Very (70W) vs. LSI guided (5-6) high power short duration ablation in patients with paroxysmal atrial fibrillation undergoing pulmonary vein vs. pulmonary vein and posterior wall isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background high power short duration (HPSD) ablation is at least as safe while reducing procedure time than radiofrequency (RF) ablation with lower power in pts undergoing pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF). Purpose: to compare safety and efficacy of 2 different: 1) RF energy set up (FlexAbility: 70W, 41°, 6-10s, 11ml/h vs. TactiCath: 50W, 41°, LSI 5-6, 17ml/h, both Abbott), and 2) ablation strategies (posterior wall isolation (PWI) in addition to PVI vs. PVI) in pts undergoing their first ablation for paroxysmal AF. Methods: since June 2020 pts are prospectively assigned to alternatively undergo their RF catheter ablation with the FlexAbility (v-HPSD) or the TactiCath (LSI-HPSD) catheters (aim 200 pts). In addition, pts were alternatively assigned to PVI + PWI vs. PVI. All procedures were done using a 3D-mapping system (Ensite Precision), the ablation catheter was stabilized with a long sheath (Agilis) and a continuous series of lesions (4mm) were plotted around the PV, at the roof and between the 2 inferior PVs. On the PW, RF lesions were limited to 6s and 5 LSI for the v-HPSD and LSI-HPSD groups. Endoscopy was performed shortly after ablation in all pts and thermal esophageal lesion (TEL) characterized with the Kansas classification. Results: since June 2020 56 pts [61 ± 13 years old, 17 (30%) female, CHA2DS2-Vasc 2.3 ± 1.5, 55 ± 77 left ventricular ejection fraction] underwent v-HPSD (#28) and LSI-HPSD (#28) ablation. In 2/14 (14%) and in 3/15 (20%) pts (v-HPSD and LSI-HPSD groups, respectively) initially assigned to undergo simple PVI, PWI was added due to PW dependent flutter or evidence of pro-arrhythmic slow conduction on the PW. A shorter RF time to achieve PVI (17 ± 3 vs. 25 ± 6 min; P<.0001) was found for the v-HPSD group, although acute reconnection were numerically higher (9 vs. 4) and procedural time did not differ (32 ± 8 vs. 35 ± 9 min). Whenever attempted, PWI (#16 for each v-HPSD and LSI-HPSD group) was always successful. When v-HPSD and LSI-HPSD group were compared, no differences were found in RF and procedure time both at the roof (2.3 ± 0.9 vs. 2.7 ± 1.1 min and 3 ± 1.4 vs. 3.4 ± 1 min, respectively) and between the 2 inferior PVs (2.6 ± 0.6 vs. 2.9 ± 0.7 min and 4.3 ± 1.9 vs. 3.8 ± 1.2 min, respectively). Total RF (19.7 ± 4.5 vs. 28.5 ± 6.6 min, P<.0001) was shorted in the v-HPSD, but X-Ray (1.4 ± 0.7 vs. 1.2 ± 0.8 min) and total procedural time (102 ± 17 vs. 110 ± 20 min) did not differ. Rate of TELs was not different and found in 18% (#5: 4 I, 1 IIA) and 14% (all IIA) pts assigned to v-HPSD and LSI-HPSD respectively. A numerically higher number of TELs (6 vs. 3) was seen when PWI was pursued, although this did not prolong total RF and procedure time. Conclusion: a shorter RF time is associated with v-HPSD vs. LSI-HPSD strategy, although procedural time did not differ. TELs are a relative rare finding, and only numerically higher when isolation of the PW is pursued in addition to PV isolation.