Malpractice Counsel: The Challenges of Cardioversion

For patients who have been in AF for less than 48 hours and who are at a very low-embolic risk (CHA₂DS₂-VAS_C score of 0), some experts suggest cardioversion without anticoagulation. However, other experts recommend anticoagulation prior to cardioversion—even in low-risk patients. Unfortunately, there is disagreement between professional organizations, with the American Heart Association/American College of Cardiology/Heart Rhythm Society stating that cardioversion may be performed with or without procedural anticoagulation,² while the 2016 European Society of Cardiology guidelines recommend immediate initiation of anticoagulants in all such patients scheduled for cardioversion.³

The reasoning in favor of anticoagulation prior to cardioversion is supported by an observational study by Airaksinen et al⁴ of 2,481 patients undergoing cardioversion for AF of less than 48 hours duration. This study demonstrated a definite thromboembolic event in 38 (0.7%) of the patients within 30 days (median of 2 days). The thromboembolic event was stroke in 31 of the 38 patients.⁴ Airaksinen et al⁴ found that age older than 60 years, female sex, heart failure (HF), and DM were the strongest predictors of embolization. The risk of stroke in patients without HF and those younger than age 60 years was only 0.2%.⁴

In a similar observational study by Hansen et al⁵ of 16,274 patients in AF undergoing cardioversion with and without anticoagulation therapy, the absence of post­cardio­version anticoagulation increased the risk of thromboembolism 2-fold—regardless of CHA₂DS₂-VAS_C scores.

Summary

While the management of AF with a duration of more than 48 hours should always include some type of anticoagulation therapy (pre- or postcardioversion, or both), the role of anticoagulation in low-risk patients with AF of less than 48 hours is not as clear. As this situation is not uncommon, the emergency medicine and cardiology physicians should consider developing a mutually agreed upon protocol on how best to manage these patients at their institution. When considering cardioversion without pre- or postanticoagulation in low-risk patients with AF, EPs should always involve the patient in the decision-making process.