Oral rivaroxaban appears to be an effective and safe alternative to vitamin K antagonists (VKAs) in patients with nonvalvular atrial fibrillation (AFib) and may allow prompter elective cardioversion, according to results of the X-VeRT Trial presented Sept. 2 at ESC Congress 2014 and simultaneously published in the European Heart Journal.

The trial randomized 1,504 nonvalvular AFib patients undergoing elective cardioversion from 141 centers across 16 countries to rivaroxaban (20 mg once daily, 15 mg if creatinine clearance was between 30 and 49 mL/min) or dose-adjusted VKAs in a 2:1 ratio. Patients were also assigned to either an early (1–5 days) or delayed (3–8 weeks) cardioversion strategy.

Of these patients, 0.51 percent in the rivaroxaban group experienced primary efficacy events – stroke, transient ischemic attack, peripheral embolism, myocardial infarction or cardiovascular death – compared to 1.02 percent in the VKA group. The percentage of primary efficacy events following early cardioversion was somewhat similar across both groups, with 0.71 percent of rivaroxaban patients and 1.08 percent of VKA patients experiencing events. The difference was more significant following delayed cardioversion with 0.24 percent of rivaroxaban patients experiencing events, compared to 0.93 in the VKA group.

Study investigators also noted that rivaroxaban was associated with a significantly shorter time to cardioversion compared with VKAs (P < 0.001). In terms of major bleeding, results were similar across both groups with 0.6 percent of rivaroxaban patients and 0.8 percent of VKA patients experiencing bleeding events.

While the study was underpowered and "thus exploratory in nature for the comparison between rivaroxaban and VKAs," the investigators noted that the "95 percent upper confidence limits of incidences for rivaroxaban in efficacy (1.17 percent) and safety (1.27 percent) suggest a reassuring efficacy and safety profile."

Keywords: Vitamin K, Myocardial Infarction, Stroke, Ischemic Attack, Transient, Morpholines, Thiophenes, Electric Countershock, Embolism, Creatinine