1249Acute efficacy and safety of pulmonary vein isolation for atrial fibrillation in patients alternatively assigned to high power short duration (70W, 8s) vs lesion index guided (35W) ablation

Abstract Background permanent trans-mural lesions not affecting surrounding anatomical structures is the goal of safe and effective wide antral pulmonary vein (PV) isolation in patients with paroxysmal and persistent atrial fibrillation (AF) undergoing catheter ablation (CA). Time, energy and contact force are parameters related to lesion goodness and incorporated in a complex formula (i.e. the lesion index, LSI™, Abbott). This parameter is emerging as the gold standard for PV isolation. Recently, the shallower but wider lesions created by high power short duration (HPSD) ablation has came to attention. Purpose to compare acute reconnection rate, procedural  parameters, and complication rates in patients with paroxysmal or persistent AF undergoing CA. Methods one-hundred patients with paroxysmal and 100 with persistent AF will be alternatively assigned to undergo PV isolation with the FlexAbility™ (HPSD group, 70W, 41°, 8 seconds) or the TactiCath™ (LSI-group: 35W, 41°, LSI: 5-5.5 posterior wall, up to ≥6 anywhere else) catheter. A 3-D mapping system (Ensite Precision™) and a steerable sheath (Agilis™, both Abbott) were always used. Adenosine (30mg) is given after PV isolation and ≥ 20 minutes waiting time. Posterior wall isolation was added in all, and patients with persistent AF were additionally treated with mitral and cavotricuspid isthmus ablation. Results: between June and October 2019, 71 patients (68 ± 10 years old, 32 (45%) female, 44 (60%) paroxysmal AF, AF duration 58 ± 81 months) were alternatively assigned to HPSD (36, 51%) or LSI-guided (35, 49%) ablation. No difference in clinical characteristics was found between groups. After 44 ± 18 and 30 ± 14min of procedural and RF time, all PVs were isolated, and all 17 (24%) reconnections treated with an additional 4 ± 3 and 3 ± 2min, respectively. In 8 ± 3 and 7 ± 3 min of procedural and RF time, the PW was successfully isolated in all. PV isolation (34 ± 12min vs. 56 ± 16min; P<.0001), RF (18 ± 5min vs. 41 ± 9min; P<.0001), and total procedural (138 ± 34min vs. 162 ± 34min; P=.0026) time were shorter in the HPSD group. X-Ray time and effective dose did not differ. A similar rate of acute reconnections (9, 25% vs. 8 23%) was found when HPSD and LSI were compared. A higher, although statistically not significant, number of steam pops was observed in the HPSD (14, 39%) vs. LSI (8, 23%) group, possibly related to the higher incidence of moderate pericardial effusion (>0.5mm, <20mm) found the day following the ablation (10, 28% vs. 2, 6%; P=.0238). No further complications related to CA were detected. Conclusions in patients with paroxysmal and persistent AF undergoing their first CA, HPSD ablation is faster than an LSI-guided approach. Acute efficacy (reconnection rate) is similar. Although a higher rate of haemodynamically non-relevant pericardial effusions were seen in the HPSD group, these were all treated medically and the general safety profile of this approach is excellent and comparable to LSI ablation.