In the randomised stroke prevention trials, the Carotid Revascularisation Endarterectomy vs Stenting Trial (CREST) took place at 117 centers in the US and Canada over a nine-year period. CREST compared the safety and effectiveness of CEA and CAS in patients with or without a previous stroke.
The trial was funded by the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health (NIH), and led by investigators at Mayo Clinic, Jacksonville, Fla, and the University of Medicine and Dentistry of New Jersey in Newark. Additionally, partial funding for the study was supplied by Abbott, maker of the stents.
The overall safety and efficacy of the two procedures was largely the same with equal benefits for both men and for women, and for patients who had previously had a stroke and for those who had not. However, when the investigators looked at the numbers of heart attacks and strokes, they found differences. The investigators found that there were more heart attacks in the surgical group, 2.3 % compared to 1.1% in the stenting group; and more strokes in the stenting group, 4.1% versus 2.3% for the surgical group in the weeks following the procedure.
The study also found that the age of the patient made a difference. At approximately age 69 and younger, stenting results were slightly better, with a larger benefit for stenting, the younger the age of the patient. Conversely, for patients older than 70, surgical results were slightly superior to stenting, with larger benefits for surgery, the older the age of the patient.
In CREST, approximately half the patients had recent symptoms due to carotid disease such as a minor stroke, or a transient ischemic attack (TIA), indicating a high risk for future stroke. The other half had no symptoms but were found to have narrowing of the carotid artery on one of a variety of tests assessing carotid narrowing and plaque. Such patients, termed asymptomatic, are at much lower risk of stroke than those with symptoms.
The CREST investigators concluded that while CEA has a proven record and long term durability, both CAS and CEA are safe and useful tools in the right setting for stroke prevention, and technology continues to improve each procedure.
Thomas Brott, professor of neurology and director for research at Mayo Clinic and the national principal investigator of the study, said: “The CREST trial results show that we now have two safe and effective methods to treat carotid artery disease directly, the tried and true CEA, and the new kid on the block, CAS. There was evidence that people who were younger than 70 did better with stents while those over 70 had better results with the surgery, but the results for all men and women were excellent.”
Gary Roubin, lead investigator for CREST and study co-principal investigator for stenting, said: “Although the purpose of the study was to compare the two procedures, we were pleased to find that both CEA and stenting have become extraordinarily safe. The rate for stroke and death in carotid stenting was also the lowest yet reported in any randomised trial, and significant advances in technology, technique and patient selection for stenting have continued over the eight-year enrollment in CREST.”