BACKGROUND Ketone bodies, especially β-hydroxybutyrate, have shown the potential to improve hemodynamic outcomes such as cardiac output (CO) and left ventricular ejection fraction (LVEF) in patients with heart failure (HF). However, the overall effectiveness of ketone body supplementation in this population remains uncertain. Therefore, we conducted this systematic review and meta-analysis to evaluate the impact of ketone body supplementation on cardiac and hemodynamic parameters in patients wit