Lingering concerns about the use of continuous dabigatran (Pradaxa) for atrial fibrillation catheter ablations have now been put to rest say experts following the release of new data at the American College of Cardiology conference this week.
The findings from the RE-CIRCUIT trial presented in a late breaking session and published simultaneously in the New England Journal of Medicine found patients had fewer major periprocedural bleeding events when treated with uninterrupted dabigatran compared with warfarin.
The trial included 678 AF patients scheduled for catheter ablation who were randomised to receive either uninterrupted dabigatran 150 mg twice daily or warfarin.
Patients on dabigatran reported significantly fewer major bleeding events (primary end point) than patients on warfarin (1.6% vs 6.9%; P = 0.0009), representing a 77.2% relative risk reduction with the DOAC.
There were no instances of death, stroke, or systemic embolism in any patients, but one TIA occurred in the warfarin arm, revealed the study that followed patients for up to eight weeks.
Meanwhile minor bleeding events did not differ between groups.
Electrophysiologist at Epworth Hospital in Melbourne, Dr Andrei Catanchin said the trial strongly supports a practice that some doctors have already adopted since the reversal agent for dabigatran, idarucizumab (Praxbind), became available last year.
“Warfarin is reversible and has been the standard of care for some years now but very few ablation doctors would perform AF ablation, one of the most invasive cardiac procedures that carries significant risk, on uninterrupted DOAC because of the lack of a reversal agent.
“Idarucizumab has removed that issue and has meant, in theory at least, that continuous anticoagulation could now be safely performed on this DOAC. The RE-CIRCUIT trial very strongly supports this practice.”
Also speaking to the limbic, Associate Professor John Amerena, director of the Geelong Cardiology Research Unit in Victoria, agreed that the introduction of idarucizumab has motivated the adoption of uninterrupted dabigatran as the preferred anticoagulation strategy in patients undergoing AF ablation.
“Until recently, if you were on an any one of the DOACs you would be at risk of a serious bleeding event if you were unlucky enough to have a complication during catheter ablation.
Without a reversal agent we wouldn’t be able to do anything about it as opposed to warfarin where you can give prothrombin complex or vitamin k to try and turn off the bleeding.
“But that concern has really dissipated now because we have a rapidly acting reversal agent for dabigatran.
And we now also have a study that has shown that we can continue dabigatran safely with better outcomes and less bleeding. I think that will give people a lot of reassurance.”
Meanwhile Dr Catanchin also noted that while the reversal agent for dabigatran became available halfway through the trial, it was not actually used in patients who experienced complications.
“Reversal of warfarin was however, required in a number of cases in the warfarin arm and there were significantly more procedural complications on warfarin,” he added.
Dr Catanchin said that he was surprised at the ‘magnitude of benefit’ that continuous dabigatran resulted in compared to warfarin.
“In theory warfarin, which is a more complex anticoagulant, might provide better cover than the much more targeted DOACs but in fact dabigatran provides equal stroke prevention with much lower bleeding risk, less complications and less serious adverse events.
He added that the study findings could have implications beyond AF ablation, noting that catheter ablation for atrial flutter and other arrhythmias and pacemaker procedures are all commonly performed with uninterrupted warfarin.
Meanwhile, Professor Amerena cautioned that while the findings from RE-CIRCUIT might be suggestive of a class effect he would be hesitant to generalise the results to other DOACs.
“If uninterrupted therapy works with dabigatran it probably works for apixaban and rivaroxaban but I think you’d be more hesitant to just continue them – we haven’t got the evidence yet and we haven’t got a reversal agent if something went wrong.”
The trial was funded by Boeringher Ingelheim. Associate Professor Amerena and Dr Catanchin have reported receiving lecture fees and fees for serving on advisory boards from Boeringher Ingelheim.