Operator Learning Curve with a Novel Dual-Energy Lattice-tip Ablation System.

Abstract

Background: The SPHERE Per-AF trial demonstrated non-inferiority for a primary composite effectiveness endpoint in persistent atrial fibrillation (AF) patients treated with a 9-mm, lattice-tip, pulsed field (PF)/radiofrequency (RF) system (74%) vs. conventional contact force-sensing RF (65%). While operators were highly experienced with the control, the vast majority were new to the investigational system.

Objective: To assess the learning curve using this novel system.

Methods: Patients were grouped based on the sequential procedures performed per operator. Operators who performed ≤2 investigational procedures were excluded. The composite effectiveness endpoint was freedom from acute procedural failure, repeat ablation at any time, arrhythmia recurrence, drug initiation/escalation, or cardioversion each at one year excluding a 3-month blanking period. Efficiency endpoints included "skin-to-skin" procedure time.

Results: The total cohort included 443 patients (235 investigational [31 roll-in], 208 control). Primary effectiveness in the investigational cohort improved significantly with increased procedural order. Efficacy was 65% (74/114) for the first 5 patients per operator, 75% (33/44) for patients 6-10, and 80% (60/75) for patients >10. Kaplan-Meier effectiveness estimates at one year follow-up were significantly higher in the investigational cohort after 10 procedures performed, compared to control (80% vs. 65%, p<0.05). With the investigational system, total procedure time was reduced by 25 minutes (100 vs 125) within the first 5 procedures performed (p<0.001).

Conclusion: AF ablation with a novel dual-energy, lattice-tip ablation system resulted in greater clinical efficacy compared to conventional RF after a rapid operator learning curve, with superior procedural efficiency noted from the initial procedures onward.