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Cerebral Autoregulation Monitoring During Cardiac Surgery

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00981474
Recruitment Status : Completed
First Posted : September 22, 2009
Results First Posted : March 2, 2021
Last Update Posted : March 2, 2021
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Charles W Hogue, Northwestern University

Brief Summary:
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.

Condition or disease Intervention/treatment Phase
Thoracic Surgery Cardiopulmonary Bypass Drug: blood pressure maintenance based on cerebral blood flow autoregulation measurement Device: Control group Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 460 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Continuous Cerebral Autoregulation Monitoring to Reduce Brain Injury From Cardiac Surgery
Actual Study Start Date : September 1, 2009
Actual Primary Completion Date : February 4, 2020
Actual Study Completion Date : February 28, 2020

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Heart Surgery

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 Name: 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 Name: Autoregulation

Primary Outcome Measures :
  1. 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.

Secondary Outcome Measures :
  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. Sepsis [ Time Frame: Up to 28 days after surgery. ]
    Clinical diagnosis of sepsis from time of surgical procedure to discharge from the hospital.

  7. 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.

  8. New Renal Replacement Therapy [ Time Frame: Up to 28 days after surgery. ]
    Subjects requiring new renal replacement therapy prior to discharge from hospital

  9. Multisystem Organ Failure After Surgery [ Time Frame: Up to 28 days after surgery. ]
    Subject diagnosis of multisystem organ failure after surgery.

  10. Mortality [ Time Frame: 28 days ]
    Subject death within 28 days after surgical procedure

Information from the National Library of Medicine

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, Learn About Clinical Studies.

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Ages Eligible for Study:   55 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00981474

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United States, Illinois
Northwestern Memorial Hospital
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Northwestern University
National Heart, Lung, and Blood Institute (NHLBI)
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Principal Investigator: Charles Hogue, MD Northwestern University
  Study Documents (Full-Text)

Documents provided by Charles W Hogue, Northwestern University:

Publications automatically indexed to this study by Identifier (NCT Number):

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Responsible Party: Charles W Hogue, Professor, Northwestern University Identifier: NCT00981474    
Other Study ID Numbers: 680
1R01HL092259 ( U.S. NIH Grant/Contract )
First Posted: September 22, 2009    Key Record Dates
Results First Posted: March 2, 2021
Last Update Posted: March 2, 2021
Last Verified: January 2021
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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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
Keywords provided by Charles W Hogue, Northwestern University:
cardiac surgery; brain injury; cerebral autoregulation
Additional relevant MeSH terms:
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Brain Injuries
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Craniocerebral Trauma
Trauma, Nervous System
Wounds and Injuries