Elevated serum Trimethylamine-N-oxide predicts the risk of arteriovenous fistula dysfunction in patients on maintenance hemodialysis

Introduction: Arteriovenous fistula (AVF) dysfunction causes significant morbidity in maintenance hemodialysis (MHD) patients. This study investigated the association between the gut-derived uremic toxin Trimethylamine-N-oxide (TMAO) and AVF failure risk. Methods: Baseline serum TMAO was measured in 164 MHD patients with functional AVFs. The primary endpoint over a 24-month follow-up was the first AVF dysfunction event. We utilized optimal cut-point determination, Kaplan-Meier survival analysis, and Cox proportional hazards models. Results: Over 24 months, 43 patients (26.2%) experienced AVF dysfunction. The optimal TMAO cut-point was 278.74 μmol/L. High TMAO (>278.74 μmol/L) correlated with significantly earlier AVF dysfunction (log-rank p = 0.030) and remained an independent predictor of AVF failure after multivariable adjustment (HR, 2.07; 95% CI, 1.04–4.13; p = 0.035). Discussion: Elevated baseline TMAO is an independent risk factor for AVF dysfunction. Serum TMAO >278.74 μmol/L serves as a novel prognostic risk stratifier identifying MHD patients at high risk for vascular access failure.