The ketone body 3-hydroxybutyrate increases cardiac output and cardiac contractility in a porcine model of cardiogenic shock: a randomized, blinded, crossover trial

Cardiogenic shock (CS) is characterized by reduced cardiac output (CO), reduced end-organ perfusion, and high mortality. Medical therapies have failed to improve survival. The ketone body 3-hydroxybutyrate (3-OHB) enhances cardiac function in heart failure and CS. We aimed to elucidate the cardiovascular and cardiometabolic effects of 3-OHB treatment during CS. In a randomized, assessor-blinded crossover design, we studied 16 female pigs (60 kg, 5 months of age). CS was induced by left main coronary artery microsphere injections. Predefined criteria for CS were a 30% reduction in CO or mixed venous saturation (SvO₂). Intravenous 3-OHB infusion and a matching control solution were administered for 120 min in random order. Hemodynamic measurements were obtained by pulmonary artery catheterization and a left ventricular (LV) pressure-volume catheter. Myocardial mitochondrial function was assessed using high resolution respirometry. During CS, infusion with 3-OHB increased CO by 0.9 L/min (95%CI 0.4-1.3 L/min) compared with control infusion. SvO₂ (P = 0.026) and heart rate (P < 0.001) increased. Stroke volume (P = 0.6) was not altered. LV contractile function as determined by LV end-systolic elastance improved during 3-OHB infusion compared with control infusion (P = 0.004). Systemic and pulmonary vascular resistance decreased, and diuresis increased. LV mitochondrial function was higher after 3-OHB infusion compared with control. We conclude that 3-OHB infusion enhances cardiac function by increasing contractility and reducing vascular resistance, while also preserving myocardial mitochondrial respiratory function in a large animal model of ischemic CS. These novel findings support the therapeutic potential of exogenous ketone supplementation in CS management.