P1909The impact of ECG synchronization during acquisition of left atrium computed tomography model on radiation dose and arrhythmia recurrence rate after catheter ablation of atrial fibrillation

Abstract

Background: A fusion of electroanatomical (EA) map with a 3D computed tomography (CT) model of left atrium (LA) is routinely used to acquire anatomical details before atrial fibrillation (AF) catheter ablation (CA). A widely-used gold standard for a CT procedure is not defined. Objective(s): To evaluate the impact of ECG-gating on radiation dose, image quality and ablation outcome. Method(s): 62 patients scheduled for AF ablation were randomized 1:1 for two types of LA CT. Group 1: CT with retrospective ECG gating. Group 2: helical CT without ECG gating. A visual 5-point scale was used for CT image quality assessment. CT Dose Index (CTDIvol) and Dose Length Product (DLP) were used to compare radiation exposure. CA was done by a CT-type-blinded operator. A fast EA map (FAM, CARTO3) and merge with LA model (Carto3-Merge) were used. Variance between EA map and CT model were evaluated. All patients were put off antiarrhythmic drugs. Four seven-days Holter-ECG monitorings were evaluated for an arrhythmia recurrence during 12 months after ablation. Result(s): We have found a significant difference between both groups in radiation dose - CTDI (89.55+/-5.99 vs. 19.19+/-4.33 mGy, p<0.0001), DLP (1438.87+/-147.75 vs. 328.21+/-73.83 mGy*cm, p<0.0001). There was no difference between the groups in visual data quality (1.77+/-0.88 vs. 2.0+/-0.63, p=0.102), average CT/FAM variance (2.42+/-0.72 vs. 2.43+/-0.46 mm, p=0.612), CA length (131.61+/-32.57 vs. 119.84+/-33.18 min, p=0.108), CA fluoroscopy time (4.48+/-2.19 vs. 3.89+/-1.83, p=0.251) and CA fluoroscopy length (4258.26+/-2964.94 vs. 4075.68+/-2845.85, p=0.741). There was no difference in body-mass-index (27.92+/-4.46 vs. 29.66+/-3.51, p=0.116). 12 months after ablation, 6/31 (80.65%) patients were free of AF in group 1 and 7/31 (77.42%) in group 2. Conclusion(s): ECG-gating of computed tomography of left atrium before atrial fibrillation catheter ablation burdens patients with four times higher radiation dose without improving quality of left atrium CT model, quality of fusion of CT and electroanatomical map or catheter ablation parameters and with no impact on arrhythmia recurrence rate after ablation.