Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation

Area of Science:

• Cardiology
• Clinical Trials
• Emergency Medicine

Background:

• Patients with recent-onset atrial fibrillation often receive immediate cardioversion.
• The necessity of immediate cardioversion is uncertain due to spontaneous resolution rates.

Purpose of the Study:

• To determine if a wait-and-see approach is noninferior to early cardioversion for recent-onset atrial fibrillation.
• To evaluate the efficacy and safety of delayed versus early cardioversion in hemodynamically stable patients.

Main Methods:

• A multicenter, randomized, open-label, noninferiority trial.
• Patients with recent-onset (<36 hours) symptomatic atrial fibrillation were assigned to a wait-and-see (delayed cardioversion) or early cardioversion group.
• The primary endpoint was sinus rhythm at 4 weeks; noninferiority required the lower bound of the confidence interval to be > -10 percentage points.

Main Results:

• Sinus rhythm at 4 weeks was achieved in 91% of the delayed-cardioversion group and 94% in the early-cardioversion group (difference -2.9 percentage points; 95% CI, -8.2 to 2.2).
• Spontaneous conversion occurred in 69% within 48 hours in the delayed group, versus 16% in the early group.
• Cardiovascular complications were similar between groups (10 vs. 8 patients).

Conclusions:

• A wait-and-see approach is noninferior to early cardioversion for achieving sinus rhythm at 4 weeks in patients with recent-onset, symptomatic atrial fibrillation.
• This suggests that immediate cardioversion may not be necessary for all patients.
• The study highlights the potential for spontaneous resolution and the safety of a delayed approach.