Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia worldwide and is associated with substantial morbidity, mortality, and healthcare utilization. Catheter ablation, most commonly pulmonary vein isolation (PVI), is an established rhythm control strategy for AF4.

Despite technological advances and the emergence of pulse field ablation (PFA), long-term AF recurrence after a first ablation procedure remains frequent, occurring in approximately 30-50% of patients5. Post-ablation follow-up strategies, including visit frequency, rhythm monitoring intensity, and Antiarrhythmic Drug management, vary widely across providers and institutions and are largely guided by subjective assessment rather than objective, science-based recurrence risk estimation6. In parallel, asymptomatic (silent) AF recurrence is exacerbated following ablation, limiting the reliability of symptom-driven follow-up7.

FOLLOW-AF is a retrospective, observational cohort study designed to validate the FollowGenius algorithm and evaluate the diagnostic performance in predicting AF recurrence based on atrial remodeling and vein isolation.

The cohort will be patients with paroxysmal or persistent AF who underwent PVI with the PFA modality.

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia worldwide and is associated with substantial morbidity, mortality, and healthcare utilization.3 Catheter ablation, most commonly pulmonary vein isolation (PVI), is an established rhythm control strategy for symptomatic AF.4 Historically, this has been achieved using radiofrequency and thermal energy. However, more recently a new energy source known as pulsed field ablation (PFA) has been introduced. As PFA is tissue selective, it preserves the function of nearby structures such as the esophagus and phrenic nerve making it safer to use. As PFA is delivered in short bursts of high energy, it is also more efficient and leads to shorter procedures.

Despite technological advances and the emergence of pulse field ablation (PFA), long-term AF recurrence after a first ablation procedure remains frequent, occurring in approximately 30-50% of patients.5 Post-ablation follow-up strategies, including visit frequency, rhythm monitoring intensity, and anticoagulation management, vary widely across providers and institutions and are largely guided by subjective assessment rather than objective, science-based recurrence risk estimation.6 In parallel, asymptomatic (silent) AF recurrence is exacerbated following ablation, limiting the reliability of symptom-driven follow-up.7

The underlying causes of AF recurrence are broadly driven by two distinct, yet complementary, mechanisms:

1. Atrial Substrate Modification (Remodeling): Many patients have pre-existing atrial myopathy or remodeling due to long-standing hypertension, heart failure, or AF itself. This "diseased substrate" is prone to initiating and sustaining new AF triggers outside the pulmonary veins. P-wave duration, a simple, non-invasive marker from the surface ECG, is a well-established surrogate for this electrical and structural remodeling.2,9,10
2. PVI Isolation (Reconnection): The primary goal of ablation is to create durable, transmural lesions to isolate the pulmonary veins. If lesions are incomplete, electrical reconnection often occurs, allowing the original AF triggers to re-initiate arrhythmia. Residual local potentials measured during the ablation procedure are a suggested marker of incomplete lesion formation, predicting non-durability.1,11,12

Pulmonary vein isolation status is acquired by measuring the intra-cardiac residual electrical activity (local potential) in the vein, after PFA application. Residual local potentials will be extracted by the PF Analyzer module of the ECGenius™ System. Isolation status is defined based on thresholds from literature.

The FollowGenius algorithm is intended to allow AF recurrence risk stratification by providing risk scores (0-100).

FOLLOW-AF is a retrospective, observational cohort study designed to validate the prediction algorithm and evaluate the diagnostic performance in predicting AF recurrence based on atrial remodeling and vein isolation.

The cohort will be patients with paroxysmal or persistent AF who underwent PVI with the PFA modality.

Inclusion Criteria:

• Age ≥ 21 years
• Paroxysmal or persistent atrial fibrillation
• Underwent pulmonary vein isolation using pulse field ablation
• Patient record with pre-/post-ablation 12-lead ECGs and intra-procedural unipolar electrograms

Exclusion Criteria:

• Incomplete patient record:

  • Lack of 12-leads ECG recording or intracardiac electrograms
  • Lack of post-procedure follow-up assessment
  • Follow-up was less than 6 months

• Cardiac recording data incomplete or not of sufficient quality

• Cardiac anatomical variation such as Left Common, or Right Accessory

Outpatient EHR