The CDAC Study - Cerebral Dysfunction After Coronary Revascularization (CDAC)

March 19, 2026 updated by: Robert Russo, The Scripps Research Institute
Neurocognitive decline has long been suspected to be a potential long-term complication of coronary artery bypass grafting surgery (CABG), with reports of post-operative cognitive dysfunction by objective testing approaching 15-50% of patients in the year following surgery. To determine the true rate of long-term cognitive dysfunction following CABG compared to percutaneous coronary intervention (PCI or coronary stent placement), we propose a multi-center, two-group, non-randomized study using computer-based customized neurocognitive testing (Cogsate), prior to the procedure and then at 30 days, 1-year and 2-years after revascularization to evaluate cognitive function vital for the maintenance and advancement of professional and personal activities. It is anticipated that the study will document a higher rate of cognitive dysfunction in the CABG group, that the landmark study will provide both the patient and physician with the information necessary to make an informed decision regarding the cognitive risks of CABG versus PCI when faced with the need for coronary revascularization, and that these results will change the clinical practice of recommending CABG as a primary revascularization option for those wishing to preserve cognitive function.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Neurocognitive decline has long been acknowledged as a potential complication of coronary artery bypass grafting surgery (CABG). The incidence of post-operative cognitive dysfunction (POCD) as measured by objective testing has been reported in several small studies to approach 15-50%, with great variability noted in study size, testing methods, and length of clinical follow-up. However, much controversy exists regarding the prevalence and severity of post-operative cognitive changes following CABG, as well as the methods of assessment. Currently, pre-revascularization discussions between a treating physician and a patient (Informed Consent) are limited to topics of morbidity, mortality, and surgical result, and these discussions do not include the potential risk of POCD. In contrast to CABG, percutaneous coronary intervention (PCI), including stent placement, has the potential of providing similar revascularization results without the risk of POCD or a negative impact on personal and professional quality of life. Thus, to determine the true rate of cognitive dysfunction for patients in 2 years following CABG compared to patients undergoing PCI, we propose a multi-center, observational, two-group, non-randomized cohort study. The decision to undergo CABG or PCI will be made by a treating physician and a patient before study enrollment, and thus, the choice of a procedure is not part of the research protocol, and there is no increased risk due to study enrollment. Patients at 30 centers will undergo baseline computer-based customized neurocognitive testing (Cogstate), chosen for its sensitivity to detect cognitive changes in multiple domains. Initial testing will be >48 hours after the qualifying diagnostic coronary angiogram and <2 months before CABG or PCI. The test will be repeated 30 days after hospital discharge and again at 1- and 2-years after revascularization. Diagnostic angiographic images will later be evaluated by three physicians to determine if the patients could have received similar results from CABG or PCI. Due to ethical concerns, randomization to a treatment option is not appropriate. While inferring causality in the absence of a randomized clinical trial design may be challenging, propensity score matching will be employed to enhance the efficiency of measured clinical variables or characteristics. The primary study endpoint is a change of within-patient cumulative computer-based neurocognitive test performance at baseline, with comparison to 2-years after revascularization (in addition to between-group comparisons). Secondary endpoints include test results 30 days and 1-year after discharge compared to baseline, return to work or usual activities interval, and a change in professional status, job title, or personal activities. Thus, the present study for the first time will provide both patient and physician with the information necessary to make an informed treatment decision when faced with the need for coronary revascularization, and the desire to maintain cognitive function, professional productivity and personal quality of life, and may also change the method of cognitive testing and the clinical practice of recommending CABG as a primary revascularization option.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
600

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The CDAC Study is an observational, two-group, non-randomized cohort of 600 patients undergoing elective CABG or PCI

Description

Inclusion Criteria:

  • Criteria for enrollment are age 18 years or more.
  • A candidate for either elective single or multi-vessel CABG or PCI without limits for lesion location, lesion characteristics or complexity, the number of vessels treated, or the number of stents or bypass grafts placed, or the type of bypass grafts.
  • The decision to undergo either CABG or PCI will be made by the treating physician and patient before research study enrollment, and thus, the revascularization decision is not directed by this research protocol.

Exclusion Criteria:

Patients will not be enrolled due to:

  • Concomitant valve therapy (surgical or transcatheter).
  • Prior CABG or surgical valve repair/replacement surgery.
  • PCI within 1 year of the study entry procedure.
  • A hybrid revascularization procedure (PCI plus CABG), an untreated carotid artery stenosis of >70%, inability to provide informed consent.
  • The inability to perform pre-procedure tablet-based neurocognitive testing.
  • The lack of stated agreement to return for follow-up on-site neurocognitive testing at the prescribed time points.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in neurocognitive testing
Time Frame: 2 years
A change of within-patient cumulative Cogstate computer-based neurocognitive test performance.
2 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in neurocognitive testing
Time Frame: 1 month
A change in within-patient neurocognitive test performance at baseline compared to 1-month after revascularization discharge
1 month
Change in neurocognitive testing
Time Frame: 1 year
A change in within-patient neurocognitive test performance at baseline compared to 1-year after revascularization discharge
1 year
Incidence of stroke or TIA
Time Frame: 2 years
Stroke or TIA
2 years
New diagnosis of a Mood Disorder
Time Frame: 2 years
The new diagnosis of a mood or neurodegenerative movement disorder
2 years
The new need for Psychiatry
Time Frame: 2 years
The need for psychiatry or behavioral medicine therapy with or without the use of medications
2 years
Questionnaire regarding work
Time Frame: 2 years
Return to work interval
2 years
Questionnaire regarding return to independent activities
Time Frame: 2 years
A return to usual or independent activities of daily living interval
2 years
Questionnaire regarding return to their job
Time Frame: 2 years
Change in professional status or job title, responsibilities, or income.
2 years
Questionnaire regarding return to social activities
Time Frame: 2 years
A change in personal/social activities
2 years
Questionnaire regarding return to daily activities
Time Frame: 2 years
A change in the ability to perform activities of daily living present at baseline, both Basic (eating, dressing, bathing, toileting, managing continence, and transferring), and Instrumental (cooking, cleaning, transportation, laundry, and managing finances)
2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
The Scripps Research Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2027

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 1, 2032

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
January 1, 2033

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 16, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 19, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 24, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 24, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 19, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Russo_CDAC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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