Pluymaekers NAHA, et al. - Given that patients with recent-onset atrial fibrillation (AF) commonly experience immediate restoration of sinus rhythm by pharmacologic or electric cardioversion, researchers examined the necessity of immediate restoration of sinus rhythm since AF often terminates spontaneously. The investigators noted noninferiority of a wait-and-see approach to early cardioversion in achieving a return to sinus rhythm at 4 weeks among patients presenting to the emergency department with recent-onset, symptomatic AF.

Methods

• Participants included patients with hemodynamically stable, recent-onset (< 36 hours), symptomatic AF who presented to the emergency department.
• Patients were randomized to a wait-and-see approach (delayed-cardioversion group) or early cardioversion.
• The wait-and-see approach comprised initial treatment with rate-control medication only, and delayed cardioversion if the AF did not resolve within 48 hours.
• The presence of sinus rhythm at 4 weeks was assessed as the primary end point.
• More than −10 lower limit of the 95% confidence interval for the between-group difference in the primary end point in percentage points was considered as noninferiority.

Results

• In the delayed-cardioversion group, the presence of sinus rhythm at 4 weeks occurred in 193 of 212 patients and, in the early-cardioversion group, it occurred in 202 of 215 (between-group difference, −2.9 percentage points; 95% CI: −8.2 to 2.2; P=0.005 for noninferiority).
• Conversion to sinus rhythm within 48 hours occurred spontaneously in 150 of 218 patients in the delayed-cardioversion group and in 61 patients after delayed cardioversion.
• In the early-cardioversion group, 16% of patients had conversion to sinus rhythm spontaneously before the initiation of cardioversion and 78% of patients had after cardioversion.
• They observed a recurrence of AF in 49 of 164 patients in the delayed-cardioversion group and in 50 of 171 in the early-cardioversion group among the patients who completed remote monitoring during 4 weeks of follow-up.
• They noted cardiovascular complications within 4 weeks after randomization in 10 patients and 8 patients, respectively.