Uninterrupted Rivaroxaban Feasible for Patients Undergoing AF Ablation

May 21, 2015

BOSTON, MA — For patients undergoing catheter ablation for nonvalvular atrial fibrillation, continuing with uninterrupted rivaroxaban (Xarelto, Bayer/Janssen Pharmaceuticals) appears to be as safe as uninterrupted oral anticoagulant therapy with warfarin, according to a small study presented last week at the Heart Rhythm Society (HRS) 2015 Scientific Sessions[1].

Overall, the incidence of major bleeding was low (0.4%), regardless of the definition used, with just one major bleeding event occurring in a patient who received uninterrupted warfarin. Regarding the risk of thromboembolic events, one patient had a stroke and one patient died of vascular complications, but both events occurred in patients managed with warfarin therapy.

"There were zero thromboembolic complications in the rivaroxaban group and two [events] in the Coumadin group," senior investigator Dr Andrea Natale (Texas Cardiac Arrhythmia Institute at St David's Medical Center, Austin) said during the late HRS late-breaking clinical-trials presentation. "Both thromboembolic complications did not happen during or in the 48 hours following the procedure. These were not periprocedural complications."

The study, known as the VENTURE-AF trial, which was published May 14, 2015 in the European Heart Journal to coincide with the HRS presentation, included 248 patients with AF randomly assigned to uninterrupted rivaroxaban 20 mg or to uninterrupted warfarin prior to catheter ablation and for 4 weeks after the procedure. The majority of patients included in the study had paroxysmal AF, and the mean CHA2DS2-VASc score was 1.6.

During the presentation, Natale explained the traditional approach when patients undergo catheter ablation is to stop warfarin prior to the procedure and to bridge these patients with parenteral anticoagulation, typically enoxaparin or heparin. This approach in warfarin-managed patients has been challenged in recent years, though, with studies showing the use of an uninterrupted vitamin-K antagonist was associated with fewer thromboembolic events and bleeding complications than bridging.

In fact, Natale was the senior investigator of the COMPARE study, a randomized trial of 1584 patients with a CHADS2 score of >1 undergoing catheter ablation for nonvalvular AF. As reported by heartwire from Medscape, patients bridged with low-molecular-weight heparin had a more than 10-fold increased risk of ischemic stroke or transient ischemic attack (TIA) in the 48 hours after ablation compared with those on uninterrupted warfarin. Regarding safety, the uninterrupted anticoagulant protocol was not associated with an increased risk of bleeding.

An analysis of the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF) trial showed similar results.

Natale said that while more and more operators are opting to keep warfarin-managed patients on treatment during AF ablation, less is known about the safety of a similar approach with the novel oral anticoagulants. VENTURE-AF, he said, was designed solely as an "exploratory" study to determine the feasibility of uninterrupted rivaroxaban in patients undergoing catheter ablation of AF.

According to the International Society on Thrombosis and Haemostasis (ISTH) definition, there was one major bleeding event in a patient who received uninterrupted warfarin and no major events in the rivaroxaban-treated patients. The number of nonmajor bleeding events was similar in both treatment arms, and most of these minor bleeding events were related to the AF procedure, such as hematomas or vessel puncture-site hematomas.

The results of VENTURE-AF, said Natale, suggest that keeping rivaroxaban on board during ablation of AF is feasible, but these results need to be tested in a much larger clinical trial. Based on VENTURE-AF, such a large-scale clinical would be warranted, he added.

At present, there is no clinically available antidote to reverse anticoagulation with rivaroxaban, but one might not be far away. In January, Portola Pharmaceuticals announced that treatment with andexanet alfa "immediately and significantly" reversed the steady-state anticoagulation activity of rivaroxaban. Results of the study, known as ANNEXA-R, were presented at the American College of Cardiology 2015 Scientific Sessions in March.

VENTURE-AF was sponsored by Johnson & Johnson/Bayer. Natale reports additional grant support from/consulting for Biosense Webster, Boston Scientific, Janssen, St Jude Medical, Medtronic, and Biotronik. Disclosures for the coauthors are listed in the article.


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