To the Editor:
Regarding the article by Krajcer1 on carotid artery stenting (CAS), I wish to provide a counter-argument in support of the decision of the Centers for Medicare & Medicaid Services (CMS) to limit CAS to symptomatic patients who are not candidates for surgical endarterectomy. There are several important issues to emphasize. The most important is that too many carotid endarterectomies are being performed for asymptomatic, moderate stenosis (<80%).
Despite our being surgeons who jumped on the endarterectomy bandwagon in a big way after the report of the asymptomatic carotid artery study (ACAS),2,3 my associates and I have basically abandoned “prophylactic” endarterectomy for asymptomatic, < 80% carotid stenosis. We know that many surgeons have not. But we were dismayed by operating on the thin, nonthreatening plaques found in patients with 60% to 80% stenosis, and that caused us to re-evaluate the data from the ACAS trial. We subsequently gathered that an 11% to 5% reduction in stroke and mortality meant that we had to operate on 20 patients in order to prevent 1 stroke. To put it another way—and this is the explanation we give to our patients, particularly the elderly ones—if you have an asymptomatic 60% to 80% stenosis, your 3-year chance of not having a stroke is in excess of 90%, as opposed to your undergoing endarterectomy, wherein your 3-year chance of not having a stroke is 95%. Upon hearing these numbers—not the 50% risk reduction touted by the ACAS investigators—almost all of our patients elect to have medical therapy and careful follow-up.
Where is the argument for limiting CAS, you ask? If a surgeon can admit that too many endarterectomies are done by people who have not examined their own practice or critically appraised the ACAS study, cardiologists should pause to consider whether the less invasive CAS procedure, left unchecked, might be too tantalizing to sell to asymptomatic patients at this stage of our knowledge. If the CMS were to pay for CAS done for asymptomatic 60% to 80% stenosis, the volume of these marginally indicated procedures would mushroom, as would the financial cost to the health care system.
We can't put the genie back in the bottle for asymptomatic carotid endarterectomy, but fortunately the genie has not been let out for CAS. I believe that CMS is wise to limit CAS until there are more definitive data that demonstrate the efficacy of carotid stenting, particularly in ACAS-type asymptomatic patients with moderate stenosis. I am not generally in favor of government control of medicine, but I believe the decision to limit CAS at present is the right choice. It is not, after all, an irreversible decision.
C. Steven Powell, MD, FACS
Professor of Surgery, Department of Surgery, Brody School of Medicine, Greenville, North Carolina
References
- 1.Krajcer Z. Carotid stenting. Tex Heart Inst J 2005;32:369–71. [PMC free article] [PubMed]
- 2.Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. N Engl J Med 1991;325:445–53. [DOI] [PubMed]
- 3.Endarterectomy for asymptomatic carotid artery stenosis. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. JAMA 1995;273:1421–8. [PubMed]