Redo Procedures Research Articles

Cryoablation of atrial fibrillation in "very severe" obese patients (BMI ≥ 40): Indications, feasibility, procedural safety and efficacy, and clinical outcome (the ICE-Obese Extreme).

Management of atrial fibrillation (AF) in very severe obese patients is challenging. Cryoballoon ablation (CBA) represents an effective rhythm control strategy. However, data in this patient group were limited. Highly symptomatic AF patients with body mass index (BMI) ≥ 40 kg/m2 who had failed antiarrhythmic drug therapy and electrocardioversion and failure to achieve targeted body-weight-reduction underwent CBA. Data of 72 very severe obese AF patients (Group A) and 129 AF patients with normal BMI (Group B, BMI < 25 kg/m2) were consecutively collected. Group A had significantly younger age (60.6 ± 10.4 vs. 69.2 ± 11.2 years), higher BMI (44.3 ± 4.3 vs. 22.5 ± 1.6 kg/m2). Procedural pulmonary vein isolation (PVI) was successful in all patients (2 touch-up ablation in Group A). Compared to Group B, Group A had similar procedural (61.3 ± 22.6 vs. 57.5 ± 19 min), similar fluoroscopy time (10.1 ± 5.5 vs. 9.2 ± 4.8 min) but significantly higher radiation dose (2852 ± 2095 vs. 884 ± 732 µGym2). We observed similar rates of real-time-isolation (78.6% vs. 78.5%), single-shot-isolation (86.5% vs. 88.8%), but significantly longer time-to-sustained-isolation (53.5 ± 33 vs. 43.2 ± 25 s). There was significantly higher rate of puncture-site-complication (6.9% vs. 1.6%) in Group A. One-year clinical success in paroxysmal AF was (Group A: 69.4% vs. Group B: 80.2%; p < .001), in persistent AF was (Group A: 58.1% vs. Group B: 62.8%; p = .889). In Re-Do procedures Group A had a numerically lower PVI durability (75.0% vs. 83.6%, p = .089). For very severe obese AF patients, CBA appears feasible, leads to relatively good clinical outcome.

A cost-consequence analysis comparing three cardiac ablation strategies for the treatment of paroxysmal atrial fibrillation

Background and aims Cardiac ablation is a well-established method for treating atrial fibrillation (AF). Pulsed field ablation (PFA) is a non-thermal therapeutic alternative to radiofrequency ablation (RFA) and cryoballoon ablation (CRYO). PFA uses high-voltage electric pulses to target cells. The present analysis aims to quantify the costs, outcomes, and resources associated with these three ablation strategies for paroxysmal AF. Methods Real-world clinical data were prospectively collected during index hospitalization by three European medical centers (Belgium, Germany, the Netherlands) specialized in cardiac ablation. These data included procedure times (pre-procedural, skin-to-skin and post-procedural), resource use, and staff burden. Data regarding complications associated with each of the three treatment options and redo procedures were extracted from the literature. Costs were collected from hospital economic formularies and published cost databases. A cost-consequence model from the hospital perspective was built to estimate the impact of the three treatment options in terms of effectiveness and costs. Results Across the three centers, N = 91 patients were included over a period of 12 months. A significant difference was seen in pre-procedural time (mean ± SD, PFA: 13.6 ± 3.7 min, CRYO: 18.8 ± 6.6 min, RFA: 20.4 ± 6.4 min; p < .001). Procedural time (skin-to-skin) was also different across alternatives (PFA: 50.9 ± 22.4 min, CRYO: 74.5 ± 24.5 min, RFA: 140.2 ± 82.4 min; p < .0001). The model reported an overall cost of €216,535 per 100 patients treated with PFA, €301,510 per 100 patients treated with CRYO and €346,594 per 100 patients treated with RFA. Overall, the cumulative savings associated with PFA (excluding kit costs) were €850 and €1,301 per patient compared to CRYO and RFA, respectively. Conclusion PFA demonstrated shorter procedure time compared to CRYO and RFA. Model estimates indicate that these time savings result in cost savings for hospitals and reduce outlay on redo procedures. Clinical practice in individual hospitals varies and may impact the ability to transfer the results of this analysis to other settings.

Assessing the arrhythmogenic propensity of fibrotic substrate using digital twins to inform a mechanisms-based atrial fibrillation ablation strategy

Atrial fibrillation (AF), the most common heart rhythm disorder, may cause stroke and heart failure. For patients with persistent AF with fibrosis proliferation, the standard AF treatment—pulmonary vein isolation—has poor outcomes, necessitating redo procedures, owing to insufficient understanding of what constitutes good targets in fibrotic substrates. Here we present a prospective clinical and personalized digital twin study that characterizes the arrhythmogenic properties of persistent AF substrates and uncovers locations possessing rotor-attracting capabilities. Among these, a portion needs to be ablated to render the substrate not inducible for rotors, but the rest (37%) lose rotor-attracting capabilities when another location is ablated. Leveraging digital twin mechanistic insights, we suggest ablation targets that eliminate arrhythmia propensity with minimum lesions while also minimizing the risk of iatrogenic tachycardia and AF recurrence. Our findings provide further evidence regarding the appropriate substrate ablation targets in persistent AF, opening the door for effective strategies to mitigate patients’ AF burden.

Characterisation of ablation strategies at redo catheter ablation for atrial fibrillation and predictors of arrhythmia recurrence: results from the AFREDO registry

Abstract Background Patients who have undergone prior pulmonary vein isolation (PVI) for atrial fibrillation (AF) often require a repeat ablation for AF recurrence. The optimal ablative strategy for the redo procedure and predictors of AF recurrence thereafter remain largely unknown. Purpose We aimed to characterise the ablation strategies applied at re-PVI and identify possible predictors of AF recurrence. Methods Our single-centre, retrospective study included all consecutive patients who underwent first redo PVI at our centre from 2017 to 2022. Inclusion criteria required at least one available follow-up visit within the first 12 months after the redo procedure. Ablation strategies of the initial and redo procedure were captured. Kaplan-Meier curves were used to illustrate time of AF recurrence, as classified by predictors of outcome determined by multivariable regression analyses. Results We included 215 patients (39.1% female) with a median age of 66.6 years (IQR 58.6-73.2) at the time of redo procedure. The initial PVI was cryoablation in 39.9%, RFA in 57.7% and surgical ablation in 2.4%. After the initial procedure, 55.8% had paroxysmal AF and 44.2% had persistent AF. At the redo procedure, 25.1% of patients were found to have no PV reconnection, whereas 20.5% had a single reconnected PV, and 54.4% had two or more reconnected PVs. A left-sided flutter ablation was performed in 18.8%, a left atrial (LA) roof line in 16.9%, a posterior mitral isthmus line in 5.2%, an anterior mitral isthmus line in 27.9%, and a posterior box lesion in 8.4%. Overall, 34.4% of patients showed areas of low-voltages in the redo procedure. Patients with areas of low voltages were less likely to have any reconnected PVs in the redo-procedure (p&amp;lt;0.001). After the second ablation procedure, 54.0% experienced AF recurrence. Univariable regression analysis revealed moderate (p=0.006) or severe (p= 0.015) LA dilatation, persistent AF (p=0.005), and posterior LA low voltage areas (p=0.011) as significant predictors of AF recurrence after the redo procedure. The number of reconnected PVs at the re-PVI did not predict AF recurrence (p=0.1090). As illustrated in Fig. 1 and 2, patients with paroxysmal AF experienced less AF recurrence compared to those with persistent AF (log-rank p=0.0025). Moreover, moderate or severe LA dilatation at baseline was associated with more frequent AF recurrences (log-rank p=0.0279). Conclusion A significant proportion of patients undergoing re-PVI experienced AF recurrence. We found that persistent AF and moderate or severe LA enlargement emerged as significant predictors of AF recurrence after the redo procedure. Although PV reconnection was observed in more than two thirds of patients at the re-PVI, it did not predict AF recurrence thereafter. However, patients without PV reconnection had significantly more low-voltage areas, which may be indicative of a different AF recurrence mechanism in this subgroup.Figure 1:Type of AFFigure 2:LA dilatation

Treatmen of atrial fibrillation with cryoballoon pulmonary vein isolation - results of a 5-year follow-up

Abstract Background Atrial fibrillation is the most common arrhythmia in the general population and cryoballoon ablation is gradually becoming a first-line treatment. However, data regarding long-term outcomes after this procedure are still lacking. Aim The goal was to show the results of a long-term follow-up following the cryoballoon pulmonary vein isolation in patients with atrial fibrillation (AF). Methods A total of 126 patients were included in the study of which 77.0% had paroxysmal atrial fibrillation (PAF). Successful treatment outcome was defined as AF recurrence-free survival with stabile sinus rhythm during 5 years after the procedure. A treatment failure was defined as symptomatic AF recurrence with ECG verification (12 lead ECG or AF lasting &amp;gt;30s by Holter EKG). The patients on antiarrhythmic therapy and those who underwent a redo pulmonary vein isolation procedure were also included. Results Following cryoballoon pulmonary vein isolation in a 5-year period 52.4% of patients were in stable sinus rhythm without AF recurrence. With redo pulmonary vein procedures a total of 61.9% of patients were without AF recurrence. Together with antiarrhythmic drugs 57.9% of patients were in sinus rhythm without AF recurrence in a 5-year period. With redo pulmonary vein isolation and antiarrhythmic drugs a total of 73.8% of patients were without AF recurrence. There was a statistically significant difference regarding AF recurrence between patients who underwent redo pulmonary vein isolation and those who did not (p=0.006). In patients with PAF, 62.9% remained without AF recurrence, and 79.4% underwent a redo procedure. In patients with persistent atrial fibrillation (PersAF), 41.4% were without AF recurrence, and 55.1% underwent a redo procedure. The difference between PAF and PersAF was statistically significant (p=0.009). Conclusion Data from our center show good long-term results of cryoballoon pulmonary vein isolation in patients with atrial fibrillation. The procedure is especially successful in patients with PAF.1 The use of redo procedures is justified as it increases the long-term success rate.

Multicenter retrospective evaluation of a patient-tailored electrogram-based ablation strategy using an artificial intelligence software in repeat atrial fibrillation ablation procedures

Abstract Background While pulmonary vein isolation (PVI) is the gold standard approach of treatment of atrial fibrillation (AF), the optimal strategy in case of AF recurrences for redo patients is not well established. Several studies described the usefulness of ablating in atrial regions exhibiting abnormal electrograms, i.e. spatio-temporal dispersion, during AF and an artificial intelligence (AI) electrograms (EGMs)-based software solution has been developed and validated to obtain real-time adjudications of multipolar electrograms in de novo patients. Purpose This study sought to evaluate the novel AI-EGMs-based software approach for redo-AF ablation procedures. Methods This study was a retrospective, multicentric, nonrandomized study. Patients with recurrent symptomatic AF were enrolled in 7 European centers. Redo ablation procedures were performed using the AI software and acute and long-term outcomes after ablation were evaluated. Results A total of 117 patients with refractory symptomatic AF admitted for redo procedure were included with 30% paroxysmal, 42% short-standing persistent and 28% long-standing persistent AF at the time of the redo procedure. During the index procedures, a previous PVI ablation was performed in all patients while additional ablation such as lines and EGM-based ablation was performed in 64 patients (55%). Out of 117 patients, 30 (26%) presented with structural heart disease, 61 (52%) with hypertension, 31 (26%) with a BMI &amp;gt;30, 16 (14%) a sleep apnea syndrome and 24 (20%) had an antiarrhythmic treatment at the time of the procedure. The average AF history was 6.54 ± 4.15 years with an average sustained duration equal to 25 ± 62 months. AI-EGMs-based AF ablation was performed in all patients and easily integrated in the physicians’ workflow during redo procedures. AF termination, i.e. AF regularization or sinus rhythm conversion, occurred in 82/117 patients (71%) with sinus rhythm conversion by ablation in 79/117 patients (68%). After a mean follow-up of 11 ± 5 months, 81% of patients were free from documented AF, with or without antiarrhythmic drugs (AADs) after one redo procedure and 60% of patients were free from any documented atrial arrhythmia, with or without AADs, after one redo procedure per patient. Furthermore, we observed that 77%, 84% and 82% of patients were free from documented AF with or without AADs in paroxysmal, short-standing and long-standing persistent AF patients respectively, and that 71%, 59% and 49% of patients were free from any documented atrial arrhythmia with or without AADs in paroxysmal, short-standing and long-standing persistent AF patients respectively. Conclusions This retrospective study reports that patient-tailored spatiotemporal dispersion ablation is a relevant and standardized approach for repeat AF ablation. This was obtained with an AI-EGMs-based software solution, which may be added to the operative workflow of redo AF procedures.

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

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

Pattern of reconnection after isolation of the pulmonary veins with a pulsed-field ablation

Abstract Background Pulsed Field Ablation (PFA) has proven is efficacy for pulmonary vein isolation (PVI) with an acute success in 99.9% of PVI and few major complications (1.6% of patients). (1) However, in redo procedures, the durability of the PVI was 63% at a median of 6 month in a study of Kueffer and al. (2) Purpose The purpose of this study is to analyze the pattern of these reconnections in the redo procedures. Methods We retrospectively analyzed the data among the patients that had a PVI with PFA in our institution between 1 October 2022 and 1 October 2023 who were referred for a recurrence of a tachyarrhythmia. Results Of 350 patients treated for PVI with PFA, 14 patients (4%) were referred for a recurrence of tachyarrhythmia. Among them, three (21%) were female and the median age was 72 years old [IQR 69-78]. The Chadvasc score was &amp;gt; 2 in 7 (50%) patients and the DR flash score was &amp;gt; 3 also in 7 (50%) patients. The patients were referred for paroxysmal AF (4/14 patients), persistent AF (5/14 patients), typical flutter (2/14 patients) or atypical flutter (3/14 patients). All patients had a high resolution 3D electro-anatomical mapping, in a median time of 7,4 months [IQR 5,1-11,8]. The median left atrium volume was 169 mL [IQR 150-180] and 66% of the pulmonary veins were isolated. Only two patients (14%) had durable PVI in all their veins. Two of the patients had a posterior box with their PVI and the box was blocked at 7 and 13 months after the PFA. The reconnections of the pulmonary veins was mainly in the anterior aspect of the right superior PV (6/19 reconnections, 32%). There were two typical shapes of reconnection, the « missing petal » and the « collar » patterns. Conclusion In a redo procedures at 7 months after a PFA, 14% of the patients had durable PVI and 66% of the veins were isolated. The reconnections were mainly in the anterior right superior PV and had often a typical « missing petal » or « collar» patterns.Percentage ReconnectionsPatterns Reconnections

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

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

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).

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

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

Simplification of resetting response in slow/fast atrioventricular nodal reentrant tachycardia: the 3 catheters approach

Abstract Background The resetting response is a maneuver that helps identify the anterograde limb of slow/fast atrioventricular nodal reentrant tachycardia (AVNRT). The actual described maneuver involved a 5 catheters approach, and the related complications are poorly described.(1) Purpose We describe a simplified approach with 3 catheters and the related complications of the maneuver. Methods A quadripolar catheter was placed in the His bundle region; a decapolar catheter in the coronary sinus (CS) and a 4 mm tip non irrigated or irrigated catheter was used for pacing and ablation. An 8.5 French Sl0 sheath was used to ensure contact and stability. In confirmed slow/fast AVNRT using the fast pathway as the retrograde limb (earliest retrograde atrial activity located in the parahisian region), a single decremental atrial extrastimulus was delivered at the lower part of the triangle of Koch and 2-3 cm inside the CS on the roof. Pacing maneuver was started near the end of the QRS complex and decremented by 10 ms per interval. The higher atrial signal with the best A/V ratio on the CS catheter was used as sense reference for resetting response. The end point of ablation was non inducibility. Results Ten patients were included in a 4-month period, comprising 2 redo procedures. The maneuver was not performed in 4 patients (40%) due to non-sustained tachycardia. Atrial fibrillation was induced in 2 patients (20%) during the maneuver systematically due to an atrial extrastimulus preceding the H potential (negative HA interval). In the 4 remaining patients with successful resetting response, the HA interval in successful ablation spot varies between 31 to 82 ms. The involved anterograde limb was the right extension in 3 (75%) and the left extension in 1 (25%). Conclusion Resetting response can be performed with a 3 catheters approach, the main limitation is non sustained tachycardia, and atrial fibrillation induced by short coupled extrastimulus.Resseting response in LIE and RIE

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

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

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

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

Impact of early atrial arrhythmia recurrence on long-term CryoPVI success

Abstract Background According to current guidelines, the occurrence of atrial fibrillation (AF) recurrence within the first 90 days after pulmonary vein isolation (PVI) should not indicate re-do procedures. Accordingly, a 90-day blanking period is usually accepted. However, data suggests that early atrial arrhythmia relapses during the blanking period have an impact on the efficacy. The optimal period for indicating a re-ablation therefore remains unclear. Methods We prospectively analyzed consecutive AF patients who underwent cryoballoon PVI (CryoPVI) in a single-center cohort between 2018 and 2023. We divided patients into four groups according to arrhythmia recurrence (recurrence between 0-30 days, recurrence between 30-60 days, recurrence between 60-90 days and no recurrence within the first 90 days). CryoPVI was performed in a standardized procedure. At 3, 6, 12, 18, 24 and 36 months after CryoPVI follow up was performed. Efficacy endpoint was the occurrence of symptomatic atrial arrhythmia relapse. Results During the study period 1179 patients underwent a first CryoPVI. Of these, 84 patients (7.1%) had atrial arrhythmia relapse between 0-30 days, 38 patients (3.2%) had atrial arrhythmia relapse between 30-60 days, and 38 patients (3.2%) had a relapse between 60-90 days. Overall, 1019 (86.4%) patients didn’t have an atrial arrhythmia relapse between 0-90 days after CryoPVI. Primary efficacy endpoint incidence after 36 months was significantly higher in patients who experienced atrial arrhythmia relapse within the first 90 days (between 0-30 days 62.5% vs. between 30-60 days 70.1% vs. between 60-90 days 77.9% vs. no recurrence ≤ 90 days 41.6%, p&amp;lt;0.0001). Conclusion Atrial arrhythmia relapse within the first 90 days is associated with a reduced long-term efficacy of CryoPVI. Re-ablation should be indicated regardless of the time of recurrence.

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

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

Electrogram dispersion mapping for repeat ablation in patients with persistent atrial fibrillation

Abstract Background/Introduction While pulmonary vein isolation (PVI) is a key guideline endpoint for atrial fibrillation (AF) ablation, strategies for repeat ablation are debated, particularly when PVs are isolated. Electrogram dispersion mapping identifies dynamic substrates using existing catheters, remote from the PVs and may confer benefit to additional ablation. Purpose To describe the outcome of repeat ablation using electrogram mapping to identify areas of mechanistic significance in persistent AF patients. Methods Patients undergoing repeat ablation for persistent AF were recruited from two international centers. A five spline catheter was used to mark areas of electrogram dispersion before any ablation using previously described criteria. After confirming PVI, or re-isolation of PVs if necessary, ablation of all dispersion areas was performed. If termination to atrial tachycardia (AT) occurred, this was mapped using conventional methods. Patients who terminated to sinus underwent reinduction pacing protocols to map any further AT or AF inducible. Patients were followed up at 12 months with continuous event monitors, and beyond 12 months based on local guidelines. Results In total, 167 AF patients were enrolled: age 66 ± 8 yrs; 32% female; mean LA diameter 4.8 cm. PVI was present in 108 (64%) of patients. All patients underwent LA mapping, and 75 (45%) underwent right atrial (RA) mapping. Patients had an average of 3.2 LA and 1.4 RA ablation sites. The total number of dispersion sites in patients was similar in patients with and without PVI, (4.1 ± 2 and 3.6 ± 1 respectively). AF terminated in 144 patients (86%), with an overall conversion to sinus rhythm obtained by ablation in 42% of the patients. Patients were followed for an average of 2.92 ± 0.9 years. At 12 months, 159 (95%) patients were AF free, and 124 (74%) remained free of atrial arrhythmia. Of those patients, only 8 (5%) had AF, with 35 (21%) recurring with AT or atrial flutter (AFL). Of the 70 patients who terminated to sinus with repeat ablation, only 2 (2.9%) recurred with AF and 26 (37.1%) had recurrence of atrial arrhythmia (AF/AT/AFL) as a whole throughout the entire follow-up period (P&amp;lt;0.05). Patients with and without PVI at redo procedure did not have a statistically significant difference in recurrence of AF (Figure 1, P = 0.80) nor recurrence of atrial arrhythmia (Figure 2, P = 0.63) during total follow up time by log rank test. Conclusions In a difficult to treat population of persistent AF patients requiring a repeat ablation procedure, electrogram mapping led to rates of freedom from AF at 12 months similar to first time ablation series. Additionally, those with PVI present at time of procedure had similar benefit from this approach compared to those with reconnected veins. This is the largest demonstration of a technique that confers benefit in a PVI isolated subgroup of purely redo ablations for persistent AF.Figure 1:Percent AF FreeFigure 2:Percent AF/AT/AFL Free

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

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

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)