Asymptomatic Carotid Stenosis: Cognitive Function and Plaque Correlates (ACCOF)

This study is currently recruiting participants. (see Contacts and Locations)
Verified September 2014 by Department of Veterans Affairs
Sponsor:
Collaborator:
George Mason University
Information provided by (Responsible Party):
Department of Veterans Affairs
ClinicalTrials.gov Identifier:
NCT01353196
First received: May 11, 2011
Last updated: September 8, 2014
Last verified: September 2014
  Purpose

Carotid artery plaques are known to cause stroke. Cognitive impairment is an insidious but poorly understood problem in patients with carotid plaques. Cognitive function describes how we perform mental processes such as thinking, learning and problem solving. Asymptomatic carotid plaques may affect 1 million veterans who may be at risk for cognitive impairment. In this study, we will uncover the extent of cognitive impairment in veterans with carotid stenosis who are currently labeled "asymptomatic". Programs to prevent or mitigate cognitive impairment will depend on identifying the mechanisms by which this occurs. We will use sophisticated 3D imaging techniques developed by our group to measure the structure and composition of plaques, number of particles breaking off from them, blood levels of chemicals that could disrupt them, and blood flow restriction to the brain from them. This will help identify patients at risk for cognitive impairment who may benefit from preventative measures and improve selection of patients to decrease unnecessary surgical procedures.


Condition
Cognitive Manifestations

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Asymptomatic Carotid Stenosis: Cognitive Function and Plaque Correlates

Further study details as provided by Department of Veterans Affairs:

Primary Outcome Measures:
  • composite cognitive score [ Time Frame: 2 years ] [ Designated as safety issue: No ]
    composite of multiple cognitive function test scores


Biospecimen Retention:   Samples Without DNA

blood samples for inflammatory markers


Estimated Enrollment: 284
Study Start Date: May 2011
Estimated Study Completion Date: June 2015
Estimated Primary Completion Date: June 2015 (Final data collection date for primary outcome measure)
Groups/Cohorts
Group 1
Carotid stenosis
Group 2
Controls without carotid stenosis

Detailed Description:

Carotid artery stenosis is a well-known cause of atheroembolic stroke. Stroke prevention in these patients has been the focus of intense investigation. Cognitive impairment is a more insidious but poorly understood outcome in patients with "asymptomatic" carotid stenosis who have not suffered a stroke. Cognitive function describes how a person produces and controls mental processes such as thinking, learning, and problem solving. It is an important outcome measure that affects patient well-being and their ability to live independent productive lies. It is well-known that cognitive impairment coexists in patients with stroke from carotid stenosis.

However, isolated cognitive deficits in patients with asymptomatic carotid stenosis have not been looked for, and have therefore not been reported in any detail. Asymptomatic carotid stenosis affects 2-12% of people. With 23.4 million veterans in the country, at least 1 million (4.3%) have asymptomatic carotid stenosis and are at risk for cognitive impairment. A subset analysis of the Cardiovascular Health Study found cognitive decline in 34% of 32 patients with asymptomatic carotid stenosis. In this proposal, we will define the extent of initial and progressive cognitive impairment in veterans with carotid stenosis who are currently labeled as "asymptomatic" in the absence of a focal neurologic deficit (stroke, transient ischemic attack). Programs to prevent, postpone, or mitigate cognitive impairment in patients with carotid stenosis will depend on the identification of mediators for cognitive impairment. Microembolic brain injury and cerebral hypoperfusion have been associated with cognitive impairment in elderly individuals.

Therefore plaque architecture, plaque composition, microembolic counts, serum inflammatory markers, and cerebral hypoperfusion are likely mediators of impaired cognition in patients with asymptomatic carotid stenosis. As part of this proposal, we will identify the biological mechanisms by which carotid stenosis could result in cognitive impairment. The goal of this proposal is to perform a systematic, adequately powered study to measure the magnitude of cognitive impairment in asymptomatic carotid stenosis, its impact on quality of life, and its potential pathophysiological mechanisms. Information from this study will define an unsuspected morbidity of carotid stenosis and identify subsets of patients at risk for cognitive impairment. It will form the foundation for future studies on prevention, pre-emptive treatment, or rehabilitation of patients with carotid stenosis. It will also improve the selection of patients with carotid stenosis to decrease unnecessary revascularization procedures.

Specific Aim 1 will assess if patients with asymptomatic carotid stenosis differ in cognitive function compared to age-matched controls without carotid stenosis but with similar vascular risk profiles. We hypothesize that in patients with asymptomatic carotid stenosis 50% who survive stroke free for 2 years; the change in overall and domain-specific cognitive function will be significantly different compared to those without stenosis. The study will recruit 284 subjects and will detect a clinically significant difference in cognitive score with 90% power. We will use a novel battery of cognitive tests specifically developed to address the unique issues relating to carotid stenosis. Specific Aim 2 will define plaque-morphometric, biologic, and hemodynamic characteristics that correlate with cognitive impairment in patients with asymptomatic carotid stenosis. We hypothesize that carotid plaque architecture, plaque composition, microembolic counts, serum pro-inflammatory markers, and cerebral hypoperfusion could each mediate cognitive decline over a 2-year follow-up period. We will implement a novel clinical 3D B-mode ultrasound imaging technique developed to obtain reliable serial plaque measurements. Specific Aim 3 will measure the impact of cognitive impairment on quality of life. We hypothesize that at 2 years, regardless of plaque features, cognitive impairment will correlate with a reduction in health-related quality of life measures. VA

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population

Patients eligible for the study will have asymptomatic >=50% carotid stenosis

Criteria

Inclusion Criteria:

  • asymptomatic 50% carotid stenosis

Exclusion Criteria:

  • previous stroke or transient ischemic attack (TIA)
  • severe medical illness that would interfere with evaluation of outcomes or reduce the likelihood of a 2-year follow-up
  • carotid occlusion
  • patients scheduled for carotid revascularization procedures
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01353196

Contacts
Contact: Brajesh K Lal, MD (410) 605-7000 Brajesh.Lal2@va.gov
Contact: Gregory J Kowalewski, BA (410) 605-7000 ext 4854 gregory.kowalewski@va.gov

Locations
United States, Maryland
Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD Recruiting
Baltimore, Maryland, United States, 21201
Contact: Miriam J Smyth, PhD    410-605-7130    miriam.smyth@va.gov   
Principal Investigator: Brajesh K. Lal, MD         
Sponsors and Collaborators
George Mason University
Investigators
Principal Investigator: Brajesh K. Lal, MD Baltimore VA Medical Center VA Maryland Health Care System, Baltimore, MD
  More Information

No publications provided

Responsible Party: Department of Veterans Affairs
ClinicalTrials.gov Identifier: NCT01353196     History of Changes
Other Study ID Numbers: CARA-024-10S
Study First Received: May 11, 2011
Last Updated: September 8, 2014
Health Authority: United States: Federal Government

Keywords provided by Department of Veterans Affairs:
carotid
atherosclerosis
cognitive function

Additional relevant MeSH terms:
Carotid Stenosis
Neurobehavioral Manifestations
Carotid Artery Diseases
Cerebrovascular Disorders
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Arterial Occlusive Diseases
Vascular Diseases
Cardiovascular Diseases
Neurologic Manifestations
Signs and Symptoms

ClinicalTrials.gov processed this record on October 19, 2014