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

Introduction: Plasma concentrations of gut microbial metabolites are associated with cardiomyocyte viability and platelet reactivity. We hypothesized that increased concentrations of gut metabolites may predict major adverse cardiac and cerebrovascular events (MACCE) after acute myocardial infarction (AMI). Aim: The primary objective of this study was to evaluate the association between elevated plasma concentrations of gut metabolites and MACCE after AMI. Material and methods: We compared plasma concentrations of gut metabolites (trimethylamine-N-oxide (TMAO) and indoxyl sulphate (IS)) and platelet reactivity in 57 patients with AMI and 27 healthy controls. We assessed the predictive value of gut metabolites for MACCE (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 MACCE than in those who did not (p ≤ 0.015 for all). The concentration of TMAO was the only independent predictor of MACCE in a multivariate analysis (OR = 35.041, 95% CI: 1.269–967.307, p = 0.036). Patients with the concentration of TMAO and indoxyl sulphate above the cut-off value predictive of MACCE had higher platelet activity (p ≤ 0.149 for all). Conclusions: Increased plasma concentration of TMAO is an independent predictor of MACCE and may contribute to post-AMI cardiac dysfunction.