Prolonged Nasogastric Administration of Ketones in Decompensated Heart Failure

Adult patients with left ventricular ejection fraction (LVEF) \<35% admitted to the intensive care unit for acutely decompensated heart failure with low cardiac output syndrome or cardiogenic shock will receive a continuous infusion of D-3-hydroxybutyrate (3-OHB) monoester via a nasogastric tube for 36 hours. The infusion rate will be iteratively adjusted to achieve an arterial blood concentration of 3-OHB of 2-3.5 mmol/L. Arterial blood concentrations of 3-OHB will be measured every 1-3 hours using point-of-care testing. The primary endpoint will be the proportion of time within the target concentration range. Secondary safety endpoints will include worsening of liver function not attributable to hemodynamic deterioration, occurrence of cardiac arrhythmias, and gastrointestinal tolerance of the infusion.