Wong BM, et al. CJEM. 2021 Jul;23(4):500-511. 

Methodology: 4/5
Usefulness: 3.5/5

Question and Methods: Systematic review and meta-analysis of 20 studies to evaluate the effect or oral anticoagulation on thromboembolic events post cardioversion for acute atrial fibrillation or flutter 

Findings: There was insufficient evidence regarding the risk of thromboembolic events associated with oral anticoagulation use following cardioversion for acute atrial fibrillation and flutter. Secondary analysis revealed increased risk of thromboembolic events in patients with high baseline thromboembolic risk score. 

Limitations: English only studies, moderate to high risk of bias throughout included studies, one wild-card reviewer, low overall rate thromboembolic events in included studies, 25% of articles were identified through manual search, 

Interpretation: In acute atrial fibrillation and flutter, there is insufficient evidence to provide certainty regarding the value oral anticoagulation on stroke risk in patients undergoing cardioversion with low baseline thromboembolic risk. Rates of thromboembolic events in the literature are very low, and it is reasonable to engage in shared decision making with patients.

By: Dr. Max Zworth

Journal Club Supervisor: Dr. Ian Stiell

Associate Blog Post:

Atrial Fibrillation/Flutter Best Practice Checklist
Electrical versus pharmacological cardioversion for emergency department patients with acute atrial fibrillation (RAFF2): a partial factorial randomised trial.



  • Max Zworth

    Dr. Zworth is a senior Emergency Medicine resident at the University of Ottawa. His interests include addiction, pain medicine, and sports medicine.

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  • Hans Rosenberg

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

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  • Ian Stiell