A recent study by Brott GT et al for the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) Investigators published in N Engl J Med 2010; 363:11-23 compared carotid stenting with endarterectomy. The trial was unique in that it involved both symptomatic and asymptomatic patients with carotid stenosis and there was strict credentialing for both surgeons and interventionalists for inclusion as study operators. It is interesting to note that over a median follow up period of two and a half years, there was no significant difference in the estimated four year primary end point rates in over two thousand five hundred study patients. The primary end point was a composite of stroke, myocardial infarction or death from any cause during the periprocedural period of about one month or ipsilateral stroke within four years after randomization.
But there was higher risk of stroke during the periprocedural period in the stenting group and higher risk of myocardial infarction with endarterectomy. After that period, the events were similar in both groups.
Symptoms considered for inclusion in the symptomatic group were transient ischemic attack, amaurosis fugax or minor non-disabling stroe in the carotid territory within 6 months before randomization. Stenosis required for inclusion was 50% or more angiographic stenosis or 70% or more stenosis on ultrasonography or 70% or more stenosis on CT or MR angiography when ultrasonic stenois was reported between 50 to 69%. The eligibility criteria was different in the asymptomatic group, requiring 60% or more angiographic stenosis, 70% or more ultasonic stenosis or 80% or more stenosis on CT or MR angiographic stenosis when ultrasonic stenosis was 50 to 69%.
Distal protection devices were used for stenting whenever feasible. Aspirin and clopidogrel pretreatment was given prior to stenting and continued afer procedure. Loading dose of aspirin and clopidogrel were given when stenting occurred within 48 hours of randomization. Endarterectomy patients were pretreated with aspirin for at least 48 hours and continued after the procedure. Alternatives for aspirin were ticlopidine, clopidogrel or a combination of aspirin with extended relears dipyridamole.
The authors claim that the rate of stroke or death for the symptomatic patients with carotid stenting in their study was lower than the corresponding rates in the SPACE trial, EVA-3S trial and ICSS. The rate of stroke or death for symptomatic patients with carotid endarterectomy was also lwoer than in SPACE trial and was similar to that in EVA-3S and ICSSS. The rate of stroke or death in the carotid artery stenting group was similar to that in Asymptomatic Carotid Atherosclerosis Study (ACAS) and lower than in Asymptomatic Carotid Surgery Trial (ACST). Corresponding rates were lower for carotid endarterectomy group as well.