Asymmetric dimethylarginine predicts left atrial appendage thrombus in patients with non-valvular atrial fibrillation

Introduction: Atrial fibrillation (AF) is associated with increased thrombo-embolic events, with thrombi most frequently located in the left atrial appendage (LAA). Asymmetric dimethylarginine (ADMA), a potent endogenous inhibitor of nitric oxide synthase, is elevated in subjects with AF. We investigated the relationship between ADMA and risk of LAA thrombus in patients with non-valvular AF. Methods and results: A total of 223 consecutive patients with non-valvular AF were enrolled (63 +/- 10 years, 65% male). LAA thrombus was detected in 27 subjects by transesophageal echocardiography. Serum ADMA was significantly increased (2.5 +/- 0.6 mu mol/L vs 1.8 +/- 0.4 mu mol/L, p < 0.001), while serum nitrite/nitrate was significantly reduced in patients with LAA thrombus (30.3 +/- 7.1 mu mol/L vs 48.4 +/- 9.3 mu mol/L, p < 0.001). ADMA was positively correlated with age and left atrium diameter, and was negatively correlated with nitrite/nitrate and LAA peak flow velocity. The area under the receiver operating characteristic curve of ADMA predicting thrombus was 0.84. In multivariate logistic regression analysis, ADMA (OR 4.0, 95% CI 1.2-13.0; p = 0.003) was one of independent risk factors for LAA thrombus. Conclusions: Our study suggested that high ADMA was independently associated with the presence of LAA thrombus in patients with non-valvular AF. (C) 2015 Elsevier Ltd. All rights reserved.