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 who are undergoing cardiac surgery and have cerebral vascular disease or many other conditions. Such impairment could lead to brain injury because current practices of targeting low mean arterial blood pressure empirically (usually 50-70 mmHg) during cardiopulmonary bypass (CPB) may expose patients with impaired cerebral autoregulation to cerebral hypoperfusion. The hypothesis of this study is that targeting mean arterial pressure during CPB to a level above an individual's lower autoregulatory threshold reduces the risk for early neurologic complications from cardiac surgery or postoperative cognitive decline. Cerebral autoregulation will be monitored in real time by using software that continuously compares the relation between arterial blood pressure and low-frequency changes in transcranial Doppler measured cerebral blood flow velocity as well as cerebral oximetry measured with near infrared spectroscopy using methods we have validated. The primary endpoint of the study will be a composite outcome of clinical stroke, and/or new ischemic brain lesions detected with diffusion-weighted magnetic resonance (MR) imaging, and/or cognitive decline from baseline at 4 to 6 weeks after surgery. We will further assess for a relationship between blood pressure below the limits of autoregulation and delirium, an end-point associated with morbidity and mortality. Brain injury from cardiac surgery is an important source of operative mortality, prolonged hospitalization, increased healthcare expenditure, and impaired quality of life. Developing strategies to reduce the burden of this complication has wide public health implications and is within the mission of the NHLBI.

Public Health Relevance

Neurological complications from cardiac surgery are an important source of operative mortality, prolonged hospitalization, healthcare 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 techniques that could be widely used to reduce brain injury that results from inadequate brain blood flow during surgery.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
Project #
Application #
Study Section
Clinical and Integrative Cardiovascular Sciences Study Section (CICS)
Program Officer
Charette, Marc F
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Johns Hopkins University
Schools of Medicine
United States
Zip Code
Rivera-Lara, Lucia; Zorrilla-Vaca, Andres; Healy, Ryan J et al. (2018) Determining the Upper and Lower Limits of Cerebral Autoregulation With Cerebral Oximetry Autoregulation Curves: A Case Series. Crit Care Med 46:e473-e477
Easley, Ronald B; Marino, Bradley S; Jennings, Jacky et al. (2018) Impaired cerebral autoregulation and elevation in plasma glial fibrillary acidic protein level during cardiopulmonary bypass surgery for CHD. Cardiol Young 28:55-65
Adatia, Krishma; Geocadin, Romergryko G; Healy, Ryan et al. (2018) Effect of Body Temperature on Cerebral Autoregulation in Acutely Comatose Neurocritically Ill Patients. Crit Care Med 46:e733-e741
Healy, Ryan J; Zorrilla-Vaca, Andres; Ziai, Wendy et al. (2018) Glasgow Coma Scale Score Fluctuations are Inversely Associated With a NIRS-based Index of Cerebral Autoregulation in Acutely Comatose Patients. J Neurosurg Anesthesiol :
Hori, Daijiro; Nomura, Yohei; Ono, Masahiro et al. (2017) Optimal blood pressure during cardiopulmonary bypass defined by cerebral autoregulation monitoring. J Thorac Cardiovasc Surg 154:1590-1598.e2
Chang, Aaron J; Nomura, Yohei; Barodka, Viachaslau M et al. (2017) Validation of a Real-Time Minute-to-Minute Urine Output Monitor and the Feasibility of Its Clinical Use for Patients Undergoing Cardiac Surgery. Anesth Analg 125:1883-1886
Rivera-Lara, Lucia; Geocadin, Romergryko; Zorrilla-Vaca, Andres et al. (2017) Validation of Near-Infrared Spectroscopy for Monitoring Cerebral Autoregulation in Comatose Patients. Neurocrit Care 27:362-369
Magruder, J Trent; Crawford, Todd C; Harness, Herbert Lynn et al. (2017) A pilot goal-directed perfusion initiative is associated with less acute kidney injury after cardiac surgery. J Thorac Cardiovasc Surg 153:118-125.e1
Subramanian, Balachundhar; Nyman, Charles; Fritock, Maria et al. (2016) A Multicenter Pilot Study Assessing Regional Cerebral Oxygen Desaturation Frequency During Cardiopulmonary Bypass and Responsiveness to an Intervention Algorithm. Anesth Analg 122:1786-93
Hori, Daijiro; Ono, Masahiro; Adachi, Hideo et al. (2016) Effect of carotid revascularization on cerebral autoregulation in combined cardiac surgery†. Eur J Cardiothorac Surg 49:281-7

Showing the most recent 10 out of 55 publications