Safety, efficiency and efficacy of catheter ablation in paroxysmal atrial fibrillation: insights from the Abbott United Registry for Ablation (AURA) registry
M A R Desouki, J A Y Sengupta, E M I L Y Halvorson, E V A N Walser-Kuntz, D Stewart, M Kapphahn-Bergs, K E R O Abdelsayed, A L I Bahbah, T E S F A Ergando, D A W N Witt, E D W I N Zishiri, J Zakaib, D A N I E L Melby, J C MooreAbstract
Introduction
The Sphere-9 catheter is a dual energy [pulsed field (PF) and radiofrequency (RF)] ablation catheter for the management of persistent atrial fibrillation. It has not been evaluated for treatment of paroxysmal atrial fibrillation (PAF). Specifically, no prior study has evaluated the short-term procedural safety, efficiency, and atrial arrythmia recurrence rate with the use of the Sphere-9 catheter for the treatment of this cohort as compared to the Farapulse PF catheter and the Biosense Webster RF catheters in patients with PAF.
Methods
This retrospective cohort study included patients who had de novo or repeat ablations for PAF between October 2024 and June 2025 at the our Heart Institute in our AURA Registry. Our primary endpoints were procedural safety and efficiency. Our secondary endpoint was recurrence of atrial arrhythmia within 90 days after the procedure. Recurrence was defined as events requiring cardioversion or EKG-documented recurrence that led to an increase in anti-arrhythmic drug dose within the first three months, by retrospective chart review. Procedural efficacy was defined by the ability to achieve a persistent block across the relevant isthmus, to render PAF non-inducible, or to acutely terminate PAF.
Results
Our cohort consisted of 139 patients, with a median age of 66 years (58 -72), 64% were male and 96% Caucasian. The Sphere-9 catheter was associated with a procedural efficacy rate of 100%, which was higher than that of Farapulse (91%) and RF (84%) (p value = 0.006). The median procedural time with the Sphere-9 catheter was 84 minutes [77, 97], compared to Farapulse at 106 minutes [91, 126] and RF at 106 minutes [85, 139] (p < 0.001). In the Farapulse group, fluoroscopy time was significantly longer at 17 minutes [14, 20] compared to RF at 1 minute [0, 3] and Sphere-9 at 3 minutes [0,5] (p value < 0.001).
Similarly, the fluoroscopy dose was higher with Farapulse, measuring 52 mGy [19, 175], compared to RF at 1 mGy [0, 9] and Sphere-9 at 2 mGy [0, 9] (p-value < 0.001) (Table.1).
Within the first 30 days post-procedure, there were fewer major adverse events associated with the Sphere-9 catheter compared to the other two catheters. There was no significant difference in atrial arrhythmia recurrence rates within the first three months among the three catheter modalities (RF: 5/44, Farapulse: 6/45, Affera: 3/50, p = 0.48). (Table 2)
Conclusion
Ablation of PAF with the Sphere-9 catheter showed higher procedural success rates and shorter procedural times. Its safety profile was comparable to that of Farapulse and RF catheters in our cohort. Future studies should evaluate longer term efficacy and safety in a larger cohort.