HRS.15: Uninterrupted rivaroxaban rivals warfarin with ablations

Patients with atrial fibrillation who received an uninterrupted novel oral anticoagulant (NOAC) during catheter ablation fared on par with those treated with an uninterrupted vitamin K antagonist. In either case, bleeding rates in the clinical trial were low.

The results were presented on May 14 at Heart Rhythm 2015 and simultaneously published in the European Heart Journal.

Vitamin K antagonists such as warfarin historically have been the go-to treatment for patients with nonvalvular atrial fibrillation to reduce the risk of stroke. Cardiologists and their patients now have a stable of NOACs as well for this indication. According to one analysis, 62 percent of atrial fibrillation patients prescribed an anticoagulant in the U.S. received NOACs in 2013.

Rivaroxaban (Xarelto, Janssen Pharmaceuticals/Bayer HealthCare), a factor Xa inhibitor, was approved by the FDA in November of 2011. In the same analysis, rivaroxaban had become the market leader, topping warfarin and the other approved NOACs by 2013.

The VENTURE-AF (ActiVe-controlled multi-cENTer stUdy with blind-adjudication designed to evaluate the safety of uninterrupted Rivaroxaban and uninterrupted vitamin K antagonists in subjects undergoing cathEter ablation for non-valvular Atrial Fibrillation) trial compared the use of rivaroxaban or a vitamin K antagonist in patients with paroxysmal, persistent or long-standing persistent nonvalvular atrial fibrillation who were scheduled for a catheter ablation to treat their atrial fibrillation.

The trial, which had a prospective, open-label design, randomized 248 patients from 37 sites between February 2013 and September 2014; of those, 221 underwent catheter ablation. The patients received uninterrupted rivaroxaban at a once daily dose of 20 mg or uninterrupted vitamin K antagonist at recommended standard care before and four weeks after the ablation procedure.

The majority of patients were male, white and had paroxysmal atrial fibrillation. The mean age was 59.5 years and the mean CHA2DS2-VASc score was 1.6.

Compared with the vitamin K antagonist group, the rivaroxaban group required more heparin during ablation (13,871 vs. 10,964 units) and had a lower mean activated clotting time (302 vs. 332 seconds).

The number of bleeding events was low (0.4 percent, with one major bleeding event in the vitamin K antagonist group); there was one stroke and one vascular death, both in the vitamin K antagonist group after ablation; and 21 nonmajor bleeding adverse events in the rivaroxaban group vs. 17 in the vitamin K antagonist group. The overall complication rate was 20.6 percent.

VENTURE-AF is an exploratory study and is not designed to provide statistical superiority or noninferiority. The trial was funded by Janssen and Bayer HealthCare Pharmaceuticals.