Insight

Fewer Bleeding Complications with Uninterrupted Dabigatran Versus Warfarin for Ablation in Atrial Fibrillation
Catherine Amey, Senior Medical Writer, Touch Medical Media, Reading, UK

Uninterrupted anticoagulation during atrial fibrillation ablation was associated with a lower rate of major bleeding events when using dabigatran rather than warfarin, according to the findings of the Uninterrupted Dabigatran Etexilate in Comparison to Uninterrupted Warfarin in Pulmonary Vein Ablation (RE-CIRCUIT) trial.1

The study, reported simultaneously at the American College of Cardiology (ACC) Meeting, and online in the New England Journal of Medicine2 found that major bleeding events during ablation and up to eight weeks following ablation occurred at a statistically significant lower incidence with dabigatran (150 mg twice daily) than with warfarin (target international normalised ratio, 2.0 to 3.0): 1.6% (five patients) versus 6.9% (22 patients), respectively. The absolute risk difference was -5.3 percentage points; 95% confidence interval: -8.4 to -2.2; p<0.001.

Dabigatran use was also associated with significantly fewer periprocedural pericardial tamponade and groin haematomas. Only one thromboembolic event occurred in the trial, which was in the warfarin group. The incidence of minor bleeding events did not differ between the two groups.

'These results are exciting news for the medical community,' said Professor Hugh Calkins, chairman of the RE-CIRCUIT study steering committee and professor of cardiology and director of the electrophysiology laboratory and arrhythmia service, Johns Hopkins Hospital, Baltimore, US. 'During an ablation procedure, patients are at risk of potential major complications, including stroke and bleeding. Therefore, anticoagulation management at the time of atrial fibrillation ablation is critically important.'

The reversal agent for dabigatran – idarucizumab – became available during the RE-CIRCUIT trial, although 'all the bleeding events in the dabigatran group were managed without the need for dabigatran reversal, which is reassuring,' the study investigators noted.

Mechanisms for the fewer bleeding events associated with dabigatran may involve the shorter half-life of dabigatran, and direct thrombin inhibition, rather than effects on coagulation factors.

RE-CIRCUIT, a randomised, open-label controlled trial with blinded adjudicated end-point assessments, enrolled 704 patients across 104 sites. In total, 635 patients underwent ablation, which was performed after four to eight weeks of uninterrupted anticoagulation. The trial only investigated dabigatran, one non-vitamin K oral anticoagulant (NOAC), versus warfarin and head-to-head comparative data among other drugs of the class are needed to determine whether there is a class effect.

Funding
The RE-CIRCUIT study was funded by Boehringer Ingelheim.

Disclosures: Catherine Amey is an employee of Touch Medical Media.

1. Calkins H, Willems S, Gerstenfeld EP, et al., Uninterrupted Dabigatran versus Warfarin for Ablation in Atrial Fibrillation, N Engl J Med, 2017;376:1627–36.
2. Calkins H, Willems S, Verma A et al., Safety and Efficacy of Uninterrupted Anticoagulation With Dabigatran Etexilate Versus Warfarin in Patients Undergoing Catheter Ablation of Atrial Fibrillation: The RE-CIRCUIT Study, Presented at: American College of Cardiology 66th Annual Scientific Session, Washington, DC, US, 20 March 2017. Abstr#411-08.