April 18, 2019
4 min read

Delayed cardioversion noninferior to early cardioversion for AF

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Jeff S. Healey
Jeff S. Healey

A wait-and-see approach for patients who presented to the ED with atrial fibrillation was noninferior to early cardioversion for return to sinus rhythm at 4 weeks, according to results from the RACE 7 ACWAS trial published in The New England Journal of Medicine.

“The wait-and-see strategy, with delayed cardioversion if needed within 48 hours after symptom onset, has several advantages for patients,” Nikki A.H.A. Pluymaekers, MD, of Maastricht University Medical Center, and colleagues wrote. “First, cardioversion (along with its potential complications) may be avoided. Second, the time spent in the emergency department during the initial presentation may be reduced. Third, spontaneous conversions of atrial fibrillation may be observed, leading to fewer misclassifications of persistent atrial fibrillation. ... Fourth, patients may have the experience that their arrhythmia terminated by itself, which may broaden their insight into treatment options.”

Delayed vs. early cardioversion

Researchers analyzed data from 437 patients (mean age, 65 years; 40% women) who presented to the ED with hemodynamically stable, symptomatic, recent-onset AF from October 2014 to September 2018. Patients were assigned either delayed cardioversion (n = 218) or early cardioversion (n = 219).

Patients in the delayed cardioversion group, also called the wait-and-see approach, were administered rate-control medication and were discharged once their condition was stable. An outpatient clinic visit was scheduled the next day or as close to 48 hours after symptom onset, when heart rhythm was reassessed by ECG. Patients were referred to the ED if symptoms were still present to undergo delayed cardioversion. The early cardioversion group underwent the procedure during their ED visit and were discharged once they were stabilized.

A follow-up visit was scheduled at 4 weeks for all patients to collect information on medication use, symptomatic recurrences, hospital admissions and complications.

The primary endpoint was sinus rhythm on ECG during the follow-up visit at 4 weeks. Secondary endpoints included factors such as the time to AF recurrence and CV complications.

At 4 weeks, the presence of sinus rhythm occurred in 91% of patients assigned delayed cardioversion and 94% of those assigned early cardioversion (between-group difference = –2.9 percentage points; 95% CI, –8.2 to 2.2; P for noninferiority = .005).

Within the delayed cardioversion group, more patients who only received rate-control medication returned to sinus rhythm within 48 hours compared with those who underwent delayed cardioversion (69% vs. 28%). More patients in the early cardioversion group returned to a normal sinus rhythm after cardioversion vs. before the initiation of cardioversion in patients from the same group (78% vs. 16%).


Recurrence and complications

AF recurred in 30% of patients assigned delayed cardioversion and 29% of those assigned early cardioversion within 4 weeks after the index visit.

At 4 weeks after randomization, CV complications were observed in 10 patients from the delayed cardioversion group and 8 patients in the early cardioversion group.

“Therapy to prevent recurrent hospitalization for atrial fibrillation is another key component of long-term care, since most patients who present to the emergency department have recurrent atrial fibrillation,” Jeff S. Healey, MD, FRCPC, professor in the division of cardiology at McMaster University in Hamilton, Ontario, and William F. McIntyre, MD, cardiologist and research fellow in cardiac arrhythmia at McMaster University, wrote in a related editorial. “The management of atrial fibrillation in the emergency department is not only a sprint to eliminate symptoms and facilitate safe discharge, but also the start of a marathon to improve long-term outcomes for patients.” – by Darlene Dobkowski

Disclosures: Boehringer Ingelheim provided some remote monitoring devices for this study. Pluymaekers reports no relevant financial disclosures. Healey reports he received grants from Boston Scientific, Bristol-Myers Squibb/Pfizer and Medtronic and personal fees from Boston Scientific, Bristol-Myers Squibb/Pfizer, Medtronic and Servier. McIntyre reports he received personal fees from Bayer, Bristol-Myers Squibb/Pfizer and Servier. Please see the study for all other authors’ relevant financial disclosures.