In view of the reports correlating heart failure (HF) outcomes with trimethylamine N-oxide (TMAO), which is a gut-related metabolite and the final product of a complex metabolic pathway (ie, choline/carnitine), researchers here investigate a panel of metabolites involved in the TMAO-choline/carnitine metabolic pathway for their correlations with outcome in acute HF patients. TMAO, trimethyllysine, L-carnitine, acetyl-L-carnitine, γ-butyrobetaine, crotonobetaine, trimethylamine, betaine aldehyde, choline, and betaine were examined in 806 plasma samples from acute HF patients using a developed liquid chromatography-tandem mass spectrometry method. Findings support the correlations of carnitine-related metabolites with adverse outcomes in acute HF, in particular L-carnitine and acetyl-L-carnitine for short-term outcomes, and TMAO for long-term outcomes Source