Comparative Intra-procedural Evaluation of Farapulse and FARAWAVE Nav Catheters

The FARAPULSE PFA catheter (Boston Scientific), a first-generation Pulsed Field Ablation (PFA) tool, has demonstrated good performance in isolating pulmonary veins (PV) as standard of care for atrial fibrillation (AF) ablation. Several centers, including ours, utilize pre-procedural CT or cardiac magnetic resonance (CMR) imaging to evaluate individual pulmonary vein anatomy and optimize ablation planning. However, these imaging modalities are costly. Additionally, CT imaging exposes patients to radiation, and both CT and CMR add significant logistical challenges to the procedural workflow.

The FARAWAVE Nav PFA catheter, a second-generation device, integrates magnetic navigation capabilities with detailed mapping and PFA therapy into a single device. This system leverages the FARAVIEW Software Module, offering tailored mapping solutions visualized on the FARAPULSE PFA System, including the creation of voltage and activation maps. Key technical enhancements of the FARAWAVE Nav PFA catheter include: Field Tag Technology: Field tagging estimates field volume and indicates energy delivery locations. Tags confirm overlap between applications, ensuring comprehensive PV isolation. Voltage/Activation Maps: Mapping data enhances procedure precision, allowing visualization of electrical activation and PV anatomy without reliance on pre-ablation CT imaging. These features address the limitations of the first-generation FARAPULSE catheter and have the potential to enhance procedural accuracy and the durability of pulmonary vein isolation. Moreover, they may eliminate the need for pre-procedural CT or CMR, thereby reducing costs and minimizing patient exposure to radiation.

Our center, like several others, has used the first-generation catheter in routine clinical practice for over a year. More recently, we have also started using the second-generation catheter as part of standard clinical care. Currently, the two devices are used interchangeably, depending on logistical availability, particularly the presence of specialized technicians from Boston Scientific, who are required for the proper operation of the second-generation catheter.

Our study evaluates whether the FARAWAVE Nav catheter, without pre-ablation CT, allows to reduce fluoroscopy time and total patient radiation load as compared to conventional workflow with FARAPULSE catheter. Furthermore, procedural time, costs, number of PFA applications and AF recurrence free survival will be assessed.

Inclusion Criteria

• Atrial fibrillation (AF) documented on a 12-lead ECG, Holter monitor, or implantable cardiac device.
• Candidate for ablation according to current atrial fibrillation guidelines.
• Age ≥18 years at the time of informed consent.
• Signed informed consent obtained.

Exclusion Criteria

• Previous left atrial ablation or left atrial surgery.
• Presence of intracardiac thrombus.
• Persistent atrial fibrillation lasting >3 years.
• Severe mitral regurgitation or moderate-to-severe mitral stenosis.
• Pregnancy (all women under 50 years undergo an HCG blood test prior to inclusion to exclude pregnancy).

Primary Endpoint

1. Fluoroscopy Time (measured in minutes)

Secondary Endpoints 2.1 Total Patient Radiation Load 2.2 Procedural Costs 2.3 Procedure Time 2.4 Left Atrial Dwelling Time 2.5 Fluoroscopy Time After Transseptal Puncture 2.6 Number of PFA Applications 2.7 AF Recurrence-Free Survival 2.8 AF Burden (in Patients with implantable loop recorder) 2.9 AF Burden (All Patients)

Randomization: 58 Patients will be randomized 1:1 to:

1. FARAPULSE + pre-ablation CT (Control Group, n=29).
2. FARAWAVE Nav without pre-ablation CT (Intervention Group, n=29). Randomization will be performed using stratified allocation based on Atrial Fibrillation pattern (paroxysmal vs. persistent AF) in a 1:1 fashion.

Intraprocedural fluoroscopy time will be collected at the time of AF ablation procedure.

To determine the required sample size for this study, we performed calculations based on previous studies, the expected fluoroscopy time are:

Control Group: Mean fluoroscopy time = 12 minutes, SD = 8 minutes [doi.org/10.1161/CIRCULATIONAHA.123.064959] Intervention Group: Mean fluoroscopy time = 7 minutes, SD = 7 minutes [doi:10.1161/CIRCEP.122.011780] Given these assumptions, that correspond to an effect size (Cohen'd) of 0.80, a power of 80% and a 2-sided alpha of 5%, we will need to enrol 52 patients (26 per group). To ensure the study remains adequately powered despite potential dropouts, protocol deviations, or missing data, an additional 10% buffer may be considered, bringing the total recommended enrolment to 58 patients per group. Calculations have been performed using the Stata software (release 18.5, StataCorp, College Station, TX, USA).