Clinical Arrhythmias
Practical Implementation of Anticoagulation Strategy for Patients Undergoing Cardioversion of Atrial Fibrillation Andreas Goette 1 and Hein Heidbuchel 2 1. St Vincenz Hospital Paderborn, Paderborn, Germany; 2. Antwerp University Hospital, University of Antwerp, Antwerp, Belgium
Abstract Anticoagulation is routinely prescribed to patients with persistent AF before cardioversion to reduce the risk of thromboembolic events. As direct oral anticoagulants (DOACs) have a rapid onset of action, a consistent anticoagulant effect, if taken correctly, and do not need monitoring or dose adjustments, there is considerable interest in their use for patients with AF undergoing cardioversion. Post-hoc analyses show that DOACs are safe to use prior to and following cardioversion. In addition, two randomised controlled trials, X-VeRT and ENSURE-AF, have demonstrated the efficacy and safety of the DOACs rivaroxaban and edoxaban, respectively, in this setting. The use of DOACs allows cardioversions to be performed promptly and reduces the number of cancelled procedures compared with the use of warfarin.
Keywords Atrial fibrillation, cardioversion, anticoagulation, direct oral anticoagulants Acknowledgement: Medical Media Communications (Scientific) Ltd provided medical writing and editing support to the authors, funded by Daiichi Sankyo. Disclosure: Professor Goette has received speaker fees from Astra Zeneca, Berlin Chemie, Boehringer Ingelheim, Bayer Healthcare, BMS / Pfizer and Daiichi-Sankyo. Professor Heidbuchel is coordinating clinical investigator for the Biotronik-sponsored EuroEco study on health-economics of remote device monitoring, has been a member of the scientific advisory boards and/or lecturer for Boehringer-Ingelheim, Bayer, Bristol-Myers Squibb, Pfizer, Daiichi-Sankyo and Cardiome, received travel support from St. Jude Medical, and received unconditional research grants through the University of Hasselt from Bayer and through the University of Antwerp from Medtronic, Boston Scientific and Bracco Imaging Europe. Submitted: 6 February 2017 Accepted: 12 May 2017 Citation: Arrhythmia & Electrophysiology Review 2017;6(2):50–4. DOI: 10.15420/aer.2017:3:2 Correspondence: Professor H Heidbuchel, University Hospital and University of Antwerp, Antwerp, Belgium. E: heinheid@gmail.com
AF is the most common sustained cardiac arrhythmia and poses a significant public health challenge.1 In cases of AF, if sinus rhythm does not spontaneously return, cardioversion may be needed to alleviate symptoms and to improve cardiac performance.2 This may be performed by pharmacological methods, i.e. the administration of antiarrhythmic drugs, which is the preferred strategy in recent-onset AF, or by direct current electrical cardioversion, which is preferred in prolonged AF.2 The latter is more effective than pharmacological cardioversion, especially in persistent AF, although it requires anaesthesia and well-trained staff.2 A recent European survey found that the use of cardioversion in patients with AF is increasing.3 However, cardioversion itself carries an inherent risk of thromboembolic complications in AF, 4 due to the possible embolisation of pre-existing thrombus from the atrial appendage. 5 In this setting, the process of thrombogenic endocardial remodelling appears to be of importance. In addition, the process of cardioversion may promote new thrombus formation due to transient atrial dysfunction (‘stunning’), which is related to the duration of AF rather than the mode of cardioversion. 6,7 In particular, comorbidities such as heart failure, hypertension or ageing induce a thrombogenic endocardial remodelling that persists even after restoration of sinus rhythm (see Figure 1).8 This increased risk has led to recommendations for the use of anticoagulation before and after cardioversion. Without adequate anticoagulation, the risk of thromboembolism associated with cardioversion is 5–7 %.9 The use of prophylactic anticoagulation can reduce this risk to <1 %.10–12 Historically, the standard therapy for AF has been warfarin, but in recent years,
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the direct oral anticoagulants (DOACs) apixaban, dabigatran, edoxaban and rivaroxaban have been approved for the prevention of stroke in patients with AF, after demonstrating non-inferiority to warfarin in clinical trials.13–16 Furthermore, clinical data indicate that patients receiving DOAC therapy as an alternative to warfarin can be safely cardioverted.17–19 In this article we aim to discuss the guidelines for the use of anticoagulation in cardioversion and review the clinical evidence in favour of the use of DOACs in this indication.
Guidelines and Recommendations on the Use of Anticoagulants in Cardioversion For patients undergoing cardioversion it is important to consider duration of AF and prior anticoagulation.20 The 2016 European Society of Cardiology (ESC) guidelines on cardioversion state that patients who have been in AF for longer than 48 hours should start OAC therapy at least 3 weeks before cardioversion and continue for 4 weeks afterwards (in those without a need for long-term anticoagulation). If transoesophageal echocardiography (TOE) is available and acceptable to the patient, it may be used to exclude the majority of left atrial thrombi (which would preclude the procedure), allowing immediate cardioversion shortly after the start of anticoagulation, but without precluding the need for ≥4 weeks treatment afterwards. OAC therapy should be continued indefinitely in patients at increased risk of stroke. When cardioverting AF of ≤48 hours in an anticoagulation-näive patient, the guidelines do not formally advise pre-treatment with OAC and/or TOE, but advise clinicians to follow institutional practice of administering heparin or low molecular weight heparin (LMWH) with/ without TOE before cardioversion.
© RADCLIFFE CARDIOLOGY 2017