Carotid Endarterectomy Versus Stenting: An International Perspective
To the Editor:
With interest we read the comment of Hobson et al entitled “Carotid Artery Stenting and the Recruitment Challenges in a clinical trial.”1
Although we completely share the concerns of the authors regarding slow recruitment into the CREST Trial, constantly growing use of carotid stenting in symptomatic patients outside of protocols, and the lack of evidence in this area, we cannot agree with the perception that it is mostly up to CREST to solve the problems.
The authors mention shortly that larger clinical trials “are currently underway in North America and Europe.” With reference 10 they cite the CAVATAS trial that finished recruitment long ago. They state that “recruitment into these trials will also be slow and the data may not be available for the next 2 to 3 years.”
As the principal investigators of 3 European Trials, we would like to update the organizers of CREST and the readers of Stroke in the field of what’s going on in the randomized symptomatic carotid endarterectomy versus stenting trials outside of North America.
The early results of CAVATAS were published 3 years ago and the results of long-term follow-up were presented at this year’s European Stroke Conference and will be submitted for publication soon.
The next on-going trial is the International Carotid Stenting Study (ICSS), the follow-up to the CAVATAS trial. This trial includes North American centers in Canada as well as several European countries and Australia, and its study protocol has been recently published.2 Almost 600 patients are already included in this trial.
The second trial, which is also not cited in this article, is the French EVA 3S Trial. Its trial design and protocol amendment has also recently been published.3,4 Almost 500 patients are already included in this trial.
The third one is the SPACE Trial. The trial protocol of SPACE has also been published.5,6 It is not adequately referenced by mentioning a poster at the ASA Meeting 2 years ago. This trial is probably the most advanced trial, and termination of recruitment is expected in the next couple of months. Therefore, it will not take 3 years until data from this German-Austrian Trial are available.
By the way, it should be mentioned that the 3 European Trials have already agreed to perform a joint data analysis after completion and publication of all 3 trials.7 We hope we will also be able to include results from CREST in this meta-analysis.
We wish our American colleagues a lot of success in improving the recruitment rates. We need much more data from all the trials before it will be clear which treatment is optimal for symptomatic carotid stenosis.
Hobson RW II, Brott TG, Roubin GS, Silver FL, Barnett HJM. Carotid Artery Stenting Meeting the Recruitment Challenge of a Clinical Trial. Stroke. 2005; 36: 314–315.
EVA-3S Investigators. Carotid Angioplasty and Stenting With and Without Cerebral Protection: Clinical Alert From the Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis (EVA-3S) Trial. Stroke. 2004; 35: 18–20.
Ringleb P, Kunze A, Allenberg J, Hennerici M, Jansen O, Maurer P, Zeumer H, Hacke W. Evaluation der stentgeschützten Angioplastie zur Therapie von symptomatischen Stenosen der A. carotis. SPACE und andere randomisierte Studien Nervenarzt. 2003; 74: 482–489.
We wish to thank the authors for their response to our recently published commentary on carotid artery stenting (CAS).1 Our intent was to stimulate clinicians in the United States and Canada to become more involved in the NINDS, NIH-sponsored CREST (Carotid Revascularization Endarterectomy versus Stenting) protocol. Although recruitment to CREST was described as slow, we are pleased to announce that randomization continues to accelerate following publication of the commentary and now exceeds 600 participants at our over 100 clinical sites.
We have great admiration for our European colleagues and their accomplishments in the field of CAS and will welcome the early publication of data from the SPACE Trial. Our brief commentary was not designed as a comprehensive review. Nonetheless, we regret the impression or the inadvertent failure to acknowledge all currently active trials.
We welcome the opportunity to agree with the authors that expanded use of CAS outside organized randomized clinical trials threatens rigorous study of potential alternatives to carotid endarterectomy. As noted in our commentary, “If we fail to achieve a study of adequate size, we will not produce convincing evidence of the value of carotid stenting in stroke prevention.” We also agree that ultimate joint analyses of the trial results will be desirable. Dr Hobson corresponded previously with Professor Brown recommending such an effort and expressing our willingness to cooperate in these activities.
The CREST investigators applaud the performance of clinical trials in North America and Europe to clarify the role of carotid endarterectomy and stenting in the management of extracranial carotid occlusive disease. We have no disagreement with our European colleagues on this crucial point.