Feasibility and safety of non fluoroscopy-cryoablation of perihisian supraventricular tachycardias guided by electroanatomical mapping

Cryoablation is an available tool for therapy for the substrate of supraventricular tachycardia (SVT) located close to the specific conduction system, due to its lower risk of atrioventricular block compared to radiofrequency. Traditionally, this ablation is guided by fluoroscopy, exposing patients and healthcare profesionals to radiation. The electroanatomic map (EAM)-guided cryoablation modality is achieved by connecting the cryoablation catheter to the channel of a standard tetrapolar catheter, which allows visualization of the catheter in the anatomic matrix in a manner similar to radiofrequency catheters, thus minimizing radiation exposure. This study compares the traditional method with an EAM-guided cryoablation modality in this setting, evaluating its efficacy, safety and efficiency. The aim of this study was to assess the feasibility, efficacy, efficiency and safety of cryoablation with minimal or no fluoroscopy in perihisian supraventricular tachycardias using the EAM system.

Single-center retrospective observational study of a cohort of 37 successive patients undergoing cryoablation of supraventricular arrhythmia with perihisian substrate between Nov-2014 and Oct-2024. The procedure was classified according to cryoablation approach by fluoroscopy or electroanatomic mapping. The mean follow-up time was 55.9 ± 34.9 months. As outcome variables, acute and long-term success, recurrence, complications, fluoroscopy and procedure times were analyzed.

Twenty nine patients (78.4%) underwent EAM-guided cryoablation and 8 patients (21.6%) fluoroscopy-guided cryoablation. In 21 of the 29 patients (72.4%) of the EAM group, cryoablation was performed with complete absence of fluoroscopy. No significant differences were found in immediate success rates (EAM 82.8%, fluoroscopy 75%, p=0.48) or long-term success (EAM 65.5%, fluoroscopy 50%, p=0.34). There were also no significant differences in recurrence rates and times (table). EAM showed a significant reduction in fluoroscopy time (EAM 3.96 ± 10.44 min; fluoroscopy 28.44 ± 30.5; p=0.001) and ablation time (EAM 68.79 ± 38.89 min, fluoroscopy 112.43 ± 47.37 min; p=0.016). There was a trend towards statistical significance for a decrease in the total procedure time (MEA 215.6 ± 45.2; fluoroscopy 245.4 ± 50.3; p = 0.117). Only 2 complications (6.9%) were observed in the EAM group related to the vascular access. However, this difference was not statistically significant (p 0.61).

Electroanatomical mapping-guided cryoablation of perihisian SVTs is feasible and, at least, as effective and safe as the traditional fluoroscopy-guided approach, with the advantage of reducing radiation exposure and optimizing procedure times. These findings suggest that electroanatomic mapping is a preferable option, especially in young patients where radiation exposure is sought to be minimized without compromising clinical outcomes.Table 1.

Characteristics and results