What is pulsed field ablation for treating arrhythmias?

Pulsed Field Ablation for Treating Arrhythmias

Pulsed field ablation (PFA) is a novel, non-thermal ablation modality that uses short-duration, high-voltage electrical pulses to create microscopic pores in cell membranes (electroporation), showing remarkable tissue selectivity for myocardium while sparing surrounding structures, making it a promising advancement in the treatment of cardiac arrhythmias, particularly atrial fibrillation. 1

Mechanism of Action and Key Features

• PFA works through irreversible electroporation, creating microscopic pores in cardiac cell membranes that lead to cell death without thermal injury 1
• Unlike traditional thermal ablation methods (radiofrequency and cryoablation), PFA demonstrates tissue selectivity, preferentially affecting myocardial tissue while relatively sparing critical structures like the esophagus, phrenic nerves, pulmonary veins, and coronary arteries 2
• PFA effectiveness depends on electrode proximity to target tissue but does not necessarily require direct contact, which may simplify the procedure compared to contact-dependent thermal ablation 2
• The procedure can be performed very rapidly (seconds per application), potentially reducing overall procedure times to under one hour 2

Clinical Evidence and Effectiveness

• The PULSED AF pivotal trial demonstrated PFA's effectiveness at 1 year in 66.2% of patients with paroxysmal AF and 55.1% of patients with persistent AF 3
• PFA has shown promising acute data on pulmonary vein isolation with satisfactory 1-year clinical follow-up for at least one platform 1
• PFA has demonstrated effectiveness consistent with established ablation technologies while using novel irreversible electroporation energy to treat patients with AF 3
• Current guidelines recommend catheter ablation as a first-line option within a shared decision-making rhythm control strategy in patients with paroxysmal AF to reduce symptoms, recurrence, and progression of AF 4

Safety Profile

• The PULSED AF trial reported a remarkably low primary safety adverse event rate of only 0.7% in both paroxysmal and persistent AF cohorts 3
• PFA has demonstrated an exceptionally low rate of complications typically associated with thermal ablation methods, including:
  • Minimal risk of esophageal injury 1
  • Reduced risk of pulmonary vein stenosis 1
  • Low incidence of phrenic nerve palsy 1
• This improved safety profile may result from PFA's tissue specificity, creating a wider therapeutic range compared to thermal ablation technologies 2

Current Applications and Indications

• PFA is primarily being used for pulmonary vein isolation in the treatment of atrial fibrillation 2
• According to current guidelines, catheter ablation (which would include PFA) is recommended in patients with paroxysmal or persistent AF who are resistant or intolerant to antiarrhythmic drug therapy 4
• Catheter ablation is also recommended for patients with AF and heart failure with reduced ejection fraction (HFrEF) who have a high probability of tachycardia-induced cardiomyopathy 4
• Research efforts are expanding to develop focal PFA catheters for treating ventricular arrhythmias 1

Future Perspectives

• PFA technology continues to evolve with multiple platforms in clinical development 1
• Ongoing research is focusing on improving our biophysical understanding of PFA for clinical cardiac applications 5
• PFA may eventually serve as an alternative energy source to thermal ablation modalities for treating various arrhythmias beyond atrial fibrillation 5
• Prospective randomized trials are currently underway to confirm the promising efficacy and safety findings from early clinical studies 6

Procedural Considerations

• As with other catheter ablation procedures, patients undergoing PFA for AF should receive oral anticoagulation at least 3 weeks prior to the procedure 4
• Uninterrupted oral anticoagulation is recommended during the procedure to prevent peri-procedural ischemic stroke and thromboembolism 4
• Continuation of oral anticoagulation is recommended for at least 2 months after AF ablation in all patients, regardless of rhythm outcome or CHA2DS2-VA score 4
• Long-term anticoagulation decisions should be based on the patient's CHA2DS2-VA score, not the perceived success of the ablation procedure 4