Cerebral Microembolization During Pulmonary Vein Isolation: Comparison of Different Pulsed Field Ablation Systems

This study is designed as a prospective, randomized, parallel-group interventional trial conducted at Clinical Hospital Dubrava, Zagreb, Croatia and University Hospital Center Sisters of Charity, Zagreb, Croatia. The study will include adult patients with paroxysmal or persistent atrial fibrillation who have a clinical indication for catheter ablation with pulmonary vein isolation.

Eligible patients will be randomized using a computer-generated randomization sequence to undergo pulmonary vein isolation with one of the following pulsed field ablation systems: PulseSelect, Varipulse, Farapulse, Sphere-9, or Sphere-360. All procedures will be performed according to standard clinical practice, with continuous periprocedural anticoagulation in accordance with current guidelines.

Cerebral microembolization will be assessed using transcranial Doppler. The examination will be performed immediately before the ablation procedure and repeated after the procedure. The presence and number of microembolic signals will be recorded. This will allow assessment of changes in microembolic signal burden within each group and comparison of these changes between different pulsed field ablation systems.

Demographic, clinical, and procedural data will be collected, including age, sex, type of atrial fibrillation, comorbidities, procedure duration, number of ablation applications, and procedural complications. The study will also record procedure-related clinical neurological events.

The primary outcome will be the difference in the change in the number of microembolic signals before and after the procedure, expressed as ΔMES, between the different pulsed field ablation systems. Secondary outcomes will include within-group changes in microembolic signal burden, incidence of new microembolic signals after the procedure, association between procedural parameters and ΔMES, and occurrence of procedure-related neurological events.

Inclusion criteria

• Age 18 years or older
• Paroxysmal or persistent atrial fibrillation
• Indication for catheter ablation with pulmonary vein isolation
• Feasibility of transcranial Doppler assessment
• Signed informed consent

Exclusion criteria

• Recent stroke or transient ischemic attack
• Significant cerebrovascular disease preventing reliable transcranial Doppler assessment
• Severe valvular or structural heart disease
• Pregnancy or breastfeeding
• Inability to receive anticoagulation