Abstract
Background: Although catheter ablation, including pulmonary vein isolation, is the primary nonpharmacological therapy for atrial fibrillation (AF), atrial arrhythmia often recurs. Recent studies have linked circulating mitochondrial cell-free DNA (mt-cfDNA), a potential contributor to inflammatory disorders, with AF. In this study, we evaluated the relationship between plasma mt-cfDNA levels and AF recurrence after catheter ablation in patients with AF. Methods: Peripheral blood was obtained from 58 patients with AF (34 paroxysmal and 24 persistent AF) who underwent catheter ablation and from the control group (10 patients without AF). We extracted total cfDNA and mt-cfDNA from the patients. Results: The total cfDNA concentration and copy number of mt-cfDNA were significantly higher in patients with AF than in controls. During the 16-month follow-up after catheter ablation, AF recurred in 11 patients (19.0 %). In patients with AF, the copy number of mt-cfDNA before catheter ablation was higher in the recurrent group than in the non-recurrent group. However, total cfDNA concentrations did not differ significantly between patients with and without AF recurrence. The left atrial volume index (LAVI) was higher in patients with recurrent AF than in those without. Cox proportional hazards regression analysis showed that the mt-cfDNA copy number was significantly associated with AF recurrence after catheter ablation, independent of age, sex, body mass index, LAVI, and AF type. Conclusion: Elevated mt-cfDNA levels may be a sensitive predictor of AF recurrence after catheter ablation in patients with AF.