P2836Role of pre-procedural CT-imaging on catheter ablation in patients with atrial fibrillation: procedural outcomes and radiological exposure
Authors: Di Cori A , Zucchelli G , Faggioni L , Segreti L , Barletta V , De Lucia R , Viani S , Paperini L , Della Tommasina V , Parollo M , Cellamaro T , Branchitta G , Soldati E , Caramella D , Bongiorni M G 
Published: October 2019

Abstract

Introduction
Cardiac computerized tomography (CT) is commonly used to study left atrial (LA) and pulmonary veins (PVs) anatomy before atrial fibrillation (AF) ablation. However, it remains unclear whether pre-procedural imaging actually is associated with an improvement of efficiency, efficacy, and safety.

Purpose
Aim of the the study was to determine the impact of pre-procedural imaging using CT with 3-D reconstruction on procedural outcomes and radiological exposure in patients who undergo radiofrequency catheter ablation (RFA) to eliminate AF.

Methods
In this registry, 493 consecutive patients (age 62±8 years, 70% male) with paroxysmal (316) or persistent (177) AF who underwent RFA were included. A CT scan was obtained in 324 (66%) patients (CT Group) prior to RFA, while 169 (34%) didn't have any pre-procedural imaging (No-CT Group). Antral PVs isolation was performed in all patients along using an open-irrigation-tip catheter with a 3-D electroanatomical navigation system. Additional ablation applications were targeted if required. Procedural outcome, including radiological exposure, and clinical outcomes were compared among patients who underwent RFA with (CT-Group) and without (No CT-Group) pre-procedural imaging.

Results
Acute PV isolation was obtained in all patients. Additional ablation targets were targeted along the CTI (71/324 [22%] vs. 40/169 [24%], P=NS), the roof line (74/324 [23%] vs. 40/169 [24%], P=NS), the mitral isthmus (33/324 [10%] vs. 12/169 [7%], P=NS) and CFAEs (28/324 [8.6%] vs. 12/169 [7.1%], P=NS), without significant differences among groups. Complication rate were comparable between CT and No CT patients (4.3% vs 3%, P=0.7). In one Redo procedure of the No-CT Group, for the impossibility of identifying left PVs, a 3D LA fluoro-angiography was performed, which confirmed a left PVs occlusion. (Figure) No differences were observed about mean duration of the procedure (231±60 vs 233±58 min, P=0.7) and fluoroscopy time (13±10 vs 13±8 min, P=0.6) between groups. Cumulative radiation dose resulted significantly higher in the CT-Group (8.9±24 vs 4.8±15 mSV, P=0.02). Compared to paroxistical AF, persistent AF patients showed a comparable procedural-ED (6.6±26 vs 6±19, P=0.8) but with an higher CT-ED (1.7±2.9 vs 1.1±1.9, P=0.01).At 1 year, 227/324 (70%) and 119/169 (70%) of the patients who did and did not have pre-procedural imaging were free from AF (P = NS).
Figure 1

Conclusions
Pre-procedural CT does not improve safety and efficacy of AF ablation, increasing significantly the cumulative radiological exposure. Considering that patients candidate to AF ablation are often young, the cumulative radiation dose per life span and radiation dose reduction strategies should remain a matter of concern for doctors.

Acknowledgement/Funding
None