ESC Congress 2017 In Review – Focus on Arrhythmias - 12

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Anticoagulation for Cardioversion
of Atrial Fibrillation
Written by Maria Vinall

October 2017

Figure 1. Thromboembolism After Discharge for DC Cardioversion of AF
4

100

Patients with Event
of Thromboembolism (%)

During this special update session, experts in the field
discussed some of the areas of uncertainty in the use of
anticoagulation for cardioversion of atrial fibrillation (AF).
Paulus Kirchhof, MD, Institute of Cardiovascular
Sciences, University of Birmingham, Birmingham,
United Kingdom, opened by suggesting that there is
growing evidence to support early cardioversion with
novel oral anticoagulants, including in anticoagulationnaïve patients. This includes the results of the X-VeRT
[Cappato R et al. Eur Heart J. 2014] and ENSURE [Goette
A et al. Lancet. 2016] studies, as well as data from the
EMANATE study, which was presented at the 2017 ESC
Congress.
The aim of cardioversion, similar to other rhythmcontrol therapy options, is to improve symptoms.
Whether early rhythm-control therapy has benefits
beyond earlier restoration of sinus rhythm and improvement of symptoms is currently being tested [Kirchoff P
et al. Am Heart J. 2013], but recent reports are encouraging. Cardioversion can be performed electrically or
pharmacologically. Electrical cardioversion is more
effective, but requires sedation. A combination of biphasic shocks, paddle electrodes, and an anterior-posterior
electrode position promotes success [Kirchoff P et al.
Lancet. 2002; Kirchhof P et al. Eur Heart J. 2005]. While
quicker and more effective, electrical conversion is also
accompanied by an increased risk of stroke. This can be
offset with oral anticoagulation.
Pharmacological cardioversion with antiarrhythmic
drugs (AADs), although less effective (from ~50% to
~20% depending on duration of AF) and slower than
electrical cardioversion, offers a therapeutic alternative especially in patients with shorter a duration of AF.
Short-term treatment with AADs after cardioversion is
less effective than is long-term treatment, but can prevent most recurrences of AF [Kirchhof P et al. Lancet.
2012].
Patients undergoing cardioversion without anticoagulation are at high risk of stroke [Hansen ML. Europace.
2015]. Oral anticoagulation with vitamin K antagonists
or non-vitamin K antagonist (VKA) oral anticoagulants
(NOACs) result in a marked reduction of ischaemic
strokes in patients undergoing cardioversion [Hansen
ML et al. Europace. 2015].

No OAC

OAC

40
0
20

120

150

90 120 150 180 210 240 270 300 330 360

180

210

240

270

300

330

360

Time Since Discharge in Days

AF, atrial fibrillation; DC, direct current; OAC, oral anticoagulation.
Reprinted from Hansen ML et al. Thromboembolic risk in 16,274 atrial fibrillation patients undergoing direct current cardioversion with and without oral
anticoagulant therapy. Europace. 2015; https://doi.org/10.1093/europace/
euu189. By permission of Oxford University Press on behalf of the European
Society of Cardiology.

The ESC recommends the use anticoagulants for at
least 3 weeks before cardioversion, in patients with a
transoesophageal echocardiography (TOE) detected
thrombus, and long-term after cardioversion to reduce
stroke risk. NOACs are at least as safe as VKA for stroke
prevention in patients undergoing cardioversion, and
may even reduce stroke risk relative to VKA therapy
based on recent randomised trials.
Riccardo Cappato, MD, Humanitas University,
Electrophysiology & Arrhythmia Center, Humanitas
Research Institute, Milan, Italy, discussed some of the
practical issues when anticoagulating AF patients
undergoing cardioversion.
When deciding to perform acute or elective cardioversion, the decision is guided by the timing or symptoms of AF. The choice of early or delayed elective
cardioversion will impact the number of patients effectively cardioverted and the probability of restoration
and maintenance of sinus rhythm. Data regarding the
choice of pharmacological or electrical cardioversion
is not clear cut. The decision is based on the natural
course of AF and comorbidities of the patient, as well
as logistics (availability of direct current shock system,
tradition, costs, setting, early vs delayed). The earlier
the decision the better.

medicom-publishers.com/mcr

https://doi.org/10.1093/europace/euu189 https://doi.org/10.1093/europace/euu189 http://www.medicom-publishers.com/mcr

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