Lattice vs Pentaspline Comparative Evaluation in Persistent AF

Pulsed-field ablation is increasingly used for pulmonary vein isolation in patients with atrial fibrillation. However, the comparative efficacy, safety, and procedural efficiency of the Sphere-9 lattice-tip catheter and the FARAPULSE pentaspline catheter have not been established in patients with persistent atrial fibrillation. Furthermore, outcomes following a pulmonary-vein-isolation-only strategy in this population have not been adequately evaluated using continuous rhythm monitoring.

LANCE-AF is a prospective, multicenter, multinational, randomized, non-inferiority trial enrolling patients with symptomatic persistent atrial fibrillation. Eligible participants must have continuous atrial fibrillation lasting more than 7 but less than 365 days. Participants will be randomized in a 1:1 ratio to pulmonary vein isolation using either the Sphere-9 lattice-tip catheter or the FARAPULSE pentaspline catheter.

All participants will undergo pulmonary vein isolation as the sole permitted atrial fibrillation ablation lesion set. Empirical left atrial substrate modification will not be permitted. Participants presenting in atrial fibrillation or another non-sinus rhythm will undergo cardioversion to sinus rhythm before ablation. Acute procedural success will be confirmed by demonstration of entrance block in all treated pulmonary veins at the end of the procedure. Cavotricuspid isthmus ablation is the only permitted non-pulmonary-vein lesion set and may be performed only in participants with documented typical atrial flutter. Catheter use for cavotricuspid isthmus ablation will follow the treatment-group-specific requirements defined in the protocol.

An insertable cardiac rhythm monitor will be implanted during the index procedure and will provide continuous rhythm monitoring throughout the study, with a 2-month postablation blanking period.

Participants will be followed for 12 months after the index ablation procedure, with continuous rhythm monitoring provided by the insertable cardiac monitor. Scheduled remote assessments will be performed at 30 days, at the end of the 2-month blanking period, and at 6 months. An in-person assessment will be performed at 12 months. Unscheduled assessments will be performed as clinically indicated.

The primary endpoint combines acute ablation success with freedom from treatment failure through 12 months. Treatment failure is defined as the occurrence of any of the following: insertable-cardiac-monitor-documented atrial fibrillation, atrial flutter, or atrial tachycardia lasting at least 6 minutes; electrical or pharmacological cardioversion for an atrial arrhythmia; repeat atrial ablation; or protocol-defined use of a Class I or Class III antiarrhythmic drug. These events are assessed after the 2-month blanking period, except that any amiodarone use after the index ablation, including during the blanking period, constitutes treatment failure.

Secondary outcomes include a composite of prespecified device- and procedure-related adverse events, postablation atrial fibrillation/atrial flutter/atrial tachycardia burden, the proportion of participants with an atrial arrhythmia burden below 0.1%, the duration of the longest atrial arrhythmia episode, time to first atrial arrhythmia episode, changes in quality of life assessed using the AFEQT and EQ-5D-5L questionnaires, total procedure time, left atrial dwell time, and fluoroscopy time and dose.

All insertable-cardiac-monitor-flagged episodes contributing to the efficacy endpoints will be reviewed by two independent adjudicators blinded to treatment assignment and catheter type. Disagreements will be referred to a third blinded adjudicator, with the majority determination considered final. Prespecified safety events will be reviewed by an independent Clinical Events Committee. An independent Data and Safety Monitoring Board will provide external safety oversight. The primary non-inferiority analysis will be performed in both the Full Analysis Set and Per-Protocol populations using a non-inferiority margin of 10 percentage points.

Inclusion criteria

• Age ≥ 18 years
• Symptomatic AF (EHRA symptom class ≥ II)
• Documented persistent AF (continuous AF for > 7 days and < 365 days), confirmed within 180 days of enrollment by either a 24-hour Holter recording showing continuous AF, or two ECGs from any regulatory-cleared rhythm monitoring device, taken at least 7 days apart, showing continuous AF
• Patients considered eligible for catheter ablation (either refractory/intolerant to ≥1 Class I/III AAD or presenting for first-line ablation per clinical discretion)
• Willing and capable of undergoing insertable loop recorder (ILR) implantation at the index procedure and maintaining the conditions required for automatic remote transmission throughout the 12-month study period
• Willing and capable of participating in all follow-up assessments and testing associated with this clinical investigation at an approved clinical investigational center

Exclusion criteria

Anatomical and procedural exclusions

• Previous catheter or surgical ablation, except right-sided atrial ablation for supraventricular tachycardia or cavotricuspid isthmus ablation for atrial flutter
• Severe left atrial enlargement: left atrial anteroposterior diameter ≥55 mm or LAVI >50 mL/m2
• Left atrial or left atrial appendage (LA/LAA) thrombus
• Prior pulmonary vein intervention, pulmonary vein stenting, or known severe pulmonary vein stenosis
• Presence of an interatrial baffle, ASD/PFO closure device, or surgical patch that, in the investigator's judgment, precludes safe transseptal access Cardiovascular exclusions
• New York Heart Association (NYHA) functional class III or IV
• Recent acute coronary syndrome, coronary revascularization, cardiac surgery, stroke, or transient ischemic attack within the preceding 90 days
• Severe valvular heart disease or prosthetic heart valve/annuloplasty ring
• History of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF).
• Atrial fibrillation secondary to reversible non-cardiac causes. Other exclusions
• Presence of an insertable cardiac device (pacemaker, ICD, CRT, or pre-existing non-study ILR)
• Contraindication or intolerance to therapeutic systemic anticoagulation
• Documented baseline hemi-diaphragmatic paresis or paralysis
• Inability, unwillingness, or anatomical contraindication (e.g., implant-site skin or soft-tissue pathology, prior radiation, or chest-wall deformity) to undergo ILR implantation
• Severe renal impairment: eGFR<30 mL/min/1.73 m2 or current/prior renal replacement therapy
• Pregnancy or planned pregnancy during the 12-month trial window
• Inability or unwillingness to provide informed consent or complete 12 months of trial follow-up