Ultra-low temperature cryoablation vs. radiofrequency ablation for the management of atrial fibrillation: long term outcomes

Abstract Background Catheter ablation is a well-established treatment for atrial fibrillation (AF), effectively reducing AF burden, improving quality of life, and decreasing cardiovascular risk. The efficacy and the safety between point-by-point radiofrequency (RF) and one-shot techniques such as cryoablation or pulsed field ablation are similar. Recently, a novel ultra-low temperature cryoablation (ULTC) has been introduced, achieving temperatures as low as -196°C versus -89°C with traditional cryoballoon ablation. This cryogenic energy can potentially create deeper, transmural lesions and thus, more durable. Purpose To compare the long-term outcomes of a novel ULTC catheter system vs RF catheter ablation for the management of paroxysmal (PAF) and persistent (PsAF) atrial fibrillation. Methods Between 2022 and 2023, 19 patients with PAF/PsAF who underwent ultra-low temperature ablation (Group A) were propensity matched in 1:1 ratio with 19 patients treated with RF ablation (Group B). Patients with previous AF ablation or a follow-up period less than 12 months were excluded from the study. Primary endpoint was defined as the freedom from a redo-AF procedure within the study period. Results Propensity score matching was performed in 1:1 ratio based on age (61.9 ± 10.6 years in group A vs 62.2 ± 9.4 years in group B, p = 0.938), sex (4 females in each group) and AF type (n=7 for PAF and n=12 for PsAF in each group) (Figure 1). Pulmonary vein isolation was successfully achieved in all patients (n=38). As for the additional lesions, there was no difference between the two groups in terms of the posterior line (n=8 in group A and group B), the roof line (n=9 in group A and group B), and the mitral annulus line (n=4 in group A and n=3 in group B, p = 0.676) (Figure 1). Mean follow-up was 23.5 ± 7.8 months for group A and 24.1 ± 8.9 months for group B (p = 0.837, Figure 1). During this period, freedom from redo-AF ablation was significantly higher in group A (n=16 patients) than in group B (n=10 patients) (p = 0.017, Figure 2). Conclusion In this single-centre retrospective study, freedom from redo-AF ablation with a novel ultra-low temperature cryoablation appears to be higher compared to the traditional radiofrequency ablation, indicating greater procedural durability beyond 12 months. Further randomised trials with larger number of patients are warranted to confirm these findings.Baseline and ablation characteristics Graphical abstract