Comparison of High Versus Escalating Shocks in Cardioverting Atrial Fibrillation

Not Applicable

Completed

• Conditions: Atrial Fibrillation
• Interventions: Device: High energy shock protocol; Device: Standard escalating shocks

• Registration Number: NCT02923414
• Lead Sponsor: University of Aarhus

Brief Summary

Atrial fibrillation is the most common heart rhythm disorder. For patients suffering atrial fibrillation direct current cardioversion is performed to reduce patients symptoms and prevent disease progression. The optimal energy selection for biphasic cardioversion is unknown.

We aim to investigate the efficiency and safety of a high energy shock protocol (360 J) versus a standard escalating shock protocol (125-150-200 J) in cardioversion of atrial fibrillation.

Detailed Description

The optimal energy selection for biphasic direct current (DC) cardioversion of atrial fibrillation is unknown. The energy delivered should be sufficient to achieve prompt cardioversion but without the risk of inducing any potential injury e.g. skin burns, myocardial stunning or post-cardioversion arrhythmias. The use of an escalating protocol, with a low energy initial shock, has been considered conventional practice, originally to avoid post cardioversion arrhythmias when using monophasic shocks.(1) This practice has been directly transferred to biphasic cardioversion. The European Society of Cardiology 2016 guidelines (2) and the American Heart Association/American College of Cardiology 2014 guidelines on the management of atrial fibrillation (3) do not recommend any specific energy settings, whereas the European Resuscitation Council 2010 guidelines for cardiopulmonary resuscitation (4) recommend a starting energy level of 120-200 J with subsequent escalating energy setting.

Previously, a non-escalating protocol (200 J) (5) has been found to have a significantly higher first shock success resulting in fewer shock deliveries without compromising safety compared with a low energy escalating shock protocol (100-150-200 J). Further, a study found fewer arrhythmic complications with increasing energy suggesting an 'upper limit of vulnerability'. It is well-established that biphasic shocks induce fewer post-shock arrhythmias (6), skin burns (7) and shorter periods of myocardial stunning compared with monophasic shocks.(8) Importantly, no correlation between increasing biphasic energy delivery and any complications was found in these studies. Nonetheless, the efficiency and safety of a high energy shock (360 J) biphasic protocol compared with a conventional low energy escalating protocol is unknown. Accordingly, this study aims to compare the efficiency and safety of a high energy protocol (360-360-360 J) versus a standard escalating protocol (125-150-200 J). We hypothesise that a high energy cardioversion protocol is more effective compared to standard escalating energy protocol, without compromising safety.

Study Timeline

• Study Start: 2016-09-28
• Study First Submitted: 2016-10-03
• Study First Submitted QC: 2016-10-03
• Study First Posted: 2016-10-04
• Status Verified: 2018-04
• Primary Completion: 2019-03-08
• Study Completion: 2019-03-08
• Last Update Submitted: 2019-03-20
• Last Update Posted: 2019-03-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 276

Inclusion Criteria

• >18 years of age, scheduled for cardioversion of atrial fibrillation. Patients with atrial fibrillation for ≤48 hours may be cardioverted immediately. Patients with atrial fibrillation for >48 hours will be required to have a documented weekly international normalized ratio (INR) ≥2.0 (including within 48 hours of cardioversion) or treatment with non-vitamin K oral anticoagulant for three weeks or longer. Alternatively, a transoesophageal echocardiogram documenting absence of intracardiac thrombi is accepted and cardioversion can be performed on treatment with low molecular weight heparin.

Read More

Exclusion Criteria

• Pregnancy, haemodynamically unstable atrial fibrillation, other arrhythmias than atrial fibrillation, untreated hyperthyroidism

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
High energy shocks	High energy shock protocol	Patients will be randomized to a high energy shock protocol using the energy settings: 360, 360, 360 J. All cardioversion attempts will be performed using LIFEPAK 20, Physio-Control Inc., Redmond, WA, USA
Standard escalating shocks	Standard escalating shocks	Patients will be randomized to a standard escalating shock protocol using the energy settings: 125, 150, 200 J. All cardioversion attempts will be performed using LIFEPAK 20, Physio-Control Inc., Redmond, WA, USA

Primary Outcome Measures

Name	Time	Method
Efficacy: Successful cardioversion	One minute following cardioversion	Successful cardioversion is defined as the proportion of patients in sinus rhythm one minute after cardioversion or cardioversion attempt (to a maximum of the 3 shocks in the protocol).

Secondary Outcome Measures

Name	Time	Method
Safety: Echocardiographic evaluation following cardioversion	Two hours after cardioversion	Comparing a baseline echocardiographic evaluation with an evaluation performed two after cardioversion, e.g. left ventricular function using standard echocardiographic measurements.
Efficacy: First shock success	Following first cardioversion attempt	Successful cardioversion following the first cardioversion attempt (125 J versus 360 J).
Safety: Skin-discomfort, skin burns or itching	Two hours after cardioversion	Patients self-assessment of skin discomfort and objective measurement of skin burns or itching.
Safety: Arrhythmic events and ECG-changes following cardioversion	Within four hours following cardioversion (until discharge)	Any post-cardioversion arrhythmias will be recorded using ECG-holtering four hours post cardioversion. Further ECG changes will be measured (sinus node dysfunction, atrioventricular delay, ventricular tachyarrhythmia or ventricular premature complexes, ST-segment deviations and recurrence of AF).
Safety: Troponin I level changes following cardioversion	Four hours after cardioversion	To evaluate changes in high sensitive cardiac troponin I levels between a baseline measurement before cardioversion and the level four hours following cardioversion.

Trial Locations

Locations (1)

Randers Regional Hospital; 🇩🇰 Randers, Denmark