Fluoroless vs. conventional catheter ablation of supraventricular tachycardia - retrospective single-centre analysis
Authors: Prepolec I , Pasara V , Nekic A , Katic Z , Kardum D , Pezo Nikolic B , Puljevic D , Milicic D , Velagic V 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Radiofrequency (RF) catheter ablation of supraventricular tachycardia (SVT) is a gold-standard therapy that offers excellent results. Conventional approach using fluoroscopy has been challenged by the increasing use of electroanatomical mapping (EAM) systems and intracardiac echosonography (ICE) which eliminate the radiation hazard for the patient and medical personnel. They offer good results without compromising safety or efficacy but also require further research. (1, 2) Their widespread use is limited by their cost but is steadily increasing.

Purpose
To compare the acute outcomes of fluoroless SVT ablation to those of conventional procedures since widespread introduction of this novel technology in our institution.

Methods
Data about patients with AV-node reentry tachycardia (AVNRT), atrio-ventricular reentry tachycardia (AVRT), atrial tachycardia and atrial flutter (AFL) who were treated with ablation were retrospectively collected using hospital medical records. 80 consecutive patients who underwent fluoroless SVT ablation formed the fluoroless (FL) group. Last 80 patients who previously underwent conventional SVT ablation using fluoroscopy served as a control group. Two different EAM systems were used in the FL group (Abbot Ensite and Biosense Webster CARTO). All procedures were performed by 3 different experienced operators.

Results
The fluoroless and control group were similar regarding age, sex and comorbidities. Approximately half of all patients in both groups suffered from AVNRT. AVRT was more common in the FL group and AFL in the control group (23.4% vs. 10.0% and 20.8% vs. 37.5% respectively). This was responsible for the difference in the use of ICE and need for transseptal puncture between the groups. Detailed group characteristics are shown in Table 1. Procedure duration was similar in both groups (58.0 ± 25.5 min vs. 63.9 ± 25.3 min in FL and control group respectively, p=0.12). Ablation time, calculated as duration of RF energy delivery, tended to be shorter in the FL group (396 ± 44 vs. 575 ± 636 s) but failed to reach the level of statistical significance (p=0.06). Acute success, defined as non-inducibility of arrhythmia or, in case of AFL, cavotricuspid isthmus conduction block, was achieved in 98.8% and 97.5% of cases in FL and control group respectively. There were no cross-overs from FL group to fluoroscopy. In the control group, mean fluoroscopy duration was 9.7 ± 7.5 min and radiation dose 14.6 ± 21.6 mGy. One steam pop occurred in the FL group but the patient suffered no acute or chronic consequences. There were no other complications.

Conclusion
Technologies for fluoroless SVT ablation have been widely implemented in our institution with very good acute results and safety profile that is non-inferior to conventional approach. By eliminating risks inherent to fluoroscopy they could be beneficial for patients and physicians likewise. Follow-up data are needed to confirm these results.