Xu, Yizhou

Introduction: Cardiac remodeling in heart failure (HF) is associated with conduction abnormalities and dyssynchrony which results in poorly coordinated contractions precipitating metabolic heterogeneity and energetic inefficiency. Cardiac resynchronization therapy (CRT) improves HF symptoms, ventricular function and overall survival. The aim of this study was to determine the changes in metabolomic profiles and substrate utilization after CRT. Methods: 18 patients with advanced HF and 7 healthy controls were included in this study. Blood samples were collected from peripheral vein, femoral artery (FA) and coronary sinus (CS) before and 10-min after CRT. Metabolomic profiling of plasma samples were performed using GC/MS and 1 H NMR spectroscopy. Partial Least Squares Discriminant Analysis (PLS-DA) score plots and regression coefficients were used to examine metabolomic profiles. Results: HF patients have altered plasma metabolomic profile (Fig. A) with distinct panel of metabolites including free fatty acids (FFA), glycerol, 2-hydroxybutyrate, glycine, succinate and uric acid important in group classification compared to controls. Increased release of fumarate and glycerol-3-phosphate from myocardium in HF indicate mitochondrial and substrate shuttle dysfunction. Immediately after CRT, transcardiac metabolomic profile of plasma from CS shifted to a different state with increased myocardial uptake and metabolism of FFA and decreased release of creatinine indicating improved energetic conditions (Fig. B). Conclusion: Metabolomic profiling indicates that CRT improves myocardial substrate metabolism and utilization in patients with advanced HF.