Stenting versus endarterectomy for treatment of carotid-artery stenosis

Experimental determination of circumferential properties of fresh carotid artery plaques

Carotid endarterectomy (CEA) is currently accepted as the gold standard for interventional revascularisation of diseased arteries belonging to the carotid bifurcation. Despite the proven efficacy of CEA, great interest has been generated in carotid angioplasty and stenting (CAS) as an alternative to open surgical therapy. CAS is less invasive compared with CEA, and has the potential to successfully treat lesions close to the aortic arch or distal internal carotid artery (ICA). Following promising results from two recent trials (CREST; Carotid revascularisation endarterectomy versus stenting trial, and ICSS; International carotid stenting study) it is envisaged that there will be a greater uptake in carotid stenting, especially amongst the group who do not qualify for open surgical repair, thus creating pressure to develop computational models that describe a multitude of plaque models in the carotid arteries and their reaction to the deployment of such interventional devices. Pertinent analyses will require fresh human atherosclerotic plaque material characteristics for different disease types. This study analysed atherosclerotic plaque characteristics from 18 patients tested on site, post-surgical revascularisation through endarterectomy, with 4 tissue samples being excluded from tensile testing based on large width-length ratios. According to their mechanical behaviour, atherosclerotic plaques were separated into 3 grades of stiffness. Individual and group material coefficients were then generated analytically using the Yeoh strain energy function. The ultimate tensile strength (UTS) of each sample was also recorded, showing large variation across the 14 atherosclerotic samples tested. Experimental Green strains at rupture varied from 0.299 to 0.588 and the Cauchy stress observed in the experiments was between 0.131 and 0.779 MPa. It is expected that this data may be used in future design optimisation of next generation interventional medical devices for the treatment and revascularisation of diseased arteries of the carotid bifurcation.

Transient ischaemic attack clinics and management of transient ischaemic attacks

PURPOSE OF REVIEW

The aim is to review transient ischaemic attack (TIA) clinics, other service delivery models, and current TIA management.

RECENT FINDINGS

Urgent assessment of TIA patients by stroke specialist services reduces stroke risk and is cost-effective. Almost one-third of TIA patients wait more than 24 h before presenting to medical attention, with delay associated with higher stroke risk. Risk stratification following suspected TIA may be performed by clinical assessment of individual patient characteristics, combined with the validated ABCD2 score (pre-investigation), and the ABCD3-I score (postinvestigation) in secondary care settings. Brain MRI and transcranial Doppler ultrasound add information related to vascular territory, TIA mechanism, and prognosis. Variability in systolic blood pressure in treated and untreated patients is an important predictor of stroke risk, independently of mean blood pressure.

SUMMARY

Daily specialist-provided TIA services delivered in clinic or inpatient settings have proven efficacy for stroke prevention. In addition, a rapid-access, clinic-based service is associated with cost savings and reduced hospital bed-day utilization after TIA.

Patient preference survey in the management of asymptomatic carotid stenosis

OBJECTIVES

Carotid stenosis accounts for 20% of ischemic strokes and can be managed with pharmacotherapy alone or in conjunction with carotid endarterectomy or stenting. The management of asymptomatic carotid stenosis is controversial amongst physicians. The aim of this study was to explore patient preferences for the potential management options using a standardized scenario to minimize clinician bias. These data will then be used to facilitate comparison with existing published data on physicians' preferences in the management of asymptomatic carotid stenosis.

METHODS

A patient information booklet and questionnaire was developed, validated, and distributed to patients who were identified as candidates for carotid screening duplex based on the presence of peripheral arterial, coronary, or aneurismal disease. Patients were asked to imagine their duplex revealed a 70% unilateral carotid stenosis. Five-year stroke or death risks of 11% were quoted for best medical therapy. The perioperative stroke or death rates quoted were 3% for endarterectomy and 3% to 5% for stenting, based on best current evidence. No physician interaction was allowed to minimize clinician bias. Responses for treatment preference and reasoning were analyzed using appropriate statistical methods. Results from this survey were then compared with a previously published poll of physician preference.

RESULTS

One hundred two questionnaires were analyzed with a 94% response rate: 48% chose pharmacotherapy alone, 30% selected carotid endarterectomy, and 22% opted for stenting. The preference for pharmacotherapy alone over either intervention, and for endarterectomy, over stenting was consistent in subgroup analyses by age, gender, prior stroke, family history of stroke, and smoking status.

CONCLUSION

In this scenario, patients were split equally between medical and surgical treatment of asymptomatic carotid stenosis. This was identical to a recent poll of physicians. Tools for risk assessment and the results of the SPACE2, ACST2, and ACT1 trials would benefit patients and physicians making this important treatment decision.

Carotid Artery Stenting Versus Carotid Endarterectomy

Background and Purpose—

The comparison between carotid endarterectomy and carotid artery stenting (CAS) remains a debated field, especially in the context of long-term outcomes.

Methods—

Concerning the short-term (30-day) analysis, the numbers of outcomes per arm were abstracted, whereas outcomes per arm and hazard ratios were abstracted for long-term (≥1-year) results.

Results—

Thirteen randomized trials (3723 carotid endarterectomy and 3754 CAS patients) were eligible. Regarding short-term outcomes, CAS was associated with elevated risk for stroke and “death or stroke.” CAS also exhibited a marginal trend toward higher death and “death or disabling stroke” rates. Carotid endarterectomy presented with higher rates of myocardial infarction and cranial nerve injury. Concerning long-term outcomes, CAS was associated with higher rates of stroke (pooled OR, 1.37; 95% CI, 1.13 to 1.65) and “death or stroke” (pooled OR, 1.25; 95% CI, 1.06 to 1.48). These findings were replicated at the level of pooled hazard ratios and marginally regarding secondary preventive efficacy. The difference in long-term stroke rates was particularly sizeable in patients >68 years, but little difference in rates was observed in those <68 years. No statistically significant heterogeneity became evident. Metaregression did not reveal any significant modifying effect mediated by symptomatic/asymptomatic status, distal protection, early termination of trials, area of study origin, or CAS learning curve.

Conclusions—

This meta-analysis points to the significantly less frequent stroke events after carotid endarterectomy at the long-term context. The outcomes of carotid endarterectomy seem superior to CAS, but there may be subgroups, particularly younger patients, in whom the results seem equivalent.

Safety of stenting and endarterectomy by symptomatic status in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST)

BACKGROUND AND PURPOSE

The safety of carotid artery stenting (CAS) and carotid endarterectomy (CEA) has varied by symptomatic status in previous trials. The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) data were analyzed to determine safety in symptomatic and asymptomatic patients.

METHODS

CREST is a randomized trial comparing safety and efficacy of CAS versus CEA in patients with high-grade carotid stenoses. Patients were defined as symptomatic if they had relevant symptoms within 180 days of randomization. The primary end point was stroke, myocardial infarction, or death within the periprocedural period or ipsilateral stroke up to 4 years.

RESULTS

For 1321 symptomatic and 1181 asymptomatic patients, the periprocedural aggregate of stroke, myocardial infarction, and death did not differ between CAS and CEA (5.2% versus 4.5%; hazard ratio, 1.18; 95% CI, 0.82 to 1.68; P=0.38). The stroke and death rate was higher for CAS versus CEA (4.4% versus 2.3%; hazard ratio, 1.90; 95% CI, 1.21 to 2.98; P=0.005). For symptomatic patients, the periprocedural stroke and death rates were 6.0%±0.9% for CAS and 3.2%±0.7% for CEA (hazard ratio, 1.89; 95% CI, 1.11 to 3.21; P=0.02). For asymptomatic patients, the stroke and death rates were 2.5%±0.6% for CAS and 1.4%±0.5% for CEA (hazard ratio, 1.88; 95% CI, 0.79 to 4.42; P=0.15). Rates were lower for those aged <80 years.

CONCLUSIONS

There were no significant differences between CAS versus CEA by symptomatic status for the primary CREST end point. Periprocedural stroke and death rates were significantly lower for CEA in symptomatic patients. However, for both CAS and CEA, stroke and death rates were below or comparable to those of previous randomized trials and were within the complication thresholds suggested in current guidelines for both symptomatic and asymptomatic patients.

Carotid artery stenting without angioplasty and cerebral protection: a single-center experience with up to 7 years' follow-up

BACKGROUND AND PURPOSE

The use of cerebral protection during CAS in the treatment of carotid artery disease is matter of controversy. The purpose of this study was to evaluate the outcome of CASWBAP in a large cohort of patients, with ≤7 years' follow-up.

MATERIALS AND METHODS

Two hundred thirty-six patients with 255 symptomatic carotid stenoses and/or with high-risk-morphology plaques of >50% and asymptomatic plaques of >70% were prospectively identified. Patients underwent neurologic and carotid US examination before the procedure and during follow-up at 1, 3, 6, and 12 months and annually thereafter. Plain films of the neck were obtained immediately after the procedure and then at 1 and 3 months.

RESULTS

Technical success was achieved in 253/255 (99%) patients. Primary stent placement was successful in 248/253 (98%) patients. Neurologic periprocedural complications within 30 days included 1 (0.4%) nondisabling stroke, 1 (0.4%) disabling stroke, 11 (4.3%) TIAs, and 1 (0.4%) death. The mean duration of follow-up was 23 ± 1.4 months (range, 3-84 months). During the follow-up period, there were 9 additional deaths (7 unrelated to the carotid disease and 2 stroke-related) and 2 strokes (in other vascular territories). The degree of stenosis decreased from a mean of 82% before the procedure to a mean of 30% immediately after. During follow-up, 38 (14.8%) angioplasties were performed due to restenosis in 19 (7.4%) patients, lack of stent expansion in 14 (5.4%), or both in 5 (1.9%).

CONCLUSIONS

CASWBAP is effective and safe with a low incidence of periprocedural complications, providing satisfactory long-term clinical results.

Carotid artery disease and stenting: insights from recent clinical trials

OPINION STATEMENT

Cerebrovascular disease remains a leading cause of morbidity, mortality, and health care expenditure in the United States. Approximately 80% of strokes are ischemic in origin, with 20% to 25% due to atherosclerotic disease of the carotid artery. It is well established that untreated, symptomatic carotid stenosis confers a 25% risk of stroke within 2 years, and that asymptomatic carotid stenosis > 60% is associated with an 11% stroke risk at 5 years. Over the past six decades, surgical revascularization with carotid endarterectomy, when performed by experienced surgeons, has been demonstrated to be effective in reducing stroke risk in patients with severe stenosis. During the same time, medical therapy has improved considerably, and endovascular therapy with carotid angioplasty and stenting has emerged as an important alternative strategy that may play a significant role in reducing the risk of stroke in patients with carotid disease. In this review, we examine the current evidence regarding optimal medical therapy, endarterectomy, and stenting for the management of patients with carotid stenosis. Armed with these data, we may tailor our approach to optimize care based on patient- and lesion-specific considerations.

Controversies in neurology: asymptomatic carotid stenosis--intervention or just stick to medical therapy. The argument for carotid endarterectomy

Patients with a significant carotid stenosis are at an increased risk of suffering from a potentially fatal or disabling stroke. The current management strategies available to a patient with an asymptomatic carotid stenosis are either medical therapy alone, or in combination with either carotid endarterectomy, or carotid angioplasty and stenting. Medical therapy alone can reduce the incidence of stroke in general, but whether there is any reduction in stroke attributable to a significant carotid stenosis is less clear. Carotid endarterectomy, on the other hand, has been shown to reduce the incidence of ipsilateral ischaemic stroke in both symptomatic and asymptomatic patients, with the benefits extending into the long-term. Carotid angioplasty and stenting is a newer technique with the benefit of being minimally invasive. The results of trials comparing the technique to endarterectomy have had conflicting results, and the results of large multi-centre trials are awaited. Currently the safest strategy for a patient with a significant asymptomatic carotid stenosis consists of optimal medical therapy with carotid endarterectomy for those less than 75 years of age, who are suitable for surgery.

Heart disease and stroke statistics--2011 update: a report from the American Heart Association

Each year, the American Heart Association (AHA), in conjunction with the Centers for Disease Control and Prevention, the National Institutes of Health, and other government agencies, brings together the most up-to-date statistics on heart disease, stroke, other vascular diseases, and their risk factors and presents them in its Heart Disease and Stroke Statistical Update. The Statistical Update is a valuable resource for researchers, clinicians, healthcare policy makers, media professionals, the lay public, and many others who seek the best national data available on disease morbidity and mortality and the risks, quality of care, medical procedures and operations, and costs associated with the management of these diseases in a single document. Indeed, since 1999, the Statistical Update has been cited more than 8700 times in the literature (including citations of all annual versions). In 2009 alone, the various Statistical Updates were cited ≈1600 times (data from ISI Web of Science). In recent years, the Statistical Update has undergone some major changes with the addition of new chapters and major updates across multiple areas. For this year’s edition, the Statistics Committee, which produces the document for the AHA, updated all of the current chapters with the most recent nationally representative data and inclusion of relevant articles from the literature over the past year and added a new chapter detailing how family history and genetics play a role in cardiovascular disease (CVD) risk. Also, the 2011 Statistical Update is a major source for monitoring both cardiovascular health and disease in the population, with a focus on progress toward achievement of the AHA’s 2020 Impact Goals. Below are a few highlights from this year’s Update.

Embolic complications after carotid artery stenting or carotid endarterectomy are associated with tissue characteristics of carotid plaques evaluated by magnetic resonance imaging

BACKGROUND

Unstable carotid plaques are associated with an increased incidence of embolic complications after carotid artery stenting (CAS) or carotid endarterectomy (CEA). The aim of this study was to elucidate the relationship between the tissue components of carotid plaques and the incidence of new ipsilateral silent ischemic lesions (NISIL) after CAS or CEA.

METHODS

We performed CAS in 56 patients and CEA in 25 patients. We also performed quantitative analyses of carotid plaque characteristics before treatment using T1 weighted black-blood magnetic resonance imaging (BB-MRI). The signal intensity ratio (SIR) was defined as the ratio of signal intensity evaluated by BB-MRI in carotid plaques to that of sternocleidomastoid muscle. According to criteria that we and other investigators previously reported, an SIR ≥ 1.25 was defined as "high". NISIL were evaluated by diffusion-weighted imaging of MRI before and after CAS or CEA.

RESULTS

In the high SIR group, the incidence of NISIL was significantly greater after CAS than after CEA (61% vs 13%, respectively, p=0.006), whereas there were no significant difference in NISIL after the two procedures when the SIR was <1.25 (21% vs 0%). In multivariate regression analysis, the independent predictors of NISIL were CAS (p=0.002), symptomatic stenosis (p=0.036) and the SIR (p=0.049).

CONCLUSIONS

Noninvasive quantitative tissue characterization of carotid plaques using BB-MRI is useful to determine the indication for CAS.

Carotid artery stenting, endarterectomy, or medical treatment alone: the debate is not over

The management of carotid artery stenosis reduces the risk of stroke and its related deaths. Management options include risk factor modification and medical therapy, carotid endarterectomy (CEA), and carotid artery stenting (CAS). Although several randomized controlled trials (RCTs), mostly conducted in late-1980s and mid-1990s, have proved CEA to be effective in the prevention of ipsilateral ischemic events in selected patients with carotid artery stenosis, aggressive risk factor modification and medical therapy with recently introduced antiplatelet agents, statins, and more effective antihypertensive medications may have reduced compelling indications for immediate surgery in asymptomatic populations. Also recently, due to improvements in percutaneous techniques and carotid stents, CAS has received wide attention as a potential alternative to CEA. Herein, we review the recent data on the management options of carotid artery stenosis and seek to identify the most appropriate treatment strategy in selected patients with carotid artery stenosis.

Does current practice in the United States of carotid artery stent placement benefit asymptomatic octogenarians?

BACKGROUND AND PURPOSE

CAS or CEA for asymptomatic carotid stenosis is the focus of recently completed and ongoing randomized clinical trials. These techniques are widely utilized outside the setting of such trials. Therefore, our goal was to analyze the in-hospital stroke or death rates after CAS or CEA for asymptomatic stenosis that reflect current nationwide practice.

MATERIALS AND METHODS

Using sample-weighted ANOVA, we analyzed records from the 2006 and 2007 NIS, which are nationally representative cohorts for asymptomatic CAS or CEA. The primary outcome measure was a composite end point of in-hospital stroke, cardiac complications, or death. In-hospital stroke or death was a secondary outcome measure.

RESULTS

For ≥ 80 years of age, the in-hospital stroke, cardiac complications, or death rate after CAS was 4.9%, while the complication rate after CEA was 3.8%. The stroke or death rate after CAS was 2.7% for ≥ 80 years of age and was 1.5% after CEA for the same age group. Multivariate analysis showed that age (OR, 1.12; 95% CI, 0.97-1.3; P < .07) or procedure (OR, 1.12; 95% CI, 0.99-1.27; P < .14) was not associated with the composite end point of in-hospital stroke, cardiac complications, or death. In contrast, CAS (OR, 1.28; 95% CI, 1.03-1.58) and female sex (OR, 1.23; 95% CI, 1.04-1.45) were independently associated with in-hospital stroke or death following asymptomatic carotid revascularization. Hospital charges and hospital costs were lower for CEA than CAS (2007 costs: $7779 versus $12,104).

CONCLUSIONS

CAS is independently associated with increased in-hospital stroke or death (excluding cardiac complications from the composite outcome). In those ≥ 80 years of age, CAS as currently performed may not improve the natural history of asymptomatic carotid stenosis, because in-hospital stroke or death rates following CAS approached 3% in this group.