Stent-Protected Angioplasty in Asymptomatic Carotid Artery Stenosis vs. Endarterectomy: SPACE2 – a Three-Arm Randomised-Controlled Clinical Trial

Impact of carotid stenosis on the outcome of stroke patients submitted to reperfusion treatments: a narrative review

Intravenous thrombolysis (IT) and mechanical thrombectomy (MD) are the two interventional approaches that have changed the outcome of patients with acute ischemic stroke (AIS). Ipsilateral and contralateral carotid stenosis (ICS, CCS) play an important role in regulating cerebral hemodynamics, both in chronic and acute situations such as AIS. Several studies have explored their role in the incidence and severity of stroke, but very few have investigated the possible impact of ICS and CCS on the efficacy of interventional procedures. The purpose of this review was to I) highlight the incidence and prevalence of carotid stenosis (CS); II) assess the impact of ICS and CCS on cerebral hemodynamics; III) evaluate the effect of carotid stenosis on the efficacy of interventional therapies (IT and MT) for AIS; and IV) report therapeutic complications related to CS. We searched PubMed/Medline for case reports, reviews, and original research articles on English-language review topics during the period from January 1, 2000 to October 1, 2023. CS is associated with 15-20 % of the total number of AIS. ICS and CCS had a negative influence on both cerebral hemodynamics before AIS and outcome after interventional procedures (IT, MT alone or in bridging). Available data on cerebral hemodynamics and efficacy of interventional therapies for AIS suggest a negative role of CS. Therefore, early diagnosis of CS may be considered relevant to preventive and post-stroke treatment strategies.

Proximal balloon-guided catheter with flow inversion vs. distal filter protection during the carotid stent placement, a seven years experience in a Colombian reference center

BACKGROUND AND PURPOSE

The carotid stent placement as a therapeutic option for carotid stenosis has been increasing among years; therefore, studies are required to evaluate the security and efficacy of its materials. The purpose of this study was to evaluate the distal filter and the proximal balloon-guided catheter with flow inversion as protection devices during carotid angioplasty and stenting.

METHODS

This is a retrospective, observational study of patients diagnosed with carotid stenosis treated with angioplasty between January 1, 2014, and June 30, 2020; we analyzed a radiology service database to compare the distal filter and the proximal balloon-guided catheter as protection devices during angioplasty.

RESULTS

One hundred seventy-five angioplasties were performed, the distal filter was the most prevalent embolic protection device used (66%), patients baseline characteristics did not differ between groups with different embolic protection devices, except for history of dyslipidemia (p < 0.000). As well, we did not find any significant differences between the groups in the device related complications, intervention time (p = 0.140), unrelated complications (p = 0.693) and functional independence at 90 days (p = 0.096).

CONCLUSIONS

In our study the proximal balloon-guided catheter and the distal filter protection device as protection devices during the carotid stenting didn't show significant differences regarding complications related to the system.

External Validity of Randomised Controlled Trials on Carotid Revascularisation: Trial Populations May Not Always Reflect Patients in Clinical Practice

OBJECTIVE

The external validity of randomised controlled trials (RCTs) and their transferability to clinical practice is under investigated. This study aimed to analyse the exclusion criteria of recent carotid RCTs comparing carotid endarterectomy (CEA) and carotid artery stenting, and to assess the eligibility of consecutive clinical practice cohorts to those RCTs.

METHODS

An analysis of the clinical and anatomical exclusion criteria of RCTs for asymptomatic (SPACE-2, ACST-2, CREST-1, and CREST-2) and symptomatic carotid stenosis (SPACE-1, CREST-1, ICSS, and EVA-3S) was performed. Two hundred consecutive asymptomatic and 200 consecutive symptomatic patients, treated by CEA, or transfemoral or transcarotid artery stenting at a tertiary referral university centre were assessed for their potential eligibility for each corresponding RCT. RCT patient data were pooled and differences from the clinical practice cohort analysed. Statistics were descriptive and comparative using Fisher's exact and t tests.

RESULTS

The number of clinical and anatomical exclusion criteria differed widely between RCTs. Potential eligibility rates of the clinical practice cohort for RCTs with regard to asymptomatic carotid stenosis were 80.5% (ACST-2), 79.5% (SPACE-2), 47% (CREST-1), and 20% (CREST-2). For RCTs on symptomatic carotid stenosis the eligibility rates were 89% (ICSS), 86.5% (EVA-3S), 64% (SPACE-1), and 39% (CREST-1). Both clinical practice cohorts were older by about three years and patients were more often male vs. the RCTs. Furthermore, a history of smoking (asymptomatic patients), hypertension (symptomatic patients), and atrial fibrillation was diagnosed more often, whereas hypercholesterolaemia and coronary heart disease (asymptomatic patients) were less prevalent. More clinical practice patients were on antiplatelets, anticoagulants, and lipid lowering drugs. Symptomatic clinical practice patients presented more often with retinal ischaemia and less often with minor hemispheric strokes than patients in the RCTs.

CONCLUSION

The external validity of contemporary carotid RCTs varies considerably. Patients in routine clinical practice differ from RCT populations with respect to age, comorbidities, and medication. These data are of interest for clinicians and guideline authors and may be relevant for the design of future comparative trials.

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).

Carotid Stenting Versus Endarterectomy for Asymptomatic Carotid Artery Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND

To compare safety and efficacy between carotid artery stenting (CAS) and carotid endarterectomy (CEA) in treating asymptomatic carotid artery stenosis based on results from randomized controlled trials.

METHODS

Randomized controlled trials comparing CAS and CEA in treating asymptomatic carotid artery stenosis were searched from databases of the EMBASE, PubMed, MEDLINE, and Cochrane libraries. Two independent reviewers identified eligible studies, extracted relevant data, and used the Cochrane risk of bias tool to assess quality. Mantel-Haenszel method random-effects models were used to estimate odds ratio (OR) regarding perioperative risks between CAS and CEA. Kaplan-Meier curve data were extracted and analyzed through Exp[(O-E)/Var] fixed-effect models to calculate the Peto odds ratio (OR) regarding long-term outcomes.

RESULTS

Sixteen articles from 7 randomized controlled trials were included, reporting relevant outcomes for 7230 asymptomatic carotid artery stenosis patients (CAS: n=3920; CEA: n=3198). Compared with the CEA group, CAS group had no difference in perioperative composite end point events including stroke, death, and myocardial infarction (MI; OR, 1.13 [95% CI, 0.87-1.47]; P=0.37, I²=0%). Compared with CEA, CAS had a higher risk of any stroke during the perioperative period (OR, 1.62 [95% CI, 1.16-2.24]; P=0.004, I²=0%) and an increased risk of nondisabling stroke (OR, 1.81 [95% CI, 1.23-2.65]; P=0.003, I²=0%), but there was no significant difference in disabling stroke and death between groups (OR, 0.91 [95% CI, 0.50-1.65]; P=0.76, I²=0%). For long-term outcomes, no difference regarding the composite outcome of any stroke, death, and myocardial infarction existed between CEA and CAS (Peto OR, 1.18 [95% CI, 0.94-1.48]; P=0.14, I²=0%). Individual-level patient data would be important to verify the long-term outcome results.

CONCLUSIONS

When treating asymptomatic carotid artery stenosis, CAS has comparable perioperative and long-term composite outcomes compared with CEA. However, CAS may have a higher risk of any stroke and nondisabling stroke in the perioperative period.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.

ANALYSIS OF SPIN IN VASCULAR SURGERY RANDOMIZED CONTROLLED TRIALS WITH NONSIGNIFICANT OUTCOMES

OBJECTIVES

Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS) for carotid stenosis (CS), and endovascular repair (EVAR) to open repair (OR) for abdominal aortic aneurysms (AAA).

METHODS

A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase three RCTs with nonsignificant primary outcomes comparing OR to EVAR or CEA to CAS were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs non-commercial) and (2) the publishing journal's impact factor.

RESULTS

Thirty-one of 355 articles captured were included for analysis. Spin was identified in nine abstracts (9/18) and 13 main texts (13/18) of AAA articles and seven abstracts (7/13) and ten main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the manuscript discussion section, with the most commonly employed strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (βOR = 0.96, 95% CI: 0.94 - 0.98, p < 0.01) while no significant association could be found with funding source (βOR = 1.33, 95% CI: 0.30-5.92, p = 0.71).

CONCLUSIONS

A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

Successful implementation of best medical treatment for patients with asymptomatic carotid artery stenosis within a randomized controlled trial (SPACE-2)

Background

Asymptomatic carotid artery stenosis (ACS) can be treated with carotid endarterectomy (CEA), carotid artery stenting (CAS), or best medical treatment (BMT) only. For all treatment options, optimization of vascular risk factors such as arterial hypertension, hyperlipidemia, smoking, obesity, and insufficient physical activity is essential. Data on adherence to BMT and lifestyle modification in patients with ACS are sparse. The subject of this investigation is the implementation and quality of risk factor adjustment in the context of a randomized controlled trial.

Methods

A total of 513 patients in the prematurely terminated, randomized, controlled, multicenter SPACE-2 trial (ISRCTN 78592017) were analyzed within one year after randomization into 3 groups (CEA, CAS, and BMT only) for implementation of prespecified BMT recommendations and lifestyle modifications. Measurement time points were the screening visit and visits after one month (D30), 6 months (M6), and one year (A1). Differences between groups and follow-up visits (FUVs) relative to the screening visit were investigated.

Findings

For all FUVs, a significant increase in statin medication (91% at A1; p < 0.0001) was demonstrated to be associated with a significant decrease (p < 0.01) in cholesterol levels (median 167 mg/dl at A1) and LDL cholesterol levels (median 93 mg/dl at A1). The lowest cholesterol levels were achieved by patients in the BMT group. Seventy-eight percent of all patients reached predefined target cholesterol levels (< 200 mg/dl), with significantly better rates in the BMT group (p = 0.036 at D30). Furthermore, a significant decrease in arterial blood pressure at all FUVs (p < 0.05) was associated with a significant increase in antihypertensive medication (96% at A1, p < 0.0001). However, only 28% of patients achieved the predefined treatment goal of a systolic blood pressure of ≤ 130 mmHg. Forty-two of a total of 100 smokers at the screening visit quit smoking within one year, resulting in a significant increase in nonsmokers at all FUVs (p < 0.0001). Recommended HbA1c levels (< 7%) were achieved in 82% without significant changes after one year. Only 7% of obese (BMI > 25) patients achieved sufficient weight reduction after one year without significant changes at all FUVs (median BMI 27 at A1; p = 0.1201). The BMT group showed significantly (p = 0.024) higher rates of adequate physical activity than the intervention groups. Furthermore, after one year, the BMT group showed a comparatively significantly better implementation of risk factor modification (77%; p = 0.027) according to the treating physician.

Interpretation

SPACE-2 demonstrated sustained improvement in the noninterventional management of vascular risk factors in patients treated in a clinical trial by general practitioners, internists and neurologists. The best implemented treatment targets were a reduction in cholesterol and HbA1c levels. In this context, a significant increase in statin use was demonstrated. Blood pressure control missed its target but was significantly reduced by intensification of antihypertensive medication. Patients on BMT only had better adjusted lipid parameters and were more physically active. However, all groups failed to achieve sufficient weight reduction. Due to insufficient patient recruitment, the results must be interpreted cautiously.

Trial registration: ISRCTN Registry, ISRCTN78592017, Registered 16 June 2007, https://www.isrctn.com/search?q=78592017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42466-021-00153-w.

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

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

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.

SOCIETY FOR VASCULAR SURGERY CLINICAL PRACTICE GUIDELINES FOR MANAGEMENT OF EXTRACRANIAL CEREBROVASCULAR DISEASE

Management of carotid bifurcation stenosis in stroke prevention has been the subject of extensive investigations, including multiple randomized controlled trials. The proper treatment of patients with carotid bifurcation disease is of major interest to vascular surgeons and other vascular specialists. In 2011, the Society for Vascular Surgery published guidelines for treatment of carotid artery disease. At the time, several randomized trials, comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS), were published. Since that publication, several studies and a few systematic reviews comparing CEA and CAS have been published, and the role of medical management has been re-emphasized. The current publication updates and expands the 2011 guidelines with specific emphasis on five areas: is carotid endarterectomy recommended over maximal medical therapy in low risk patients; is carotid endarterectomy recommended over trans-femoral carotid artery stenting in low surgical risk patients with symptomatic carotid artery stenosis of >50%; timing of carotid Intervention in patients presenting with acute stroke; screening for carotid artery stenosis in asymptomatic patients; and optimal sequence for intervention in patients with combined carotid and coronary artery disease. A separate implementation document will address other important clinical issues in extracranial cerebrovascular disease. Recommendations are made using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) approach, as has been done with other Society for Vascular Surgery guidelines. The committee recommends CEA as the first-line treatment for symptomatic low risk surgical patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 70% to 99%. The perioperative risk of stroke and death in asymptomatic patients must be <3% to ensure benefit for the patient. In patients with recent stable stroke (modified Rankin 0-2), carotid revascularization is considered appropriate in symptomatic patients with greater than 50% stenosis and is recommended and performed as soon as the patient is neurologically stable after 48 hours but definitely before 14 days of onset of symptoms. In the general population, screening for clinically asymptomatic carotid artery stenosis in patients without cerebrovascular symptoms or significant risk factors for carotid artery disease is not recommended. In selected asymptomatic patients who are at increased risk for carotid stenosis, we suggest screening for clinically asymptomatic carotid artery stenosis as long as the patients would potentially be fit for and willing to consider carotid intervention if significant stenosis is discovered. In patients with symptomatic carotid stenosis 50-99%, who require both CEA and CABG, we suggest CEA before or concomitant with CABG to potentially reduce the risk of stroke and stroke/death. The sequencing of the intervention depends on clinical presentation and institutional experience.

Trimethylamine-N-Oxide Levels Are Similar in Asymptomatic vs. Symptomatic Cerebrovascular Atherosclerosis

Introduction: Trimethylamine-N-oxide (TMAO) is correlated with atherosclerosis and vascular diseases such as coronary heart disease and ischemic stroke. The aim of the study was to investigate whether TMAO levels are different in symptomatic vs. asymptomatic cerebrovascular atherosclerosis. Methods: This was a prospective, case-control study, conducted at a tertiary care university hospital. Patients were included if they had large-artery atherosclerosis (TOAST criteria). Symptomatic patients with ischemic stroke were compared with asymptomatic patients. As primary endpoint, TMAO levels on admission were compared between symptomatic and asymptomatic patients. Univariable analysis was performed using Mann-Whitney U test and multivariable analysis using binary logistic regression. TMAO values were adjusted for glomerular filtration rate (GFR), age, and smoking. Results: Between 2018 and 2020, 82 symptomatic and asymptomatic patients were recruited. Median age was 70 years; 65% were male. Comparing symptomatic (n = 42) and asymptomatic (n = 40) patients, no significant differences were found in univariable analysis in TMAO [3.96 (IQR 2.30-6.73) vs. 5.36 (3.59-8.68) μmol/L; p = 0.055], GFR [87 (72-97) vs. 82 (71-90) ml/min^*1.73 m²; p = 0.189] and age [71 (60-79) vs. 69 (67-75) years; p = 0.756]. In multivariable analysis, TMAO was not a predictor of symptomatic cerebrovascular disease after adjusting for age and GFR [OR 1.003 (95% CI: 0.941-1.070); p = 0.920]. In a sensitivity analysis, we only analyzed patients with symptomatic stenosis and excluded patients with occlusion of brain-supplying arteries. Again, TMAO was not a significant predictor of symptomatic stenosis [OR 1.039 (0.965-1.120), p = 0.311]. Conclusion: TMAO levels could not be used to differentiate between symptomatic and asymptomatic cerebrovascular disease in our study.

Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis

BACKGROUND

Carotid artery stenting is an alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004, 2007, and 2012.

OBJECTIVES

To assess the benefits and risks of stenting compared with endarterectomy in people with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2018) and the following databases: CENTRAL, MEDLINE, Embase, and Science Citation Index to August 2018. We also searched ongoing trials registers (August 2018) and reference lists, and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing stenting with endarterectomy for symptomatic or asymptomatic atherosclerotic carotid stenosis. In addition, we included RCTs comparing carotid artery stenting with medical therapy alone.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and risk of bias, and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endarterectomy as the reference group. We quantified heterogeneity using the I² statistic and used GRADE to assess the overall certainty of evidence.

MAIN RESULTS

We included 22 trials involving 9753 participants. In participants with symptomatic carotid stenosis, compared with endarterectomy stenting was associated with a higher risk of periprocedural death or stroke (the primary safety outcome; OR 1.70, 95% CI 1.31 to 2.19; P < 0.0001, I² = 5%; 10 trials, 5396 participants; high-certainty evidence); and periprocedural death, stroke, or myocardial infarction (OR 1.43, 95% CI 1.14 to 1.80; P = 0.002, I² = 0%; 6 trials, 4861 participants; high-certainty evidence). The OR for the primary safety outcome was 1.11 (95% CI 0.74 to 1.64) in participants under 70 years old and 2.23 (95% CI 1.61 to 3.08) in participants 70 years old or more (interaction P = 0.007). There was a non-significant increase in periprocedural death or major or disabling stroke with stenting (OR 1.36, 95% CI 0.97 to 1.91; P = 0.08, I² = 0%; 7 trials, 4983 participants; high-certainty evidence). Compared with endarterectomy, stenting was associated with lower risks of myocardial infarction (OR 0.47, 95% CI 0.24 to 0.94; P = 0.03, I² = 0%), cranial nerve palsy (OR 0.09, 95% CI 0.06 to 0.16; P < 0.00001, I² = 0%), and access site haematoma (OR 0.32, 95% CI 0.15 to 0.68; P = 0.003, I² = 27%). The combination of periprocedural death or stroke or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.51, 95% CI 1.24 to 1.85; P < 0.0001, I² = 0%; 8 trials, 5080 participants; high-certainty evidence). The rate of ipsilateral stroke after the periprocedural period did not differ between treatments (OR 1.05, 95% CI 0.75 to 1.47; P = 0.77, I² = 0%). In participants with asymptomatic carotid stenosis, there was a non-significant increase in periprocedural death or stroke with stenting compared with endarterectomy (OR 1.72, 95% CI 1.00 to 2.97; P = 0.05, I² = 0%; 7 trials, 3378 participants; moderate-certainty evidence). The risk of periprocedural death or stroke or ipsilateral stroke during follow-up did not differ significantly between treatments (OR 1.27, 95% CI 0.87 to 1.84; P = 0.22, I² = 0%; 6 trials, 3315 participants; moderate-certainty evidence). Moderate or higher carotid artery restenosis (50% or greater) or occlusion during follow-up was more common after stenting (OR 2.00, 95% CI 1.12 to 3.60; P = 0.02, I² = 44%), but the difference in risk of severe restenosis was not significant (70% or greater; OR 1.26, 95% CI 0.79 to 2.00; P = 0.33, I² = 58%; low-certainty evidence).

AUTHORS' CONCLUSIONS

Stenting for symptomatic carotid stenosis is associated with a higher risk of periprocedural stroke or death than endarterectomy. This extra risk is mostly attributed to an increase in minor, non-disabling strokes occurring in people older than 70 years. Beyond the periprocedural period, carotid stenting is as effective in preventing recurrent stroke as endarterectomy. However, combining procedural safety and long-term efficacy in preventing recurrent stroke still favours endarterectomy. In people with asymptomatic carotid stenosis, there may be a small increase in the risk of periprocedural stroke or death with stenting compared with endarterectomy. However, CIs of treatment effects were wide and further data from randomised trials in people with asymptomatic stenosis are needed.

Update in the treatment of extracranial atherosclerotic disease for stroke prevention

Stroke is a leading cause of adult mortality and disability worldwide. Extracranial atherosclerotic disease (ECAD), primarily, carotid artery stenosis, accounts for approximately 18%–25% of ischaemic stroke. Recent advances in neuroimaging, medical therapy and interventional management have led to A significant reduction of stroke from carotid artery stenosis. The current treatment of ECAD includes optimal medical therapy, carotid endarterectomy (CEA) and carotid artery stenting (CAS). The selection of treatments depends on symptomatic status, severity of stenosis, individual factors, efficacy and risk of complications. The aim of this paper is to review current evidence and guidelines on the management of carotid artery stenosis, including the comparison of medical and interventional therapy (CAS and CEA), as well as future directions.

Angioplasty in asymptomatic carotid artery stenosis vs. endarterectomy compared to best medical treatment: One-year interim results of SPACE-2

BACKGROUND

Treatment of individuals with asymptomatic carotid artery stenosis is still handled controversially. Recommendations for treatment of asymptomatic carotid stenosis with carotid endarterectomy (CEA) are based on trials having recruited patients more than 15 years ago. Registry data indicate that advances in best medical treatment (BMT) may lead to a markedly decreasing risk of stroke in asymptomatic carotid stenosis. The aim of the SPACE-2 trial (ISRCTN78592017) was to compare the stroke preventive effects of BMT alone with that of BMT in combination with CEA or carotid artery stenting (CAS), respectively, in patients with asymptomatic carotid artery stenosis of ≥70% European Carotid Surgery Trial (ECST) criteria.

METHODS

SPACE-2 is a randomized, controlled, multicenter, open study. A major secondary endpoint was the cumulative rate of any stroke (ischemic or hemorrhagic) or death from any cause within 30 days plus an ipsilateral ischemic stroke within one year of follow-up. Safety was assessed as the rate of any stroke and death from any cause within 30 days after CEA or CAS. Protocol changes had to be implemented. The results on the one-year period after treatment are reported.

FINDINGS

It was planned to enroll 3550 patients. Due to low recruitment, the enrollment of patients was stopped prematurely after randomization of 513 patients in 36 centers to CEA (n = 203), CAS (n = 197), or BMT (n = 113). The one-year rate of the major secondary endpoint did not significantly differ between groups (CEA 2.5%, CAS 3.0%, BMT 0.9%; p = 0.530) as well as rates of any stroke (CEA 3.9%, CAS 4.1%, BMT 0.9%; p = 0.256) and all-cause mortality (CEA 2.5%, CAS 1.0%, BMT 3.5%; p = 0.304). About half of all strokes occurred in the peri-interventional period. Higher albeit statistically non-significant rates of restenosis occurred in the stenting group (CEA 2.0% vs. CAS 5.6%; p = 0.068) without evidence of increased stroke rates.

INTERPRETATION

The low sample size of this prematurely stopped trial of 513 patients implies that its power is not sufficient to show that CEA or CAS is superior to a modern medical therapy (BMT) in the primary prevention of ischemic stroke in patients with an asymptomatic carotid stenosis up to one year after treatment. Also, no evidence for differences in safety between CAS and CEA during the first year after treatment could be derived. Follow-up will be performed up to five years. Data may be used for pooled analysis with ongoing trials.

Carotid Endarterectomy and Carotid Artery Stenting in the US Medicare Population, 1999-2014

IMPORTANCE

Carotid endarterectomy and carotid artery stenting are the leading approaches to revascularization for carotid stenosis, yet contemporary data on trends in rates and outcomes are limited.

OBJECTIVE

To describe US national trends in performance and outcomes of carotid endarterectomy and stenting among Medicare beneficiaries from 1999 to 2014.

DESIGN, SETTING, AND PARTICIPANTS

Serial cross-sectional analysis of Medicare fee-for-service beneficiaries aged 65 years or older from 1999 to 2014 using the Medicare Inpatient and Denominator files. Spatial mixed models adjusted for age, sex, and race were fit to calculate county-specific risk-standardized revascularization rates. Mixed models were fit to assess trends in outcomes after adjustment for demographics, comorbidities, and symptomatic status.

EXPOSURES

Carotid endarterectomy and carotid artery stenting.

MAIN OUTCOMES AND MEASURES

Revascularization rates per 100 000 beneficiary-years of fee-for-service enrollment, in-hospital mortality, 30-day stroke or death, 30-day stroke, myocardial infarction, or death, 30-day all-cause mortality, and 1-year stroke.

RESULTS

During the study, 937 111 unique patients underwent carotid endarterectomy (mean age, 75.8 years; 43% women) and 231 077 underwent carotid artery stenting (mean age, 75.4 years; 49% women). There were 81 306 patients who underwent endarterectomy in 1999 and 36 325 in 2014; national rates per 100 000 beneficiary-years decreased from 298 in 1999-2000 to 128 in 2013-2014 (P < .001). The number of patients who underwent stenting ranged from 10 416 in 1999 to 22 865 in 2006 (an increase per 100 000 beneficiary-years from 40 in 1999-2000 to 75 in 2005-2006; P < .001); by 2014, there were 10 208 patients who underwent stenting and the rate decreased to 38 per 100 000 beneficiary-years (P < .001). Outcomes improved over time despite increases in vascular risk factors (eg, hypertension prevalence increased from 67% to 81% among patients who underwent endarterectomy and from 61% to 70% among patients who underwent stenting) and the proportion of symptomatic patients (all P < .001). There were adjusted annual decreases in 30-day ischemic stroke or death of 2.90% (95% CI, 2.63% to 3.18%) among patients who underwent endarterectomy and 1.13% (95% CI, 0.71% to 1.54%) among patients who underwent stenting; an absolute decrease from 1999 to 2014 was observed for endarterectomy (1.4%; 95% CI, 1.2% to 1.5%) but not stenting (-0.1%; 95% CI, -0.5% to 0.4%). Rates for 1-year ischemic stroke decreased after endarterectomy (absolute decrease, 3.5% [95% CI, 3.2% to 3.7%]; adjusted annual decrease, 2.17% [95% CI, 2.00% to 2.34%]) and stenting (absolute decrease, 1.6% [95% CI, 1.2% to 2.1%]; adjusted annual decrease, 1.86% [95% CI, 1.45%-2.26%]). Additional improvements were noted for in-hospital mortality, 30-day stroke, myocardial infarction, or death, and 30-day all-cause mortality as well as within demographic subgroups.

CONCLUSIONS AND RELEVANCE

Among fee-for-service Medicare beneficiaries, the performance of carotid endarterectomy declined from 1999 to 2014, whereas the performance of carotid artery stenting increased until 2006 and then declined from 2007 to 2014. Outcomes improved despite increases in vascular risk factors.

Endarterectomy achieves lower stroke and death rates compared with stenting in patients with asymptomatic carotid stenosis

BACKGROUND

It is currently unclear if carotid artery stenting (CAS) is as safe as carotid endarterectomy (CEA) for patients with significant asymptomatic stenosis. The aim of our study was to perform a systematic review and meta-analysis of trials comparing CAS with CEA.

METHODS

On March 17, 2017, a search for randomized controlled trials was performed in MEDLINE and Scopus databases with no time limits. We performed meta-analyses with Peto odds ratios (ORs) and 95% confidence intervals (CIs). Quality of evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation method. The primary safety and efficacy outcome measures were stroke or death rate at 30 days and ipsilateral stroke at 1 year (including ipsilateral stroke and death rate at 30 days), respectively. Perioperative stroke, ipsilateral stroke, myocardial infarction (MI), and cranial nerve injury (CNI) were all secondary outcome measures.

RESULTS

The systematic review of the literature identified nine randomized controlled trials reporting on 3709 patients allocated into CEA (n = 1479) or CAS (n = 2230). Stroke or death rate at 30 days was significantly higher for CAS (64/2176 [2.94%]) compared with CEA (27/1431 [1.89%]; OR, 1.57; 95% CI, 1.01-2.44; P = .044), with low level of heterogeneity beyond chance (I² = 0%). Also, stroke rate at 30 days was significantly higher for CAS (63/2176 [2.90%]) than for CEA (26/1431 [1.82%]; OR, 1.63; 95% CI, 1.04-2.54; P = .032; I² = 0%). MI at 30 days was nonsignificantly lower for CAS (12/1815 [0.66%]) compared with CEA (16/1070 [1.50%]; OR, 0.53; 95% CI, 0.24-1.14; P = .105; I² = 0%); however, CNI at 30 days was significantly lower for CAS (2/1794 [0.11%]) than for CEA (33/1061 [3.21%]; OR, 0.13; 95% CI, 0.07-0.26; P < .00001; I² = 0%). Regarding the long-term outcome of stroke or death rate at 30 days plus ipsilateral stroke during follow-up, this was significantly higher for CAS (79/2173 [3.64%]) than for CEA (35/1430 [2.45%]; OR, 1.51; 95% CI, 1.02-2.24; P = .04; I² = 0%). Quality of evidence for all stroke outcomes was graded moderate.

CONCLUSIONS

Among patients with asymptomatic stenosis undergoing carotid intervention, there is moderate-quality evidence to suggest that CEA had significantly lower 30-day stroke and also stroke or death rates compared with CAS at the cost of higher CNI and nonsignificantly higher MI rates. The long-term efficacy of CEA in ipsilateral stroke prevention, taking into account perioperative stroke and death, was preserved during follow-up. There is an urgent need for high-quality research before a firm recommendation is made that CAS is inferior or not to CEA.

Real-world experience of treatment decision-making in carotid stenosis in a neurovascular board

OBJECTIVE

To describe our experience with consensus-based decision-making for treatment of internal carotid artery (ICA) stenosis by neurologists, interventional neuroradiologists, vascular surgeons, and neurosurgeons in a multidisciplinary neurovascular board and to study adherence to treatment recommendations in the context of uncertainty with respect to the best treatment option.

METHODS

We established a multidisciplinary neurovascular board meeting twice a week with structured documentation of consensus decisions. Over a time period of 53 months, 614 cases with ICA stenosis were discussed, with 285 (46%) symptomatic and 279 (45%) asymptomatic cases.

RESULTS

Recommendation for symptomatic ICA stenosis was revascularization in 76%, medical management alone in 8%, and further diagnostics in 16%. For asymptomatic ICA stenosis, recommendation was randomization in a clinical trial in 29%, revascularization in 27%, medical management alone in 23%, and further diagnostics in 22%. Treatment recommendations were followed in 94% of symptomatic ICA stenosis and 69% of asymptomatic ICA stenosis. Patients in whom carotid artery stenting was recommended for revascularization were younger and showed a higher rate of severe (≥70%) ICA stenosis.

CONCLUSIONS

Interdisciplinary board decisions are a helpful and transparent tool to assure adherence to guideline recommendations, and to provide consensus-based individualized treatment strategies in clinical practice in the absence of unequivocal evidence.

SPACE-2: A Missed Opportunity to Compare Carotid Endarterectomy, Carotid Stenting, and Best Medical Treatment in Patients with Asymptomatic Carotid Stenoses

BACKGROUND

Because of recent advances in best medical treatment (BMT), it is currently unclear whether any additional surgical or endovascular interventions confer additional benefit, in terms of preventing late ipsilateral carotid territory ischemic stroke in asymptomatic patients with significant carotid stenoses. The aim was to compare the stroke-preventive effects of BMT alone, with that of BMT in combination with carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with high grade asymptomatic extracranial carotid artery stenosis.

METHODS

SPACE-2 was planned as a three-armed, randomized controlled trial (BMT alone vs. CEA plus BMT vs. CAS plus BMT, ISRCTN 78592017). However, because of slow patient recruitment, the three-arm study design was amended (July 2013) to become two parallel randomized studies (BMT alone vs. CEA plus BMT, and BMT alone vs. CAS plus BMT).

RESULTS

The change in study design did not lead to any significant increase in patient recruitment, and trial recruitment ceased after recruiting 513 patients over a 5 year period (CEA vs. BMT (n = 203); CAS vs. BMT (n = 197), and BMT alone (n = 113)). The 30 day rate of death/stroke was 1.97% for patients undergoing CEA, and 2.54% for patients undergoing CAS. No strokes or deaths occurred in the first 30 days after randomization in patients randomized to BMT. There were several potential reasons for the low recruitment rates into SPACE-2, including the ability for referring doctors to refer their patients directly for CEA or CAS outwith the trial, an inability to convince patients (who had come "mentally prepared" that an intervention was necessary) to accept BMT, and other economic constraints.

CONCLUSIONS

Because of slow recruitment rates, SPACE-2 had to be stopped after randomizing only 513 patients. The German Research Foundation will provide continued funding to enable follow up of all recruited patients, and it is also planned to include these data in any future meta-analysis prepared by the Carotid Stenosis Trialists Collaboration.

Critical Issues That Need to Be Addressed to Improve Outcomes for Patients With Carotid Stenosis

Significant improvement in outcomes for patients with carotid stenosis requires liberation from the historic fixation with randomization and a procedurally based, late-stage, reactive approach to medical care. We require a multipronged and multidisciplinary approach that includes all of the following: (i) removal of overreliance on, and biased use of, randomized trial data; (ii) using accurate ways to rank evidence quality and relevance; (iii) improved research reporting standards; (iv) building quality assurance and other research capability into routine practice; (v) producing evidence-true rather than evidence-based guidelines; (vi) bringing current optimal medical treatment to the community and measuring its effectiveness; (vii) funding only interventions known to help patients when and where they are treated and use the savings to fund vital research, including quality assurance in routine practice; and (viii) recognize that making the indication for carotid procedures obsolete is a good thing.

Modern medical treatment with or without carotid endarterectomy for severe asymptomatic carotid atherosclerosis

OBJECTIVE

This study assessed the value of modern medical treatment (MMT) with and without carotid endarterectomy (CEA) in patients with asymptomatic severe carotid artery stenosis.

METHODS

We conducted a randomized trial involving 55 patients with 70% to 79% carotid stenosis at three Russian centers. Between 2009 and 2013, 31 patients were randomized to undergo CEA with MMT (CEA group) and 24 to receive MMT alone. The primary end point was nonfatal ipsilateral stroke or death from any cause during a follow-up period of 5.0 years. The secondary end point was any nonfatal stroke, carotid revascularization, or death from any cause during follow-up.

RESULTS

The trial was stopped after a median follow-up of 3.3 years (maximum, 5.0 years). There were two primary events in the CEA group and nine events in the MMT group. The 3.3-year cumulative primary event rates were 6.5% in the CEA group and 37.5% in the MMT group (hazard ratio for the MMT group, 5.06; 95% confidence interval, 1.53-16.79; P = .008). The 3.3-year cumulative secondary end point was 12.9% in the CEA group and 50.0% in the MMT group (hazard ratio for the MMT group, 4.23; 95% confidence interval, 1.55-11.53; P = .0048).

CONCLUSIONS

CEA as an initial management strategy could reduce the risk of death and major cerebrovascular events when added to MMT.

Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.

Temporal trends in safety of carotid endarterectomy in asymptomatic patients: systematic review

OBJECTIVE

To systematically review temporal changes in perioperative safety of carotid endarterectomy (CEA) in asymptomatic individuals in trial and registry studies.

METHODS

The MEDLINE and EMBASE databases were searched using the terms "carotid" and "endarterectomy" and "asymptomatic" from 1947 to August 23, 2014. Articles dealing with 50%-99% stenosis in asymptomatic individuals were included and low-volume studies were excluded. The primary endpoint was 30-day stroke or death and the secondary endpoint was 30-day all-cause mortality. Statistical analysis was performed using random-effects meta-regression for registry data and for trial data graphical interpretation alone was used.

RESULTS

Six trials (n = 4,431 procedures) and 47 community registries (n = 204,622 procedures) reported data between 1983 and 2013. Registry data showed a significant decrease in postoperative stroke or death incidence over the period 1991-2010, equivalent to a 6% average proportional annual reduction (95% credible interval [CrI] 4%-7%; p < 0.001). Considering postoperative all-cause mortality, registry data showed a significant 5% average proportional annual reduction (95% CrI 3%-9%; p < 0.001). Trial data showed a similar visual trend.

CONCLUSIONS

CEA is safer than ever before and high-volume registry results closely mirror the results of trials. New benchmarks for CEA are a stroke or death risk of 1.2% and a mortality risk of 0.4%. This information will prove useful for quality improvement programs, for health care funders, and for those re-examining the long-term benefits of asymptomatic revascularization in future trials.

Optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis

This commentary addresses the issue of optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis. Based on current data, carotid endarterectomy (CEA) should be performed in the majority of patients with symptomatic carotid artery stenosis. Carotid artery stenting (CAS) should be reserved for a minority of these symptomatic patients, in whom CEA is contraindicated. In asymptomatic patients, all should be placed on best medical treatment (BMT). With the use of one or more of the proposed stroke risk stratification models or some as yet undetermined method, the identification of those asymptomatic individuals may be possible in whom stroke risk is higher than usual with BMT. This asymptomatic subgroup, which may be small and is yet to be determined with certainty, could be offered an invasive carotid procedure (either CAS or CEA).

Evidence for management of carotid artery stenosis

In this review, we presented the evidence concerning carotid artery stenosis treatment in symptomatic stenosis and asymptomatic stenosis separately, and discussed the future challenges. The validity of carotid endarterectomy (CEA) to treat moderate or greater degree of symptomatic carotid artery stenosis appears to be established. Due to the additional option of carotid artery stenting (CAS), it is necessary to comprehensively determine whether CEA or CAS is more appropriate for each individual patient. Moreover, since there are rapid advancements in devices for CAS and improvements in treatment outcomes, continual learning of the latest treatment method is essential. For asymptomatic stenosis, due to improvements in the outcomes with best medical treatment (BMT), it is essential to re-evaluate the use of invasive CEA/CAS. Continual verification of the latest randomized clinical trial that compares CEA, CAS, and BMT, and establishment of a diagnostic method that can accurately extract the group of patients who have the highest future risk of developing ischemia, are desired.

Endarterectomy or carotid artery stenting: the quest continues part two

BACKGROUND

Although randomized trials on carotid artery stenting (CAS) could not establish its equivalence to carotid endarterectomy (CEA) in patients with symptomatic carotid disease, CAS is rapidly evolving. Data on long-term outcome after CAS from randomized trials have now become available and ongoing, prospectively held registries frequently publish their results in increasing numbers of patients. We have therefore reviewed the currently available literature and provide an update of our previous article on this topic.

DATA SOURCES

PubMed literature searches were performed to identify relevant studies regarding current status of CEA and stenting for symptomatic carotid stenosis.

CONCLUSIONS

The efficacy of CAS in patients with symptomatic carotid artery stenosis remains unclear because of varying results in randomized trials. Although multiple registries do report promising results after CAS, peri-interventional stroke/death rates still exceed those rates currently found after CEA. Therefore, CEA remains the "gold standard" in treating these patients.

Asymptomatic carotid stenosis: What we can learn from the next generation of randomized clinical trials

Stroke remains an exceedingly incident and prevalent public health burden across the globe, with an estimated 16 million new strokes per annum and prevalence over 60 million, and extracranial internal carotid artery atherosclerotic disease is an important risk factor for stroke. Randomized trials of surgical treatment were conducted (North American Symptomatic Carotid Endarterectomy Trial, European Carotid Surgery Trial) and demonstrated efficacy of carotid endarterectomy for secondary prevention of stroke in patients with cerebrovascular events (e.g. ipsilateral stroke, transient ischemic attack, and/or amaurosis fugax) attributable to a diseased artery with 50–99% stenosis. Therapeutic clarity, however, proved elusive with asymptomatic carotid artery disease. Asymptomatic Carotid Atherosclerosis Study (ACAS), Asymptomatic Carotid Surgery Trial, and Veterans Affairs Cooperative Study (VACS) suggested only modest benefit from surgical intervention for primary stroke prevention and the best medical therapy at the time of these trials is not comparable to modern medical therapy. ACT-1, Asymptomatic Carotid Surgery Trial-2, Stent-Protected Angioplasty in asymptomatic Carotid artery stenosis versus Endarterectomy Trial-2, European Carotid Surgery Trial-2, Carotid Revascularization Endarterectomy Versus Stenting Trial-2 are trials that are recent, ongoing, or in development that include diverse populations across Europe and North America, complementary trial designs, and a collaborative spirit that should provide clinicians with evidence that informs best clinical practice for asymptomatic carotid artery disease.

Asymptomatic carotid artery stenosis: time to rethink our therapeutic options?

Asymptomatic carotid artery stenosis is a well-recognized risk factor for ischemic stroke, and its prevalence increases with age. In the late 1980s and in the 1990s, well-designed randomized trials established a definite advantage for carotid endarterectomy in reducing the risk of ipsilateral stroke when compared with medical therapy alone. However, medical treatment of cardiovascular disease has improved significantly over the past 2 decades, and this has, in turn, resulted in a decline of the stroke risk in patients with asymptomatic carotid artery stenosis treated medically. This improvement in medical therapy casts doubts on the effectiveness of large-scale invasive treatment in patients with asymptomatic carotid artery stenosis. Several studies have been conducted to identify possible subgroups of patients with asymptomatic stenosis who are at higher risk of stroke in order to maximize the potential benefits of invasive treatment. Ongoing large-scale trials comparing best current medical therapy to available invasive treatments, such as carotid endarterectomy and carotid artery stenting, are likely to shed some light on this debated topic in the near future. In this review, the authors summarize the current controversy surrounding the ideal management of asymptomatic carotid artery stenosis.

[Treatment of asymptomatic carotid artery stenosis: improvement of evidence with new SPACE-2 design necessary]

Asymptomatic carotid artery stenosis may be treated with carotid endarterectomy (CEA), carotid artery stenting (CAS) or with best medical treatment (BMT) only. Definitive and evidence-based treatment recommendations for one of these options are currently not possible. Studies showing an advantage of CEA over BMT alone do not meet current standards from a pharmacological point of view. On the other hand, more recent data point to a further stroke risk reduction using BMT according to current standards. Studies on carotid artery stenting as a third alternative treatment are partially insufficient, especially when comparing CAS with BMT. Initiated in 2009, the randomized, controlled, multicenter SPACE-2 trial is intended to answer the question about the best treatment option of asymptomatic carotid artery stenosis; however, to increase recruitment rates as a condition for the successful completion of this important study, the trial design had to be modified.

Advances and challenges in treatment and prevention of ischemic stroke

We review recent advances in the treatment and prevention of acute ischemic stroke, including the current state of endovascular therapy, in light of 5 randomized controlled trials published this past year. Although no benefit of endovascular therapy over intravenous (IV) recombinant tissue plasminogen activator (rt-PA) has been demonstrated, endovascular therapy is an appropriate treatment for acute ischemic stroke patients within the t-PA window who are ineligible for IV t-PA but have a large vascular occlusion. These trials reveal promises and current limitations of endovascular therapy, and comparison of reperfusion therapies remains an important area of research. One common theme is the strong association between a faster time to reperfusion, improved outcome, and reduced mortality. Primary and secondary stroke prevention trials emphasize the importance of aggressive management of medical risk factors as part of any preventative strategy. New oral anticoagulants, for example, offer cost-effective risk reduction in patients with atrial fibrillation, and may represent an opportunity for those with cryptogenic stroke. We highlight areas of unmet need and promising research in stroke, including the need to deliver proven therapies to more patients, and the need to recruit patients into clinical trials that better define the role of endovascular and other stroke therapies. Finally, improvement in strategies to recover speech, cognition, and motor function has the potential to benefit far more stroke patients than any acute stroke therapy, and represents the greatest opportunity for research in the coming century.

[Carotid artery stenting--an update]

CLINICAL/METHODICAL ISSUE

Therapy of carotid stenosis should be based on an accurate assessment of the stenosis and a differentiation between symptomatic and asymptomatic patients.

STANDARD RADIOLOGICAL METHODS

According to current guidelines carotid artery stenting (CAS) can be considered as an established therapeutic alternative to carotid endarterectomy (CEA).

METHODICAL INNOVATIONS

For the therapy of carotid stenosis CAS has become established as a minimally invasive alternative to CEA because the complication rate has been reduced due to growing experience, technical innovations and external quality assessment.

PERFORMANCE

The CAS procedure should be performed in centers with documented complication rates of < 3 % for asymptomatic and < 6 % for symptomatic stenoses.

ACHIEVEMENTS

Overall there are no significant differences between CAS and CEA in the treatment of carotid stenosis concerning the secondary prophylactic effect.

PRACTICAL RECOMMENDATIONS

Ideally an interdisciplinary approach should be chosen for the therapy regime. Revascularization of asymptomatic stenoses should be considered critically as these patients might profit from optimized conservative medicinal therapy.

The diagnosis, treatment and follow-up of extracranial carotid stenosis

BACKGROUND

Extracranial atherosclerotic lesions of the carotid bifurcation cause 10% to 20% of all cases of cerebral ischemia. Until now, there have been no comprehensive evidence- and consensus-based recommendations for the management of patients with extracranial carotid stenosis in Germany and Austria.

METHODS

The literature was systematically searched for pertinent publications (1990-2011). On the basis of 182 randomized clinical trials (RCTs) and 308 systematic reviews, 30 key questions were answered and evidence-based recommendations were issued.

RESULTS

The prevalence of extracranial carotid stenosis is more than 5% from age 65 onward. Men are affected twice as frequently as women. The most important diagnostic technique is Doppler- and color-coded duplex ultrasonography. RCTs have shown that the treatment of high-grade asymptomatic carotid stenosis with carotid endarterectomy (CEA) can lower the 5-year risk of stroke from 11% to 5%. Intensive conservative treatment may lower the stroke risk still further. Moreover, RCTs have shown that CEA for symptomatic 50% to 99% carotid stenosis lowers the 5-year stroke risk by 5% to 16%. Meta-analyses of the 13 available RCTs comparing carotid artery stenting (CAS) with CEA have shown that CAS is associated with a 2% to 2.5% higher risk of periprocedural stroke or death and with a 0.5% to 1% lower risk of periprocedural myocardial infarction. If no particular surgical risk factors are present, CEA is the standard treatment for high-grade carotid stenosis. CAS may be considered as an alternative to CEA if the rate of procedure-related stroke or death can be kept below 3% or 6% for asymptomatic and symptomatic stenosis, respectively.

CONCLUSION

Further studies are needed so that better selection criteria can be developed for individually tailored treatment.

[Update carotid artery stenosis]

Stenosis of the extracranial carotid artery is a treatable cause of ischemic stroke and can reliably be detected and graded by vascular ultrasound. The differentiation between symptomatic and asymptomatic stenosis, the perioperative risk and the estimated life expectancy of the patient guide the therapy. Therapy is based on an optimal treatment of cardiovascular risk factors and antiplatelet drugs. Revascularization using surgical carotid endarterectomy is efficient for the prevention of stroke in patients with a high grade symptomatic stenosis. Endovascular therapy using stent-protected angioplasty of the carotid artery is an alternative in patients with a higher surgical risk with low complication rates when performed in experienced centres. Patients with asymptomatic carotid artery stenosis are primarily treated conservatively and revascularization is indicated in patients with a low surgical and global cardiovascular risk.

Risk of intracerebral aneurysm rupture during carotid revascularization

OBJECTIVE

Robust guidelines exist for the treatment of carotid stenosis and intracranial aneurysms independently, however, the management of tandem carotid stenosis and intracranial aneurysms remains uncertain. Although the prevalence of tandem pathologies is small (1.9%-3.2%), treating carotid stenosis can alter intracranial hemodynamics potentially predisposing to aneurysm rupture. In this review, our aim was to assess the safety of intervention in this cohort, by analyzing outcomes from the published literature.

METHODS

The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to conduct the review. Articles from 1947 to 2012 were searched using EMBASE Classic and EMBASE (November, 1947 -March, 2012) and Ovid MEDLINE(R) In-Process and other NonIndexed Citations and Ovid MEDLINE(R) on Ovid SP, http://ClinicalTrials.gov, http://controlled-trials.com and the Cochrane review database using a predefined search strategy.

RESULTS

One hundred forty-one patients from 27 articles were included. Interventions ranged from single (n=104, 74%), staged (n=26, 18%) to simultaneous procedures (n=11, 8%). The largest cohort of patients was treated by carotid endarterectomy alone (n=92, 66%). The majority of patients presented with a symptomatic carotid stenosis and an asymptomatic ipsilateral intracranial aneurysm (n=70, 50%). Five subarachnoid hemorrhages occurred (4% [5/140], three within 30 days of the procedure and two thereafter) of which two were fatal. All five occurred in patients who underwent carotid endarterectomy as a single procedure (5%). Two of the five patients presented with ruptured posterior communicating artery aneurysms.

CONCLUSIONS

Published reports of perioperative aneurysm rupture are rare in individuals with tandem carotid stenosis and intracranial aneurysms. This is the first analysis of all published cases. However, it is limited by the small number of studies and the possible underreporting due to publication bias and underdiagnosis where angiography was not performed. Although we report a low incidence of subarachnoid hemorrhage, analysis of registry data with a larger cohort is warranted to confirm these findings.

Modelling the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis5

Background

The aim of this study was to model the cost-effectiveness of carotid endarterectomy for asymptomatic stenosis versus medical therapy based on 10-year data from the Asymptomatic Carotid Surgery Trial (ACST).

Methods

This was a cost–utility analysis based on clinical effectiveness data from the ACST with UK-specific costs and stroke outcomes. A Markov model was used to calculate the incremental cost-effectiveness ratio (ICER, or cost per additional quality-of-life year) for a strategy of early endarterectomy versus medical therapy for the average patient and published subgroups. An exploratory analysis considered contemporary event rates.

Results

The ICER was £ 7584 per additional quality-adjusted life-year (QALY) for the average patient in the ACST. At thresholds of £ 20 000 and £ 30 000 there was a 74 and 84 per cent chance respectively of early endarterectomy being cost-effective. The ICER for men below 75 years of age was £ 3254, and that for men aged 75 years or above was £ 71 699. For women aged under 75 years endarterectomy was less costly and more effective than medical therapy; for women aged 75 years or more endarterectomy was less effective and more costly than medical therapy. At contemporary perioperative event rates of 2·7 per cent and background any-territory stroke rates of 1·6 per cent, early endarterectomy remained cost-effective.

Conclusion

In the ACST, early endarterectomy was predicted to be cost-effective in those below 75 years of age, using a threshold of £ 20 000 per QALY. If background any-territory stroke rates fell below 1 per cent per annum, early endarterectomy would cease to be cost-effective.

Percutaneous transluminal balloon angioplasty and stenting for carotid artery stenosis

BACKGROUND

Endovascular treatment by transluminal balloon angioplasty or stent insertion may be a useful alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004 and 2007.

OBJECTIVES

To assess the benefits and risks of endovascular treatment compared with carotid endarterectomy or medical therapy in patients with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched January 2012) and the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 4), MEDLINE (1950 to January 2011), EMBASE (1980 to January 2011) and Science Citation Index (1945 to January 2011). We also searched ongoing trials registers (January 2011) and reference lists and contacted researchers in the field.

SELECTION CRITERIA

Randomised trials comparing endovascular treatment (including balloon angioplasty or stenting) with endarterectomy or medical therapy for symptomatic or asymptomatic atherosclerotic carotid stenosis.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endovascular treatment as the reference group. We quantified heterogeneity using the I(2) statistic.

MAIN RESULTS

We included 16 trials involving 7572 patients. In patients with symptomatic carotid stenosis at standard surgical risk, endovascular treatment was associated with a higher risk of the following outcome measures occurring between randomisation and 30 days after treatment than endarterectomy: death or any stroke (the primary safety outcome) (OR 1.72, 95% CI 1.29 to 2.31, P = 0.0003; I(2) = 27%), death or any stroke or myocardial infarction (OR 1.44, 95% CI 1.15 to 1.80, P = 0.002; I(2) = 7%), and any stroke (OR 1.81, 95% CI 1.40 to 2.34, P < 0.00001;I(2) = 12%). The OR for the primary safety outcome was 1.16 (95% CI 0.80 to 1.67) in patients < 70 years old and 2.20 (95% CI 1.47 to 3.29) in patients ≥ 70 years old (interaction P = 0.02).The rate of death or major or disabling stroke did not differ significantly between treatments (OR 1.28, 95% CI 0.93 to 1.77, P = 0.13; I(2) = 0%). Endovascular treatment was associated with lower risks of myocardial infarction (OR 0.44, 95% CI 0.23 to 0.87, P = 0.02; I(2) = 0%), cranial nerve palsy (OR 0.08, 95% CI 0.05 to 0.14, P < 0.00001; I(2) = 0%) and access site haematomas (OR 0.37, 95% CI 0.18 to 0.77, P = 0.008; I(2) = 27%).The combination of death or any stroke up to 30 days after treatment or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.39, 95% CI 1.10 to 1.75, P = 0.005; I(2) = 0%), but the rate of ipsilateral stroke after the peri-procedural period did not differ between treatments (OR 0.93, 95% CI 0.60 to 1.45, P = 0.76; I(2) = 0%).Restenosis during follow-up was more common in patients receiving endovascular treatment than in patients assigned surgery (OR 2.41, 95% CI 1.28 to 4.53, P = 0.007; I(2) = 55%). In patients with asymptomatic carotid stenosis, treatment effects on the primary safety (OR 1.71, 95% CI 0.78 to 3.76, P = 0.18; I(2) = 0%) and combined safety and efficacy outcomes (OR 1.75, 95% CI 0.92 to 3.33, P = 0.09; I(2) = 0%) were similar to symptomatic patients, but differences between treatments were not statistically significant. Among patients not suitable for surgery, the rate of death or any stroke between randomisation and end of follow-up did not differ significantly between endovascular treatment and medical care (OR 0.22, 95% CI 0.01 to 7.92, P = 0.41; I(2)= 79%).

AUTHORS' CONCLUSIONS

Endovascular treatment is associated with an increased risk of peri-procedural stroke or death compared with endarterectomy. However, this excess risk appears to be limited to older patients. The longer term efficacy of endovascular treatment and the risk of restenosis are unclear and require further follow-up of existing trials. Further trials are needed to determine the optimal treatment for asymptomatic carotid stenosis.

Carotid artery stenting: a clinical update

PURPOSE OF REVIEW

Carotid endarterectomy (CEA) has been shown to prevent stroke in patients with severe carotid stenosis. Carotid artery stenting (CAS) has emerged as a less invasive alternative technique. Data regarding comparative effectiveness of CAS and CEA are now available and merit review.

RECENT FINDINGS

Four large randomized controlled trials (RCTs) comparing CAS and CEA have shown a higher rate of stroke in symptomatic patients. The largest and most recent trial reported a lower occurrence of myocardial infarction (MI) following CAS and showed overall comparability of CAS to CEA for both symptomatic and asymptomatic patients. Despite methodological differences, these RCTs are consistent in finding an interaction of patient age with outcomes. In younger patients, CAS appears equivalent or superior to CEA if considering the sum of death, stroke, and MI. In elderly patients, CEA appears to have a lower complication rate. For asymptomatic patients, reduction in event rates with current medical therapy may render previous trial results invalid.

SUMMARY

CAS is an alternative to CEA in patients requiring carotid intervention. Comparison of both CAS and CEA with contemporary medical management will also be required before recommendations can be made regarding the optimal treatment of patients with asymptomatic carotid stenoses.

Evidence-based treatment of carotid artery stenosis

Carotid atheromatous disease is an important cause of stroke. Carotid endarterectomy (CEA) is a well-established option for reducing the risk of subsequent stroke due to symptomatic stenosis (> 50%). With adequately low perioperative risk (< 3%) and sufficient life expectancy, CEA may be used for asymptomatic stenosis (> 60%). Recently, carotid angioplasty and stent placement (CAS) has emerged as an alternative revascularization technique. Trial design considerations are discussed in relation to trial results to provide an understanding of why some trials were considered positive whereas others were not. This review then addresses both the original randomized studies showing that CEA is superior to best medical management and the newer studies comparing the procedure to stent insertion in both symptomatic and asymptomatic populations. Additionally, recent population-based studies show that improvements in best medical management may be lowering the stroke risk for asymptomatic stenosis. Finally, the choice of revascularization technique is discussed with respect to symptom status. Based on current evidence, CAS should remain limited to specific indications.