Pulmonary Vein Reconnection Research Articles

Durability of pulmonary vein isolation after radiofrequency-balloon ablation

Abstract Aims Recently a multi-electrode radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) was introduced. To the best of our knowledge no data on PVI durability has yet been published. Objectives The aim of this single-center study was to investigate the incidence of pulmonary vein (PV) reconnectionafter RFB-guided PVI. Methods Patients undergoing second ablation for recurrent atrial tachyarrhythmia (ATa) following the initial RFB-PVI were investigated. Left arial (LA) electroanatomic mapping was used. The rate of PV reconnection, the type of recurrent ATaand procedural data were analyzed. Results Among 178 patients treated with RFB, 21 patients underwent a second procedure 11 ± 6 months after the initial PVI. 67% of these patients presented with atrial fibrillation (AF), 33% with atrial tachycardia. Regarding baseline characteristics, 71% of these patients were male, mean age was 67±10, mean BMI was 28±5, 67% had hypertension and 33% had coronary artery disease. Overall, 83 PVs including one left common PV (LCPV) were assessed. The rate of PV reconnection was 28% (23/83 PVs). 57% of patients (12/21) had at least one reconnected PV. Patient with PV-reconnection had more AF recurrence and less often atrial tachycardia (AT) (AF: 75%, AT: 25%) than patients with durably isolated PVs (AF: 56%, AT: 44%). Most reconnections were detected in septal PVs. Reconnections were distributed as follows: RIPV: 8/21, RSPV: 7/21, LIPV: 5/20, LSVP: 3/20, LCPV: 0/1. Precise localization of the gaps could be identified in 15/23 PVs. Most common gap locations were at the anterior carina (4/15) for septal PVs and anterior-inferior (3/15) at the LIPV. Ablation strategy was pure PV reisolation in 8/12 patients and PV reisolation with additional linear lesions in 4/12 patients. All patients with durably isolated PVs were treated with additional substrate modification. In total, following additional lesions were set: anterior line: 6, roof line: 11, cavotricuspid isthmus (CTI): 7, LAA-Isolation: 1, free wall of the right atrium: 1. Regarding procedural data of the index procedure, the number of applications was not a statistically significant predictor of reconnection (p=0.77). Conclusion We provide the first insight into durability of PVI after radiofrequency-balloon ablation. 72% of all PVs were still isolated. Our data on gap localization might help to identify regions where optimal balloon contact is difficult to achieve. More data on this topic might reveal predictors for PV reconnections.

Pulsed electric field, cryoballoon, and radiofrequency for paroxysmal atrial fibrillation ablation: a propensity score-matched comparison

Abstract Background and Aims Pulmonary vein isolation (PVI) is the most effective rhythm control strategy in paroxysmal atrial fibrillation (AF). Pulsed field ablation (PFA) has emerged as a novel, non-thermal energy source to selectively ablate cardiac tissue. We report the first multicenter experience on PVI via the pentaspline FarapulseTM PFA system versus thermal-based technologies in a propensity score-matched population of paroxysmal AF patients. Methods Propensity score matching was adopted to compare PVI-only ablation outcomes via the FarawaveTM PFA system (Group PFA), cryoballoon ablation (Group CRYO), or focal radiofrequency (Group RF) (PFA:CRYO:RF Ratio=1:2:2). Results Among 1572 (mean age: 62.4±11.3 years; 42.5% females) PAF patients undergoing their first time PVI with either PFA (n=174), CRYO (n=655), or RF (n=743), propensity score matching yielded 174 PFA, 348 CRYO, and 348 RF patients. First-pass isolation was achieved in 98.8% of pulmonary veins (PVs) with PFA, 81.5% with CRYO, and 73.1% with RF (p<0.001). Procedural and dwell times were significantly shorter with PFA. Overall complication rates were 3.4% (n=6) with PFA, 8.6% (n=30) with CRYO, and 5.5% (n=19) with RF (p=0.052). The 1-year Kaplan-Meier estimated freedom from any atrial tachyarrhythmia was 79.3% with PFA, 74.7% with CRYO, and 72.4% with RF (log-rank p-value: 0.24). Among 145 repeat ablation procedures, PV reconnection rate was 19.1% after PFA, 27.5% after CRYO, and 34.8% after RF (p=0.01). Conclusion PFA contributed to significantly shorter procedural times. Follow-up data showed a similar arrhythmia freedom among groups, although a higher rate of PV reconnection was documented in post-CRYO and post-RF redo procedures.RecurrencePVs

Incidence, types, and predictors of AF recurrence after AF ablation with pulsed field ablation. A single-centre experience

Abstract Background Pulsed field ablation (PFA) is an emerging method for the ablation of atrial fibrillation (AF). As there are few data on incidence, types, and predictors of AF recurrence after PFA for AF ablation, we are continuously analysing our cohort. Methods We report our outcome data after PVI with PFA. Each procedure was performed under deep sedation with propofol and fentanyl. Before transeptal puncture, unfractionated heparin was administered to maintain an ACT level >300sec throughout the procedure. Isolation of pulmonary veins was started after administration of 1mg of atropine with 8 applications per vein (4 in basket, 4 in flower configuration). In recent months we have routinely performed 2 additional ablations in flower configuration with an anterior twist at both right pulmonary veins. All veins were checked for entrance- and exitblock to confirm isolation in sinus rhythm. An additional ablation was performed if necessary. Results In total, 231 patients were analysed. Mean age was 62±10 years, 38% were female. Mean CHADS-VASc score was 2±1. 61% had paroxysmal AF (PAF), 36% persistent AF, and 3% patients had long-standing persistent AF. In 85% (n=197) first-pass isolation of all veins was possible. Primary PV isolation was achieved in all patients at the end of the procedure. In addition to PVI, the cavo-tricuspid isthmus (CTI) was blocked in 6% (using radiofrequency ablation in case of previously or during the procedure documented typical flutter) and the posterior wall was isolated in another 6% during the first procedure. Mean procedure time was 60±20 minutes (24-175 minutes), mean X-ray time 19±9 minutes. In 231 procedures, only two catheter-associated complications were documented. 38 patients (16%) had arrhythmia recurrence after a blanking period of 3 months and a mean follow-up of 273±177 days. Mean time to recurrence was 171±84 days. Women were more likely to have recurrences [OR 2.042 (CI 95% 1.012-4.121), p<0,05]. Patients who had undergone any type of cardiac surgery prior to ablation were also significantly more likely to have recurrence [OR 0.517 (CI 95% 0.116-0.212); p<0.001]. Patients with no other comorbidities were more likely to remain free from arrhythmias [OR 0.792 (95% CI 0.736-0.853); p<0,01]. The type of AF did not make a significant difference according to the risk of recurrence in this cohort. To date, we have performed 18 re-do procedures in patients after PVI with PFA. The recurrent arrhythmia was AF in 39% (n=7), atypical AT in 50% (roof-dependent: 28%, n=5; mitral isthmus dependent: 22%, n=4), and CTI-dependent flutter in 39% (n=7). All but one patient had PV reconnections, and all were successfully reablated. Conclusion PFA success rate is similar to that of thermal techniques. Procedure time is shorter in experienced operators and the complication rate is low in our cohort. Results from RCTs are needed to further evaluate this new method compared to other ablation techniques.

Pulmonary vein isolation with the radiofrequency balloon catheter: long-term results and predictors of ablation success

Abstract Background The novel multielectrode radiofrequency balloon catheter (RFB) has been demonstrated to achieve safe and effective pulmonary vein isolation (PVI). However, data on long-term ablation outcomes is lacking. Purpose This single-centre study aimed to evaluate the efficacy of the RFB beyond 1-year follow-up and define predictors of arrhythmia recurrence. Methods All consecutive patients with symptomatic paroxysmal atrial fibrillation (AF) undergoing first-time PVI with the RFB between January 2021 and November 2022 were prospectively included. Post-ablation remapping was systematically employed to confirm PVI at the end of the procedure. Procedural failure was defined as any atrial tachyarrhythmias (ATas) lasting >30 s occurring during the follow-up after a 3-month blanking period (BP). Patient characteristics, procedural parameters, and ATas recurrence during BP were analysed with respect to ablation outcome. Results A total of 120 consecutive patients (50 female, 42%; mean age 65±12 years) were enrolled. After a mean follow-up of 16.1±7.9 months, ATas recurrence occurred in 30 patients (25%). ATas were adjudicated as AF in 25 patients (83.3%) and as atrial tachycardia/atrial flutter in 5 patients (16.7%). The mean time from the index procedure to ATas recurrence was 203±130 days. A redo procedure was performed in 17 patients (56.7%) and at least one PV reconnection was observed in 12 patients (70.6%). Patients with ATas recurrence presented higher values of body mass index (31.0 ±5.7 vs. 28.1±4.9 kg/m2, p=0.048), larger left atria (43±11 vs. 35±9 ml/m2, p=0.003), and increased rates of ATas recurrence during the BP (53.3% vs. 2.2 %, p<0.001) compared to patients with persistent sinus rhythm. At multivariable Cox regression analysis, left atrial end-systolic volume index and ATas recurrence during the BP were independently associated with procedural failure (HR 1.05, 95%CI 1.00-1.11, p=0.048 and HR 23.88, 95%CI 7.71-73.99, p<0.001, respectively). Conclusion At 16 months follow-up, PVI with the RFB resulted in freedom from arrhythmia relapse in 75% of patients. Left atrial end-systolic volume index and ATas recurrence during the BP were independent predictors of arrhythmia recurrence.ATas-free survivalPredictors of ATas recurrence

First multicenter experience of pulmonary vein and posterior wall isolation via a novel focal 9mm lattice tip catheter in a real-world scenario

Abstract Background Pulsed field ablation (PFA) is an innovative technology recently adopted for the treatment of atrial fibrillation (AF). Preclinical and clinical studies have reported a remarkable safety profile, as a result of its tissue specific effect targeting cardiomyocytes and sparing adjacent tissues. The AfferaTM system is a focal 9-mm lattice tip catheter that has recently received regulatory approval. No data currently exist on the feasibility of this technology for first-time pulmonary vein isolation (PVI) and posterior wall isolation (PWI) in a real-world scenario. Objective To evaluate the safety and efficacy of the focal 9-mm lattice tip catheter Sphere-9 (Affera Inc) in a real-world population undergoing PVI and PWI. Methods Consecutive AF patients undergoing first-time PVI plus PWI with the AfferaTM system in two different centres between August and November 2023 were prospectively included. PFA was always used to ablate the posterior left atrium, whereas anterior applications were performed using either radiofrequency energy (RF/PF strategy) or PFA (PF/PF strategy) based on operator's discretion. Primary efficacy endpoint was acute procedural success (successful PVI with evidence of bidirectional block at the end of the procedure). Primary safety endpoint included major technology-related complications occurring within 7 days post-ablation. Secondary endpoints were first pass isolation, acute reconnection, overall complications, procedural, dwelling, and fluoroscopy time. Results Thirty consecutive patients [mean age: 68±6.8 years; 61.7% males; CHA2DS2-VASc Score 2.0 (1.5 – 3.5)] were included. Among them, 66.7% (n=20) had non-paroxysmal AF. PVI was performed with an RF/PF strategy or PF/PF one in 10 (33.3%) and 20 (66.7%) patients, respectively. Posterior wall isolation (PWI) was performed in 30 (100%) cases. The primary endpoint was achieved in 100% of patients for both PVI and PWI with average procedural time of 95 min (77-120 min), dwelling time of 78 min (55-92 min) and fluoroscopy time of 6 min (5-10.5 min) (Figure 1). No technology-related complications were observed. First-pass isolation occurred in 100% of PVI and PWI, with no acute reconnection for PW and 1 case of right PV reconnection in the RF/PF strategy group. Conclusions AF ablation with the focal 9-mm lattice tip catheter Sphere-9 confirmed high efficacy and safety in PVI + PW in a real-world population.Figure 1

Improved procedural workflow for catheter ablation of paroxysmal AF with high density mapping system and advanced technology: insights from a multicenter, international study

Abstract Background A high incidence of pulmonary vein (PV) reconnection has been reported in patients with clinical recurrences of AF. Low-voltage activity beyond PVs (e.g. antral activity potentials, RAP) likely represent vulnerabilities in antral lesion sets and they may contribute to ablation failures. Purpose The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions. Methods DELETE AF is a prospective, single-arm, international post-market cohort study. Consecutive patients from 10 centers who were undergoing radiofrequency ablation of paroxysmal AF were included. The Lumipoint map-analysis tool was used sequentially on each PV component. Post-ablation, all patients were monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Additional ECG monitoring were performed as indicated by patient symptoms. The ablation endpoint was PV isolation (PVI). Long-term outcome was the recurrence of AF over follow-up. Data are reported as median [IQ range]. Results One-hundred ten cases of AF ablation were analyzed: 28 (25.5%) females, age=63[56-69] years, 24 (21.8%) patients with a history of AT/AFL. The procedure duration was 58[24-76] min (RF delivery time=18[12-28] min, number of ablation spots=77[44-101]) and the fluoroscopy time was 13[9-19] min. Thirty-eight (34.5%) were repeat ablation: in these patients after initial mapping a total of 114 PV gaps (PVGs) in 29 (76.3%) patients and 69 RAPs in 15 patients (39.5%) were found. After ablation, a total of 5 early PVGs in 2 (1.8%) patients (all in de novo procedures) and a total of 10 RAPs in 7 (6.3%) patients (3 out 38 -7.9%- of repeat ablations vs 4 out 72 -5.6%- of de novo cases, p=0.690) were detected after first remapping. Each residual PVG was first targeted and additional focal ablations were performed at any low-voltage propagation suspected within the region of previous antral ablation. Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients except for one that still exhibited a residual low-voltage antral signal after adenosine infusion with no PV conduction. Eighty-six (78.2%) patients had complete follow-up information. During the 90-day blanking period, 8 (9.2%) patients experienced an early recurrence. After the blanking period, over a follow-up of 357[190-380] days, 13 patients (15.1%) suffered an AF recurrence (time to recurrence: 207[144-300] days). No major complications or adverse events occurred. Conclusion A structured ablation workflow for catheter ablation, with consistent high-density mapping and improved diagnostic tools to guide the ablation, proved to be safe and effective in paroxysmal AF.

Strategies for recurrent atrial fibrillation in patients despite durable pulmonary vein isolation

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone in treatment of atrial fibrillation (AF). Despite initially successful PVI patients experience recurrence of AF mostly due to reconnection of pulmonary veins (PVs). However, a certain number of patients presents with recurrent AF despite durable PVI. The optimal ablation strategy for these patients has yet to be discerned. Aim The aim of this study was to compare outcomes for different ablation strategies for recurrent AF despite persistent PVI. Methods All redo procedures for recurrence of AF from 01/2016 – 6/2022 at our center were analyzed. Only patients with proven durable PVI (entrance/exit block and high density (HD) mapping) were included. Patients were excluded, if re-PVI or right atrial ablation was necessary. In all procedures (HD) 3-D mapping and radiofrequency ablation were performed. Ablation strategy was at operators’ discretion. A 12-month follow up (FU) was obtained. Results A total of 405 left-atrial procedures for the recurrence of AF were analyzed. In 85 (21.0%) procedures all PVs were still isolated. Of these 30 patients (35.3 %) were female and 70 patients (82.4 %) suffered from persistent AF. In 49 patients (57.6 %) LA scar was detectable (85.7 % persAF). The ablation strategies consisted of: roof line (n=9; 10.6 %), left atrial anterior line (n=8, 9.4 %), roof line and left atrial anterior line (n=8, 9.4%), roof line and left atrial inferior line (n=18, 21.2 %), box lesion (n=6, 7.1 %), other left atrial ablation lines (n=20, 23.5 %) and substrate modification (CFAE and substrate encirclement) (n=16, 18.8 %). In patients with PAF (n=15), 3 patients received a roof line (20.0 %), 3 patients received the latter and left atrial inferior line (20.0 %), 5 patients received other left atrial ablation lines (33.3 %) and 4 patients received substrate modification (CFAE and substrate encirclement) (26.7 %). After a mean follow up of 401 +/- 125 days 55.3 % (n=47) of patients were free from any atrial arrhythmia (roof line 77.8 +/- 15 %, left atrial anterior line 87.5 +/- 13 %, roof line and left atrial anterior line 37.5 +/- 18 %, roof line and left atrial inferior line 50 +/- 12 %, box lesion 83.3 +/- 17 %, other left atrial ablation lines 45.0 +/- 11 %, substrate modification (CFAE and substrate encirclement) 43.8 +/- 13 %, p=0.122), 35.3 % (n=30) showed recurrence of AF (p=0.287) and 9.4 % (n=8) showed atrial tachycardia (AT) (p=0.693). None of the ablation strategies led to a significantly superior outcome. Conclusion In patients suffering from recurrence of AF despite durable pulmonary vein isolation different substrate modification strategies did not show any superiority for one or the other. Despite the necessity of additional ablation beyond PVI the optimal ablation strategy needs to be yet determined to improve outcome for redo procedures.

How to easily detect residual conduction gaps in redo procedure of pulmonary vein isolation: Post Encircling Mapping (PEM)

Abstract Background Pulmonary vein isolation (PVI) is the cornerstone of the interventional catheter-based treatment of atrial fibrillation. Unfortunately, persistent pulmonary vein isolation is difficult to achieve, and up to 70% of pulmonary vein reconnection rate has been documented (1). Atrial mapping during pacing from CS in combination with LAT (local activation time) mapping may help to identify these residual gaps (2). Methods We collected data from consecutive radiofrequency (RF) redo PVI procedures performed in our center from 01/01/2022 to 01/10/2023. Re-isolation was obtained based on bipolar map and Local Activation Time (LAT) map during pacing from distal coronary sinus (CS) -table 1 for the workflow-. We compared data obtained from analysis of bipolar maps and LAT maps; "discrepancy" between bipolar map and LAT map was defined as a difference which may lead to a different approach to the ablation strategy (figure 1); then, we compared procedural timing (radiofrequency time, fluoroscopy time, and skin-to-skin time) with our historical cohort of RF redo PVI procedures (01/01/2011 – 31/12/2021). Results We performed 34 radiofrequency redo procedure from 01/01/2022 to 01/10/2023. In 13 out of 112 veins treated (11.6%), we observed discrepancy between bipolar map and LAT map. We observed a lower radiofrequency time for patients treated on the basis of LAT map (01-01-2022 – 01-10-2022) when compared with our historical cohort (1023.21 ± 521.51 sec vs 1358.50 +/- 746.53 sec, p= 0.038); no differences were found in terms of skin-to-skin time and fluoroscopy time. Conclusions To perform a LAT map during pacing from distal CS may help to better identify residual gaps in redo AF procedures, allowing a reduction in radiofrequency time, without increasing skin to skin time and fluoroscopy time.Discrepancy between bipolar and LAT map

Acute and long-term lesion durability and reconnection patterns following hybrid atrial fibrillation ablation

Abstract Background/introduction Hybrid ablation (AF) is a well-established rhythm control strategy in non-paroxysmal AF patients and can be performed as a staged or one-step epicardial-endocardial approach. Data on need for endocardial touch-up acutely after epicardial ablation are limited, as well as long-term reconnection patterns in patients undergoing redo procedures. Purpose to evaluate the lesion transmurality detected via endocardial mapping acutely after epicardial radiofrequency (RF) ablation, as well as anatomical and clinical predictors of residual endocardial gaps in a large cohort of patients undergoing hybrid AF ablation. Furthermore, long-term lesion durability will be assessed in patients undergoing repeat endocardial ablation. Methods Hybrid procedures were performed in a one-step fashion (endocardial mapping +/- ablation immediately following left thoracoscopy epicardial ablation). Epicardial pulmonary vein (PV) isolation was achieved via a bipolar RF clamp; further epicardial linear ablation was performed with a RF bipolar linear device. Additional lesions were performed according to physician’s preference on a patient basis. At the end of the procedure, the left atrial appendage (LAA) was clipped. Results A total of 130 patients were included (mean age: 65±9.4; 72.3% males); among them, 19.2% and 55.4% had persistent or long-standing persistent AF. All patients received epicardial PV and posterior wall (PW) isolation plus additional RF applications to the LAA/posterolateral ridge. Other targets included the right inferior ganglionted plexus in 36.2% (n=47) and anterior mitral line (AML) in 3.8% (n=5). In 13.1% (n=17) epicardial lesions could not be completed due to difficult anatomy. At the end of the procedure, an attempt to clip the LAA was done in all patients, resulting in 97.7% success (3 LAA clip failures due to anatomical reasons). Acute endocardial mapping revealed a PV reconnection rate of 4.6% (n=24), left superior and right superior PVs being the veins most commonly reconnected (6.15% and 5.38%, respectively). PW and AML reconnections were documented in 8.5 % and 60% (3 out of 5 patients). Multivariate analysis showed left atrial (LA) volume and male gender as predictors for acute endocardial gaps after complete epicardial lesions. A redo procedure after first recurrence was performed in 24.6% (n=32), showing lesion durability of 100% for left PVs, 90.6% for right superior and 93.7% for right inferior PVs. PW remained isolated in 78.1% of patients. Age was a predictive factor for chronic gaps after recurrence. At a mean follow-up of 51±35 months, arrhythmia-free survival after multiple procedures was 68.5%. Conclusion In a large cohort of AF patients undergoing hybrid ablation,acute and chronic lesion durability was hight.LA volume and male gender were predictors of acute reconnection after epicardial ablation.

A multicenter evaluation of repeat ablation for atrial fibrillation in patients with isolated pulmonary veins: a Netherlands Heart Registration study

Abstract Background Of the 25-50% atrial fibrillation (AF) ablation patients who undergo repeat ablation, approximately 15-30% have all pulmonary veins (PVs) isolated at the repeat procedure. Currently, there is limited evidence and a lack of consensus on the appropriate treatment strategy for patients with isolated PVs. Purpose Our aim was to characterize and compare the effectiveness of repeat AF ablation strategies to reduce AF recurrences in patients with isolated PVs using a real-world multicenter registry. Methods All AF patients referred for repeat AF ablation with all PVs isolated at 8 hospitals in the Netherlands were included (Netherlands Heart Registration; 2016-2019). Medical record reviews were conducted for all patients referred for repeat AF ablation to determine study eligibility, the presence of PV reconnection, ablation strategy used, and the outcome of AF recurrence. Patients referred for repeat AF ablation, with PVI only conducted during previous ablations, and all PVs isolated were eligible. Effectiveness of repeat AF ablation strategies were assessed with multivariable Cox models comparing individual ablation strategies, number of ablation strategies performed, and presence of persistent AF. Results Of 2,311 repeat AF ablations performed, 274 (11.9%) were eligible and had all PVs isolated (Figure 1). Patients with isolated PVs were a median age of 66 (IQR 58-70) years, 44.2% were women, 45.6% had persistent or long-standing persistent AF, and the median CHA2DS2-Vasc score was 2 (IQR 1-3). Ablation was not performed in 33 (12.0%) patients with isolated PVs (Figure 2a). A single ablation strategy was performed most often (41.2%; Figure 2a). Posterior box ablation was the most frequent (58.4%) ablation strategy performed, followed by antralization of the PVs (26.3%). Over a median follow-up of 2.0 (1.0-3.3) years, 147 (59.8%) patients with isolated PVs had an AF recurrence >3 months after repeat ablation and 30 (12.7%) patients had another repeat AF ablation within 1 year of repeat procedure. After multivariable adjustment, no difference in AF recurrences was detected between ablation strategies [p>0.05 for all; Figure 2b]. Further, there was no difference detected in AF recurrences for the number of ablation strategies performed (Figure 2c), the individual ablation strategy conducted, and persistent AF (p>0.05 for all). Among patients with isolated PVs, patients with larger left atrial size had a higher risk of AF recurrences [adjusted HR 1.03 (95% CI 1.01-1.05)]. Conclusion Among the 2,311 repeat AF ablations performed, 11.9% had all PVs isolated. Despite multiple ablation strategies performed for isolated PVs, 59.8% of patients had an AF recurrence over follow-up and no difference in the incidence of AF recurrences was detected between repeat ablation strategies. Further evidence is warranted to determine an effective treatment strategy to reduce AF recurrences in AF patients with isolated PVs.

Pulsed-field vs. cryo-balloon based pulmonary vein isolation: does reduced autonomic modulation effect freedom of atrial fibrillation?

Abstract Background Pulsed-field ablation (PFA) is a new energy source integrated into single-shot devices enabling pulmonary vein isolation (PVI) during atrial fibrillation (AF) ablation. It has been demonstrated that PFA is noninferior to conventional thermal ablation. Conceptually, PFA preferentially damages cardiomyocytes and our prior data show that PFA causes less damage to neuronal tissue and reduced autonomic dysfunction than CBA. Here, we analyzed heart rate variability (HRV) as an additional parameter of intracardiac nervous system and whether the damage to neuronal tissue quantified by biomarker release and functional parameters might influence the recurrence rate of atrial fibrillation in PFA and CBA treated patients. Methods We prospectively included consecutive patients with paroxysmal AF undergoing index PVI applying PFA (n=65) or CBA (n=112). We quantified the ablation-dependent effect on intracardiac autonomic nervous system by comparing resting heart rate (HR), HRV and circulating concentrations of the neuronal biomarker S100B. Recurrent AF was detected using Holter ECGs, wearables and telephone interviews. Results Baseline characteristics did not differ between PFA and CBA (age 66 vs. 68 years, female 33% vs. 39%, CHADS-VASc Score 2.1 vs. 2.2, indexed LA volume 32 vs. 31 ml/m², BMI 27.3 vs. 27.4 kg/m²). After CBA-based PVI, HR increased (pre 63 vs. post 70 bpm, p<0.001) and HRV decreased (SDNN pre 54 vs. post 26 ms, p=0.007). After PFA-based PVI, HR and HRV remained stable (HR pre 63 vs. 64 bpm, p=0.591; HRV SDNN pre 37 vs. post 36 ms, p=0.890). In a direct comparison, the HR-increase and HRV-decrease observed after CBA-based PVI was significant compared to PFA (0.8 vs. 7.3 bpm, p<0.001 and SDNN -1 vs. 29 ms, p=0.003). We reported previously that PFA induced less S100B release (28 ng/dl) than CBA (68 ng/dl, p<0.001) and that PV reconnection rates in ReDo procedure were similar between PFA (40%) and CBA (40%). 1 year follow-up revealed freedom of AF in 79% after PFA and 73% after CBA (p=0.230). Dividing patients in upper and lower half of HR increase and S100B release after PVI, patients showed no difference in recurrence rates after CBA. Conclusion These data suggest that neurocardiac damage near the pulmonary veins seems not to contribute to freedom of AF recurrences after PVI.

Radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique: 9-year outcome

Abstract Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns after procedures performed with the first or second generation cryoballoon). Methods Two hundred and twenty patients (paroxysmal AF: 140 patients, persistent AF: 80 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique (First generation: 110 patients (group A); second generation: 110 patients (group B)). The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy (three-dimensional mapping system) depending on the intra-procedural findings. Results During the redo procedure, a mean number of 1.6 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.2 re-conducting PVs, group B: 1.0 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 97 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 13 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in nearly all patients (109/110) because there was only a minor reconnection of 1-2 PVs. All recovered PVs could be isolated sucessfully again. At 108-month follow-up, 69.1 % of all patients were free from an arrhythmia recurrence (152/220 patients; group A: 72/110 patients (65.5 %), group B: 80/110 patients (72.3 %)). There were no major complications in both groups. Conclusions In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).

The contribution of pulmonary veins to the mechanism of persistent AF is dependent on their extent of electrical connection

Abstract Introduction Success rate of pulmonary vein isolation (PVI) is lower in patients with persistent AF (peAF) compared to paroxysmal AF. The indiscriminate use of adjunctive catheter ablation (CA) strategies beyond PVI involve potential risks and new areas of iatrogenic arrhythmogenesis. Thus, distinguishing patients with peAF who may be cured with PVI-only from those who need CA beyond PVI would allow a more efficient patient-tailored CA strategy. Purpose We aimed to evaluate whether the circumferential extent of PV electrical connection assessed during pre-ablation mapping predicts the success rate of a PVI-only CA strategy. Methods Consecutive patients with peAF undergoing first CA consisting of a PVI-only CA were included. The extent of PV electrical connection was assessed using a circular mapping catheter placed within the PVs prior to ablation. Based on their follow-up (FU), patients were considered: a) PVI-responders, in the absence of AF or atrial flutter recurrence ≥ 12 months off-anti-arrhythmic drugs, b) PVI-non responders, in case of AF recurrence despite absence of any PV reconnection at reintervention, or despite one reintervention consisting of stand-alone residual PV connection ablation, c) PVI response was considered as indeterminate for all other instances (eg. Sinus rhythm maintenance on-AAD, shorter FU, etc). Results 148 patients were included (mean age 64 ± 9.7 years, mean peAF duration 7.3 ± 7 months). After a mean FU of 18 months after last PVI, we identified 60 PVI-responders and 25 PVI- non responders. In the remaining 63 patients, PVI response was indeterminate. In PVI-responders, the median percentage of the PV circumference displaying PVs potentials was significantly higher compared to PVI-non responders (68% vs. 60%, respectively; p=0.035). Conclusions The circumferential extent of PVs connection is correlated to the success rate of a stand-alone PVI CA strategy in patients with peAF. It may be a marker of the contribution of PVs to AF. Patients with poorly connected PVs during index CA ablation may warrant additional ablation strategies beyond PVI.

Comparison of pulsed field ablation and thermal ablation for repeat procedures after failed prior thermal ablation for atrial fibrillation

Abstract Background Procedural efficiency and long-term clinical outcome after a first pulmonary vein isolation (PVI) for atrial fibrillation (AF) with pulsed-field ablation (PFA) has recently been reported to be non-inferior compared to radiofrequency ablation (RFA) and cryoballoon ablation (CBA). Studies comparing PFA and RFA for a first redo procedure in patients with failed prior thermal PVI are lacking. Purpose We sought to compare procedural efficiency and 1-year success rate (i.e maintenance of sinus rhythm) between PFA and RFA in patients undergoing a first redo procedure due to recurrence of atrial tachyarrhythmias after a prior thermal PVI. Methods Patients with recurrences after a 90-day blanking period following an index PVI with either RFA or CBA referred for a first redo ablation were enrolled. All redo procedures were done using a 3D electro-anatomical mapping to identify PV reconnections and guide repeat PVI by either PFA or RFA. In cases of incomplete or ostial isolation, the PFA group was treated using the standard 8-applications per vein while the CLOSE protocol was used for segmental PVI completion in the RFA group. Extra-PV lesion sets were added at the discretion of the treating physician. Patients were followed with 7d-Holter ECGs 3, 6, and 12 months after reablation. Recurring arrhythmias were categorized as persistent AF, paroxysmal AF, or atrial flutter. Secondary endpoints were periprocedural complications, total ablation time, radiation time and exposure. Results A total of 220 patients (median age 67 [IQR 58-74] years, 64% male, 64% persistent AF) were enrolled and equally treated with PFA or RFA (110 in both groups). There were no statistically significant differences in the clinical characteristics at baseline. Procedure time was shorter in the PFA group (95 vs. 122 minutes, p=0.001) whereas radiation time and dose were higher in the PFA group (17.0 vs. 6.4 minutes, p=<0.001 and 4.9 vs. 2.2 Gycm2, p=<0.001). Additional posterior wall ablation (PFA) or roof line (RFA) was performed predominantly in the PFA group (61 patients, 55.5 %) and in 5 patients (4.5 %) in the RFA group (p=0.001). Major complications occurred in 3 patients in the PFA group and in 1 patient in the RFA group (see Picture 2). Freedom from arrhythmia in Kaplan-Meier analysis 12 months after the reablation was 61% (CI 50-74%) in the PFA group and 59% (CI 49-71%; log-rank test p=0.81). No differences in outcomes were observed in the pooled group between paroxysmal AF (60%, CI: 50-72%) and persistent AF (61%, CI: 51-73%, p=0.64). Recurrence of organized atrial tachycardia was more common in the PFA group (p=0.018) Conclusion In patients undergoing a first redo procedure after a first round of thermal PVI and with recurrence of atrial tachyarrhythmia, PFA for reablation resulted in shorter procedure times compared to RFA despite more frequent posterior wall ablation. Long-term arrhythmia-free survival after the redo procedure was similar in both groups.Kaplan-Meier analysis of redo proceduresProcedure and outcome data

Characterization of conduction recovery and atrial electrophysiological properties after pulmonary vein isolation using pulsed field ablation

Abstract Background Pulsed field ablation (PFA) is a relatively new technology for isolation of pulmonary veins in patients with atrial fibrillation (AF). Data addressing reasons for recurrent atrial fibrillation despite primarily successful pulmonary vein isolation (PVI) using PFA are scarce, due to an up to date limited number of patients treated this way. Objective The aim of this study was to analyze electrophysiological characteristics of reconduction and / or left atrial substrate of patients referred to our center for Re-Do procedures for recurrent AF after an initial PVI using PFA. Methods 90 patients (mean age 66±9 years, 69 male (77%)) had been treated in our center from November 2021 to July 2023 with PVI using PFA. 9 (10%) of these patients were referred for Re-Do procedures. These were performed by radiofrequency ablation (RFA) using Carto system including high density mapping and high power / short duration (HPSD) ablation. We analyzed location of PV reconnection and low voltage areas (LVA) in the left atria. Results 7 out of 9 patients (77%) presented with reconnections of pulmonary veins. In one patient a single vein showed reconduction (RSPV), in 5 patients 2 veins were conducting (1x LSPV, 3x LIPV, 1 left sided common os (LCo), 1x RSPV, 3x RIPV). None of the patients showed 3 or 4 reconnected veins. Areas of reconduction in each vein were: LSPV 1x ridge, 1x posterior; LIPV 1x posterior, 1x anterior and posterior; LCo 1x posterior, RSPV 1x anterior, 2x carina, 1x anterior and posterior; RIPV 1x complete, 2x carina. In 7 patients a fibrotic atrial cardiomyopathy (FACM) was diagnosed via high density mapping of LVA’s. In 2 of these patients all 4 pulmonary veins were chronically isolated after the initial PVI. All patients except one (very small anterior LVA) with FACM ≥1 were treated with additional linear or encircling lesions according to the individual extent of the fibrotic areas. 2 patients had no LVA’s detectable. In one of those 2 patients 2 veins had reconnected. The other patient had chronically isolated veins (no proof of dormant conduction with adenosine) and no detectable non-PV-triggers under isoprenaline. Conclusion In the population of patients undergoing PVI using PFA in our center, only 10% had clinically relevant recurrences leading to the necessity of a Re-Do procedure. Most patients (77%) in this setting had reconnections of pulmonary veins. There is a tendency of posterior reconnections of the left pulmonary veins and reconnections of the carina of the right pulmonary veins, but the number of patients is too small to clearly define predilection sites that have to be paid attention to when using PFA. Additionally, left atrial substrate is an important problem in patients with recurrent AF despite primarily successful PVI and has to be considered and thoroughly addressed in Re-Do procedures.Reconnection of LSPV and anterior LVAAblation of RSPV and LSPV (posterior)

Electrophysiological characteristics and durability of index pulsed field ablation lesions from redo procedures for atrial arrhythmia recurrences

Abstract Background Catheter ablation for atrial fibrillation (AF) has been performed using mainly thermal energy sources (radiofrequency, cryo, or laser). Pulsed field ablation (PFA) is a novel energy with interesting safety and effectiveness demonstrated in previous preclinical and clinical trials. Purpose We sought to assess the electrophysiological characteristics and durability of PFA index procedure procedures using a pentaspline PFA catheter as assessed based on redo procedures in patients with AT/AF recurrences. Methods A total of 169 patients (paroxysmal AF (PAF), 120; persistent AF (PsAF), 49) who underwent PFA using a pentaspline PFA catheter in the index procedure from November 2021 to July 2023 were studied. Pulmonary vein isolation (PVI) was performed with PFA in all patients with additional PFA lines: i)posterolateral mitral isthmus (MI) ablation in 25, ii) posterior line in 40 patients. Twenty-seven patients (PAF, 11; PsAF, 16) had atrial arrhythmia (atrial tachycardia (AT) or AF) recurrence after a 3-month blanking period (16%). We analyzed the electrophysiological characteristics of previous PFA lesions in 18 (PAF, 8; PsAF, 10) out of 27 patients in whom an activation and voltage mapping using 3-D electroanatomical mapping system was available. Results PV reconnections were identified in 7 of 18 patients (13PVs/69PVs ,18.8%) at the PV-LA junctions and carina regions of both left PVs and right PVs, mainly at the anterior aspect of right PV carina (n=6). In 6 out of 10 redo cases, posterolateral MI line using PFA was performed in the index procedure based on our strategy for PsAF ablation. In these 6 cases with previous MI line using PFA for PsAF ablation endocardial PFA was combined with marshall vein ethanolization(Et-VOM). Additional RF endocardial ablation and in the CS was needed to achieve MI block in 2 (33%) in the index procedure. 3D mapping of redo cases showed MI line gaps in 6/6 (100%). In 3 of those patients, the clinical arrhythmia recurrence was a perimitral AT (50%). Nine of the 10 PsAF patients who underwent a redo procedure had an index procedure complete posterior line. Remapping demonstrated durable block in 7/9 (78%). One of these patients presented with a roof dependent AT diagnosed in the redo procedure. Durable posterior lines received a significantly larger number of PFA deliveries during the index procedure: 16.4±3.3 vs 10.0±2.8 respectively, p=0.041). Conclusion This study based on redo cases after PFA using a pentaspline PFA catheter shows that PFA is associated with high durability for PVI and posterior line ablation. However the durability of MI line are poor, even when combined with VOM ethanolization. Further research is needed to define the optimal number of deliveries required to achieve durable posterior line block.

Extended period rhythm outcomes of posterior box isolation of left atrium during pan-spectrum of atrial fibrillation catheter ablation in 4 randomized clinical trials

Abstract Background Catheter-based electrical posterior box isolation (POBI) in addition to circumferential pulmonary vein isolation (CPVI) did not improve rhythm outcome of atrial fibrillation (AF) catheter ablations (AFCA). We analyzed the long-term rhythm outcomes of previously conducted our 4 randomized controlled trials (RCTs) comparing CPVI vs. additional POBI by intention to treat. Methods We analyzed 575 AF patients who were included in 4 RCTs (PAF [paroxysmal AF], PEACEFUL [persistent to paroxysmal AF]; POBI [persistent and long-standing persistent AF]; and RILI [repeat procedures] trials) comparing the usefulness of additional POBI after further long-term protocol-based rhythm follow-up. We compared the primary endpoint as clinical recurrence after index procedure and major adverse cardiac event, and the secondary endpoint as procedure time, procedure-related complication rate, recurrence as atrial tachycardia (AT), and cardioversion or repeat procedure rates. We also conducted Cox regression analysis to evaluate the efficacy of POBI. Results After a median follow-up of 48months, there was no significant difference in the clinical recurrence (42.9% vs. 41.3%; log-rank P=0.855) and major adverse cardiac event (4.5% vs. 3.7%; log-rank P=0.675). Procedure time was significantly longer (p=0.003) and AT recurrence rate was higher (6.6% vs. 12.6%; log-rank P=0.014) in the additional POBI group. In patients who experienced clinical recurrence, there were no significant differences in the rates of cardioversion (33.9% vs. 46.6%, P=0.059) or the need for a repeat procedure (30.4% vs. 31.7%, P=0.955) between the two groups. Catheter-based POBI did not improve AFCA outcomes (HR 1.07 [0.81~1.40], P=0.655), regardless of paroxysmal, persistent to paroxysmal, persistent AFs, or the 2nd procedures. In the redo mapping after RCTs (n=64), PV reconnection rate did not differ, but reentrant AT was more common in POBI than in CPVI alone group (46.7% vs. 10.7%, P=0.007), while extra-PV trigger was more common in CPVI alone than in POBI group (29% vs. 3.0%, P=0.012). Conclusions Additional-POBI to CPVI did not improve long-term rhythm outcomes. Additional-POBI to CPVI is related to the increase of AT recurrence and the decrease of extra-PV trigger.

Comparing cryoballoon and contact-force guided radiofrequency ablation in pulmonary vein isolation for atrial fibrillation in patients with hypertrophic cardiomyopathy.

Pulmonary vein isolation (PVI) employing cryoballoon (CB) or contact force-guided radiofrequency (CF-RF) catheter ablation has been established as an effective strategy for managing atrial fibrillation (AF). However, its efficacy in hypertrophic cardiomyopathy (HCM) remains to be further explored. This retrospective study analyzed 60 consecutive AF patients with HCM (average age 67 ± 10 years; 41 men) who were consecutively admitted to our hospital from January 2014 to December 2022 and underwent initial PVI. The patients were treated with CB (26 patients) or CF-RF (34 patients). Successful PVI was achieved in both groups without significant complications. In the CF-RF group, additional ablations were performed on the cavotricuspid isthmus (14.7% of patients) and the anterior line (2.9%). The CB group benefited from reduced procedural times (93 ± 31 vs. 165 ± 60min, p < 0.05) and decreased saline irrigation requirements (77.5 ± 31.4 vs. 870 ± 281.9 mL, p < 0.0001). Using a contrast medium was exclusive to the CB group (33.8 ± 4.2 mL). In a 12-month follow-up, the atrial tachyarrhythmia recurrence-free rates in the CB and CF-RF groups were comparable (77% and 76%, respectively; p = 0.63 according to the log-rank test). Notably, pulmonary vein reconnection was prevalent in most (7 out of 8) patients requiring a secondary ablation procedure. PVI is feasible as a strategy for AF in patients with HCM employing either CB or CF-RF techniques. While the recurrence-free rates were comparable in both groups, differences were noted in procedure duration, saline usage, and the need for a contrast medium.

Pulsed Field Ablation of Atrial Fibrillation: Concept, Evidence and Available Technologies Where do we stand in 2024?

Catheter ablation (CA) has been commonly used in treatment of symptomatic patients with Atrial Fibrillation (AF) with Pulmonary vein isolation (PVI) being considered as the cornerstone of AF ablation procedure (1). However, there are major challenges facing PVI using current CA technologies including the durability of PVI, risk of Pulmonary veins (PV) reconnection, collateral damage especially phrenic nerve injury and oesopahguial injury (2). Therefore, better technology was needed to improve efficacy and safety. Pulsed field ablation (PFA) has emerged over last few years as new ablation modality for the treatment of AF using non-thermal energy and irreversible electroporation. This review provides an update on concept, current evidence, gap in evidence and available technology for PFA of AF.

Impact of inter-lesion distance and first-pass isolation on outcomes of pulmonary venous isolation for paroxysmal atrial fibrillation.

Contiguity of ablation lesions is a critical determinant of success for paroxysmal atrial fibrillation (PAF) ablation. Evidence supports maintaining an inter-lesional distance (ILD) ≤ 6mm during pulmonary venous isolation (PVI). Meanwhile, first-pass isolation (FPI) on PVI outcome in follow-up was not deeply studied. The impact of ILD and FPI on PAF ablation outcomes was investigated. Consecutive PAF patients who underwent first-time antral PVI were recruited. Coordinates of ablation points were extracted from the electro-anatomical mapping system and analyzed using custom-developed software to determine the ILD. A gap is defined as ILD greater than 6mm. FPI was defined as the achievement of PVI by encircling the ipsilateral veins while simultaneously recording their electrical activity using a multipolar catheter. The primary endpoint was freedom from documented atrial arrhythmias including AF, atrial tachycardia (AT), or atrial flutter (AFL) lasting longer than 30s during follow-up. A total of 105 patients underwent first-time antral PVI. During 13.3 ± 0.6months of follow-up, atrial arrhythmias recurrence was noted in 22.9% of the patients. Atrial arrhythmia recurrence was significantly higher in patients with more gaps (> 2) (37.0% versus 11.9%, P < 0.01), and the number of gaps was an independent predictor of AF/AT/AFL recurrence. (Hazard ratio [HR] 1.20, 95% CI 1.03-1.40, P = 0.02). The group with FPI for at least one ipsilateral pair of PVs exhibited a decreased number of gaps (2.0 versus 7.0, P < 0.01) and demonstrated a significant correlation with a reduction of recurrence (HR 0.26, 95% CI 0.09-0.71, P = 0.01). Among 16 patients who underwent repeat ablation, the number of gaps during the index PVI was associated with PV reconnection (PVR) (P < 0.01). Gaps created during PVI are a modifiable determinant of AF/AT/AFL recurrence, and avoidance of gaps is crucial to improve clinical outcomes of PAF ablation. In addition, FPI exhibited a strong predictive capability for clinical success in patients with PAF.