Long-term Neurocognitive Sequelae of Subclinical Microembolization During Carotid Interventions

Microembolization is commonly associated with carotid artery stenting (CAS), but our understanding of subclinical microembolization is superficial. Through collaborative effects of multidisciplinary team-experts, novel approaches, and longitudinal evaluations, we hope to better understand the clinical significance and long-term cognitive effects of microemboli. This proposal may change our current clinical practice by providing a better outcome measure for carotid interventions and improving outcomes of CAS procedures through risk factor stratification. Our central hypothesis is that development of subclinical microemboli is associated with decline in cognitive function following CAS and that the risk of development of microemboli themselves is associated with patient- and procedure-related factors. We hope that this prospective study will help to clarify these important issues in the era of rapidly evolving percutaneous interventions.

Study Overview

• Status: Completed
• Conditions: Carotid Artery Stenosis
• Intervention / Treatment: Behavioral: Neuropsychological testing

• Study Type: Observational
• Enrollment (Actual): 207

Contacts and Locations

Study Locations

• United States
  • California
    • Palo Alto, California, United States, 94304
      • Palo Alto Veterans Affairs
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University School of Medicine
  • Wisconsin
    • Madison, Wisconsin, United States
      • University of Wisconsin, Madison

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing carotid intervention

Description

Inclusion Criteria:

• Patient is male or female >40 yrs of age.
• Patient has occlusive extracranial carotid stenosis (≥70%)
• Patient is scheduled to undergo an endovascular intervention of a lesion in the extracranial carotid artery
• Patient agrees to voluntarily participate and signs an informed consent.
• Patient agrees to be available for follow-up and is able to participate in all study testing procedures.
• Patient has sufficient visual and auditory acuity for cognitive testing.

Exclusion Criteria:

• Patient is unable to safely and comfortably undergo magnetic resonance imaging procedures (e.g., claustrophobia, implanted medical devices that are MRI incompatible such as pacemaker, defibrillator, neural stimulator etc)
• Patient has an untreated or unsuccessfully controlled psychiatric disease (schizophrenia, bipolar disorder).
• Patient has prominent suicidal or homicidal ideation.
• Patient has acute illness or unstable chronic illness (e.g. uncontrolled hypertension, hepatic encephalopathy, portal hypertension, ascites, and esophageal varices, pancreatitis).
• Patient with a history of neurological (e.g., multiple sclerosis, seizure disorder, Parkinson's disease) or systemic illness affecting central nervous system function.
• Patient has prior closed head injury with ≥24 hours of amnesia.
• Patient is unable to understand or sign the informed consent.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Neuroimaging Correlates; Carotid revascularization can significantly reduce the risk of stroke in patients with severe carotid stenosis; however, it has been associated with cognitive decline in 25% of the older adults who undergo the procedure. Neuroimaging techniques that characterize white matter integrity and regional hypoperfusion have the potential to provide sensitive brain structure indicators that may be associated with memory decline following revascularization procedures. In this proposal, we hope to determine the risk factors and cognitive effect of microembolization following carotid revascularization procedures.

Behavioral: Neuropsychological testing

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Incidence of microemboli in correlation with changes in neurocognitive assessment performance	1 year following CAS procedure

Secondary Outcome Measures

Outcome Measure	Time Frame
Risk factor stratification for incidence of microemboli	1 year following CAS procedure

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: Washington University School of Medicine; University of Wisconsin, Madison

Publications and helpful links

General Publications

• Zhou W, Hitchner E, Gillis K, Sun L, Floyd R, Lane B, Rosen A. Prospective neurocognitive evaluation of patients undergoing carotid interventions. J Vasc Surg. 2012 Dec;56(6):1571-8. doi: 10.1016/j.jvs.2012.05.092. Epub 2012 Aug 11.

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2011
• Primary Completion (Actual): April 1, 2018
• Study Completion (Actual): April 1, 2018

Study Registration Dates

• First Submitted: October 29, 2012
• First Submitted That Met QC Criteria: October 29, 2012
• First Posted (Estimate): October 31, 2012

Study Record Updates

• Last Update Posted (Actual): August 29, 2022
• Last Update Submitted That Met QC Criteria: August 24, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Keywords: MRI; neuropsychological testing; carotid artery stenting; microembolization
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Vascular Diseases; Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Arterial Occlusive Diseases; Carotid Artery Diseases; Carotid Stenosis
• Other Study ID Numbers: R01NS070308 (U.S. NIH Grant/Contract)