Trimethylamine N-Oxide is Associated with Heart Failure Risk in Patients with Preserved Ejection Fraction.

BACKGROUND Trimethylamine N-oxide (TMAO) has been considered to be an independent risk factor of heart failure (HF). OBJECTIVES To further determine the plasma levels of TMAO in patients who have HF with preserved ejection fraction (HFpEF), and to analyze the relationship between TMAO and HFpEF risk. METHODS A total of 57 control participants and 61 patients with HFpEF were recruited. We measured and analyzed plasma levels of TMAO and performed biochemical examination of all patients. RESULTS The mean (SD) plasma levels of TMAO in patients with HFpEF (6.84 [1.12] μmol/L) were significantly higher than in controls (1.63 [0.08] μmol/L; P <.01). The area under the curve (AUC) of TMAO and N-terminal pro b-type natriuretic peptide (NT-proBNP) was 0.817 and 0.924, respectively, which were determined by receiver operating characteristic (ROC) analysis. TMAO was an independent risk factor in patients with HFpEF, as revealed by univariate and multivariate logistic regression analysis. The level of TMAO was correlated with blood urea nitrogen (BUN), creatinine, and NT-proBNP. CONCLUSIONS TMAO level was highly associated with HFpEF risk.