Archief Roodbont

In warfarin recipients with therapeutic international normalized ratios (INRs), uninterrupted warfarin treatment during radiofrequency ablation for atrial fibrillation (AF) has relatively convincingly been shown to reduce both thromboembolic and bleeding events. Dabigatran is increasingly prescribed as an alternative to warfarin in patients with nonvalvular AF. However, dabigatran's half life ranges from 12 to 14 hours and is prolonged in patients with renal insufficiency. Given the lack of an antidote to reverse its effects, the drug's safety and efficacy during ablation are not clear.

Investigators used prospective data from a multicenter registry to compare the results of AF ablation in 145 patients taking dabigatran with the results in a matched cohort of 145 warfarin recipients with therapeutic INRs. Dabigatran was withheld on the day of surgery and restarted 3 hours after ablation; warfarin treatment was uninterrupted. The rate of major bleeding (pericardial tamponade) was 6% with dabigatran and 1% with warfarin (P=0.009). The rate of thromboembolic complications was also higher with dabigatran than with warfarin (2% vs. 0%), but this difference was not statistically significant.

Comment: These findings are by no means definitive. All of the warfarin patients had therapeutic international normalized ratios — a more realistic control group would have been a matched sample of all warfarin recipients. The optimal role of dabigatran in patients with atrial fibrillation undergoing ablation has yet to be determined. We need more data before we open the floodgates, and an editorialist describes a number of alternative strategies for anticoagulation during AF ablation. Still, this report does provide some practical guidance: Dabigatran should be discontinued before the day of the ablation, probably for at least 24 hours.

— Mark S. Link, MD

Published in Journal Watch Cardiology February 29, 2012