In this study the investigator will randomize 273 subjects to deep (\<20°C), low (20.1°C-24°C), or moderate (24.1°C-28°C) hypothermia during aortic arch surgery with circulatory arrest. The primary purpose of this study is to determine the effect of deep vs low vs moderate hypothermia on neurocognitive function, brain functional connectivity, and leukocyte SUMOylation patterns after surgical circulatory arrest in participants.
Purpose of the Study: Determine the effect of deep vs low vs moderate hypothermia on neurocognitive function, brain functional connectivity, and leukocyte SUMOylation patterns after surgical circulatory arrest. Hypothesis: Deep hypothermia is superior to moderate hypothermia in reducing postoperative cognitive decline and preserving brain functional connectivity and that low hypothermia is non-inferior to deep hypothermia. Design and Procedures: 273 informed and consenting patients who are scheduled for elective proximal aortic reconstructive surgery (ascending aorta + aortic valve or root) with concomitant proximal hemi- or total arch replacement via median sternotomy will be randomized to deep (\<20°C), low (20.1°C-24°C), or moderate (24.1°C-28°C) hypothermia during circulatory arrest. Cognitive testing using a standard battery will occur preoperatively (baseline), at 4 weeks, and at 1 year after surgery. Neuroimaging procedures before surgery, and at 4 weeks and 1 year after surgery will consist of high-resolution anatomic, resting-state fMRI (rs-fMRI) and magnetic resonance spectroscopy (MRS) sequences. To characterize leukocyte activation, whole blood will be drawn at 5 time points: at baseline (prior to surgery), before circulatory arrest, 10 minutes after reperfusion, 10 minutes after CPB, and 4 hours after CPB.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
TRIPLE
Enrollment
273
Routinely used cardiopulmonary bypass machine (standard of care) will be used to initiate circulatory arrest
Emory Saint Joseph's Hospital
Atlanta, Georgia, United States
Duke University Health System
Durham, North Carolina, United States
Penn Presbyterian Medical Center
Philadelphia, Pennsylvania, United States
Baylor Scott & White Research Institute
Plano, Texas, United States
Change in short-term cognition as measured by continuous cognitive score
To characterize cognitive function over time while minimizing potential redundancy in the cognitive measures, a factor analysis will be performed on the cognitive test scores from baseline. A continuous change score will be calculated by subtracting the baseline cognitive index (the mean of the domain scores from factor analysis) from the follow-up cognitive index at 4 weeks.
Time frame: From baseline to 4 weeks post-operatively
Change in SUMO 2/3 levels
Time frame: Pre-incision, before circulatory arrest, 10 minutes after reperfusion, 10 minutes after cardiopulmonary bypass, 4 hrs after cardiopulmonary bypass
Change in long-term cognition as measured by continuous cognitive score
To characterize cognitive function over time while minimizing potential redundancy in the cognitive measures, a factor analysis will be performed on the cognitive test scores from baseline. A continuous change score will be calculated by subtracting the baseline cognitive index (the mean of the domain scores from factor analysis) from the follow-up cognitive index at 1 year.
Time frame: From baseline to 1 year post-operatively
Incidence of delirium
Confusion Assessment Method (CAM)
Time frame: Up to post-operative day 3
Change in neurological function as measured by NIHSS
Time frame: Assessed at baseline, post-op day 4, 4 weeks
Change in neuronal metabolism
Magnetic resonance spectra (metabolic peaks) of myoinositol, creatine, choline and N-acetyl aspartate
Time frame: From baseline to 4 weeks
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Change in resting-state functional connectivity
For the rs-fMRI data, the analyses of primary interest will be the spontaneous, low-frequency fluctuations in the blood oxygen level dependent (BOLD) data of the Default Mode, Salience, and Executive Control Networks.
Time frame: From baseline to 4 weeks post-operatively
Change in Duke Activity Status Index score
Time frame: From baseline to 4 weeks postoperatively
Change in depression score
Measured by the Center for Epidemiological Studies Depression Scale (CES-D).
Time frame: From baseline to 4 weeks postoperatively
Change in anxiety score
Measured by State Trait Anxiety Inventory (STA-I).
Time frame: From baseline to 4 weeks postoperatively
Change in SF-36 score
Time frame: From baseline to 1 year postoperatively
Change in employment status
Time frame: From baseline to 1 year postoperatively