Long-term Observational Extension of CREST-2


About this study

The purpose of this study is a long-term observational extension of the CREST-2 trial (C2LOE) to describe the comparative treatment effectiveness over a longer period of expected benefit from revascularization than can be accomplished in the parent trial alone. CREST-2 is a multicenter randomized trial of intensive medical management (IMM) with or without revascularization in patients with asymptomatic high-grade carotid stenosis (ClinicalTrials.gov Identifier: NCT02089217).

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Eligibility for the parent CREST-2 trial included male and female individuals who are ≥ 35 years old and who have high-grade asymptomatic stenosis involving the cervical internal carotid artery.
  • A patient is considered asymptomatic in the absence of ipsilateral symptoms < 180 days prior to randomization.
  • Carotid stenosis is defined as high-grade if catheter angiography documents ≥ 70% stenosis per criteria used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET) or duplex ultrasonography (DU) documents peak systolic velocity (PSV) of ≥ 230 cm/s in combination with at least one of the following four criteria: end diastolic velocity of ≥ 100 cm/s, internal carotid artery-to-common carotid artery PSV ratio ≥ 4.0, computed tomography angiogram (CTA) showing ≥ 70% stenosis, or a magnetic resonance angiogram (MRA) showing ≥ 70% stenosis.
  • All currently active patients in the CREST-2 trial will be eligible for C2LOE. 
  • Most CREST-2 participants are Anglophone; however, there are also a small number of native French speakers (largely in Quebec, Canada) and native Spanish speakers (largely in Florida, Texas, and California sites, as well as the Barcelona, Spain center).
  • The Survey Research Unit (SRU) conducting the interviews can perform assessments in both French and Spanish, allowing inclusion of these patients in the long-term follow-up.

Exclusion Criteria:

  • Inability to secure written informed consent to be followed in this protocol.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Jacksonville, Fla.

Mayo Clinic principal investigator

James Meschia, M.D.

Closed-enrolling by invitation

What is this? (?)
Not open to everyone who meets the eligibility criteria, but only those invited to participate by the study team.

Contact information:

James Meschia M.D.

(904) 953-6012


More information


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