Current Developments With Carotid Stenting (CAS): The Perfect Vascular Storm Re-Visited

CAS developments were portrayed as “The Perfect Vascular Storm” in the second issue of VDM (December 2004). These were the days before VDM had decided to adopt a new format and become a peer-review journal. In that article, I described and opined on the current state of affairs with “the hottest vascular topic of the day, carotid stenting.” Unequivocally, it continues to be the case! But things have evolved in the short few months since its publication and significant additional developments have taken place. Powerful among these was CMS’s reimbursement decision, announced March 17, 2005. Given the enormous and ever-growing interest in carotid revascularization, it seemed appropriate to dedicate this Editor’s Corner to the same CAS topic, providing an up-to-date report on where we stand today (May ’05).

• Regulatory Approval: FDA approval of the first CAS system (by Guidant) was announced on August 31, 2004. The agency’s decision was based on the results of the Archer clinical trial, and followed on the heels of the Advisory Panel’s favorable decision on the SAPPHIRE trial of April ’05. The FDA decision — related, as usual, to safety and efficacy — supported clinical application of CAS for carotid revascularization on symptomatic (>50% stenosis) and asymptomatic (>80%) lesions occurring on patients deemed to be high-risk candidates for CEA because of anatomical factors or severe medical co-morbidities. Approvals of several additional CAS systems (Cordis Endovascular, Abbott Vascular and Boston Scientific) are anticipated later this year (2005).

• CMS followed suit on March 17, 2005. However, their decision did not mirror the FDA approval, as they excluded asymptomatic patients. Only patients with symptomatic >70% carotid stenoses, at high risk for CEA (“in the opinion of a surgeon”) will be covered by Medicare under this decision. In this context, it is important to remember that CMS’ charter is different from the FDA’s. CMS’ focus is on whether a procedure (and/or device) is “reasonable and necessary” — as opposed to FDA’s “safety and efficacy.” Predictably, these decisions by the federal agencies have stimulated a great deal of debate, if not controversy — the CMS decision in particular. The reasons for the latter are likely multiple and complex. I tend to see it as an almost “natural” product of the current state of affairs with carotid intervention and — frankly — did not find their decision surprising. What would you do in CMS’ shoes when faced with significant division and (even) outright disagreement in the medical community in regards to the treatment of asymptomatic patients? There are also the acknowledged challenges related to adequate monitoring of appropriate indications and the results of CAS in hospitals across the U.S., not to mention the unresolved issues of training and credentialing hundreds, if not thousands, of new carotid interventionists…! While industry and a few others are expressing profound disappointment with CMS’ decision as it has — truly — put the brakes on widespread clinical use of CAS anytime soon, I for one regard this as a largely positive development which, in due time, will prove beneficial to all stakeholders in the CAS field. There is something to be said for the gradual and “controlled” roll-out of this exciting new therapy. Most importantly, it will give us all the opportunity to sort out some of the very thorny issues related to CAS training and credentialing, allowing for measured, thoughtful discussions without feeling the pressure of having to “jump on the CAS band-wagon” right away. The next crucial developments in terms of data acquisition and validation will target the low-risk and asymptomatic carotid patient population. Most likely, manufacturers aspiring to obtain a more open-ended label for their carotid stenting equipment will feel compelled to design and conduct clinical trials that will (hopefully) validate the CAS procedure in the treatment of carotid stenosis and stroke prevention for the majority of patients. In the end, I remain of the opinion that carotid stenting will ultimately triumph and become the predominant form of carotid revascularization in the years to come. The transformational process (in the U.S.), however, is clearly going to be significantly slower and lengthier than first envisioned.

Correspondence: frank.criado@medstar.net