The PRE-OP ENERGY Trial

A Randomised Controlled Trial of a Pre-operative High Energy Diet for the Prevention of Organ Injury in Cardiac Surgery: The PRE-OP ENERGY Trial

The PRE-OP ENERGY Trial proposes to test the overarching hypothesis that a pre-surgery high energy diet will protect patients against organ damage during cardiac surgery with cardiopulmonary bypass.

Study Overview

• Status: Recruiting
• Conditions: Coronary Artery Disease; Cardiac Valve Disease; Organ Failure, Multiple
• Intervention / Treatment: Dietary supplement: High energy diet

Detailed Description

PRE-OP ENERGY is a single centre, unblinded, parallel group, randomised controlled trial of a pre-operative high energy diet, versus a control group receiving standard care.

The trial will test a number of specific hypotheses:

1. A pre-surgery high energy diet will protect against post-cardiac surgery organ failure by altering the pre-surgery cardiometabolic state, a process referred to as 'metabolic preconditioning'.
2. The effects of the trial intervention will not be attributable to changes in frailty, activity or baseline organ dysfunction.
3. The trial intervention will not result in long-term adverse changes in cardiometabolic status.
4. Metabolic preconditioning will confer protection against post-cardiac surgery kidney injury by increasing the expression of genes that promote renal tubular homeostasis.
5. Metabolic preconditioning will confer protection against post-cardiac surgery myocardial injury by increasing the expression of genes that promote myocardial mitochondrial homeostasis via effects on chromatin histone deacetylation.
6. Metabolic preconditioning will confer protection against post-cardiac surgery endothelial dysfunction by increasing the expression of genes that promote endothelial homeostasis.

• Study Type: Interventional
• Enrollment (Estimated): 116
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mustafa Zakkar, PhD; Phone Number: 3019 0116258; Email: mz207@le.ac.uk
• Study Contact Backup: Name: Hardeep Aujla; Phone Number: 2650 0116250; Email: ha200@le.ac.uk

Study Locations

• United Kingdom
  • Leicestershire
    • Leicester, Leicestershire, United Kingdom, LE3 9QP
      • Recruiting
      • University of Leicester

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

ALL of the following:

• Adult cardiac surgery patients (≥18 years) undergoing cardiac surgery (CABG, Valve, or CABG and Valve) with cardiopulmonary bypass.
• BMI<30
• Able, in the opinion of the investigator, and willing to give informed consent.
• Do not have diagnosed coeliac disease
• Able to understand English

Exclusion Criteria:

Any of the following:

• Urgent, emergency or salvage procedure
• Patients with end stage renal failure defined as an estimated Glomerular Filtration rate (eGFR) <15 mL/min/1.73 m2 calculated from the Modification of Diet in Renal Disease equation,1 or patients who are on long-term haemodialysis or have undergone renal transplantation.
• Patients with persistent or chronic atrial fibrillation.
• Patients with severe liver dysfunction; hepatitis, cirrhosis, jaundice.
• Women who are pregnant or who may become pregnant in the intraoperative period.
• Patients who are participating in another interventional clinical trial.
• Unable, in the opinion of the investigator, or unwilling to give informed consent.
• Have diagnosed coeliac disease
• Unable to understand English

Exclusion criteria for optional MRI research procedure:

• Permanent pacemaker or ICD
• Brain Aneurysm Clip
• Implanted neural stimulator
• Cochlear implant (specific implant must be checked that it is MR safe)
• Ocular foreign body (e.g. metal shavings) unless removed
• Other implanted medical devices: (e.g. Swan Ganz catheter)
• Insulin pump
• Retained metal shrapnel or bullet
• Claustrophobia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Group A: Control; Standard Care
Experimental: Group B: High energy diet; High energy diet for 8-12 weeks pre-surgery	Dietary supplement: High energy diet; An overfeeding regime of 135% required energy intake per day, set from baseline energy requirements consisting of high (saturated) fat snacks, added to the usual diet, supervised by a dietitian.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change of Serum Creatinine level	Measurement of Serum Creatinine level and expressed as umol/L.	Baseline, 0-6, 6-12, 24, 48, 72, and up to 96 hours post-operatively
Change of Serum Troponin I level	Measurement of Serum Troponin level and expressed as ng/L.	Baseline, 0-6, 6-12, 24, 48 and 72 hours post-operatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post-surgery organ injury: Sepsis-related Organ Failure	Sepsis-related Organ Failure Assessment (SOFA) Score. Range 0-3, 3 being the worse score	Baseline, pre-operatively, 0-6, 6-12, 24, 48, 72 and 96 hours post-operatively
Post-surgery organ injury: Kidney Injury (Urinary Biomarkers) - NGAL (Neutrophil gelatinase associated lipocalcin)	Urine samples will be analysed for biomarkers of renal injury. Measurement of NGAL level will be expressed as μg/L.	Baseline, 1 day pre-op, 6-12, 24 and 48 hours post-operatively
Post-surgery organ injury: Kidney Injury (Urinary Biomarkers) - microRNA (Neutrophil gelatinase associated lipocalcin)	Urine samples will be analysed for biomarkers of renal injury. Measurement of microRNA in urine samples will be represented by the frequency (%) of identified microRNA.	Baseline, 1 day pre-op, 6-12, 24 and 48 hours post-operatively
Post-surgery organ injury: Kidney Injury	Absolute change from baseline for serum creatinine	Daily for 5 days from Baseline
Post-surgery organ injury: Kidney Injury	Serum creatinine and eGFR in all patients using the Modification of Diet in Renal Disease equation. The following is the IDMS-traceable MDRD Study equation (for creatinine methods calibrated to an IDMS reference method) GFR (mL/min/1.73 m2) = 175 × (Scr)-1.154 × (Age)-0.203 × (0.742 if female) × (1.212 if African American) The equation does not require weight or height variables because the results are reported normalized to 1.73 m2 body surface area, which is an accepted average adult surface area.	At 6 weeks and then 3 months post-surgery
Post-surgery organ injury: Lung Injury using the Berlin ARDS Score	Using the Berlin ARDS score, the measurement of Arterial Alveolar oxygen ratio expressed in kPa/L.	Baseline, immediately pre-surgery, 0-6, 6-12, 24, 48, 72 and 96 hours post-operatively
Post-surgery organ injury: GI Tract injury (Biomarker) - AST (Aspartate Transaminase)	Measurement of AST levels in serum and expressed in IU/L. Acute liver injury will be defined as an acute derangement of three times the upper limit of normal.	Baseline, pre-assessment, pre-operatively, 0-6 and at 6-12, 24, 48, 72 and 96 hours post-operatively.
Post-surgery organ injury: GI Tract injury (Biomarker) - ALT (Alanine Transaminase)	Measurement of ALT levels in serum and expressed in IU/L. Acute liver injury will be defined as an acute derangement of three times the upper limit of normal.	Baseline, pre-assessment, pre-operatively, 0-6 and at 6-12, 24, 48, 72 and 96 hours post-operatively.
Post-surgery organ injury: GI Tract injury (Biomarker) - Bilirubin	Measurement of Bilirubin levels in serum and expressed in μmol/L. Acute liver injury will be defined as an acute derangement of three times the upper limit of normal.	Baseline, pre-assessment, pre-operatively, 0-6 and at 6-12, 24, 48, 72 and 96 hours post-operatively.
Post-surgery organ injury: GI Tract injury (Biomarker) - Alkaline Phosphatase	Measurement of Alkaline Phosphatase levels in serum and expressed in IU/L. Acute liver injury will be defined as an acute derangement of three times the upper limit of normal.	Baseline, pre-assessment, pre-operatively, 0-6 and at 6-12, 24, 48, 72 and 96 hours post-operatively.
Post-surgery organ injury: GI Tract injury (Biomarker) - Serum Amylase	Measurement of Amylase levels in serum and expressed in IU/L. Acute pancreatitis will be defined as a serum amylase concentration >1000 ng/ml.	Baseline, pre-assessment, pre-operatively, 0-6 and at 6-12, 24, 48, 72 and 96 hours post-operatively.
Assessment of resource use: Extubation	Time until extubation	Time (hours) measured from the start of surgery to extubation (up to 30 days)
Assessment of resource use: Intensive Care Unit	Length of stay in Intensive Care Unit. Number of hours between admission and discharge from the High Dependency Unit (HDU)	Time (hours) measured from the start of surgery to discharge from ICU (up to 30 days)
Assessment of resource use: Hospital Stay	Length of stay in hospital. Number of days between admission and discharge from the hospital	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Sepsis	Sepsis will be defined as suspected or documented infection and an acute change in total SOFA score ≥2 points consequent to the infection. For the purposes of the trial suspected or documented infection will be defined as the commencement of intravenous antibiotics. The rise in SOFA score will be assessed within 72 hours of the commencement of antibiotics. Range of SOFA is 0 to 3, 3 being the worse. For the purposes of the study suspected or documented infection will be defined as the commencement of intravenous antibiotics. The rise in SOFA score will be assessed within 72 hours of the commencement of antibiotics.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Peak lactate	Peak lactate within 24 hours of surgery and time to resolution of hyperlactataemia (arterial serum lactate >2.5 mmol/L) post peak.	Within 24 hours of surgery
Clinical events: Acute Lung Injury	Measurement of PaO2/FiO2 ratio and expressed in kPa/L.	Baseline, immediately pre-surgery, 0-6, 6-12, 24, 48, 72 and 96 hours post-operatively
Clinical events: Low cardiac output	Low cardiac output, defined as new intra-or postoperative intra-aortic balloon pump insertion or a cardiac index of <2.2 L/min/ m2 refractory to appropriate intravascular volume expansion after correction or attempted correction of any dysrhythmias, or the administration of the inotropes Dobutamine, Enoximone, Milrinone or Levosimendan.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Stroke	Stroke; diagnosed by brain imaging (CT or MRI), in association with new onset focal or generalized neurological deficit (defined as deficit in motor, sensory or co-ordination functions)	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Liver Injury - AST (Aspartate Transaminase)	Acute liver injury will be defined as an acute derangement of liver enzymes three times the upper limit of normal, or a serum amylase concentration >1000 ng/m.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Liver Injury - ALT (Alanine Transaminase)	Acute liver injury will be defined as an acute derangement of liver enzymes three times the upper limit of normal, or a serum amylase concentration >1000 ng/m.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Liver Injury - Bilirubin	Acute liver injury will be defined as an acute derangement of liver enzymes three times the upper limit of normal, or a serum amylase concentration >1000 ng/m.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Liver Injury - Alkaline Phosphatase	Acute liver injury will be defined as an acute derangement of liver enzymes three times the upper limit of normal, or a serum amylase concentration >1000 ng/m.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Liver Injury - Serum Amylase	Acute liver injury will be defined as an acute derangement of liver enzymes three times the upper limit of normal, or a serum amylase concentration >1000 ng/m.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Acute Intestinal Injury	Acute intestinal injury will be defined a radiological, operative or post-mortem evidence of gut ischaemia.	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Clinical events: Rate of mortality	Rate of mortality at 30-days and 1 year from the date of surgery	Within 30-days from surgery and at 1 year from surgery
Clinical events: A composite endpoint Organ Injury, Mortality and Sepsis	As above for description of organ injury, mortality and sepsis	Time (days) measured from the start of surgery to discharge from hospital (up to 90 days)
Bleeding and Transfusion	The total number of units of red cells and other blood components transfused during the operative period and post-operative hospital stay will be recorded	Blood loss at 6 hours post-operatively
Mechanism study: Mitochondrial function of microvessels from tissue biopsies	50-100 mg biopsies obtained from pedicled left internal mammary artery biopsies. The mitochondrial function will be measured through the Bioenergetic Health Index. The Bioenergetic Health Index (BHI) is calculated using the following formula: BHI=(ATP-linked×reserve capacity)/(proton leak×non-mitochondrial) - as described by Chacko et al. The expected range is 0-100.	At time of surgery
Mechanism study: microRNA isolation of microvessels from tissue biopsies	The findings will be represented by the frequency (%) of identified microRNA. 50-100 mg biopsies obtained from pedicled left internal mammary artery biopsies.	At time of surgery
Mechanism study: Chromatin Immunoprecipitation (ChIP) of microvessels from tissue biopsies	To identify protein binding sites that may help identify functional elements in the genome. Findings will be represented by the number (n) of binding sites. 50-100 mg biopsies obtained from pedicled left internal mammary artery biopsies.	At time of surgery
Mechanism study: Mitochondrial function measured in right atrium myocardium tissue biopsies	50-100 mg myocardial biopsies will be obtained from the right atrium at surgery. The mitochondrial function will be measured through the Bioenergetic Health Index. The Bioenergetic Health Index (BHI) is calculated using the following formula: BHI=(ATP-linked×reserve capacity)/(proton leak×non-mitochondrial) - as described by Chacko et al. The expected range is 0-100.	At time of surgery
Mechanism study: microRNA isolation in right atrium myocardium tissue biopsies	50-100 mg myocardial biopsies will be obtained from the right atrium at surgery. The findings will be represented by the frequency (%) of identified microRNA.	At time of surgery
Mechanism study: Chromatin Immunoprecipitation (ChIP) in right atrium myocardium tissue biopsies	50-100 mg myocardial biopsies will be obtained from the right atrium at surgery. To identify protein binding sites that may help identify functional elements in the genome. Findings will be represented by the number (n) of binding sites.	At time of surgery
Mechanism study: Mitochondrial function measured in adipose tissue biopsies	Adipose tissue collected from epicardial fat at time of surgery. The mitochondrial function will be measured through the Bioenergetic Health Index. The Bioenergetic Health Index (BHI) is calculated using the following formula: BHI=(ATP-linked×reserve capacity)/(proton leak×non-mitochondrial) - as described by Chacko et al. The expected range is 0-100.	At time of surgery
Mechanism study: microRNA isolation in adipose tissue biopsies	Adipose tissue collected from epicardial fat at time of surgery. The findings will be represented by the frequency (%) of identified microRNA.	At time of surgery
Mechanism study: Chromatin Immunoprecipitation (ChIP) in adipose tissue biopsies	Adipose tissue collected from epicardial fat at time of surgery. To identify protein binding sites that may help identify functional elements in the genome. Findings will be represented by the number (n) of binding sites.	At time of surgery
Mechanism study: Measurement of microvesicles in urine samples	Identification of microvesicles. The findings will be represented by the frequency (%) of each identified microvesicle.	Baseline,1 day before surgery, 6-12, 24 and 48 hours post-operatively.
Mechanism study: Measurement of microRNA in urine samples	The findings will be represented by the frequency (%) of identified microRNA.	Baseline,1 day before surgery, 6-12, 24 and 48 hours post-operatively.
Mechanism study: Measurement of histone acetylation in urine samples	The findings will be reported as acetylated H3 (ug/mg) over time (hours)	Baseline,1 day before surgery, 6-12, 24 and 48 hours post-operatively.
Mechanism study: Measurement of gene expression in urine samples	Whole genome sequencing will be achieved through ATAC sequencing. The identified genes will be characterised by average expression count over ATAC.	Baseline,1 day before surgery, 6-12, 24 and 48 hours post-operatively.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body Composition: Bone Density Scan (DEXA)	Assessments of muscle mass/sarcopenia (Appendicular lean mass taken from the DEXA scan)	Baseline, pre-assessment and 3 months post-surgery
Imaging Assessment of Cardiometabolic Status: Trans-Oesophageal Echo	Diastolic and systolic left ventricular function will be evaluated using intra-operative trans-oesophageal echo in all patients, as per standard care.	At time of surgery
Imaging Assessment (optional): Cardiac Magnetic Resonance Imaging - Cardiac Function	Assessment of cardiac function, by assessing ventricular function. This will be expressed as ejection fraction (%). Intravenous contrast will be administered via an indwelling venous catheter.	Baseline, pre-assessment and 3 months post-surgery
Imaging Assessment (optional): Cardiac Magnetic Resonance Imaging - Cardiac adiposity content	Assessment of cardiac adiposity content. A percentage of adipose tissue over total body mass will be calculated. Intravenous contrast will be administered via an indwelling venous catheter.	Baseline, pre-assessment and 3 months post-surgery
Imaging Assessment (optional): Cardiac Magnetic Resonance Imaging - Visceral adiposity content	Assessment of visceral adiposity content. A percentage of adipose tissue over total body mass will be calculated. Intravenous contrast will be administered via an indwelling venous catheter.	Baseline, pre-assessment and 3 months post-surgery
Fitness, Frailty and Muscle Strength: Six Minute Walk Test	Fitness will be assessed using the 6-minute walk test (6MWT) which is a standardized test that provides a valid assessment of functional performance. It provides a global assessment of exercise capacity and may better reflect daily activity than more traditional laboratory tests.	Baseline, pre-assessment and 3 months post-surgery
Fitness, Frailty and Muscle Strength: Hand Grip Test	Hand grip strength will be measured quantitatively by using a dynamometer. The result provides an objective index of general upper body strength and combined with appendicular lean mass (taken from the DEXA scan) could be used to define sarcopenia.	Baseline, pre-assessment and 3 months post-surgery
Fitness, Frailty and Muscle Strength: PRISMA-7 Questionnaire	Frailty assessment will be by use of the PRISMA-7 Questionnaire. The questions asked are: 1. Are you older than 85 years? 2. Are you male? 3. In general, do you have any health problems that require you to limit your activities? 4. Do you need someone to help you on a regular basis? 5. In general, do you have any health problems that require you to stay at home? 6. If you need help, can you count on someone close to you? 7. Do you regularly use a stick, walker or wheelchair to move about? The participant is asked to answer Yes or No to all 7 questions. SCORING: If the respondent had 3 or more "yes" answers, this indicates an increased risk of frailty and the need for further clinical review.	Baseline, pre-assessment and 3 months post-surgery
Activity Levels and Sleep: Accelerometer Assessments	Activity levels and sleep are measured by the use of seven day accelerometer assessments	Baseline, pre-assessment and 3 months post-surgery
Comorbidity and Inflammation - CRP (C-Reactive-Protein) assay (Abcam)	Pre-existing inflammation, renal impairment and heart failure will be assessed using highly sensitive CRP assay, NT-proBNP (both Abcam), and estimated Glomerular Filtration Rate (from serum creatinine). The acceptable range for CRP values using the abcam kit is 34.29 - 25,000 pg/mL. For values above 25ng/mL, the samples will be diluted and re-assayed. Samples < 34.29 pg/mL will be re-assayed at higher concentration when possible; otherwise the concentrations will be accepted if higher than assay detection limit (2 pg/L). For samples <2pg/mL a no-expression value will be assigned.	Baseline, pre-assessment and 3 months post-surgery
Comorbidity and Inflammation - NT-proBNP (Abcam)	Pre-existing inflammation, renal impairment and heart failure will be assessed using highly sensitive CRP assay, NT-proBNP (both Abcam), and estimated Glomerular Filtration Rate (from serum creatinine). The acceptable range for NT-proBNP values using the abcam kit is 0.14 - 100 ng/mL. For values above 100ng/mL, the samples will be diluted and re-assayed. Samples < 0.14 ng/mL will be re-assayed at higher concentration when possible; otherwise a no-expression value will be assigned.	Baseline, pre-assessment and 3 months post-surgery
Comorbidity and Inflammation - estimated Glomerular Filtration Rate	Pre-existing inflammation, renal impairment and heart failure will be assessed using highly sensitive CRP assay, NT-proBNP (both Abcam), and estimated Glomerular Filtration Rate (from serum creatinine). Formula for GFR (mL/min/1.73 m2) = 175 × (Scr)-1.154 × (Age)-0.203 × (0.742 if female) × (1.212 if African American) The equation does not require weight or height variables because the results are reported normalized to 1.73 m2 body surface area, which is an accepted average adult surface area.	Baseline, pre-assessment and 3 months post-surgery
Endothelial function: Blood samples	Markers of endothelial activation will be measured in blood samples using flow cytometry.	Baseline, 6-12 and 48 hours post-surgery
Endothelial function: Reactive Hyperaemia Peripheral Arterial Tonometry (RH-PAT)	Regional endothelial dysfunction will be measured as the reactive hyperaemia peripheral arterial tonometry (RH-PAT) index using the Endo-PAT 2000 (Itamar Medical Ltd., Caesarea, Israel)	1 day before surgery and 24 hours post-surgery
Endothelial function: Global endothelial dysfunction	Global endothelial dysfunction will also be measured indirectly as the measured time to resolution of oxygen debt defined as the period of time from the end of surgery until the measured serum arterial lactate level falls below 2.5 mmol/L.	End of surgery, 0-6, 6-12, 24, 48, 72 and 96 hours post-operatively (until the timepoint serum arterial lactate falls below 2.5 mmol/L)

Collaborators and Investigators

• Sponsor: University of Leicester
• Investigators: Study Chair: Gavin J Murphy, MD, BHF Professor of Cardiac Surgery, University of Leicester; Principal Investigator: Mustafa Zakkar, PhD, Associate Professor, University of Leicester

Study record dates

Study Major Dates

• Study Start (Actual): May 7, 2019
• Primary Completion (Estimated): April 1, 2024
• Study Completion (Estimated): October 7, 2024

Study Registration Dates

• First Submitted: May 20, 2019
• First Submitted That Met QC Criteria: July 10, 2019
• First Posted (Actual): July 11, 2019

Study Record Updates

• Last Update Posted (Actual): November 7, 2023
• Last Update Submitted That Met QC Criteria: November 6, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Myocardial Ischemia; Heart Diseases; Cardiovascular Diseases; Vascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Shock; Coronary Disease; Coronary Artery Disease; Heart Valve Diseases; Multiple Organ Failure
• Other Study ID Numbers: 0668; 246009 (Registry Identifier: IRAS); 18/EM/0254 (Other Identifier: REC East Midlands - Leics Central)

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: No