MAX - SHOCK Clinical Trial (MAX-SHOCK)

University of Ottawa Heart Institute

Status: Enrolling

Conditions: Atrial Fibrillation; Cardioversion

Treatments: Device: biphasic defibrillator with maximum energy of 360J (® Physio-Control); Device: biphasic defibrillator with maximum energy of 200J (® Zoll)

Study type: Interventional

Funder types: Other

Identifiers

NCT06556667

CRRF 6004

Details and patient eligibility

About

Can Electrical Cardioversion (ECV) for AF be improved. It is the preferred method to restore sinus rhythm in patients with AF in whom a rhythm-control strategy is pursued.

Hypothesis:

ECV success rates will be greater with a biphasic defibrillator with maximum energy of 360J (® Physio-Control) compared to a biphasic defibrillator with maximum energy of 200J (® Zoll)

Full description

Published estimates of ECV success using modern biphasic defibrillators vary considerably but most are limited by small sample sizes. Our pre-intervention ECV success rate of 91.8% was stable over >2.5 years and is comparable to a previous study from our institute11 and to recent estimates from moderately sized studies using contemporary technology. For instance, the Euro Heart Survey on AF reported an ECV success rate of 91% in 424 patients2 and the Biphasic Energy Selection for Transthoracic cardioversion of Atrial Fibrillation (BEST AF) trial reported 89% success in 380 patients.3 The variability in starting shock energy and shock energy escalation observed at our centre prior to implementing the OAFCP is also consistent with reported practices elsewhere. A recent survey of 57 European centres found that nearly two-thirds of hospitals started with a 100 J biphasic shock for AF whereas the remaining third started with 200 J.1 Considerable differences in electrode placement were also reported in this survey with 58.7% of centres using an anterolateral position and the remainder using an anteroposterior approach.1Our investigators and others have previously shown that physicians seldom apply sufficient force even when prompted to do so and even when using handheld paddles.10,16,17 ECV practices at our institute prior to implementing the OAFCP were therefore likely representative of those at most centres.

Enrollment: 376 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Patients age > 18 years.
• Persistent atrial fibrillation.
• Scheduled for elective cardioversion at UOHI
• Patient is within the circle of care of UOHI Electrophysiology staff

Exclusion criteria

• Known left-atrial appendage thrombus.
• Contraindication to appropriate anticoagulation.
• Patient is included in another randomized clinical trial.
• Patient does not meet all of the above listed inclusion criteria.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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376 participants in 2 patient groups

200J

Active Comparator group

Description:

biphasic defibrillator with maximum energy of 200J (® Zoll)

Treatment:

Device: biphasic defibrillator with maximum energy of 200J (® Zoll)

360J

Active Comparator group

Description:

biphasic defibrillator with maximum energy of 360J (® Physio-Control)

Treatment:

Device: biphasic defibrillator with maximum energy of 360J (® Physio-Control)