Pulmonary Vein Isolation In Patients Research Articles

Methods, efficacy and safety on routine clinical use of pulsed field ablation for pulmonary vein isolation in patients with atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (AF). It is also used as off-label therapy for persistent AF. Only a few small clinical studies have been published on the mid- and long-term outcome. We present data on methods, efficacy and safety on routine clinical use of pulsed field ablation for pulmonary vein isolation in patients with atrial fibrillation. Methods In patients with AF, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps using a pentaspline diagnostic catheter were performed. Procedural parameters, acute success and in-hospital safety were assessed. Results A total of 5 operators treated 304 patients (mean age 67 years (range 32-85), female 42%, mean BMI 28 kg/m2 (range 20-42), mean CHA2DS2-VaSc score of 2 (range 0-7), first-time ablation 100%, paroxysmal/persistent/longstanding persistent AF 47/17/36%, respectively. Mean duration since first AF diagnosis was 79 months (range 0-332). Most procedures were performed under deep conscious sedation using propofol and midazolam, without intubation (99%). Pre- and post-ablation high-density maps were performed in 27% of cases. Mean procedure time was 75 min. (range 23–245). Mean left atrial dwell time of the PFA catheter was 25 min. (range 8-98). Fluoroscopy time and dose area product were 18 min. (range 6-50) and 5,74 Gy.cm2 (range 0,40-36,50), respectively. Pulmonary vein isolation (PVI) was successful in 100%. There were no phrenic nerve palsies or esophageal complications. Major complications (2,6%) were pericardial tamponade (2,0%) and stroke (0,7%); one of these strokes was lethal (0,3%). Minor complications (1,0%) were vascular access related (0,7%) and transient ischemic attack (TIA) (0,3%). Conclusions In a large, single center cohort of unselected patients, initial experience with de novo PFA for PVI in patients with AF seems to be fast and effective. There were no PFA-specific complications, but the frequency of catheter complications (tamponade, stroke) in this relatively old patient population with a relatively long history of AF demonstrates that there is still room for improvement. The number of complications improved significantly over the course of time, indicating that the learning curve could have negatively influenced the incidence of complications.

Pulsed-field- vs. cryo- vs. radiofrequency ablation: one-year recurrence rates after pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background A multipolar pulsed-field ablation (PFA) catheter has recently been introduced and showed favorable data in terms of safety and procedural efficiency of pulmonary vein isolation (PVI) for atrial fibrillation (AF). Long-term outcome data in comparison to other ablation modalities however is lacking. Purpose To compare procedural and one-year recurrence data of patients with paroxysmal AF (paroxAF) undergoing a first PVI using PFA, cryoballoon ablation (Cryo), or radiofrequency (RFA). Methods Consecutive patients with paroxAF undergoing a first PVI with PFA at our institution from May to December 2021 were included. For comparison, patients with paroxAF undergoing a first PVI with Cryo or RFA between May 2020 and March 2021 were included. A 3-D electro-anatomical mapping system was used in PFA and RFA, but not in Cryo. The following ablation protocols were used to achieve acute PVI: In the PFA group, the standard 32-applications lesion-set and supplementary applications at the discretion of the operator. In the Cryo group, a time-to-effect plus two minutes strategy and in the RFA group following to the CLOSE protocol. Patients were followed with 7d-Holter ECGs 3, 6, and 12 months after ablation. The primary endpoint was recurrence of any atrial arrhythmias following a blanking period of 3 months. Results A total of 202 patients were included (PFA: 32; Cryo: 82; RF: 88). Age, gender, CHA2DS2-VASc score, LVEF and LAVI did not differ among the groups (Table). Median procedure times were shortest with Cryo (76 [interquartile range 60-95] min) followed by PFA (94 [82-110] min) and RFA (157 [126-211] min, p < 0.01). Fluoroscopy dose was lowest with RFA (1.4 [0.6-2.5] Gycm2) followed by PFA (4.8 [3.5-7.9] Gycm2) and Cryo (5.3 [2.8-10.2] Gycm2, p < 0.01). Median follow-up time in patients without recurrence was 12 [10-12] months for the PFA group, 12 [12-13] months for the Cryo group and 13 [12-13] months for the RFA group. There was a trend towards fewer recurrences of atrial arrhythmias with PFA compared to Cryo and RFA (PFA 7%, Cryo: 25%, RFA: 20%, p = 0.13, Figure). Conclusion Recurrences of atrial arrhythmias 12 months after PFA PVI for paroxAF may be lower compared to Cryo and RFA. Larger prospective randomized studies are needed to confirm this initial experience.

Novel pulsed-field ablation technology for pulmonary vein isolation in patients with atrial fibrillation: preliminary experience from a large multicenter clinical practice

Abstract Funding Acknowledgements Type of funding sources: None. Background Complete 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. Purpose We report the preliminary experience of a new pulsed-field ablation (PFA) system in the context of AF ablation in a multicenter Italian setting. Methods All 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]. Results With 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. Conclusion In 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.

Robotic magnetic navigation guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation, when compared to conventional techniques

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation (CA) is an important treatment option for patients with atrial fibrillation (AF). Pulmonary vein isolation (PVI) is a pivotal part of any AF ablative therapy. Currently, there are multiple techniques available to realize PVI, including: manual guided cryoballoon (MAN-CB), manual guided radiofrequency (MAN-RF) and Remote Magnetic Navigation guided RF ablation (RMN-RF). However, there is lack of large prospective trials comparing contemporary RMN-RF with the conventional CA techniques. Purpose This study prospectively analyzed and compared three catheter ablation techniques in patients with paroxysmal AF. Methods This multicenter, prospective study included patients with paroxysmal AF who underwent their first CA procedure with one of the mentioned ablation techniques. Procedural parameters (including procedural efficiency), complication rates and freedom of AF during 12-month follow-up were compared between three study groups defined by the utilized ablation technique. Results A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78±21 min) compared to MAN-RF (115±41 min) and compared to RMN-RF (129±32 min) (P<0.001), whereas it was comparable between the two RF groups. A 3% complication rate was observed which was comparable between all groups. At 12-month follow-up, we observed AF recurrence in 40 patients (19%). AF recurrence was significantly lower in the RMN-RF group (MAN-CB 19 (24%) AF recurrences, MAN-RF 16 (23%), RMN-RF 5 (8%), P=0.045; multivariate HR of RMN-RF on AF recurrence 0.32, 95%-CI 0,12–0.87, P=0.026; with MAN-CB + MAN-RF as the reference group). Conclusion RMN guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time efficient ablation technique, whereas RMN has comparable efficiency with manual RF ablation.

Pulsed-field- vs. cryo- vs. radiofrequency ablation: one-year recurrence rates after pulmonary vein isolation in patients with persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background A multipolar pulsed-field ablation (PFA) catheter has recently been introduced and showed favorable data in terms of safety and procedural efficiency of pulmonary vein isolation (PVI) for atrial fibrillation (AF). Long-term outcome data in comparison to other ablation modalities however is lacking. Purpose To compare procedural and one-year recurrence data of patients with persistent AF (persAF) undergoing a first PVI using PFA, cryoballoon ablation (Cryo), or radiofrequency (RFA). Methods Consecutive patients with persAF undergoing a first PVI with PFA at our institution from May to December 2021 were included. For comparison, patients with persAF undergoing a first PVI with Cryo or RFA between May 2020 and March 2021 were included. A 3-D electro-anatomical mapping system was used in PFA and RFA, but not in Cryo. The following ablation protocols were used to achieve acute PVI: In the PFA group, the standard 32-applications lesion-set and supplementary applications at the discretion of the operator. In the Cryo group, a time-to-effect plus two minutes strategy and in the RFA group following to the CLOSE protocol. Patients were followed with 7d-Holter ECGs 3, 6, and 12 months after ablation. The primary endpoint was recurrence of any atrial arrhythmia following a blanking period of 3 months. Results A total of 177 patients were included (PFA: 65; Cryo: 63; RF: 49). Age, gender, CHA2DS2-VASc score, LVEF and LAVI did not differ among the groups (Table). Median procedure time was different among the groups (PFA: 109 [interquartile range 88-130] min, Cryo: 81 [62-96] min, RF: 177 [153-200] min, p < 0.01). Fluoroscopy dose was different among groups: RF (1.9 [0.7-4.9] Gycm2), PFA (8.3 [4.3-19.0] Gycm2), and Cryo (9.5 [4.8-19.1] Gycm2, p<0.01). Median follow-up time in patients without recurrence was 13 [11-13] months for the PFA group, 13 [12-13] months for the Cryo group and 12 [11-13] months for RFA group. Recurrence of atrial arrhythmias in the KM-analysis after 12 months was not different in all three groups (PFA 44%, Cryo: 33%, RFA: 51%, Figure). Conclusion In patients with persAF, recurrence of atrial arrhythmias 12 months after PFA-PVI only is high, regardless of ablation modality. Assessment of strategies including ablation of extra-PV targets in some patients with persAF is needed.

Effect of early pulmonary vein isolation in patients with heart failure and reduced ejection fraction

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) and heart failure (HF) often coexist leading to worse outcomes compared to AF or HF alone. According to the current guidelines, PVI as first-line therapy should be considered, however, the optimal timing of the procedure is still unknown. Purpose We aimed to investigate the effect of early PVI on all-cause mortality and AF recurrence in patients with HFrEF. Methods We analyzed the data of 162 patients with symptomatic paroxysmal or persistent AF and heart failure with LVEF < 50% who underwent pulmonary vein isolation between 2010 and 2022. The patients’ medical history, laboratory results, echocardiographic and periprocedural parameters were collected in a structured registry. Early PVI was defined as catheter ablation performed within 12 months of AF diagnosis. The median follow-up was 59.7 months, the minimum follow-up was 12 months. Our primary endpoints were AF recurrence after a 3 months blanking period and all-cause mortality at any time during follow-up. Results Among the 162 patients, 77 experienced AF recurrence and 39 patients died during the follow-up period. The median age was 63.2 years. The median LVEF was 40% for early PVI and 37% for deferred PVI. Out of the 63 patients who underwent early PVI, 33 (52%) were taking amiodarone. Patients who underwent early PVI had longer freedom from recurrence (median 833 days until recurrence for early PVI, median 696 days for deferred PVI). Early PVI was a predictor of AF recurrence (HR: 0.58 [0.32-0.94], p=0.029).Early ablation was not associated with mortality benefit. However, among those who experienced AF recurrence, repeated ablation was associated with better survival during univariate Cox regression (p=0.01). Furthermore, in multivariate model, reablation was shown to be protective of mortality (HR: 0.312 [0.113-0.865], p=0.025) in the whole cohort. Conclusions Our study shows that early rhythm control therapy with catheter ablation is more successful compared to deferred PVI in patients with AF and HFrEF. A redo-PVI was associated with better survival, thus a repeat ablation should be considered in case of arrhythmia recurrence in patients with AF and HF to reduce mortality.

The impact of posterior wall ablation in conjunction with pulmonary vein isolation in patients with persistent atrial fibrillation: a meta-analysis comparing cryoballoon vs. radiofrequency energy

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein isolation (PVI) remains the cornerstone of atrial fibrillation (AF) ablation. In patients with persistent AF (PeAF), additional posterior wall ablation (PWA) has been proposed to improve outcomes. Individual small series have included patients ablated with a cryoballoon (CB) and radiofrequency (RF) energy and have yielded controversial results. We conducted a meta-analysis of available data to assess the incremental impact of PWA based on type of energy used for ablation. Objective To evaluate whether PVI + PWA is a more effective approach for treatment of PeAF than PVI alone based on ablation energy used. Methods The online databases (Pubmed, Medline, Embase) were searched using the terms "pulmonary vein isolation", "posterior wall isolation", or "posterior wall ablation". Out of 1917 studies, eight met our strict criteria (Table). Specifically, patients were undergoing de novo ablation for treatment of PeAF using either CB or RF. Patients had PVI alone vs PVI + PWA; studies that delivered additional ablations (except for cavotricuspid isthmus) were excluded. The primary outcome was recurrence of any atrial tachyarrhythmia (AT). Results The cohort consisted of 1607 patients (66 ± 17 years, 75% male); 830 (52%) patients were ablated CB and 777 (48%) patients were ablated with RF (Table). In the CB group, AT recurrence was significantly higher in patients who underwent PVI alone as compared to those who also had additional PWA (OR 2.55, 95% CI [1.89, 3.42], P < 0.0001, Figure). In contrast, in the RF group, outcome between the 2 groups (OR 1.40, 95% CI [0.81, 2.42], P = 0.22, Figure) was similar. Conclusions Addition of CB based PWA to PVI in patients with PeAF undergoing ablation was associated with improved long-term ablation success. However, RF based PVA did not appear to confer the same benefit. Additional randomized studies are needed to determine the impact of ablation energy in patients undergoing PWA during ablation of PeAF.

Pulsed field versus cryoballoon ablation of atrial fibrillation: A comparison of efficacy and safety in a 400 patient cohort

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Boris Schmidt, KR Julian Chun and Stefano Bordignon received speaking honoraria from Medtronic and Boston Scientific Background The cryoballoon (CB) is one of the most commonly used single shot devices for pulmonary vein isolation in patients with atrial fibrillation (AF). Pulsed field ablation (PFA) is a new non-thermal, tissue selective approach for pulmonary vein isolation. Purpose We sought to compare procedural safety and efficacy of these single shot ablation techniques. Methods Consecutive AF patients (paroxysmal / persistent AF) who underwent CB based pulmonary vein isolation (PVI) between November 2020 and February 2022 were enrolled and compared with patients who underwent PFA ablation in the same time period. Patients that underwent ablation beyond PVI (except for cavo-tricuspid isthmus ablation) were excluded. CB PVI was performed using the second-generation CB (CB 28 mm) with 240 sec based freeze protocol and bonus freeze delivery in case of time-to-isolation (TTI) >75 sec. PFA was performed using the Farawave catheter, using the 31 or 35 mm device. All procedures were performed under deep sedation. Results Data from 400 consecutive patients were collected. Most baseline characteristics like age (CB: 67,5 ± 15,3; PFA: 68,4 ± 11; p=0,49), BMI (CB: 28,6 ± 6,3; PFA: 27,9 ± 5,6; p=0,27) and gender (male) (CB: 54%; PFA: 59%; p=0,31) were comparable between the two groups. All PVIs were successfully completed. In 98% (196) of patients in the CB group and 100% (200) in the PFA group, PVI was performed using solely CB or PFA respectively, meaning additional touch up ablation was only needed in 4 CB patients (2%; p=0,044) and 4 veins. Procedure time was significantly shorter in the PFA group (CB: 53 ± 15,3 minutes; PFA: 36,8 ± 13,5 minutes; p<0,001), whereas no difference in fluoroscopy time (CB: 8,1 ± 4,4 minutes; PFA: 7,8 ± 3,3 minutes; p=0,2) was observed. The rate of concomitant CTI-ablation was equal in both groups (CB: 1,5%; PFA: 1,5%; p=1,0). Complication rate was 3,5% with PFA and 6,5% in CB (p=0,17), a difference mostly driven by persistent phrenic nerve palsies (CB: 1,5%; PFA: 0%; p=0,08). All patients are out of the blanking period. There were 80 recurrences in blanking time (CB: 41; PFA: 39; p=0,8). In CB 19,5% of blanking time recurrences were atrial tachycardias compared to 35,9% in PFA (p=0,1). The average time to blanking recurrence was 14,1 ± 21,5 days in CB and 20,5 ± 23,2 in PFA (p=0,2). In total, there were 7 repeat procedures (4 in CB and 3 in PFA; p=0,7) during blanking time due to arrhythmias, despite of antiarrhythmic drugs and/or cardioversion. At the time of this analysis, the first hundred patients in each group reached one-year follow-up. Recurrence free survival after one year for patients with PAF was 82,6% in CB and 80,0% in PFA. In patients with persistent AF it was 70,8% in CB and 67,8% in PFA. Conclusion Cryoballoon and pulsed field ablation are both highly effective and safe techniques for PVI. PFA had a shorter procedure time, whereas the one year follow up was similar for both techniques.

Comparison of various tools for diagnosis of an atrial cardiomyopathy for outcome prediction after pulmonary vein isolation in patients with persistent atrial fibrillation - What is the Holy Grail?

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic Background Atrial cardiomyopathy (ACM) is associated with an increased risk for new-onset atrial fibrillation (AF), progression from paroxysmal to persistent AF-forms and higher arrhythmia recurrence rates after PVI. Therefore, the current ESC guidelines on AF recommend to characterize the underlying ACM to better inform and treat AF patients. Over the past decade, various diagnostic tools were established to diagnose an ACM by analyzing left atrial (LA) structure, and LA electrical and mechanical function. Aim To compare head-to-head electroanatomical mapping (EAM) to assess LA low-voltage substrate (LVS), late gadolinium enhancement (LGE)-MRI to analyse LGE-extent, body surface electrocardiograpghic imaging (ECGI) to measure total atrial conduction time (TACT), digital ECG to analyse amplified p-wave duration (aPWD), and TTE to quantify LA emptying fraction (LA-EF) and LA strain (LAS) regarding ACM diagnosis and outcome prediction after PVI in a homogenous study population. Methods Thirty-six ablation-naive patients (65±9years, 86% male) with persistent AF undergoing PVI were electrically cardioverted prior to PVI and all analyses were performed in sinus rhythm. LGE-MRI, ECGI using a 252-electrode-array, digital ECG and TTE were conducted one day prior to PVI. Subsequently, a high-density LA voltage map (2124±490 sites) was acquired followed by circumferential PVI. MRI-post-processing-analyses were performed by two independent expert laboratories (Marrek for Utah and Adas3D medical for the image-intensity-ratio(IIR)-method). Analysis of aPWD and LAS during reservoir (LASr), conduit (LAScd) and contraction phase (LASct) were performed automatically. Arrhythmia recurrence was recorded within 12 months. Relevant ACM was defined as presence of a LA-LVS≥2cm2 at 0.5mV, a LGE-extent≥20% using the Utah method, a LA-EF<34%, a LASr<23.5%, a LAScd<13.4%, and a LASct<5.4% as described previously. For the IIR-, ECGI-, and automatically measured aPWD-methods, ROC analyses were performed to find the optimal threshold for diagnosis of a relevant ACM as defined in EAM (LA-LVS≥2cm2 at 0.5mV) due to a lack of a predefined threshold. Results A LGE-extent of ≥12% using an IIR cut-off of 1.20, a TACT≥148ms and an automatically measured aPWD≥140ms predicted a relevant ACM as defined in EAM with a sensitivity of 76% and a specificity of 60% for LGE IIR 1.20, a sensitivity of 95% and a specificity of 93% for TACT, and a sensitivity of 86% and a specificity of 80% for aPWD, respectively. Arrhythmia recurrence was significantly higher in patients with a LA-LVS≥2cm2 at 0.5mV, a LGE-extent≥12% at 1.20IIR, a TACT≥148ms, an aPWD≥140ms, a LA-EF<34% and a LASct<5.4%. Conclusion ACM can be diagnosed using EAM, LGE-MRI, ECGI, ECG and TTE and is associated with an increased arrhythmia recurrence rate after PVI. However, only measurement of aPWD in digital ECG, and LA-EF and LAS in TTE are easy, cost-effective, non-invasive methods without any risk for complications.

A novel stepwise approach incorporating ethanol infusion in the vein of Marshall for the ablation of persistent atrial fibrillation.

Apart from pulmonary vein isolation (PVI), several step-by-step procedures that aim to modify left atrial substrate have been proposed for the ablation of persistent atrial fibrillation (AF), yet the optimal strategy remains elusive. There are cumulative data suggesting an incremental benefit of adding vein of Marshall (VOM) ethanol infusion to PVI in patients with persistent AF. We sought to evaluate the feasibility and efficacy of a novel stepwise ablation approach, incorporating a VOM alcoholization step, for persistent AF. In this single-center study, we prospectively enrolled 66 consecutive patients with symptomatic persistent AF and failure of at least one antiarrhythmic drug (ADD). The ablation procedure consisted of (i) PVI, (ii) left atrial segmentation with VOM ethanol infusion and the deployment of linear radiofrequency lesions across the roof and the mitral isthmus and (iii) electrogram-based ablation of dispersion zones. The first two steps were performed in all patients, whereas the third step was carried out only in those still in AF at the end of the second step. Atrial tachycardias during the procedure were mapped and ablated. At the end of the procedure, cavotricuspid isthmus ablation was additionally performed in all patients. The primary endpoint was 12-month freedom from AF and atrial tachycardia after a single procedure and an initial three-month blanking period. Total procedure time was 153 ± 38.5 min. Fluoroscopy time was 16 ± 6.5 min and the radiofrequency ablation time was 26.14 ± 0.26 min. The primary endpoint occurred in 54 patients (82%). At 12 months, 65% of patients were off any AAD. In the univariate Cox regression analysis, left ventricular ejection fraction < 40% was the only predictor of arrhythmia recurrence (HR 3.56; 95% CI, 1.04-12.19; p = 0.04). One patient developed a pericardial tamponade and another a minor groin hematoma. A novel stepwise approach, including a step of ethanol infusion in the VOM, is feasible, safe and provides a high rate of sinus rhythm maintenance at 12 months in patients with persistent AF.

PO-02-030 METHODS, EFFICACY AND SAFETY ON ROUTINE CLINICAL USE OF PULSED FIELD ABLATION FOR PULMONARY VEIN ISOLATION IN PATIENTS WITH ATRIAL FIBRILLATION

Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (AF). It is also used as off-label therapy for persistent AF. Only a few small clinical studies have been published on the mid- and long-term outcome. We present data on methods, efficacy and safety on routine clinical use of pulsed field ablation for pulmonary vein isolation in patients with atrial fibrillation. In patients with AF, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps using a pentaspline diagnostic catheter were performed. Procedural parameters, acute success and in-hospital safety were assessed. A total of 5 operators treated 304 patients (age 67 years (range 32-85), female 42%, BMI 28 kg/m2 (range 20-42), mean CHA2DS2-VaSc score of 2 (range 0-7), first-time ablation 100%, paroxysmal/persistent/longstanding persistent AF 47/17/36%, respectively. Duration since first AF diagnosis was 79 months (range 0-332). Most procedures were performed under deep conscious sedation using propofol and midazolam, without intubation (99%). Pre- and post-ablation high-density maps were performed in 27% of cases. Mean procedure time was 75 min. (range 23–245). Mean left atrial dwell time of the PFA catheter was 25 min. (range 8-98). Fluoroscopy time and dose area product were 18 min. (range 6-50) and 5.74 Gy.cm2 (range 0.40-36.50), respectively. Pulmonary vein isolation (PVI) was successful in 100%. There were no phrenic nerve palsies or esophageal complications. Major complications (2.6%) were pericardial tamponade (2.0%) and stroke (0.7%); one of these strokes was lethal (0.3%). Minor complications (1.0%) were vascular access related (0.7%) and transient ischemic attack (0.3%). In a large, single center cohort of unselected patients, initial experience with de novo PFA for PVI in patients with AF seems to be fast and effective. There were no PFA-specific complications, but the frequency of catheter complications (tamponade, stroke) in this relatively old patient population with a relatively long history of AF demonstrates that there is still room for improvement. The number of complications improved significantly over the course of time, indicating that the learning curve could have negatively influenced the incidence of complications.

AB-452643-2 EARLY PULMONARY VEIN ISOLATION IN PATIENTS WITH HEART FAILURE AND REDUCED EJECTION FRACTION

Atrial fibrillation (AF) and heart failure (HF) often coexist leading to worse outcomes compared to AF or HF alone. According to the current guidelines, pulmonary vein isolation (PVI) as first-line therapy should be considered, however, the optimal timing of the procedure is still unknown. We aimed to investigate the effect of early PVI on all-cause mortality and AF recurrence in patients with HF. We analyzed the data of 162 patients with symptomatic paroxysmal or persistent AF and HF with LVEF < 50% who underwent PVI between 2010 and 2022. The patients’ medical history, laboratory results, echocardiographic and periprocedural parameters were collected in a structured registry. Early PVI was defined as catheter ablation performed within 12 months of AF diagnosis. The median follow-up was 59.7 months, the minimum follow-up was 12 months. Our primary endpoints were AF recurrence after a 3-months blanking period and all-cause mortality at any time during follow-up. Among the 162 patients, 77 (47.5%) experienced AF recurrence and 39 (24.1%) died during follow-up. The median age was 63.2 years. The median LVEF was 40% for early PVI and 37% for deferred PVI. Out of the 63 patients who underwent early PVI, 33 (52%) were taking amiodarone. Patients who underwent early PVI had longer freedom from recurrence compared to late PVI (median 833 days vs. median 696 days, respectively, p=0.02). Early PVI was a negative predictor of AF recurrence (HR: 0.58 [0.32-0.94], p=0.03). Early ablation had no beneficial impact on mortality (p=0.68). However, among those who experienced AF recurrence, repeat ablation was associated with better survival with univariate Cox regression (p=0.01). Furthermore, in multivariate model, repeat ablation was shown to be protective of mortality (HR: 0.312 [0.113-0.865], p=0.03) in the whole cohort. Our study shows that early rhythm control therapy with catheter ablation is more successful compared to deferred PVI in patients with AF and HF. A redo-PVI was associated with better survival, thus a repeat ablation should be considered in case of arrhythmia recurrence in patients with AF and HF to reduce mortality.

Reduction in atrial and ventricular electrical heterogeneity following pulmonary vein isolation in patients with atrial fibrillation

Pulmonary vein isolation (PVI) modulates the intrinsic cardiac autonomic nervous system and reduces atrial fibrillation (AF) recurrence. In this retrospective analysis, we investigated the impact of PVI on ECG interlead P-wave, R-wave, and T-wave heterogeneity (PWH, RWH, TWH) in 45 patients in sinus rhythm undergoing clinically indicated PVI for AF. We measured PWH as a marker of atrial electrical dispersion and AF susceptibility and RWH and TWH as markers of ventricular arrhythmia risk along with standard ECG measures. PVI acutely (16 ± 8.9h) reduced PWH by 20.7% (from 31 ± 1.9 to 25 ± 1.6µV, p < 0.001) and TWH by 27% (from 111 ± 7.8 to 81 ± 6.5µV, p < 0.001). RWH was unchanged after PVI (p = 0.068). In a subgroup of 20 patients with longer follow-up (mean = 47 ± 3.7days after PVI), PWH remained low (25 ± 1.7µV, p = 0.01), but TWH partially returned to the pre-ablation level (to 93 ± 10.2, p = 0.16). In three individuals with early recurrence of atrial arrhythmia in the first 3months after ablation, PWH increased acutely by 8.5%, while in patients without early recurrence, PWH decreased acutely by 22.3% (p = 0.048). PWH was superior to other contemporary P-wave metrics including P-wave axis, dispersion, and duration in predicting early AF recurrence. The rapid time course of decreased PWH and TWH after PVI suggests a beneficial influence likely mediated via ablation of the intrinsic cardiac nervous system. Acute responses of PWH and TWH to PVI suggest a favorable dual effect on atrial and ventricular electrical stability and could be used to track individual patients' electrical heterogeneity profile.

Pulmonary vein isolation in patients with atrial fibrillation and severely dilated left atrium – is it worth it?

Pulmonary vein isolation in patients with atrial fibrillation and severely dilated left atrium – is it worth it?

Clinical outcome of lesion size index-guided high-power radiofrequency catheter ablation for pulmonary vein isolation in patients with atrial fibrillation: 2-year follow-up.

The long-term efficacy of high-power (50 W) ablation guided by lesion size index (LSI-guided HP) for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) remains undetermined. Our study sought to assess the clinical efficacy of LSI-guided HP ablation for PVI in patients with AF and explore the potential predictors associated with clinical outcomes. We consecutively included 186 patients with AF who underwent LSI-guided HP (50 W) ablation at Fuwai Hospital from June 2019 to October 2021. The target LSI values of 4.5-5.5 and 4.0-4.5 at the anterior and posterior walls, respectively, were used in our study. The baseline clinical characteristics, procedural and ablation data, and clinical outcomes were evaluated. The independent potential predictors associated with AF recurrence were further evaluated. The incidence rate of first-pass PVI was 83.9% (156/186). A total of 11 883 lesions were analyzed, and compared with posterior walls of pulmonary veins, anterior walls had significantly lower mean contact force (8.2 ± 3.0 vs. 8.3 ± 2.3 g, p = .015), longer mean radiofrequency duration (16.9 ± 7.2 vs. 12.9 ± 4.5 s, p < .001) and higher mean LSI (4.8 ± 0.2 vs. 4.4 ± 0.2, p < .001). The overall incidence of periprocedural complications was 3.7%, and steam pops without pericardial effusion occurred in three patients (1.6%). During a mean follow-up of 24.0 ± 8.4 months, the overall AF recurrence-free survival was 87.1% after a single procedure. Patients with paroxysmal AF had a higher incidence of freedom from AF recurrence than those with persistent AF (91.2% vs. 80.8%, log-rank p = .034). Higher LSI (HR 0.50, p < .001) and paroxysmal AF (HR 0.39, p = .029) were significantly associated with decreased AF recurrence. By receiver operating characteristic analysis, the LSI of 4.7 and 4.3 for the anterior and posterior walls of the PVs had the highest predictive value for AF recurrence, respectively. LSI-guided HP (50 W) ablation for PVI was an efficient and safe strategy and led to favorable single-procedure 2-year AF recurrence-free survival in patients with AF. Higher LSI and paroxysmal AF were independent predictors of decreased 2-year AF recurrence. The LSI of 4.7 for the anterior wall and 4.3 for the posterior wall of the PVs were the best cutoff values for predicting AF recurrence after LSI-guided HP ablation.

Effect of Left Atrial Pulmonary Vein Angiography on Safety and Efficacy for High-Power, Short-Duration Pulmonary Vein Isolation in Patients with Atrial Fibrillation.

Imaging of pulmonary vein (PV) anatomy by angiography before pulmonary vein isolation (PVI) for atrial fibrillation (AF) has long been standard practice in many centers. Nowadays, very accurate anatomical maps can be generated by the use of high-resolution mapping catheters, and very effective ablation lesions can be generated by the use of the high-power, short-duration (HPSD) technique. In our center, PV angiography was routinely performed before PVI. However, since there is no clear evidence for this, we refrained from performing PV angiography. This study aimed to investigate whether PV angiography is still necessary when using high-resolution mapping catheters after ablation in the high-power, short-duration (HPSD) technique. A total of 139 consecutive patients with atrial fibrillation (66.25 ± 11.68 years old, 62.39% male) undergoing radiofrequency PVI were included in the study. Ablation was performed with the HPSD technique using a fixed protocol for energy delivery of 50 watts (contact force 3-20 g). We observed no significant effect on the efficacy, efficiency and complications of the ablation procedure if pulmonary vein angiography was omitted before HPSD PVI. Thus, using our protocol, it may be useful that PV angiography is avoided, especially in young patients and those with chronic renal disease.

Mechanisms of late arrhythmia recurrence after initially successful pulmonary vein isolation in patients with atrial fibrillation.

Catheter ablation is an effective treatment for atrial fibrillation (AF,) but arrhythmia recurrence occurs in a relevant number of patients. Mechanisms of late occurring arrhythmias after ablation procedures are not fully understood. We analyzed electrophysiological mechanisms of early and late arrhythmia recurrences in patients who underwent radiofrequency-based catheter ablation of AF. Consecutive patients who underwent repeat ablation procedures after initial pulmonary vein isolation (PVI) for symptomatic arrhythmia recurrence were analyzed. A total of 110 consecutive patients who underwent catheter ablation for paroxysmal (79%) or persistent AF (21%) were included. Forty-seven patients suffered from early arrhythmia recurrence (group #1: 3-24 months), 29 patients from mid-term arrhythmia recurrences (group #2: 2-5 years), and 34 patients from late arrhythmia recurrences (group #3:>5 years). Electrical PV reconnection was found in 98% in group #1, 72% in group #2 and 56% in group #3 (p<.001). Mode of arrhythmia recurrence was organized tachycardia in 25%, 28%, and 65% of patients in groups #1, #2, and #3 (p=.001), respectively. Patients with late arrhythmia recurrence had more pronounced left atrial low voltage as compared to patients with early arrhythmia recurrence based on two published scoring system. Electrical PV reconnection was found in the majority of patients with early AF recurrence after PVI. In patients with late arrhythmia recurrences this mechanism may play an inferior role, with many patients presenting without PV reconnection, but with LA structural alterations. Thus, early and late occurring arrhythmia recurrence after catheter ablation may be the same symptom of different diseases.

The first use of POLARx cryoballoon catheter for pulmonary vein isolation in patients with atrial fibrillation: case series

There is the first clinical use of POLARx cryoballoon catheter for pulmonary vein isolation in patients with atrial fibrillation in Russian Federation.

Ultra-microhistological study of nonthermal irreversible electroporation on the esophagus

Esophageal ulceration and even fistula are severe complications of pulmonary vein isolation using traditional thermal ablation. Nonthermal irreversible electroporation (NTIRE) is a new technique for pulmonary vein isolation in patients with atrial fibrillation. NTIRE has been shown to be a safe method for pulsed electroporation near the esophagus. NTIRE preserves the structural framework of the esophagus and allows for rapid recovery of the whole layers of the esophagus. The purpose of this study was to elucidate the ultrastructural changes and cytological mechanisms of cell regeneration and tissue repair after esophageal electroporation. The parameter combination of 2000 V/cm multiplied by 90-pulse output was directly applied to the esophagus in 60 New Zealand rabbits, and ultrastructure analysis of the esophagus was implemented subsequently. NTIRE predominantly triggered apoptosis of esophageal cells shortly after electroporation. Since the tissue structural framework was preserved, esophageal cells could regenerate through self-replication within 4 weeks. Complete anatomical repair can eventually be achieved through structural remodeling, and no lumen stenosis, ulcer, or fistula was observed in the ablated segment. Monophasic, bipolar NTIRE pulses delivered using plate electrodes in an esophageal model demonstrates no irreversible ultra-micropathological changes to the esophagus after 4 weeks.

Abstract 12656: Is the Benefit of Posterior Wall Isolation in Conjunction With Pulmonary Vein Isolation the Same for Patients With Paroxysmal vs. Persistent Atrial Fibrillation - A Meta-Analysis

Introduction: Pulmonary vein isolation (PVI) remains the cornerstone of atrial fibrillation (AF) ablation procedures. Because many patients have continued AF after PVI alone, posterior wall isolation (PWI) has been proposed as an adjunctive strategy to PVI. We conducted a meta-analysis of available data to assess the incremental impact of PWI based on whether patients had paroxysmal or persistent (PAF, PeAF) AF. Objective: To evaluate the incremental impact of PWI following PVI in patients with PAF and PeAF. Methods: The online databases (Pubmed, Medline, Embase) were searched using the terms “pulmonary vein isolation”, “posterior wall isolation”, or “posterior wall ablation”. Out of 1843 studies, 11 met our strict criteria (Table). Specifically, patients were undergoing de novo ablation for treatment of PAF or PeAF using either cryoballoon or radiofrequency energy. Patients had PVI +/- PWI; studies that included additional ablations (except for cavotricuspid isthmus ablation) were excluded. The primary outcome was long-term freedom from recurrence of any atrial tachyarrhythmia (AT). Results: The cohort consisted of 1702 patients (65 ± 18 years, 75% male); 1404 (82%) pts with PeAF and 298 (18%) pts with PAF (Table). In the PeAF group, AT recurrence was significantly higher in patients who underwent PVI alone as compared to those who also had PWI (OR 1.85, 95% CI [1.23, 2.77], P = 0.003, Figure). In contrast, in the PAF group, outcome was similar in patients who did and did not undergo PWI in addition to PVI (OR 0.95, 95% CI [0.53, 1.72], P = 0.86, Figure). Conclusions: PWI was rarely used during the de novo ablation procedure in PAF patients and did not seem to impart additional benefit. In contrast, PeAF patients seemed to derive favorable impact from the addition of PWI to PVI. Additional randomized studies are needed to determine the role of PWI in PeAF patient undergoing de novo ablation for management of AF.