Is Cardioversion Right for Patient JB?

August 2, 2016

John Brown is diagnosed with atrial fibrillation in the ED. How would you manage his case from there? Start here.

John Brown is a 58-year-old man with a history of hypertension and hyperlipidemia. He is very active with skiing during the winter and mountain biking during the summer. Three months ago, he went to the emergency department (ED) with unexplained dyspnea and was found to be in atrial fibrillation (AF).

1. If you saw this patient in the ED, would you recommend:

A. Aspirin 81 mg

B. Aspirin 325 mg

C. Anticoagulation with warfarin or a novel oral anticoagulant (NOAC)

D. None of the above

E. Any of the above

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Answer: E. Any of the above.

The ACC/AHA/HRS 2014 atrial fibrillation guidelines indicate that the decision to start anticoagulation should be based on a discussion of risk-benefit ratio with the patient that includes the CHA2DS2-Vasc risk stratification calculator in non-valvular atrial fibrillation and atrial flutter. The decision should be independent of the type of atrial fibrillation (paroxysmal, persistent, permanent) and applies to all atrial flutter. Any patient with a CHA2DS2-Vasc score ≥2 should be treated with oral anticoagulation as he/she is considered moderate to high risk for thromboembolism (Class I). Treatment can be individualized for those with CHA2DS2-Vasc score=1 (Class IIb) and omitted for CHA2DS2-Vasc score=0. John has a CHA2DS2-Vasc risk score=1 so he can be treated with either aspirin or anticoagulation, depending on his  preferences. There is no guideline consensus on whether ASA 81 or ASA 325 mg should be used and either is reasonable based on the patient’s risk of bleeding. The European Society Guidelines recommend full anticoagulation for CHA2DS2-Vasc score=1.

John is sent home with oral anticoagulation and metoprolol. He continues to remain symptomatic despite reasonable rate control. At this time, a rhythm control strategy is chosen and electrocardioversion is scheduled. 

2. What is the level of evidence for a cardioversion strategy? 

A. Class I

B. Class IIa

C. Class IIb

D. Class III

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Answer: A. Class I. 

It is a class I recommendation for patients in AF or atrial flutter to attempt a cardioversion if a rhythm control strategy is chosen. Repeat attempts can be made with an anti-arrhythmic medication (i.e. amiodarone) if the first attempt is unsuccessful. Repeated/serial cardioversions can also be performed if sinus rhythm can be maintained for a reasonable period between cardioversions (Class IIa).

3. How long does John have to been on oral anticoagulation before/after a cardioversion?

A. 2 to 4 wks

B. 3 to 4 wks

C. 2 to 4 mo

D. 3 to 4 mo

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Answer: B. 3 to 4 wks

If AF duration is >48h, then it is reasonabale to either perform a transesophageal echocardiogram (TEE) prior to cardioversion or pursue at least 3 weeks of uninterrupted oral anticoagulation (with documented INR values or compliance with NOACs) (Class IIa). If AF duration is <48h and the CHA2DSDS2-Vasc score is low, then cardioversion can be considered without TEE and without the need for post-cardioversion oral anticoagulation (Class IIb, Level of evidence C). After cardioversion, the decision for long term anticoagulation should be based on the CHA2DSDS2-Vasc score (thromboembolic risk) and not whether or not the patient is maintaining sinus rhythm.

For Part II of this case, please click here.