Consensus against both endarterectomy and routine screening for asymptomatic carotid artery stenosis

Background: Despite several randomized controlled trials, the role of carotid endarterectomy for asymptomatic patients is controversial. Validated evidence-based guidelines are needed. Methods: Thirty-five members of the Canadian Stroke Consortium, an independent body of cerebrovascular disease experts, reviewed evidence-based guidelines developed by the Canadian Task Force on the Periodic Health Examination. We held 3 rounds of Delphi consensus to solicit opinion and agreement. Results: We found a high level of interrater agreement for all guidelines using multiple statistical measures. Members agreed that evidence is insufficient to endorse carotid endarterectomy for asymptomatic patients with angiographically proven stenosis of more than 60% (kappa=0.70, P<.01). Reasons cited included concern over the reproducibility of low surgical morbidity rates in the community at large, the questionable clinical benefit conferred by surgery, and the lack of proven reduction in the risk of major disabling stroke. Screening the general population for asymptomatic stenosis was unanimously rejected. Also, screening even patients with risk factors or proven atherosclerosis at other sites was not endorsed (kappa=0.91 and kappa=0.79, respectively, both P<.01). Conclusions: There is insufficient evidence to recommend carotid endarterectomy for asymptomatic patients. Evidence is also insufficient to endorse a screening strategy even for patients with risk factors for carotid disease. While stroke prevention remains a critical goal, we do not recommend that it be accomplished by screening or by performing carotid surgery in asymptomatic patients.