Adapting to Evolving Technologies and Treatment Guidelines in a Procedural Trial: A Qualitative Review of the CREST-2 Experience.

Multiple challenges confront procedural trials, including slow enrollment, lack of equipoise among patients and physicians, and failure to achieve adequate masking. Nonetheless, randomized clinical trials provide the best evidence of efficacy. The evolution of technology, techniques, and standards of care during the conduct of procedural trials challenges external validity. Herein, we review how a multicenter trial of revascularization of asymptomatic carotid arteries for stroke prevention has managed changes in treating carotid stenosis and medical management of atherothrombotic disease.