and stenting (CAS) correlates not only with stroke prevention but also with improvements in cognition and quality of life by positively influencing cerebral perfusion. The long-term outcomes of CAS after more than 5 years have still not been well described. This retrospective study was designed to evaluate the stent patency and significant restenosis (SR) after CAS with more than 5 years of follow-up.

METHODS

Between 2006 and 2012, 118 patients with carotid stenosis who underwent 131 CAS procedures with regular annual imaging follow-up for more than 5 years were enrolled. We evaluated their demographic characteristics and the risk factors related to stent restenosis. Patients with SR (restenosis ≥ 50%) were compared with those with no significant restenosis (NSR, patency or restenosis < 50%) to identify the restenosis predictors and restenosis-free survival.

RESULTS

Of the 131 CAS procedures, 16.0% (21/131) had SR. A history of head and neck radiotherapy (HNRT) was a predictor for SR (HR, 6.352; 95% CI, 2.504-16.112; p < 0.001) and was associated with shorter restenosis-free survival (log-rank test p value < 0.001, median time of restenosis-free survival was 38 months). Left-sided stenting was an associated factor for SR (HR, 3.007; 95% CI, 1.068-8.467; p = 0.037) with a trend of less restenosis-free survival (log-rank test p value 0.067).

CONCLUSION

Both HNRT and left-sided carotid stenosis were predictors of SR after CAS in more than 5 years of long-term follow-up. Restenosis-free survival was significantly shorter in patients with prior HNRT than in patients without previous irradiation treatment. We suggest close follow-up and aggressive medical treatment for patients with prior HNRT and left-sided carotid stenosis undergoing CAS.

Auscultation System for Acquisition of Vascular Sounds - Towards Sound-Based Monitoring of the Carotid Artery

Introduction

Atherosclerotic diseases of the carotid are a primary cause of cerebrovascular events such as stroke. For the diagnosis and monitoring angiography, ultrasound- or magnetic resonance-based imaging is used which requires costly hardware. In contrast, the auscultation of carotid sounds and screening for bruits - audible patterns related to turbulent blood flow - is a simple examination with comparably little technical demands. It can indicate atherosclerotic diseases and justify further diagnostics but is currently subjective and examiner dependent.

Methods

We propose an easy-to-use computer-assisted auscultation system for a stable and reproducible acquisition of vascular sounds of the carotid. A dedicated skin-transducer-interface was incorporated into a handheld device. The interface comprises two bell-shaped structures, one with additional acoustic membrane, to ensure defined skin contact and a stable propagation path of the sound. The device is connected wirelessly to a desktop application allowing real-time visualization, assessment of signal quality and input of supplementary information along with storage of recordings in a database. An experimental study with 5 healthy subjects was conducted to evaluate usability and stability of the device. Five recordings per carotid served as data basis for a wavelet-based analysis of the stability of spectral characteristics of the recordings.

Results

The energy distribution of the wavelet-based stationary spectra proved stable for measurements of a particular carotid with the majority of the energy located between 3 and 40 Hz. Different spectral properties of the carotids of one individual indicate the presence of sound characteristics linked to the particular vessel. User-dependent parameters such as variations of the applied contact pressure appeared to have minor influence on the general stability.

Conclusion

The system provides a platform for reproducible carotid auscultation and the creation of a database of pathological vascular sounds, which is a prerequisite to investigate sound-based vascular monitoring.

Outcomes of Carotid Revascularization versus Optimal Medical Treatment Alone for Asymptomatic Carotid Stenosis: Inverse-Probability-of-Treatment Weighting Using Propensity Scores

BACKGROUND

The benefits and necessity of revascularization for asymptomatic carotid stenosis remains under debate. This study aimed to determine the more durable and beneficial alternative between carotid revascularization and optimal medical treatment (OMT) alone for asymptomatic carotid stenosis.

METHODS

We performed a retrospective analysis of patients with asymptomatic severe carotid stenosis at a tertiary institution between 1994 and 2017. We compared revascularization (carotid endarterectomy [CEA] and carotid artery stenting [CAS]) with OMT alone by using inverse-probability-of-treatment weighting with propensity scores to account for selection bias. The primary end point was a composite of any stroke, myocardial infarction, and death within 30 days, plus ipsilateral stroke thereafter.

RESULTS

A total of 1089 patients were included in the analysis (56% CEA, 25% CAS, 19% OMT alone). Patients who underwent CAS consistently showed greater risk regarding the primary composite end point compared with those who received OMT alone (hazard radio [HR] 3.32, 95% confidence interval 1.014-10.868; P = 0.047), but the CEA group showed no significant difference (HR 1.19, 95% confidence interval 0.385-4.584; P = 0.761). The CAS group had the greatest rates of any stroke within 30 days (4.0%, P = 0.0006) and ipsilateral stroke thereafter (3.68%, P = 0.0009). There was no death within 30 days. In the long-term outcomes, neither CEA nor CAS showed significant differences in HR compared with OMT alone.

CONCLUSIONS

Our study suggests that for stroke prevention in asymptomatic severe carotid stenosis, CAS might be inferior to the other 2 options regarding early outcomes. However, further investigation is required regarding the efficacy and durability of OMT alone.

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.

Recurrent versus first cervical artery dissection - a retrospective study of clinical and vascular characteristics

BACKGROUND AND PURPOSE

Most recurrent cervical artery dissection (CeAD) events occur shortly after the acute first CeAD. This study compared the characteristics of recurrent and first CeAD events and searched for associations between subsequent events of an individual person.

METHODS

Cervical artery dissection patients with a new CeAD event occurring during a 3-6 month follow-up were retrospectively selected in seven specialized stroke centers. Clinical and vascular characteristics of the initial and the recurrent CeADs were compared.

RESULTS

The study sample included 76 patients. Recurrent CeADs were occlusive in one (1.3%) patient, caused cerebral ischaemia in 13 (17.1%) and were asymptomatic in 39 (51.3%) patients, compared to 29 (38.2%) occlusive, 42 (55.3%) ischaemic and no asymptomatic first CeAD events. In 52 (68.4%) patients, recurrent dissections affected both internal carotid arteries or both vertebral arteries, whilst 24 (31.6%) patients had subsequent dissections in both types of artery. Twelve (28.6%) of 42 patients with an ischaemic first dissection had ischaemic symptoms due to the recurrent CeADs, too. However, only one (1.3%) of 34 patients with a non-ischaemic first CeAD suffered ischaemia upon recurrence.

CONCLUSION

Recurrent CeAD typically affects the same site of artery. It causes ischaemic events less often than the first CeAD. The risk that patients who presented with solely non-ischaemic symptoms of a first CeAD will have ischaemic symptoms in the case of a recurrent CeAD seems very small.

Role of 18F-FDG positron emission tomography in carotid atherosclerotic plaque imaging: A systematic review

Stroke and other thromboembolic events in the brain are often due to carotid artery atherosclerosis, and atherosclerotic plaques with inflammation are considered particularly vulnerable, with an increased risk of becoming symptomatic. Positron emission tomography (PET) with 2-deoxy-2-[Fluorine-18] fluoro-D-glucose (¹⁸F-FDG) provides valuable metabolic information regarding arteriosclerotic lesions and may be applied for the detection of vulnerable plaque. At present, however, patients are selected for carotid surgical intervention on the basis of the degree of stenosis alone, and not the vulnerability or inflammation of the lesion. During the past decade, research using PET with the glucose analog tracer ¹⁸F-fluor-deoxy-glucose, has been implemented for identifying increased tracer uptake in symptomatic carotid plaques, and tracer uptake has been shown to correlate with plaque inflammation and vulnerability. These findings imply that ¹⁸F-FDG PET might hold the promise for a new and better diagnostic test to identify patients eligible for carotid endarterectomy. The rationale for developing diagnostic tests based on molecular imaging with ¹⁸F-FDG PET, as well as methods for simple clinical PET approaches, are discussed. This is a systematic review, following Preferred Reporting Items for Systematic Reviews guidelines, which interrogated the PUBMED database from January 2001 to November 2019. The search combined the terms, “atherosclerosis,” “inflammation,” “FDG,” and “plaque imaging.” The search criteria included all types of studies, with a primary outcome of the degree of arterial vascular inflammation determined by ¹⁸F-FDG uptake. This review examines the role of ¹⁸F-FDG PET imaging in the characterization of atherosclerotic plaques.

Comparison of Long Term Prognosis between Carotid Endarterectomy versus Stenting; A Korean Population-Based Study Using National Insurance Data

Purpose

Although carotid endarterectomy (CEA) is recommended as a treatment for carotid stenosis rather than carotid artery stenting (CAS), CAS has been preferred in Korea. The aim of this study was to analyze long-term outcomes after CAS compared with CEA using Korean nationwide insurance data.Materials and

Methods

We obtained all data from the nationwide database of the Health Insurance Review & Assessment Service (HIRA) during the study period using several codes regarding the procedure or operation. We included the HIRA data, which included at least one-year follow-up after the procedures. The outcomes associated with both procedures were death, recurrence of ischemic stroke, and admission for cerebral hemorrhage.

Results

A total of 16,065 eligible patients who were treated with CAS or CEA between 1 January 2007 and 31 December 2016 were analyzed. The number of patients with CAS and CEA was 12,173 (75.8%) and 3,892 (24.2%), respectively. 8,976 patients (55.9%) were classified as symptomatic patients. CAS was associated with a higher risk of all-cause mortality (adjusted hazard ratio [HR], 1.282; 95% confidence interval [CI], 1.173–1.400). The adjusted rates for recurrent ischemic stroke and cerebral hemorrhage between CAS versus CEA were 24.9% versus 15.9% (HR, 1.474; 95% CI, 1.325–1.639) and 1.5% versus 0.9% (HR, 2.026; 95% CI, 1.322–3.106), respectively. In young symptomatic patients, there was no statistically significant difference in all-cause mortality and cardiovascular death between CAS and CEA.

Conclusion

Our study using Korean nationwide insurance data demonstrated similar results to previous studies. Until further evidence of CAS is established through prospective studies, CAS should be performed in selected patients according to current guidelines.

Geometric determinants of local hemodynamics in severe carotid artery stenosis

In cases of severe carotid artery stenosis (CAS), carotid endarterectomy (CEA) is performed to recover lumen patency and alleviate stroke risk. Under current guidelines, the decision to surgically intervene relies primarily on the percent loss of native arterial lumen diameter within the stenotic region (i.e. the degree of stenosis). An underlying premise is that the degree of stenosis modulates flow-induced wall shear stress elevations at the lesion site, and thus indicates plaque rupture potential and stroke risk. Here, we conduct a retrospective study on pre-CEA computed tomography angiography (CTA) images from 50 patients with severe internal CAS (>60% stenosis) to better understand the influence of plaque and local vessel geometry on local hemodynamics, with geometrical descriptors that extend beyond the degree of stenosis. We first processed CTA images to define a set of multipoint geometric metrics characterizing the stenosed region, and next performed computational fluid dynamics simulations to quantify local wall shear stress and associated hemodynamic metrics. Correlation and regression analyses were used to relate obtained geometric and hemodynamic metrics, with inclusion of patient sub-classification based on the degree of stenosis. Our results suggest that in the context of severe CAS, prediction of shear stress-based metrics can be enhanced by consideration of readily available, multipoint geometric metrics in addition to the degree of stenosis.

Association between physical activity and sedentary behaviour on carotid atherosclerotic plaques: an epidemiological and histological study in 90 asymptomatic patients

OBJECTIVE

Carotid atherosclerotic plaques are a source of emboli for stroke. 'Unstable' carotid atherosclerotic plaques may have intraplaque haemorrhages, neovessels, prevalent macrophages, excessive calcium deposits, a large lipid core and a thin fibrous cap. Regular physical activity (PA) may lower the risk of plaques becoming unstable. We evaluated the association of both PA and sedentary behaviour (SB) with carotid plaque histopathology.

METHODS

90 asymptomatic patients who were undergoing carotid endarterectomy for carotid artery narrowing identified on ultrasound reported their PA and SB by questionnaires. We calculated PA intensity in MET (metabolic equivalent of task)-min/week. For analysis, the population was divided into tertiles according to PA (T1PA: the less PA patients; T2PA: the intermediate PA patients; T3PA: the most physically active patients) (T1PA<T2PA<T3PA) and SB (T1SB: the less sedentary behaviour patients; T2SB: the intermediate sedentary behaviour patients; T3SB: the most sedentary behaviour patients) (T1SB<T2SB<T3SB). PA was categorised as one of four PA intensities (600, 900, 1600 and 3000 MET-min/week). We obtained the carotid artery plaque at surgery and performed histological analysis of intraplaque haemorrhages (present/absent), neovessels, macrophages, lipid core, calcium deposits and the fibrous cap.

RESULTS

Intraplaque haemorrhage was less frequent in the most physically active tertile (T3PA, 48%) versus T1PA (74%) and in the least sedentary tertile T1SB (50%) versus T3SB (71%). The intraplaque haemorrhage was less frequent in those who exercised more than 900 MET-min/week (59% vs 47% for >900 and <900 MET-min/week, respectively). All the other features that associate with plaque instability (eg, neovessels, macrophages, etc) did not differ by level of PA or SB.

CONCLUSION

In this cross-sectional study of asymptomatic patients who underwent endarterectomy (i) higher reported PA, (ii) intensity of PA and (iii) lower reported SB were associated with lower prevalence of intraplaque haemorrhage. This could be a mechanism whereby PA protects against cerebrovascular disease (stroke) and death.

Asymptomatic Carotid Stenosis: Intervention or Best Medical Therapy?

PURPOSE OF REVIEW

Provide a current overview regarding the optimal strategy for managing patients with asymptomatic carotid artery stenosis.

RECENT FINDINGS

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) reduce long-term stroke risk in asymptomatic patients. However, CAS is associated with a higher risk of peri-procedural stroke. Improvements in best medical therapy (BMT) have renewed uncertainty regarding the extent to which results from older randomised controlled trials (RCTs) comparing outcomes following carotid intervention can be generalised to modern medical practise. 'Average surgical risk' patients with an asymptomatic carotid artery stenosis of 60-99% and increased risk of late stroke should be considered for either CEA or CAS. In patients deemed 'high risk' for surgery, CAS is indicated. Use of an anti-platelet, anti-hypertensive and statin, with strict glycaemic control, is recommended. Results from ongoing large, multicentre RCTs comparing CEA, CAS and BMT will provide clarity regarding the optimal management of patients with asymptomatic carotid artery stenosis.

Noninvasive Assessment of Stenotic Severity and Plaque Characteristics by Coronary CT Angiography in Patients Scheduled for Carotid Artery Revascularization

Aims: Coronary artery atherosclerosis in patients needing carotid revascularization has not been fully clarified. The aim of this study was to evaluate the stenotic severity and plaque characteristics of coronary arteries by coronary computed tomography angiography (CTA) in patients scheduled for carotid-artery stenting (CAS) or carotid endarterectomy (CEA).

Methods: We performed coronary CTA after carotid ultrasound (US) in 164 patients (81.7% male, aged 68.1 ± 12.2 years) from 2014 to 2016. Of all, 70 were scheduled for CAS or CEA (CAS/CEA group) and 94 were not (non-CAS/CEA group). Carotid US and coronary CTA were compared for the evaluation of stenotic severity and plaque characteristics of each vessel between CAS/CEA and non-CAS/CEA groups.

Results: Between the two groups, there were significant differences in the presence of significant stenosis (SS: ≥ 70% stenosis of coronary artery) (55.7% vs. 39.4%, P = 0.038), triple-vessel disease (TVD)/left main trunk (LMT) (SS in each of three epicardial vessels and/or LMT) (24.3% vs. 7.5%, P = 0.0025), and high-risk plaque (HRP: positive remodeling and/or low attenuation) (55.7% vs. 24.5%, P < 0.0001). CAS/CEA was independently associated with TVD/LMT (OR = 2.30, 95%CI: 1.14–8.59, P = 0.026) and HRP (OR = 3.17, 95%CI: 1.57–6.54, P = 0.0012) in multivariable logistic regression analysis. Similarly, vulnerable plaque (78.6% vs. 2.1%, P < 0.0001) as well as severe stenosis of carotid artery (98.6% vs. 0%, P < 0.0001) was seen more often in CAS/CEA than in non-CAS/CEA group.

Conclusions: The prevalence of TVD/LMT and HRP determined by coronary CTA is higher in patients needing CAS/CEA than in those without. Management of systemic atherosclerosis is required in the perioperative period of CAS/CEA.

Pravastatin Reduces the Risk of Atherothrombotic Stroke when Administered within Six Months of an Initial Stroke Event

Aims: The J-STARS study examined whether pravastatin (10 mg/day) reduces recurrence of stroke in non-cardioembolic ischemic stroke patients who were enrolled within 1 month to 3 years after initial stroke events (ClinicalTrials.gov, NCT00221104). The main results showed that the frequency of atherothrombotic stroke was low in pravastatin-treated patients, although no effect of pravastatin was found for the other stroke subtypes. We evaluated differences of early (within 6 months) or late (after 6 months) pravastatin treatment benefits on the incidence of stroke or transient ischemic attack (TIA), as well as atherothrombotic stroke and the other subtypes.

Methods: Subjects in the J-STARS study were classified into two cohorts, depending on whether they enrolled early (1 to 6 months) or late (6 months to 3 years) following initial stroke events.

Results: A total of 1578 patients (491 female, 66.2 ± 8.5 years) were randomly assigned to either the pravastatin group (n = 793; n = 426 in the early cohort, n = 367 in the late cohort) or the control group (n = 785; n = 417 in the early cohort, n = 368 in the late cohort). During the follow-up of 4.9 ± 1.4 years, the rate of atherothrombotic stroke was lower in the pravastatin group compared to controls in the early cohort (0.24 vs. 0.88%/year, p = 0.01) but not in the late cohort (0.17 vs. 0.39%/year, p = 0.29). However, this difference of pravastatin effect on atherothrombotic stroke was not significantly interacted by the early or late cohort (p = 0.59). The incidence rates of other stroke subtype were not different in between pravastatin and control groups despite the timing of entry.

Conclusions: Pravastatin is likely to reduce atherothrombotic stroke in patients enrolled within 6 months after stroke onset. However, the clinical efficacy for prevention of recurrent stroke was not conclusive with earlier statin treatment.