Clinical trial NCT02923414: Comparison of High Versus Escalating Shocks in Cardioverting Atrial Fibrillation
Official title: The Efficiency and Safety of a High Energy Shock Protocol (360-360-360 J) Versus a Standard Escalating Energy Shock Protocol (125-150-200 J) in Cardioverting Atrial Fibrillation
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Atrial Fibrillation
Keywords: Cardioversion
Lead sponsor: University of Aarhus
Sponsor class: OTHER
Collaborators: name: Randers Regional Hospital
First posted: 2016-10-04
Enrollment: 276
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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.

Exclusion Criteria:

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

Primary outcomes:
measure: Efficacy: Successful cardioversion
timeFrame: One minute following cardioversion
Secondary outcomes:
measure: Efficacy: First shock success
timeFrame: Following first cardioversion attempt
measure: Safety: Arrhythmic events and ECG-changes following cardioversion
timeFrame: Within four hours following cardioversion (until discharge)
measure: Safety: Skin-discomfort, skin burns or itching
timeFrame: Two hours after cardioversion
measure: Safety: Troponin I level changes following cardioversion
timeFrame: Four hours after cardioversion
measure: Safety: Echocardiographic evaluation following cardioversion
timeFrame: Two hours after cardioversion
Other outcomes:
Locations:
city: Randers
country: Denmark
facility: Randers Regional Hospital
Study officials:
affiliation: Randers Regional Hospital
name: Bo Løfgren, MD, PhD
role: STUDY_DIRECTOR
affiliation: Randers Regional Hospital
name: Anders S Schmidt, MB
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lown B. Electrical reversion of cardiac arrhythmias. Br Heart J. 1967 Jul;29(4):469-89. doi: 10.1136/hrt.29.4.469. No abstract available.
citation: Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, Castella M, Diener HC, Heidbuchel H, Hendriks J, Hindricks G, Manolis AS, Oldgren J, Popescu BA, Schotten U, Van Putte B, Vardas P; ESC Scientific Document Group. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016 Oct 7;37(38):2893-2962. doi: 10.1093/eurheartj/ehw210. Epub 2016 Aug 27. No abstract available.
citation: January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr, Conti JB, Ellinor PT, Ezekowitz MD, Field ME, Murray KT, Sacco RL, Stevenson WG, Tchou PJ, Tracy CM, Yancy CW; ACC/AHA Task Force Members. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the Heart Rhythm Society. Circulation. 2014 Dec 2;130(23):e199-267. doi: 10.1161/CIR.0000000000000041. Epub 2014 Mar 28. No abstract available.
citation: Deakin CD, Nolan JP, Sunde K, Koster RW. European Resuscitation Council Guidelines for Resuscitation 2010 Section 3. Electrical therapies: automated external defibrillators, defibrillation, cardioversion and pacing. Resuscitation. 2010 Oct;81(10):1293-304. doi: 10.1016/j.resuscitation.2010.08.008. No abstract available.
citation: Glover BM, Walsh SJ, McCann CJ, Moore MJ, Manoharan G, Dalzell GW, McAllister A, McClements B, McEneaney DJ, Trouton TG, Mathew TP, Adgey AA. Biphasic energy selection for transthoracic cardioversion of atrial fibrillation. The BEST AF Trial. Heart. 2008 Jul;94(7):884-7. doi: 10.1136/hrt.2007.120782. Epub 2007 Jun 25.
citation: Ambler JJ, Deakin CD. A randomized controlled trial of efficacy and ST change following use of the Welch-Allyn MRL PIC biphasic waveform versus damped sine monophasic waveform for external DC cardioversion. Resuscitation. 2006 Nov;71(2):146-51. doi: 10.1016/j.resuscitation.2006.03.017. Epub 2006 Sep 20.
citation: Page RL, Kerber RE, Russell JK, Trouton T, Waktare J, Gallik D, Olgin JE, Ricard P, Dalzell GW, Reddy R, Lazzara R, Lee K, Carlson M, Halperin B, Bardy GH; BiCard Investigators. Biphasic versus monophasic shock waveform for conversion of atrial fibrillation: the results of an international randomized, double-blind multicenter trial. J Am Coll Cardiol. 2002 Jun 19;39(12):1956-63. doi: 10.1016/s0735-1097(02)01898-3.
citation: Deakin CD, Ambler JJ. Post-shock myocardial stunning: a prospective randomised double-blind comparison of monophasic and biphasic waveforms. Resuscitation. 2006 Mar;68(3):329-33. doi: 10.1016/j.resuscitation.2005.07.021. Epub 2005 Dec 27.