Original Paper Cerebrovasc Dis 1998;8:210–213 Is Another Clinical Trial Warranted Regarding Endarterectomy for Asymptomatic Carotid Stenosis? Seemant Chaturvedi a Alison Halliday b a Department of Neurology, Wayne State University/Detroit Medical Center, Detroit, Mich., USA, and b Department of Surgery, St. Mary’s Hospital, London, UK OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Key Words Carotid endarterectomy Carotid stenosis Cerebral infarction OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO Abstract Background: Several clinical trials regarding carotid endarterectomy for asymptomatic stenosis have been conducted in the past two decades. These research studies have not resolved the controversy regarding the optimal treat- ment of patients with this condition. Summary of review: We examine some of the reasons why there is persisting uncertainty regarding the value of carotid endarterectomy for asymptomatic stenosis. These include the sample size of earlier studies, the generalizability of these studies, and the clinical impor- tance of the reported surgical benefits in some studies. We then review the rationale for another, larger clinical trial. Conclusions: The role of endarter- ectomy for asymptomatic stenosis remains an unsettled issue. A larger clinical trial may shed light on how to best identify which patients derive clinically significant benefits from prophylactic carotid artery surgery. OOOOOOOOOOOOOOOOOOOOOO Received: September 8, 1997 Accepted: January 23, 1998 Seemant Chaturvedi, MD Department of Neurology, Wayne State University 6E-UHC, 4201 St. Antoine Detroit, MI 48201 (USA) Tel. +1 313 577 1244, Fax +1 313 577 4641, E-Mail Schaturv@med.wayne.edu ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 1998 S. Karger AG, Basel 1015–9770/98/0084–0210$15.00/0 This article is also accessible online at: http://BioMedNet.com/karger In 1995, the results of the Asymptomatic Carotid Ath- erosclerosis Study (ACAS) were published [1]. Prior to the actual publication, there were front page stories in major newspapers and a clinical alert was released by the Na- tional Institutes of Health. Since the medical and surgical communities have had time to digest the results, there appears to be a lingering controversy as to the appropriate role, if any, for carotid endarterectomy (CE) in the asymptomatic patient. Some prominent stroke neurologists and the Canadian Stroke Consortium have advocated not performing CE for asymptomatic stenosis [2–5], whereas some surgical groups have advocated taking CE one step further by screening asymptomatic individuals [6]. In this article, we would like to address some of the concerns which have been raised regarding the ACAS. We shall then explore whether another clinical trial regarding CE for asymptomatic stenosis is warranted. Concerns Regarding ACAS We have no doubt that the ACAS was scrupulously conducted and that the results are valid. Most neurolo- gists and surgeons involved in the study were experienced clinical investigators and many were also participating in other major stroke clinical trials such as the North Ameri- can Symptomatic Carotid Endarterectomy Trial (NAS- CET). The major points which we would like to discuss are the following: sample size, subgroup analysis, generali- zability, whether statistical benefit is equivalent to clini- cal benefit, and identifying appropriate asymptomatic patients for CE. With regard to sample size, at the time of publication of the study results, the ACAS was the largest clinical trial ever conducted regarding CE for asymptomatic stenosis. With 1,662 patients, it enrolled approximately four times as many patients as the earlier VA Cooperative Study [7]. Downloaded by: Leiden University 132.229.14.7 - 8/27/2014 3:18:19 PM