Blanking Period Research Articles

Ultra-short-term deceleration capacity and heart rate variability as indicators of vagal denervation before and after pulmonary vein isolation

Abstract Introduction Pulmonary vein isolation (PVI) is a well-established therapy of atrial fibrillation (AF). However, subtypes of AF can differ and exact mechanisms in which patients benefit from PVI remain not fully understood. Parasympathetic activity can play important role in pathogenesis of AF. Moreover, catheter ablation can impact vagal innervation of the heart, nevertheless methods of periprocedural assessment of such impact of PVI are lacking. Purpose Ultra-short-term deceleration capacity (UST-DC) and ultra-short-term heart rate variability (UST-HRV) were investigated to determine their potential function as indicators of parasympathetic activity before and after PVI. Methods 24 consecutive patients (8 females, age 54±11) with paroxysmal AF were included in the study. UST-DC and UST-HRV were calculated from 1-minute ECG recordings performed before and after PVI. Results There was a significant differences between UST-DC before PVI vs after PVI (7.6ms vs 2.8ms; p=0.0000018) and between UST-HRV parameters before and after PVI: standard deviation of normal-to-normal (UST-SDNN) (37.8ms vs 18.4ms; p=0.00005), root mean square of successive differences (UST-rMSSD) (25.3ms vs 12.2ms; p=0.00083) and proportion of success NN intervals differing more than 50ms divided by total number of NNs (UST-pNN50) (8.4% vs 2%; p=0.045). Heart rate (HR) increase was also statistically significant (pre-PVI vs post-PVI, 65.5bpm vs 73.7bpm; p=0.016). After 3-months patients with baseline UST-DC>7.5ms, were less likely to experience AF recurrence when compared to patients with baseline UST-DC<7.5ms (0% vs 31%, p=0.0496). In these groups difference in AF recurrences after 12-months of follow-up did not meet statistical significance (36% vs 38%, p=0.52). No correlation between UST-HRV parameters and AF recurrence during follow up was observed. Conclusions PVI leads to significant changes in UST-DC and UST-HRV and these parameters may serve as indicators of vagal denervation after AF ablation. Patients with more prominent baseline UST-DC are less likely to experience AF recurrence during 3-month blanking period after PVI.

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=<0.001 and 4.9 vs. 2.2 Gycm2, p=<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

An economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation from a Danish healthcare perspective

Abstract Background As demonstrated in three randomized clinical trials (RCTs), initial rhythm control with first-line pulmonary vein isolation (PVI) using cryoballoon ablation decreases atrial arrhythmia recurrence compared to antiarrhythmic drug (AAD) therapy in patients with symptomatic paroxysmal atrial fibrillation (PAF). Purpose To assess the cost-effectiveness of first-line cryoablation versus first-line AADs in a Danish healthcare setting. Methods Data from 703 participants with symptomatic PAF enrolled into Cryo-FIRST, STOP AF First and EARLY-AF RCTs were used to estimate risk equations (rate of ablation, AF recurrence and resolution, AF-related hospital attendance in addition to health-related quality-of-life (HRQoL) utilities). These were then incorporated into a cost-effectiveness model (CEM) . The Danish cost data was derived from published Danish literature, DRG tariffs and pharmaceutical list prices in Denmark. Where parameters could not be derived, inputs were sourced from published literature or expert opinion. The CEM consisted of a decision tree (one-year time horizon) and a Markov model (three-month cycle length) hybrid, with a lifetime (40 years) time horizon. The CEM is from the perspective of the Danish healthcare system. Health benefits were expressed in quality-adjusted life-years (QALYs), and all costs and benefits were discounted at 3%. As there is no official cost-effectiveness threshold in Denmark, the UK threshold of £20,000 (~€23,200) was assumed. Input uncertainty within the CEM was explored using probabilistic sensitivity analysis. The results presented include data from the initial 12-week blanking period for all studies. Results The three-monthly rate of AF symptom recurrence had a reduction, on average, of 46.7% (p<0.001) in those treated with cryoablation. In addition, the cryoablation arm had a 72.8% (p<0.001) reduction in the monthly rate of receiving an ablation following initial treatment. The average cryoablation patient was also associated with a 4.3% (p=0.025) increase in their HRQoL. Finally, there was no difference in the rate of AF symptom resolution in those who failed initial treatment. Base case results per patient are presented in Table 1. Cryoablation was shown to be dominant when compared to AADs (0.159 more QALYs and €2,519 less costly), with a 99.96% probability of being cost-effective at a willingness-to-pay threshold of ~€23,200 per QALY gained. Individuals in both arms of the model were also expected to receive ~1.2 ablations over a lifetime horizon. Nonetheless, there was a 45% relative reduction in time spent in symptomatic AF states for individuals who were initially treated with cryoablation. Scenario analysis results are presented in Table 2. Cryoablation remained cost-effective over AADs in all scenarios conducted. Conclusions Initial rhythm control with cryoballoon ablation is cost-effective (dominant) when compared to AADs in the Danish healthcare system.Table 1:Key results (per patient)Table 2.Deterministic scenario analysis

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.

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<0.001) but a longer fluoroscopy time (23.1±7.2 vs 16.8±6.3 min, p<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

The new "olive strategy" for pulsed field ablation of atrial fibrillation: procedural data and early follow-up

Abstract Background Pulsed field ablation (PFA) is a new myocardial-specific ablation technology for atrial fibrillation (AF). Direct current electric energy is applied to cells and disrupts cell membranes by creating pores. Purpose The aim of this single-center study was to report procedural data and early recurrence of atrial tachyarrhythmia (ERAT) following a new PFA-based ablation strategy for pulmonary vein isolation (PVI). Methods Consecutive patients with symptomatic AF were enrolled to undergo PFA-PVI using the pentaspline catheter. A new ablation strategy was performed: In total 10 applications per pulmonary vein (PV) were delivered. In addition to the conventional four applications in flower- and four applications in basket-configuration, two applications were delivered in a smaller "olive"-configuration. ERAT was defined as any documented AF/atrial tachycardia (AT) lasting more than 30 seconds during a 90-days blanking period. Procedural and demographic data were analysed. Results 60 patients (37% female, age 67±12, 43% paroxysmal atrial fibrillation [PAF]) were included in this preliminary analysis. 239 PVs were identified, and all PVs could be isolated using solely the PFA device. All PVs were isolated with the first application. 40 applications per patient were delivered. No complications occurred. Procedure time was 30±11 min, fluoroscopy time was 6±3 min. Median follow-up time was 100 days. 20% of patients experienced an early recurrence after a median of 2 days (IQR 1-7.25; 92% AF, 8% AT). Kaplan Meier estimated freedom of AF/AT was 83.3 % at 3 months, 92.3% for PAF and 76.5% for persistent atrial fibrillation (p=0.11). Conclusions Our data show feasibility of a new ablation strategy with the pentaspline PFA-catheter. This study indicates high acute efficacy and safety. 83.3% of patients are free of AF/AT at 3 months. Longer follow-up times are needed to assess the clinical outcome and will be available at the time of presentation.

Efficacy and safety of very high-power short-duration posterior wall ablation in persistent atrial fibrillation: a propensity score-matched comparison with standard power long-duration ablation

Abstract Background Catheter ablation (CA) with pulmonary vein isolation (PVI) is an optimal treatment option in patients with paroxysmal atrial fibrillation (AF). PVI alone in patients with persistent AF has proved to have suboptimal results. Ablation of additional atrial structures, such as posterior wall (PW) and left atrial appendage has been investigated as a tool to improve procedural efficacy. Recently very high-power short-duration (vHPSD) ablation was developed to allow rapid PVI, limiting complication through the maximization of resistive heating, and minimization of conductive heating. Objectives Compare PVI plus PWI using vHPSD versus standard-power (SP) ablation index-guided CA among consecutive patients with persistent AF Methods Forty consecutive patients underwent PVI plus PW isolation using vHPSD, compared to 40 controls underwent standard power (SP) PVI plus PW isolation. The primary efficacy endpoint outcome was recurrence of atrial tachyarrhythmias after a 3-month blanking period. The primary safety outcome was a composite of major complications within 30 days of CA. Results Treated patients have a median age of 62.8±9 years, 68 (85%) are male. Median left atrial volume is 42.4 (36-50) ml/m2. 61 (78.8%) patients had never undergone catheter ablation before. There are no statistically significant differences between groups. PW isolation was obtained more commonly in the vHPSD compared to the SP group (98% vs. 75%, p=0.007), despite shorter procedure and fluoroscopy times (p<0.001). Survival free from recurrent atrial tachyarrhythmias at 18 months was 68% in the vHPSD and 47% in SP groups, respectively (log-rank p=0.071), without major adverse events. The vHPSD approach was significantly associated with reduced risk of recurrent AF at multivariable analysis (HR, 0.39, p=0.030). Conclusions The results show feasibility and safety of posterior wall vHPSD ablation for persistent AF using this new temperature-controlled catheter without intraprocedural and periprocedural major complications at follow-up. vHPSD ablation for PW isolation may be more effective in term of atrial tachyarrhythmias recurrences with a trend for superior efficacy. However, this remains a single center experience in a small group of patients. Comparative trials involving greater number of patients with long-term follow-up are necessary to definitive results.

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 (<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 (<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.

Impact of obesity and pattern of atrial fibrillation on long-term outcome following cryoballoon pulmonary vein isolation

Abstract Background Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted method for treatment of paroxysmal and persistent atrial fibrillation (PAF, PeAF). Obese and PeAF patients do worse following ablation. However, there are limited data on the impact of both variables on outcomes. Objective To understand the impact of obesity and AF pattern on long-term outcomes following CB PVI. Methods We enrolled consecutive AF patients undergoing CB PVI; all patients had an implantable loop recorder (ILR) for long term continuous monitoring. Obesity (O) was defined as a BMI ≥ 30 kg/m2. The cohort was divided into 4 groups based on presence of obesity and type of AF at the initial ablation: (1) N-O (non-obese) and PAF, (2) O and PAF, (3) N-O and PeAF, and (4) O and PeAF. We assessed long-term AF recurrences, after excluding an initial 3-month post-ablation blanking period. Results The cohort included 322 patients (67 ± 9 years; 209 [65%] male; 177 [55%] PAF; CHA2DS2-VASc 2.7 ± 1.6, 137 [43%] O). Obese patients were younger and more likely to have hypertension and diabetes. During a follow-up of 931 ± 599 days, 211 (66%) patients had recurrent AF. The best outcome was seen in N-O obese patients with PAF; all other groups fared similarly (Figure). Group 1 had significantly lower AF recurrence compared to all 3 other groups (Figure). In multivariate analysis, obesity/AF type was the only significant predictor of AF recurrence (Table). As compared to N-O PAF pts, O PeAF patients had a 2-fold greater likelihood of AF recurrence. Conclusions During almost 3-years of objective follow-up, we found that CB PVI performs best in non-obese pts with PAF. Once obesity occurs, PAF pts respond as poorly to PVI as pts with PeAF, irrespective of obesity status. Additional strategies are needed in these patients.

Arrhythmia-induced versus arrhythmia-superimposed cardiomyopathy: outcome in patients with atrial fibrillation and heart failure undergoing cryoballoon pulmonary vein isolation

Abstract Introduction The outcome in patients with arrhythmia-induced cardiomyopathy (AIC) compared with that in patients with arrhythmia-mediated/superimposed cardiomyopathy (AMC) undergoing cryoballoon pulmonary vein isolation (cryo-PVI) is also poorly defined. Methods In this retrospective observational study, we analysed patients with AF and reduced left ventricular ejection fraction (LVEF < 50%) who underwent cryoballoon ablation between 2014 and 2020. Patients with LVSD were divided into AIC and AMC. AIC was diagnosed ex juvantibus during first year after ablation at 3- and 12-month follow-up when LVEF recovered to > 50% and by more than 10% after ablation and a different aetiology for reduced LVEF was excluded. AMC was diagnosed when structural heart disease was responsible for LVSD and AF had likely exacerbated pre-existing LVSD. For identification of independent predictors of LVEF non-improvement after ablation, univariate and multivariate logistic regression analyses were performed. LVEF non-improvement was defined when LVEF neither increased by more than 10% nor increased over absolute 50% at 12-month follow-up. The first documented > 30-s atrial arrhythmia recurrence after a 3-month blanking period during the one-year follow-up was compared by Kaplan-Meier analysis. Results Out of 1293 consecutive patients who underwent cryoballoon ablation, 113 AF patients with reduced LVEF (<50%) were identified. After 1-year follow-up these patients were divided into AIC (N= 77) and AMC (N = 36) groups. The prevalence of persistent AF was comparable in both groups (85.7% vs. 77.8 %, p = 0.435). LVEF, left atrial (LA) enlargement, and left ventricular end diastolic diameter (LVEDD) were similar between the groups. After one year, the median LVEF improved significantly in the AIC group from 42% (IQR: 35-45%) to 60% (IQR: 58-63%; p < 0.0001) and in the AMC group from 42% (IQR: 33-45%) to 47.5% (IQR= 43-53%; p=0.015). At follow-up LVEF was significantly higher in the AIC than in the AMC cohort (p < 0,001). After univariate and multivariate analysis, the following parameters were associated with non-LVEF improvement: LVEDD (OR = 1.12, p = 0.012) and atrial arrhythmia recurrence (OR = 5.87, p = 0.031; Figure 1). In the AIC group LA area decreased from 25.6 cm2 (IQR: 22.4-29.5 cm2) to 21.8 cm2 (IQR: 18.3-25.2 cm2; p = 0.012). In AMC patients LA enlargement did not change with respect to baseline. Kaplan-Meier curves demonstrated no difference in recurrence-free survival rate between the groups during the 12-month follow-up (75.3% vs. 75%, log-rank P = 0.89; Figure 2). Conclusions LVEDD and arrhythmia recurrence were identified as predictors of non-LVEF improvement after cryo-PVI. The LVEF increased in both groups after ablation, but in AIC group more than in AMC group. In the AIC group LA atrial area decreased compared to the AMC group. Atrial arrhythmia recurrence rates were comparable between AIC and AMC groups after 12 months.Figure 1Figure 2

Predictive value of guideline-referred risk scores in estimating left atrial low voltage areas and recurrence of atrial fibrillation in repeat ablation procedures

Abstract Background Despite advances in mapping and ablation techniques, atrial fibrillation (AF) recurrence remains a challenge after pulmonary vein isolation. Low voltage areas (LVA) in the left atrium are associated with higher recurrence rates after left atrial ablation. Risk scores for evaluating post-ablation recurrences are not well established, although a better patient selection for repeat procedures would be of great help in clinical practice. Purpose Risk scores for prediction of AF recurrence have not been tested in a cohort of repeat ablations. Methods This single-center study includes consecutive patients from the prospective Bernau ablation registry undergoing ultra-high-density (UHD) mapping and repeat ablation for AF/AT recurrence between 2016 and 2020. The potential of seven guideline mentioned risk scores (APPLE, DR-FLASH, MB-LATER, ATLAS, CAAP-AF, BASE-AF 2, ALARMEc) to predict (1) AF/AT recurrence beyond a three-months blanking period after repeat left atrial ablation (Re-PVI ± further LA ablation) and (2) the percentage of left atrial LVA in UHD mapping was investigated. LVA were defined as sites with a bipolar peak-to-peak voltage of <0.5 mV with an extent of >1cm². Optimal cutoff for sensitivity and specificity for LVA and AF/AT recurrence as endpoint was chosen using C statistics with receiver-operator characteristics (ROC). Further ROCs were performed to illustrate the predictive ability of the scores. Pearson correlation was used to test associations between variables. Results 160 patients (mean age 67.9 ± 9.1 years, 60.6% persistent AF, mean AF duration 4.6 ± 3.8 years) with complete left atrial UHD mappings (mean EGMs 9754 ± 5808) were included. Overall recurrence rate over a mean follow-up time of 16 ± 11 months was 55.6%. The predictive value of the investigated risk scores on AF/AT recurrence in our cohort was low (Table 1), with the highest power for CAAP-AF (p = 0.015, AUC = 0.615) and DR-FLASH score (p = 0.040, AUC = 0.594), Figure 1. With respect to left atrial LVA we found a better predictive power for the CAAP-AF (p < 0.001, AUC 0.702), APPLE (p < 0.001, AUC 0.687), DR-FLASH (p < 0.001, AUC 0.688), ATLAS (p = 0.005, AUC 0.634) and ALARMEc (p = 0.007, AUC 0.608) score to predict low voltage based on a calculated cut-off of 22% of total left atrial surface (Figure 1). Conclusion The predictive value of guideline-referred risk scores in estimating AF/AT recurrence after repeat ablation is low and does not seem to be of relevant help in patient selection for further interventional treatment. Some scores demonstrate a fairly good prediction for the amount of left atrial LVA and therefore might help in choosing the right mapping and ablation regime beforehand.

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 >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.

The impact of cardiac rehabilitation on atrial fibrillation recurrence after pulmonary vein isolation: results of a retrospective study

Abstract Background Although pulmonary vein isolation (PVI) is an extensively utilized atrial fibrillation (AF) treatment, many patients still experience AF recurrences. Multimorbidity care, including physical activity, may reduce recurrences. In Belgium, patients undergoing an ablation are entitled to a cardiac rehabilitation (CR) program after PVI, but not all do participate. More evidence that such (standardized) CR programs for AF patients after ablation can positively impact rhythm control is desirable. Purpose This study retrospectively investigated the impact of CR on AF recurrence after PVI. Methods We analysed an extensive database of a large Belgian tertiary care center with patients who underwent a primary PVI between 2007 and 2020 and who had a follow-up of at least 1 year. General cardiology follow-up included a 24h Holter monitoring 3 and 12 months after PVI. Patients were retrospectively divided into an intervention and control group based on their choice to participate in a standardized CR program. The Kaplan-Meier method was used to estimate the time-to-recurrence and event-free survival curves after the primary ablation. Differences between curves were tested with the log-rank test. Mann-Whitney U test was used to analyze continuous variables and the Chi-square test for categorical variables. Results In total, 1767 patients were included, of which 589 participated to CR and 1178 served as controls (median 64 (56-70) y, 68.9% male, median BMI 27.5 (24.7-30.7) kg/m2). There was no significant difference between CR and controls in median age (64y vs. 63y respectively; p=0.203), the proportion of male (57.9% vs. 47.0% respectively; p=0.111) and the proportion of paroxysmal AF (66.4% vs. 70.6% respectively; p=0.210). The proportion with recurrent AF at the end of study follow-up (with a three-month initial blanking period) in the CR and control group was similar (32.6% vs. 35.1% respectively; p=0.288), and also survival analysis demonstrated no significant difference (p=0.827; Figure 1). We noted a cross-over of the recurrence curves after about 1500 days, but the rate of AF recurrence was not different among CR and controls within the first year post-ablation (p=0.136) nor when analysed from day 365 until the end of the study (p=0.341) (Figure 2). There was no significant difference in AF recurrences between CR and controls for either paroxysmal AF (p= 0.551) or persistent AF (p=0.181) based on the survival analysis. Conclusions This retrospective analysis could not demonstrate reduced AF recurrence in post-PVI patients following a structured CR program. The unexpected crossover of curves could point to earlier AF detection in CR patients, while there might be long-term benefit of physical activity. Multivariable analysis will have to evaluate whether impact of CR is related to certain clinical patient characteristics, which might also have contributed to inclusion bias.Figure 1Figure 2

Dual-energy lattice-tip ablation system for persistent atrial fibrillation: a randomized trial

Clinical outcomes of catheter ablation for atrial fibrillation (AF) are suboptimal due, in part, to challenges in achieving durable lesions. Although focal point-by-point ablation allows for the creation of any required lesion set, this strategy necessitates the generation of contiguous lesions without gaps. A large-tip catheter, capable of creating wide-footprint ablation lesions, may increase ablation effectiveness and efficiency. In a randomized, single-blind, non-inferiority trial, 420 patients with persistent AF underwent ablation using a large-tip catheter with dual pulsed field and radiofrequency energies versus ablation using a conventional radiofrequency ablation system. The primary composite effectiveness endpoint was evaluated through 1 year and included freedom from acute procedural failure and repeat ablation at any time, plus arrhythmia recurrence, drug initiation or escalation or cardioversion after a 3-month blanking period. The primary safety endpoint was freedom from a composite of serious procedure-related or device-related adverse events. The primary effectiveness endpoint was observed for 73.8% and 65.8% of patients in the investigational and control arms, respectively (P < 0.0001 for non-inferiority). Major procedural or device-related complications occurred in three patients in the investigational arm and in two patients in the control arm (P < 0.0001 for non-inferiority). In a secondary analysis, procedural times were shorter in the investigational arm as compared to the control arm (P < 0.0001). These results demonstrate non-inferior safety and effectiveness of the dual-energy catheter for the treatment of persistent AF. Future large-scale studies are needed to gather real-world evidence on the impact of the focal dual-energy lattice catheter on the broader population of patients with AF. ClinicalTrials.gov identifier: NCT05120193.

Recurrences after Pulsed Field Ablation of Atrial Fibrillation: Incidence, Mechanisms, Predictors, and Comparison with Thermal Energy

Pulsed Field Ablation (PFA) is the latest and most intriguing technology for catheter ablation of atrial fibrillation, due to its capability to generate irreversible and cardiomyocytes-selective electroporation of cell membranes by delivering microsecond-lasting high-voltage electrical fields, leading to high expectations. The first trials to assess the clinical success of PFA, reported an arrhythmia-free survival at 1-year of 78.5%, while other trials showed less enthusiastic results: 66.2% in paroxysmal and 55.1% in persistent AF. Nevertheless, real world data are encouraging. The isolation of pulmonary veins with PFA is easily achieved with 100% acute success. Systematic invasive remapping showed a high prevalence of durable pulmonary vein isolation at 75 and 90 days (range 84–96%), which were significatively lower in redo procedures (64.3%). The advent of PFA is prompting a reconsideration of the role of the autonomic nervous system in AF ablation, as PFA-related sparing of the ganglionated plexi could lead to the still undetermined effect on late arrhythmias’ recurrences. Moreover, a new concept of a blanking period could be formulated with PFA, according to its different mechanism of myocardial injury, with less inflammation and less chronic fibrosis. Finally, in this review, we also compare PFA with thermal energy.

Effects of Glucagon-Like Peptide-1 Receptor Agonists on Atrial Fibrillation Recurrence After Catheter Ablation

BackgroundRelationship between glucagon-like peptide-1 receptor agonist (GLP-1 RA) use prior to atrial fibrillation (AF) ablation and subsequent AF recurrence is not well-understood. ObjectivesThis study investigated the effects of GLP-1 RA use within 1 year before ablation and its association with AF recurrence and associated outcomes. MethodsThe TriNetX research database was used to identify patients aged ≥18 years undergoing AF ablation (2014-2023). Patients were categorized into 2 groups, and propensity score matching (1:1) between preablation GLP-1 RA users and nonusers was performed based on demographics, comorbidities, body mass index, laboratory tests, AF subtype, and medications. Primary outcome was composite of cardioversion, new antiarrhythmic drug therapy, or repeat AF ablation after a 3-month blanking period following the index ablation. Additional outcomes included ischemic stroke, all-cause hospitalization, and mortality during 12-month follow-up period. ResultsAfter 1:1 propensity score matching, the study cohort comprised 1,625 GLP-1 RA users and 1,625 matched GLP-1 RA nonusers. Preablation GLP-1 RA therapy was not associated with a lower risk of cardioversion, new AAD therapy, and repeat AF ablation after the index procedure (HR: 1.04 [95% CI: 0.92-1.19]; log-rank P = 0.51). Furthermore, the risk of ischemic stroke, all-cause hospitalization, and mortality during the 12-month follow-up period did not differ between the 2 groups. ConclusionsThese findings suggest that preprocedural use of GLP-1 RAs is not associated with a reduced risk of AF recurrence or associated adverse outcomes following ablation, and underscore the need for future research to determine whether these agents improve outcome in AF patients.

Efficacy of Shensong Yangxin capsule combined with dronedarone in paroxysmal atrial fibrillation after ablation.

To investigate whether postoperative administration of Shensong Yangxin capsules (SSYX) and dronedarone for atrial fibrillation (AF) can reduce the recurrence of paroxysmal AF after radiofrequency ablation, thus providing a more optimal choice of antiarrhythmic medication during the blank period. We included 120 patients with paroxysmal AF who underwent radiofrequency ablation at our hospital between July 2020 and July 2022. They underwent routine circumferential pulmonary vein ablation and, subsequently, left and right atrial pressure monitoring to assess sinoatrial node recovery time under burst 400/300 ms stimulation. Postoperatively, the patients were randomly divided into 2 groups (60 patients each). The control group was administered dronedarone orally for 3 months and the study group was treated with SSYX combined with dronedarone. This study aimed to compare differences in clinical efficacy of the treatment between the 2 groups. The left and right atrial pressures in both groups were higher than those in the preoperative period (P < .05), with no statistically significant differences between the 2 groups (P > .05). Sinoatrial node recovery time under burst 400/300 ms stimulation showed no statistical difference between the 2 groups (P > .05). At 3 months and 1 year postoperatively, the AFEQT scale scores for both groups were lower than those before treatment (P < .05), with the study group scoring lower than the control group at 3 months (P < .05). However, no statistically significant difference was observed between the 2 groups at 1 year postoperatively (P > .05). At 3 months postoperatively, the sinus rhythm maintenance rate and heart rate were higher in the intervention group than in the control group (P < .05); however, these differences between the 2 groups were not statistically significant at 1 year postoperatively (P > .05). The combination of SSYX and dronedarone could effectively reduce the early recurrence of paroxysmal AF after radiofrequency ablation, increase heart rate, and improve the quality of life.

Repeat cryoablation as a redo procedure for atrial fibrillation ablation: Is it a good choice?

Ablation of atrial fibrillation (AF), both cryoablation ablation (CBA) and radiofrequency catheter ablation (RFCA), have demonstrated to be safe and effective. About 1 in 3 patients may face a redo due to recurrence and the best technique is unknown. The aim of this study is to assess the efficacy of CBA as a repeat procedure in patients with prior CBA or RFCA. A nation-wide CBA registry (RECABA) was analyzed and patients were compared who had previously undergone CBA (Prior-CB) or RFCA (Prior-RF). The primary endpoint was AF recurrence at 12 months after a 3-month blanking period. A survival analysis was performed, univariate and multivariate Cox models were also built. Seventy-four patients were included. Thirty-three (44.6%) were in the Prior-CB group and 41 (55.4%) in the Prior-RF. There were more reconnected pulmonary veins in the Prior-RF than in Prior-CB group (40.4% vs.16.5%, p = 0.0001). The 12-month Kaplan-Meier estimate of freedom from AF recurrence after the blanking period was 61.0% (95% confidence interval [CI] 41.4-75.8%) in the Prior-CB, and 89.2% (95% CI 73.6-95.9%) in the Prior-RF group (p = 0.002). Multivariate Cox regression pointed Prior-CB as the sole independent predictor of AF recurrence, with an adjusted HR of 2.67 (95% CI 1.05-6.79). Repeat CBA shows higher rates of AF recurrences compared to CBA after a previous RFCA despite presenting less reconnected veins at the procedure. These data suggest that patients with AF recurrence after CBA may benefit from other ablation techniques after a recurrence. RECABA is registered at clinicaltrials.gov with the Unique Identifier NCT02785991.

Posterior wall ablation for persistent atrial fibrillation: Very-high-power short-duration versus standard-power radiofrequency ablation

Posterior wall ablation (PWA) is commonly added to pulmonary vein isolation (PVI) during catheter ablation (CA) of persistent atrial fibrillation (AF). The purpose of this study was to compare PVI plus PWA using very-high-power short-duration (vHPSD) vs standard-power (SP) ablation index-guided CA among consecutive patients with persistent AF and to determine the voltage correlation between microbipolar and bipolar mapping in AF. We compared 40 patients undergoing PVI plus PWA using vHPSD to 40 controls receiving PVI plus PWA using SP. The primary efficacy endpoint was recurrence of atrial tachyarrhythmias after a 3-month blanking period. The primary safety outcome was a composite of major complications within 30 days after CA. In the vHPSD group, high-density mapping of the posterior wall was performed using both a multipolar catheter and microelectrodes on the tip of the ablation catheter. PVI was more commonly obtained with vHPSD compared to SP ablation (98%vs 75%; P = .007), despite shorter procedural and fluoroscopy times (P <.001). Survival free from recurrent atrial tachyarrhythmias at 18 months was 68% and 47% in the vHPSD and SP groups, respectively (log-rank P = .071), without major adverse events. The vHPSD approach was significantly associated with reduced risk of recurrent AF at multivariable analysis (hazard ratio 0.39; P = .030). Microbipolar voltage cutoffs of 0.71 and 1.69 mV predicted minimum bipolar values of 0.16 and 0.31 mV in AF, respectively, with accuracies of 0.67 and 0.88. vHPSD PWA plus PVI may be faster and as safe as SP CA among patients with persistent AF, with a trend for superior efficacy. Adapted voltage cutoffs should be used for identifying atrial low-voltage areas with microbipolar mapping.

Durability of CLOSE-Guided Pulmonary Vein Isolation in Persistent Atrial Fibrillation: A Prospective Remapping Study

BackgroundRecurrence of paroxysmal atrial fibrillation (AF) following pulmonary vein isolation (PVI) is presumably caused by pulmonary vein (PV) reconnections. However, there is little data available on the durability of PVI and incidence of arrhythmia recurrence in patients with persistent AF. ObjectivesThe purpose of this study was to evaluate the lesion durability by means of an a priori planned remapping procedure in patients with persistent AF undergoing CLOSE-guided PVI. MethodsIn a prospective study, we included patients with symptomatic, persistent AF undergoing CLOSE-guided radiofrequency ablation. Irrespective of AF recurrence, a redo procedure was mandated 6 months following the index procedure to evaluate PV reconnections. The outcome of AF ablation was based on clinical recurrence and 7-day Holter electrocardiogram 3 and 6 months after the index procedure and 3, 6, and 12 months after the redo procedure. ResultsOf 30 patients included, 26 (81% men; median age 68 years) underwent the planned remapping study a median of 6 months after the index procedure, whereas 4 patients without recurrence refused a repeat procedure. In total, 78 of 102 (76%) PVs showed durable isolation and 15 patients (58%) presented complete isolation of all PVs. Beyond the blanking period, 6 of 26 patients (23%) had arrhythmia recurrence before the redo procedure. Recurrence had occurred in 33% of patients with complete isolation of all veins and in 9% of patients with PV reconnections (P = 0.197). After re-PVI in patients with PV reconnections and additional ablation in patients with recurrence but durable PVI, 17 of 26 patients (65%) were free of arrhythmia after 12 months. ConclusionsIn patients with persistent AF, CLOSE-guided PVI resulted in durable rate of PVI on a per-vein and per-patient level of 76% and 58%, respectively. Arrhythmia recurrence was numerically higher in patients with durable PVI compared with patients without.