CREST: CEA and CAS similar in overall long-term safety and efficacy
Published date : 27 April 2010
Article date : 27 April 2010
The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), funded by the National Institute of Neurological Disorders and Stroke with supplemental funding by Abbott Vascular, is the largest randomised clinical trial comparing the CEA to the CAS to prevent stroke among patients with and without symptoms.
The RX ACCULINK Carotid Stent System (Abbott Vascular) was the stent used in the trial, and includes a self-expanding nickel-titanium stent pre-mounted on a rapid exchange stent delivery catheter. The delivery system is comprised of a retractable sheath covering the stent during delivery, a radiopaque tip, an internal guide wire lumen, a handle assembly with a safety lock, and a pullback handle. With the handle in the unlocked position, retracting the pullback handle removes the sheath and deploys the stent. Upon deployment, the stent forms an open lattice, providing the scaffolding necessary to hold the artery open and ensure blood flow through the artery.
The stent system is available in a range of stent lengths and diameters, and in straight and tapered configurations. Stent ends should be sized between the 1.1:1 and 1.4:1 stent-to-artery ratio. Tapered stents are designed to provide appropriate stent apposition when there is a distinct difference between vessel diameters at each stent end. The proximal stent end is sized to the common carotid artery (CCA) and the distal end is sized to the internal carotid artery (ICA).
According to lead investigator, Dr Thomas G Brott, Mayo Clinic, Jacksonville, Fl, “We found that the two procedures were similar with regard to the study’s primary endpoint – overall incidence of stroke, MI and death.” He added, “We also found that the rates of these events were low, and that safety for patients with and without symptoms was as good as any reported in any randomised carotid intervention trial.”
The primary aim of CREST is to contrast the relative effectiveness of CAS versus CEA in preventing stroke, MI, and death. Researchers randomised 2,502 patients – 35% were female and 9% minorities – to receive either CEA or CAS at more than 100 North American hospitals. More than 80% of the participants had an artery blockage greater than 70%.
The prospective, randomised, parallel, two-arm, multi-centre trial included patients who have experienced a transient ischaemic attack (TIA), amaurosis fugax (AF), or non-disabling stroke within the past 180 days, and who have an ipsilateral carotid stenosis >=50% by angiography or >=70% by ultrasound or >= 70% by CTA or MRA. Also included were patients who have carotid stenosis >=60% by angiography or >=70% by ultrasound or >= 80% by CTA or MRA.
Excluded patients included those who have comorbid conditions that interfere with the evaluation of endpoints, that are known to interfere with the completion of CEA or CAS, or that affect the likelihood of survival for the four-year study period.
Dr Brott and his colleagues found that in the 30-day period following the procedure, the rate for stroke was 2.3% in the surgical patients and 4.1% in the stenting group. However, the MI rate was higher in the surgical group, 2.3%, compared to 1.1% in the stenting group. The difference in MI and stroke between the two groups was statistically significant, explained Brott.
The researchers also found that the age of the patient made a difference in outcome. 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.
Furthermore, researchers found that symptomatic and asymptomatic patients, and males and females, had similar outcomes in the surgical and stenting groups.
“For the present, stenting offers a reasonable alternative to carotid artery surgery,” Brott said. “For younger patients, carotid stenting appears to be a very useful tool,” he concluded.
