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Dr. Dennis Bandyk

Florida Hospitals Play Vital Role in Landmark Clinical CREST Study
 

At the American Stroke Association’s International Stroke Conference held earlier this year, results were released of an NIH-funded landmark clinical stroke prevention trial that may represent the world’s largest study of its kind.

The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) compared two types of treatment for the narrowing of carotid arteries to determine their efficacy in preventing stroke in patients with this condition. CREST represents the largest randomized clinical trial comparing the traditional surgical approach (carotid endarterectomy or CEA) to the newer non-surgical approach (carotid stenting or CAS) to prevent stroke among patients with carotid narrowing, with or without associated symptoms. Seven clinical centers in Florida were among 117 participating centers—27 in the South—in the United States and Canada.

Participating Clinical Centers in Florida To be selected as a CREST trial site, hospital teams were thoroughly evaluated to assure that standards were met for proven excellence in caring for patients with carotid artery disease, including exceeding benchmark results for both CAE and CAS. • Florida Hospital Orlando in Orlando • Orlando Regional Medical Center in Orlando • Miami Cardiac and Vascular Institute in Miami • Leesburg Regional Medical Center in Leesburg • Morton Plant Hospital in Clearwater • Mayo Clinic in Jacksonville  • University of South Florida Tampa General in Tampa   SOURCE: National Institutes of Health.

Overall, the study found the two procedures were similar with regard to the study’s primary endpoint—stroke, heart attack or death—and rates of endpoint events were very low. Also, safety for patients—with and without symptoms—was on par with reports in other randomized carotid intervention trials, said investigators.

“In properly selected patients, the treatment of both symptomatic and asymptomathic internal carotid stenosis had similar outcomes with surgery or carotid stent angioplasty,” said Dennis Bandyk, MD, professor of surgery and chief of vascular surgery at the University of South Florida (USF), chief of surgery at Tampa General Hospital, and the local principal investigator for the CREST trial. “The CREST data indicate the patient can participate in the decision of the best treatment option.”

The basic problem with carotid artery occlusive disease is the development of atherosclerosis plaque buildup in the carotid artery. If plaque forms in either carotid artery, and the degree of narrowing becomes severe, then the patient is at significantly increased risk of stroke occurrence. Carotid intervention is the focus of stroke occurrence prevention.

“The CREST study and other prior clinical trials indicate it’s the severity of carotid stenosis … the best predictor of stroke …. (and) treatment of severe less than 70-80 stenosis was found to reduce stroke occurrence,” said Bandyk.

CREST researchers enrolled 2,502 patients who will be followed for up to 10 years from the time of procedure. The study involved two types of patients with a partial carotid blockage. Symptomatic participants had suffered a non-disabling stroke or a transient ischemic attack (TIA) within the previous six months. Asymptomatic patients had not had a stroke or TIA during the same time span. Of the participants, 35 percent were female and 9 percent represented minorities. More than 80 percent of the patients had an artery blockage greater than 70 percent.

“At USF, both women and men were enrolled in the CREST study,” said Bandyk. “Our study site experienced no strokes with intervention. Our experience with carotid angioplasty hasn’t demonstrated an increased procedure stroke risk in the older (than 80 years of age) patient.”

Patient age played an unexpected role in CREST results.

“The study showed, counter-intuitively, that results tended to be better with CAS for younger patients and better with CAE for older patients, with a threshold for difference at 69 years of age,” explained vascular surgeon Charles S. O’Mara, MD, CREST primary investigator at Baptist Medical Center in Jackson, Miss. “It’s also interesting, if not surprising, that outcomes were similar for symptomatic and asymptomatic patients and for men and women, again using the primary endpoint of combined stroke, MI, and death.”

CREST adds to a growing body of conflicting clinical data about the efficacy of CAS, a procedure approved by the FDA several years ago for clinical use but without reimbursement from the Centers for Medicare & Medicaid Services (CMS) under usual circumstances.

The conflicting nature of this data was underscored by the publication of a European study (ICSS) in Lancet, the day before the CREST results were released, which showed significantly higher rates of stroke, death, or MI in patients treated with CAS compared to CEA.

Also, CMS continues to have a policy of non-coverage for CAS, except under the restrictive circumstance of a patient with the combination of recent symptoms, high-grade stenosis, and high risk for surgery. Collective information suggests that CEA remains the frontline treatment for carotid stenosis. However, CAS may be more effective in certain situations, such as those in which local anatomy makes risk of CEA higher than usual. Also, evolution of technology, advances in medical management, and accrued information from further analysis of data from CREST and other studies may modify treatment recommendations in the future.

“The conflict exists when comparing U.S. data with results from Britain and Europe,” said Bandyk. “The interventionists in those countries have experienced increased procedural events with both surgery and carotid stent-angioplasty. This has been attributed to the experience of the vascular surgeons and interventionists. It’s the opinion of U.S. vascular surgeons that CMS should provide payment for CAS procedures.”

Interestingly, a point of contention in the CREST findings revolves around the primary endpoints of stroke, myocardial infarction (MI) or death. CREST findings also showed that risk of stroke was significantly higher (about two-fold) for patients with CAS, while the risk of MI (defined by EKG changes or chest pain plus cardiac enzyme elevation) was significantly higher (also, about two-fold) for CAE.

“Results of combining those three end points were similar at about 7 percent in both CAS and CAE arms of the trial,” said O’Mara. “On the surface, you’d interpret these data to indicate that both procedures are comparable, but like any other complex study involving many variables, if you drill down beyond those three primary endpoints, you see some important differences.”

Bandyk concurred with the main point. “Each institution and physician needs to assess their own results,” he said. “Our experience at USF and Tampa General is that CAS is a less morbid procedure than CEA, and with proper patient selection, the CAS procedure can be performed with a low (less than 3 percent) stroke rate.”

For the endpoints of stroke and death, CEA was shown to be the safer procedure. Only when the MI endpoint was added did the results of the two procedures become similar. Also, assessment of quality of life after recovery documented a significantly greater adverse impact of stroke than that of MI in CREST participants.

“Since the CREST was performed, the technology and thus safety of CAS has improved,” said Bandyk.

The National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health (NIH), with supplemental funding by Abbott, funded CREST.

Tags:

Abbott, American Stroke Association, Carotid Revascularization Endarterectomy Versus Stenting Trial, CREST, Dr. Dennis Bandyk, International Stroke Conference, National Institute of Neurological Disorders and Stroke, National Institutes of Health, NIH, NINDS, Tampa General Hospital, University of South Florida.

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