Trans-Valvular Unloading Reduces Anaerobic Glycolysis Before Reperfusion and Preserves Energy Substrate Utilization After Reperfusion in Models of Acute Myocardial Infarction

Abstract

<h3>Purpose</h3> The impact of mechanical left ventricular (LV) unloading before reperfusion on myocardial energetics in acute myocardial infarction (AMI) is unknown. We hypothesized that LV unloading reduces anaerobic glycolysis in models of ischemia reperfusion injury (IRI). <h3>Methods</h3> Myocardial ischemia was induced by percutaneous occlusion of the left anterior descending (LAD) artery for 90 minutes in adult swine. In Groups A and B, an additional 120 minutes of LAD occlusion was performed in the presence or absence of a trans-valvular pump (TVP). In Group C and D, post ischemia or LV unloading was followed by 120 minutes of reperfusion (Fig. 1A). Tissue from the infarct and non-infarct zones was analyzed using Ultrahigh Performance Liquid Chromatography-Tandem Mass Spectroscopy. <h3>Results</h3> In Groups A/B, LV unloading without reperfusion reduced lactate by 30±4% (p<0.006), glucose by 25±5% (p<0.02), and intermediates of glucose metabolism and ATP production consistent with decreased anaerobic glycolysis and reduced myocardial oxygen demand (Fig. 1B-C). In Groups C/D, LV unloading before reperfusion increased lactate and glucose levels by 30±5% and 75±30%, respectively (p<0.05), and increased intermediates of glucose oxidation and the tricarboxylic acid cycle. <h3>Conclusion</h3> We report for the first time that LV unloading during coronary occlusion reduces anaerobic glycolysis, energy substrate utilization and ATP production. These data support the need for further studies exploring the utility of LV unloading in AMI.