Tyrosine to threonine ratio was related to heart failure with reduced or mildly reduced ejection fraction

Abstract Aims We aim to explore the associations between serum tyrosine (Tyr) to threonine (Thr) ratio and chronic heart failure (HF) with reduced or mildly reduced ejection fraction (EF) (HFrEF or HFmrEF). Methods and results The study recruited 418 subjects (77.5% males, mean age 65.2 ± 12.5 years), including 318 HF subjects (HFrEF or HFmrEF) and 100 cardiovascular subjects without acute or chronic HF [including heart failure with preserved ejection fraction (HFpEF)] as controls. Serum levels of 21 kinds of amino acids (AAs) were measured by mass spectrometry. Logistic regression analysis was conducted to measuring the association between the AAs levels and the presence of HF. Event‐free survival was determined by Kaplan–Meier curves and differences in survival were assessed using log‐rank tests. Cox regression analysis was used to assess the prognostic value of AAs in HF. Receiver‐operating characteristic (ROC) curve was performed to further confirm regression analysis. Along with the control, HFmrEF, and HFrEF subjects, serum tyrosine (Tyr) gradually increased (64.43 ± 15.28 μmol/L vs. 71.79 ± 18.74 μmol/L vs. 77.32 ± 25.90 μmol/L, P