PHOENIX—High-risk surgical patients with diabetes who underwent carotid stenting had fewer heart attacks and significantly fewer major adverse events overall at one-year follow-up than did patients who underwent carotid endarterectomy to prevent stroke. According to data presented at the 29th Annual Scientific Meeting of the Society of Interventional Radiology, the stenting group had a 2.4% incidence of heart attacks compared with an 18.2% incidence in the endarterectomy group. Incidence of major bleeding was 4.8% for the stenting group versus 20.5% for the endarterectomy group, the investigators reported.

The study also collected the 30-day event rate for any type of stroke, heart attack, or death. The 30-day event rate for stroke, heart attack, or death was 4.8% for stenting and 22.7% for carotid surgery and was statistically significant, the researchers noted. The findings are based on data from the high-risk diabetic arm of the SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy) trial, a prospective, multicenter, randomized, controlled trial at 29 US centers comparing the safety and efficacy of carotid stenting with embolic protection to standard carotid surgery to treat blocked carotid arteries to prevent stroke.

“These findings are quite significant because diabetics are at greater risk for all vascular events. This study shows that stenting is far safer than surgery even in this highest risk population. It clearly establishes that all high-risk diabetics should have stenting, not surgery,” said Mark Wholey, MD, a SAPPHIRE trial principal investigator and Chairman of the Pittsburgh Vascular Institute at the University of Pittsburgh Medical Center Shadyside Hospital.

A LOW-RISK INTERVENTION FOR A HIGH-RISK POPULATION

Patients with diabetes are at greater risk in general for vascular conditions including peripheral arterial disease, carotid artery disease and stroke, coronary artery disease and heart attack, and abdominal aortic aneurysm. Because they are prone to vascular disease and calcification, their arteries are less elastic, making them more prone to artery dissection and reclogging of the artery after treatment. They have a high complication rate for surgery but are also more difficult to treat with angioplasty and stenting, noted Dr. Wholey. “These findings offer hope for those patients who need treatment of their carotid artery disease to prevent stroke but were too high risk to have the surgery. Now we know we can safely offer them carotid stenting,” he said.

In addition to the lesser risk of major adverse events, there are many other benefits to the balloon angioplasty and stenting treatment, Dr. Wholey commented. Because there is no incision, there is no damage to the cranial nerves that can occur with endarterectomy and can cause difficulty talking and swallowing. Cranial nerve damage occurred in 4.8% of the overall SAPPHIRE trial surgical patients and has been reported to be as high as 9% in other surgical studies, he said. Moreover, the patient can go home the next day, there is no general anesthesia and no infection rate, and the interventional procedure takes only about 20 to 30 minutes.

A GEM OF A STUDY

The study involved a total of 334 high-risk patients who were randomized and treated by either stenting with embolic protection or surgery in the overall multicenter SAPPHIRE trial; the high-risk diabetic subset was composed of 86 patients. “All of the SAPPHIRE trial patients were high risk, and the earlier data on the total study population showed the stenting to be safer than surgery. This diabetic subset was at even higher risk, and these new data not only substantiate and confirm the earlier findings but show even more dramatically that stenting is safer than surgery in those at high risk,” Dr. Wholey said.

The primary end points of the study measured the 30-day major adverse event rates, which were likely to be procedure-related events, and the one-year major adverse event rates, which included the 30-day rate plus death and ipsilateral stroke from 31 days to one year.

SAPPHIRE DATA

The 30-day major adverse event rate included death and any stroke or heart attack. In the high-risk diabetic population, the 30-day major adverse event rate was 4.8% for the stenting group and 22.7% for the carotid endarterectomy group, which was statistically significant.

The overall one-year major adverse event rate was 16.7% for the stenting group versus 31.8% for the endarterectomy group, showing a trend favoring carotid stenting. The increase in the event rate from the 30-day to the one-year mark was largely attributed to the nonneurologic deaths from congestive heart failure, myocardial infarction, and/ or other nonneurologic comorbidities. However, the combination of the 30-day major adverse event rate with ipsilateral strokes and deaths due to stroke (neurologic death) from 31 days to one year resulted in a major adverse event rate that was 4.8% for stenting versus 25% for endarterectomy at one year and was statistically significant, Dr. Wholey noted.

Statistically significant differences at one-year follow-up were also observed for stenting over endarterectomy for heart attack (2.4% versus 18.2%) and major bleeding (4.8% versus 20.5%), he added. The incidence of stroke in diabetic patients was lower in the stenting group at 2.4% compared to 11.4% in the endarterectomy group, but the difference was not statistically significant.

“We thought the initial SAPPHIRE results in the overall high-risk patients were exciting,” Dr. Wholey said. “However, these new data from the high-risk diabetic subset show even more dramatically the beneficial effects of stenting versus surgery in this subset.”

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Suggested Reading
Wholey MH, Jarmolowski CR, Wholey M, Eles GR. Carotid artery stent placement—ready for prime time? J Vasc Interv Radiol. 2003;14:1-10.

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