Abstract and Introduction
Abstract
Background: There are a variety of periprocedural anticoagulation strategies for atrial fibrillation (AF) ablation, including the use of dabigatran. It is unclear which strategy is superior.
Objective: To compare the safety and efficacy of anticoagulation with uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing ablation of AF at four experienced centers.
Methods and Results: In this retrospective analysis, 882 patients (mean age: 61 ± 11 years) underwent ablation of AF using uninterrupted warfarin (n = 276), dabigatran (n = 374), or warfarin with heparin bridging (n = 232) for periprocedural anticoagulation. The rate of total complications was 23/276 (8.3%) in the uninterrupted warfarin group, 30/374 (8.0%) in the dabigatran group, and 29/232 (12.5%) in the bridged group (P = 0.15). Major complications were more frequent in the uninterrupted warfarin group 12/276 (4.3%) compared with 3/374 (0.8%) in dabigatran and 6/232 (2.6%) in the bridged group (P = 0.01). The most common major complication was the need for transfusion or occurrence of major bleeding. Minor complications did not differ among the three groups. On multivariate analysis, female gender (odds ratio [OR] 1.93, confidence interval [CI] 1.16–3.19, P = 0.011), bridging heparin (OR 2.13, CI 1.100–3.941, P = 0.016), use of triple antithrombotic therapy (OR 1.77, CI 1.05–2.98, P = 0.033), and prior myocardial infarction (OR 2.40, CI 1.01–5.67, P = 0.046) independently predicted total complications.
Conclusions: When comparing the use of uninterrupted warfarin, dabigatran, and warfarin with heparin bridging in patients undergoing catheter ablation of AF, dabigatran was not associated with increased risk, major complications were more common in the uninterrupted warfarin group, and after adjustment, warfarin with bridging increased total complications.
Introduction
Atrial fibrillation (AF) is the most common clinical arrhythmia, with an estimated 2.2 million people in the United States and 4.5 million in the European Union afflicted with the disorder.[1] Catheter ablation has become an established invasive strategy for drug refractory AF. Approximately 50,000 ablations are performed annually in the United States, and about 60,000 in Europe,[2] and favorable outcomes suggest that this approach will remain a popular alternative to chronic drug therapy. There are, however, two feared complications that occur during or shortly after the procedure: thromboembolic events including stroke and major bleeding including cardiac tamponade, with an estimated incidence of 1.33% and 0.94%, respectively.[3] The combination of heightened risk of both stroke and hemorrhage is linked to the unique complexity of the AF ablation procedure and to the underlying substrate in patients with AF, and the need to use high-dose periprocedural anticoagulation.
Historically, preprocedure warfarin therapy was discontinued and replaced with bridging low-molecular-weight heparin (LMWH) before and after the ablation, followed by resumption of warfarin at hospital discharge. Although widely adopted throughout the world and endorsed by current formal guidelines, it was recognized that this approach may result in a higher incidence of bleeding complications, especially at the site of vascular access.[4,5] All ablation procedures also use intravenous heparin during the procedure. Several studies have suggested that continuation of therapeutic warfarin could reduce thromboembolic complications without increasing the risk of hemorrhagic complications.[6–8] The recent 2012 HRS/EHRA/ECAS expert consensus statement notes that uninterrupted warfarin is a potential alternative to bridging with LMWH.[5] However, international normalized ratio (INR) levels often fluctuate during warfarin use, and may not be in the optimal therapeutic range in up to >50% of patients.[9] Lower or higher INR levels on the day of ablation may increase the risk of complications.
In late 2010, the U.S. Food And Drug Administration approved the first of three novel oral anticoagulants (NOACs) to be used as an alternative to chronic warfarin for stroke prophylaxis in patients with nonvalvular AF. These newer drugs all have favorable pharmacokinetic profiles that lend themselves to use in the periablation period, including rapid onset of therapeutic effect obviating the need for bridging heparin. Most recent studies, with varying sample sizes, control groups, and anticoagulant regimens, have found dabigatran to be equivalent to warfarin.[10–14] Only a minority of studies have suggested dabigatran is inferior to warfarin.[11]
The purpose of this multicenter study was to determine the relative safety and efficacy of anticoagulation with uninterrupted warfarin, dabigatran, and warfarin with bridging LMWH by collecting data from four high-volume and experienced centers in patients undergoing catheter ablation of AF. This study had the following advantages: one of the largest sample sizes in a diverse cohort of patients and centers employing a range of contemporary ablation techniques and anticoagulation regimens.
Pacing Clin Electrophysiol. 2014;37(6):665-673. © 2014 Blackwell Publishing
