Antral Pulmonary Vein Isolation Research Articles

Abstract 4137447: Length of WACA line Affects 1 st Pass Success rates in PVI

Background: Standard ablation for atrial fibrillation consists of wide antral pulmonary vein isolation, efficacy for which depends on a contiguous series of ablation lesions. The larger a circumference ablated around the pulmonary veins, the more challenging it may be to ensure durable isolation, due to technical and anatomic factors, which may in turn contribute to higher rates of atrial fibrillation (AF) recurrence. The relationship between WACA size and success rates may inform procedural methods and optimize outcomes. Objective: To examine the relationship between length of WACA lines and ablation success in patients that have undergone a PVI ablation. Methods: We performed a single-center, retrospective analysis of a consecutive series of 258 patients who underwent 1 st pulmonary vein isolation (PVI) for the treatment of atrial fibrillation, between 1/1/2022 and 6/30/2023. Radiofrequency ablation (RFA) was performed using 50 W with a contact-force sensing irrigated catheter. Information on acute 1 st pass success for left and right vein was recorded. The length of each WACA line was traced out manually, following the center of the ablated lesions. Follow up information consisted of AF recurrence at three, six, and twelve months. Student t-test was used for comparison of means and Chi-square test was used for categorical variables. Results: All veins were successfully isolated in all patients. WACA 1 st pass success rates were 87% in the left veins, and 83% in the right veins. Right WACA lines were generally longer. In patients with Left WACA 1 st pass success, the average length of the WACA line was 94.8cm, compared to 100.1cm in the group without 1 st pass success (p=0.025). In patients with right WACA 1 st pass success, the average length of the WACA line was 105.8cm, compared to 110.6cm in the group without 1 st pass success (p=0.07). When evaluating post PVI patients for recurrence of AF at 1year, there was a non-statistically significant association of AF recurrence with longer combined L+R WACA lines during index PVI (205.5cm vs 197.0cm, p=0.065). Conclusion: Longer WACA lines during index PVI are associated with failure of 1 st pass isolation. Further study is needed to address the mechanism by which longer WACA lines affect ablation efficacy, whether due to technical factors reflecting something intrinsic to underlying substrate.

Significance of the local largest bipolar voltage for the optimized ablation strategy using very high-power short duration mode.

Very high-power short-duration (vHPSD) ablation creates shallower lesions, potentially reducing efficacy. This study aims to identify factors leading to insufficient lesions during pulmonary vein antral isolation (PVAI) with vHPSD-ablation and to develop an optimized PVAI strategy using this technology. PVAI was performed on 41 atrial fibrillation patients using vHPSD-ablation (90 W/4 s). Lesion parameters were recorded and analyzed to identify predictors of insufficient lesions. An optimized PVAI strategy, based on these predictors, was tested in subsequent 42 patients. In total, 3099 RF-applications, including 103(3.3%) insufficient lesions, were analyzed. First-pass PVAI was achieved in 19/40(47.5%) right PVs and 24/41(58.5%) left PVs. Multivariate analysis identified significant predictors of insufficient lesions: local largest bipolar voltage (Bi-V), average contact force, baseline impedance, impedance drop, temperature rise, inter-lesion distance (ILD), and anatomical location (carina or not). An ILD:4-6 mm increased the risk of insufficient lesions 2.2-fold, and lesions at the carina increased it 3.6-fold for both ILD < 4 mm and ILD:4-6 mm. Local largest Bi-V was the strongest predictor for insufficient lesions. The optimized PVAI approach, utilizing vHPSD-ablation with an ILD < 4 mm in non-carinal areas with Bi-V < 4 mV, and high-power ablation-index guided ablation (HPAI, 50 W, ablation-index:450-550) in remaining areas, achieved first-pass PVAI in 92.7% of right PVs and 88.1% of left PVs, using vHPSD-ablation in approximately 65% of total RF-applications. The optimized PVAI achieved significantly higher first-pass PVI rate (p < .0001) with shorter ablation time (p = .04). Appropriate use of vHPSD and HPAI, based on local largest Bi-V and anatomical information, may achieve high first-pass PVAI rates in shorter ablation time with minimal energy delivery.

Procedural findings and follow-up results of catheter ablation of atrial fibrillation in patients after radiation therapy for breast cancer

Abstract Backround Data on breast cancer radiation therapy (RT) associated atrial cardiomyopathy and its potential role in the pathophysiology of atrial fibrillation (AF) is very limited. Objectives To investigate the effect of breast cancer radiotherapy (RT) on atrial cardiomyopathy and its possible role in the pathophysiology of atrial fibrillation. What is the therapeutic success of antral pulmonary vein isolation (PVI) with possible substrate modifications (CFAE) in patients with breast cancer radiation therapy and paroxysmal or persistent atrial fibrillation. Methods We searched the institution’s data base for patients who received RT for breast cancer and underwent subsequently 3D mapping guided AF ablation. Intraprocedural mapping data and short- and long-term results of ablation were evaluated according to "no low voltage" and "low voltage" present. Low voltage amplitudes in bipolar electrograms were defined as &amp;lt;0.5 mV for endocardial maps created during SR and &amp;lt;0.3mV during AF. Ablation strategy comprised pulmonary vein isolation (PVI) ± additional substrate modification according to the mapping results. Follow Up (FU) was evaluated using repetitive 7-days Holter ECG and clinical visits. Results We included 45 patients (all female, 70.9±7.2 years) with paroxysmal or persistent AF (n=18 and n=27). In 3D mapping, 60% of the patients (27/45) showed left atrial low voltage (LV group) with the majority showing low voltage in the anterior wall of the left atrium (LA) in 18 of 45 patients (40%). PVI with ablation of complex fractionated signals (CFAE) was predominantly performed (18/27). After one ablation, 33.3% (9) of the patients in the LV group were recurrence-free and after an average of 1.9 ablations, freedom from recurrence was achieved in 21 patients with low voltage (77.8%). In 18 patients, no low voltage was detected (NLV group) and PVI only was performed in the majority (14/18). In this NLV group, 61.1% (11) of the patients were recurrence-free after one ablation and freedom from recurrence was achieved in 72.2% (13) after an average of 1.2 ablations. Conclusion Thoracic radiation therapy in patients with breast cancer can lead to low voltage in the LA with the predominant low voltage location being the anterior wall of the LA. An extended ablation strategy (PVI &amp; CFAE) can show good treatment options in these patients with atrial fibrillation, with high freedom from recurrence after a mean of two ablation procedures.Freedom from recurrence after ablationCharacteristics of left atrium (LA)

Catheter ablation for atrial fibrillation: indications and future perspective.

Recent advances in techniques, technologies and proven superiority over anti-arrhythmic drugs have made catheter ablation the cornerstone of management for atrial fibrillation (AF), which has shown a steady increase in prevalence in the ageing population worldwide. The aim of therapeutic interventions is to achieve stable sinus rhythm that would improve the quality of life and reduce the risk of AF-associated complications. Pulmonary veins (PVs) were first described as the source of initiation of ectopic triggers driving AF, which led to the establishment of PV isolation (PVI) as the most widely practiced procedure to treat AF. Antral PVI is still recognized as the stand-alone ablation strategy for newly diagnosed paroxysmal AF (PAF). However, in non-PAF patients, PVI seems to be inadequate and several adjunctive strategies, including ablation of left atrial posterior wall and non-PV triggers, AF mapping and ablation of rotors and drivers, ethanol infusion of vein of Marshall and renal denervation, etc. have been reported with mixed results. Recent trials have also documented the benefits of early rhythm control in preventing cardiovascular events in addition to slowing the progression of PAF to more persistent forms. Similarly, very late relapse of the arrhythmia after successful PVI has drawn attention to the critical role of non-PV triggers and highlighted their relevance as potential ablation targets during repeat procedures. Ablation technology is also under constant evolution with the introduction of non-thermal energy sources and new tools to create durable lesions. This review summarizes the indications, advancements, and future perspective of AF ablation.

Distribution of antral lesions with the novel size-adjustable cryoballoon for pulmonary vein isolation and the differences based on left atrial remodeling.

The novel cryoballoon with 28 mm or 31 mm adjustable diameters, aims to achieve a wide antral pulmonary vein isolation (PVI). However, the distribution of antral lesions and their variations based on left atrial (LA) remodeling require further clarification. We evaluated 22 patients (67 [59.5-74.8] years, 19 males) who underwent PVI of atrial fibrillation (AF) (13 paroxysmal AF [PAF] and 9 non-PAF) using size-adjustable cryoballoons. LA electro-anatomical mapping was performed post-PVI with three-dimensional mapping systems. We assessed the shapes of the LA and pulmonary veins (PVs) and the distribution of isolated areas (IAs), comparing the results between PAF and non-PAF patients. In the left PVs (LPVs), the distance between the PV orifice and IA edge (PVos-IA) was larger on the roof and posterior segments (~15 mm) but relatively smaller on the anterior segment near the PV ridge (<10 mm). For the right PVs (RPVs), it was more extensive in the posterior segment (10-15 mm). Comparing PAF and non-PAF, there were no significant differences in the PVos-IA except for the right posterior-carina segment, antrum IA (LPVs: 5.9 ± 1.6 vs. 5.8 ± 0.8 cm², p = .81; RPVs: 4.8 ± 2.3 vs. 4.8 ± 1.2 cm², p = .81), distances between the right and left IAs on the LA posterior wall (LAPW), and un-isolated LAPW area (9.0 ± 4.9 vs. 9.9 ± 2.5 cm², p = .62). No individual PVIs were observed in either group. Two patients exhibited overlapping IAs on the roof, and one patient who underwent 31 mm balloon applications for all PVs exhibited an LAPW isolation. The size-adjustable cryoballoon achieved a wide antral PVI even in non-PAF patients.

Ablation of drivers in patients with persistent atrial fibrillation refractory to pulmonary vein antral isolation: Target characteristics and 3-year outcomes.

Ablation of drivers in patients with persistent atrial fibrillation refractory to pulmonary vein antral isolation: Target characteristics and 3-year outcomes.

Anti- and pro-fibrillatory effects of pulmonary vein isolation gaps in human atrial fibrillation digital twins

Although pulmonary vein isolation (PVI) gaps and extrapulmonary vein triggers contribute to recurrence after atrial fibrillation (AF) ablation, their precise mechanisms remain unproven. Our study assessed the impact of PVI gaps on rhythm outcomes using a human AF digital twin. We included 50 patients (76.0% with persistent AF) who underwent catheter ablation with a realistic AF digital twin by integrating computed tomography and electroanatomical mapping. We evaluated the final rhythm status, including AF and atrial tachycardia (AT), across 600 AF episodes, considering factors including PVI level, PVI gap number, and pacing locations. Our findings revealed that antral PVI had a significantly lower ratio of AF at the final rhythm (28% vs. 56%, p = 0.002) than ostial PVI. Increasing PVI gap numbers correlated with an increased ratio of AF at the final rhythm (p < 0.001). Extra-PV induction yielded a higher ratio of AF at the final rhythm than internal PV induction (77.5% vs. 59.0%, p < 0.001). In conclusion, our human AF digital twin model helped assess AF maintenance mechanisms. Clinical trial registration: https://www.clinicaltrials.gov; Unique identifier: NCT02138695.

Abstract 14702: Roles of Atrial Mass Reduction and Gaps on the Anti-Atrial Fibrillatory Effects of Pulmonary Vein Isolation: A Computational Modeling Study

Background: Although pulmonary vein isolation (PVI) is the basis of atrial fibrillation (AF) catheter ablation (AFCA), the conditional changes of an anti-AF effect and the wave-dynamic mechanism are poorly understood. Therefore, we compared the effects of PVI based on the ablation circumference, width, and number or locations of gaps with or without amiodarone at the same condition in realistic computational modeling of human AF. Hypothesis: An anatomical level of PVI and characteristics of the PVI gap would affect the anti-AF effects of the AFCA. Methods: We included 50 patients (76.0% persistent AF) who underwent AFCA. Realistic AF modeling reflecting the computed tomography (CT) and the electroanatomical map was performed on each patient. We compared the AF defragmentation rate (DeFR; change to atrial tachycardia (AT) or termination), termination rate (TnR), and changes in the dominant frequency (DF) and the number of phase singularities (PSs) based on the PVI level (antral vs. ostial), PVI width (single vs. 3х width), number and location of 2-mm PVI gaps with or without amiodarone (10mM). We randomly assigned the number and location of the PVI gaps to the AF models. Results: The antral PVI had a significantly higher DeFR (p for trend &lt;0.001) and TnR (p for trend &lt;0.001) than the ostial PVI, PVI gaps, or baseline AF. However, there was no difference depending on PVI width. Among the PVI gaps, the DeFR (p for trend&lt;0.001) decreased as the gap number increased. Additional amiodarone increased DeFR (p=0.003) and TnR (p=0.034) and reduced DF (p&lt;0.001) and the number of PSs (p&lt;0.001) with PVI-gap, especially with a single PVI-gap. Conclusions: In this realistic computational modeling study with integrated patients’ atrial anatomy and electrophysiology, the atrial mass reduction depending on the anatomical PVI level, number of PVI gaps, and additional antiarrhythmic drug significantly affected the AF maintenance mechanisms.

Abstract 11697: Combined-Energy Pulmonary Vein Isolation and Posterior Wall Isolation for Persistent Atrial Fibrillation: Results of a 3-year Follow-Up

Introduction: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation for paroxysmal atrial fibrillation (AF), but the optimal ablation strategy for persistent AF (PsAF) remains controversial. Hypothesis: The purpose of this study was to investigate whether combined-energy cryoballoon (CB) PVI and radiofrequency (RF) left atrial posterior wall isolation (LAPWI) at index ablation of PsAF yields higher success than PVI alone. Methods: Patients with persistent AF (n = 186) who underwent catheter ablation between 2016 and 2019 at a single large academic medical center were retrospectively reviewed. Patients with congenital heart disease or prior left atrial ablation or surgery were excluded. Combined-energy ablation (n=92) consisted of CB antral PVI followed by RF roof and floor lines to achieve LAPWI, along with isolation inside the box as needed. The control group had PVI only (n=94) with either CB (n=57) or RF (n=37). The primary endpoint was 12-, 24-, and 36-month freedom from any documented atrial tachyarrhythmia over 30 seconds after a 90-day blanking period following catheter ablation, compared by Kaplan-Meier analysis. Secondary endpoints included AF burden, procedural parameters, and complications. Results: The primary endpoint of 12-month freedom from any atrial tachyarrhythmia was higher for the combined-energy group vs the control group (79.1% vs 58.2%, p = 0.009). This improvement was sustained at 24 months (63.0% vs 45.8%) and at 36 months (60.3% vs 43.1%) and remained significant after adjustment for clinical covariates (adjusted HR 0.45, 95% confidence interval 0.22-0.95; p = 0.03). There was no significant difference in procedure time or complication rates, however fluoroscopy time was shorter with combined-energy ablation (p&lt;.001). Conclusions: In this single center experience, combined-energy CB-PVI and RF-LAPWI was associated with reduced AF recurrence compared to PVI with a single energy source.

Dynamics of left and right atrial strain after radiofrequency ablation in patients with paroxysmal and persistent atrial fibrillation

Aim. To assess the dynamics of left (LA) and right atrium (RA) strain after antral pulmonary vein isolation in patients with paroxysmal and persistent atrial fibrillation.Methods. The study included 57 subjects (31 men and 26 women) aged of 55.4±9.8 years. Patients were divided into 2 groups: group 1 with paroxysmal atrial fibrillation (n=40; 70%) and group 2 with persistent atrial fibrillation (n=17; 30%). All patients were treated (were undergone) with antral isolation of the pulmonary veins. Speckle-tracking echocardiography at sinus rhythm was performed before interventional treatment, after 3 days, 3 months and one year. The reservoir, conduit and contractile LA function and peak longitudinal RA strain were analyzed.Results. In both groups, reservoir (p&lt;0.001), conductive (p&lt;0.001) and contractile LA functions (p&lt;0.001 and p=0.001) decreased significantly in the early postoperative period. LA mechanics recovered after 3 months in all patients and were comparable to the level before and one year after radiofrequency ablation. RA strain was significantly increased in the early postoperative period. RA strain was significantly higher at one year follow-up period compared with baseline.Conclusion. Catheter ablation has a damaging effect on the LA - inhibition of reservoir, conductive and contractile functions in the early postoperative period, while the RA strain is intensified. LA strain is recovered in 3 months after radiofrequency ablation and remains comparable with the baseline level at one year follow-up. Reservoir and conduction function of LA and longitudinal deformation of RA are better in the patients with a stable sinus rhythm for a year after ablation compared with patiens who had a tachyarrhythmia recurrence.

Efficacy of different variants of endocardial balloon cryoablation in patients with persistent atrial fibrillation

Aim. To study the effectiveness of “extended” cryoballon ablation in patients with a persistent form of atrial fibrillation (AF) and to determine the risk factors for AF recurrence after cryoablation.Methods. The study included 89 patients (62±10 years, 24 [27%] men) with a persistent form of AF. The patients were randomized into two groups: in the 1st, the pulmonary veins (PV) cryoablation was performed (n=48 [53.9%]); in the 2nd, the PV cryoablation was performed in combination with cryoablation of the posterior wall of the left atrium (n=41 [46.1%]). The number of patients at high risk of thromboembolic events predominated in Group 2 (p=0,03). There is a high frequency of taking antiarrhythmic drugs of class III in this group (p=0.018). The follow-up period was 12 months. Clinical efficacy was assessed during a survey and daily ECG monitoring at face-to-face visits after 3, 6 and 12 months.Results. Antral isolation of PV was achieved in all 89 (100%) patients in both groups. In group 2, the average number of applications in the posterior wall of the PV was 10 [9; 13]. The effectiveness of cryoablation in group 1 by the end of the 12-month follow-up period was 54.2%, in group 2 - 56.1%. The complication rate (6.7%) in both groups did not differ statistically (p=0.683). The risk of arrhythmia recurrence didn’t depend on the strategy of cryoablation in postablation period (p=0.834). When conducting a single-factor analysis, a statistically significant effect on the probability of AF recurrence in the period of 3-12 months in group 1 was caused by AF recurrence in the blind period (95% confidence interval (CI): 1.5-27.7, p=0.013), in group 2 belonging to the female sex (95% CI: 1.2-24.6, p=0.032) and AF relapse in the blind period (95% CI: 1.5-128.5, p=0.020). During multivariate analysis in group 2, a statistically significant influence on the risk of AF recurrence in the period of 3-12 months was exerted by belonging to the female sex (hazard ratio (HR) 7.84; 95% CI 1478-42,23; p=0.016) and the presence of early AF recurrence (HR 20.36; 95% CI 1.99-208.23; p=0.011).Conclusion. Extended cryoablation in terms of efficiency and safety was comparable with the standard cryoablation. Early recurrence of AF (in the first 3 months after the intervention) turned out to be an independent risk factor for AF recurrence in the long-term period up to 12 months after cryoablation in both groups.

Insights into level of pulmonary vein isolation using pulsed-field ablation for atrial fibrillation and unexpected effects in the posterior wall

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Pulse field ablation (PFA) has emerged as an effective, safe and efficient tool for pulmonary vein isolation (PVI). Purpose We studied the extent of PVI, specifically the isolation of PV antrum, carina and left atria’s posterior wall after PFA with an ultrahigh density mapping (UHD). Methods We involved the first patients referred for atrial fibrillation (AF) ablation treated with a PFA multispline catheter. PFA-lesion extension was assessed with a voltage-map UHD mapping performed before and immediately after PVI. Results Sixty-one consecutive patients underwent PVI with PFA (62±10 year old, 23 women, 39 paroxysmal AF). Four out of 61 patients were excluded because their posterior wall was isolated with extra aplications on purpose. Acute results involved a 100% success of PVI and the only safety issue was a pericardial effusion in one patient managed conservatively. Mean procedure and fluoroscopy times were 59±39 min and 16±5 min, respectively. UHD immediately after PVI revealed early reconnection just in one vein (1/228 veins). PFA created wide antral circumferential lesions without electrical activity registered by UHD mapping inside the isolation area. There were no notch-like normal voltage areas at the anterior or posterior side of carinas. As a result of the PVI with this technology, it was observed the existence of a narrow corridor in the posterior wall in 8 patients (14%) and in another 8 cases right and left antral ablation converged at the posterior wall creating an unexpected isolation area. There was a significant relationship between LA posterior inter-carina distance and posterior wall´s level of isolation (77,1±7mm, no affectation; 68,8±7mm narrow corridor; 60,3±1mm posterior wall isolation (fig 1); p=0.036). Finally, it was a significant linear correlation between posterior inter-carina distance and the distance between the ipsilateral, antral levels of isolation at the posterior wall (fig 2, r=0.79, p=0.001) Conclusion(s) PFA creates wide antral circumferential PVI lesions involving the ipsilateral veins carina. Nevertheless, in small left atria it can create an undesired isolation or a narrow corridor in the posterior wall.

Relationship between the left atrial and pulmonary vein effective refractory period and the development of early atrial fibrillation recurrence after radiofrequency pulmonary vein isolation. First results

Aim. To assess the relationship between the left atrial (LA) and pul­monary vein (PV) effective refractory period and the development of early atrial fibrillation (AF) recurrence after radiofrequency pul­monary vein isolation (PVI).Material and methods. The study included 35 patients with persistent AF refractory to antiarrhythmic therapy (AAT). In all patients, LA and PV effective refractory period (ERP) was assessed, followed by radiofrequency antral PVI. Depending on the ERP values, the patients were divided into 2 groups. Group 1 (n=15) included patients with mean LA and PV ERP values ≥240 ms, while group 2 (n=20) consisted of patients with mean LA and PV ERP values &lt;240 ms. The evaluation of early AF recurrence, depending on the obtained ERP values, was carried out in the first 3 months.Results. We obtained following ERP values: group 1 — LA (LA ap­ pendage) 252±8,9 ms; left superior PV (LSPV) — 252±12,1 ms; left inferior PV (LIPV) — 257,3±8,15 ms; right superior PV (RSPV) — 254,6±11,3 ms; right inferior PV (RIPV) — 260±9,05 ms; group 2 — LA 230±12,1 ms; LSPV — 205±10,5 ms; LIPV — 186,6±22,05 ms; RSPV — 212,2±14 ms; RIPV — 218,8±11,1 ms. During the 3-month follow-up of group 1 patients, there were no recurrences after PVI. Group 2 had 7 early AF recurrences. Correlation analysis revealed a significant inversely proportional relationship (-0,349; p=0,03) between ERP values and the recurrence rate in the groups.Conclusion. The first results demonstrate an inversely proportional relationship between the mean PV and LA ERP and the development of early AF recurrence, which makes it possible to consider the PV and LA ERP &lt;240 ms as a likely predictor of early AF recurrence. However, this fact requires the study continuation with an increase in the sample and an appropriate statistical analysis.

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.

Prospective randomized comparison between upgraded ‘2C3L’ vs. PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design

In randomized studies, the strategy of pulmonary vein antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for the ablation of PeAF. The PROMPT-AF study (clinicaltrials.gov 04497376) is a prospective, multicenter, open-label, randomized trial using a 1:1 parallel-control approach. Patients (n = 498) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI, and 3 linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavotricuspid isthmus. The follow-up duration is 12 months. The primary end point is freedom from atrial arrhythmias of >30 seconds, without antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation.

Effect of Catheter Ablation Using Pulmonary Vein Isolation With vs Without Posterior Left Atrial Wall Isolation on Atrial Arrhythmia Recurrence in Patients With Persistent Atrial Fibrillation

Pulmonary vein isolation (PVI) alone is less effective in patients with persistent atrial fibrillation (AF) compared with paroxysmal AF. The left atrial posterior wall may contribute to maintenance of persistent AF, and posterior wall isolation (PWI) is a common PVI adjunct. However, PWI has not been subjected to randomized comparison. To compare PVI with PWI vs PVI alone in patients with persistent AF undergoing first-time catheter ablation. Investigator initiated, multicenter, randomized clinical trial involving 11 centers in 3 countries (Australia, Canada, UK). Symptomatic patients with persistent AF were randomized 1:1 to either PVI with PWI or PVI alone. Patients were enrolled July 2018-March 2021, with 1-year follow-up completed March 2022. The PVI with PWI group (n = 170) underwent wide antral pulmonary vein isolation followed by posterior wall isolation involving linear ablation at the roof and floor to achieve electrical isolation. The PVI-alone group (n = 168) underwent wide antral pulmonary vein isolation alone. Primary end point was freedom from any documented atrial arrhythmia of more than 30 seconds without antiarrhythmic medication at 12 months, after a single ablation procedure. The 23 secondary outcomes included freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures, freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures, AF burden between study groups at 12 months, procedural outcomes, and complications. Among 338 patients randomized (median age, 65.6 [IQR, 13.1] years; 76.9% men), 330 (97.6%) completed the study. After 12 months, 89 patients (52.4%) assigned to PVI with PWI were free from recurrent atrial arrhythmia without antiarrhythmic medication after a single procedure, compared with 90 (53.6%) assigned to PVI alone (between-group difference, -1.2%; hazard ratio [HR], 0.99 [95% CI, 0.73-1.36]; P = .98). Of the secondary end points, 9 showed no significant difference, including freedom from atrial arrhythmia with/without antiarrhythmic medication after multiple procedures (58.2% for PVI with PWI vs 60.1% for PVI alone; HR, 1.10 [95% CI, 0.79-1.55]; P = .57), freedom from symptomatic AF with/without antiarrhythmic medication after multiple procedures (68.2% vs 72%; HR, 1.20 [95% CI, 0.80-1.78]; P = .36) or AF burden (0% [IQR, 0%-2.3%] vs 0% [IQR, 0%-2.8%], P = .47). Mean procedural times (142 [SD, 69] vs 121 [SD, 57] minutes, P < .001) and ablation times (34 [SD, 21] vs 28 [SD, 12] minutes, P < .001) were significantly shorter for PVI alone. There were 6 complications for PVI with PWI and 4 for PVI alone. In patients undergoing first-time catheter ablation for persistent AF, the addition of PWI to PVI alone did not significantly improve freedom from atrial arrhythmia at 12 months compared with PVI alone. These findings do not support the empirical inclusion of PWI for ablation of persistent AF. anzctr.org.au Identifier: ACTRN12616001436460.

A macroreentrant biatrial tachycardia via the posterior interatrial connection emerged after extensive catheter ablation for paroxysmal atrial fibrillation

Recent electrophysiological studies have demonstrated the existence of an epicardial connection via posterior interatrial fibers, which connect the antrum of the right pulmonary veins and the right atrium (RA).1 This connection represents a potential mechanism for the interference of circumferential antral pulmonary vein isolation.2 The posterior interatrial connection has also been reported as a critical limb of biatrial reentrant circuits in a rare condition with interatrial septal incisions after mitral valve surgery.

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.

Impact of very wide antral pulmonary vein isolation on esophageal temperature changes during pulsed field ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Esophageal thermal injury (ETI) is a serious drawback of available energy sources for atrial fibrillation (AF) ablation, especially on the posterior left atrial (LA) wall. Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety advantages over existing methods due to its unique myocardial tissue specificity sparing the esophagus. Objective To evaluate esophageal temperature changes during very wide antral pulmonary vein isolation (PVI) using the PFA system. Methods Thirteen consecutive AF patients (62% with paroxysmal AF; age: 61 years; 70% male) underwent first-time PFA under deep sedation. Eight pulse trains (2kV/2.5 sec, bipolar, biphasic, 4x basket/flower configuration each) were delivered to each pulmonary vein (PV). Extra pulse trains in the flower configuration were added for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with an S-shaped esophageal temperature probe. Results A median of 32 (IQR 32;32) and 8 (IQR 8;9) pulse trains for PVI and vWACA with a procedural time and catheter dwell time of 67 min (IQR 61-69) and 17 min (IQR 16-18) were applied. PFA with vWACA resulted in consecutive posterior LA wall isolation in 11/13 patients. Fluoroscopically, the esophagus coursed near the right PVs in 2/13, left PVs in 8/13 and mid-posterior wall position in 3/13 patients. Maximum TESO increase from baseline was 0.8 ±0.9 °C. However, no clinically relevant TESO changes occurred (Table 1). On short-term, all patients remained asymptomatic for sore throat, cough, or other symptoms potentially related to ETI. No esophago-duodenoscopy was necessary. Conclusion PFA of the PVs and lesion extension to the posterior LA wall demonstrated clinically non-significant TESO changes and has the potential to eliminate the risk of a thermal damage to the esophagus.

Characterization of the circumferential cevel of the pulmonary vein isolation area using pulsed-field catheter ablation: Spatial distribution and extent of insufficient and excessive isolation areas

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The cornerstone of pulmonary vein isolation (PVI) is a wide area circumferential ablation (WACA) resulting in an isolation area encompassing the PV antrum. Pulsed field ablation (PFA) is a new non-thermal "single-shot" PVI device with promising success rates. However, the circumferential level of its PV isolation area is still unknown. Objective To characterize the circumferential acute PV isolation area by assessing the spatial distribution (qualitative analysis) and extent (quantitative analysis) of insufficient PV antral and excessive LA isolation areas. Methods In this study, patients with paroxysmal or persistent atrial fibrillation (AF) underwent PVI with a pentaspline PFA catheter. Before and immediately after PVI, ultra-high-density (UHD) voltage maps using a 20-polar circular mapping catheter were created. The insufficient isolations areas per antral PV segment (10-segment model) and excessive isolation areas per LA region (8-region model) were quantified. Results Between November – December 2021, in forty consecutive patients (age 62 ± 6 years, 28/40 [70%] male, LA 41 ± 4 mm) acute PVI using PFA was achieved and pre (5469 ± 1822 points) and post mapping (6809 ± 2769 points) was performed. The anterior antral PV segments of the left PVs were the most frequent locations of insufficient isolation areas (Table 1, Figure 1). The largest extent of insufficient isolation areas at the PV antral level was located again on the anterior parts of both left PVs (Figure 2A), but also in the anterior lower segment of the right inferior PV (Figure 2B). The posterior wall and roof region of both LA sides were the most frequent locations of excessive isolation areas (Figure 4). The extent of this excessive isolation at the roof and the posterior wall on both LA sides even resulted in a connection of the both-sided low voltage areas in 18% and 8%, respectively. Conclusion When using PFA to achieve a circumferential antral PVI, efforts should be made to enhance anterior antral PV segment and prevent excessive posterior wall and roof ablation. For further optimizing the procedure, full integration of PFA catheter visualization into 3D-mapping systems is needed.