Correspondence
Endarterectomy versus Stenting for Carotid Stenosis
N Engl J Med 2007; 356:305-307January 18, 2007
- Article
To the Editor:
Mas et al. (Oct. 19 issue)1 report the results of the randomized Endarterectomy versus Angioplasty in Patients with Symptomatic Severe Carotid Stenosis (EVA-3S) trial, which suggest the superiority of carotid endarterectomy over carotid-artery stenting in patients with symptomatic stenosis of at least 60%. The results are similar to the recently reported findings in the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE) study.2 However, some points deserve comment. First, the most active center in the trial included few patients (approximately 10 per year). Second, in an important proportion of cases (5%), carotid-artery stenting failed and endarterctomy had to be performed. Third, only distal filters were used as embolic protection devices; no proximal-flow blockage systems were used.3,4 Fourth, the median carotid-artery stenting time was quite long (70 minutes), suggesting that the patients' anatomy was complex or that the technical skills of the operators were still in the learning curve.5 Thus, the main message of the EVA-3S trial might be that carotid-artery stenting remains a complex procedure that should be performed in high-volume, specialized centers, where tailored carotid-artery stenting procedures are performed according to the specific characteristics of the patient and lesion.
5 ReferencesRobert F. Bonvini, M.D.
Marc Righini, M.D.
Hôpitaux Universitaires de Genève, 1211 Geneva, Switzerland
robert.bonvini@hcuge. ch 1
Mas J-L ,Chatellier G ,Beyssen B , et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med 2006;355:1660-1671
Full Text | Web of Science | Medline2
SPACE Collaborative Group
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Reimers B ,Sievert H ,Schuler GC , et al. Proximal endovascular flow blockage for cerebral protection during carotid artery stenting: results from a prospective multicenter registry. J Endovasc Ther 2005;12:156-165
CrossRef | Web of Science | Medline4
Cremonesi A ,Manetti R ,Setacci F ,Setacci C ,Castriota F . Protected carotid stenting: clinical advantages and complications of embolic protection devices in 442 consecutive patients. Stroke 2003;34:1936-1941
CrossRef | Web of Science | Medline5
Lin PH ,Bush RL ,Peden EK , et al. Carotid artery stenting with neuroprotection: assessing the learning curve and treatment outcome. Am J Surg 2005;190:850-857
CrossRef | Web of Science | Medline
To the Editor:
The report on the EVA-3S trial raises substantial concerns about complications of carotid-artery stenting. Contributing factors may have included the minimal experience in carotid-artery stenting of some operators (possibly zero, requiring supervision, according to the protocol), with a low average number of patients enrolled (1.8 per center per year in the stenting group) during the 5 years that it took to enroll 527 patients in 30 centers. It would be important to know how many carotid revascularization procedures each center performed during the same period. (Was there a screening log?) In addition, the pharmacologic environment of the stenting procedures was not well controlled. Dual antiplatelet agents were not used in 17.1% of patients before stenting and, surprisingly, were not used in 14.6% of patients after stenting. Heparin was not given during the procedure in 2.4% of patients, although it is not clear whether they received an alternative antithrombotic agent. The required technical skills and adjunct pharmacologic considerations for carotid-artery stenting1-4 offer substantial room for improvement in future trials in this field.
4 ReferencesMartial Hamon, M.D.
John W. Riddell, M.D.
Centre Hospitalier Universitaire Caen, 14033 Caen, France
hamon-m@chu-caen.fr 1
Bhatt DL ,Kapadia SR ,Bajzer CT , et al. Dual antiplatelet therapy with clopidogrel and aspirin after carotid artery stenting. J Invasive Cardiol 2001;13:767-771
Medline2
Chaturvedi S ,Yadav JS . The role of antiplatelet therapy in carotid stenting for ischemic stroke prevention. Stroke 2006;37:1572-1577
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Dalainas I ,Nano G ,Bianchi P ,Stegher S ,Malacrida G ,Tealdi DG . Dual antiplatelet regime versus acetyl-acetic acid for carotid artery stenting. Cardiovasc Intervent Radiol 2006;29:519-521
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Buhk JH ,Wellmer A ,Knauth M . Late in-stent thrombosis following carotid angioplasty and stenting. Neurology 2006;66:1594-1596
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To the Editor:
Deficient methods and lack of experience on the part of the endovascular operator may have undermined the results of the EVA-3S study. We would argue, however, that it provides invaluable lessons. A good procedure is one that can be performed safely by all appropriately trained practitioners. The results of the EVA-3S trial underscore the need to standardize the training and performance of operators of carotid-artery stenting.
The failure to mandate routine use of embolic protection and combined antiplatelet therapy directly contradicts current standards of care.1,2 The suggestion that the use of embolic protection devices may cause adverse events implies that the study included patients with suboptimal anatomy. This lack of proper patient selection is likely to have contributed to the unacceptably high event rate. Furthermore, the enrollment of patients regardless of angiographic appearance diverges from currently accepted carotid-stenting methods.
We think that the safety and efficacy of carotid stenting will be proved in appropriately selected patients. To accomplish this, available recommendations regarding clinical competence must be adopted.3,4 The routine use of embolic protection and appropriate periprocedural antiplatelet therapy is essential. Finally, understanding what constitutes appropriate patient selection is fundamental to the success of this procedure.
Andrew O. Maree, M.D.
Kenneth A. Rosenfield, M.D.
Massachusetts General Hospital, Boston, MA 02114Dr. Maree reports receiving research funds from Accumetrics, Boehringer Ingelheim, the Medicines Company, and Abbott. Dr. Rosenfield reports receiving consulting fees from and serving as a member of speakers' bureaus for Abbott, Bard, Cordis, Boston Scientific, Medtronic, ev3, Bristol-Myers Squibb, Schering-Plough, and Genzyme; receiving research support from Accumetrics, Abbott, Bard, Cordis, Boston Scientific, Medtronic, ev3, and the Medicines Company; and holding shares in Medical Simulation.
4 References1
Kastrup A ,Groschel K ,Krapf H ,Brehm BR ,Dichgans J ,Schulz JB . Early outcome of carotid angioplasty and stenting with and without cerebral protection devices: a systematic review of the literature. Stroke 2003;34:813-819
CrossRef | Web of Science | Medline2
Markus HS ,Droste DW ,Kaps M , et al. Dual antiplatelet therapy with clopidogrel and aspirin in symptomatic carotid stenosis evaluated using doppler embolic signal detection: the Clopidogrel and Aspirin for Reduction of Emboli in Symptomatic Carotid Stenosis (CARESS) trial. Circulation 2005;111:2233-2240
CrossRef | Web of Science | Medline3
Rosenfield K ,Babb JD ,Cates CU , et al. Clinical competence statement on carotid stenting: training and credentialing for carotid stenting -- multispecialty consensus recommendations: a report of the SCAI/SVMB/SVS Writing Committee to develop a clinical competence statement on carotid interventions. J Am Coll Cardiol 2005;45:165-174
CrossRef | Web of Science | Medline4
Creager MA ,Goldstone J ,Hirshfeld JW Jr , et al. ACC/ACP/SCAI/SVMB/SVS clinical competence statement on vascular medicine and catheter-based peripheral vascular interventions: a report of the American College of Cardiology/American Heart Association/American College of Physician Task Force on Clinical Competence (ACC/ACP/SCAI/SVMB/SVS Writing Committee to develop a clinical competence statement on peripheral vascular disease). J Am Coll Cardiol 2004;44:941-957
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Author/Editor Response
Operator experience was not a major determinant of the 30-day risk of stroke or death in the EVA-3S trial. Among the patients in the stenting group, 15.8% were treated by interventional physicians who had performed more than 50 carotid-stenting procedures, 45.4% by physicians who had performed 50 or fewer procedures, and 38.8% by physicians still in procedural training. The 30-day risk of stroke or death for these three groups was 12.2%, 11.0%, and 7.1%, respectively (P=0.49). In addition, although the required level of operator experience was lower in the EVA-3S study than in the SPACE study,1 the complication rates were similar: 9.6% in the EVA-3S study and 7.7% in the SPACE study for the 30-day risk of stroke or death and 3.4% and 4.8%, respectively, for the 30-day risk of disabling stroke or death. High hospital or physician volume has been associated with better outcomes across a wide range of procedures, but the relationship is weak for carotid endarterectomy2 and is still unknown for carotid stenting. These findings suggest a potential role of other risk factors related to the patient (e.g., the presence of severe aortic-arch atheroma and plaque morphology) or to the procedure itself.
Patient selection may be a key issue for the success of carotid stenting. However, the factors associated with the risk of complications after carotid stenting have yet to be identified. With regard to the procedure, no study has convincingly established the superiority of stenting with cerebral protection over unprotected stenting or the superiority of a particular type of stent or cerebral-protection device. The optimal periprocedural medical treatment also remains to be established. In the EVA-3S trial, only 20 of the 247 patients in whom stenting was completed underwent unprotected stenting. After excluding these patients, the 30-day risk of stroke or death in the stenting group was 7.9%, as compared with 3.9% in the endarterectomy group (relative risk, 2.0; 95% confidence interval, 1.0 to 4.4). In the stenting group, the 30-day risk of stroke or death among the 36 patients who received single antiplatelet therapy after the procedure did not differ significantly from that of patients who received dual antiplatelet therapy.
The results of the EVA-3S trial underscore the need to improve the safety of endovascular treatment before it can become an alternative to carotid endarterectomy in patients with symptomatic carotid stenosis. A large number of patients will be needed to identify which factors related to patient characteristics, operator experience, and the procedure itself are associated with a high risk of stroke after carotid stenting. In this respect, the principal investigators of the European stenting trials have agreed to perform a meta-analysis of combined data from individual patients.3
3 ReferencesJean-Louis Mas, M.D.
Hôpital Sainte-Anne, 75014 Paris, France
jl.mas@ch-sainte-anne. fr Gilles Chatellier, M.D.
Hôpital Européen Georges Pompidou, 75015 Paris, Francefor the EVA-3S Investigators
1
SPACE Collaborative Group
CrossRef | Web of Science | Medline2
Halm EA ,Lee C ,Chassin MR . Is volume related to outcome in health care? A systematic review and methodologic critique of the literature. Ann Intern Med 2002;137:511-520
Web of Science | Medline3
Hacke W ,Brown MM ,Mas JL . Carotid endarterectomy versus stenting: an international perspective. Stroke 2006;37:344-344
CrossRef | Web of Science | Medline
- Citing Articles (2)
Citing Articles
1
J. U. Harrer, R. Morschel, M. Mull, C. M. Kosinski. (2008) High rate of restenosis after carotid artery stenting in patients with high-grade internal carotid artery stenosis. Journal of Neurology 255:9, 1309-1314
CrossRef2
I. Van Herzeele, R. Aggarwal, S. Neequaye, M. Hamady, T. Cleveland, A. Darzi, N. Cheshire, P. Gaines. (2008) Experienced Endovascular Interventionalists Objectively Improve their Skills by Attending Carotid Artery Stent Training Courses. European Journal of Vascular and Endovascular Surgery 35:5, 541-550
CrossRef
