RE-CIRCUIT Evaluates Dabigatran in Patients Undergoing Catheter Ablation of Atrial Fibrillation
March 19, 2017—The American College of Cardiology (ACC) announced that a study demonstrated the uninterrupted treatment with dabigatran, a non–vitamin K antagonist oral anticoagulant (NOAC), before, during, and after ablation to treat atrial fibrillation significantly reduced the incidence of major bleeding events compared with uninterrupted use of the more established anticoagulant warfarin. The study's Lead Investigator, Hugh Calkins, MD, presented the findings at the ACC's 66th annual scientific session in Washington, DC.
The RE-CIRCUIT trial of uninterrupted dabigatran etexilate in comparison to uninterrupted warfarin in pulmonary vein ablation was funded by Boehringer Ingelheim, which markets dabigatran as Pradaxa.
According to the ACC, the findings offer evidence that dabigatran is a safe and effective alternative to warfarin in the context of atrial fibrillation ablation. The trial showed a 5.3% reduction in its primary endpoint of major bleeding events during ablation or in the first 2 months after the procedure, with major bleeds occurring in 1.6% of study participants who received dabigatran and 6.9% of patients receiving warfarin.
In the announcement, Dr. Calkins stated, “I think it’s great news for the field. There have been very few randomized studies focused on doing ablation procedures in fully anticoagulated patients, and the use of NOACs has been increasing dramatically. I expect these findings will encourage clinicians to quickly shift to doing this procedure with uninterrupted use of NOACs.” Dr. Calkins is Professor of Cardiology at Johns Hopkins Medicine in Baltimore, Maryland. He added, “Anticoagulation management at the time of atrial fibrillation ablation is critically important because stroke and bleeding are both major complications of the procedure.”
The ACC advised that the trial is the largest to compare the uninterrupted use of NOACs to uninterrupted use of warfarin in the context of ablation. The investigators prospectively enrolled 704 patients scheduled for atrial fibrillation ablation at 104 sites in 11 countries and randomly assigned patients to receive either dabigatran or warfarin. Patients started anticoagulant therapy 4 to 8 weeks before ablation and used it continuously for up to 8 weeks after the procedure.
As summarized in the ACC announcement, after excluding patients who did not go through with ablation or failed to meet the study protocol for other reasons, the investigators analyzed outcomes from 317 patients receiving dabigatran and 318 patients receiving warfarin. Dabigatran showed significant improvement over warfarin for the study’s primary endpoint, major bleeding events, and equaled warfarin with regard to secondary safety and efficacy endpoints, which included minor bleeding events, stroke, a composite of major bleeding and stroke, and a composite of all serious adverse events. Only one stroke occurred during the study, and it occurred in a patient assigned to receive warfarin.
Dr. Calkins noted that there is an approved reversal agent for dabigatran, which gives clinicians an additional tool to control major bleeding if it should occur during a procedure.
The findings confirm and enhance the results of previous, smaller studies suggesting NOACs present a lower risk of major bleeding events compared with warfarin, though this study contradicts the findings of one previous, smaller study comparing Pradaxa to warfarin, reported the ACC.