Plasma trimethylamine N-oxide levels and cardiometabolic risk factors in patients with acute myocardial infarction undergoing invasive treatment

Abstract Background Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite, has been implicated in atherosclerotic plaque progression and adverse cardiovascular outcomes through mechanisms involving endothelial dysfunction, oxidative stress, and platelet activation. Elevated TMAO concentrations have been associated with increased cardiometabolic risk, but its relationship with conventional risk factors in acute myocardial infarction (AMI) populations remains insufficiently defined. Purpose The aim of this study was to assess plasma TMAO levels in patients admitted with AMI undergoing invasive treatment and to examine their association with classical cardiovascular risk factors. Methods In this cross-sectional study, 76 consecutive patients admitted with AMI to a tertiary care centre and treated invasively were analyzed. Plasma TMAO concentrations were determined using high-performance liquid chromatography. Demographic and clinical variables, including age, sex, body mass index (BMI), smoking history, hypertension (HA), diabetes mellitus type 2 (DM2), multivalve disease, and STEMI presentation, were collected prospectively. TMAO levels were compared between subgroups defined by cardiovascular risk factors. Results The mean age of the study cohort was 65.6 ± 10.1 years, and 21 patients (27.6%) were women. Hypertension was present in 48 patients (63.2%), DM2 in 25 (32.9%), nicotine use in 31 (40.8%), and multivalve disease in 33 (43.4%). Mean BMI was 27.9 ± 4.4 kg/m². The mean plasma TMAO concentration was 376.6 ± 280.7 nmol/L (range 68.9–1575.8 nmol/L). TMAO levels were similar between men and women (375.9 vs. 378.1 nmol/L; p = 0.978). Patients with hypertension had numerically higher TMAO levels than those without (402.4 vs. 331.2 nmol/L), but the difference was not statistically significant (p = 0.315). Patients with DM2 demonstrated significantly higher TMAO concentrations compared with non-diabetic individuals (494.0 vs. 314.0 nmol/L; p = 0.010). No significant differences in TMAO levels were observed according to smoking status (396.6 vs. 350.6 nmol/L; p = 0.503), presence of multivalve disease (348.0 vs. 411.6 nmol/L; p = 0.353), or STEMI presentation (434.8 vs. 336.8 nmol/L; p = 0.156). Conclusions In patients admitted with acute myocardial infarction undergoing invasive treatment, plasma TMAO levels were significantly higher in individuals with type 2 diabetes mellitus, but not in relation to hypertension, smoking, or other classical cardiovascular risk factors. These findings suggest that TMAO may reflect a distinct cardiometabolic risk phenotype rather than traditional atherosclerotic burden. Further prospective studies are warranted to define the role of TMAO as a potential biomarker for risk stratification and preventive strategies in acute coronary syndromes.For image description, please refer to the figure legend and surrounding text.