Cerebral Autoregulation Monitoring During Cardiac Surgery

February 10, 2021 updated by: Charles W Hogue, Northwestern University

Continuous Cerebral Autoregulation Monitoring to Reduce Brain Injury From Cardiac Surgery

Neurological complications from cardiac surgery are an important source of operative mortality, prolonged hospitalization, health care expenditure, and impaired quality of life. New strategies of care are needed to avoid rising complications for the growing number of aged patients undergoing cardiac surgery. This study will evaluate novel methods for reducing brain injury during surgery from inadequate brain blood flow using techniques that could be widely employed.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Brain injury during cardiac surgery results primarily from cerebral embolism and/or reduced cerebral blood flow (CBF). The latter is of particular concern for the growing number of surgical patients who are aged and/or who have cerebral vascular disease. Normally, CBF is physiologically autoregulated (or kept constant) within a range of blood pressures allowing for stable cerebral O2 supply commensurate with metabolic demands. Cerebral autoregulation is impaired in patients undergoing cardiac surgery who have cerebral vascular disease and in many others due to other conditions. This could lead to brain injury since current practices of targeting low mean arterial blood pressure empirically (usually 50-70 mmHg) during cardiopulmonary bypass may expose patients with impaired cerebral autoregulation to cerebral hypoperfusion. The hypothesis of this proposal is that targeting mean arterial pressure during cardiopulmonary bypass to a level above an individual's lower autoregulatory threshold reduces the risk for brain injury in patients undergoing cardiac surgery. Monitoring of cerebral autoregulation will be performed in real time using software that continuously compares the relation between arterial blood pressure and CBF velocity of the middle cerebral artery measured with transcranial Doppler and with cerebral oximetry measured with near infrared spectroscopy. The primary end-point of the study will be a comprehensive composite outcome of clinical stroke, cognitive decline, and/or new ischemic brain lesions detected with diffusion weighted magnetic resonance (MR) imaging. Delirium assessed using a validated procedure that includes validated tools is a secondary outcome measure. Autoregulation is mediated by reactivity of cerebral resistance vessels. A secondary aim of this proposal is to evaluate whether near infrared reflectance spectroscopy can be used to trend changes in cerebral blood volume and provide a reliable monitor of vascular reactivity (the hemoglobin volume index). Assessments for extra-cranial and intra-cranial arterial stenosis will be performed using MR angiography to control for this potential confounding variable in the analysis. Finally, an additional aim of the study will be to assess whether preoperative transcranial Doppler examination of major cerebral arteries can identify patients who are prone to the composite neurological end-point. Near infrared oximetry is non-invasive, continuous, requires little care-giver intervention and, thus, could be widely used to individualize patient blood pressure management during surgery. Brain injury from cardiac surgery is an important source of operative mortality, prolonged hospitalization, increased health care expenditure, and impaired quality of life. Developing strategies to reduce the burden of this complication has wide public health implications.

Study Type

Interventional

Enrollment (Actual)

460

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern Memorial Hospital

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

Ages Eligible for Study

55 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Male or female patients undergoing primary or re-operative Coronary Artery Bypass Graft (CABG) and/or valvular surgery or ascending aorta surgery that requires Cardio-pulmonary bypass (CPB) who are at high risk for neurologic complications (stroke or encephalopathy) as determined by a Johns Hopkins risk score of >0.02

Exclusion Criteria:

  • Contraindication to MRI imaging (e.g., permanent pacemaker, cerebral arterial vascular clips)
  • Liver function test before surgery more than twice the upper limit of institutional normal
  • Pre-existing renal dysfunction defined as an estimated glomerular filtration rate of ≤60 mL/min, or current renal dialysis
  • Emergency surgery
  • Inability to attend outpatient visits
  • Visual impairment or inability to speak and read English. The patient will be excluded from further study if an adequate temporal window for Transcranial Doppler (TCD) monitoring can not be identified before surgery.

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

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Control
Blood pressure targets during cardiopulmonary bypass based on institutional standards of empiric management.
Device: Control group
Institutional standard of care.
Other Names:
  • Usual (Control Group)
Experimental: Intervention
Blood pressure management based on cerebral autoregulation data.
Drug: blood pressure maintenance based on cerebral blood flow autoregulation measurement
Blood pressure lowered or raised
Other Names:
  • Autoregulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Composite Neurological Outcome of Clinical Stroke or New Ischemic Brain Lesion on Diffusion Weighted MRI or Neurocognitive Dysfunction 4 to 6 Weeks After Surgery.
Time Frame: Up to 6 weeks post-operative
The composite neurological outcome was composed of clinical stroke, or new ischemic lesions detected on postoperative brain diffusion weighted magnetic resonance imaging(DWI), or cognitive decline from baseline to 4-6 weeks after surgery.
Up to 6 weeks post-operative

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Postoperative Delirium
Time Frame: Postoperative days 1-4
Assessed with Confusion Assessment Method or Confusion Assessment Method-ICU along with adjudication by team of experts
Postoperative days 1-4
Multiple Inotropic Drugs>24 Hours After Surgery
Time Frame: 7 days after surgery
Use of multiple inotropic drugs greater than 24 hours after the planned surgical procedure until discharge from the hospital.
7 days after surgery
Mechanical Lung Ventilation>24 Hours After Surgery
Time Frame: Up to 28 days after surgery.
Subjects need for mechanical lung ventilation more than 24 hours after planned surgical procedure.
Up to 28 days after surgery.
Insertion of Intra-aortic Balloon Pump
Time Frame: 7 days after surgery
Procedural insertion of intra-aortic balloon pump within 7 days after surgical procedure
7 days after surgery
Postoperative Atrial Fibrillation
Time Frame: Up to 28 days after surgery.
Clinical diagnosis of postoperative atrial fibrillation from date of surgical procedure to discharge from the hospital.
Up to 28 days after surgery.
Sepsis
Time Frame: Up to 28 days after surgery.
Clinical diagnosis of sepsis from time of surgical procedure to discharge from the hospital.
Up to 28 days after surgery.
Acute Kidney Injury Within 7 Days After Surgery.
Time Frame: 7 days after surgery
Subject developed acute kidney injury within 7 days after surgical procedure. Based on Kidney disease: Improving Global Outcomes (KDIGO) classification system.
7 days after surgery
New Renal Replacement Therapy
Time Frame: Up to 28 days after surgery.
Subjects requiring new renal replacement therapy prior to discharge from hospital
Up to 28 days after surgery.
Multisystem Organ Failure After Surgery
Time Frame: Up to 28 days after surgery.
Subject diagnosis of multisystem organ failure after surgery.
Up to 28 days after surgery.
Mortality
Time Frame: 28 days
Subject death within 28 days after surgical procedure
28 days

Collaborators and Investigators

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

Sponsor

Northwestern University

Collaborators

National Heart, Lung, and Blood Institute (NHLBI)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Actual)

September 1, 2009

Primary Completion (Actual)

February 4, 2020

Study Completion (Actual)

February 28, 2020

Study Registration Dates

First Submitted

September 21, 2009

First Submitted That Met QC Criteria

September 21, 2009

First Posted (Estimate)

September 22, 2009

Study Record Updates

Last Update Posted (Actual)

March 2, 2021

Last Update Submitted That Met QC Criteria

February 10, 2021

Last Verified

January 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 680
  • 1R01HL092259 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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.

Clinical Trials on Cardiopulmonary Bypass

Clinical Trials on Control group

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Jamaica

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe