Ambulatory Carotid Stenting in Patients With Asymptomatic Carotid Artery Stenosis
To the Editor:
In a recent article by Al-Mubarak et al,1 the authors claim to have demonstrated the feasibility and safety of performing carotid angioplasty and stenting (CAS) as an ambulatory outpatient procedure. In our opinion, both the title of the article and the conclusion drawn by the authors are misleading and cannot be supported by the presented data.
Over a 2-year period, 341 carotid stenting procedures in 300 patients with extracranial carotid artery stenosis were performed at the authors’ institution. They now report the results of a subgroup of these patients, consisting of those 92 patients (31%) who had successful CAS without complications, had a successful vascular access site hemostasis, were judged to be compliant, and had adequate care at home. On the basis of these 4 criteria, a same-day discharge was judged to be appropriate for all 92 patients of this subgroup, whereas hospitalization was required for the remaining 208 patients. No strokes, deaths, repeated procedures, or relevant access site complications occurred in the first group. However, no further information on the outcome of the latter is given.
As for the title of the article, the given data do not seem to provide any information on the true procedural safety of ambulatory CAS, since the absence of any early complication was the main inclusion criterion for the population described in the article. Moreover, it is not the short-term outcome after prospectively planned ambulatory CAS that is reported, but rather the outcome of a distinct subgroup of patients for whom an early discharge after CAS was judged feasible hours after the procedure was done. Thus, the reported data do not help to estimate the safety and risk of the procedure, nor can the true feasibility of CAS in an ambulatory setting be assessed.
By the therefore unjustified conclusion, that CAS can safely be performed even in an ambulatory setting, the general safety of the procedure in patients with extracranial carotid stenosis is implied. However, the data presented in the article are not sufficient to assess the periprocedural risk of CAS, nor do they add any new information regarding its still unproven efficacy in preventing stroke in patients with extracranial carotid stenosis compared with carotid endarterectomy (CEA). The conclusions that can be drawn from the reported data merely are that approximately 30% of patients might be safely discharged a few hours after CAS if the predefined criteria are applied and that the thereby selected subgroup seems to have a good short-term outcome.
In our opinion, the high rate (72%) of patients with asymptomatic carotid artery stenosis who were treated in this series is of particular concern. Although the authors present an impressive safety record with no neurological events or deaths occurring after 1 year, it is very unlikely that these results can be transferred to the current clinical practice. Since an asymptomatic carotid artery stenosis is associated with a comparatively low risk of stroke of only about 2% per annum,2 a very low periprocedural risk is a crucial precondition for the long-term efficacy of any invasive therapy for stroke prevention. Unfortunately, as mentioned above, the current article does not present the actual rates of periprocedural complications for the complete population of 300 patients. Yet, a 30-day stroke and death rate of 7.4% is reported in another series from the same institution published in 2001, with symptomatic and asymptomatic patients having similar 30-day outcomes (8.2% versus 6.3%, respectively; P=0.47).3 In the International Stent Registry, Wholey et al4 reported a combined all-strokes-and-death rate of 3.4% within 30 days following CAS in 1361 asymptomatic patients. These numbers clearly exceed the complication rate of less than 3.0%, which is recommended by the American Heart Association as the upper limit for CEA in asymptomatic patients.5 Moreover, these data were collected in uncontrolled and mostly retrospective series, and even higher complication rates may be expected in a prospective controlled study in which neurologists take part in the follow-up investigations.
In addition, there are still no controlled data available that demonstrate any benefit of CAS in previously asymptomatic patients. The only completed randomized trial comparing CEA and CAS included mainly symptomatic patients (98%) and showed similar major risks and effectiveness for both procedures.6 However, the study yielded periprocedural stroke and death rates of about 10% in each group, which are considerably higher than those of previous large CEA trials in symptomatic patients on which treatment recommendations are based. A similar risk increase for CAS and CEA in asymptomatic patients would be devastating, leaving not the slightest chance of any benefit from both procedures. Since these results are likely representative of clinical practice, the benefit of both ambulatory and in-hospital CAS and of CEA for asymptomatic patients is at least questionable.
Until scientifically validated data from randomized trials demonstrate a lasting benefit of CAS in asymptomatic patients, a widespread use of either ambulatory or in-hospital carotid stenting should not be encouraged. Meanwhile, CAS should be restricted to experienced centers and to randomized patients in controlled trials.
- ↵Al-Mubarak N, Roubin GS, Vitek JJ, New G, Iyer SS. Procedural safety and short-term outcome of ambulatory carotid stenting. Stroke. 2001; 32: 2305–2309.
- ↵Roubin GS, New G, Iyer SS, Vitek JJ, Al-Mubarak N, Liu MW, Yadav J, Gomez C, Kuntz RE. Immediate and late clinical outcomes of carotid artery stenting in patients with symptomatic and asymptomatic carotid artery stenosis: a 5-year prospective analysis. Circulation. 2001; 103: 532–537.
- ↵Biller J, Feinberg WM, Castaldo JE, Whittemore AD, Harbaugh RE, Dempsey RJ, Caplan LR, Kresowik TF, Matchar DB, Toole JF, Easton JD, Adams HP, Brass LM, Hobson RW, Brott TG, Sternau L. Guidelines for carotid endarterectomy. Circulation. 1998; 97: 501–509.