Aim: The primary objective was to compare apixaban to heparin/vitamin K antagonist (VKA) in patients with atrial fibrillation (AF) and ≤48 h anticoagulation prior to randomization undergoing cardioversion.
Methods: One thousand five hundred patients were randomized. The apixaban dose of 5 mg b.i.d. was reduced to 2.5 mg b.i.d. in patients with two of the following: age ≥ 80 years, weight ≤ 60 kg, or serum creatinine ≥ 133 µmol/L. To expedite cardioversion, at the discretion of the investigator, imaging and/or a loading dose of 10 mg (down-titrated to 5 mg) was allowed. The endpoints for efficacy were stroke, systemic embolism (SE), and death. The endpoints for safety were major bleeding and clinically relevant non-major (CRNM) bleeding.
Results: There were 1038 active and 300 spontaneous cardioversions; 162 patients were not cardioverted. Imaging was performed in 855 patients, and 342 received a loading dose of apixaban. Comparing apixaban to heparin/VKA in the full analysis set, there were 0/753 vs. 6/747 strokes [relative risk (RR) 0; 95% confidence interval (95% CI) 0-0.64; nominal P = 0.015], no SE, and 2 vs. 1 deaths (RR 1.98; 95% CI 0.19-54.00; nominal P > 0.999). In the safety population, there were 3/735 vs. 6/721 major (RR 0.49; 95% CI 0.10-2.07; nominal P = 0.338) and 11 vs. 13 CRNM bleeding events (RR 0.83; 95% CI 0.34-1.89; nominal P = 0.685). On imaging, 60/61 with thrombi continued randomized treatment; all (61) were without outcome events.
Conclusions: Rates of strokes, systemic emboli, deaths, and bleeds were low for both apixaban and heparin/VKA treated AF patients undergoing cardioversion.
Clinical trials.gov number: NCT02100228.