In patients with atrial fibrillation (AF) undergoing catheter ablation, uninterrupted anticoagulation with dabigatran, an oral, non-vitamin K antagonist, reduces the number of major bleeding events compared with uninterrupted anticoagulation with the vitamin K antagonist warfarin. This finding was presented at ACC.17 and simultaneously published in N. Engl. J. Med.

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Cerebrovascular events are serious complications of ablation in AF, and systemic anticoagulation with warfarin has been shown to reduce this risk. However, limited clinical data exist on the use of alternative anticoagulation strategies during ablation, such as the continuous use of non-vitamin K antagonists. The investigators of the open-label, multicentre, randomized, controlled RE-CIRCUIT trial, randomly assigned 635 patients with paroxysmal or persistent AF scheduled to receive catheter ablation to either dabigatran (150 mg twice daily) or warfarin (target international normalized ratio 2.0–3.0). Anticoagulation treatment was initiated 4–8 weeks before ablation, and continued during the procedure, and for 8 weeks after ablation.

The primary end point of the trial — major bleeding events occurring from the start of ablation up to 8 weeks after the procedure — was significantly lower in the dabigatran group than in the warfarin group (1.6% vs 6.9%; absolute risk difference −5.3 percentage points, P <0.001). The incidence of minor bleeding events (the secondary end point) was similar in the two groups. One thromboembolic event occurred in the warfarin group.

dabigatran is safer than warfarin in patients with AF undergoing ablation

These results indicate that continuous anticoagulation with dabigatran is safer than warfarin in patients with AF undergoing ablation. The investigators speculate that these results might be due to the more specific mechanism of action and shorter half-life of dabigatran.