Assessment of Cardioversion Using Transesophageal Echocardiography - ACUTE


The goal of the trial was to compare three weeks of anticoagulation to an early transesophageal echocardiographic (TEE) approach prior to cardioversion for atrial fibrillation.


Cardioversion of atrial fibrillation using an early TEE-guided approach may reduce the bleeding risks associated with the conventional three weeks of anticoagulation without an increased incidence of embolic events.

Study Design

Study Design:

Patients Enrolled: 1,222
Mean Follow Up: Eight weeks
Mean Patient Age: Mean of 64
Female: 34

Patient Populations:

  • At least 18 years old
  • Atrial fibrillation for at least two days
  • Atrial flutter with documented history of atrial fibrillation


  • History of atrial flutter with no history of atrial fibrillation
  • Hemodynamic instability
  • Patients receiving warfarin therapy for more than seven days' duration
  • Patients with contraindication to warfarin or TEE
  • Women of childbearing potential
  • Impending procedure that would preclude anticoagulation

Primary Endpoints:

Composite primary endpoint: cerebrovascular accident, transient ischemic attack, and peripheral embolism

Secondary Endpoints:

  • Functional status assessed by the Duke Activity Status Index
  • Successful restoration and maintenance of sinus rhythm at eight weeks
  • Major and minor hemorrhage
  • Death

Drug/Procedures Used:

  • Conventional treatment group with warfarin (targeted to international normalized ratio (INR) of 2.0-3.0) for three weeks, followed by cardioversion
  • TEE-guided cardioversion with antecedent warfarin for five days (if outpatient) or intravenous heparin immediately prior to cardioversion (if inpatient)
(If thrombus was detected on initial echocardiography, patients were given three weeks of warfarin followed by repeat echocardiography. If on repeat TEE there was no thrombus, cardioversion was performed. If thrombus was detected on repeat TEE, patients were not cardioverted).

Concomitant Medications:

All patients received warfarin for four weeks following cardioversion.

Principal Findings:

  • No significant difference in the composite endpoint of embolic events (0.8% for TEE-guided group vs. 0.5% for conventional group, p=0.5).
  • Total hemorrhagic events occurred more often in the conventional treatment group (5.5% vs. 2.9%; p=0.03) with no difference in major hemorrhagic events.
  • Patients in the TEE group were cardioverted earlier than those in the warfarin group (3 ± 5.6 days vs. 30.6 ± 10.6 days).
  • At eight weeks: Sinus rhythm was maintained in 52.7% and 50.4% of the TEE and warfarin groups, respectively (p=0.43).
  • There was no significant difference in functional status or death at eight-week follow-up.


Among patients with atrial fibrillation of more than a two-day duration, there was no significant difference in the rate of embolic events with an early TEE-guided approach compared to a conventional approach of three weeks of warfarin anticoagulation prior to cardioversion. The conventional approach was associated with a higher overall rate of hemorrhage, although no significant difference was found in the incidence of major bleeding.


Klein AL, Grimm RA, Murray RD, et al. Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation. N Engl J Med 2001;344:1411-20.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Noninvasive Imaging, Anticoagulation Management and Atrial Fibrillation, EP Basic Science, Atrial Fibrillation/Supraventricular Arrhythmias, Echocardiography/Ultrasound

Keywords: Thrombosis, Warfarin, Electric Countershock, Heparin, Atrial Fibrillation, Echocardiography, Transesophageal, Atrial Flutter

< Back to Listings