Trimethylamine N-oxide as a Novel Biomarker for Left Ventricular Diastolic Dysfunction and Functional Remodeling in ST-Elevation Myocardial Infarction Patients

Abstract Background Over the last three decades, the mortality from ST-elevation myocardial infarction (STEMI) has halved. However, the incidence of heart failure or persistent angina remains high after STEMI, and the post-STEMI left ventricular (LV) systolic and diastolic function remains unpredictable. Thus, there is an unmet need to identify patients at risk of LV diastolic dysfunction or adverse remodeling. Purpose This study aims to investigate the potential of Trimethylamine N-oxide (TMAO), a gut microbiota-derived metabolite associated with heart failure, and atherosclerosis, as a biomarker for adverse LV remodeling and diastolic dysfunction following STEMI. Methods In this prospective, observational cohort study, 210 STEMI patients with multivessel coronary artery disease (CAD) were enrolled after primary PCI. At 3 months follow-up, all patients underwent complete revascularization with FFR-guided PCI. Plasma TMAO, C-reactive protein (CRP), and brain natriuretic peptide (BNP) levels at 3 months follow-up and peak troponin level at primary PCI were collected. Echocardiographies were performed within 24 hours of STEMI and at 12-month follow-ups. Diastolic dysfunction was defined according to the ASE 2016 guidelines.(1) Functional LV remodeling (FLVR) was categorized into 4 categories according to Chimed et al.(2) Receiver operating characteristic (ROC) curve analysis, including the Delong test and Youden index, was performed to compare the biomarkers' diagnostic value and determine the optimal cutoffs for predicting diastolic dysfunction and FLVR, respectively. Results Of the 210 patients enrolled, 85 (40.48%) were female, with a median age of 65 years [interquartile range (IQR): 58.00, 76.00] and a median body mass index (BMI) of 27.39 kg/m² (IQR: [24.56, 30.69]). The area under the ROC curve for predicting post-PCI LV diastolic dysfunction ≥ grade II was 0.72 (95% CI 0.63–0.81; p<0.001) for TMAO (Figure 1). The optimal TMAO cutoff value of 3.80 yielded a sensitivity of 0.75 (95% CI 0.63–0.86) and a specificity of 0.82 (95% CI 0.76–0.88). For FLVR grade 3 or 4, the area under the ROC curve was 0.62 (95% CI 0.50–0.74) and 0.72 (95% CI 0.62 -0.83) for TMAO and BNP, respectively (Figure 2), but the AUC was not significantly different (p= 0.191). In multivariable logistic regression analysis, TMAO was independently associated with FLVR grade 3 or 4 (OR 1.18, 95% CI 1.00-1.38, p = 0.046) and diastolic dysfunction ≥grade 2 (OR 1.30, 95% CI 1.12-1.50, p < 0.001). Conclusion The novel parameter of TMAO is a useful predictor for LV diastolic dysfunction after STEMI. TMAO is independently associated with an increased risk of LV diastolic dysfunction and worse FLVR. These results suggest that monitoring plasma TMAO levels could be an effective and cost-efficient strategy for monitoring patients with an elevated risk of LV diastolic dysfunction or adverse LV remodeling.Figure 1Figure 2