Initial Pulmonary Vein Isolation Research Articles

Adherence to CLOSE protocol, high-power and low baseline generator impedance predicts durable pulmonary vein isolation

Abstract Background Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is predominantly attributed to pulmonary vein reconnection (PVR). Predictors of AF recurrence were widely studied. However, data are scarce on the procedural parameters that predict chronic PVR. Aims to study the PVR rates and the predictors of PVR after initial PVI procedure. Methods We included 100 consecutive patients who underwent repeated ablation due to AF recurrence after initial PVI with the CARTO system, both procedures performed between 2018 and 2023. Results The mean age of the patients was 60 ± 12 years, 36% were female, and 44% had persistent AF. Thirty-eight patients underwent initial CLOSE-guided, and sixty-two underwent initial non-CLOSE PVI. Repeat procedure was performed 21 ± 14 months after the initial procedure. In total, PVR was found in 192 of 373 PVs (51.5%) and all PVs were isolated in 17/100 (17%) patients. Factors associated with all PVs being isolated were adherence to the CLOSE protocol (39.5% vs. 3.5%, p < 0.0001), higher delivered mean power (37.5W vs 30W, p = 0.027), presence of first-pass isolation (88.2% vs 40.4%, p = 0.0007), and lower baseline generator impedance (127.6 vs 136.6 Ω, p = 0.0027; respectively). Baseline generator impedance >130 Ω (AUC = 0.7403, sensitivity: 77.1%, specificity: 68.8%, p = 0.0032) was associated with significantly higher probability of PVR (OR = 6.757; p < 0.0001). Conclusions Our findings indicate that adherence to the CLOSE protocol, higher power setting, first-pass isolation, and baseline generator impedance <130 Ω during AF ablation improves the durability of PVI and reduces the incidence of PVR.

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)

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.

The role of high density mapping in cathether ablation of paroxysmal atrial fibrillation - preliminary results

Abstract Introduction Despite technical progress and numerous approaches in ablation strategies, long-term success in paroxysmal atrial fibrillation (PAF) treatment is still suboptimal. Non-transmural ablation lesions in antral isolation lines, causing late electrical reconnection between pulmonary veins (PVs) and left atrium (LA) could present one of the potenital issues for reduced effectiveness of radiofrequency cathether ablation (RFCA). Potentially, these lesions can be identified with high-density (HD) mapping as low voltage, fragmented electrocardiograms (LFEGMs) representing gaps in antral isolation lines. Purpose To compare the long-term pulmonary vein isolation (PVI) durability of two PVI verification methods (circumferential vs high-density mapping catheter) after catheter ablation of PAF. Methods Thirty-three patients with PAF were prospectively randomized to PVI verification by either circumferential mapping catheter (CM group) or HD mapping catheter (HD group). Patients in both groups underwent PVI according to the CLOSE protocol with PVI verification after a 30 minute waiting period. Additionally, in the HD group antral ablation lines were mapped to search for LFEGMs that were defined as fragmented signals (at least 3 deflections) and/or conduction to the LA during stimulation on the ablation line (10 mA at 1 msec) and/or voltage amplitude above 0.1 mV. If LFEGMs were found, additional ablations were performed until electrical inactivity was confirmed with the HD catheter. To monitor AF reccurence 6-day continuous holter ECG was performed after 3, 6, and 12 months after the initial procedure. Arrhythmia recurrence was defined as any atrial tachyarrhythmia lasting more than 30 seconds. Patients also underwent a mandatory second procedure 12 months after the initial PVI, during which HD re-mapping was performed to test durability of PVI and absence of conducting gaps in antral isolation lines. Results There were 16 patients in the CM group and 17 patients in the HD group. Baseline characteristics (gender, age, body mass index, LA volume index, left ventricular ejection fraction, CHA2DS2VASc score) did not significantly differ between the groups. Procedural characteristic are summarized in Table 1. There were significantly more isolated PVs at the remapping procedure in the HD group compared to the CM group (91.2% (62/68) vs 75.0% (48/64); P=0.021). There were also significantly more patients with all PVs durably isolated in the HD group (82.4% (14/17) vs 37.5% (6/16); P=0.008). However, arrhythmia recurrence rate was similiar between the CM and HD group (43.8% (7/16) vs 35.3% (6/17); P=0.640). Conclusion HD mapping improved PVI durability after 12 months compared to standard CM verification. However, lower number of isolated PVs in the HD group did not have an impact on arrhythmia reccurence.

Comparative analysis of clinical outcomes in repeat ablation for recurrent atrial tachyarrhythmia following initial pulmonary vein isolation with pulsed-field ablation and cryoballoon ablation

Abstract Background While pulsed-field ablation (PFA) holds promise for the initial catheter ablation performing pulmonary vein (PV) isolation (PVI) in patients with atrial fibrillation (AF), a repeat procedure remains necessary for those experiencing recurrent atrial tachyarrhythmia (ATA). This study aimed to evaluate the clinical outcomes of repeat procedures following the initial PFA in patients with recurrent ATA by comparing that following the initial CBA. Methods Patients who underwent a second ablation for recurrent ATA following initial PVI with pentaspline PFA or cryoballoon ablation (CBA) were included. Repeat ablation utilized radiofrequency current ablation with three-dimensional mapping guidance, involving repeat PVI combined with linear ablations when necessary. Acute data, such as documented arrhythmia before the repeat procedure, the number of reconnected PVs, procedural characteristics, and clinical follow-up, were analyzed. Results In total, 110 patients underwent initially successful PVI with PFA (N = 51) and CBA (N = 59), followed by a repeat procedure for recurrent ATA with a mean time interval of 365±299 days between the two procedures. The primary indication at the repeat procedure was atrial tachycardia (AT) in the PFA group (N = 27, 53%) and AF in the CBA group (N = 47, 80%). The overall PV reconnection rate per vein was 22.1%, with no significant difference between the two groups (19.1% in PFA vs. 24.7% in CBA, P = 0.16). Repeat PVI was successfully performed in all patients with PV reconnection (41.2% in PFA vs. 55.9% in CBA, P = 0.12). PV reconnection was most commonly found at the right inferior PV in both groups (25.5% vs. CBA; 32.2%, P = 0.44). Additional substrate modification was conducted in 76.5% of the PFA group and 74.6% in the CBA group, respectively (P = 0.82). The mean follow-up period was 349±280 days. The Kaplan-Meier curve indicated no statistical significance in the 1-year arrhythmia-free survival after the repeat procedure (62.4% in PFA vs. and 73.0% in CBA group, P = 0.54, Figure). Conclusion Comparable lesion durability between the initial PVI with PFA and CBA was unveiled during the repeat ablation. The second ablation for recurrent arrhythmia following initial PFA demonstrated a favorable clinical success rate at one year after the subsequent procedure, showing no significant difference compared to repeat ablation subsequent to CBA.arrhythmia-free survival after the repe

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.

Rates of pulmonary vein reconnection at repeat ablation for recurrent atrial fibrillation and its impact on outcomes among females and males.

Several studies have demonstrated that females have a higher risk of arrhythmia recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF). There are limited data on sex-based differences in PV reconnection rates at repeat ablation. We aimed to investigate sex-based differences in electrophysiological findings and atrial arrhythmia recurrence after repeat AF ablation METHODS: We conducted a retrospective study of 161 consecutive patients (32% female, age 65±10 years) who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Demographics, procedural characteristics and follow-up data were collected. Recurrent atrial tachycardia (AT)/AF was defined as any atrial arrhythmia ≥30 s in duration. Compared to males, females tended to be older and had a significantly higher prevalence of prior valve surgery (10vs. 2%; P=.03). At repeat ablation, PV reconnection was found in 119 (74%) patients. Males were more likely to have PV reconnection at repeat ablation compared to females (81vs. 59%; P=.004). Excluding repeat PV isolation, there were no significant differences in adjunctive ablation strategies performed at repeat ablation between females and males. During follow-up, there were no significant differences in freedom from AT/AF recurrence between females and males after repeat ablation (63vs. 59% at 2 years, respectively; P=.48). After initial PV isolation, significantly fewer females have evidence of PV reconnection at the time of repeat ablation for recurrent AF. Despite this difference, long-term freedom from AT/AF was similar between females and males after repeat ablation.

Adherence to the CLOSE Protocol and Low Baseline Generator Impedance Are Independent Predictors of Durable Pulmonary Vein Isolation.

Background: Atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) is predominantly attributed to pulmonary vein reconnection (PVR). Predictors of AF recurrence have been widely studied; however, data are scarce on procedural parameters that predict chronic PVR. We aimed to study PVR rates and predictors of PVR. Methods: We retrospectively included 100 patients who underwent repeated ablation due to AF recurrence after initial PVI with the CARTO system. PVR was determined during the repeated procedure by electrophysiological evaluation, and initial procedural characteristics predicting PVR were studied, including adherence to the CLOSE protocol, use of high power, first-pass isolation (FPI), and baseline generator impedance (BGI). Results: Thirty-eight patients underwent initial CLOSE-guided PVI, and sixty-two underwent initial non-CLOSE PVI. A repeat procedure was performed 23 ± 16 months after the initial procedure. In total, PVR was found in 192 of 373 PVs (51.5%), and all PVs were isolated in 17/100 (17%) patients. Factors associated with all PVs being isolated were adherence to the CLOSE protocol, a higher power setting, the presence of bilateral FPI, and lower BGI (88% vs. 28%, p < 0.0001; 37.5 W vs. 30 W, p = 0.0276; 88.2% vs. 40.4%, p = 0.0007; and 127.6 Ω vs. 136.6 Ω, p = 0.0027, respectively). In initial procedures with adherence to the CLOSE protocol, the FPI rate was significantly higher (73.7% vs. 25%, p < 0.0001), while there were no significant differences in terms of procedure time and left atrial dwell time (81 vs. 85 min, p = 0.83; and 60 vs. 58 min, p = 0.08, respectively). BGI ≥ 130 Ω (AUC = 0.7403, sensitivity: 77.1%, specificity: 68.8%, p = 0.0032) was associated with a significantly higher probability of PVR (OR = 6.757; p < 0.0001). In multivariable analysis, independent predictors for PVR were non-adherence to the CLOSE protocol and BGI ≥ 130 Ω. Conclusions: Our findings indicate that adherence to the CLOSE protocol and baseline generator impedance < 130 Ω during AF ablation are independent predictors of PVI durability.

Conduction velocity mapping in atrial fibrillation using omnipolar technology.

Recent studies have shown that atrial slow conduction velocity (CV) is associated with the perpetuation of atrial fibrillation (AF). However, the criteria of CV measurement have not been standardized. The aim of this study was to evaluate the relationship between the slow CV area (SCVA) measured by novel omnipolar technology (OT) and AF recurrence. This study included 90 patients with AF who underwent initial pulmonary vein isolation (PVI). The segmented surface area of the SCVA was measured by left atrial (LA) electrophysiological mapping using OT before the PVI. The proportion of the SCVA at each cutoff value of CV (from<0.6to<0.9m/s) was compared between the patients with and without AF recurrence. During a mean follow-up period of 516±197 days, the recurrence of AF after the initial PVI was observed in 23 (25.5%) patients. In patients with AF recurrence, the proportion of the SCVA in the LA posterior, LA appendage (LAA), and LA anterior were significantly higher than those without AF recurrence. The multivariate analysis indicated that the proportion of the low voltage area and the SCVA in the LA anterior (local CV<0.7m/s) were independent predictors of AF recurrence (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14; p=0.03; HR, 1.40; 95% CI, 1.07-1.83; p=0.01, respectively). By evaluating the local CV using OT, it was indicated that SCVA with CV<0.7m/s in the LA anterior is strongly associated with AF recurrence after PVI.

Recurrent Atrial Fibrillation Ablation after Initial Successful Pulmonary Vein Isolation.

Pulmonary vein isolation (PVI) is an effective treatment option for patients with symptomatic atrial fibrillation (AF). However, the electrical recovery of pulmonary veins (PVs) is the main trigger for AF recurrences. This study investigates the characteristics of patients admitted for redo AF ablation, the PV reconnection rates depending on previous ablation modalities and the impact of different ablation strategies for redo procedures. Consecutive patients undergoing first redo AF ablation were included. Patients were grouped according to the electrical recovery of at least one PV. The impacts of the technique for first AF ablation on PV reconnection rates and patients with and without PV reconnection were compared. Different ablation strategies for redo procedures were compared and its recurrence rates after a mean follow-up of 25 ± 20 months were investigated. A total of 389 patients (68 ± 10 years; 57% male; 39% paroxysmal AF) underwent a first redo. The median time between the first and redo procedure was 40 ± 39 months. Radiofrequency was used in 278 patients, cryoballoon was used in 85 patients and surgical AF ablation was performed on 26 patients. In total, 325 patients (84%) had at least one PV reconnected, and the mean number of reconnected PVs was 2.0 ± 1.3, with significant differences between ablation approaches (p for all = 0.002); this was mainly due to differences in the left inferior PV and right superior PV reconnections. The presence of PV reconnection during redo was not associated with better long-term success compared to completely isolated PVs (67% vs. 67%; log-rank p = 0.997). Overall, the different ablation strategies for redos were comparable regarding AF recurrences during follow-up (p = 0.079), with the ablation approach having no impact in the case of left atrial low voltage or without. PV reconnections after initial successful PVI are common among all techniques of AF ablation. Long-term rhythm control off antiarrhythmic drugs was possible in 2/3 of all patients after the redo procedure; however, different ablation strategies with extra-PV trigger ablation did not improve long-term success. Patients with recurrent AF after PVI constitute a challenging group of patients.

Abstract 18656: Characterization of Pulmonary Vein Reconnection in Repeat Procedures After After Initial Cryoballoon Ablation Identified With High Density Mapping

Introduction: Catheter ablation of atrial fibrillation using the cryoballoon has become an alternate strategy to radiofrequency for pulmonary vein isolation (PVI). Both techniques, however, can result in pulmonary vein reconnection and the need for recurrent ablations. Objective: To study the incidence and specific location of pulmonary vein reconnection in patients with prior cryoballoon ablation for atrial fibrillation Methods: Retrospective analysis of patients that underwent radiofrequency ablation following a single initial cryoballoon PVI ablation was performed. Twenty patients were studied, all of whom underwent repeat ablation using radiofrequency with a mapping system (Rhythmia, Boston Scientific). A gap was defined as entrance conduction from the LA into the PV as suggested by the activation map. Results: Patients had an average of a 20 month period of normal sinus rhythm after initial ablation. A total of 48 gaps were identified in 18/20 patients (2.4 gaps per patient). The most common site of PV-LA conduction reconnection was at the superior pulmonary veins, specifically on the anterior portions. 60% (12/20) of patients had noted reconnection sites at the left superior pulmonary vein. All but one of these patients had gaps on the anterior surface of the vein. 75% (15/20) of patients were identified as having reconnection sites at the right superior pulmonary vein. All of these patients had gaps on the anterior surface of the vein. Less commonly, the left and right inferior veins each had 40% (8/20) patients with reconnection at these areas, with no consistent surface as the main site of reconnection. Further, 85% (17/20) patients had procedural ablation beyond only pulmonary vein re-isolation, owing primarily to the occurrence of atypical atrial flutters or atrial tachycardias that were seen during the repeat procedure itself Conclusion: Cryoballoon ablation is a successful technique for PVI in AF patients. However, reconnection of these sites is possible. Our analysis shows that the most common sites are at the anterior surface of the superior pulmonary veins. This could portend a potential drawback to be cognizant of during these initial procedures. Further analysis with a larger patient population will be necessary

Abstract 14374: The Atrium Conduction Mappings Using Omnipolar Technology for Detecting Epicardial Connection in Patients With Atrial Fibrillation

Background: Epicardial connection (Epi-connection) between the right atrium (RA) and right pulmonary vein (RPV) has been known to complicate pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Meanwhile, the omnipolar voltage detected using EnSite™ Omnipolar Technology (OT) has been reported to facilitate the recognition of wavefront direction and see every signal in 360 degrees. Purpose: We investigated whether epicardial RA-RPV connection can be evaluated with OT mapping before PVI. Methods: We prospectively studied 113 consecutive patients (74 males, age 71±10 years, 68 paroxysmal AF) who underwent initial pulmonary vein isolation (PVI) for AF. The RA-RPV connections before PVI were assessed using OT mappings during right atrial pacing. True Epi-connections were defined as cases that required additional ablation medial to the PV more than 1 cm from the ablation line after the right PVI. Results: RA-RPV connections before PVI were detected in 7 out of 113 patients (6.2%). True Epi-connections were confirmed in 7 out of 113 patients (6.2%, 6 patients with carina and 1 with right superior PV) and were not related to any other clinical data, blood samples, or echocardiographic findings. Only 5 out of 7 patients with RA-RPV connections before PVI showed True Epi-connections (Figure). Conclusion: The prevalence of Epi-connections is not high, however, the conduction mapping using OT could be useful for detecting Epi-connection (especially non-carina Epi-connection) before PVI.

Catheter Ablation Approaches for the Treatment of Arrhythmia Recurrence in Patients with a Durable Pulmonary Vein Isolation

Catheter ablation has emerged as an effective treatment for atrial arrhythmias, and pulmonary vein isolation (PVI) is the cornerstone of ablation strategies. Significant technological evolution and widespread increase in operator experience have facilitated the effectiveness of catheter ablation to achieve durable PVIs in single or multiple ablation procedures. Nevertheless, arrhythmia recurrence is a common problem even after establishing PVI. Data on catheter ablation in these patients are sparse and repeat ablation in this population is highly challenging. In this review we have summarized the available data as well as potential strategies of catheter ablation following the initial PVI.

Regional variations in patient selection and procedural characteristics for cryoballoon ablation of atrial fibrillation in the cryo global registry

BackgroundCryoballoon ablation is a well-established anatomical approach for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Although widely adopted, regional variations in standards of care have not been well characterized.MethodsPatients with AF were enrolled in the Cryo Global Registry (NCT02752737) from May 2016 to Sept 2021 at 128 sites in 37 countries and treated with cryoballoon ablation according to local clinical practice. Baseline patient and procedural characteristics were summarized for 8 regions (Central Asia & Russia, East Asia, Europe, Middle East, North America, South Africa, South America, and Southeast Asia). Serious procedure-related adverse events (SAEs) were evaluated in a subset of patients with ≥ 7 days of follow-up.ResultsA total of 3,680 patients undergoing initial PVI for AF were included. Cryoballoon ablation was commonly performed in patients with paroxysmal AF. Mean age ranged from 47 ± 12 years in the Middle East to 64 ± 11 years in East Asia. Mean procedure time was ≤ 95 min in all regions. Average freeze duration ranged from 153 ± 41 s in Southeast Asia to 230 ± 29 s in Central Asia & Russia. Acute procedural success was ≥ 94.7% in all geographies. In 3,126 subjects with ≥ 7 days of follow-up, 122 procedure-related SAEs were reported in 111 patients (3.6%) and remained low in all regions. One procedure-related death was reported during data collection.ConclusionsDespite regional variations in patient selection and procedural characteristics, PVI using cryoballoon ablation was performed with high acute success and short procedural times around the world.Clinical trial registrationhttps://clinicaltrials.gov/ct2/show/NCT02752737Graphical

Electrophysiological findings during re-do procedures after single-shot pulmonary vein isolation for atrial fibrillation with pulsed field ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) is a novel non-thermal ablation modality which applies electroporation to destabilize the cell membranes, leading to selective ablation of the atrial myocardium whilst sparing surrounding tissues and structures. It’s discriminating nature and potential for minimal adnexal injury opens new, promising horizons into catheter ablation of AF. However, one of the major issues to address is long-term results of the technique. Purpose To investigate the electrophysiological findings and type of arrhythmias during redo-ablation in 15 patients who underwent pulmonary vein isolation (PVI) for atrial fibrillation (AF) using single-shot PFA. Methods We investigated patients who underwent redo-ablation due to occurrence of AF/ atrial flutter (AFL) or tachycardia (AT) following initial PVI with PFA. We report the electrophysiological findings and ablation strategy during redo-ablation. Results Out of 447 patients undergoing index PVI with PFA, 15 patients (age: 61.8±10.4 years; 8 (53%) males; left atrial volume index (n=10): 39.4±14.6 mL/m2) were referred for redo-ablation after index PFA. Indication for the index ablation was paroxysmal-AF in 8 patients, persistent-AF in 6 and long-standing-persistent-AF in one patient. Mean time-to-recurrence was 5.0±1.8months. Three patients received additional posterior-wall-isolation during index PFA. Thirteen (85%) patients suffered AF recurrence and 5/13 had concomitant AFL. In the remaining 2 patients, one had a recurrence of (box-dependent) AFL, and one had AT. No patients had all PVs reconnected. Reconnection in zero, one, two or three PVs was found in 33%, 20%, 20%, and 27% of patients, respectively. All 7 patients with zero or one reconnection with AF recurrence received additional/repeat posterior-wall-isolation during re-ablation, while in the others PVs were re-isolated. In 1/3 patients who had posterior-wall ablation during index PFA, durable isolation of the posterior wall was confirmed during re-do procedure. Patients with only AFL/AT had no reconnection of PVs, and the substrate was successfully ablated. Conclusion We observed durable PVI in 62% of the PVs in patients with AF/AFL recurrence after PFA PVI. In one-third of patients all PVs were isolated. The predominant recurrent arrhythmia following PVI-only was AF. Concomitant (33%) or isolated (14%) AFL/AT recurrence was observed in 47% of patients.

PO-01-097 HYPERLIPIDEMIA AS A PREDICTIVE RISK FACTOR OF ATRIAL ARRYTHMIA RECURRENCE FOLLOWING ABLATION: A DECAAF II SUBSTUDY

Multiple co-morbidities are known risk factors in atrial fibrillation (AF) recurrence following pulmonary vein isolation (PVI). Our aim was to assess the effect of hyperlipidemia (HLD) and statin therapy on atrial arrhythmia (AA) recurrence in persistent atrial fibrillation (PrAF) pts undergoing an initial PVI procedure. The DECAAF II trial was a prospective randomized controlled study evaluating the efficacy of MRI-guided fibrosis ablation compared to conventional ablation. Patient demographics, co-morbidities, medication regimens, baseline left atrial volume and atrial fibrosis were collected prior to ablation. After the procedure and 90-day blanking period, each participant submitted an ECG strip daily or when experiencing symptoms. A total of 826 pts were included, completed adequate follow up and had data regarding their HLD status. These pts were subsequently assessed for recurrent AA for 365 days post procedure. For this substudy, each patient was stratified into a HLD and non-HLD group irrespective of treatment modality. A covariate adjusted Cox regression model was used to assess determinants of AA recurrence. Lastly, a cox regression analysis was performed in patients taking HLD to assess for the effect of statins on AA recurrence. In the respective non-HLD and HLD groups, there was no statistical difference in mean left atrial volume (130±42 vs 135±38cc, p=0.08) and baseline fibrosis (19.0±7.4 vs 18.6±7.5%, p=0.43). However, there were statistically significant differences in age (61±9 vs 65±8 years, p=0.001), underlying hypertension (53.1 vs 69.1%, p=0.0001), diabetes (7.4 vs 14.5%, p=0.001), heart failure (16.8 vs 23.0%, p=.03) and obesity (52.4 vs 63.5%, p=0.002). When adjusted for these co-morbidities summarized in Table 1, analysis demonstrated HLD as a significant risk factor in procedural success and freedom from AA (Figure 1, p=0.02) with a hazard ratio of 1.30 (95% CI 1.05-1.61). Moreover, the use of statin therapy did not impact freedom from AA within the HLD group (Figure 1, p=0.51) with a hazard ratio of 0.83 (95% CI 0.58-1.12) HLD is an independent predictor of AA recurrence in PrAF pts undergoing PVI. However, statin therapy does not seem to improve AA recurrence after PVI in pts with PrAF and HLD.

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.

Revisiting exit block after entrance block: Investigation of ablation index-guided pulmonary vein isolation.

Unidirectional block, left atrium to pulmonary vein (LA-PV) entrance block without PV-LA exit block, has not been fully investigated in the setting of ablation index (AI)-guided pulmonary vein (PV) isolation (PVI). The aim of this study was to investigate unidirectional blocks during AI-guided PVI. After achieving entrance block, exit block was evaluated by pacing from the catheter placed in the PV. Local PV musculature capture without conduction to the LA was necessary to prove exit block. In total, 441 PVs (including nine left common PVs) from 113 consecutive patients (mean age: 71±12 years, 77 men, 61 paroxysmal atrial fibrillation cases) who underwent initial AI-guided PVI for atrial fibrillation were studied. Entrance block was achieved in all PVs. of the 247/441 (56%) PVs showing local PV musculature capture, 5/247 (2.0%) showed unidirectional blocks. Three of the five PVs (left superior and inferior PVs in one patient; right superior PV in another patient) showed LA-PV reconnection, requiring additional ablation to achieve bidirectional block during the procedure. Two of the five PVs (left superior and inferior PVs in one patient) showed LA-PV reconnection, and thereafter, LA-PV conduction became blocked again spontaneously, leading to bidirectional block without further ablation during the procedure. AI-guided PVI presented a low prevalence of unidirectional block (2%), using entrance block alone as the endpoint of PVI could therefore be justified.

Comparison of advanced generation cryoballoon ablation and ablation index-guided pulmonary vein isolation with non-pulmonary vein trigger induction test and additional ablation in paroxysmal atrial fibrillation.

An ablation index (AI)-guided pulmonary vein isolation (PVI) or 2nd generation cryoballoon (CB)-PVI has been shown to reduce the atrial fibrillation (AF) burden by 99% despite the absence of ablation of non-pulmonary vein (PV) triggers in patients with paroxysmal AF. The purpose of this study was to investigate the effects of PVI alone strategy using 2nd generation CB compared with AI-guided PVI with an additional induction test and subsequent AF trigger ablation. We investigated 223 patients with symptomatic paroxysmal AF who underwent an initial PVI between August 2018 and August 2020. The study patients were divided into 2 groups: CB-PVI without an induction test (CB-PVI alone group, n = 82) and AI-guided PVI with an induction test and subsequent additional ablation of non-PV triggers (AI-PVI plus group, n = 141). In the AI-PVI plus group, a total of 62 non-PV triggers were induced in 38 patients, and non-PV triggers in 22 patients were completely ablated. The procedure time and left atrium dwell time were significantly shorter in the CB-PVI alone group than AI-PVI plus group. There were no significant differences in the incidence of procedural complications between the 2 groups (P = 0.650). The AF free survival rate in the CB-PVI alone group and AI-PVI plus group was 80% vs. 80% at 24months (P = 0.969). An PVI alone strategy using advanced generation CB did not differ in the clinical outcomes compared with an AI-guided PVI strategy with an induction test and subsequent ablation of non-PV triggers in the patients with paroxysmal AF.

Abstract 10242: Right Atrial Function and Fibrosis in Relation to Successful Atrial Fibrillation Ablation

Introduction: Atrial remodeling, characterized by changes in atrial structure and function, is central to the development and maintenance of atrial fibrillation (AF). Besides left atrial (LA) remodeling, right atrial (RA) remodeling may also contribute to AF perpetuation, and its presence may affect clinical outcome of AF ablation. Bi-atrial remodeling in patients with AF is rarely assessed and data on the presence of RA fibrosis, the relationship between RA and LA fibrosis, and possible association of RA remodeling with AF recurrence after ablation is limited. Methods: 110 AF patients undergoing initial pulmonary vein isolation (PVI) were included in the present study. Patients were in sinus rhythm during cardiac magnetic resonance (CMR) imaging performed prior to ablation. LA and RA volumes and function (volumetric and strain) were derived from cine CMR images. The extent of LA and RA fibrosis was assessed from 3D late gadolinium enhancement images. AF recurrence was followed-up for 12 months after PVI using either 12 lead ECGs or Holter monitoring. Results: Arrhythmia recurrence was observed in 39 patients (36%) after the 90-day blanking period, occurring at a median of 181 (IQR: 122-286) days. RA remodeling parameters were not significantly different between patients with AF recurrence as compared to patients without AF recurrence after ablation, whereas LA remodeling parameters were (volume, emptying fraction and strain). LA fibrosis had a strong correlation with RA fibrosis (r=0.88, P &lt;0.001). Both, LA and RA fibrosis was not different between patients with and without AF recurrence. Conclusions: RA remodeling parameters were not predictive of AF recurrence after AF ablation. Bi-atrial fibrotic remodeling is present in AF patients and the amount of LA fibrosis had a strong correlation with the amount of RA fibrosis. The presence of bi-atrial fibrotic tissue may be an expression of disease state although no relation with AF recurrence after AF ablation was found.