RESUMO
BACKGROUND: Although there is evidence that inflammation and oxidative stress might contribute to the pathogenesis of atrial fibrillation (AF), the predictive value of inflammatory and oxidative stress markers in patients with AF has not been fully assessed. The aim of this study is to evaluate these markers as predictors of sinus rhythm (SR) maintenance, in patients with persistent lone AF. METHODS: Among 268 patients with symptomatic AF, we studied 46 patients with a first episode of recently established persistent lone AF. We measured the circulating levels of hs-CRP, TNF-alpha, IL-6, IL-10, sICAM-1, sVCAM-1, malondialdehyde (MDA) and nitrotyrosine (NT) before, 1 h, 24 h, 1, 2, 4 and 6 weeks after cardioversion. During a 12-month follow-up period, AF recurrence was evaluated by Holter ECG recordings every month and when symptoms were reported. RESULTS: Baseline levels of CRP, TNF-alpha, sICAM-1, MDA, and NT were elevated in patients with AF compared to controls, and higher in patients with than in those without persistent AF recurrence, while IL-6 levels were equally elevated in the two subgroups. SR maintenance was associated with lower baseline MDA values and faster decrease in IL-6, sICAM-1 and NT levels within the first 2 weeks following SR restoration. CONCLUSIONS: Increased markers of inflammation and oxidative stress are found in patients with lone AF, implying that inflammation and oxidative stress may be associated with the presence of the arrhythmia. IL-6, sICAM-1, MDA and NT, assessed prior to and after the first cardioverted episode of persistent arrhythmia, appear to be reliable, early predictors of SR maintenance during the following year.