Tissue Oedema Following Pulsed Field Ablation Recognized during a Concomitant Left Atrial Appendage Closure Procedure. A Case Report

Background Combined procedure with pulmonary vein isolation (PVI) using thermal energy followed by left atrial appendage closure (LAAC) has been used in select patient populations with positive results. Pulsed field ablation (PFA) is a novel non-thermal ablation modality that ablates cardiac tissue by irreversible electroporation. The effect of PFA on cardiac tissue and its interaction with a LAAC device in a single procedure has not been studied. Purpose To evaluate using transesophageal echo (TEE) imaging the acute tissue response following ablation by PFA compared to radiofrequency ablation (RFA) and its interaction with the WATCHMAN FLX Pro LAAC device when used in a combined procedure in a healthy canine model. Methods Nine mongrel canines underwent PVI using either circumferential PFA (FARAPULSE) energy application (n=6) or RFA energy (n=3). TEE imaging was obtained at the time of the procedure before and immediately after ablation energy application. The general appearance and echogenicity of the left lateral ridge was assessed and the os of the left atrial appendage (LAA) was measured in the four standard TEE views (0, 45, 90, and 135 degrees). Decisions about device sizing were made accordingly. PVI was evaluated by entry and exit block in all veins except the right inferior pulmonary vein (RIPV), which was not ablated. Following ablation, the LAAC device was implanted using TEE and fluoroscopic guidance in all animals and the percentage of compression measured. PASS criteria were assessed before the release of each device. All animals received dual antiplatelet therapy post implant. Results PVI was confirmed in all animals (except RIPV which was not targeted for ablation) using PFA and RFA. LAA dimensions (at device landing site) did not change substantially after RF ablation. With PFA, there was evidence of more diffuse edema and decrease in LAA diameter (Table). The LAAC device was implanted successfully after meeting PASS criteria in all animals within 30 minutes post ablation. The device size was decreased following PFA in two (2/6) animals, whereas there was no deviation from baseline measurements in device size for any of the RFA animals. Average LAAC device compression was higher for PFA versus RFA animals (Table). TEE post implant confirmed absence of any peri-device leaks in all animals. Conclusion Concomitant PVI using PFA (FARAPULSE) and LAAC (WATCHMAN FLX Pro) is feasible with 100% success and no residual acute peri-device leak. In the canine model, PFA is associated with more diffuse edema compared to RFA, which might affect device sizing. Long term consequences of this acute edema need to be evaluated in serial imaging and future larger clinical trials.Table

The PROTECT AF and PREVAIL trials demonstrated that the WATCHMAN left atrial appendage (LAA) closure device is a reasonable alternative to warfarin therapy for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF) in the USA and Europe. We conducted the SALUTE trial to confirm the safety and efficacy of the LAA closure therapy for patients with NVAF in Japan. A total of 54 subjects (including 12 Roll-in) with NVAF who had a CHA2DS2-VASc score ≥2 were enrolled. All subjects were successfully implanted with the LAA closure device. No serious adverse events related to the primary procedure-safety endpoint occurred. The 2nd co-primary endpoint was a composite of all stroke, systemic embolism and cardiovascular/unexplained death. One ischemic stroke (1/42) occurred during the 6-month follow-up. The effective LAA closure rate defined as the 3rd co-primary endpoint was 100% (42/42) at both 45-day and 6-month follow-up. The procedural safety and 6-month results from the SALUTE trial demonstrated that the LAA closure device was safe and effective, similar to the results of large-scale randomized clinical trials, and provides a novel perspective of LAA closure for Japanese patients with NVAF in need of an alternative to long-term oral-anticoagulation. (Trial Registration: clinicaltrials.gov Identifier NCT 03033134).

B-PO02-074 LEFT ATRIAL APPENDAGE CLOSURE IMPACT ON ATRIAL FIBRILLATION RECURRENCE-RATE IN PATIENTS UNDERGOING PULMONARY VEIN ISOLATION

Introduction: Trials have shown that WATCHMAN left atrial appendage closure (LAAC) for stroke is noninferior to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation (AF). Since the approval of WATCHMAN, real world clinical outcome of LAAC is still limited. We performed a state wide analysis to evaluate clinical outcomes for AF patients undergo LAAC. Methods: Using the Healthcare Cost and Utilization Project (HCUP) State Inpatient Database, we included New York state adult patients, who had AF diagnosis with and without LAAC procedure from 2011 to 2017. Patients who had acute ischemic stroke (AIS) or history of AIS prior or during index admission were excluded. AF, AIS and other diagnosis were identified based on standard ICD-9 CM and ICD-10 CM codes. We compared rates of AIS, intracranial hemorrhage (ICH) and death between patients with and without LAAC. We also constructed a Cox regression model to determine hazard ratios (HR) of LAAC associated with each outcome. Results: Of the 627,972 patients with AF admitted, the mean age was 75.8 and 33.1% were female, and 773 (0.1%) underwent LAAC. AIS readmission occurred in 0.030% of AF patients without LAAC while it occurred in 0.012% of patients underwent LAAC. In the Cox regression model, LAAC had similar AIS readmission (HR 0.84, 95% CI 0.44-1.62, P = 0.602) and ICH readmission (HR 1.688, 95% CI 0.63-4.50, P = 0.296), but LAAC was associated with less death (HR 0.295, 95% CI 0.20-0.43, P < 0.001). These outcomes remained the same despite adjustment with common risk factors and insurance type, or adjustment with CHADS 2 VASC 2 scores. In sensitivity analysis, after restricting to patients that had ICH prior to index admission, LAAC again had similar AIS readmission (HR 1.884, 95% CI 0.26-13.46, P = 0.528) compared to non-LAAC group but still marginally associated with less death (HR 0.289, 95% CI 0.07-1.16, P = 0.080). Conclusion: In New York state, AF patients underwent LAAC procedural are less likely to have death during follow up despite adjustment of common risk factors or CHADS 2 VASC 2 score, while AIS and ICH readmission appears to be similar. However, given potential underlying confounding by treatment indication, these findings need confirmation by ongoing randomized control trials.

SummaryBackground:Stroke is a major complication of nonvalvular atrial fibrillation (AF). Despite its proven efficacy in stroke prevention, oral anticoagulation (OAC) is associated to a significant increase in bleeding complications. New techniques such as percutaneous left atrial appendage (LAA) closure were developed. Aim: To evaluate immediate, mid- and long-term outcomes after percutaneous LAA closure in Tunisian patients presenting with nonvalvular AF. Methods and Results:Nineteen patients with nonvalvular AF were prospectively enrolled for percutaneous LAA closure between February 2013 and June 2014. The Watchman device was used in all LAA closure procedures. Clinical and echocardiographic follow-up were carried-out at 1, 6, 12 months and six years in all patients. Mean age was 68.4 ± 7.5 years. Thirteen patients were female, 16 had hypertension, 12 had diabetes mellitus and seven had a history of stroke or transient ischemic attack (TIA). Average CHA2DS2VASc (Congestive Heart Failure/Left Ventricular Dysfunction, Hypertension, Age≥75, Diabetes mellitus, Stroke/Transient Ischemic Attack/Thromboembolic event, Vascular disease,Age≥65, Sex category) score was 4.2 ± 1.5 and HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding tendency, Labile INR, Age≥65, Drugs) score was 3.5 ± 1. Ten patients had a history of severe bleeding. Procedural success was achieved in all patients. Pericardial effusion with tamponade was reported in one case. No post-procedural death was reported. Regular follow-up at 1, 6 and12 months then every year up to 6 years reported no stroke, no thromboembolic event, no Watchman device thrombosis and three cases of death caused by a respiratory problem and cancers. ConclusionAccording to this study, LAA closure with Watchman device was safe and effective in preventing stroke in patients with nonvalvular AF and contra indication to OAC.

Background There are paucity of "real world" data on the actual impact of percutaneous left atrial appendage closure (LAAC) in the management of anticoagulated patients with atrial fibrillation (AF) and cancer after a severe bleeding (SB) event. Purpose Our main objective was to investigate the frequency, associated factors and impact on events of a LAAC strategy in anticoagulated AF patients with cancer surviving a SB versus those medically managed in Andalusia (South of Spain). Methods The PERSEO registry (Prevention of embolic events after a severe hemorrhage in anticoagulated patients with atrial fibrillation) was an observational, retrospective, multicentre study that included all consecutive patients discharged alive from January 1st, 2021 to December 31st, 2022, after an intracranial haemorrhage or severe gastrointestinal bleeding, who were previously anticoagulated for AF, in all public Andalusian hospitals with LAAC program, and who could be eligible either for LAAC or direct anticoagulant treatment. This analysis focuses in patients with a diagnosis of cancer in the 5 previous years. The frequency of a percutaneous LAAC strategy in the follow-up was registered, the differential features with those patients medically managed and the impact of this strategy on events in follow-up was investigated. Results Among a reference population of 7119044 inhabitants in 15 hospitals, 1403 patients were included in the study, and 224 had a cancer diagnosis in the 5 previous years and conform this study sample. Median age was 82 years [p25-75, 76-86 years] with 65.6% male patients. A LAAC procedure was performed in 15 patients (6.7%) at a median time of 9 [4-13] months after discharge. LAAC closure was independently associated with younger age, heart failure or left ventricular dysfunction, leukaemia and previous bleeding events (Table). After the procedure, the 15 patients treated with the LAAC strategy had a numerically better overall survival (81% versus 55%, p=0.260), survival free from embolic events (73% versus 54%, p=0.497), any bleeding (60% versus 43%, p=0.325) and any embolic or bleeding event (52% versus 38%, p=0.465) at 18 months, although all comparisons were non-significant (figure, panels A, B, C and D, respectively). Conclusions In anticoagulated patients with AF and cancer who survived a SB in all public hospitals with LAAC program in a large European region in 2021-2022, and who were also eligible for anticoagulation with DOAC, only 6.7% were managed with a LAAC strategy. Several baseline features were independently associated with this approach. Although we observed numerically fewer events in patients treated with LAAC, the statistical power was insufficient for conclusive results in this point.Table Figure

IntroductionThe aim of this study was to compare the feasibility, safety, and acute efficacy of pulmonary vein isolation (PVI) and left atrial roof ablation (LARA) using two pulsed field ablation (PFA) catheters – a pentaspline catheter and a circular PFA catheter – in patients with symptomatic atrial fibrillation (AF).MethodsWe enrolled consecutive AF patients who underwent either PVI alone or PVI combined with LARA using the pentaspline catheter (Farapulse™) or the circular array PFA catheter (PulseSelect™ PFA System) between November 2023 and September 2024. LARA was performed only in patients with persistent AF and left atrial enlargement (LA > 20 cm²). Patients with concomitant typical atrial flutter also underwent cavo-tricuspid isthmus (CTI) ablation.ResultsA total of 175 AF patients were included and divided into two groups: group 1 (N = 96) treated with the pentaspline PFA catheter and group 2 (N = 79) treated with the circular PFA catheter.Acute PVI was achieved in 100% of pulmonary veins in both groups. The total number of PFA applications for pulmonary veins (PVs) in group 1 was slightly higher than in group 2 (35 ± 3 vs. 34 ± 3, p < 0.01). In group 1, 29 patients (30.2%) received additional LARA, and 25 patients (31.6%) underwent LARA in group 2 (p = 0.97). LARA was performed with more PFA applications in group 1 than in group 2 (10.8 ± 5.5 vs. 8.5 ± 3.6, p < 0.01). In group 1, three patients received CTI ablation compared to five patients in group 2 (p = 0.47). CTI ablation was achieved with more PFA applications in group 1 (15 ± 6) than in group 2 (6 ± 4, p < 0.01). Conduction block across the left atrial roof and CTI was confirmed in all patients.Procedural times were longer in group 2, including total skin-to-skin time (61.6 ± 16.1 min vs. 67 ± 13.8 min, p < 0.01) and PFA catheter time in the left atrium (41.9 ± 14.0 min vs. 44.6 ± 10.6 min, p < 0.01). However, fluoroscopy time was shorter in group 2 (13.9 ± 5.7 min vs. 13.4 ± 4.7 min, p < 0.01).No significant differences in complication rates were observed between the groups (p = 0.69). Four procedural complications occurred in the pentaspline catheter group (two vascular access complications, one tamponade, and one transient ST elevation), and two vascular complications were noted in group 2.ConclusionThis study demonstrates comparable effectiveness between the two PFA systems for PVI and LARA. Although more PFA applications were performed by pentaspline catheter, the overall procedural time was shorter, while the circular catheter was associated with reduced fluoroscopy time. Both systems showed a similar safety profile. Further studies are needed to evaluate the long-term clinical outcomes of these PFA technologies.

Background There are no "real world" data on the actual impact of percutaneous left atrial appendage closure (LAAC) programs in the management of embolic event prevention after a severe bleeding (SB) in anticoagulated patients with atrial fibrillation (AF). Purpose Our main objective was to investigate the frequency of LAAC in anticoagulated AF patients surviving a SB event and to describe the differential features of these patients versus those medically managed in Andalusia (South of Spain). Methods All consecutive patients discharged alive from January 1st, 2021 to December 31st, 2022, after an intracranial or gastrointestinal severe haemorrhage, who were previously anticoagulated for AF, in all public Andalusian hospitals with LAAC program, and who could be eligible either for LAAC or direct anticoagulant treatment were included in a retrospective, multicentre study. The frequency of a percutaneous LAAC strategy in the follow-up was registered. A comparative analysis of baseline features between those patients treated with LAAC and those medically managed was performed. Results Among a reference population of 7119044 inhabitants in 15 hospitals, 1403 patients were included in the study. Median age was 81 years [p25-75, 76-87 years] with 51.6% male patients. A LAAC procedure was performed in 114 patients (8.13%) at a median time of 5 [2-10] months after discharge. After adjusting for confounding variables in a logistic regression model, LAAC closure was independently associated with intracranial hemorrhage (ICH), previous bleeding events, at least moderate valvular disease, leukemia and aspirin use at admission; and was more infrequently performed in patients aged &amp;gt;80 years, with dementia, uncontrolled blood pressure, vitamin K antagonist use at admission and interventional treatment of the bleeding event (Table). Variables with univariate association with LAAC (p&amp;lt;0.10) but excluded in backward stepwise regression after showing no significant independent association were hypercholesterolemia (rate of LAAC 9.5% vs 6.5% in non-hypercholesterolemia, p=0.04), diabetes mellitus (9.6% vs 7.2%, p=0.096), ischemic heart disease (11.9% vs 7.4%, p=0.02), heart failure or left ventricular dysfunction (9.9% vs 7.1%, p=0.06), connective tissue disease (0.0% vs 8.3%, p=0.09), chronic obstructive pulmonary disease (5.3% vs 8.7%, p=0.08), peptic ulcer disease (11.9% vs 7.7%, p=0.09), baseline heart rate (70[64-80] vs 75[66-87] bpm, p=0.003) and platelet count (201[158-244] vs 212[166-269]/nL, p=0.08). Conclusions In anticoagulated patients with AF who survived a SB event in all public hospitals with LAAC program in a large European region in 2021-2022, and who were also eligible for anticoagulation with DOAC, only 8.13% were managed with a LAAC strategy. Several baseline features were independently associated with higher or lower frequency of this approach.Table

Objective Percutaneous left atrial appendage closure(LAAC)has been developed for stroke prevention for high-risk atrial fibrillation(AF)patients in recent years.For AF patients complicated with coronary artery disease(CAD), trpl anti-coagulation was related with high bleeding risk, thus we hypothesized that LAAC might yield benefit for its lower hemorrhagic risk compared to oral anticoagulants.This is a retrospective, single-center study aimed to investigate the safety and efficacy of LAAC in high-risk AF patients with coronary artery disease. Methods From May 2014 to November 2015, 36 AF patients with CAD underwent percutaneous LAAC operations at Wuhan Asia Heart Hospital.All CADs were confirmed by coronary angiography or coronary artery CTA.The clinical feature, LAA morphology, LAAC procedure and follow-up data of these patients were reviewed. Results Thirty-six patients were included, who were all high-risk NVAF patients complicated with stable CAD.The average CHA2DS2-VASc score was 2.94±1.43, and the average HAS-BLED score was 2.00 ±0.79.Successful left atrial appendage closures were achieved in all 36 patients.There was one case of ischemic stroke during peri-operative period, which responded well to drug therapy.During the 12 months of follow-up, there was no major bleeding or ischemic stroke/system embolism.33 patients completed TEE 45 days post-operative, which revealed 7 patients with residual flows of (2.67±1.50) mm, and 2 device-related thrombi, who continued anti-coagulatants.34 patients discontinued warfarin/dabigatran at 45 days after LAAC operations. Conclusion This study showed that percutaneous LAA closure could be performed as an effective and safe alternative for stroke prevention in high-risk NVAF patients complicated with stable CAD. Key words: Atrial fibrillation; Left atrial appendage closure; Coronary artery disease.

Left atrial appendage edema and spontaneous echo contrast following pulsed field ablation for pulmonary vein isolation: A case report.

It remains unknown if the left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischaemic cerebrovascular accidents. Consecutive 310 patients who underwent LVAD surgery with HeartMate II or 3 between January 2012 and November 2021 were included in this study. The cohort was divided into 2 groups: patients with LAAC (group A) and without LAAC (group B). We compared the clinical outcomes including the incidence of cerebrovascular accident between 2 groups. Ninety-eight patients were included in group A, and 212 patients in group B. There were no significant differences between 2 groups in age, preoperative CHADS2 score and history of atrial fibrillation. In-hospital mortality did not differ significantly between the 2 groups (group A: 7.1%, group B: 12.3%, P = 0.16). Thirty-seven patients (11.9%) experienced ischaemic cerebrovascular accident (5 patients in group A and 32 patients in group B). The cumulative incidence from ischaemic cerebrovascular accidents in group A (5.3% at 12 months and 5.3% at 36 months) was significantly lower than that in group B (8.2% at 12 months and 16.8% at 36 months; P = 0.017). In a multivariable competing risk analysis, LAAC was associated with reducing ischaemic cerebrovascular accidents (hazard ratio 0.38, 95% confidence interval 0.15-0.97, P = 0.043). Concomitant LAAC in LVAD surgery can reduce ischaemic cerebrovascular accidents without increasing perioperative mortality and complications.

Background There are limited effective treatment options for persistent atrial fibrillation (AF) patients, with pulmonary veins (PV) isolation alone being considered suboptimal for many patients. Hybrid convergent ablation has been shown to improve clinical outcomes when compared to an endocardial-only radiofrequency (RF) strategy. Pulsed field ablation (PFA) has recently gained growing interest for its efficacy and safety profile in PV and posterior wall (PW) ablation. Objectives To compare clinical outcomes of hybrid convergent RF ablation versus endocardial PFA for PV and PW isolation in patients with persistent AF. Methods From July 2022, 86 persistent AF consecutive patients, receiving endocardial PFA of PV and PW (PFA group, N = 44) or receiving hybrid convergent RF ablation (Hybrid group, N = 42) at our institution were enrolled. Recurrence was defined as any atrial tachyarrhythmia following the 3-month blanking period. Results No differences were found between PFA and Hybrid groups regarding age (PFA 66.0±7.4 years vs Hybrid 63.9±10.6 years; p=0.193) and left atrial volume index (PFA 45.5 [36.7-57.2] ml/m² vs Hybrid 45.0 [39.2-59.7] ml/m²; p=0.920). Differences regarding left ventricular ejection fraction were borderline significant among groups (PFA 55.0 [49.5-62.0]% vs Hybrid 60.5 [52.3-65.0]%; p=0.048), both showing an overall normal LV function. There were no significant differences regarding AF duration (PFA 38.0 months [IQR: 19.2 to 99.0 months] vs Hybrid 70.0 months [IQR: 46.0 to 118.0 months]; p = 0.063). Redo ablation patients’ rate was higher in the hybrid group (PFA n=16, 36.4% vs Hybrid n=28, 66.6%; p&amp;lt;0.001). Procedure duration was Ionger in the hybrid group (179.9±60.1 minutes) compared to PFA endocardial ablation (PFA 106.2±30.7 minute; p&amp;lt;0.01). After a median follow-up of 233.0 [179.0–331.8] days, there was no difference in atrial tachyarrhythmias recurrence rate (PFA n=11, 25.0% vs Hybrid n=10, 23.8%; p=0.897); no difference in the antiarrhythmic drug use rate was found (PFA n=24, 54.5% vs Hybrid n=19, 45.2%; p=0.388). Conclusions PFA of PV and PW, compared with the hybrid convergent ablation strategy, is an endocardial-only, less invasive, and faster procedure. 6-month rhythm outcomes were similar in both groups.

Wide-area antral pulmonary vein and posterior wall isolation by way of segmental nonocclusive applications using a novel radiofrequency ablation balloon

The newly introduced nonthermal pulsed field ablation (PFA) is a promising technology to achieve fast pulmonary vein isolation (PVI) with high acute success rates and good safety features. However, previous studies have shown that very high power short duration ablation (VHPSD) is also highly effective and fast to achieve PVI with potentially less arrhythmia recurrence compared to conventional radiofrequency ablation. Data comparing PFA to VHPSD-PVI is lacking. This study compared procedural and outcome data for PFA-PVI to VHPSD-PVI in patients with paroxysmal or persistent atrial fibrillation (PAF/persAF). Consecutive patients undergoing de novo PVI (PFA or VHPSD) were included in this analysis. For PFA-PVI a pentaspline 20 electrode catheter was used. For VHPSD-PVI an enhanced irrigated catheter with a power setting of 70 W/7 s (70 W/5 s at posterior wall) was employed in conjunction with electro-anatomical mapping. All procedures were performed in deep analgo-sedation. A total of n = 114 patients (n = 57[50%] PFA, n = 17[30%] PAF; n = 40[70%] persAF) were included in this analysis. PVI was successful in all patients. The PFA group revealed a significantly shorter procedure duration (65 ± 17 min vs. 95 ± 23 min, p < 0.01) but longer fluoroscopy time (PFA 15 ± 5 min and VHPSD 12 ± 3 min; p < 0.001). At follow-up after median 125 days (interquartile range: 109-162) n = 46 PFA (80.7%) and n = 44 VHPSD pts (77.2%) were free from atrial arrhythmia after a single procedure (p = 0.819). Two tamponades occurred in the PFA while in VHPSD two pts suffered groin bleedings. One clinically nonsignificant PV stenosis occurred in the VHPSD group. Pulsed-field ablation and VHPSD-PVI seem to be highly effective and safe to achieve PVI in the setting of PAF and persAF with comparable arrhythmia-free survival. However, procedure duration for PFA PVI is significantly shorter and therefore may be of potential benefit. Compared to PFA VHPSD-PVI might ensure information on left atrial substrate allowing to target concomitant secondary tachycardias.

Funding AcknowledgementsType of funding sources: None.BackgroundComplete electrical pulmonary vein isolation (PVI) by thermal energy sources is a well-established ablation strategy of atrial fibrillation (AF). Recently, a non-thermal ablation approach by means of irreversible cellular electroporation has been made available for clinical use.PurposeWe report the preliminary experience of a new pulsed-field ablation (PFA) system in the context of AF ablation in a multicenter Italian setting.MethodsAll consecutive patients (pts) undergoing AF ablation with PFA at 7 Italian centres were included. Protocol-directed PVI was delivered using 2000 V with eight applications per vein, that is, four applications each in the basket and flower poses. Applications were delivered in pairs at any given catheter position, rotating by ≈30–40° after the first two applications in each configuration. Additional lesions were performed at the operator’s discretion. The ablation endpoint was PVI as assessed by entrance and exit block. Data are reported as median [IQ range].ResultsWith a median of 32[25-38] pts treated per center, a total of 205 cases were included (n=150 73.2%, paroxysmal AF, n=55, 26.9% persistent AF). Of them 187 (91.2%) were de novo cases, whereas 18 (8.8%) were redo cases. A mapping system was used in 55 (21.5%) procedures and an intracardiac echocardiography in 65 (31.7%) cases. The number of PFA applications to reach PVI was 32[32-36]. Procedural parameters were: fluoroscopy time = 16[12-22] min, skin-to-skin time = 60[55-85] min, support time (preparation plus skin-to-skin) =75[64-95] min, lab occupancy time was 97[75-120] min and PFA LA dwell time was 23[20-28] min. The first pass isolation (FPI) rate per vein was 99.6% resulting from 202 patients (98.5%) with FPI. At the end of the procedure, PVI was achieved in all pts (100%) using only PFA. Additional PFA delivery outside PVs was performed in 19% (n=39) of the cases, mostly at the posterior wall area only (n=34, 87%), requiring 16[12-24] PFA deliveries. All the additional lesion sets were validated through differential pacing and/or 3D mapping. The learning curve was extremely fast. After only 5 cases time to PVI and total support time have significantly improved, whereas we did not notice any additional improvement after 10 or 20 cases (LA dwell time: 27[22-32] min during the first 5 cases vs 23[19-27] min after the first 5 cases, p=0.0172; support time: 100[65-120] min vs 75[65-90] min, p=0.0181, respectively). In 13 (6.3%) cases a transient bradycardia or asystole occurred after the first PFA application requiring temporary high-output pacing. No major procedure-related adverse events were reported.ConclusionIn this first multicentric experience, the novel PFA system proved to be safe and effective in both paroxysmal and persistent AF patients. The learning curve seems to be very fast according with procedural parameters.