BY AMERICAN HEART ASSOCIATION NEWS
LOS ANGELES — The gold standard of surgical stroke prevention – a procedure that involves making an incision in the neck and dates to the 1950s – may finally be getting some competition. Because new research shows that a far less invasive approach that opens neck arteries with a stent is just as safe and effective, according to the largest and longest comparison of the two procedures ever done.
Experts say the new findings could prompt Medicare and other insurance providers to start covering the procedure for more patients.
The carotid arteries – the main vessels on each side of the neck that supply blood to the brain – can become blocked by plaque, possibly causing a stroke. Of the more than 690,000 Americans who suffer a clot-caused, or ischemic, stroke each year, one-fifth are caused by carotid artery disease.
The surgery, called carotid endarterectomy, involves getting to the carotid artery through an incision in the neck and cleaning out the plaque. It has long been the preferred treatment for carotid artery disease. But the less invasive stenting approach has been approved by the Food and Drug Administration for patients at risk for stroke, sparking a debate over which treatment is best.
In the Carotid Revascularization Endarterectomy versus Stenting Trial, or CREST, researchers compared surgery to carotid artery stenting, in which doctors thread a wire mesh tube through a major artery into the narrowed neck artery to prop it open.
Results reported Thursday at the American Heart Association’s International Stroke Conference show the two procedures performed equally well in lowering the risk of strokes among 2,502 U.S. and Canadian patients who were 69 years old on average at the start of the study. After up to a decade of follow-up, 6.9 percent of patients who received a stent and 5.6 percent of patients who underwent surgery had a stroke.
“That’s very low over a long time,” said neurologist Thomas Brott, M.D., the study’s lead investigator and a professor of neurosciences at Mayo Clinic in Florida.
To put that in perspective, previous studies have found the risk of having a stroke within two years is 26 percent for carotid artery disease patients with symptoms. For those without symptoms, the five-year risk of stroke is 11 percent. About half of patients in CREST had symptoms from the blockage, such as a transient ischemic attack, a non-disabling stroke or temporary vision loss. The other half had no symptoms.
“These data offer new information for Medicare,” Brott said.
Currently, Medicare – which greatly influences coverage decisions by private insurers – only covers carotid artery stenting for patients who are considered too high risk for surgery because of prior surgery or radiation to the neck, heart failure or other factors.
“Carotid stenting never really took off like many of us thought it would,” said cardiologist Deepak L. Bhatt, M.D., executive director of interventional cardiovascular programs at Brigham and Women’s Hospital in Boston, who was not involved in the CREST study but has done his own research comparing the two procedures. “If it’s not going to be reimbursed, most hospitals aren’t going to do a procedure.”
After peaking at 19,400 procedures in 2006, carotid stenting was done in 16,300 U.S. patients in 2012, according to the latest data from the Agency for Healthcare Research and Quality. By comparison, Medicare-covered carotid endarterectomy was performed in nearly 91,000 Americans in 2012, down from a high of 154,300 in 1997.
“With this large definitive study, perhaps there will be some reconsideration of whether stenting should in fact be reimbursed for patients at standard risk for surgery, meaning there would be another treatment option for patients,” Bhatt said.
Researchers found patients who underwent surgery had slightly more heart attacks, and patients who received stenting had slightly more strokes within a month after the procedure. That means for someone at risk for a heart attack, a stent might be best, whereas someone with a curvy blood vessel anatomy may be a better candidate for surgery, Bhatt said.
Opening a severely narrowed neck artery, whether with surgery or stenting, is clearly called for in people with symptoms, said Bhatt. “That patient needs a procedure,” he said. “No question, no argument.”
But using one of these procedures on people without symptoms – so-called asymptomatic patients – has been controversial because their risk for stroke is much lower and newer, more effective medicines for managing risk factors like high blood pressure and high cholesterol may offer just as much benefit. Nine out of 10 carotid artery procedures done in the U.S. are in asymptomatic patients, according to an editorial about the new research published online Thursday in the New England Journal of Medicine.
Alexander Khalessi, M.D., who was not involved in the study, performs both procedures as vice chairman of neurosurgery at the University of California San Diego Medical Center. Khalessi only treats symptomatic patients and said “advancement in medical therapy may make the procedural treatment of asymptomatic patients unnecessary.”
The last studies to pit surgery against medications in asymptomatic patients were done at least 15 years ago, Brott said, a time when carotid stenting had just been introduced and blockbuster drugs such as statins were still trickling into the market.
Although CREST confirms that patients without symptoms can benefit from the procedures, it doesn’t clarify whether either is necessary. To do that, Brott is now leading CREST-2, a study that will look at whether medications are as effective in preventing strokes as stenting and surgery. Results are expected in 2022.
For now, these new data will aid in the treatment of symptomatic patients, Khalessi said. “The complementary risk profiles liberate surgeons to offer the best procedure based on the individual patient’s anatomy and clinical comorbidities,” he said.
The CREST findings were simultaneously published in the New England Journal of Medicine, alongside results from the Asymptomatic Carotid Trial, also presented at the conference. That five-year study also found stenting worked as well as surgery in patients without symptoms or a history of a stroke.