Abstract 9301: The Comparison of Warfarin and Dabigatran in the Incidence of Asymptomatic Cerebral Micro Thromboembolism after AF Ablation

Background: Asymptomatic cerebral thromboembolism after atrial fibrillation (AF) ablation has been reported in 4-20% of the patients. Uninterrupted anticoagulation therapy using warfarin has been shown to be effective for preventing perioperative cerebral thromboembolism without increasing the bleeding complications. Dabigatran, a new anticoagulation agent, has been reported the comparable effects for preventing symptomatic thromboembolic events in non-valvular AF patients. Thus we investigated the incidence of asymptomatic cerebral thromboembolism after AF ablation with dabigatran compared with warfarin using diffusion- and T2-weighted magnetic resonance imaging (DW/T2-MRI). Methods: This study was a prospective non-randomized observational study included 210 consecutive patients (112 paroxysmal AF) who underwent AF ablation solely guided by complex fractionated atrial electrograms (n=113) or combined with PVI (n=97). Warfarin was used for perioperative anticoagulation therapy in 180 patients (warfarin group), and dabigatran was used in 30 patients (dabigatran group). Warfarin was not discontinued for the procedure, whereas dabigatran was not prescribed in the morning of the procedure. Irrigation catheters with the maximum power of 40 watts were used in all the cases. All the patients underwent cerebral DW/T2-MRI in the day after ablation. Results: The incidence of asymptomatic cerebral thromboembolism and hemopericardium treated with pericardiocentesis was higher in dabigatran group than in warfarin group [20.0% vs 7.8% (P<0.05), 13.3% vs 2.2% (P<0.05), respectively]. Although left atrial (LA) diameter and left ventricular (LV) mass were smaller in dabigatran group than in warfarin group [40+9 mm vs 43+7 mm (P<0.05), 189.6+53.0 g vs 161.9+34.8 g (P<0.05), respectively], there was no significantly difference in age, CHADS2 score, the proportion of paroxysmal/persistent AF, LA appendage flow speed, LV ejection fraction, mean activated coagulation time during the procedure, and radiofrequency time between the both groups. Conclusion: Perioperative uninterrupted anticoagulation therapy using warfarin was safer and more effective compared with dabigatran for catheter ablation of AF.