Journal Club Summary

Methodology Score: 4/5
Usefulness Score: 2/5

Pluymaekers NAHA, et al. N Engl J Med. 2019 Mar 18. 

Editorial: The RACE to Treat Atrial Fibrillation in the Emergency Department. 

Question and Methods: This multicenter, randomized, open-label, non-inferiority trial compared delayed vs early cardioversion for emergency department patients with recent-onset, symptomatic atrial fibrillation.

Findings: Sinus rhythm at four weeks was present for 91% of patients in the delayed cardioversion group and 94% of patients in the early cardioversion group (p=0.005 for non-inferiority).

Limitations: This study was not powered to assess safety, but cardiovascular complications were rare in both groups.

Interpretation: Rate control with delayed cardioversion may be an acceptable alternative to early cardioversion when managing patients with paroxysmal atrial fibrillation.

By: Dr. Bo Zheng 

Epi Lesson Non-inferiority Trials      

Most RCTs aim to determine whether one intervention is superior to another (superiority trials). Often a non-significant test of superiority is wrongly interpreted as proof of no difference between the two treatments (in fact the intervention may be inferior to the standard therapy offered). Non-inferiority trials are distinct from superiority trials such that they are designed to determine whether a given intervention is non-inferior by a pre-specified margin compared to a control.  This pre-specified margin is critical.  It should be well described, justified and reasonable. The critical reader will ask themselves if they feel this margin is truly clinically significant.  Analyses should follow a per-protocol analytical approach, such that patients are analyzed only when the treatment was as planned. Otherwise, if you have cross overs, this dilutes the chances of finding a difference between the treatment arms and may lead you to erroneously determining that the new treatment is non-inferior to the standard, only because many patients in the new treatment arm received the standard treatment.

By: Dr. Jeff Perry

Hans Rosenberg
Dr. Rosenberg is an emergency physician at the Ottawa Hospital, assistant professor at the University of Ottawa, and Director of the Digital Scholarship and Knowledge Dissemination Program.