Author + information
- Roger A. Winkle, MD⁎ (, )
- R. Hardwin Mead, MD,
- Gregory Engel, MD,
- Melissa H. Kong, MD and
- Rob A. Patrawala, MD
- ↵⁎Silicon Valley Cardiology, 1950 University Avenue #160, E. Palo Alto, California 94303
We read with interest the recent report by Lakkireddy et al. (1) regarding periprocedural dabigatran in patients undergoing atrial fibrillation (AF) ablation. This multicenter study noted a significant increase in bleeding and thromboembolic complications with essentially uninterrupted dabigatran versus uninterrupted warfarin. Their findings emphasize the importance of fully understanding the pharmacokinetics of pharmacologic agents, particularly anticoagulants, which can cause serious complications. Dabigatran possesses several pharmacokinetic properties that are important to safe periprocedural use. These properties predict the potential for increased complications when used in an uninterrupted manner for ablations.
1. There is an in vitro heparin-dabigatran interaction (2). Dabigatran potentiates heparin's antithrombotic properties with quantitatively doubled anticoagulant effect. The increased bleeding complications noted by Lakkireddy et al. (1) suggest that this in vitro interaction very likely occurs in vivo. This interaction is much less apparent with rivaroxaban and apixaban (2).
2. Immediately following hip surgery, dabigatran absorption can be both delayed and reduced (3). Thus, oral dabigatran immediately after an AF ablation may not provide anticoagulation during the immediate post-procedural period. Enoxaparin immediately post-ablation will avoid this anticoagulant lapse until oral absorption of dabigatran occurs.
3. Dabigatran has no direct antidote, so when bleeding complications occur they may be more difficult to treat than those with warfarin.
Based on these pharmacokinetic considerations, we agree it is not appropriate to use dabigatran in a nearly uninterrupted manner. This does not diminish dabigatran's utility when used in an interrupted manner. We have reported the safety of interrupted dabigatran in 123 patients (4) and have subsequently extended our experience to more than 500 patients (40% of whom were on dabigitran pre-ablation) without a single hemorrhagic or thromboembolic complication. As emphasized by Lakkireddy et al. (1), there were significant differences in our use of dabigatran that likely account for the safety and efficacy demonstrated in our series. Heparin administration to patients in whom dabigatran has not been fully interrupted might be expected to lead to increased bleeding complications due to a probable drug-drug interaction and poor absorption post-ablation might lead to increased thromboembolic events. The convenience of standardized oral dosing and elimination of INR monitoring makes dabigatran and other new oral anticoagulants attractive alternates to warfarin for AF ablation patients.
Please note: Dr. Winkle has reported that he has no relationships relevant to the contents of this letter to disclose. Dr. Mead is a consultant and director to iRhythm and Voyage Medical, an advisor to Medtronic and Proteus Biomedical, and a stockholder in iRhythm and Proteus Biomedical. Dr. Engel is a speaker and advisor to Medtronic. Dr. Kong is a member of the Medtronic Advisory Board. Dr. Patrawala is a consultant to and stockholder in Voyage Medical.
- American College of Cardiology Foundation