Exogenous KETOne Supplements in Patients Hospitalized for Acute Heart Failure

This study is testing whether ketone supplements (a type of energy source that the heart can use efficiently) can help patients who are hospitalized with acute heart failure — a sudden worsening of heart failure — by giving the weakened heart an alternative fuel source to improve its function. **You may be eligible if...** - You are 18 or older and admitted to the hospital specifically because of worsening heart failure - You have symptoms like severe shortness of breath at rest or with minimal activity, or extreme fatigue - Physical examination and lab results confirm your heart failure is worsening **You may NOT be eligible if...** - Your heart failure is a secondary issue (e.g., admitted primarily for another reason) - You are on dialysis or have very poor kidney function - You are pregnant - You have certain conditions that make the ketone supplement unsafe for you Talk to your doctor to see if this trial is right for you.