Impact of 3-dimensional electroanatomic mapping systems on fluoroscopy reduction in catheter ablation of supraventricular tachycardia - then and now

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an effective first-line treatment for symptomatic and recurrent supraventricular tachycardia (SVT). The advent of 3D electroanatomic mapping (EAM) has led to a reduction in fluoroscopy use and consequently lower radiation exposure for patients and staff during SVT ablation. Purpose The aims of this study are to demonstrate if the use of EAM during SVT ablation reduces fluoroscopy time (FT), and determine if further reductions in FT are observed longitudinally. We hypothesise that over time, with continued use and wider adoption of EAM, greater operator experience, and technological advancements in EAM, there will be further reductions in radiation exposure as estimated by FT. Methods All cases of atrioventricular nodal re-entry tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT), and/or atrial tachycardia (AT) ablation between May 2011 to May 2022 at a tertiary centre were prospectively recruited. FT between the groups with and without EAM were compared. Within the EAM subset, the trend of FT across the years was also analysed. Results Over this 11-year period, there were 1758 cases of SVT ablation (565 without EAM; 1193 with EAM). Between the two groups, there were no significant differences (p > 0.05) in age, sex, history of structural heart disease and/or ischaemic heart disease, stereotaxis use, and diagnosis (AVNRT, AVRT, AT). Cases using EAM were more likely to have >1 SVT ablated during the procedure (0.04) and require intracardiac echocardiography (ICE) (p < 0.001). The use of EAM was associated with mean reductions in FT and dose area product (DAP) by 19.6 minutes and 18 581 mGy*cm2 respectively (both p < 0.001). EAM was also associated with a longer procedure time (mean +8.8 minutes, p < 0.001). There was no difference in radiofrequency application time between the two groups (p = 0.143). After controlling for potential confounding factors including age, sex, use of stereotaxis, use of ICE, type and number of SVT, history of prior ablation, and structural heart disease and/or ischaemic heart disease, we found over time (2011-2022), further reduction in FT was observed, with a mean reduction of 0.9 minutes year on year (p < 0.001). EAM was gradually adopted through the years with the number of cases per year plateauing after 2017. Between 2011-2017, there was a significant reduction in FT (mean of -1.1 minute year on year, p = 0.020), which was not observed from 2017 onwards (p = 0.088). The greatest reduction in FT was observed after the first year of adoption, with a mean reduction of 6.9 minutes between 2012-2013. Conclusion This demonstrates that use of EAM in SVT ablation reduces FT and fluoroscopy DAP. There was no incremental benefit observed after 6 years of EAM adoption likely related to operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in select complex cases.