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Cerebral Autoregulation Monitoring During Cardiac Surgery

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified September 2009 by Johns Hopkins University.
Recruitment status was:  Recruiting
National Heart, Lung, and Blood Institute (NHLBI)
Information provided by (Responsible Party):
Charles W. Hogue, Johns Hopkins University Identifier:
First received: September 21, 2009
Last updated: March 7, 2013
Last verified: September 2009
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 Intervention Phase
Thoracic Surgery
Cardiopulmonary Bypass
Other: blood pressure maintenance based on cerebral blood flow autoregulation measurement
Other: Control group
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Continuous Cerebral Autoregulation Monitoring to Reduce Brain Injury From Cardiac Surgery

Resource links provided by NLM:

Further study details as provided by Johns Hopkins University:

Primary Outcome Measures:
  • 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: Perioperative ]

Estimated Enrollment: 280
Study Start Date: September 2009
Estimated Study Completion Date: August 2014
Estimated Primary Completion Date: June 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Intervention
Blood pressure targets during cardiopulmonary bypass based on real-time cerebral blood flow autoregulation monitoring results.
Other: blood pressure maintenance based on cerebral blood flow autoregulation measurement
Blood pressure lowered or raised to level above an individuals autoregulatory limits
Active Comparator: Control
Blood pressure targets during cardiopulmonary bypass based on institutional standards of empiric management.
Other: Control group
Blood pressure management based on institutional standard of care.

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. 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.

Ages Eligible for Study:   60 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male or female patients undergoing primary or re-operative CABG and/or valvular surgery that requires CPB who are at high risk for neurologic complications (stroke or encephalopathy) as determined by a Johns Hopkins risk score of >0.1

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 TCD monitoring can not be identified before surgery.
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Please refer to this study by its identifier: NCT00981474

Contact: Charles W Hogue, MD 410-614-1516

United States, Maryland
The Johns Hopkins Hospital Recruiting
Baltimore, Maryland, United States, 21287
Contact: Shannon Ledroux, BSN    410-955-8567   
Principal Investigator: Charles W. Hogue, MD         
Sponsors and Collaborators
Johns Hopkins University
National Heart, Lung, and Blood Institute (NHLBI)
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Charles W. Hogue, Professor, Johns Hopkins University Identifier: NCT00981474     History of Changes
Other Study ID Numbers: 680  1R01HL092259 
Study First Received: September 21, 2009
Last Updated: March 7, 2013

Keywords provided by Johns Hopkins University:
cardiac surgery; brain injury; cerebral autoregulation processed this record on February 27, 2017