Apixaban Lowers Stroke Risk in Atrial Fibrillation Patients Undergoing Cardioversion - EMANATE

Contribution To Literature:

The EMANATE trial showed that short-duration apixaban was feasible in patients with atrial fibrillation undergoing cardioversion.


The goal of the trial was to evaluate short-duration apixaban compared with warfarin with among patients with atrial fibrillation undergoing cardioversion.

Study Design

  • Randomized
  • Parallel

Patients with predominately new-onset atrial fibrillation undergoing cardioversion were randomized to short-duration (<48 hours) apixaban 5 mg twice daily (n = 753) versus heparin/warfarin (n = 747). Patients randomized to apixaban could receive a 10 mg loading dose and undergo cardioversion after 2 hours. Transesophageal echocardiography (TEE) was encouraged, but not mandated. Approximately 50% of the patients underwent TEE prior to cardioversion.

  • Total number of enrollees: 1,500
  • Duration of follow-up: 30 days
  • Mean patient age: 65 years
  • Percentage female: 33%
  • Percentage with diabetes: 21%

Inclusion criteria:

  • Anticoagulation-naïve patients with atrial fibrillation
  • Scheduled for cardioversion

Exclusion criteria:

  • Contraindication to anticoagulation
  • Mitral stenosis or previous valve surgery
  • Other condition requiring anticoagulation
  • On dual antiplatelet therapy

Principal Findings:

The primary outcome, incidence of stroke or systemic embolism, occurred in 0% of the apixaban group versus 0.8% of the heparin/warfarin group (p = 0.016).

Secondary outcomes:

  • Major bleeding: 0.4% of the apixaban group vs. 0.8% of the heparin/warfarin group
  • Clinically relevant nonmajor bleeding: 1.5% of the apixaban group vs. 1.8% of the heparin/warfarin group
  • Thrombus was present among 7.2% (61 of 840) of patients who underwent a TEE. Among those who underwent repeat imaging, approximately 1 month later, thrombi resolved in 52% of the apixaban group and 56% of the heparin/warfarin group.


Among patients with atrial fibrillation, short-duration apixaban (<48 hours) is feasible compared with short-duration heparin/warfarin. Short-duration apixaban was associated with a lower frequency of stroke or systemic embolism and similar incidence of bleeds compared with heparin/warfarin. This approach does not obviate the need for TEE since imaging disclosed approximately 7% of patients with thrombi, of which only one half had resolved by 1 month.


Ezekowitz MD, Pollack CV Jr, Halperin JL, et al. Apixaban compared to heparin/vitamin K antagonist in patients with atrial fibrillation scheduled for cardioversion: the EMANATE trial. Eur Heart J 2018;Apr 6:[Epub ahead of print].

Presented by Dr. Michael D. Ezekowitz at the European Society of Cardiology Congress, Barcelona, Spain, August 28, 2017.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Noninvasive Imaging, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Echocardiography/Ultrasound

Keywords: Arrhythmias, Cardiac, Atrial Fibrillation, Anticoagulants, Echocardiography, Transesophageal, Electric Countershock, Embolism, ESC2017, ESC Congress, Hemorrhage, Heparin, Secondary Prevention, Stroke, Thrombosis, Warfarin

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