Increased serum 2-oxoglutarate associated with high myocardial energy expenditure and poor prognosis in chronic heart failure patients

• Levels of serum 2-oxoglutarate were elevated in patients with CHF.
• 2-Oxoglutarate levels were closely associated with the elevation of MEE.
• Serum 2-oxoglutarate could be a potential biomarker of MEE in CHF patients.
• Levels of 2-oxoglutarate were correlated with adverse short-term events in CHF.

Myocardial energy expenditure (MEE) and 2-oxoglutarate are elevated in chronic heart failure (CHF) patients compared with healthy controls. To explore whether 2-oxoglutarate could reflect the levels of MEE and predict the prognosis of CHF, 219 CHF patients and 66 healthy controls were enrolled. 2-Oxoglutarate was assayed with Liquid Chromatography–Mass Spectrometry/Mass Spectrometry (LC/MS/MS). CHF patients were divided into 4 groups according to interquartile range of MEE and followed for death or recurrent hospital admission due to CHF for the mean follow-up time 6.64 ± 0.16 months. 2-Oxoglutarate was increased in CHF patients compared with controls (P < 0.01) and correlated with estimated glomerular filtration rate (r = 0.142, P = 0.036), age (r = − 0.269, P < 0.01) and MEE levels (r = 0.307, P < 0.01) in a multiple linear correlation analysis in CHF patients. Furthermore, 2-oxoglutarate (OR = 3.470, 95% CI = 1.557 to 7.730, P = 0.002), N-terminal pro-B-type natriuretic peptide (OR = 4.013, 95% CI = 1.553 to 10.365, P = 0.004), age (OR = 1.611, 95% CI = 1.136 to 2.283, P = 0.007) and left ventricular ejection fraction (OR = 7.272, 95% CI = 3.110 to 17.000, P < 0.001) were independently associated with MEE on multiple logistic regression analysis. Kaplan–Meier event curves showed that high 2-oxoglutarate levels were associated with adverse outcomes (Log Rank, Chi2 = 4.026, P = 0.045). This study showed that serum 2-oxoglutarate is associated with MEE levels, which can be used as potential biomarkers for MEE, and it can reflect the clinical severity and short-term outcome of CHF.