Carotid Artery Endarterectomy Research Articles

74-year-old man with left main and carotid artery disease - how life can change plans.

An unexpected incident or rapid deterioration of a patient's condition may require optimal adaptation of the treatment to the current state of the patient. We present a case of a 74-year-old man with significant left main coronary artery stenosis and tight stenoses of both carotid arteries. The case was initially qualified for bypass grafting with accompanying carotid artery endarterectomy, but an unexpected accident changed our way of treatment. Three days after angiography the patient suffered an ischemic stroke. We held a multidisciplinary meeting of the “Neuro-Vascular-Heart Team” and decided to treat the patient percutaneously.

Transulnar carotid artery stent placement

Carotid artery stenting (CAS) has increased in popularity as an alternative to carotid artery endarterectomy for the treatment of significant carotid artery stenosis. The access site is predominantly the femoral artery, with radial or brachial access used less often. Here, we describe a case of CAS after failure of brachial access. Transulnar CAS was performed successfully without complications. Transulnar access represents an additional option in a patient undergoing CAS when conventional femoral, brachial, and radial arteries are not applicable.

Pre-procedural Risk Quantification for Carotid Stenting Using the CAS Score: A Report From the NCDR CARE Registry

We developed and internally validated a risk score to predict in-hospital stroke or death after carotid artery stenting (CAS). A tool that accurately assesses CAS risk could aid clinical decision making and improve patient selection. Patients undergoing CAS without acute evolving stroke from April 2005 through June 2011 as part of the NCDR Carotid Artery Revascularization and Endarterectomy (CARE) Registry were included. In-hospital stroke or death was modeled using logistic regression with 35 candidate variables. Internal validation was achieved with bootstrapping, and model discrimination and calibration were assessed. A total of 271 (2.4%) primary endpoint events occurred during 11,122 procedures. Independent predictors of stroke or death included impending major surgery, previous stroke, age, symptomatic lesion, atrial fibrillation, and absence of previous ipsilateral carotid endarterectomy. The model was well calibrated with moderate discriminatory ability (C-statistic: 0.71) overall, and within symptomatic (C-statistic: 0.68) and asymptomatic (C-statistic: 0.72) subgroups. The inclusion of available angiographic variables did not improve model performance (C-statistic: 0.72, integrated discrimination improvement 0.001; p = 0.21). The NCDR CAS score was developed to support prospective risk quantification. The NCDR CAS score, comprising 6 clinical variables, predicts in-hospital S/D after CAS. This tool may be useful to assist clinicians in evaluating optimal management, share more accurate pre-procedural risks with patients, and improve patient selection for CAS.

Selection of Carotid Artery Stenting or Endarterectomy Based on Magnetic Resonance Plaque Imaging Reduced Periprocedural Adverse Events

The aim of this study was to elucidate the impact of treatment selection, either carotid stenting or endarterectomy, based on preoperative magnetic resonance (MR) plaque imaging on periprocedural events. A total of 205 consecutive patients with high-grade carotid artery stenosis scheduled for elective revascularization with stenting or endarterectomy were retrospectively analyzed. In period 1, 95 patients were treated regardless of preoperative plaque imaging. In period 2, 110 patients received time of flight MR angiography, and endarterectomy was selected when a high-intensity signal in the plaque was observed on MR angiography because it indicated an unstable plaque. Periprocedural clinical results and outcome at 30 days were analyzed. In period 1, 5 patients (5.3%) were treated with endarterectomy and the other 90 patients (94.7%) were treated with stenting. In period 2, 35 patients (31.8%) were treated with endarterectomy and the other 75 patients (68.2%) were treated with stenting. Periprocedural adverse events, including any stroke, myocardial infarction, or death, were significantly more frequent in period 1 than in period 2 (9.5% v 1.8%; P = .034). Ischemic stroke was significantly reduced from period 1 to period 2 (7.4% v 0.9%; P = .043). Multivariate logistic regression analysis revealed "treatment selection by plaque imaging" was the only factor identified as an independent predictor of periprocedural events (P = .043). Treatment selection based on preoperative plaque imaging appears useful for reducing periprocedural events of carotid artery revascularizations.

Restenosis after carotid artery stenting and endarterectomy: a secondary analysis of CREST, a randomised controlled trial

In the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), the composite primary endpoint of stroke, myocardial infarction, or death during the periprocedural period or ipsilateral stroke thereafter did not differ between carotid artery stenting and carotid endarterectomy for symptomatic or asymptomatic carotid stenosis. A secondary aim of this randomised trial was to compare the composite endpoint of restenosis or occlusion. Patients with stenosis of the carotid artery who were asymptomatic or had had a transient ischaemic attack, amaurosis fugax, or a minor stroke were eligible for CREST and were enrolled at 117 clinical centres in the USA and Canada between Dec 21, 2000, and July 18, 2008. In this secondary analysis, the main endpoint was a composite of restenosis or occlusion at 2 years. Restenosis and occlusion were assessed by duplex ultrasonography at 1, 6, 12, 24, and 48 months and were defined as a reduction in diameter of the target artery of at least 70%, diagnosed by a peak systolic velocity of at least 3·0 m/s. Studies were done in CREST-certified laboratories and interpreted at the Ultrasound Core Laboratory (University of Washington). The frequency of restenosis was calculated by Kaplan-Meier survival estimates and was compared during a 2-year follow-up period. We used proportional hazards models to assess the association between baseline characteristics and risk of restenosis. Analyses were per protocol. CREST is registered with ClinicalTrials.gov, number NCT00004732. 2191 patients received their assigned treatment within 30 days of randomisation and had eligible ultrasonography (1086 who had carotid artery stenting, 1105 who had carotid endarterectomy). In 2 years, 58 patients who underwent carotid artery stenting (Kaplan-Meier rate 6·0%) and 62 who had carotid endarterectomy (6·3%) had restenosis or occlusion (hazard ratio [HR] 0·90, 95% CI 0·63-1·29; p=0·58). Female sex (1·79, 1·25-2·56), diabetes (2·31, 1·61-3·31), and dyslipidaemia (2·07, 1·01-4·26) were independent predictors of restenosis or occlusion after the two procedures. Smoking predicted an increased rate of restenosis after carotid endarterectomy (2·26, 1·34-3·77) but not after carotid artery stenting (0·77, 0·41-1·42). Restenosis and occlusion were infrequent and rates were similar up to 2 years after carotid endarterectomy and carotid artery stenting. Subsets of patients could benefit from early and frequent monitoring after revascularisation. National Institute of Neurological Disorders and Stroke and Abbott Vascular Solutions.

Cost-effectiveness of carotid artery stent placement versus endarterectomy in patients with carotid artery stenosis

The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) demonstrated that the risk of the primary composite outcome of stroke, myocardial infarction (MI), or death did not differ significantly in patients with an average surgical risk undergoing carotid artery stenting (CAS) and those undergoing carotid endarterectomy (CEA). However, the cost associated with CAS may limit its broad applicability. The authors' goal in this paper was to determine the cost-effectiveness of CAS with an embolic-protection device versus CEA in patients with moderate to severe carotid artery stenosis who are at average surgical risk. The probability of the primary outcome was obtained from the results of the CREST trial. The quality-adjusted life years (QALYs) associated with each treatment modality were estimated by adjusting for the incidence of each quality-adjusted outcome (QALY weights of ipsilateral stroke, MI, death, and postprocedure QALYs). The total cost associated with each intervention was derived from hospitalization cost and cost associated with primary outcomes including stroke, MI, and death in each group. Costs are expressed in US dollars accounting for inflation up to October 2010. Incremental cost-effectiveness ratios (ICERs) were estimated for the 4-year period after the procedure. All values are expressed as means and 95% confidence intervals. The estimated net costs for patients after treatment with CAS and CEA after consideration of the primary outcome were $18,335 and $13,276, respectively, from the definitive presimulation analysis. Postsimulation values were $19,210 (range $18,264-$20,156) and $14,080 (range $13,076-$15,084), respectively. Overall, QALYs for the CAS and CEA groups were 0.712 and 0.702, respectively (ranging from 0.0 [death] to 0.815 [no adverse events]). The estimated ICER for CAS versus CEA treatment was $229,429. Although the CREST demonstrated equivalent results with CAS (compared with CEA) in patients at average surgical risk with severe carotid artery stenosis, broad applicability of CAS might be limited by the higher cost associated with this procedure.

Comparison of carotid endarterectomy and stenting in real world practice using a regional quality improvement registry

Carotid artery stenting (CAS) vs endarterectomy (CEA) remains controversial and has been the topic of recent randomized controlled trials. The purpose of this study was to compare the practice and outcomes of CAS and CEA in a real world setting. This is a retrospective analysis of 7649 CEA and 430 CAS performed at 17 centers from 2003 to 2010 within the Vascular Study Group of New England (VSGNE). The primary outcome measures were (1) any in-hospital stroke or death and (2) any stroke, death, or myocardial infarction (MI). Patients undergoing CEA in conjunction with cardiac surgery were excluded. Multivariate logistic regression was performed to identify predictors of stroke or death in patients undergoing CAS. CEA was performed in 17 centers by 111 surgeons, while CAS was performed in 6 centers by 30 surgeons and 8 interventionalists. Patient characteristics varied by procedure. Patients undergoing CAS had a higher prevalence of coronary artery disease, congestive heart failure, diabetes, and prior ipsilateral CEA. Embolic protection was used in 97% of CAS. Shunts were used in 48% and patches in 86% of CEA. The overall in-hospital stroke or death rate was higher among patients undergoing CAS (2.3% vs 1.1%; P = .03). Overall stroke, death, or MI (2.8% CAS vs 2.1% CEA; P = .32) were not different. Asymptomatic patients had similar rates of stroke or death (CAS 0.73% vs CEA 0.89%; P = .78) and stroke, death, or MI (CAS 1.1% vs CEA 1.8%; P = .40). Symptomatic patients undergoing CAS had higher rates of stroke or death (5.1% vs 1.6%; P = .001), and stroke, death, or MI (5.8% vs 2.7%; P = .02). By multivariate analysis, major stroke (odds ratio, 4.5; 95% confidence interval [CI], 1.9-10.8), minor stroke (2.7; CI, 1.5-4.8), prior ipsilateral CEA (3.2, CI, 1.7-6.1), age >80 (2.1; CI, 1.3-3.4), hypertension (2.6; CI, 1.0-6.3), and a history of chronic obstructive pulmonary disease (1.6; CI, 1.0-2.4) were predictors of stroke or death in patients undergoing carotid revascularization. In our regional vascular surgical practices, the overall outcomes of CAS and CEA are similar for asymptomatic patients. However, symptomatic patients treated with CAS are at a higher risk for stroke or death.

Outcome After 7 Years of Carotid Artery Stenting and Endarterectomy in Sweden – Single Centre and National Results

Objectives: The aim was internal vascular centre quality-control measures to compare single-centre results with the national perspective, as well as Analysing the Swedish results from carotid artery stenting (CAS) and comparing a relatively high-volume single centre with the Swedish Vascular Registry (Swedvasc) data. The second aim was to compare CAS and carotid artery endarterectomy (CEA) outcomes for the same 7-year period. Design: Retrospective review of a single high-volume centre (Södersjukhuset (SöS)) (approximately 30 CAS year−1 approximately 90 CEA year−1) versus Swedvasc National data. Materials and methods: All consecutive selective patients treated with CAS at SöS for a stenosis of the internal carotid artery (n = 208) or CEA (n = 552) between 2004 and 2011 were compared with all patients in Swedvasc registered for CAS (n = 258) and CEA (n = 6474). Primary outcome was 30-day frequency of stroke or death. Secondary outcome was stroke/death/acute myocardial infarction (AMI). Results: The 30-day frequency of any stroke or death after CAS at SöS compared to the national data was 2.9% and 7.4%, respectively (P = 0.04). The 30-day AMI/stroke/death frequency was 3.4% and 9.5%, respectively (P = 0.01). After CEA during the same time period, the Swedvasc national data had a 4.4% frequency of 30-day stroke and death and 5.8% for AMI/stroke/death. Conclusions: CAS is not as safe as CEA from a national perspective but our results indicate that a single centre can achieve acceptable results with CAS.

Restenosis Following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy Versus Stenting Trial (IN2-1.001)

Restenosis Following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy Versus Stenting Trial (IN2-1.001)

Restenosis Following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy Versus Stenting Trial (S09.003)

Restenosis Following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy Versus Stenting Trial (S09.003)

Cost-Effectiveness of Carotid-Artery Stent Placement Versus Endarterectomy in Patients with Carotid Stenosis (S09.007)

Cost-Effectiveness of Carotid-Artery Stent Placement Versus Endarterectomy in Patients with Carotid Stenosis (S09.007)

Commentary to ‘Outcome After 7 Years of Carotid Artery Stenting and Endarterectomy in Sweden – Single Centre and National Results’

‘Equipoise’ is a situation described as a “doubt as towhich of two clinical interventions is more beneficial for the patient.” In practice, equipoise mandates that patients may be assigned to different treatment options as long as there is a professional uncertainty about which treatment is superior.1 For carotid revascularisation, uncertainty does not exist while numerous randomised trials have demonstrated the inferiority of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) for stroke prevention in symptomatic patients, especially in patients older than 70 years. Although asymptomatic patients are still under trial, CAS in asymptomatic patients has been associated with approximately double the periprocedural rate of death/stroke compared with CEA. The American College of Surgeons stated that it is “essential that the value and safety of a new procedure is established before it is widely used on patients.”2 Nowadays, the introduction of new surgical devices is mostly driven by commercial enterprise, and most innovative surgical procedures enter practice without regulatory oversight.1 The article by Lindstrom et al. in fact demonstrates the potential detrimental impact on patients when a new surgical procedure is widely introduced at a time of not knowing its safety and efficacy.3 The authors compared the periprocedural outcome in a consecutive series of CAS and CEA from a single high-volume centre (SOS) with data from low-volume centres derived from the Swedvasc national database. The authors conclude, “although not as safe as CEA, a single centre can achieve acceptable resultswith CAS.” The fact that a single hospital has acceptable outcomes with 208 CAS cases over a 7-year time frame does not convince us that CAS can be recommended as the first line of therapy. Moreover, besides not supporting the further application of CAS, this analysis far more indicates what can happen when CAS is applied outside the strict borders of randomised trials, considering the extraordinary result within Swedvasc of a 10.9% (11/101) stroke and death rate after CAS for asymptomatic patients. The three key messages of this report are:

Outcome After 7 Years of Carotid Artery Stenting and Endarterectomy in Sweden – Single Centre and National Results

ObjectivesThe aim was internal vascular centre quality-control measures to compare single-centre results with the national perspective, as well as analysing the Swedish results from carotid artery stenting (CAS) and comparing a relatively high-volume single centre with the Swedish Vascular Registry (Swedvasc) data. The second aim was to compare CAS and carotid artery endarterectomy (CEA) outcomes for the same 7-year period. DesignRetrospective review of a single high-volume centre (Södersjukhuset (SÖS)) (approximately 30 CAS year−1 approximately 90 CEA year−1) versus Swedvasc National data. Materials and methodsAll consecutive selective patients treated with CAS at SÖS for a stenosis of the internal carotid artery (n = 208) or CEA (n = 552) between 2004 and 2011 were compared with all patients in Swedvasc registered for CAS (n = 258) and CEA (n = 6474). Primary outcome was 30-day frequency of stroke or death. Secondary outcome was stroke/death/acute myocardial infarction (AMI). ResultsThe 30-day frequency of any stroke or death after CAS at SÖS compared to the national data was 2.9% and 7.4%, respectively (P = 0.04). The 30-day AMI/stroke/death frequency was 3.4% and 9.5%, respectively (P = 0.01). After CEA during the same time period, the Swedvasc national data had a 4.4% frequency of 30-day stroke and death and 5.8% for AMI/stroke/death. ConclusionsCAS is not as safe as CEA from a national perspective but our results indicate that a single centre can achieve acceptable results with CAS.

Abstract 3: Restenosis following Carotid Artery Stenting and Endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial

Objectives The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) showed no difference in the composite endpoint of stroke, myocardial infarction, or death between carotid artery stenting (CAS) and carotid endarterectomy (CEA) in patients with symptomatic or asymptomatic carotid stenosis (CS). We compared restenosis or occlusion, and repeat revascularization, between CAS and CEA over 2 years of follow-up. Methods Restenosis, occlusion, and repeat revascularization were assessed at 1, 6, 12 and 24 months post-randomization. Hemodynamically significant restenosis (≥70% diameter reduction) was defined by a peak systolic velocity (PSV) ≥300 cm/second on standardized duplex ultrasonography (DUS), occlusion by an absence of flow within the target artery on DUS, and repeat revascularization by any additional procedure (CEA, angioplasty or CAS) performed on the index artery. Studies were performed in CREST-certified laboratories and interpreted in the CREST Ultrasound Core Lab. Patients included in this report were those who received their assigned treatment within 30 days of randomization and had an ultrasound reviewed at the Core Lab (n=2191). Treatment differences were assessed using proportional hazards models adjusting for age, sex, and symptomatic status. Results In the analytic cohort, 1086 patients received CAS and 1105 received CEA. Over 2 years 113 patients developed restenosis, 56 (rate 5.8%) in the CAS group and 57 (rate 5.8%) in the CEA group; and 8 developed an occlusion, 3 (rate 0.3 %) in the CAS group and 5 (rate 0.5%) in the CEA group. The combined restenosis-occlusion rate was 6.0% (n=58) for CAS and 6.3% (n=62) for CEA (HR=0.90, 95% CI=0.63-1.29, p=0.58). Forty-three patients of the 2191 underwent repeat revascularization (20 CAS, 23 CEA, p=0.69) of which 28 had restenosis by our criteria and so were included ( Figure ). Stroke occurred in 13 (4 CAS; 9 CEA) of the 120 patients with restenosis or occlusion; 1 of the 4 CAS strokes occurred after restenosis was detected, and 5 of 9 CEA strokes occurred after restenosis was detected. Conclusions This analysis of carotid restenosis is the largest reported to date from any randomized clinical trial. Restenosis and occlusion were infrequent and similar up to 2 years following CAS or CEA among 2191 patients. The rates of revascularization likewise did not differ between CAS and CEA. Follow-up out to 10 years is ongoing. Figure. Kaplan-Meier curves of restenosis and occlusion over 2 years.

Advances in Stroke

Carotid artery stenting (CAS) has not been shown to be as safe as carotid endarterectomy for treatment of symptomatic extracranial carotid artery stenosis in the immediate postoperative period. However, beyond the postoperative period, data continues to support a role for CAS in selected patients. A large systematic review of 206 individual studies (54 713 total patients) undergoing CAS found the cumulative 30-day risk of stroke or death to be 7.6% in symptomatic and 3.3% in asymptomatic patients.1 Factors associated with increased risk of adverse outcomes in both groups were age 75 years (relative risk [RR] 1.88), hypertension (RR 1.86), and coronary artery disease (RR 1.41). Use of embolic protection devices significantly reduced the risk of stroke or death (RR 0.57). Although reports of adverse events vary widely in the literature, there has been a trend toward overall reduction in risk over the past several years, suggesting that use of embolic protection devices, careful patient selection, and increasing operator experience may be important factors in minimizing risk. The vast majority of these data (97%) are outside the standards of a randomized controlled trial (RCT), emphasizing the need for data from the trials that are currently enrolling patients. Among the larger studies currently enrolling patients are the Carotid Stenting for High Risk Surgical Patients (CHOICE, Abbott Vascular, target 5000 patients), Asymptomatic Carotid Surgery Trial-2 (ACST-2, target 5000 patients), and Stent-Protected Angioplasty in Asymptomatic Carotid Artery Stenosis versus Endarterectomy trial (SPACE-2, target 3640 patients). This year, we received our first update from the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), the largest RCT to date comparing the periprocedural safety and long-term (4 years) efficacy of CAS versus carotid endarterectomy.2 Data from the lead-in phase demonstrated an overall 30-day stroke and death rate of 4.4%. Restenosis rates in the lead-in phase were reported to be 13% with 1.2% of patients requiring repeat revascularization by 1-year follow-up. These numbers compare to restenosis rates of 10.7% and 4.6% in patients undergoing CAS and carotid endarterectomy, respectively, in the SPACE trial3 and 19% of CAS patients in the Stenting and Angioplasty with Protection in Patients at High Risk of Endarterectomy (SAPPHIRE) study. 4 The Carotid Revascularization Using Endarterectomy

Carotid endarterectomy versus stenting: Where do we stand today?

Carotid artery stenosis is the major cause of the stroke associated with ischemic origin and carries increased mortality and morbidity. Since carotid artery endarterectomy (CEA) was first performed in 1950, in conjunction with the advanced technology and increased experience under the guidance of randomized controlled trials, balloon angioplasty and carotid artery stenting, which have similar mortality and morbidity, have become comparable with CEA. Determining the optimal treatment option for each patient is the most important issue in carotid artery stenosis. Today, there have been improvements in technology and recent advances in the cardiovascular sciences. Moreover, there is increased experience, increased attention to patient selection, and a team approach to find the most suitable treatment for the patient. In this review, we briefly discuss the current treatment approaches for carotid artery stenosis under the guidance of the modern studies.

Outcomes After Carotid Artery Stenting and Endarterectomy in the Medicare Population

Outcomes After Carotid Artery Stenting and Endarterectomy in the Medicare Population

Carotid Revascularization Immediately Before Urgent Cardiac Surgery: Practice Patterns Associated With the Choice of Carotid Artery Stenting or Endarterectomy: A Report From the CARE (Carotid Artery Revascularization and Endarterectomy) Registry

We describe characteristics associated with use of endarterectomy (CEA) versus stenting (CAS) in patients before urgent cardiac surgery.The optimal modality of carotid revascularization preceding cardiac surgery is unknown.Retrospective evaluation of the CARE (Carotid Artery Revascularization and Endarterectomy) registry from January 2005 to April 2010 was performed on patients undergoing CEA or CAS preceding urgent cardiac surgery within 30 days. Baseline characteristics were compared, and multivariate adjustment was performed.Of 451 patients who met study criteria, 255 underwent CAS and 196 underwent CEA. Both procedures increased over time to a similar degree (p = 0.18). Patients undergoing CAS had more frequent history of peripheral artery disease (38.2% vs. 26.5%, p < 0.01), neck surgery (5.5% vs. 1.0%, p = 0.01), neck radiation (4.3% vs. 1.0%, p = 0.04), left-main coronary disease (34.8% vs. 23.5%, p < 0.01), neurological events (45.8% vs. 31.3%, p < 0.01), carotid intervention (20.8% vs. 7.6%, p < 0.01), and higher baseline creatinine (1.3 vs. 1.1 mg/dl, p = 0.02). The target carotid arteries of CAS patients were more likely to be symptomatic in the 6 months before revascularization and have restenosis from prior CEA. Patients undergoing CAS had a lower American Society of Anesthesiology grade. Midwest hospitals were less likely to perform CAS than CEA, whereas in the other regions CAS was more common (p < 0.01). Non-Caucasian race, a history of heart failure, previous carotid procedures, prior stroke, left main coronary artery stenosis, lower American Society of Anesthesiology grade, and teaching hospital were independent predictors of patients who would receive CAS.Carotid artery stenting and CEA have increased among patients undergoing urgent cardiac surgery. Patients who underwent CAS had more vascular disease but lower acute pre-surgical risk. Significant regional variation in procedure selection exists.

Carotid Stenting at the Crossroads

STROKE IS A MAJOR CAUSE OF DEATH AND DISABILITY. Approximately 10% to 15% of ischemic strokes are attributable to atherosclerosis of the internal carotid arteries, and there is great interest in surgical and endovascular approaches to stroke prevention. Carotid artery surgery or endarterectomy (CEA) has been the traditional intervention, and carotid angioplasty with stenting (CAS) is the newer percutaneous procedure. Both procedures increase the short-term risk of death or stroke due to the intervention in exchange for a lower long-term risk of stroke. Therefore, the magnitude and balance of the risks and benefits for these procedures are crucial considerations. Patients with symptomatic disease (ie, those who have had a stroke or transient ischemic attack in the past 6-12 months in the distribution of a carotid artery with 50% stenosis) benefit from CEA, which reduces the absolute risk of stroke by 8% per year. Asymptomatic patients (those with carotid occlusive disease without neurological symptoms) have a more modest benefit from CEA (absolute stroke reduction of 0.8%-1% per year). Carotid artery surgery or endarterectomy is considered beneficial only if it can be performed with a 30-day risk of death or stroke of 6% or less among symptomatic patients and 3% or less among those who are asymptomatic. Carotid angioplasty with stenting was originally approved by the US Food and Drug Administration (FDA) in 2004 for patients who were at too high a risk for CEA because of comorbidity or anatomical factors. In October 2004, because of uncertainty about efficacy, Medicare restricted reimbursement for CAS to high-risk symptomatic patients enrolled in postapproval studies. In March 2005, Medicare expanded coverage to allow treatment of high-risk symptomatic patients with carotid stenosis greater than 70% outside of trials using FDAapproved stents and embolic protection devices. The Centers for Medicare & Medicaid Services (CMS) also covers CAS for symptomatic patients with 50% to 70% carotid stenosis and asymptomatic patients with greater than 80% carotid stenosis if the procedure is performed in a postapproval or randomized controlled trial (RCT). Since then, CAS use has increased substantially, with large geographic variations in utilization. The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) compared CAS with CEA for patients with symptomatic and asymptomatic carotid disease. However, debate persists regarding interpretation of the study findings; CAS was equivalent to CEA for the primary composite end point of periprocedural death, stroke, or myocardial infarction or subsequent ipsilateral stroke. Carotid angioplasty with stenting was associated with worse outcomes than CEA for the combined outcome of periprocedural death or stroke or subsequent stroke, the end point used in trials comparing CEA with medical therapy. In May 2011, based on the CREST results, the FDA expanded the indication for CAS to all patients with carotid disease, not just those at high surgical risk. Against this backdrop, the outcomes and use of CAS in real-world practice is of great importance. In this issue of JAMA, Nallamothu and colleagues examine the relationship between operator experience and 30-day mortality rates following CAS using national Medicare administrative data from 24 701 procedures performed by 2339 physicians between 2005 and 2007. The authors found that patients treated by lowest-volume operators ( 6 CAS procedures per year) had an increased odds of death compared with patients treated by high-volume operators ( 24 procedures per year). Low-volume operators were much less likely to use an embolic protection device, an intervention associated with improved outcomes. They also demonstrated a “learning curve” at the individual physician level among the 1792 “later adopters” who started performing CAS after the 2005 CMS cov-

Outcomes After Carotid Artery Stenting and Endarterectomy in the Medicare Population

Carotid artery stenting (CAS) is an alternative to carotid endarterectomy (CEA) for stroke prevention. The value of this therapy relative to CEA remains uncertain. In 10 958 Medicare patients aged 66 years or older between 2004 and 2006, we analyzed in-hospital, 1-year stroke, myocardial infarction, and death rate outcomes and the effects of potential confounding variables. CAS patients (87% were asymptomatic) had a higher baseline risk profile, including having a higher percentage of coronary and peripheral arterial disease, heart failure, and renal failure. In-hospital stroke rate (1.9% CAS versus 1.4% CEA; P=0.14) and mortality (CAS 0.9% versus 0.6% CEA; P=0.20) were similar. By 1 year, CAS patients had similar stroke rates (5.3% CAS versus 4.1% CEA; P=0.12) but higher all-cause mortality rates (9.9% CAS versus 6.1% CEA; P<0.001). Using Cox multivariable models, there was a similar stroke risk (hazard ratio, 1.28; 95% CI, 0.90-1.79) but CAS patients had a significantly higher mortality (HR, 1.32; 95% CI, 1.02-1.71). Sensitivity analyses suggested that unmeasured confounders could be responsible for the mortality difference. In multivariable analysis, stroke risk was highest in the patients symptomatic at the time of revascularization. CAS patients had a similar stroke risk but an increased mortality rate at 1 year compared with CEA patients, possibly related to the higher baseline risk profile in the CAS patient group.