90-day Blanking Period Research Articles

Pulsed Field Ablation in Atrial Fibrillation: Initial Experience of the Efficacy and Safety in Pulmonary Vein Isolation and Beyond

Regional differences in pulsed field ablation (PFA) adoption for pulmonary vein isolation (PVI) with additional posterior wall ablation (PWA) in Asia remains unknown. We hereby report our experience on the safety and efficacy of PFA in AF ablation. Consecutive AF patients who underwent PFA from September 2022 to January 2024 were included. The primary efficacy endpoint was freedom from atrial arrhythmia recurrence after a 90-day blanking period at 12 months. Safety endpoints included 30 days of all-cause death, cardiac tamponade, stroke, myocardial infarction, and heart failure hospitalization. One hundred and one (72.3% males, 79.2% pAF) patients underwent PFA for AF. Thirty-one (30.7%) had structural heart disease with mean LVEF of 57.4 ± 8.1% and CHA2DS2-VASc score of 1.4 ± 1.3. Twenty-nine (28.7%) underwent additional PWA (PVI + PWA) using PFA. PWA was acutely successful in all patients. Patients who underwent PWA were more likely to have persistent AF and require general anesthesia and electroanatomic mapping (all p < 0.05). Total PFA applications for PVI, LA dwell time, procedural time, and fluoroscopy time were similar between the PVI-only and PVI + PWA groups (all p > 0.05). The 1-year atrial arrhythmia recurrence rates were 10% for pAF and 21% for the persistent AF group. The primary efficacy endpoint was not significantly different between the PVI-only and PVI+PWA groups (12-month KM estimates 90.3% [95% CI, 83.3–97.3] and 82.8% [95% CI, 68.1–97.4], respectively). There were no complications related to PFA use. PFA can be safely, effectively, and efficiently adopted for AF ablation. Additional PWA, if pursued, had similar procedural metrics to the PVI-only strategy without increased complications.

Timing of early recurrence of atrial fibrillation during the blanking period after catheter ablation for persistent atrial fibrillation and implications for long-term success: a multicentre study

Abstract Background After catheter ablation (CA) for atrial fibrillation (AF), early recurrences of AF (ERAF) that occur within a 90-day post-ablation "blanking period" are considered to represent transient post-ablation pro-arrhythmia. Purpose To determine if the timing of early recurrence of AF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence after CA for persistent AF (PsAF). Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018. All patients had undergone pre-CA DCCV. Incidences of ERAF during the post-CA blanking period were reviewed, and patients were categorised into three groups based on the timing of last episode of ERAF during the blanking period: (1) no ERAF (reference population); (2) last ERAF <30 days post-CA; (3) last ERAF 31-90 days post-CA. The primary outcome was long-term recurrence of atrial arrhythmia, i.e. time to first recurrence of atrial arrhythmia occurring beyond the first 90 days after CA. Patients who had ERAF and exited the blanking period in AF (i.e. those with immediate recurrence at 90 days) were excluded from this analysis. Results 331 patients were identified from five centres. 206 patients had no ERAF during follow-up, 124 patients had ERAF during the blanking period, and in one patient the presence of ERAF was not documented. Of the 124 patients experiencing ERAF during the 90-day post-CA blanking period, the timing of the last episode was known in 122 patients (Table 1). Of these, 58 patients exited the 90-day blanking period in AF and were excluded. Over median post-CA follow-up of 590 days, 147 patients (54%) experienced the primary outcome. Compared with Group 1 (no ERAF), ERAF within each of the time periods was associated with a statistically significant progressively increased risk of long-term recurrence (Group 2, last ERAF <30 days post-CA: hazard ratio [HR] 1.95 [95% CI 1.15-3.31]; Group 3, last ERAF 31-90 days post-CA: HR 4.86 [95% CI 2.13-11.08]; Figure 1). Conclusion ERAF during the traditional 90-day post-CA blanking period is associated with long-term AF recurrence, with later recurrence within the 90-day period conferring greater risk. Patients with ERAF during the blanking period may need to be considered for earlier repeat intervention where clinically appropriate.

Efficacy and safety of catheter ablation for paroxysmal atrial fibrillation as first-line therapy vs. after drug failure -analysis from Japan Nationwide Ablation (J-AB) Registry-

Abstract Background Catheter ablation is an effective rhythm control therapy for atrial fibrillation (AF). Recent advancements in technology have improved the efficacy and safety of this procedure. Current European Society of Cardiology and Japanese Circulation Society guidelines recommend that catheter ablation (CA) for patients with paroxysmal AF (PAF) after failure of drug therapy is classified as Class I, and CA as first-line therapy is categorized as Class IIa. However, there are limited clinical studies directly comparing these groups. Objective This study aimed to compare the efficacy and safety of CA as first-line therapy vs. those after failed drug therapy using data from the Japan Nationwide Ablation (J-AB) Registry led by the Japanese Heart Rhythm Society. Methods Detailed data of patients who underwent catheter ablation for PAF extracted from the J-AB registry were analyzed. Patients were divided into two groups: those who underwent CA as first-line therapy (First-line group) or those who underwent CA after failed drug therapy (Drug failure group). Patients’ characteristics, efficacy and safety of CA were compared between the two groups. Efficacy was assessed by evaluating the recurrence rate of any atrial arrhythmia within one year after the 90-day blanking period, and major safety outcomes were set as severe bleeding complication, stroke, and gastrointestinal disorders during the perioperative period. Result This analysis included 5,011 cases with a median age of 69 years (range 61-75) and 35% females. Comparing patient characteristics between the first-line therapy group (n = 3,447) and the drug failure group (n = 1,564), there are no statistically significant differences between the two groups except in left atrium diameter in echocardiogram (LAD) (38 [34-42] mm vs. 38 [34-43] mm, P <0.001), serum creatinine levels (0.8 [0.7-1.0] mg/dl vs. 0.9 [0.7-1.0] mg/dl, P <0.001), and beta-blocker usage (38.2% vs. 46.7%, P <0.01). A total of 501 recurrence events were observed in this analysis during a median follow-up of 365 [254-390] days. Recurrence rates did not statistically differ between the two groups (log-rank P=0.49). After adjusting for contributing factors with age, gender, body mass index, LAD, and left ventricular ejection fraction in echocardiogram using a multivariate Cox proportional hazards model, efficacy outcomes showed no significant difference between the two groups (adjusted hazard ratio; 1.06 95% confidence interval; 0.88-1.28, P = 0.55). Besides, the two groups had no significant difference in major safety outcomes. Conclusions Catheter ablation as the first-line therapy for paroxysmal atrial fibrillation showed a similar recurrence rate of atrial arrhythmias and adverse events compared to those who underwent catheter ablation after drug failure.

Prediction of atrial fibrillation recurrence after ablation: the impact of machine learning and recurrence during the blanking period

Abstract Introduction Pulmonary vein isolation is superior to antiarrhythmic drugs for rhythm control in patients with atrial fibrillation (AF). Nevertheless, recurrences within the first year are still significant. Several clinical risk scores were developed to predict AF recurrence; however, despite good results in development cohorts, the results in external validation are usually poor, limiting the general applicability of these scores. Purpose We aimed to develop machine learning (ML) models to predict AF recurrences within the first year after catheter ablation and compare their performance with conventional risk scores. Methods We used a retrospective dataset of a tertiary hospital center, including all consecutive patients submitted to the first AF ablation between 2017 and 2021. The dataset included 76 features: patient characteristics, medical history, baseline echocardiography, calcium score, procedure variables, and early recurrence (ER) during the 90-day blanking period. The outcome was defined as the occurrence of an electrocardiographically documented late recurrence (LR) of atrial tachycardia/AF > 30s between 3-12 months. Three different supervised ML models (penalized logistic regression, random forests, and XGBoost) were developed on the training cohort, and hyperparameters were tuned using 10-fold cross-validation. A testing dataset was held out to estimate the final performance (25%). The following risk scores were calculated: APPLE, CAAP-AF, and BASE-AF2 (the last includes ER). Areas under the curve (AUC) of receiver operating characteristic curves were compared using DeLong’s test. Results 679 patients were included: 62.7% males, median age of 59±16 years, and 78.2% with paroxysmal AF. The median time from diagnosis to ablation was 2±4 years. 74.2% underwent radiofrequency ablation and the remaining cryoablation. ER occurred in 12.5%, and most of these patients also experienced LR (68.7 vs 19.6% in those without ER, p<0.001). LR was observed in 25.6%. The XGBoost model showed the best performance with an AUC 0.774, 95% confidence interval (CI) 0.688–0.844) outperforming existing scores (picture 1): APPLE score AUC 0.607, 95% CI 0.562–0.653, p-value<0.001; CAAP-AF score AUC 0.622, 95% CI 0.576–0.668, p-value=0.002; BASE-AF2 AUC 0.628, 95% CI 0.581–0.675, p-value= 0.003. Variable importance analysis showed a significant drop in the performance of the models when ER was not considered, indicating its high importance in predicting LR (picture 2). Conclusions Recurrence during the blanking period was the most important predictor of LR in our population. The ML model was superior to conventional risk scores. ML models might be an essential tool to improve the prediction of outcomes and clinical decision-making for optimal follow-up.ROC curvesFeature Importance

Duration of sinus rhythm after direct current cardioversion does not predict recurrence of atrial fibrillation after subsequent catheter ablation: a multicentre study

Abstract Background Catheter ablation (CA) for persistent atrial fibrillation (PsAF) is associated with high rates of AF recurrence. DC cardioversion (DCCV) is often performed before CA, with wide variation in duration of maintenance of sinus rhythm (SR) post-DCCV. Factors associated with short duration of SR after DCCV, such as raised body mass index, prior duration of AF, prolonged p wave duration on the 12-lead ECG, and indexed left atrial volume, are either associated with or indicative of atrial electrical and structural remodelling, suggesting that shorter duration of SR after DCCV reflects a more advanced substrate for AF, which could in turn also influence the likelihood of success after CA. Objective To determine if post-DCCV SR duration is associated with AF recurrence after subsequent CA. Methods We performed a multicentre retrospective study of patients undergoing first-time CA for PsAF between 2015-2018 with prior DCCV. SR duration after the last DCCV prior to CA was recorded. The primary outcome was the first recurrence of atrial arrhythmia post-CA (after a 90-day post-CA blanking period). We also performed a pre-specified sensitivity analysis for amiodarone use at DCCV, by performing repeat analysis after excluding all such patients across the three groups. Results A total of 331 patients were identified across five centres and categorised by post-DCCV SR duration: <7 days (group 1); 7-31 days (group 2); >31 days (group 3; Table 1). Over median post-CA follow-up of 591 days, 207 patients (62.5%) met the primary outcome. There was no significant between-group difference in the time to primary outcome (log rank p=0.82; Figure 1). There were significantly more blanking period arrhythmias in groups 1 and 2 than group 3 after post hoc Bonferroni correction (pairwise p=0.001, 0.002 respectively; Table 1). After exclusion of patients on amiodarone at time of DCCV, there remained no significant between-group difference in the time to primary outcome (log rank p=0.85). Conclusion Shorter duration of SR post-DCCV is associated with blanking period arrhythmia after CA, but crucially does not predict long-term AF recurrence. Early AF recurrence after DCCV should not influence decisions on CA suitability or be used to predict long-term CA success.

Predictive value of the left atrioventricular coupling index for recurrence after radiofrequency ablation of paroxysmal atrial fibrillation

BackgroundAlthough patients with paroxysmal atrial fibrillation (PAF) are preferred to undergo catheter ablation (CA), the high possibility of recurrence following surgery is still concerning. We aimed to evaluate the ability of the left atrioventricular coupling index (LACI), which is the ratio of the left atrium end-diastolic volume to the left ventricle end-diastolic volume, to predict PAF recurrence after CA.MethodsPatients with PAF undergoing CA for the first time between January 2018 and June 2021 were admitted and grouped by recurrence within a year. LACI was measured before CA using ultrasonography. Risk factors identified by multivariable logistic regression analysis, and the area under the receiver operating characteristic (ROC) curve was used to assess the ability of LACI to predict PAF recurrence after CAP.ResultsAmong the 204 patients treated at our hospital, 164 patients were included in the research after eliminating those who were lost to follow-up. Among them, 56 individuals had recurrence following a 90-day blanking period. Recurrence is more likely in elderly patients with high blood pressure. Patients who suffered recurrence exhibited lower left atrial ejection fraction and increased LACI, left atrial volume minimum, and left atrium volume index maximum. LACI was an independent risk factor for postoperative recurrence (OR: 1.526, 95% CI: 1.325–1.757, P < 0.001), and ROC displayed remarkable predictive value [area under the curve (AUC) = 0.868].ConclusionsHigh LACI is significantly associated with postoperative recurrence in PAF patients, and LACI has incremental prognostic value to predict recurrence.

Mapping-Guided Ablation for Persistent Atrial Fibrillation (MAP-AF): A Multicenter, Single-Blind, Randomized Controlled Trial.

The clinical outcome of pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) is suboptimal. Mapping studies have demonstrated atrial sites outside of the pulmonary veins displaying focal activation patterns during AF. We sought to determine whether adding catheter ablation of focal activation sites to PVI improves clinical outcomes of catheter ablation for persistent AF. In this multicenter, randomized, single-blinded trial, we assigned patients with persistent AF to either PVI alone or to mapping-guided ablation of focal activation sites in addition to PVI in a 1:1 ratio. In the mapping-guided group, both atria were mapped after PVI using a Pentaray catheter (Biosense-Webster) and focal activation sites identified by CARTOFINDER (Biosense-Webster) were ablated. The primary end point was freedom from AF or atrial tachycardia without antiarrhythmic drugs beyond a 90-day blanking period. A total of 98 patients were assigned to the mapping-guided group and 102 to the PVI alone group. In the mapping-guided group, focal activation sites were identified at 2.6±0.3 and 2.5±0.2 sites per patient in the left and right atrium, respectively. Patients were followed up for 768.5 (interquartile range, 723.75-915.75) and 755.5 days (interquartile range, 728.5-913.75) in the mapping-guided ablation and the PVI alone groups, respectively. Freedom from AF/atrial tachycardia without antiarrhythmic drugs at 2-year follow-up was 66.8% and 75.2% in the mapping-guided ablation and the PVI alone groups, respectively (hazard ratio, 1.26 [95% CI, 0.76-2.10]; P=0.37). Adverse events occurred in 3 patients (3.0%) and none (0%) in the mapping-guided ablation and the PVI alone groups, respectively (P=0.12). In patients with persistent AF, the addition of mapping-guided ablation of focal activation sites to PVI did not improve clinical outcomes compared with PVI alone. URL: https://center6.umin.ac.jp/cgi-open-bin/ctr/index.cgi?function=02; Unique identifier: UMIN000037569.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry) - Clinical Impact of Early Recurrence.

Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.Methods and Results: Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62). ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

Real-world evidence demonstrates an appropriate atrial fibrillation population for hybrid convergent approach versus stand-alone cryoballoon ablation: A long-term safety and efficacy study.

A hybrid convergent approach (endocardial and epicardial ablation) demonstrated superior effectiveness in a recent randomized study for long-standing persistent atrial fibrillation (LSPAF). Yet, there is a lack of real-world, long-term evidence as to which patients are best candidates for a hybrid convergent approach compared to standard endocardial cryoballoon pulmonary vein isolation (CB PVI). This single-center, retrospective analysis spanning from 2010 to 2015 compared two distinctly different atrial fibrillation (AF) cohorts; one treated with stand-alone cryoablation and one treated with a hybrid convergent approach. Baseline characteristics described candidates for each approach. The following criteria were utilized to determine CB PVI candidacy: (1) paroxysmal AF (PAF) (stage 3A) with failed class I/III antiarrhythmic drug (AAD) or (2) persistent/LSPAF (stage 3B/3C/3D) with failed class I/III AAD unwilling to undergo hybrid procedure. Selection criteria for the hybrid procedure included: (1) PAF refractory to both class I/III AAD and prior CB PVI (stage 3D) or (2) persistent/LSPAF (stage 3B/3C/3D) with failed class I/III AAD agreeable to hybrid procedure. Prior sternotomy was excluded. Serial electrocardiograms and continuous monitoring evaluated primary efficacy outcome of time-to-first recurrence of atrial arrhythmia after a 90-day blanking period. Secondary outcomes were procedure-related complications and AAD use (at discharge, 12, and 36 months). Kaplan-Meier methods evaluated arrhythmia recurrence. Of 276 patients, 197 (64.2 ± 10.6 years old; 66.5% male; 74.1% 3A-PAF; 18.3% 3B/3D-persistent AF; 1.0% 3C-LSPAF; 6.6% undetermined) underwent CB PVI and 79 (61.4 ± 8.1 years old; 83.5% male; 41.8% 3D-PAF; 45.5% 3B/3D-persistent AF; 12.7% 3C/3D-LSPAF) underwent hybrid procedure. Arrhythmia freedom through 36 months was 55.2% for CB PVI and 50.4% for hybrid (p = .32). Class I AAD utilization at discharge occurred in 38 (19.3%) patients in the CB PVI group and 5 (6.3%) patients in the hybrid group (p = .01). CB PVI class I AAD utilization at 12 months occurred in 14 (9.0) patients versus 0 patients for hybrid convergent (p = .004). Patients with one or more adverse event were as follows: two (1.0%) in the CB PVI group (both transient phrenic nerve palsy) and three (3.7%) in the hybrid group (two with significant bleeding and one with wound infection) (p = .14). This study demonstrated that patients with more complex forms of AF (3D-PAF or 3B/3C/3D-persistent/LSPAF) could be well managed with a convergent approach. In a real-world evaluation, outcomes match safety and efficacy thresholds achieved for patients with earlier, less complex AF etiologies treated by CB PVI alone.

Long-term clinical impact of early recurrence of atrial tachyarrhythmia after cryoballoon ablation in patients with atrial fibrillation.

The impact of early recurrence of atrial tachyarrhythmia (ERAT) within the 90-day blanking period on long-term outcomes in atrial fibrillation (AF) patients undergoing cryoballoon ablation (CBA) is controversial. This study aimed to assess the relationship between ERAT and late recurrence of atrial tachyarrhythmia (LRAT) post-CBA. Utilizing data from a multicenter registry in Korea (May 2018 to June 2022), we analyzed the presence and timing of ERAT (<30, 30-60, and 60-90 days) and its association with LRAT risk after CBA. LRAT was defined as any recurrence of AF, atrial flutter, or atrial tachycardia lasting more than 30 s beyond the 90 days. Out of 2636 patients, 745 (28.2%) experienced ERAT post-CBA. Over an average follow-up period of 21.2 ± 10.3 months, LRAT was observed in 874 (33.1%) patients. Patients with ERAT had significantly lower 1-year LRAT freedom compared to those without ERAT (42.6% vs. 85.5%, p < .001). Multivariate analysis identified ERAT as a potential predictor of LRAT, with a hazard ratio (HR) of 3.98 (95% confidence interval [CI], 3.47-4.57). Significant associations were noted across all examined time frames (HR, 3.84; 95% CI, 3.32-4.45 in <30 days, HR, 5.53; 95% CI, 4.13-7.42 in 30-60 days, and HR, 4.29; 95% CI, 3.12-5.89 in 60-90 days). This finding was consistently observed across all types of AF. ERAT during the 90-day blanking period strongly predicts LRAT in AF patients undergoing CBA, indicating a need to reconsider the clinical significance of this period.

Initial real-world data on catheter ablation in patients with persistent atrial fibrillation using the novel lattice-tip focal pulsed-field ablation catheter.

Technological advancements have contributed to the enhanced precision and lesion flexibility in pulsed-field ablation (PFA) by integrating a three-dimensional mapping system combined with a point-by-point ablation strategy. Data regarding the feasibility of this technology remain limited to some clinical trials. This study aims to elucidate initial real-world data on catheter ablation utilizing a lattice-tip focal PFA/radiofrequency ablation (RFA) catheter in patients with persistent atrial fibrillation (AF). Consecutive patients who underwent catheter ablation for persistent AF via the lattice-tip PFA/RFA catheter were enrolled. We evaluated acute procedural data including periprocedural data as well as the clinical follow-up within a 90-day blanking period. In total, 28 patients with persistent AF underwent AF ablation either under general anaesthesia (n = 6) or deep sedation (n = 22). In all patients, pulmonary vein isolation was successfully achieved. Additional linear ablations were conducted in 21 patients (78%) with a combination of successful anterior line (n = 13, 46%) and roof line (n = 19, 68%). The median procedural and fluoroscopic times were 97 (interquartile range, IQR: 80-114) min and 8.5 (IQR: 7.2-9.5) min, respectively. A total of 27 patients (96%) were interviewed during the follow-up within the blanking period, and early recurrent AF was documented in four patients (15%) including one case of recurrent AF during the hospital stay. Neither major nor minor procedural complication occurred. In terms of real-world data, our data confirmed AF ablation feasibility utilizing the lattice-tip focal PFA/RFA catheter in patients with persistent AF.

Prevalence, timing, and impact of early recurrence of atrial tachyarrhythmias after pulsed field ablation: A secondary analysis of the PULSED AF trial

BackgroundEarly recurrence of atrial tachyarrhythmias (ERAT) within 3 months of thermal ablation for atrial fibrillation (AF) is common and often considered transient. Pulsed field ablation (PFA) is a nonthermal energy source in which ERAT is not well described. ObjectiveThe purpose of this study was to analyze ERAT in patients with AF undergoing PFA in the Pulsed Field Ablation to Irreversibly Electroporate Tissue and Treat AF (PULSED AF) trial. MethodsThis analysis included 154 (52.4%) paroxysmal AF and 140 (47.6%) persistent AF who had ≥10 rhythm assessments during the 90-day blanking period. ERAT was defined as any instance of ≥30 seconds of AF, atrial flutter, or atrial tachycardia on transtelephonic monitoring (weekly and symptomatic) or ≥10 seconds on electrocardiography (at 3 months), both within 90 days. Late recurrence of atrial tachyarrhythmias (LRAT) was defined as observed atrial tachyarrhythmias between 90 days and 12 months. ResultsThe overall prevalence of ERAT was 27.1% in patients with paroxysmal AF and 31.6% in patients with persistent AF. In patients with ERAT, 73% had ERAT onset within the first month of the procedure. The presence of ERAT was associated with LRAT in patients with paroxysmal AF (hazard ratio 6.4; 95% confidence interval 3.6–11.3) and patients with persistent AF (hazard ratio 3.8; 95% confidence interval 2.2–6.6). Yet, in 29.4% of patients with paroxysmal AF and 34.3% of patients with persistent AF with ERAT, LRAT was not observed. LRAT was positively correlated with the number of ERAT observations. ConclusionERAT after PFA predicted LRAT in patients with paroxysmal and persistent AF. However, the concept of a blanking period after PFA is still valid, as approximately one-third of patients with ERAT did not continue to have LRAT during follow-up and may not need reablation.

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

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

Impact of pulmonary vein variant anatomy during cryo-ablation in paroxysmal and persistent AF patients: 1-year outcome from a nationwide multicenter clinical setting

Abstract Background Complete electrical pulmonary vein isolation (PVI) by cryo-balloon approach is a well-established ablation strategy of atrial fibrillation (AF). While contrast findings exist regarding the influence of variant pulmonary vein (PV) anatomy on predicting AF recurrence, limited data are currently available specifically for cases involving the POLARx cryoablation system during PVI. Purpose We report the real-world experience of POLARx in the context of de novo AF ablation in a multicenter Italian registry. Methods Consecutive patients undergoing AF ablation from the CHARISMA registry at 10 Italian centres were included. Protocol-directed cryoablation was delivered for 180 sec or 240 sec according to operator’s preference for isolation achieved in ≤60 sec, or 240 sec if isolation occurred &amp;gt;60 sec or when time to isolation was not available. The ablation endpoint was PVI as assessed by entrance and exit block. All patients were followed-up for at least 12 months after the procedure. Results Four-hundred twenty-nine patients were included (n=358, 83.4% paroxysmal AF, n=71, 16.6% persistent AF, mean age 60.7±10 years, 28.3% female, mean LVEF 58±8%). PVI was achieved in all pts using only cryoablation. Twenty-eight (6.6%) patients exhibited an anatomical variant: 17 (4.0%) a common ostium and 11 (2.6%) an adjunctive PV. The mean number of freeze applications per patient was 5.1 (1.2 for LSPV, 1.3 for LIPV, 1.2 for RSPV and 1.3 for RIPV). Over a median of 398[370-461] days of follow-up, 14 (3.2%) patients experienced an early recurrence of AF during the 90-day blanking period. Overall, 63 patients (14.7%) suffered an AF recurrence after the 90-day blanking period (median time to recurrence 342[171-381] days). The proportion of patients exhibiting AF/AT recurrences was higher in the persistent AF group (17 out 71, 23.9%) than in the paroxysmal AF group (46 out 358, 12.8%, p=0.026), with a hazard ratio of 2.02 (95%CI: 1.2 to 3.5, p=0.0137) whereas patients with anatomy variant showed a similar AF/AT recurrence rate (5 out 28, 17.9%) than in the standard anatomy group (58 out of 401, 14.5%) with a hazard ratio of 1.43 (0.6 to 3.6, p=0.441). Four (0.9%) transient phrenic nerve palsy were observed, both with full recovery in the 48-h post procedure; no major procedure-related adverse events were reported. Conclusion In this multicenter study, the cryo-balloon system demonstrated safety and efficacy in treating both paroxysmal and persistent AF patients, yielding a low incidence of AF/AT recurrence during follow-up, regardless of the presence of variant PV anatomy.

Impact of early recurrences on late recurrences after pulmonary vein isolation with pulsed field ablation. A subanalysis from the EU-PORIA multicenter international registry

Abstract Background Early recurrences of atrial tachyarrhythmia (ERAT) are commonly observed after pulmonary vein isolation (PVI) with thermal energies. ERAT during the 90-day blanking period (BP) should not be considered therapy failure as the cardiac tissue is still healing and the long-term benefit of PVI may not be immediately apparent. With the introduction of pulsed field ablation (PFA), a non thermal, myocardial-specific ablation technology for atrial fibrillation (AF), the significance of ERAT following PVI is unclear. Methods EU-PORIA (EUropean real-world outcomes with Pulsed field ablatiOn in patients with symptomatic atRIAl fibrillation), a multicentre international registry, collected data from 1233 patients treated with the pentaspline PFA catheter. For the current analysis, patients with a previous AF ablation procedure, patients treated with lesions beyond PVI, and patients without complete follow up data (during and following the BP) were excluded. The rate and significance of ERAT following PFA PVI were analysed. Results This subanalysis included 1011 patients (38% female, 66±11 years old, 64% paroxysmal atrial fibrillation [PAF]). ERATs were recorded in 178/1011 (18%) of patients (16% in PAF and 21% in persAF, p=0,021). Notably, ERAT patients were older (67,1±11,4 Vs 65,4±10,9, p=0,015) and had a higher median CHA2DS2-VASc Score (2,5 [IQR:1-4] Vs 2 [IQR:1-3]; p=0,019). The 35-mm catheter was more often used in ERAT patients (48/178(27%) Vs 148/833(18%) – p=0,005). At a median follow-up of 365 days (IQR 347-390), 100/178(56%) of patients with ERAT had documented late recurrence (LR), compared to only 147/833(18%) of patients in sinus rhythm throughout BP (p&amp;lt;0,001). Kaplan Meier estimates for overall freedom from AF/AT outside of the BP was 77% at one year for all patients. Patients with ERAT had a significantly lower freedom from AF/AT compared to patients with no ERAT (42% vs 84%, log-rank p&amp;lt;0,001). The absence of ERAT was associated with long-term success independent of the type of AF (41% Vs 88% in PAF, 43% vs 74% in persistent AF; p&amp;lt;0,001 for both). Among ERAT patients, no additional predictors for LR were identified. Conclusions In this large multicentre international registry, early recurrence of atrial tachyarrhythmia following PFA PVI were recorded in 18% of patients. ERAT was associated with late recurrences in the majority of cases, independent of AF type. The need for a blanking period following non thermal energy ablation for atrial fibrillation should be further questioned.

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.

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

Comparison of pulsed field and radiofrequency ablation for non-paroxysmal atrial fibrillation: a propensity score-matched analysis

Abstract Background Ablation of non-paroxysmal atrial fibrillation (AF) is challenging and often requires left atrial substrate ablation. While the pentaspline, multi-electrode pulsed-field ablation (PFA) catheter is approved for pulmonary vein isolation (PVI), its role in procedures involving substrate ablation for nonparoxysmal forms of AF remains unknown. Purpose We conducted a retrospective study to assess the safety and long-term outcomes of PFA for non-paroxysmal AF. Methods Procedural and follow-up data were retrospectively collected for all patients undergoing a first-time ablation for non-paroxysmal AF across two centers, between November 2021 and December 2022. Patients undergoing PFA consisting of PVI, isolation of the posterior wall (PWI) and ablation of the mitral isthmus (MI) with the pentaspline multi-electrode PFA catheter, were compared with patients undergoing radiofrequency ablation (RFA) involving PVI, a roof line or PWI, alcohol ablation of the vein of Marshal (VOM) and MI ablation. Patients were matched using propensity scores to minimize potential confounders. The primary endpoint was arrhythmia (AF/atrial flutter/atrial tachycardia) recurrence after a 90-day blanking period. Results The baseline characteristics of the 116 matched patients are detailed in Table 1. PVI was successful in all patients. In the PFA group, PWI was additionally performed in all patients and MI ablation in 83% of cases, resulting in acute success rates of 97% and 96%, respectively. In the RFA group lesions beyond PVI included: a roof line (90%), PWI (10%), VOM alcohol ablation (93%) and MI ablation with ablation in the coronary sinus (CS) if needed (97%). Procedural block across the roof and the MI was achieved in 96% and 95%, respectively and complete PWI in 83% of cases. The PFA group had a shorter total procedure (84.2±22.3 vs 117.3±24.8 min, p&amp;lt;0.001) but a longer fluoroscopy time (23.1±7.2 vs 16.8±6.3 min, p&amp;lt;0.001). The difference in radiation dose, however, was not statistically significant (57.7±74.1 Gy.cm2 in the PFA vs 49.8±53.6 Gy.cm2 in the RFA group, p=0.24). The overall periprocedural complication rates were similar in both groups (8.6% PFA vs 12.1% RFA, p=0.76), with no cardiac tamponades or deaths. Group-specific complications included 1 coronary spasm in the PFA group and 1 CS dissection in the RFA group. During a median follow-up of 447 days (IQR: 364-552), 1 stroke occurred in each group and 1 sudden cardiac death in the RFA group, 13 months post-procedure. Both groups had similar rates of recurrences (32.8% PFA vs 25.9% RFA, p=0.54). Arrhythmia-free survival probability at 16 months was estimated at 67.2% for PFA and 77.6% for RFA by Kaplan-Meier analysis (p=0.16, Figure 1). Conclusions In this propensity-matched cohort of patients with non-paroxysmal AF, PFA and RFA demonstrated similar complication rates and arrhythmia-free survival at follow-up. The procedure duration, however, was significantly shorter with PFA.Figure 1

Impact of age on atrial arrhythmia recurrence following cryoballoon pulmonary-vein isolation

Abstract Background Age is a major risk factor for development of atrial fibrillation (AF) and associated with increased recurrence rates in the setting of rhythm control. Current data tend to support catheter ablation in elderly patients, but it remains unclear whether there is an age limit for ablation and whether the potential benefits of catheter ablation justify the potentially increased complication rate in elderly. Objective To prospectively analyze the impact of age on efficacy and safety of cryoballoon ablation (CBA). Methods ; We prospectively analyzed consecutive patients who underwent CBA in a single-center cohort between 2018 and 2023. Patients were stratified by age (&amp;lt;75yrs versus ≥75yrs) and AF type. Primary efficacy endpoint was recurrence of atrial arrhythmia after 90-day blanking period. Linear and spline regression were used to assess the association between age and primary efficacy endpoint. Safety endpoints were death, stroke or procedure-related complications. Results 873 patients underwent CBA (525 paroxysmal, 348 persistent AF). Median follow-up was 18-months. At 1-year, primary efficacy endpoint occurred in 19.6% (71/363) of young (&amp;lt;75yrs) versus 27.8% (45/162) of elderly (≥75yrs) patients with paroxysmal AF (HR 0.62; 95%CI, 0.41-0.92; P=0.019; fig. 1A) and in 25.0% (57/228) of young versus 39.2% (47/120) of elderly patients with persistent AF (HR 0.57; 95%CI, 0.37-0.85; P=0.006; fig. 1B). A significant linear relationship between age and primary efficacy endpoint occurrence was found for both paroxysmal (P=0.01) and persistent AF (P=0.002; fig.2) while spline regression was non-significant (P=0.45/ P=0.12). No difference was observed regarding the incidence of safety endpoints between young and elderly patients (P=0.76). Conclusion Atrial arrhythmia recurrence rate after CBA increases linearly with age (thus not allowing determination of a clear "cut-off-age") and is highest in elderly patients (≥75 yrs) with persistent AF. Safety of CBA in elderly is comparable to patients of younger age.

Right atrial endomysial fibrosis is associated with higher POAF-burden

Abstract Background Atrial endomysial fibrosis, rather than overall connective tissue content, determines the complexity of conduction in human atrial fibrillation (AF). Moreover, the AF-specific blood biomarker BMP10 is associated with atrial endomysial fibrosis, but not overall connective tissue content. It is unclear whether pre-operative atrial endomysial fibrosis predicts post-operative AF (POAF) incidence and burden. Objective To determine the predictive value of atrial fibrosis for early and late POAF burden. Methods Patients with and without AF history were included in the RACE V tissue bank study (n=134). Post-operative rhythm was monitored continuously for 2.5 years with implantable loop recorders. Late POAF-burden was investigated following a 90-day blanking period. Left (n=89) and/or right (n=92) atrial appendage biopsies (LAA/RAA) were snap-frozen and histologically investigated following WGA-staining. Results Logistic regression, corrected for age, sex and AF history, showed that left (st.β = 0.54 [0.23-0.85], p=0.001) and right (st.β=0.35 [0.07-0.64], p=0.017) atrial endomysial fibrosis were associated with early POAF burden in the blanking period. Only right atrial endomysial fibrosis, however, predicted late POAF-burden (st.β=0.44 [-], p=0.009). Adjusted Cox proportional hazards analyses indicated that patients in the highest tertile of right atrial endomysial fibrosis, in particular, are at risk for late POAF (HR T3 vs T1: 2.47 [1.18-5.17], p=0.016, Fig 1). Overall connective tissue content in both atria was not associated with POAF-burden. Conclusion Patients with higher levels of right atrial endomysial fibrosis are at risk for developing late POAF with a higher POAF-burden.Figure 1