Effects of Ketone Ester Consumption on Exercise Tolerance and Cardiac Function

Eligibility Criteria

• 1. Women who are pregnant, current breast-feeding, or have intention to become pregnant while in the trial
• 2. Known allergy or sensitivity to Gadolinium based contrast agents
• 3. Implanted pacemaker, cardioverter defibrillator, cardiac resynchronization therapy, left ventricular assist device
• 4. Other metallic implants/aneurysm clips that are contraindicated in MRI
• 5. Claustrophobia
• 6. History of severe kidney disease with estimated glomerular filtration rate (eGFR) \<30 ml/kg/1.73m2
• 7. Type I diabetes
• 8. History of diabetic ketoacidosis
• 9. Prescription use of sodium-glucose cotransporter-2 inhibitors (SGLT2i)
• 10. Prior diagnosis of oxygen dependent pulmonary disease
• 11. Body Mass Index (BMI) \< 25
• 12. Recent acute myocardial infarction or acute coronary syndrome (30 days)
• 13. Recent (within 30 days) or planned (within 30 days) cardiac revascularization.
• 14. History of un-revascularized left main coronary artery disease, severe un- revascularized triple vessel disease, coronary artery bypass graft surgery \< 30 days.
• 15. Left ventricular ejection fraction \< 50%
• 16. Uncontrolled systemic systolic/diastolic blood pressure (SBP/DBP) hypertension (SBP \>180 or DBP \>110 mmHg)
• 17. Severe stenotic or regurgitant valvular heart disease, expected to lead to surgery during the trial period.
• 18. Persistent atrial fibrillation.
• 19. History of uncontrolled or untreated ventricular arrhythmias
• 20. Cardiovascular diseases or treatments that increase the unpredictability of the subject's clinical course, independent of heart failure
• 21. Heart transplant or listing for heart transplant.
• 22. Cardiomyopathy based on infiltrative diseases (e.g. amyloidosis), accumulation diseases (e.g. haemochromatosis, Fabry disease), muscular dystrophies, cardiomyopathy with reversible causes (e.g. stress cardiomyopathy), hypertrophic obstructive cardiomyopathy or known pericardial constriction
• 23. Acute decompensated heart failure requiring intravenous diuretics, vasodilators, inotropic agents or mechanical support within 1 week of screening and during the screening period prior to randomization
• 24. Hemoglobin of \<9 g/dL at screening
• 25. Major surgery (major according to the investigator's assessment) performed within 90 days prior to screening, or major scheduled elective surgery (e.g. hip replacement) within 90 days after screening
• 26. Acute or chronic liver disease, defined by serum levels of transaminases or alkaline phosphatase more than three times the upper limit of normal at screening
• 27. Gastrointestinal surgery or gastrointestinal disorder that might interfere with supplement consumption. Prior bariatric surgery allowed if weight-stable for past 3 months.
• 28. Any documented active or suspected malignancy or history of malignancy within 2 years prior to screening, except appropriately treated basal cell carcinoma of the skin, in situ carcinoma of the uterine cervix, or low-risk prostate cancer (subjects with pre-treatment prostate-specific antigen levels of \<10 ng/mL, and biopsy Gleason scores of ≤6 and clinical stage T1c or T2a)
• 29. Presence of any disease other than heart failure that results in a life expectancy of \<1 year (in the opinion of the investigator)
• 30. History or recurrent severe hypokalemia, potassium \< 3.0 mg/dL.
• 31. Current enrolment in another investigational device or drug study or completion within \<30 days of a trial of another investigational device or drug study.
• 32. Chronic alcohol or drug abuse or any condition that, in the investigator's opinion, will make the subject unlikely to fulfil the trial requirements or complete the trial
• 33. Any other clinical condition that might jeopardize subject safety during participation in this trial or prevent the subject from adhering to the trial Protocol.
• 34. Unable or unwilling to follow guidelines of assigned supplement group.
• 35. Allergy to test article ingredients, or lactose intolerance
• 36. The subject cannot currently be on a low-carb diet plan. 30-day washout would be required.
• 37. Patient must have stable weight over the past 3 months (± 5% total body weight). If no weight was recorded in the past 3 months, will have 1 month lead in time for wash out.
• 38. Refusal to consent