Acute and Chronic Effects of Oral Ketones in Subjects With HFrEF and Diabetes

Inclusion Criteria:

* Subjects must be on a stable dose of guideline-directed medications for Heart Failure (HF).
* Patients will have an established diagnosis of HF before the screening visit, documented by an acceptable imaging modality in the last 6 months.
* Age = 18-80 y
* Body Mass Index (BMI) =23-38 kg/m2
* Glycated hemoglobin (HbA1c) = 6.0-10.0%
* Blood Pressure (BP) \< 145/85 mmHg
* Estimated Glomerular Filtration Rate (eGFR) \> 30 ml/min•1.73 m2
* For women of child-bearing age (WOCBA) willingness to use contraception, if applicable.

Exclusion Criteria:

* Patients treated with Sodium-Glucose Transport Protein (SGLT2i's) or medications that may impair heart function or acutely worsen glycemic control will be excluded.
* Pregnancy, lactation, or plans to become pregnant. A negative pregnancy test will be performed before each Magnetic resonance imaging (MRI) study to assess current status.
* Allergy/sensitivity to study drugs or their ingredients.
* Current drug or alcohol use or dependence that, in the opinion of the site investigator, would interfere with adherence to study requirements.
* Inability or unwillingness of individual or legal guardian/representative to give written informed consent.
* Subjects with a history of cancer (except basal or squamous cell cancer that has been resolved/remission for 5 years)
* Cardiovascular event within the last 3 months
* Major organ or metabolic diseases, or physical limitations that will not allow the subject to complete the study.