Abstract 2709: Change in Oxidative Stress Expressed by the Urinary Level of 8-Hydroxy-2’-Deoxyguanosine and Biopyrrin Decreases in Atrial Fibrillation: Effect of Sinus Rhythm Restoration
Background: Previous studies have been proposed that there is a link between oxidative stress and atrial fibrillation (AF). Furthermore, oxidative stress may contribute to the pathological consequences of AF such as thrombosis, inflammation, and atrial remodeling. However, little is known about the changes of biomarker of oxidative stress in AF patients. The purposes of this study were to examine the oxidative stress level in AF patients (study-1). Furthermore, we assessed the serial changes of oxidative stress in AF patients before and after cardioversion of AF (study-2).
Methods: Oxidative stress level was evaluated by the urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) level which is regarded as a putative biomarker of systemic oxidative DNA damage and biopyrrin level which is an oxidative metabolites of bilirubin. In the study-1, we compared urinary 8-OHdG between 54 patients with AF and 246 patients with sinus rhythm. In the study-2, we measured urinary 8-OHdG and biopyrrin levels before, at 24 hours and chronic phase (12.0±6.2 months) after cardioversion in 15 patients with persistent AF.
Results: In the study-1, the urinary 8-OHdG/creatinine levels were significantly higher in AF compared with sinus rhythm (20.0±8.9 vs. 13.5±6.2 ng/mg, P < 0.0001). Multivariable analysis revealed that the presence of AF was significantly associated with elevation of urinary 8-OHdG level independently (95% CI, 1.57–7.20; P = 0.002). In the study-2, the urinary biopyrrin/creatinine levels did not significantly change until 24 hours after cardioversion, but significantly decreased at the chronic phase compared with that before cardioversion (3.3±2.5 vs. 1.8±1.6 mU/mg, p = 0.02). Whereas, the urinary 8-OHdG/creatinine significantly decreased 24 hours after cardioversion (18.6±8.9 vs. 14.9±7.9 ng/mg, p = 0.05) and further decreased at chronic phase (8.2±2.8 ng/mg, P < 0.0001 vs. before cardioversion). All patients maintained sinus rhythm in chronic phase.
Conclusions: The oxidative stress level is elevated in AF. Restoration of sinus rhythm by cardioversion decreases oxidative stress level in AF patients. This suggests that the increase of oxidative stress levels, which was produced by AF itself, may contribute to the pathogenic process of the AF perpetuation.