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.

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.

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