Key Results

Eighty-four patients were enrolled. The median age was in the late 50s. More than a third of patients were female, and three-quarters had a history of atrial fibrillation.

• Primary Outcome: Patients discharged in less than four hours of ED arrival.
  • 32 percent chemical cardioversion first versus 67 percent electrical cardioversion first
  • 36 percent difference (95 percent CI, 16–56 percent; P<0.001), number needed to treat=3.
• Secondary Outcomes: 
  • Median time in the emergency department: 5.1 hours chemical cardioversion first versus 3.5 hours electrical cardioversion first.
  • Adverse events: 24 percent chemical cardioversion first versus 26 percent electrical cardioversion first. Both groups had minimal risk outcomes. There were no strokes or deaths in either group at 30 days.
  • Quality-of-life scores: Similar at 3 and 30 days for both groups across all domains.

Evidence-Based Medicine Commentary

1. Consecutive Patients: Recruitment depended on whether a research assistant was available. This could have introduced selection bias into the study.
2. Exclusion: Patients over the age of 75 were excluded. This could limit the application of these data to older patients who present with atrial fibrillation.
3. Outcome: The primary outcome was changed from ED length of stay to a dichotomous outcome of the proportion of patients discharged within less than four hours of ED arrival. The changing of a primary outcome during a trial can be problematic and has been described in the literature.⁷ However, in this manuscript, the authors explained that the change was made to ensure a straightforward sample size calculation.
4. Tertiary and community: This study included sites ranging from large tertiary referral centers to smaller community hospitals without the availability of on-site cardiologists. This strengthens the validity of the results.
5. External validity: This study was conducted in six urban Canadian emergency departments. It may not have external validity to other countries like the United States, Australia, and the United Kingdom where different approaches to similar patients may be in common use.

Bottom Line

An electrical-first rhythm control cardioversion strategy for acute uncomplicated patients with atrial fibrillation can shorten ED lengths of stay.

Case Resolution

A shared decision is made to use an electrical-first rhythm control cardioversion strategy.

Thank you to Dr. Chris Bond, clinical lecturer at University of Calgary in Alberta, for his help with this review.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine. 

References

1. Naccarelli GV, Varker H, Lin J, et al. Increasing prevalence of atrial fibrillation and flutter in the United States. Am J Cardiol. 2009;104(11):1534-1539.
2. Van Gelder IC, Hagens VE, Bosker HA, et al. A comparison of rate control and rhythm control in patients with recurrent persistent atrial fibrillation. N Engl J Med. 2002;347(23):1834-1840.
3. Wyse DG, Waldo AL, DiMarco JP, et al. A comparison of rate control and rhythm control in patients with atrial fibrillation. N Engl J Med. 2002;347(23):1825-1833.
4. January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2014;64(21):e1-76.
5. Decker WW, Smars PA, Vaidyanathan L, et al. A prospective, randomized trial of an emergency department observation unit for acute onset atrial fibrillation. Ann Emerg Med. 2008;52(4):322-328.
6. Stiell IG, Clement CM, Brison RJ, et al. Variation in management of recent-onset atrial fibrillation and flutter among academic hospital emergency departments. Ann Emerg Med. 2011;57(1):13-21.
7. Ramagopalan S, Skingsley AP, Handunnetthi L, et al. Prevalence of primary outcome changes in clinical trials registered on ClinicalTrials.gov: a cross-sectional study. F1000Res. 2014;3:77.