麻豆传媒

ANAHEIM -- Holding a dose or two of dabigatran (Pradaxa) before ablation for atrial fibrillation reduces major bleeding risk compared with uninterrupted warfarin, the ABRIDGE-J trial showed.

Incidence of a first adjudicated major bleeding events was significantly lower at 3 months with that minimally-interrupted dabigatran strategy than with warfarin (1.4% versus 5.0%, three versus 11 cases, P=0.032), Akihiko Nogami, MD, of the University of Tsukuba, Japan, reported here at the American Heart Association meeting.

Ischemic events were only one case of cerebral infarction in the warfarin group and none in the dabigatran group (0.5% versus 0.0%, P=N.S.), leaving a lower net composite incidence of major bleeding and thromboembolic events at 3 months and 1 year.

The composite of all bleeding and ischemic events was in a similar direction but without statistical significance. The findings were consistent across subgroups.

And the findings were consistent with other recent trials showing the non-vitamin K antagonist oral anticoagulants (NOACs) to be fairly safe periprocedurally in atrial fibrillation, Jagmeet Singh, MD, PhD, of Massachusetts General Hospital in Boston, noted in an interview with 麻豆传媒. Singh was not involved in the trial.

RE-CIRCUIT, for instance, showed less major bleeding with uninterrupted dabigatran versus uninterrupted warfarin.

Now the ABRIDGE-J findings say "maybe in certain subsets of patients who may be at high risk for vascular compilations you could interrupt dabigatran and get away with it fairly safely," he said. "Having strategies for patients who are on these novel oral anticoagulants is important and it allows us to individualize our treatment strategy based on what the subset of patients are."

Study discussant Jonathan Piccini, MD, of Duke, agreed that uninterrupted and minimally-interrupted NOAC therapy are both reasonable treatment strategies, as reflected in 2017 consensus guidelines.

The trial randomized 500 adults at 28 sites in Japan who were getting an initial ablation procedure for paroxysmal or persistent nonvalvular atrial fibrillation to receive warfarin without interruption or dabigatran with one to two doses withheld prior to the ablation based on the scheduled time of ablation (with heparin bridging recommended if the gap was ≥24 hours) and resumed within 18 hours afterward.

In the 37% of dabigatran group participants for whom the interruption was at least 24 hours, 70% were heparin-bridged.

There were too few events to analyze by interval of interruption of dabigatran, Nogami said. However, activated partial thromboplastin time volume was significantly lower for patients with dabigatran interrupted more than 24 hours without heparin bridging. And, all three dabigatran-treated patients with a major bleeding events had interruption of drug before ablation for at least 24 hours without heparin bridging.

Piccini cautioned about the relatively small size of the trial that left it underpowered for thromboembolic events. He also noted the significant proportion who got heparin bridging as a factor that may make interpretation challenging, along with questions of generalizability outside of Japan.

Nonetheless, the findings help confirm guidelines in that holding a dose or two is a reasonable alternative to uninterrupted oral anticoagulation, Piccini said.

Future studies should compare minimally and uninterrupted NOAC treatment in this setting to determine which is best, he suggested.

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