Plasma concentration of TMAO is an independent predictor of adverse outcomes in patients after acute myocardial infarction

Background: Plasma concentrations of gut microbial metabolites are associated with cardiomyocytes viability and platelet reactivity. We hypothesised that increased concentrations of gut metabolites may predict major adverse cardiovascular events (MACE) after acute myocardial infarction (AMI). Methods: : We compared plasma concentrations of gut metabolites (trimethylamine-N-oxide, TMAO and indoxyl sulphate, IS) and platelet reactivity in 60 patients with AMI and 27 healthy controls. We assessed the predictive value of gut metabolites for MACE (stroke, recurrent AMI, death) over a median of 3.5-years. Results: : The concentrations of TMAO and IS did not differ between AMI patients and controls. The concentrations of TMAO and IS were higher in patients who developed MACE, compared to those who did not (p≤0.015 for all). The concentration of TMAO was the only independent predictor of MACE in a multivariate analysis (OR 35.041, CI 1.269-967.307, p=0.036). Patients with the concentration of TMAO and indoxyl sulphate above the cut-off value predictive of MACE had higher platelet activity (p≤0.149 for all). Conclusions: : Increased plasma concentration of TMAO is the independent predictor of MACE and may contribute to post-AMI cardiac dysfunction.