Carotid Stenting: Where Science & Policy Diverge

 
 
 
 - Christopher J. White, MD, FSCAI
Christopher J. White, MD, FSCAI
 

A 68-year-old gentleman was recently referred to me by his cardiologist, who had heard a carotid bruit on a routine exam. The patient told me that he did not want to have carotid surgery because his older brother, who had undergone surgery, suffered vocal cord paralysis and still could not speak correctly. A carotid duplex study demonstrated a critical stenosis greater than 80 percent, and angiography confirmed the severity of the lesion and favorable anatomy for stent placement.

After reviewing the patient’s data, I informed him he was a candidate for a carotid stent but that Medicare would not pay for his procedure. Medicare would pay for him to have surgery, but unless he was willing to pay up to $20,000 out of pocket, he could not have a stent. My patient was surprised. His cardiologist had reassured him that he would be able to avoid surgery. He asked me why Medicare would not allow him to have choice of revascularization procedures if he and his doctor thought carotid stenting was a reasonable treatment option.

My patient did not qualify for Centers for Medicare & Medicaid Services (CMS)-approved carotid stent therapy because the only pathway open to him was participation in a clinical trial and ACT-1, the last remaining clinical trial for asymptomatic patients, had closed the week before. The company sponsoring ACT-1 already has an FDA-approved carotid stent system but at this point it has little hope that CMS will ever cover asymptomatic patients at risk for stroke with carotid artery stenting, even though carotid stenting has been shown to be equally safe and effective as surgery and is much less invasive than surgery.

When ACT-1 closed, average surgical-risk asymptomatic patients with carotid artery disease, including mine, lost their last hope of avoiding surgery despite the results of CREST (N Engl J Med 2010;363[1]:11-23), the largest ever randomized carotid stent trial, completed three years ago. CREST found no difference between carotid stenting and carotid endarterectomy after four years of follow-up. CMS has refused every request to cover stents for these patients, despite the opinions of multiple professional specialty societies, including cardiologists, surgeons, radiologists and neurologists, who in 2011 endorsed the choice of stents vs. surgery as a reasonable option for average surgery-risk patients (Stroke 2011;42[1]:227-76; Stroke 2011;42:e420-463). And now, with the closure of ACT-1, physicians have lost our only means to offer a choice of carotid stent therapy to asymptomatic patients despite FDA approval of seven different carotid stent systems found to be “safe and effective.” There are no exceptions, even for patients for whom stenting would clearly be the best option.

Why will CMS cover carotid surgery in low-risk asymptomatic patients but not cover carotid stenting in those same patients, even though the data demonstrate “equipoise”? Although I have been actively involved in efforts to persuade CMS and have personally spoken with CMS officials countless times, I must admit I still don’t know why my patients are being denied the choice of less invasive therapy, stenting rather than surgery, to prevent a stroke.

On the crest of a clinical option

The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) was designed to compare carotid-artery stenting with carotid endarterectomy in patients with symptomatic or asymptomatic extracranial carotid stenosis (N Engl J Med 2010;363[1]:11-23). The randomized, controlled clinical trial enrolled 2,502 patients with symptomatic or asymptomatic carotid stenosis to undergo carotid-artery stenting or carotid endarterectomy. The composite endpoint was stroke, MI or death from any cause during the periprocedural period or any ipsilateral stroke within four years after randomization.

Key findings included:

  • No difference between the groups in the primary endpoint based on symptomatic status or sex;
  • At four years, the rate of stroke or death was 6.4 percent in the carotid-artery stenting group vs. 4.7 percent in the endarterectomy group;
  • In symptomatic patients, the rates were 8 percent vs. 6.4 percent;
  • In asymptomatic patients, the rates were 4.5 percent vs. 2.7 percent;
  • The periprocedural risk was higher in the stenting group for stroke (4.1 percent vs. 2.3 percent) but lower for MI (1.1 percent vs. 2.3 percent); and
  • Ipsilateral stroke rates were 2 percent vs. 2.4 percent.
  • "The differential results for myocardial infarction and stroke offer