Intensive Training Enhances Carotid Stenting Success

Alicia Ault

WASHINGTON -- Participation in a training program on carotid stenting can offset interventionalist inexperience, judging from the findings of a large postmarketing study of the procedure as performed in community settings, said Dr. Jay Yadav, head of vascular intervention at the Cleveland Clinic Foundation's department of cardiovascular medicine.

Speaking at a symposium sponsored by the Cardiovascular Research Foundation, Dr. Yadav concluded that a training program for physicians had contributed to the procedure's success.

Results on the first 1,603 patients in the Carotid RX Acculink/Accunet Post-Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) study were presented by Dr. Yadav. Sponsored by Guidant Corp., CAPTURE aims to look at 2,500 patients in total, with a maximum of 40 patients per facility.

In addition to determining whether stenting with Acculink/Accunet can be performed safely, CAPTURE was designed to identify and catalog rare or unanticipated events with these devices, and to evaluate Guidant's training program.

The company agreed on the program's design in collaboration with the Food and Drug Administration and the Center for Medicare and Medicaid Services. The CMS hoped to get more data on the procedure, especially in asymptomatic patients. The Acculink/Accunet system was approved in August 2004 for high-risk, symptomatic patients, but the CMS agreed to reimburse hospitals participating in CAPTURE for procedures conducted on both symptomatic and asymptomatic candidates, said Jim Neupert, vice president of marketing for Guidant Endovascular Solutions.

More than 2,000 physicians have participated since Guidant's training program began in September 2004, said Mr. Neupert. To enter the program, surgeons and interventionalists must have already performed a certain number of procedures--essentially, meeting prerequisites, he said. Training is then dependent on experience, but usually consists of 2 days of lectures and hands-on training using an anatomic model and simulator. The first three procedures are conducted with a Guidant field representative, and physicians can request a proctor at any time, Mr. Neupert said.

For patients to participate in CAPTURE, they had to be evaluated before enrollment, within 24 hours of the procedure, and 30 days post procedure by an independent neurologist. Patients also had a 30-day follow-up visit with the interventionalist who placed the stent.

The majority of patients (74%) were seen by physicians who had what was dubbed "medium" experience with stenting--that is, they had conducted 10 or fewer carotid procedures as the primary operator. Only 10% of patients were seen by physicians who had conducted five procedures as the primary operator, using Acculink and Accunet; 16% of patients were seen by physicians with "low" experience, which was defined as having conducted 25 carotid angiograms, 10 peripheral procedures with self-expanding stents, and 10 procedures with the 0.014-inch guidewire in the Acculink system.

The patients saw a variety of specialists, but most (63%) went to an interventional cardiologist. Twenty percent were operated on by a vascular surgeon or neurosurgeon, and 17% by an interventional radiologist or interventional neuroradiologist.

Dr. Yadav noted that this was primarily an older population. The mean age was 73 years, but 81% were over age 65 and 24% were over age 80. Hypertension and hypercholesterolemia were seen in 80%-90% of patients. Among the asymptomatic patients, 90% had greater than 80% stenosis; among symptomatic patients, 74% had that level of stenosis. The adverse event rate was similar to that seen in the pivotal approval study for these devices, the ARCHeR trial, noted Dr. Yadav, who serves on the study's executive committee and receives no personal funds from Guidant.

Within 30 days of the procedure, the death rate in the CAPTURE study was 1.6% (with 1.1% deemed stroke-related), compared with 2.1% in the Acculink/Accunet for Revascularization of Carotids in High-Risk Patients (ARCHeR) trial. The stroke rate was 4% (vs. 6%), and the incidence of myocardial infarction was 1% (vs. 2%).

At 5%, the stroke rate was similar in patients whose physicians had greater experience compared with those whose physicians had medium (4%) or low (5%) experience. Hospitals that had more experience had a higher stroke rate (7%) than those with medium (3%) or low (5%) experience.

Dr. Yadav said that age appeared to be an important variable, noting that patients over 80 years old had worse outcomes, but that they would still do better with stenting than with medical management.

The patients' ages and whether they were symptomatic interacted to affect mortality and morbidity. Within 30 days of the procedure, the death rate for symptomatic patients under 80 years of age was 2%, compared with 10% for the over 80 group. Eight of the 48 octogenarians who were symptomatic (17%) had a stroke, compared with 12 of the 108 patients younger than 80 years old who were symptomatic (11%).

For asymptomatic patients, the difference wasn't quite as striking. Eleven (1%) under age 80 years died within 30 days, compared with seven (2%) over 80. There were 18 strokes in the octogenarian group (6%), compared with 27 in the under 80 group (2%).

The CAPTURE findings--that physician experience doesn't seem to affect the procedure's success--is contrary to the conclusions of most previous surgical studies, noted Dr. Yadav. "The difference here is that these physicians were in an extensive training program. That seems to have negated the difference we see for most surgical procedures," he said, giving Guidant credit for its program.

"The findings described in this post-marketing study are significant for a number of reasons. The results are predictive of the "real world" application of carotid angioplasty and stenting. This is a technology that does not require a tertiary care center or a high volume practice setting. The results provide further support for the treatment of asymptomatic, greater than 80% lesions with angioplasty and stenting," said Dr. Ronald M. Fairman, chief of the division of vascular surgery, Hospital of the University of Pennsylvania, Philadelphia, when asked to comment on this presentation.

"The study supports the increasing body of evidence that symptomatic octogenarians have worse outcomes, however asymptomatic octogenarians treated with angioplasty and stenting do better that historical medical controls," he added.

"It is important to note that the majority of the procedures (> 60%) were performed by interventional cardiologists; with other subspecialists in minority. It will be important to see if the results are sustained as larger numbers of vascular surgeons and neurosurgeons embrace the technology in their practices."

Dr. Fairman is one of the site principal investigators for the CAPTURE trial and is on the executive steering committee. He owns no Guidant stock and received no personal compensation from the company.