Pulmonary Vein Isolation Techniques Research Articles

Intraprocedural and outcome findings in repeat left atrial procedures after pulsed field ablation for pulmonary vein isolation in paroxysmal and persistent atrial fibrillation

Abstract Background Pulsed Field Ablation (PFA) has emerged as a promising novel technique for pulmonary vein isolation (PVI) in the setting of atrial fibrillation. First outcome data revealed comparable success rates to radiofrequency and cryoablation. However, data on lesion dimensions and reconnection of PV after PFA potentially causing recurrence of AF is sparse. We, therefore report on pivotal reconnection sites and ablation extend after PFA-PVI. Methods All patients after PFA-PVI for paroxysmal or persistent AF at our center between September 2021 and October 2023 were included in this retrospective analysis. Baseline characteristics, procedural and outcome data were obtained. Furthermore, in all redo procedures of these patients lesion dimensions and the occurrence and location of PV gaps were evaluated. Results A total of 123 patients with atrial fibrillation underwent successful PFA-PVI during index procedure. The study cohort comprised [n= 52; 42%] paroxysmal and [n= 71; 58%] persistent atrial fibrillation cases. After a median follow-up of 123 (IQR 93-150) days recurrence of atrial arrhythmia (all AF) occurred in 9 [14. 5%] patients. Of these, 6 [9.6%] patients underwent a redo procedure due to recurrence of atrial fibrillation (3 PAF and 3 persAF [50%]; p=1). All left atrial maps and 24 PVs were analyzed. All 6 [100%] patients exhibited electrical reconnection of one or more pulmonary vein. Analysis of redo procedures revealed that the dimensions of PFA-induced lesions varied among patients: The right inferior pulmonary vein (RIPV) showed reconnection in all redo-patients (100%). Also frequent reconnection was observed for the RSPV (3 pts [50%]) and LIPV (2 pts [33%]). The gap size was 66±40% of the circumference in the reconnected RPVs and 61±31% in the reconnected LPVs. A roof-line lesion set was performed in 4 out of 6 pts (67%) due to the initially antral PV lesions affecting the posterior wall and LA roof potentially creating an isthmus for roof-dependent atrial tachycardia (AT). Conclusion Outcome data for PFA-PVI are comparable to other energy sources used for PVI. However, reconnection of PV also occurs after PFA-PVI. This retrospective analysis of redo procedures after initially successful PVI identified the RIPV as pivotal for reconnection. Furthermore, map analysis revealed that reconnection gaps extend to up to 2/3 of the initial circumferential PV ablation area. Furthermore, PFA seems to create new critical isthmuses potentially causing AT. No difference in reconnection was seen comparing PAF and persAF.

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).

Pulmonary vein isolation with additional substrate ablation for atrial fibrillation results in an increased risk for the development of atypical atrial flutter

Abstract Introduction Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) catheter ablation. Several extra pulmonary vein (PV) ablation strategies for substrate modification (PVI plus) have been employed to AF patients. It has not been proven that this approach decreases the recurrence of AF, and it could contribute to increase the risk of developing atypical atrial flutter. Methods Patients submitted to AF catheter ablation at our centre between 2005 and 2020 were included. Using logistic regression, we did a retrospective analysis of the association between the application of PVI plus strategies (such as ablation of the cavo tricuspid isthmus (CTI), ganglion plexus, isolation of the superior vena cava (SVC), mitral isthmus ablation and atrial roof line ablation) and the development of atypical flutter later submitted to ablation. Results Five hundred and seventy-five patients were included (64% males, age 57±12 years [between 14 and 81], 68.2% with paroxysmal AF) with > 1-year follow-up. Five hundred and five (87.8%) had PVI alone. From the 575 patients, 11 (1.9%) developed an atypical flutter during the follow-up, which was later submitted to ablation. The crude ODDS of a patient submitted to a PVI plus strategy developing atypical atrial flutter are 13.92 times higher than the one of those submitted to a stand-alone PVI technique, with a p value <0.001 (95% CI 3.96 – 48.87). When adjusted for age and history of heart failure, the ODDS of a patient submitted to a PVI plus strategy developing atypical atrial flutter are 16.29 times higher than the one of those submitted to a stand-alone PVI technique, with a p value <0.001 (95% CI 3.92 – 67.65). Conclusions Additional substrate ablation for AF significantly increases the risk of developing atypical auricular flutter.Characteristics of the study populationCharacterization of PIV plus strategies

Role of BMI on radiation dose in patients undergoing pulmonary vein isolation by pulsed field, cryoballoon and high-power-short-duration radiofrequency ablation

Abstract Background Different ablation modalities for pulmonary vein isolation (PVI) have been established. Since recent data from a randomized trial showed non-inferiority for pulse field ablation (PFA) vs. cryoballoon (CBA) or radiofrequency ablation (RFA) it seems reasonable to evaluate procedural parameters of these modalities in specific subgroups. Purpose The aim of this study was to evaluate radiation dose and procedural parameters in patients with body mass index (BMI) >26 kg/m² vs. ≤26 kg/m² undergoing PVI with different modalities. Methods Data of n=409 patients (140 PFA, 125 CBA, 144 RFA) having undergone PVI in three German centers for either paroxysmal or persistent atrial fibrillation were analysed. The primary endpoint was total radiation dose (Dose Area Product, DAP). Patients were analyzed with respect to BMI> vs. ≤26 kg/m² in PFA, CBA and RFA (with high-power short duration applications) groups, respectively. Secondary endpoints were radiation time and procedure time. Results The study included predominantly male patients (63.1%) with a mean age of 67.8±10.5 years. Cardiovascular risk factors were comparable within the groups, while the overall CHA2DS2-VASc-score was higher in CBA patients, which was largely influenced by a higher proportion of women in the CBA group. BMI was well balanced between the modalities (PFA: 28.7±5.6 kg/m² vs CBA: 28.5±6.0 kg/m² vs HPSD-RFA: 28.3±4.8 kg/m², p=0.78) as well as the proportion of patients with extreme obesity (BMI >30 kg/m²). The overall DAP was the lowest in the PFA group (370.2±274.6 µGym2) followed by HPSD-RFA (471.4±385.3 µGym2) and the highest in the CBA (1260.9±1053.5 µGym2) group. The radiation time was longest in the CBA group (16.6±17.0min) while being comparatively lower in PFA and HPSD-RFA groups (9.4±6.8 vs. 9.4±5.8 min). Procedure time was the shortest in the PFA group (79.6±30.5min), while being longest in the HPSD-RFA group (111.9±55.3 min). When stratifying patients according to BMI> 26 kg/m², there was a significant increase in DAP in all modalities, with the lowest mean increase in DAP in the PFA group (Δ143.84 µGym2), followed by HPSD-RFA (Δ329.54 µGym2) and the highest increase in the CBA group (Δ691.17 µGym2) (Figure 1). No difference was observed in radiation or procedure time when stratifying patients to BMI. (Figure 2) Conclusion Our study analyzing differences of radiation exposure according to elevated BMI among various PVI techniques shows that while there is a significant increase of DAP in patients with BMI >26 kg/m² in all modalities, the lowest increase is registered in the PFA collective. These results suggest that PVI performed with PFA, if available, or HPSD-RFA should be the energy sources of choice in obese patients with respect to radiation exposure.

Procedural performance and outcome after pulsed field ablation for pulmonary vein isolation: comparison with a reference radiofrequency database.

Pulsed field ablation (PFA) is a promising ablation technique for pulmonary vein isolation (PVI) with appealing advantages over radiofrequency (RF) including speed, tissue selectivity, and the promise of enhanced durability. In this study, we determine the procedural performance, efficacy, safety, and durability of PFA and compare its performance with a dataset of optimized RF ablation. After propensity score matching, we compared 161 patients who received optimized RF-guided PVI in the PowerPlus study (CLOSE protocol) with 161 patients undergoing PFA-guided PVI for paroxysmal or persistent atrial fibrillation (AF; pentaspline basket catheter). The median age was 65 years with 78% paroxysmal AF in the PFA group (comparable characteristics in the RF group). Pulsed field ablation-guided PVI was obtained in all patients with a procedure time of 47 min (vs. 71 min in RF, P < 0.0001) and a fluoroscopy time of 15 min (vs. 11 min in RF, P < 0.0001). One serious adverse event [transient ischaemic attack] occurred in a patient with thrombocytosis (0.6 vs. 0% in RF). During the 6-month follow-up, 24 and 27 patients experienced a recurrence with 20 and 11 repeat procedures in the PFA and the RF groups, respectively (P = 0.6 and 0.09). High-density mapping revealed a status of 4 isolated veins in 7/20 patients in the PFA group and in 2/11 patients in the RF group (35 vs. 18%, P = 0.3). Pulsed field ablation fulfils the promise of offering a short and safe PVI procedure, even when compared with optimized RF in experienced hands. Pulmonary vein reconnection is the dominant cause of recurrence and tempers the expectation of a high durability rate with PFA.

A zero-exchange approach for left atrial access in pulmonary vein isolation with pulsed field ablation.

Pulsed field ablation (PFA) has emerged as an innovative technique for pulmonary vein isolation (PVI). Typically, a transeptal puncture (TSP) with a standard sheath precedes a switch to the larger diameter sheath in the left atrium. This study aimed to describe the safety and feasibility of direct TSP using the large diameter Faradrive sheath before performing PVI with PFA. We prospectively enrolled 166 consecutive patients with paroxysmal or persistent atrial fibrillation (AF) undergoing PVI with PFA at our institution. TSP was performed in all cases with transesophageal echocardiography guidance, using the Faradrive sheath and a 98 cm matched Brockenbrough needle. The primary endpoint was the occurrence of pericardial tamponade during or within the first 48 h after the procedure. The secondary endpoint was the occurrence of any major complication. All 166 patients were included into the final analysis (44% female): 64% of patients had paroxysmal AF and 36% persistent AF (68 ± 11 years old, median CHA2DS2Vasc Score 3, median left atrial volume index 31). The median duration of the procedure was 60 min, median time to TSP was 15 min, and the median fluoroscopy dose was 595 cGy × cm2. The primary endpoint occurred in one patient: a non-TSP related pericardial tamponade, which was managed with pericardial puncture. Direct TSP with skipping sheath exchange using the large diameter Faradrive sheath for PVI with PFA was safe, feasible, and reduced costs in all patients. Large scale studies and registries are needed to verify this workflow.

One-year outcomes of wide antral cryoballoon ablation guided by high-density mapping vs. conventional cryoballoon ablation for atrial fibrillation: a propensity score-matched study.

Pulmonary vein isolation with wide antral ablation leads to better clinical outcomes for the treatment of atrial fibrillation, but the isolation lesion is invisible in conventional cryoballoon ablation. In this study, we aim to investigate the efficacy of the wide pulmonary vein isolation technique that includes the intervenous carina region, guided by high-density mapping, compared with pulmonary vein isolation alone without the mapping system. We conducted a propensity score-matched comparison of 74 patients who underwent a wide cryoballoon ablation guided by high-density mapping (mapping group) and 74 controls who underwent conventional cryoballoon ablation in the same period (no-mapping group). The primary outcome was a clinical recurrence of documented atrial arrhythmias for >30 s during the 1-year follow-up. Of 74 patients in the mapping group, residual local potential in the pulmonary vein antrum was found in 30 (40.5%) patients, and additional cryothermal applications were performed to achieve a wide pulmonary vein isolation. Compared with the no-mapping group, the use of the mapping system in the mapping group was associated with a longer fluoroscopic time (26.97 ± 8.07 min vs. 23.76 ± 8.36 min, P = 0.023) and greater fluoroscopic exposure [339 (IQR181-586) mGy vs. 224 (IQR133-409) mGy, P = 0.012]. However, no significant differences between the two groups were found in terms of procedural duration and left atrial dwell time (104.10 ± 18.76 min vs. 102.45 ± 21.01 min, P = 0.619; 83.52 ± 17.01 min vs. 79.59 ± 17.96 min, P = 0.177). The rate of 12-month freedom from clinical atrial arrhythmia recurrence was 85.1% in the mapping group and 70.3% in the no-mapping group (log-rank P = 0.029). Voltage and pulmonary vein potential mapping after cryoballoon pulmonary vein isolation can identify residual potential in the pulmonary vein antrum, and additional cryoablation guided by mapping leads to improved freedom from atrial arrhythmias compared with conventional pulmonary vein isolation without the mapping system. ChiCTR2200064383.

Temperature to time Catch-Up: a novel procedural endpoint to predict durable pulmonary vein isolation after cryoballoon ablation of paroxysmal atrial fibrillation.

Cryoballoon ablation is a widely used single-shot technique for pulmonary vein isolation (PVI) in the treatment of paroxysmal atrial fibrillation (AF). Procedural endpoints ensuring maximal PVI durability are important. To assess the performance of cryoablation procedural markers to predict long-term PVI. In a single center, consecutive patients who underwent redo ablation with high-density mapping for symptomatic AF recurrence after cryoballoon ablation were included and cryoballoon procedural data were collected, including temperature values at 30 and 60s, time to isolation, nadir temperature and the velocity of temperature decline estimated with the temperature/time catch-up point (T2T-Catch-Up) defined as positive when the freeze temperature in minus degree equals the time in seconds after cryoablation initiation (e.g. -15°C in the first 15s of the ablation impulse). 47 patients (62% male; 58.3 ± 11.2years) were included. Overall, 38 (80.9%) patients had ≥ 1 reconnected PV. Among 186 PVs, 56 (30.1%; 1.2 per patient on average) were reconnected. Univariate analysis revealed T2T-Catch-Up in 103 (56%) and more frequent in durably isolated than in reconnected PVs (93 [72%] vs 10 [19%], p < 0.0001). Among binary endpoints, T2T-Catch-Up had the highest specificity (82%) and predictive value for durable PVI at redo ablation (90%). In multivariable analyses, absence of T2T-Catch-Up (Odds-ratio 0.12, 95% CI [0.05-0.31], p < 0.0001) and right superior PV (Odds-ratio 3.14, 95% CI [1.27-7.74], p = 0.01) were the only variables independently associated with PV reconnection. T2T-Catch-Up, a new and simple cryoballoon procedural endpoint demonstrated excellent predictive value and strong statistical association with durable PVI.

'Single-shot' pulmonary vein isolation using a novel lotos pulsed field ablation catheter: a pre-clinical evaluation of feasibility, safety, and 30-day efficacy.

Pulsed field ablation (PFA) is emerging as a non-thermal, tissue-specific technique for pulmonary vein isolation (PVI) in atrial fibrillation therapy. This pre-clinical study aims to investigate the feasibility and safety of PVI using a novel PFA system including a nanosecond-scale PFA generator, a novel lotos PFA catheter, and a customized 12 Fr steerable sheath. A total of 11 Yorkshire swine were included in this study, with 4 in the acute cohort and 7 in the chronic cohort. Under general anaesthesia, transseptal puncture and pulmonary vein (PV) angiography was initially performed. The PFA catheter was navigated to position at the right and left PV antrum after the electroanatomic reconstruction of the left atrium. Biphasic PFA applications were performed on PVs in both the spindle-shaped and the lotos-shaped poses. Pulmonary vein isolation and PFA-associated safety were assessed 30 min after ablation in both cohorts and 30 days later in the chronic cohort. Detailed necropsy and histopathology were performed. Additional intracardiac echocardiography and coronary angiogram were evaluated for safety. All target PVs (n = 20) were successfully isolated on the first attempt. No spasm of coronary artery or microbubble was seen during the procedure. Eleven of 12 PVs (91.6%) remained in isolation at the 30-day invasive study. No evidence of PV stenosis was observed in any targets. However, transient diaphragm capture occurred in 17.6%. Histopathological examinations showed no evidence of collateral injury. This study provides scientific evidence demonstrating the safety and efficacy of the novel PFA catheter and system for single-shot PVI, which shows great potential.

Zero x-ray pulmonary vein isolation with heliostar radiofrequency balloon: efficacy and safety

Abstract Introduction Single shot pulmonary vein isolation techniques are currently an attractive and effective alternative to point-by-point ablation. The Heliostar® radiofrequency balloon is capable of producing single shot isolation with reduced procedure times and high efficacy and safety. A particular feature of this new balloon is its ability to be visualized on the Carto 3® navigation system, which makes it possible to reduce or even eliminate the use of X-rays (XR) in this type of procedure. Objectives Our objective was to demonstrate the efficacy and safety of pulmonary vein isolation with Heliostar® radiofrequency balloon without the use of XR. Methods Twenty-five patients with paroxysmal (68%) or persistent (32%) atrial fibrillation were prospectively included in our centre and underwent pulmonary vein isolation with radiofrequency balloon. Ten cases were performed without XR (40%), and the remaining 15 (60%) using fluoroscopy. All cases were performed under general anaesthesia and using the Carto 3® navigation system. Electroanatomical mapping was performed pre and post ablation in all cases. Mapping was performed in sinus rhythm. In cases without XR, intracardiac echocardiography was used to guide the transseptal puncture and the rest of the procedure. Technical and clinical data were collected. Cases with and without XR were compared. Results There were no complications in either group. All veins were successfully isolated, with 56% first pass isolation in the non-XR group versus 68% in the XR group (non-significant difference). The vein with the highest percentage of first pass isolations was the left inferior vein in both groups. Procedure times were similar (median left atrial dwell time of 34 minutes in the non-XR group and 36 minutes in the XR group, non-significant difference). There was also no difference in the median time to isolation from the start of radiofrequency application in each vein (10 seconds in both groups). Left atrial size was normal in most patients, and ventricular function was preserved, with no differences between the two groups. The non-XR group had a higher number of patients with left main trunk, but the XR group had a higher percentage of patients with persistent forms of atrial fibrillation. Conclusion Zero-XR pulmonary vein isolation with Heliostar® balloon is possible and safe, with similar efficacy and first pass isolation rate, similar procedure time and no relevant complications in our series.

Predictors of single shot pulmonary vein isolation with Heliostar radiofrequency balloon

Abstract Introduction Single shot pulmonary vein isolation techniques have emerged as an effective and safe alternative to point-by-point ablation, considerably reducing procedure times. The recent appearance on the market of the Heliostar® radiofrequency (RF) balloon offers a new option in this regard. The main predictors of single-shot isolation with this new device are unknown. Objectives Our objective was to evaluate as potential predictors of single-shot isolation the impedance drop, temperature rise and voltage reduction of the electrograms recorded by the balloon during radiofrequency application. Methods A total of 25 patients with paroxysmal (68%) or persistent (32%) symptomatic atrial fibrillation were prospectively included and underwent pulmonary vein isolation with Heliostar® RF balloon. Impedance and temperature parameters were collected from each of the applications performed in all veins. The voltage of the electrograms recorded by the Heliostar® RF balloon immediately before and after initiating the RF application in each vein was collected. The number of applications per vein was recorded and the single shot criterion was discriminated in each vein. A total of 92 veins were included for impedance and temperature analysis, and 59 veins for electrogram analysis (excluding veins in which the RF application was performed in atrial fibrillation). Impedance drop, temperature increase and electrogram voltage decrease during each application were analysed by logistic regression to correlate these parameters as potential predictors of single shot isolation. Results Single shot isolation was obtained in 64.1% of the veins. Applications that obtained persistent single shot isolation showed a higher impedance drop [22.5 ± 6.3 Ω vs 19 ± 5.3 Ω, p = 0.005] and a higher temperature rise [12.5 ± 4.4 ºC vs 10.3 ± 3.5 ºC, p = 0.008]. The voltage reduction of the electrograms collected by the balloon, on the other hand, did not differ significantly between the two groups [2.3 mV in single shot vs 2.2 mV in non-single shot applications, p = 0.4]. Univariate analysis by logistic regression showed impedance drop [OR per 1 Ω increase, 1.11, 95% CI 1.02-1.21, p = 0.007] and temperature increase [OR per 1°C increase, 1.15, 95% CI 1.02-1.3, p = 0.01] as significant predictors of single shot isolation. Conclusions Impedance drop and temperature rise during application were significant predictors of single shot isolation with Heliostar® RF balloon. The voltage reduction of the electrograms recorded by the balloon was not a predictor of single shot application.

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

Release of neuronal injury markers differs according to the technique of pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background Previous studies showed a release of neuronal injury markers during catheter ablation of atrial fibrillation using thermal energies such as radiofrequency or cryothermy. Pulsed field ablation (PFA), that is characterized by its tissue specificity, serves as an innovative technique for pulmonary vein isolation (PVI). Purpose To investigate the amount of neuronal injury marker release in patients undergoing first PVI using different ablation modalities. Methods We included 65 consecutive patients (age 69 ± 11 years, 52% females) that underwent PVI for the first time with either radiofrequency using standard ablation settings (RF; n = 11), radiofrequency with high-power short-duration (HPSD; n = 32) or PFA (PFA; n = 17) for atrial fibrillation. Protein S100B levels and Neuron-specific enolase (NSE) in coronary sinus blood were detected before and after PVI. The release of neuronal injury markers was assessed according to the ablation technique used. Results The change in high-sensitivity troponin (hsTnT) levels was similar in all groups (RF: Δ175.6±181.9 ng/l; HPSD: Δ153.1±233.5 ng/l; PFA: Δ181.1±257.6 ng/l; p=0.632). NSE was significantly released only in patients treated with PFA-PVI (25.2±13.4 to 45.2±24.9 ng/ml; p&amp;lt;0.001), but not in patients treated with RF-PVI or HPSD-PVI (both p&amp;gt;0.05). S100B was released in patients treated with RF-PVI (79.7±32.2 to 118.6±46.4 pg/ml; p=0.006) and PVI-PFA (80.6±38.1 to 138.1±82.7 pg/ml; p=0.002) after the procedure, while there was only a numerically increase in patients treated with PVI-HPSD (88.6±38.7 to 109.1±54.2 pg/ml; p=0.172). We detected no correlation between the release of neuronal biomarkers (Δ NSE and Δ S100B) and cardiac damage (Δ hsTnT) (all p&amp;gt;0.05). The ΔNSE/ΔhsTnT ratio (p&amp;lt;0.001), and the ΔS100B/ΔhsTnT ratio (p=0.002) was higher in patients undergoing PFA-PVI (ΔNSE/ΔhsTnT 0.19±0.20; ΔS100B/ΔhsTnT 0.75±1.35), than in patients undergoing RF-PVI (ΔNSE/ΔhsTnT 0.0±0.06; ΔS100B/ΔhsTnT 0.35±0.32) and HPSD-PVI (ΔNSE/ΔhsTnT 0.04±0.11; ΔS100B/ΔhsTnT 0.13±1.55). Conclusion The release of neuronal injury markers differs according to the technique used for PVI. Patients treated with PFA showed a higher release of neuronal injury markers compared to radiofrequency ablation, that was not explained by more myocardial damage. Future research needs to investigate the prognostic relevance in terms of atrial fibrillation recurrence of the neural injury induced by PFA compared to radiofrequency PVI.

Safety and durability of PFA for pulmonary vein isolation: comparison to a reference RF data base

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Pulse field ablation (PFA) is a promising ablation technique for pulmonary vein isolation (PVI) with appealing advantages over RF including speed, tissue selectivity and the promise of enhanced durability. We determined procedural efficiency, safety and durability of PFA for PVI and compared its performance to a dataset of optimized radiofrequency (RF) ablation. Methods 180 consecutive patients with paroxysmal or persistent AF undergoing PFA-guided PVI (conventional basket and flower applications for each vein) were included and compared to 180 patients who underwent optimized high-power RF-guided PVI in experienced hands in the POWER-PLUS study. Endpoints were procedural efficiency, safety, and the incidence of 4 isolated veins as evaluated by comprehensive activation mapping at repeat procedure for recurrence. Results Median age was 66 years with 72% paroxysmal AF (clinical characteristics comparable to the RF group). PVI was obtained in all patients with a procedure time of 47min (vs 71min in RF, p &amp;lt; 0.0001) and fluoroscopy time of 14min (vs 11min in RF, p &amp;lt; 0.0001). One serious adverse event (TIA) occurred in a patient with thrombocytosis (1/180, 0.6% vs 0% in RF). No patient experienced pericarditis (vs 1 in RF). During a median follow-up in the PFA group of 4.8 [3.0; 6.4] months, 8 patients underwent repeat for recurrence which revealed a status of 4 isolated veins in a quarter of the patients (2/8, 25%). In the POWER-PLUS study, repeat ablation for recurrence revealed durable isolation of all veins in half of the patients (7/13, 54%, p between groups 0.2). By the time of the EHRA symposium, results will be presented for 6 months in both groups. Conclusion PFA fulfills the promise of offering a short and safe PVI procedure, even when compared to optimized RF in experienced hands. Our data, showing PV reconnection as the dominant cause for recurrence, however temper the expectation of 100% durability. It remains to be seen, how operator expertise affects efficiency, safety, and durability of PFA.

Single-center outcome after ablation of atrial fibrillation using very high-power short duration pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation of atrial fibrillation is (AF) an established second line therapy for patients with symptomatic paroxysmal (PAF) and persistent AF (persAF). Novel ablation catheters with integrated thermocouples allow fast application of radiofrequency lesions with powers up to 90W. We aimed to describe primary and secondary outcomes after very high-power short duration (vHPSD) ablation. Methods 201 consecutive patients (127 PAF, 68 persAF, 6 longstanding persistent AF) underwent pulmonary vein isolation (PVI) using the QDOT Micro Catheter (Biosense Webster) with the ablation mode QMODE+ (90W, 4s, interlesion distance ≤4mm anterior, ≤6mm posterior). Results Mean age was 62±10 years, 38% were female, median CHA2DS2-VASc Score was 2 (0, 7). Median follow up duration was 196 (30, 461) days. 35% of patients had additional ablation of typical right atrial flutter. Primary success rate to achieve pulmonary vein isolation was achieved in all patients, no catheter-related complications (e.g., charring, steam pop) occurred. First pass isolation of all 4 PVs was achieved in 53% of patients, re-ablations were necessary in the carina regions (right: 27% of cases, left: 20%), 34% at multiple regions including the ridge, 12% in other regions around the PVs. Median procedure for PVI only were 110 (36-344) minutes. Arrhythmia-free survival was 79,3%. 21 patients underwent re-do procedures during follow-up showing most commonly showing gaps in the right PVs (RSPV 52%, RIPV 43%), the left inferior PV (48%), as well as the LSPV (38%) and the ridge (24%); with 91% of patients with recurrence showing more than one site reconnected. Conclusion Very high-power short duration ablation allows safe and quick pulmonary vein isolation. However, first pass isolation rate is low due to gaps in the carina regions. Arrhythmia-free survival is comparable to other pulmonary vein isolation techniques.

PO-02-094 ALL PULMONARY VEIN ISOLATION STRATEGIES ARE EQUALLY EFFECTIVE IN REDUCING THE RECURRENCE OF ATRIAL ARRHYTHMIAS

Ostial and antral pulmonary vein isolation techniques have different properties. In addition, there are differences between radiofrequency and cryoballoon ablation based on tissue contact characteristics. Finally, posterior wall isolation (PWI) has been proposed as an adjuvant to PVI because of embryological origin similarities. We examine the results of ostial and antral RF ablation, cryoballoon PVI and PWI adjunction in the DECAAF-II trial with regard to the recurrence of atrial arrhythmias after ablation. Patients with persistent AF from the DECAAF-II trial who underwent PVI only or PVI + PWI were included. All patients underwent LGE-MRI before ablation and 3 months after ablation. The electroanatomic maps at time of procedure displaying the location of ablation lesions were merged with baseline LGE-MRI images, and two reviewers analyzed and classified the resulting reconstructions. PVI were classified as ostial if the lesions were in the immediate proximity of the pulmonary veins’ ostium and as antral if the lesions included a portion of the antrum around the pulmonary veins. Patients with PVI + PWI were extracted as a separate group. Patients were followed up for a total of 18 months using daily single-lead smartphone ECG strips. The primary outcome of this analysis was recurrence of atrial arrhythmias after the 90-day blanking period. A total of 367 patients were considered for analysis. 211 patients underwent ostial PVI, 81 antral PVI, 31 had PVI + PWI, and 44 underwent cryoablation. Baseline characteristics were comparable in terms of age, sex, fibrosis percentage, comorbidity profile (hypertension, diabetes, hyperlipidemia, CAD, history of stroke), and medication history, except for a significant difference in history of heart failure (10.4% vs. 18.5% vs. 29% vs. 27.3%, p = 0.004) and prior AAD use (46.9% vs. 44.4% vs. 64.5% vs. 29.5%, p = 0.026). Recurrence rates were comparable among the four groups: 91 (43%) patients had recurrence in the ostial PVI group, 39 (48%) in the antral PVI group, 12 (39%) in the PWI group, and 22 (50%) in the cryoablation group (log rank P=0.76). In patients with persistent AF, all PVI techniques show equal efficacy in terms of atrial arrhythmia recurrence. Isolation of the posterior wall during ablation in persistent AF has no procedural advantage.

Study on the process of cardiomyocyte apoptosis after pulsed field ablation.

The development of pulsed field ablation (PFA) as a new technique for pulmonary vein isolation (PVI) has been advancing rapidly in recent years. My team's previous work has shown the safety and long-term efficacy of bipolar asymmetric pulses in animal experiments. However, in ongoing clinical trials, we have observed that atrial fibrillation (AF) recurs in some patients after surgery, but the rhythm returns to normal without surgical intervention after seven days, and there is no recurrence in the follow-up.Based on this observation, we have proposed the hypothesis that myocardial cell apoptosis may play a role in AF recurrence after PFA. Our team has designed animal experiments to verify this hypothesis and further investigate the process of PFA-induced cardiomyocyte apoptosis. Pulse field ablation was performed on 15 dogs and the animals were dissected at various time points after the operation (immediately, 3 days, 7 days, 30 days, and 150 days). To obtain ablation voltage maps, electroanatomic mapping was performed before and after ablation and before dissection. The ablation area was also subjected to HE and TUNEL staining to analyze apoptosis and pathological results. The edge area of the ablation in the pulmonary vein (PV) demonstrated continuous dynamic changes from 0 to 2 h after the operation and a slight expansion of the ablation range was observed in the long-term follow-up. Myocardial intima hyperplasia was observed from 0 to 7 days. Local apoptosis was detected from 0 to 2 h and massive, concentrated apoptosis was observed at 3 days. No recurrence of apoptosis was seen at 7 days, 30 days, and 150 days. The results of this study showed that after pulse field ablation (PFA), the central ablation area of the canine heart experienced immediate cardiomyocyte death. Meanwhile, cardiomyocytes in the edge ablation area underwent apoptosis, which began from 0 to 2 h post-operation and ended between 3 and 7 days. This process occurred simultaneously with intimal thickening.In the long-term follow-up group, there was no recovery of isolation and no recurrence of cardiomyocyte apoptosis, and no change was observed in the endomyocardial intima.

Ultra-microhistological study of nonthermal irreversible electroporation on the esophagus

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

Commentary to: "Comparing midterm outcomes" of Cox-Maze procedure and pulmonary vein isolation for atrial fibrillation after concomitant mitral valve surgery: A "systematic review".

There is no solid evidence from the literature that compare Cox-Maze with pulmonary vein isolation techniques for atrial fibrillation in the context of concomitant mitral valve surgery. Although the first is perhaps more effective and linked to higher freedom from atrial fibrillation, it is more invasive compared to the pulmonary isolation.

Characterization of circumferential antral pulmonary vein isolation areas resulting from pulsed-field catheter ablation.

The cornerstone of pulmonary vein (PV) isolation (PVI) is a wide-area circumferential ablation (WACA) resulting in an antral PVI area. Pulsed-field ablation (PFA) is a new nonthermal 'single-shot' PVI technique resulting in well-characterized posterior isolation areas. However, information on circumferential PVI area is lacking. Thus, we sought to characterize the circumferential antral PVI areas after PFA-PVI. Atrial fibrillation (AF) patients underwent fluoroscopy-guided PVI with a pentaspline PFA catheter. Ultra-high-density voltage maps using a 20-polar circular mapping catheter were created before and immediately after PVI to identify and quantify (i) insufficient isolation areas per antral PV segment (10-segment model) and (ii) enlarged left atrial (LA) isolation areas (beyond the antral PV segments) per LA region (8-region model). The PFA-PVI with pre- (5469 ± 1822 points) and post-mapping (6809 ± 2769 points) was performed in 40 consecutive patients [age 62 ± 6 years, 25/40 (62.5%) paroxysmal AF]. Insufficient isolation areas were located most frequently in the anterior antral PV segments of the left PVs (62.5-77.5% of patients) with the largest extent (median ≥0.4 cm2) located in the same segments (segments 2/5/8). Enlarged LA isolation areas were located most frequently and most extensively on the posterior wall and roof region (89.5-100% of patients; median 1.1-2.7 cm2 per region). Fluoroscopy-guided PFA-PVI frequently results in insufficient isolation areas in the left anterior antral PV segments and enlarged LA isolation areas on the posterior wall/roof, which both may be extensive. To optimize the procedure, full integration of PFA catheter visualization into three-dimensional-mapping systems is needed.