BACKGROUND: Pulsed field ablation (PFA) is a novel, myocardial-selective, non-thermal ablation modality used to target cardiac arrhythmias. Although prompt EGM signal disappearance is observed immediately after PFA application in the pulmonary veins, whether this finding results in adequate transmural lesions is unknown.
OBJECTIVE: If application repetition and catheter-tissue contact impact on lesion formation during PFA.
METHODS: A circular loop PFA catheter was used to deliver repeated energy applications with various levels of contact-force. A benchtop vegetal potato model and a beating heart ventricular myocardial model were utilized to evaluate the impact of application repetition, contact force, and catheter repositioning on contiguity and lesion depth. Lesion development occurred over 18 hours in the vegetal model and over 6 hours in the porcine model.
RESULTS: Lesion formation was found to be dependent on application repetition and contact. In porcine ventricles, single and multiple stacked applications led to a lesion depth of 3.5 ± 0.7 mm and 4.4 ± 1.3 mm, respectively (p =0.002). Furthermore, the greater the catheter-tissue contact, the more contiguous and deeper the lesions in the vegetal model (1.0±0.9 mm with no contact Vs. 5.4±1.4 mm with 30 g of force; p=.0001).
CONCLUSIONS: PFA delivered via a circular catheter showed that both repetition and catheter contact led independently to deeper lesion formation. These findings indicate that endpoints for effective PFA ablation are more related to PFA biophysics than mere EGM attenuation.

BACKGROUND: Despite improvement in treatment strategies for atrial fibrillation (AF), a significant proportion of patients still experience recurrence after ablation. This study aims to propose a novel algorithm based on Transformer using surface electrocardiogram (ECG) signals and clinical features can predict AF recurrence.
METHODS: Between October 2018 to December 2021, patients who underwent index radiofrequency ablation for AF with at least one standard 10-second surface ECG during sinus rhythm were enrolled. An end-to-end deep learning framework based on Transformer and a fusion module was used to predict AF recurrence using ECG and clinical features. Model performance was evaluated using areas under the receiver operating characteristic curve (AUROC), sensitivity, specificity, accuracy and F1-score.
RESULTS: A total of 920 patients (median age 61 [IQR 14] years, 66.3% male) were included. After a median follow-up of 24 months, 253 patients (27.5%) experienced AF recurrence. A single deep learning enabled ECG signals identified AF recurrence with an AUROC of 0.769, sensitivity of 75.5%, specificity of 61.1%, F1 score of 55.6% and overall accuracy of 65.2%. Combining ECG signals and clinical features increased the AUROC to 0.899, sensitivity to 81.1%, specificity to 81.7%, F1 score to 71.7%, and overall accuracy to 81.5%.
CONCLUSIONS: The Transformer algorithm demonstrated excellent performance in predicting AF recurrence. Integrating ECG and clinical features enhanced the models\' performance and may help identify patients at low risk for AF recurrence after index ablation.

OBJECTIVE: The CABANA study shows that atrial fibrillation (AF) paitents younger than 65 years benefit more from the AF radiofrequency catheter ablation (RFCA) procedure. The aim of this study is to investigate the impact of inherent patent foramen ovale (PFO) with a Left-to-Right Shunt on the RFCA procedure in young AF patients.
METHODS: Based on the presence or absence of inherent PFO, the AF patients were divided into the PFO groups and the non-PFO group. Clinical follow-up was also investigated.
RESULTS: A total of 285 AF patients were enrolled. PFO was detected by TEE in 42 patients. The age of patients at initial AF onset was younger in the PFO group than in the non-PFO group (58.3 ± 8.9 vs. 62.3 ± 9.6 years, P = 0.012). There were more AF patients aged <55 years in the PFO group than in the non-PFO group. For the 9 AF patients with PFO who experienced AF recurrence and the left-to-right shunts decreased in size in 5 of the patients aged <65 years. The LAD decreased in those patients. In the PeAF patients, 53/64 patients aged <65 years and 23/40 patients aged older than 65 years were free of AF (82.8 % vs. 57.5 %, respectively; P = 0.005).
CONCLUSIONS: Success is not affected when AF is combined PFO compared with AF without PFO. Young patients have better PeAF RFCA outcomes. AF in young patients with left atria enlargement and a serious AF burden, may lead to reduced EF and render PFO easy to detect.

OBJECTIVE: Pulsed field ablation (PFA) is an emerging non-thermal ablative modality demonstrating considerable promise for catheter ablation of atrial fibrillation (AF). However, these PFA trials have almost universally included only Caucasian populations, with little data on its effect on other races/ethnicities. The PLEASE-AF trial sought to study the 12-month efficacy and the safety of a multi-electrode hexaspline PFA catheter in treating a predominantly Asian/Chinese population of patients with drug-refractory paroxysmal AF.
RESULTS: Patients underwent pulmonary vein (PV) isolation (PVI) by delivering different pulse intensities at the PV ostium (1800 V) and atrium (2000 V). Acute success was defined as no PV potentials and entrance/exit conduction block of all PVs after a 20-min waiting period. Follow-up at 3, 6, and 12 months included 12-lead electrocardiogram and 24-h Holter examinations. The primary efficacy endpoint was 12-month freedom from any atrial arrhythmias lasting at least 30 s. The cohort included 143 patients from 12 hospitals treated by 28 operators: age 60.2 ± 10.0 years, 65.7% male, Asian/Chinese 100%, and left atrial diameter 36.6 ± 4.9 mm. All PVs (565/565, 100%) were successfully isolated. The total procedure, catheter dwell, total PFA application, and total fluoroscopy times were 123.5 ± 38.8 min, 63.0 ± 30.7 min, 169.7 ± 34.6 s, and 27.3 ± 10.1 min, respectively. The primary endpoint was observed in 124 of 143 patients (86.7%). One patient (0.7%) developed a small pericardial effusion 1-month post-procedure, not requiring intervention.
CONCLUSIONS: The novel hexaspline PFA catheter demonstrated universal acute PVI with an excellent safety profile and promising 12-month freedom from recurrent atrial arrhythmias in an Asian/Chinese population with paroxysmal AF.
BACKGROUND: ClinicalTrials.gov Identifier: NCT05114954.

UNASSIGNED: Radiofrequency catheter ablation (RFCA) has been shown to have low efficacy for the treatment of persistent atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). We conducted this study to evaluate the benefit of adjunctive vein of Marshall (VOM) ethanol infusion during RFCA for persistent AF (PsAF) in patients with non-obstructive HCM.
UNASSIGNED: This multicenter retrospective observational study included 102 consecutive non-obstructive HCM patients with PsAF who underwent RFCA plus VOM ethanol infusion (VOM-EI) (RFCA + VOM, n = 56) or RFCA alone (RFCA, n = 46) for the first time. The efficacy endpoint was survival without AF or atrial tachycardia (AT) after the blanking period.
UNASSIGNED: We completed the VOM-EI in 92.9% (52/56) patients. The left pulmonary vein antrum ablation time (RFCA + VOM: 19.9 ± 6.1 min vs. RFCA: 27.2 ± 9.3 min), mitral isthmus (MI) ablation time (RFCA + VOM: 16.9 ± 3.7 min vs. RFCA: 28.4 ± 7.8 min), and rate of coronary sinus (CS) vein ablation (RFCA + VOM: 57.69% vs. RFCA: 80.43%) were lower but the acute success rate of MI block (RFCA + VOM: 98.1% vs. RFCA: 84.8%) were higher in the RFCA + VOM group than those in the RFCA group (all p < 0.05). After twelve months follow-up, 84.6% of patients (44/52) survived without AF/AT in the RFCA + VOM group, compared to 65.2% of patients (30/46) in the RFCA group (p = 0.03; odds ratio = 2.93, 95% CI: 1.18-7.79).
UNASSIGNED: VOM-EI combined with RFCA decreased the recurrence rate of AF/AT at 12 months in HCM patients with PsAF. VOM-EI simplified the ablation of the left pulmonary vein antrum and MI and increased the success rate of MI bidirectional block.

Pulsed field ablation with irreversible electroporation for the treatment of atrial fibrillation involves tissue-specific and non-thermal energy-induced cell necrosis, which helps avoid complications, such as pulmonary vein stenosis, atrial collateral tissue damage, and extensive atrial structural damage, often encountered with traditional thermal ablation. In existing clinical trials, pulsed field ablation has shown excellent effects on pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation. Pulsed field ablation is easy, simple, and quick and can reduce iatrogenic injury. Therefore, the application of pulsed field ablation technology in the treatment of atrial fibrillation has a promising future. Notably, the adjustment of parameters in pulsed field ablation with different ablation catheter systems can strongly affect the area and depth of the necrotic myocardium, which greatly affects the likelihood of atrial fibrillation recurrence and incidence of adverse complications after ablation. In this paper, we review the mechanisms, advantages, and limitations of pulsed field ablation based on the results of a series of previous studies and provide ideas and directions for future research.

UNASSIGNED: Although pulmonary vein isolation (PVI) remains the mainstream way of atrial fibrillation (AF) ablation. The left atrial posterior wall (LAPW) may contributes to the development of AF as an arrhythmogenic substrate. The efficacy of additional left atrial posterior wall isolation (LAPWI) beyond PVI is in AF patients remains undefined. This study explored the influence of posterior wall isolation (PWI) on clinical outcomes in AF patients.
UNASSIGNED: PubMed, EMBASE, and Cochrane Library databases were searched for studies comparing the outcomes of AF with and without PWI. The efficacy outcomes were recurrence of all atrial arrhythmia (AA), atrial fibrillation (AF), and atrial flutter (AFL)/atrial tachycardia (AT). The safety outcomes were mainly focused on procedural adverse events.
UNASSIGNED: A total of 16 studies (7 randomized controlled trials (RCTs), 3 prospective studies and 6 retrospective analyses) with 3340 AF patients were enrolled (1550 patients in PVI with PWI group and 1790 in PVI alone group). 12 studies included persistent atrial fibrillation patients, 3 studies with paroxysmal AF patients and 1 study with paroxysmal AF and persistent AF concurrently. Mean follow-up period was 16.56 months. In AF patients, adjunctive PWI obviously reduced the recurrence of all atrial arrhythmias (risk ratio (RR) 0.78 [95% CI 0.64-0.95], I 2 = 79%, p = 0.01) and the recurrence of AF (RR 0.68 [95% CI 0.53-0.88], I 2 = 75%, p = 0.004); Meanwhile, additional PWI left no impact substantially on lower recurrence of AFL/AT (RR 1.23 [95% CI 0.94-1.60], I 2 = 49%, p = 0.12). The results seemed to be no significant differences in occurrence rate of procedural complications between the PVI only and PWI+PVI (RR 1.19 [95% CI 0.80-1.79], I 2 = 0%, p = 0.39). In subgroup analyses, the benefit of adjunctive PWI compared with PVI only was more distinct in persistent AF group and cryoballoon ablation group. Notably, adjunctive PWI with radiofrequency ablation may induce a slight increase of recurrent AFL/AT compared with PVI only (RR 1.56 [95% CI 1.02-2.39], I 2 = 30%, p = 0.04).
UNASSIGNED: Compared with PVI alone, additional PWI to PVI appeared to be associated with decreased recurrence of AF and atrial arrhythmias without an increased occurrence of procedural complications, especially in persistent AF patients. Cryoballoon ablation seemed more suitable for PWI compared with radiofrequency ablation. More RCTs are needed to verify the conclusion.

OBJECTIVE: Pulsed field ablation (PFA) is an emerging non-thermal ablative modality demonstrating considerable promise for catheter ablation of atrial fibrillation (AF). However, these PFA trials have almost universally included only Caucasian populations, with little data on its effect on other races/ethnicities. The PLEASE-AF trial sought to study the 12-month efficacy and the safety of a multi-electrode hexaspline PFA catheter in treating a predominantly Asian/Chinese population of patients with drug-refractory paroxysmal AF.
RESULTS: Patients underwent pulmonary vein (PV) isolation (PVI) by delivering different pulse intensities at the PV ostium (1800 V) and atrium (2000 V). Acute success was defined as no PV potentials and entrance/exit conduction block of all PVs after a 20-min waiting period. Follow-up at 3, 6, and 12 months included 12-lead electrocardiogram and 24-h Holter examinations. The primary efficacy endpoint was 12-month freedom from any atrial arrhythmias lasting at least 30 s. The cohort included 143 patients from 12 hospitals treated by 28 operators: age 60.2 ± 10.0 years, 65.7% male, Asian/Chinese 100%, and left atrial diameter 36.6 ± 4.9 mm. All PVs (565/565, 100%) were successfully isolated. The total procedure, catheter dwell, total PFA application, and total fluoroscopy times were 123.5 ± 38.8 min, 63.0 ± 30.7 min, 169.7 ± 34.6 s, and 27.3 ± 10.1 min, respectively. The primary endpoint was observed in 124 of 143 patients (86.7%). One patient (0.7%) developed a small pericardial effusion 1-month post-procedure, not requiring intervention.
CONCLUSIONS: The novel hexaspline PFA catheter demonstrated universal acute PVI with an excellent safety profile and promising 12-month freedom from recurrent atrial arrhythmias in an Asian/Chinese population with paroxysmal AF.
BACKGROUND: ClinicalTrials.gov Identifier: NCT05114954.

BACKGROUND: Patent foramen ovale (PFO) affects 20%-34% of adults and is associated with strokes and other disorders. The conventional treatment of PFO-related strokes is a closure procedure. The metal device is associated with some adverse events.
OBJECTIVE: Our aim was to investigate the efficacy and safety of PFO closure using cryoablation without implantation in patients with atrial fibrillation (AF) who underwent pulmonary vein isolation (PVI).
METHODS: We divided the 22 patients with both PFO and AF who underwent PVI via cryoablation into 2 groups: standard PVI + atrial septal (AS) cryoablation group (group 1, n = 11) and standard PVI group (group 2, n = 11). The guidewire accesses the left atrium through the PFO without AS puncture during the procedure. Standard PVI via cryoablation was performed. The cryoballoon was retracted to the right atrium and inflated against the AS post-PVI. Patients in group 1 had cryoablation for 120-150 seconds, whereas patients in group 2 received sham ablation. The co-primary end points were the PFO closure rate and a composite of AF recurrence and stroke/transient ischemic attack (TIA) events.
RESULTS: There were no differences in procedure-related adverse events between the 2 groups. Neither group had an ischemic stroke report at 1-year follow-up. The PFO closure rate at 6 months in group 1 was significantly higher than that in group 2 (7 [63.6%] vs 1 [9.1%]; P = .002). AF recurrence post ablation was comparable in both groups at 3 months (3 [27.3%] vs 1 [9.1%]; P = .269), 6 months (0 vs 0), and 12 months (2 [18.2%%] vs 1 [9.1%]; P = .534) of follow-up.
CONCLUSIONS: Cryoablation is a safe and effective approach to close PFO in patients with AF undergoing PVI in a single procedure.

BACKGROUND: Catheter ablation for atrial fibrillation (AF) including pulmonary vein isolation and possibly further substrate ablation is the most common electrophysiological procedure. Severe complications are uncommon, but their detailed assessment in a large worldwide cohort is lacking.
OBJECTIVE: The aim of this study was to determine the incidence of periprocedural severe complications and to provide a detailed characterization of the diagnostic evaluation and management of these complications in patients undergoing AF ablation.
METHODS: Individual patient data were collected from 23 centers worldwide. Limited data were collected for all patients who underwent catheter ablation, and an expanded series of data points were collected for patients who experienced severe complications during periprocedural follow-up. Incidence, predictors, patient characteristics, management details, and overall outcomes of patients who experienced ablation-related complications were investigated.
RESULTS: Data were collected from 23 participating centers at which 33,879 procedures were performed (median age 63 years, 30% women, 71% radiofrequency ablations). The incidence of severe complications (n = 271) was low (tamponade 6.8‰, stroke 0.97‰, cardiac arrest 0.41‰, esophageal fistula 0.21‰, and death 0.21‰). Age, female sex, a dilated left atrium, procedure duration, and the use of radiofrequency energy were independently associated with the composite endpoint of all severe complications. Among patients experiencing tamponade, 13% required cardiac surgery. Ninety-three percent of patients with complications were discharged directly home after a median length of stay of 5 days (Q1-Q3: 3-7 days).
CONCLUSIONS: This large worldwide collaborative study highlighted that tamponade, stroke, cardiac arrest, esophageal fistula, and death are rare after AF ablation. Older age, female sex, procedure duration, a dilated left atrium, and the use of radiofrequency energy were associated with severe complications in this multinational cohort. One in 8 patients with tamponade required cardiac surgery.