Hemodynamic effects of lactate infusion in chronic heart failure patients

Abstract Background Elevated lactate levels are associated with adverse outcomes in patients with acute heart failure and have often been regarded as toxic. However, in experimental studies, lactate is now recognized as a key energy source and signaling molecule. In patients with heart failure, its cardiovascular effects remain unclear. Purpose To investigate the hemodynamic effects of lactate infusion in patients with heart failure. Methods In a double-blind, randomized cross-over design, 12 patients with chronic heart failure with reduced ejection fraction received, in random order, a three-hour infusion of sodium lactate and isotonic sodium chloride. Patients were assessed with pulmonary artery catheterization, arterial blood samples, and echocardiography every hour. Data were analyzed with a linear mixed-effects model. Results Compared with placebo, lactate infusion significantly increased cardiac output (6.6 ± 1.1 vs. 5.7 ± 1.0 L/min, p 0.001) and heart rate (72 ± 11 vs. 66 ± 7 min⁻¹, p 0.001). Systemic vascular resistance was significantly reduced during lactate infusion (-1.3 WU, p 0.001), whereas mean arterial pressure, central venous pressure, pulmonary capillary wedge pressure, mean pulmonary arterial pressure, and pulmonary vascular resistance did not differ between arms. Analysis of variance revealed a significant interaction between treatment and time for cardiac output (p = 0.02) and pulmonary capillary wedge pressure (p = 0.002), indicating that the response to lactate infusion varied across time points. Conclusion Lactate infusion increased cardiac output and heart rate and reduced systemic vascular resistance. The time-dependent effects on cardiac output and pulmonary capillary wedge pressure suggest that lactate infusion exerts a dynamic influence on cardiovascular function. Lactate may be a potentially beneficial modulator of cardiac performance in patients with heart failure.