Background: Often atrial fibrillation terminates spontaneously and occasionally recurs; therefore, the advantage of immediate electric or pharmacologic cardioversion over watchful waiting and subsequent delayed cardioversion is not clear.
Study design: Multicenter, randomized, open-label, noninferiority trial.
Setting: 15 hospitals in the Netherlands (3 academic, 8 nonacademic teaching, and 4 nonteaching).
Synopsis: Randomizing 437 patients with early-onset (less than 36 hours) symptomatic AFib presenting to 15 hospitals, the authors showed that, at 4 weeks’ follow-up, a similar number of patients remained in sinus rhythm whether they were assigned to an immediate cardioversion strategy or to a delayed one where rate control was attempted first and cardioversion was done if patients remained in fibrillation after 48 hours. Specifically the presence of sinus rhythm occurred in 94% in the early cardioversion group and in 91% of the delayed one (95% confidence interval, –8.2 to 2.2; P = .005 for noninferiority). Both groups received anticoagulation per current standards.
This was a noninferiority, open-label study that was not powered enough to study harm between the two strategies. It showed a 30% incidence of recurrence of AFib regardless of study assignment. Hospitalists should not feel pressured to initiate early cardioversion for new-onset AFib. Rate control, anticoagulation (if applicable), prompt follow-up, and early discharge (even from the ED) seem to be a safe and practical approach.
Bottom line: In patients presenting with symptomatic recent-onset AFib, delayed cardioversion in a wait-and-see approach was noninferior to early cardioversion in achieving sinus rhythm at 4 weeks’ follow-up.
Dr. Abdo is a hospitalist at Duke University Health System.