232Accessory pathway ablation in adults: estimated additional cancer risk depending on the mapping and ablation strategy

Introduction Catheter ablation is the treatment of choice for accessory pathways (AP) in high risk patients and it´s usually performed under fluoroscopy guidance (reported X-Ray time:16 -38min).Radiation exposure is associated with an increased incidence of dermatitis,gene defects, cataract and malignancy.3-D mapping systems(EAMS) can reduce fluoroscopy exposure. Purpose To evaluate the additional cancer risk throughout life in 2 homogeneous adult populations of high-risk APs treated either with conventional fluoroscopically guided ablation (CFA) or with an EAM- and echocardiography(TEE or ICE)guided minimally fluoroscopic ablation approach (MFA).Methods: 2 Center study, 60 consecutive pts enrolled; 31pts underwent CFA at IRCCS Policlinico san Matteo (Pavia) and 29 pts underwent EAM guided MFA at Klinikum Fuerth between 01/2016 and 09/2019.The age and gender-adjusted cancer risk was calculated following Monte Carlo code,according to Biological Effects of Ionizing Radiation (BEIR VII) empirical risk models. Results The estimated additional cancer risk throughout life gained with a single ablation procedure was significatively different between groups:0.18% in CFA compared to 0.001% in MFA group(P < 0.001).The maximum estimated additional cancer risk for a patient undergoing CFA was 1%.10 out of 29 MFA procedures(35%)were successfully performed with zero fluoroscopy. Conclusions:Our small study demonstrates that an echocardiography/EAM guided approach allows safe AP ablation adding a significantly reduced estimated cancer risk compared to CFA in young adults,a population sensitive to X-ray exposure regarding the stochastic risk of developing malignancies.This finding strongly supports the recommendation for a routine use of EAMS in AP ablations,including appropriate reimbursement. Results Conventional fluoroscopic approach Minimal fluoroscopic approach p Patient (N) 31 29 n.s. Age (Y) 43.7 ± 14 44.7 ± 17 n.s. Right AP 10 6 n.s. Left Ap 21 23 n.s. Transeptal Access 20 22 n.s. Complications 1 (3%) 0 n.s. DAP (µGy*m2) 15252+/-11132 56.8+/-135.6 0.000 Effective Dose (mSv) 30.35+/-27.7 0.09+/-0.28 0.000. Additional Cancer Risk 0.18% 0.001% >0.001 N, number; Y, years; AP, Accessory Pathway.