C86 ASSOCIATION OF PLASMA TMAO VALUES WITH ANOTHER ISCHEMIC EVENT DURING LONG–TERM FOLLOW–UP IN PATIENTS WITH MYOCARDIAL INFARCTION

Abstract

Abstract Background Elevated plasma trimethylamine N–oxide (TMAO) levels, a metabolite derived from the intestinal microbiota, are closely related to atherosclerosis due to its involvement in increased inflammation, oxidative stress and cholesterol reverse transport. Objectives Blood samples were collected at admission from 81 patients who survived acute myocardial infarction (AMI) and from 10 healthy individuals. TMAO concentrations were measured by means of liquid chromatography–tandem mass spectrometry with an aim to evaluate the predictive value of this biomarker in terms of another major event during long–term follow–up. Results Patients with AMI have significantly higher median plasma TMAO concentration compared to healthy individuals (respectively, 1.62 (1.37 – 2.25) µM vs 0.55 (0.35 – 0.74) µM, p < 0.0001). Considering only patients with AMI, TMAO values positively correlated with pro–inflammatory markers CRP and TNF–α. In addition, TMAO positively correlated with creatinine and negatively correlated with GFR. Moreover, we noted the trend of higher TMAO values among patients with diabetes mellitus compared to patients without (1.68 (1.44 – 5.43) µM vs 1.59 (1.33 – 2.099) µM, p=0.065). During a median follow–up of 61.74 (59.34 – 64.24) months, 10 patients suffered another infarction. Those individuals had significantly higher TMAO values compared to subjects without another ischemic event (respectively, 2.29 (1.60 – 6.49) µM vs 1.60 (1.34 – 2.09) µM, p = 0.026). Kaplan–Meier analysis confirmed that elevated values of TMAO were associated with the risk of another infarction (p=0.029), whereas multivariate Cox regression analysis did not demonstrate the prognostic value of TMAO towards re–infarction probably due to the small cohort. Conclusions Higher plasma TMAO values at admission in patients with AMI are associated with re–infarction at long–term follow–up.