Trimethylamine N-oxide as a risk marker for ischemic stroke in patients with atrial fibrillation.

Trimethylamine N-oxide (TMAO) is an independent risk factor of cardiovascular disease. Our objective was to explore the relation between TMAO and ischemic stroke (IS) in patients with atrial fibrillation (AF). A total of 68 patients with AF with IS and 111 ones without IS were enrolled. The plasma levels of TMAO remarkably increased in IS-AF patients (8.25 ± 1.58 µM) compared with patients with AF (2.22 ± 0.09 µM, P < 0.01). The receiver operating characteristic analysis revealed that the best cutoff value of TMAO to predict IS in patients with AF was 3.53 µM with 75.0% sensitivity and 92.8% specificity (area under the curve: 0.917, 95% confidence intervals: 0.877-0.957). Univariate and multivariate logistic regression analysis showed that TMAO was an independent predictor in IS. The level of TMAO was correlated with the CHA2DS2-VASc score. In conclusion, TMAO was an independent predictor of IS, which could potentially refine stroke stratification in patients with AF.