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

This study tests whether taking a special oral ketone supplement helps people who have both heart failure with reduced pumping ability (HFrEF) and diabetes. Researchers will use MRI scans and other tests to see how ketones affect heart and metabolic function. **You may be eligible if...** - You are between 18 and 80 years old - You have an established diagnosis of heart failure (confirmed by imaging in the last 6 months) and are on stable heart failure medications - You have a BMI between 23 and 38 - Your blood sugar (HbA1c) is between 6.0% and 10.0% - Your blood pressure is below 145/85 mmHg and your kidney function is adequate **You may NOT be eligible if...** - You are currently taking SGLT2 inhibitors (a type of diabetes medication) - You have had a cardiovascular event (heart attack, etc.) in the last 3 months - You are pregnant, breastfeeding, or planning to become pregnant - You have a history of most cancers (some exceptions apply) - You have significant organ problems that would interfere with completing the study Talk to your doctor to see if this trial is right for you.