THURSDAY, March 25, 2004 (HealthDayNews) -- Two trials have found that stenting of the carotid arteries, the main arteries in the neck that supply blood to the brain, are effective for high-risk patients.
Results of the ARCHeR trial, which looked at extremely high-risk patients, and the SAPPHIRE trial were presented Thursday at the 29th annual meeting of the Society of Interventional Radiology in Phoenix.
In both groups of patients, stenting was found to be superior to a conventional procedure called carotid endarterectomy surgery. Stenting is the use of a tube-like device in the coronary artery to keep the vessel open.
Narrowing of the carotid arteries is a major risk factor for ischemic stroke. Up till now, the standard procedure for blocked carotid arteries has been endarterectomy surgery, which removes plaque from the vessels.
The so-called ARCHeR trial assessed the effectiveness of carotid artery stenting with and without embolic protection. Embolic protection is a tiny umbrella-like device to capture debris that might break off during the procedure.
Almost 600 patients were placed in three different arms of the trial: ARCHeR 1, which used the stent on its own; ARCHeR 2, which used the stent plus embolic protection; and ARCHeR 3, which used a newer version of catheters for placing the stent.
At the end of 30 days, ARCHeR 1, 2, and 3 patients had rates of major adverse events of 7.6, 8.6, and 8.3 percent, respectively. The incidence of major stroke or death was 3.8, 2.5, and 2.8 percent, respectively.
At the end of one year, the rate of major adverse events was 8.3 and 10.2 percent for ARCHeR 1 and 2, respectively (data for ARCHeR 3 is not yet available). This was compared to 14.5 percent for surgery patients.
"There were no additional major strokes in ARCHeR 1 and only one in ARCHeR 2," says Dr. Mark Wholey, co-principal investigator of this trial and a member of the executive committee for the SAPPHIRE trial. "There were four minor strokes and all had come back to normal baseline. That was in itself quite impressive."
Yet this is not the final word for some experts.
"The ARCHeR study did not randomize patients," says Dr. Enrico Ascher, chairman of the Vascular Institute at Maimonides Medical Center in New York City. "One would feel that it's logical to believe that a minimally invasive procedure carries less risk than an open procedure. However, it is also known for five decades that carotid endarterectomy is not a dangerous procedure. It is a very safe procedure."
The second trial, called SAPPHIRE, looked at carotid stenting vs. surgery in high-risk diabetic patients.
At 30 days, the incidence of stroke, heart attack or death was 4.8 percent in the stenting group and 22.7 percent in the surgery group.
At one year, the major adverse event rate was 4.8 percent for stenting and 25 percent for surgery. The heart attack rate at this point in time was 2.4 percent in the stenting group and 18.2 percent in the surgery group. Only 2.4 percent in the stenting group had a stroke compared with 11.4 percent in the surgery arm. The differences, Wholey says, were "mind blowing."
"In the high-risk diabetic population, if one can believe the data from SAPPHIRE, stenting is clearly a more favorable option than surgery," Wholey adds. "Now it's true that this is not the most heavily powered study, but nonetheless the incidence of myocardial infarction [heart attack] and stroke were statistically significant."
The U.S. Food and Drug Administration had originally mandated that stents could only be investigated in high-risk patients. "What is clearly needed now is to proceed with low-risk trials," Wholey says.