L-arginine pathway metabolites can discriminate paroxysmal from permanent atrial fibrillation in acute ischemic stroke.

Background and purpose: Atrial fibrillation (AF) is the most common arrhythmia diagnosed in clinical practice. We aimed to measure the L-arginine pathway metabolites as well as their ratios in patients with different types of AF or sinus rhythm and to explore the relationship among the markers and clinical variables in the subacute phase of acute ischemic stroke (AIS).

Methods: A total of 46 patients with AIS were prospectively enrolled. The patients were divided into three groups based on diagnosis of either sinus rhythm, paroxysmal or permanent AF. Plasma concentration of the L-arginine pathway metabolites were analyzed at post-stroke 24 hours in the three rhythm groups. Besides, clinical variables and laboratory data were recorded.

Results: Asymmetric dimetylarginine (ADMA) was significantly higher in patients with permanent AF compared to sinus rhythm (p<0.001). Both ADMA (p<0.001) and symmetric dimethylarginine (SDMA) (p<0.002) at 24 hours were significantly higher among patients with permanent AF compared to those with paroxysmal AF. The L-arginine/SDMA (p<0.031) ratios at 24 hours were significantly higher among patients with sinus rhythm compared to those with permanent AF. ROC analysis also revealed that plasma SDMA cut-off level over 0.639 μmol/L discriminated permanent AF from paroxysmal AF or sinus rhythm with a 90.9% sensitivity and 77.1% specificity. Neutrophil-lymphocyte ratio also showed significantly higher value in individuals with both paroxysmal and permanent AF (p=0.029).

Conclusion: Plasma level of SDMA could discriminate permanent from paroxysmal AF in the subacute phase of ischemic stroke. In addition, an increased neutrophil-lymphocyte ratio may suggest inflammatory process in the evolution of atrial fibrillation.