Cath Lab Digest

Q:What do you anticipate the CREST results will show?

Rosenfield: CREST (Carotid Revascularization Endarterectomy versus Stent Trial) is a landmark trial which shows that endarterectomy and stenting for carotid artery stenosis appear to be comparable based on the primary endpoint of the trial: death, stroke and myocardial infarction. Both carotid artery stenting (CAS) and carotid endarterectomy (CEA) had remarkably low event rates and were shown to be very safe and effective stroke prevention therapies. It should be noted that this is the largest (2,522 subjects, 225 operators, 122 sites in the U.S. and Canada), most rigorous prospective, randomized trial to be carried out for these therapies and represents level-A evidence. The fact that the results are comparable for both of these therapies and that the safety and efficacy for both are very high is great news for patients. Moving forward, patients will have a choice in modalities to reduce stroke, and physicians and patients will be able to decide which therapy is best at an individual level.

It is very reassuring to know that these therapies, which have been discussed and applied for years, are just as effective as we thought they were — perhaps even more so. The CREST results demonstrate the best outcomes of any trial to date for this type of broad-based application involving such a large number of patients and investigators. The fact that the trial was able to show such favorable results across this broad spectrum is quite remarkable. Thus, CAS will be better for some patients and CEA for others. We still need to analyze the data and the various factors that would determine which therapy is better for patients at both ends of the spectrum. CREST shows us that the largest group of patients — those in the middle of the spectrum — will be suitable candidates for either therapy, and it will be up to them and their physicians to decide which to undergo. Keep in mind that this study involved a whole new cadre of patients: those in the standard-risk category (symptomatic and asymptomatic), and not surgical high-risk patients, who have been evaluated in previous studies.

CREST showed some minor differences in results based on age, with the very elderly patients (> 80 years of age) having better outcomes with endarterectomy, while younger patients (< 70 years of age) had better outcomes with stenting. However, the overall event rates were quite low, and the incidence of death was extremely low.

Q: How long will these patients be followed?

Rosenfield: The primary endpoint was a composite of periprocedural death, stroke, and myocardial infarction out to several weeks, and the incidence of ipsilateral stroke out to as long as 4 years (median of 2.5 years). The lead investigator, Dr. Thomas Brott, has recently obtained tentative approval for his center to follow these patients out to as long as 10 years, which will be an important addition to this trial and will provide valuable long-term information about these patients. The Kaplan-Meier curve shows that for both CAS and CEA, a large majority of the events occurred early on.

Q: What about CMS coverage for these procedures? Will the CREST results change their decision about carotid stenting?

Rosenfield: These standard-risk patients are not currently covered by the CMS (Centers for Medicare and Medicaid Services). I think that the CREST trial provides the impetus for the CMS to move forward with approval of stenting for standard-risk patients. The outcomes speak for themselves in terms of both acute and long-term benefits for patients and should result in the CMS looking favorably upon CAS so that patients can have the choice. It should also be noted that both CAS and CEA fall very well within the AHA (American Heart Association) guidelines for appropriate, effective and safe therapies. This is important because it demonstrates that in a broad-based trial involving such a large number of patients, sites and investigators, the results should be generalizable to the population as a whole. In my view, it would only be appropriate for the CMS to act on this information.

Q: Were proximal and/or distal protection devices used in the stenting arm of this trial?

Rosenfield: The stent and distal protection devices were identified at the outset of the CREST trial: the RX Acculink™ carotid stent (Abbott Vascular, Abbott Park, Illinois) and the RX Accunet™ embolic distal protection device (Abbott Vascular) were utilized throughout the trial. The first 4–5% of CAS patients in CREST, however, did not have distal protection devices used, and the trial was temporarily put on hold while this device was entering the market. Of course, over time, techniques and devices have evolved, and the new devices have been introduced to the market. What is exciting about this trial is that it provides the impetus to see how we can even further improve upon these results, given the newer technologies now available.

Q: Has CEA evolved in terms of technique since the launch of CREST?