Minimal fluoroscopy approach in current clinical practice with a novel ablation technology for supraventricular tachycardia: a large multicenter experience from an Italian registry
Authors: Anselmino M , Cauti F.M , Piro A , Di Belardino N , Scaglione M , Pecora D , Rossi L , Di Cori A , Tola G , Pedretti S , Mantovan R , Solimene F , Rossi P , Iaia L , Bianchi S 
Published: November 2020

Abstract

Background
Electrophysiological studies and ablation procedures expose both physicians and patients to a large amount of radiation. Most of 3-D mapping systems provide improved tracking of catheters, possibly allowing relevant reductions in radiation exposure. No data exists on the ability of the Rhythmia mapping system to minimize fluoroscopy time and dose.

Purpose
To report preliminary data on feasibility and safety of a minimal fluoroscopic approach using the Rhythmia mapping system in supraventricular tachycardia (SVT) procedures.

Methods
Consecutive patients indicated for arrhythmia ablation were enrolled in the CHARISMA study at 12 centers. For our purpose consecutive right-side procedures performed through a minimal fluoroscopy approach with the Rhythmia mapping system were analyzed. A 3D geometry of chambers of interest was reconstructed on the basis of the electroanatomic information taken from the mapping system. Fluoroscopy was used only if deemed necessary.

Results
This analysis included 266 patients (mean age = 57±17 years, 57% male) undergoing SVT procedures (120 AVNRT, 91 AFL, 32 AP, 11 AT and 12 other right atrial procedures). In all cases, diagnostic EP and ablation catheters were positioned using a low fluoroscopic electroanatomic guided approach. The mean fluoroscopy time needed for each procedure was 55±128 s. The median reconstructed RA volume was 92 [63–131] ml in a median mapping time of 11 [7–17] min. The median number of radiofrequency ablations to terminate each arrhythmia was 6 [3–12] (total RF delivery time of 291 [180–505] s). Sixty-five percent of the procedures (n=174) were completed with less than 10 s of fluoroscopy. Low fluoroscopy approach with less than 10 s (minimal fluoroscopy approach) was most frequently obtained in case of AVNRT (91, 76%) compared to other arrhythmias' ablation (83, 57%, p=0.001) Achievement of a minimal fluoroscopic approach was not affected by operator's experience (65% vs 66%, p=1.00, respectively within physician with more or less of 10 years of active practice), whereas it was affected by presence of a fellow in training during the procedure (72% without fellow vs 26% with fellow, p&lt;0.0001). A 100% rate of acute success was observed, and no procedure-related complications occurred. At multivariate logistic regression analysis adjusted for baseline confounders, both the total number of RF ablations (OR: 0.93 (95% CI:0.88 to 0.96; p=0.0053) and the presence of a fellow in training during the procedure (OR: 0.29; 95% CI: 0.1 to 0.87; p=0.0278) had an inverse association to the achievement of a minimal fluoroscopic approach.

Conclusions
In our preliminary experience, arrhythmias' ablation through minimal fluoroscopy approach with the use of a novel ablation technology seems to be safe, feasible, and effective in common right atrial arrhythmias. Use of fluoroscopy can be dramatically reduced in most cases, without any reduction of the safety and acute effectiveness profile.

Funding Acknowledgement
Type of funding source: None