Shock Energy for Electrical Cardioversion of Persistent Atrial Fibrillation

A Randomised Trial of Shock Energy for Electrical Cardioversion of Persistent Atrial Fibrillation

The goal of this clinical trial is to compare the efficacy of a maximum output shock for cardioverting atrial fibrillation between two commonly used defibrillators in New Zealand . These machines have different maximum energy outputs, and to date no head-to-head comparison cardioverting atrial fibrillation between the two has been undertaken.

The main question it aims to answer is whether either device is more likely to cardiovert patients referred for atrial fibrillation.

Participants will be randomized to undergo cardioversion with one of two defibrillators at either 200J or 360J. Participants in each arm will undergo up to three shocks at the energy-level to which they have been randomized, using a standardized procedure. For participants randomized to the lower energy level who fail to return to normal rhythm after three shocks, they will be given a fourth shock at the higher energy level.

All participants will then be asked to undertake a blood test the day following the cardioversion, and receive a follow up phone call. These are to ensure there is no difference in the safety of the procedure between the two energy levels. It is worth noting that these two components of the study (the blood test and phone call) are the only additional time commitment that is expected to be involved if you choose to participate in the study.

Study Overview

• Status: Recruiting
• Conditions: Atrial Fibrillation
• Intervention / Treatment: Device: 360J LifePak Monitor/Defibrillator; Device: 200J Philips HeartStart MRx Monitor/Defibrillator

Detailed Description

Atrial fibrillation is the world's most common arrhythmia, with an incidence that is increasing in Western countries. One-in-four adults will experience atrial fibrillation at some point in their life.

Strategies for the management of atrial fibrillation include rate control, prophylaxis against stroke, lifestyle modification, and restoration of sinus rhythm through medical or electrical cardioversion. Electrical cardioversion for the restoration of sinus rhythm was first described by Lown and colleagues in 1962, and has undergone a number of procedural advances in the intervening six decades. Chief amongst these was a transition from cardioverting using monophasic to biphasic waveforms, something unequivocally demonstrated to increase cardioversion success, with lower energy, current, and less skin and muscle damage than monophasic devices. Yet the majority of the data which continues to guide cardioversion is derived from the era of monophasic therapy.

Data from cardioversion with monophasic waveforms suggests that the use of higher initial shock energy is associated with higher first shock success, fewer shocks, and lower levels of skeletal muscle injury, with no increase in troponin to suggest greater cardiac injury. Likewise, studies of shock energy using biphasic devices have demonstrated benefit of maximum fixed shock energy. However, whilst the energy of a defibrillator remains entrenched in the descriptive vocabulary of cardioversion for atrial fibrillation, it is the flow of current across the myocardium that achieves cardioversion, and resuscitation guidelines have previously recommended a switch to the more physiologic current-based description.

Different defibrillators deliver different currents at the same energy setting based on the capacitance of the device. As such, manufacturers of defibrillators recommend different energy levels for cardioverting atrial fibrillation with some standard biphasic defibrillators (Philips HeartStart MRx Monitor/Defibrillator) unable to deliver higher than 200J energy, while some (Lifepak 15 Monitor/Defibrillator) extend to 360J. No studies have compared initial 200J vs. 360J shock energies between these devices for cardioverting persistent atrial fibrillation.

This study is a single centre randomized non-blinded study of the effectiveness of 200J vs. 360J fixed output biphasic electrical cardioversion in patients undergoing electrical cardioversion of persistent atrial fibrillation. The study hypothesis is that cardioversion with shock energy fixed to 360J delivered by a LifePak Monitor/Defibrillator is more efficacious than a 200J delivered by a Philips HeartStart MRx Monitor/Defibrillator, without worsening safety outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Allan M Plant, FRACP; Phone Number: +64274114001; Email: allanmplant@gmail.com
• Study Contact Backup: Name: Darren Hooks, FRACP; Email: darren.hooks@ccdhb.org.nz

Study Locations

• New Zealand
  • Wellington, New Zealand, 6012
    • Recruiting
    • Wellington Regional Hospital
    • Contact: Allan Plant, MBChB; Phone Number: 0274114001; Email: allanmplant@gmail.com
    • Contact: Darren Hooks, MBChB, PhD; Email: darren.hooks@ccdhb.org.nz

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age >18
• Patients undergoing either elective outpatient or non-emergent inpatient cardioversion for atrial fibrillation
• Eligible for anticoagulation
• Reliably anticoagulated for ≥three weeks prior to cardioversion, AF onset within 48hrs of cardioversion, or left atrial thrombus excluded on transoesophageal echocardiogram
• Able to consent to cardioversion, and study participation

Exclusion Criteria:

• Contraindication to anticoagulation
• Atrial flutter
• Emergent cardioversion
• Implantable cardiac device (PPM or ICD)
• Unable to consent to cardioversion and/or study participation
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 360J LifePak Monitor/Defibrillator; The standardised cardioversion protocol below performed with a 360J shock from a Lifepak Monitor/Defibrillator.; First shock with anteroposterior pad configuration; In event of failure of the above, a second shock with anterolateral pad configuration; In event of failure of the above, a third shock with anteroposterior pad configuration + manual pad pressure	Device: 360J LifePak Monitor/Defibrillator; The LifePak Monitor/Defibrillator is a commonly-used defibrillator in New Zealand hospitals for cardioverting atrial fibrillation. It delivers a biphasic waveform shock with a titratable maximum energy of 360J.
Active Comparator: 200J Philips HeartStart MRx Monitor/Defibrillator; The standardised cardioversion protocol below performed with a 200J shock from a Philips HeartStart MRx Monitor/Defibrillator.; First shock with anteroposterior pad configuration; In event of failure of the above, a second shock with anterolateral pad configuration; In event of failure of the above, a third shock with anteroposterior pad configuration + manual pad pressure; The addition of a fourth 'rescue' shock at 360J using the LifePak Monitor/Defibrillator with pads in the anteroposterior configuration in the event of the first three steps failing to cardiovert to sinus rhythm	Device: 200J Philips HeartStart MRx Monitor/Defibrillator; The Philips HeartStart MRx Monitor/Defibrillator is a commonly-used defibrillator in New Zealand hospitals for cardioverting atrial fibrillation. It delivers a biphasic waveform shock with a titratable maximum energy of 200J.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardioversion efficacy	Percentage of patients successfully cardioverted to sinus rhythm	During Procedure (1 Hour)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Shock number	Number of shocks required to cardiovert to sinus rhythm	During Procedure (1 Hour)
Cumulative energy	Total energy delivered during procedure	During Procedure (1 Hour)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety outcome: skin erythema	Proportion of patients with documented skin erythema at discharge	2 hours after procedure
Safety outcome: pain score	Average pain score on a 10 point numerical rating scale from 0 (no pain) to 10 (severe pain)	2 hours after procedure
Safety outcome: troponin elevation	Proportion of patients with a significant troponin elevation (defined as a troponin greater the ULN and ≥50% increase from baseline)	24 hours after procedure
Safety outcome: troponin change from baseline	Average change in troponin from baseline	24 hours after procedure
Safety outcome: creatine kinase change from baseline	Average change in creatinine kinase from baseline	24 hours after procedure
Safety outcome: other	Any other clinically-significant event requiring change in management (need for temporary pacing / BP support / admission due to complications)	2 hours after procedure

Collaborators and Investigators

• Sponsor: Wellington Hospital
• Investigators: Principal Investigator: Allan Plant, FRACP, Wellington Hospital

Publications and helpful links

General Publications

• ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2005 Dec 13;112(24 Suppl):IV1-203. doi: 10.1161/CIRCULATIONAHA.105.166550. Epub 2005 Nov 28. No abstract available.
• Schmidt AS, Lauridsen KG, Torp P, Bach LF, Rickers H, Lofgren B. Maximum-fixed energy shocks for cardioverting atrial fibrillation. Eur Heart J. 2020 Feb 1;41(5):626-631. doi: 10.1093/eurheartj/ehz585.
• 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.
• Staerk L, Wang B, Preis SR, Larson MG, Lubitz SA, Ellinor PT, McManus DD, Ko D, Weng LC, Lunetta KL, Frost L, Benjamin EJ, Trinquart L. Lifetime risk of atrial fibrillation according to optimal, borderline, or elevated levels of risk factors: cohort study based on longitudinal data from the Framingham Heart Study. BMJ. 2018 Apr 26;361:k1453. doi: 10.1136/bmj.k1453.
• Boos C, Thomas MD, Jones A, Clarke E, Wilbourne G, More RS. Higher energy monophasic DC cardioversion for persistent atrial fibrillation: is it time to start at 360 joules? Ann Noninvasive Electrocardiol. 2003 Apr;8(2):121-6. doi: 10.1046/j.1542-474x.2003.08205.x.
• Joglar JA, Hamdan MH, Ramaswamy K, Zagrodzky JD, Sheehan CJ, Nelson LL, Andrews TC, Page RL. Initial energy for elective external cardioversion of persistent atrial fibrillation. Am J Cardiol. 2000 Aug 1;86(3):348-50. doi: 10.1016/s0002-9149(00)00932-2.
• Koster RW, Dorian P, Chapman FW, Schmitt PW, O'Grady SG, Walker RG. A randomized trial comparing monophasic and biphasic waveform shocks for external cardioversion of atrial fibrillation. Am Heart J. 2004 May;147(5):e20. doi: 10.1016/j.ahj.2003.10.049.
• Lippi G, Sanchis-Gomar F, Cervellin G. Global epidemiology of atrial fibrillation: An increasing epidemic and public health challenge. Int J Stroke. 2021 Feb;16(2):217-221. doi: 10.1177/1747493019897870. Epub 2020 Jan 19. Erratum In: Int J Stroke. 2020 Dec;15(9):NP11-NP12. doi: 10.1177/1747493020905964.

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2025
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: May 25, 2023
• First Submitted That Met QC Criteria: June 5, 2023
• First Posted (Actual): June 15, 2023

Study Record Updates

• Last Update Posted (Actual): April 1, 2025
• Last Update Submitted That Met QC Criteria: March 25, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Atrial fibrillation; Electrical cardioversion
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Atrial Fibrillation
• Other Study ID Numbers: WRH DCCV

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes