Pulmonary vein isolation with the novel radiofrequency balloon catheter: predictors of single-shot isolation

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Single-shot technologies have demonstrated comparable results to point-by-point ablation for pulmonary vein (PV) isolation (PVI). The novel multi-electrode radiofrequency (RF) Balloon catheter (RFB) has been developed to achieve safe and effective single-shot PVI. PURPOSE: This single-centre study aimed to evaluate ablation parameters predictors of single-shot PVI with the novel RFB. METHODS: All consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) undergoing first-time PVI with the RFB between August 2021 and November 2022 were prospectively included. Remapping was performed in all patients to confirm persistent intraprocedural PVI. Clinical, procedural and ablation parameters were systematically collected. First RF applications were categorized as follows: 1) single-shot PVI (SS-PVI), in case of PVI without acute intraprocedural reconnection and 2) non-single-shot PVI (NSS-PVI), if single-shot isolation was not obtained at first application or if isolation was followed by acute PV reconnection. RESULTS: A total of 492 first RF applications were analysed, 433 (88.1%) SS-PVI and 59 (11.9%) NSS-PVI. Overall, the mean impedance drop was 22.9 ± 5.4 Ω, and the mean temperature rise was 12.2 ± 3.3 °C. SS-PVI showed higher mean impedance drop and mean temperature rise compared to NSS-PVI (23.3 ± 5.3 Ω vs 20.1 ± 4.9 Ω, p<0.001; 12.4 ± 3.3 °C vs 10.8 ± 2.8 °C, p<0.001, respectively). SS-PVI showed higher values of mean impedance drop and temperature rise for all veins, except for the left superior PV. For the other PVs, impedance drop and temperature rise were significant predictors of SS-PVI (OR per 1 Ω increase, 1.22, 95% CI 1.13-1.32, p<0.001, and OR per 1 °C increase, 1.34, 95% CI 1.17-1.54, p<0.001, respectively). The best cut-offs to predict SS-PVI were: impedance drop >19.2 Ω (sensitivity 0.79, specificity 0.62, PPV 0.94, NPV 0.25, AUC 0.75) and temperature rise >11.1 °C (sensitivity 0.58, specificity 0.84, PPV 0.18, NPV 0.97, AUC 0.72); Figure 1. CONCLUSION: Specific cut-offs of impedance drop and temperature rise are able to predict single-shot PVI with the novel RFB and may be implemented in the procedural workflow to optimize the ablation procedure. [Figure: see text]