90-day Blanking Period Research Articles

Pulsed-field vs cryoballoon vs radiofrequency ablation: Outcomes after pulmonary vein isolation in patients with persistent atrial fibrillation

BackgroundPulsed-field ablation (PFA) has shown promising data in terms of safety and procedural efficiency for pulmonary vein isolation (PVI), with similar long-term outcomes compared to radiofrequency ablation (RFA) and cryoballoon ablation (CBA) in patients with paroxysmal atrial fibrillation (AF). ObjectiveThe purpose of this study was to compare the procedural and long-term outcomes in patients with persistent AF undergoing PVI using PFA, CBA, or RFA. MethodsConsecutive patients with persistent AF undergoing first PVI with PFA, CBA, or RFA were included. Patients underwent 7-day Holter electrocardiography at 3, 6, and 12 months postablation. The primary outcome was recurrence of any atrial arrhythmia after a 90-day blanking period. Safety outcomes included the composite of in-hospital major adverse events. ResultsA total of 533 patients with persistent AF underwent PVI using PFA (n = 214, 39%), CBA (n = 190, 36%), or RFA (n = 129, 24%). Procedures with PFA guided by fluoroscopy were shorter than those with CBA (median 60 minutes; interquartile range [IQR] 53–80 minutes vs 84 minutes; IQR 68–101 minutes; P ≤ .001), and procedures with PFA in combination with 3-dimensional electroanatomic mapping were shorter than those with RFA (median 101 minutes; IQR 85–126 minutes vs 171 minutes; IQR 141–204 minutes; P < .001). Acute safety events occurred in 2.3%, 2.6%, and 0.8% in the PFA, CBA, and RFA groups, respectively (P = .545). The 1-year confounder-adjusted estimate for freedom from atrial arrhythmias was 62.1% for CBA, 55.3% for PFA, and 48.3% for RFA (CBA vs PFA: P = .79; CBA vs RFA: P = .009; PFA vs RFA: P = .010). ConclusionIn patients with persistent AF undergoing first PVI, 1-year confounder-adjusted outcomes are better with PFA and CBA than with RFA.

Lower Recurrence Rates of Atrial Fibrillation and MACE Events After Early Compared to Late Ablation: A Danish Nationwide Register Study.

Guidelines recommend prioritizing treatment with antiarrhythmic drugs before referral of patients with atrial fibrillation to ablation, delaying a potential subsequent ablation. However, delaying ablation may affect ablation outcomes. We sought to investigate the impact of duration from diagnosis to ablation on the risk of atrial fibrillation recurrence and adverse events. Using Danish nationwide registries, all patients with first-time ablation for atrial fibrillation were identified and included from 2010 to 2018. Patients were divided into 4 groups by diagnosis-to-ablation time: <1.0 year (early ablation), 1.0 to 1.9 years, 2.0 to 2.9 years, and >2.9 years (late ablation). The primary end point was atrial fibrillation recurrence after the 90-day blanking period, defined by admission for atrial fibrillation, cardioversions, use of antiarrhythmic drugs, or repeat atrial fibrillation ablations. The secondary end point was a composite end point of heart failure, ischemic stroke, or death, and each event individually. The study cohort consisted of 7705 patients. The 5-year cumulative incidence of atrial fibrillation recurrence in the 4 groups was 42.9%, 54.8%, 55.9%, and 58.4%, respectively. Hazard ratios were 1.20 (95% CI, 1.07-1.35), 1.29 (95% CI, 1.13-1.47), and 1.40 (95% CI, 1.28-1.53), respectively, with the early ablation group as reference. The hazard ratio for the combined secondary end point was 1.22 (95% CI, 1.04-1.44) in the late ablation group compared with the early ablation group. In patients undergoing ablation for atrial fibrillation, early ablation was associated with a significantly lower risk of atrial fibrillation recurrence. Furthermore, the associated risk of heart failure, ischemic stroke, or death was significantly lower in early-compared with late-ablation patients.

Pulsed field ablation technology for pulmonary vein and left atrial posterior wall isolation in patients with persistent atrial fibrillation.

Limited data exist on pulsed-field ablation (PFA) in patients with persistent atrial fibrillation (PeAF) undergoing left atrial posterior wall isolation (LAPWI). The Advanced TecHnologies For SuccEssful AblatioN of AF in Clinical Practice (ATHENA) prospective registry included consecutive patients referred for PeAF catheter ablation at 9 Italian centers, treated with the FARAPULSETM-PFA system. The primary efficacy and safety study endpoints were the acute LAPWI rate, freedom from arrhythmic recurrences and the incidence of major periprocedural complications. Patients undergoing pulmonary vein isolation (PVI) alone, PWI + LAPWI and redo procedures were compared. Among 249 patients, 21.7% had long-standing PeAF, 79.5% were male; mean age was 63 ± 9 years. LAPWI was performed in 57.6% of cases, with 15.3% being redo procedures. Median skin-to-skin times (PVI-only 68 [60-90] vs. PVI + LAPWI 70 [59-88] mins) did not differ between groups. 45.8% LAPWI cases were approached with a 3D-mapping system, and 37.3% with intracardiac echocardiography. LAPWI was achieved in all patients by means of PFA alone, in 88.8% cases at first pass. LAPWI was validated either by an Ultrahigh-density mapping system or by recording electrical activity + pacing maneuvers. No major complications occurred, while 2.4% minor complications were detected. During a median follow-up of 273 [191-379] days, 41 patients (16.5%) experienced an arrhythmic recurrence after the 90-day blanking period, with a mean time to recurrence of 223 ± 100 days and no differences among ablation strategies. LAPWI with PFA demonstrates feasibility, rapidity, and safety in real-world practice, offering a viable alternative for PeAF patients. LAPWI is achievable even with a fluoroscopy-only method and does not significantly extend overall procedural times.

Rethinking appropriate blanking period after atrial fibrillation ablation.

Early recurrence (ER) within a 90-day blanking period (BP) in catheter ablation (CA) for atrial fibrillation (AF) is a risk factor for late recurrence (LR) after 90days postoperatively. However, few reports have examined them in the second CA and compared them to the first CA. Moreover, in recent years, there have been reports suggesting that BP should be reduced from 90 to 30days. Therefore, the association between ER and LR in the first and the second CA was examined, and the validity of a 30-day BP was evaluated. A total of 511 consecutive patients undergoing the first CA and 116 of these patients undergoing the second CA for AF at a single institution from November 2016 to December 2020 were analyzed retrospectively. When ER within a 90-day BP was divided into 0-30days and 31-90days according to the timing of the last ER episode, the hazard ratios on LR of them relative to no ER were 2.7 {95% confidence interval (CI) 1.7-4.2} and 9.7 (95% CI 6.6-14.3), respectively, for the first CA and 15.3 (95% CI 4.7-50.1) and 44.1 (95% CI 14.0-139.4), respectively, for the second CA. ER was strongly associated with LR, especially in patients with the last episode of ER more than 30days after CA. This was pronounced in cases after the second CA, when PVI appeared to be completed. With the current improvement in PVI durability, BP may be acceptable for 30days.

Pulmonary Vein Isolation in Elderly Patients ≥ 75 Years: A Propensity Score-Matched Analysis With Focus on Differences Among Atrial Fibrillation Types

BackgroundAge 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 uncertainties exist regarding efficacy and safety of ablation in elderly patients. MethodsThis was a prospective single-centre observational study with propensity score matching (PSM) to investigate the influence of age on efficacy and safety of cryoballoon ablation (CBA) stratified by age (< 75 years vs ≥ 75 years) and AF phenotype (paroxysmal vs persistent). Primary efficacy endpoint was recurrence of atrial arrhythmia after a 90-day blanking period. Safety endpoints were death, stroke, or procedure-associated complications. ResultsConsecutive patients (n = 953) underwent CBA for first-time AF ablation. Median follow-up was 18 months. By means of PSM, 268 matches were formed. At 1 year, primary efficacy endpoint occurred in 22.4% of young vs 33.2% of elderly patients, including both AF phenotypes (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.47-0.90; P = 0.01). AF relapse occurred in 19.7% of young vs 28.5% of elderly patients with paroxysmal (HR, 0.63; 95% CI, 0.40-0.99; P = 0.046) compared with 25.9% (30 of 116, young) vs 38.8% (45 of 116, elderly) patients with persistent AF (HR, 0.62; 95% CI, 0.39-0.97; P = 0.038). No difference was observed regarding the incidence of safety endpoints between young and elderly patients (P = 0.38). ConclusionsCBA is associated with higher recurrence rates in elderly (≥ 75 years) than in younger patients, with highest recurrence rates in elderly patients with persistent AF.

Contact-force local impedance algorithm to guide effective pulmonary vein isolation in AF patients: 1- year outcome from an international multicenter clinical setting

Abstract Background The combination of highly localized impedance (LI) and contact force (CF) may improve tissue characterization and lesion prediction during radiofrequency (RF) pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Objective We report the outcomes of our acute and long-term clinical evaluation of CF-LI guided PVI in consecutive AF ablation cases from an international multicenter clinical setting. Methods Consecutive patients (pts) from 16 European centers undergoing de novo AF RF catheter ablation with the Stablepoint catheter endowed of CF and LI measurement capabilities were enrolled in the CHARISMA registry. Ablation was guided by the magnitude and time-course of LI drop during RF delivery. The maximum distance between each ablation spot (center-to-center) was suggested to be ≤6 mm. Procedural endpoint was the achievement of the PVI as assessed by entrance and exit block. Post-ablation, all patients were monitored with ambulatory event monitoring. Additional ECG monitoring was performed as indicated by patient symptoms. Data are reported as mean±SD. Results From a total of 212 consecutive pts, 151 were followed-up for at least 12 months after the procedure and were included in this 1-year outcome analysis (61.6% paroxysmal AF, 38.4% persistent AF, 78.8% de novo procedures, 21.2% redo procedures). Baseline LI was 161.2±19 Ω with LI drop of 21.9±9 Ω (LI drop rate=3.1±2 Ω/s). The first pass isolation rate per vein was 93.3%. LI drop was predicted by baseline LI (r=0.56, 95%CI:0.55 to 0.57, p&amp;lt;0.0001). Effective ablation spots showed both higher baseline LI and LI drop compared with PV gap spots (161.4Ω vs 153.0Ω, p&amp;lt;0.0001 for baseline LI; 22.1Ω vs 14.4Ω, p&amp;lt;0.0001 for LI drop). No steam pops or complications, including atrio-esophageal fistula or tamponade were reported during or after the procedures. At the end of the procedures all PVs were successfully isolated in all study patients. During a median follow-up of 377 [365 – 402] days, 11 (7.3%) patients experienced an early recurrence of AF during the 90-day blanking period. Overall, 21 pts (13.9%) suffered an AF recurrence after the 90-days blanking period (10.8% with paroxysmal AF vs 19% with persistent AF, p=0.226; 10.9% for de novo procedures vs 25.0% for redo procedures, p=0.079). De novo paroxysmal AF pts showed the lowest rate of recurrence (5 out 69 pts, 7.2%). The time to recurrence was comparable among AF type (HR=1.73; 0.73 to 4.05; p=0.210 for persistent vs paroxysmal AF) whereas was shorter in repeated AF ablation procedures (HR=2.49; 1.04 to 5.98; p=0.042 for redo vs de novo procedure). Early recurrence was not associated with late recurrence (HR=2.29; 0.68 to 7.76; p=0.182). Conclusions In our experience, the magnitude of LI drop is predictive of PV segment isolation. An ablation strategy for PVI guided by CF-LI technology was safe and effective, and resulted in a low recurrence rate of AF at 1-year follow-up irrespective of underlying AF type.

Comparison of two commercially available cryoballoon ablation systems

Abstract Background Cryoballoon pulmonary vein isolation (PVI) is an established anatomical single-shot procedure for the treatment of atrial fibrillation (AF). Purpose We compared efficiency of two commercially available cryoballoon ablation systems (CBS) to treat AF. Methods We prospectively enrolled 121 consecutive AF patients and treated them with either a compliant or a non-compliant CBS. Results Evaluation of procedural characteristics revealed a significantly longer procedure duration (p=0.007) and fluoroscopy time (p=0.008) in the group of the compliant CBS. The nadir cryoballoon temperature was lower using the compliant system compared to the non-compliant CBS (p&amp;lt;0.0001), likewise the time to isolation was not different between both groups. The non-compliant CBS showed a better occlusion for the right superior pulmonary vein (RSPV, p=0.039) leading to a higher rate of isolation with first freeze (p=0.004) and lower number of ablations at the RSPV (p=0.015). A mean follow-up period of 310.8±189.7 days within a 90-day blanking period. 68% of patients treated with the non-compliant and 65% of patients treated with the compliant CBS showed freedom from atrial arrhythmia recurrence (p=0.724). Kaplan-Meier estimation showed no significant difference between both groups (LogRank p=0.768). Conclusion The novel compliant CBS showed a longer procedure duration and fluoroscopy time, as well as, a lower nadir cryoballoon temperature. The non-compliant CBS was more effective in isolation of the RSPV. Acute PVI success and long-term freedom from atrial arrhythmia recurrence after a mean follow-up of ten months did not differ between groups.

15-month follow-up of catheter ablation for atrial fibrillation in octogenarians

Abstract Background Catheter ablation for atrial fibrillation (AF) in octogenarians poses a challenge due to comorbidities, frailty, and suspected higher complication rates. Data regarding the outcome of catheter ablation in this population is scarce. Purpose Due to the projected increase of octogenarians presenting with AF in the future, we investigated the outcome of catheter ablation in this patient population. Methods We retrospectively analysed octogenarians with symptomatic AF undergoing catheter ablation in a single centre, including first and re-ablation procedures. Catheter ablation involved pulmonary vein isolation (PVI) using radiofrequency (RF), cryoballoon (CB) and pulsed field ablation (PFA) as energy sources and also atrial tachycardia (AT) ablation including linear lesions and/or ablation of complex fractionated atrial electrograms (CFAE). Follow-up (FU) was obtained to assess arrhythmia-free survival after a 90-day blanking period, recurrences after the blanking period, management of recurrences, rhythm at FU, use of antiarrhythmic drugs (AADs) and improvement in symptoms (EHRA symptom scale). Results A total of 126 patients (mean age 82.2 ± 1.9 years, paroxysmal AF n=48, persistent AF n=78, mean CHA2DS2-VASc-Score 4.2 ± 1.5) were included. 57.1% (n=72/126) underwent an index procedure {47.2% (n=34/72) RF PVI, 37.5% (n=27/72) CB PVI, 4.2% (n=3/72) PFA PVI and 11.1% (n=8/72) PVI + AT ablation}. 42.9% (n=54/126) received repeat procedures {20.4% (n=11/54) re-PVI, 42.6% (n=23/54) re-PVI + AT ablation, 37% (n=20/54) AT ablation}. FU of 108 patients after 15.4 ± 3.6 months revealed arrhythmia-free survival after the blanking period in 64.8% (n=70/108). Recurrence after the blanking period was seen in 35.2% (n=38/108). No significant difference in recurrences was shown between index and repeat procedures (32.3%, n=20/62 after index procedures and 36.7%, n=18/49 after repeat procedures, p =0.97). Management of recurrence involved repeat ablation (47%, n=18/38), AADs (16%, n=6/38), cardioversion (21%, n=8/38), pacemaker-implantation/AV-node ablation (5%, n=2/38) and pharmacological rate control (11%, n=4/38). At FU, 88.9% (n=96/108) of patients were in sinus rhythm with 21.3% (n=23/108) receiving AADs, 7.4% (n=8/108) were in AF, 0.9% (n=1/108) in AT and 2.8% (n=3/108) pacemaker-dependant. Symptoms were significantly improved at FU (mean EHRA score at FU= 1.2 ± 0.5, before ablation= 2.4 ± 0.5, p &amp;lt;0.0001). Conclusion Catheter ablation for AF in octogenarians is effective in maintaining sinus rhythm and controlling AF-related symptoms. Longer term success and impact on prognosis in this patient population is unknown and should be investigated further.

Abstract 14367: Multimodal Artificial Intelligence Algorithm to Distinguish Paroxysmal versus Persistent Atrial Fibrillation and Predict Outcomes After Ablation

Introduction: We aimed to develop effective multimodal machine learning (ML) techniques to predict: 1) duration of AF; 2) arrhythmia recurrence after ablation. Methods: Clinical data, intracardiac EGMs and metabolomic samples were obtained from patients undergoing AF ablation. Patients were prospectively followed to assess for recurrence after a 90-day blanking period with monitors every three months and if symptomatic. A prototype model was implemented via projection onto latent structures (PLS) logistic regression (LR), which accounts for collinearity in the predictors by estimating a small number of latent vectors that are aligned with the binomial response. PLS LR was used to estimate models for distinguishing paroxysmal from persistent AF and predicting recurrence. The latent structures identified by PLS LR combine strength from measurements of multiple correlated features. We generated a reference distribution to assess whether the model is better than chance by permuting the responses while keeping the inputs fixed. Models were compared based on the Akaike Information Criterion. Results: Three models were compared: EGM data (n=39), metabolomic data (n=29), multimodal approach on the combined two datasets (n=23). The multimodal model consistently produced a better fit despite smaller sample size. Only the model based on EGMs was significantly better than chance at distinguishing PAF from PeAF (p=0.03). The models based on EGMs and the combined data were significantly better than chance at predicting recurrence (p=0.02, p=0.04, respectively). Predictor EGM and metabolomics variables are shown in tables. Conclusion: Multimodal ML algorithm is promising to effectively combine multidimensional data for clinical use. The combined model consistently produced a better fit compared to the others, indicating that multimodal approaches are promising. According to AIC, the fit was better when the datasets were combined.

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

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

Early recurrences predict late therapy failure after pulsed field ablation of atrial fibrillation.

Pulsed field ablation (PFA) is a new ablation technology for atrial fibrillation (AF). Data regarding early recurrences of atrial tachyarrhythmia (ERAT) after PFA-pulmonary vein isolation (PVI) are sparse. Consecutive patients with symptomatic AF were enrolled to undergo PFA-PVI. A dedicated catheter delivering bipolar energy (1.9-2.0 kV) was used. Late recurrence (LR) was defined as documented AF/atrial tachycardia (AT) lasting more than 30 s after a 90-day blanking period. Two hundred and thirty-one patients (42% female, age 69 ± 12, 55% paroxysmal AF [PAF]) were included in this analysis. Median follow-up time was 367 days (interquartile range: 253-400). Forty-six patients (21%) experienced ERAT after a median of 23 days (46% in PAF and 54% in persistent AF [persAF]). Kaplan-Meier estimated freedom of AF/AT was 74.2% at 1 year, 81.8% for PAF, and 64.8% for persAF (p = .0079). Of patients experiencing ERAT, an LR was observed in 54%. There was no significant difference of LR between those who presented with very early ERAT (0-45 days) and those with ERAT (46-90 days) (p = .57). In multivariate analysis, ERAT (hazard ratio [HR]: 3.370; 95% confidence interval [95% CI]: 1.851-6.136; p < .001) and female sex (HR: 2.048; 95% CI: 1.114-3.768; p = .021) were the only independent predictors for LR. ERAT could be recorded in 21% of patients after PFA-PVI and was an independent predictor for LR. We found no difference in the rate of LRs among patients experiencing ERAT before or after 45 days.

Novel or established cryoballoon ablation system for pulmonary vein isolation: the prospective ICE-AGE-1 study.

Catheter ablation with a cryoballoon (CB) provides effective and durable pulmonary vein (PV) isolation (PVI) associated with encouraging clinical outcome data. The novel POLARx CB incorporates unique features, which may translate into improved safety, efficacy, and outcomes. The ICE-AGE-1 study aimed to assess the efficacy, safety, and 1-year clinical follow-up of the POLARx CB in comparison to the Arctic Front Advance Pro CB (AF-CB4). A total of 103 consecutive patients with paroxysmal or persistent atrial fibrillation (AF) who underwent POLARx-based PVI (POLARx group) were prospectively enrolled and were compared to 102 consecutive patients previously treated with the AF-CB4 (AF-CB4 group). The mean age was 68.7 ± 10.2 (POLARx) and 65.7 ± 12 (AF-CB4, P = 0.0551) years. A total of 412 (POLARx) and 404 (AF-CB4) PVs were identified. All PVs, except for one PV in the POLARx group, were successfully isolated. A significant difference regarding the mean minimal CB temperature reached using the POLARx CB (-56.1 ± 8.3°C) and AF-CB4 (-46.9 ± 10.1°C) was observed (P < 0.0001). Real-time PVI was visualized in 71% of PVs in the POLARx group and 46% of them in the AF-CB4 group (P < 0.001). The mean procedure time was comparable: 54.5 ± 17.1 min for POLARx and 59.4 ± 18.6 min for AF-CB4 (P = 0.0509). No differences were observed in terms of periprocedural complications. There were comparable rates in freedom of AF or atrial tachycardia recurrence after 12 months, beyond a 90-day long blanking period: 78.9% in the POLARx group vs. 77.2% in the AF-CB4 group (P = 0.804). The novel POLARx CB showed similar safety, efficacy, and 1-year recurrence-free survival rates compared to the AF-CB4. A higher rate of real-time electrical PV recordings and significantly lower balloon temperatures were observed using the POLARx as compared to AF-CB4.

Cryoballoon pulmonary vein isolation for atrial fibrillation in obese patients: A non-inferiority analysis

BackgroundPatients with obesity are at higher risk of developing atrial fibrillation (AF) and benefit from radiofrequency ablation. Potentially, cryoballoon ablation (CBA) may be equally effective and safe in such patients. MethodsWe conducted a prospective, single-center study to investigate whether CBA for pulmonary vein isolation is as effective and safe in obese patients as it is in non-obese controls. Primary efficacy endpoint was recurrence of AF, atrial flutter or atrial tachycardia after a 90-day blanking period. Safety endpoints were death, stroke or procedure-associated complications. Conduction of a subgroup analysis regarding the impact of additional diabetes was predefined in case the primary efficacy endpoint was met. The study was event driven and powered for noninferiority. ResultsA total of 949 patients underwent CBA (251 obese with mean body-mass-index 33.5 ± 3 kg/m2 and 698 non-obese with mean body-mass-index 25.3 ± 3 kg/m2) during a 5-year recruitment period. Median follow-up was 15 months. The primary efficacy endpoint occurred in 78/251 obese and 247/698 non-obese patients (12-months Kaplan-Meier event-rate estimates, hazard ratio 0.79; 95% confidence interval [CI], 0.58 to 1.07; log-rank P = 0.0002 for noninferiority). No differences were observed in safety end point occurrence (P = 0.78). The occurrence of primary efficacy end point was found to be unaffected by the presence of diabetes in the prespecified subgroup analysis (log-rank P = 0.57). ConclusionCBA is effective and safe in obese and DM patients. Weighing the high cardiovascular risk of obese patients against a reduction of cardiovascular events by early rhythm control, CBA should be offered to this patient population.

Efficacy and safety outcomes of early versus late cryoballoon ablation of atrial fibrillation - 24-months-results from the Cryo Global Registry

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Medtronic, Inc., Minneapolis, MN, USA Introduction Increasing evidence suggests early rhythm-control therapy in atrial fibrillation (AF) results in higher freedom from atrial arrhythmia (AA) recurrence and improved cardiovascular outcomes. However, the impact of specifically early cryoballoon ablation (CBA) is not well known. Purpose To assess the impact of early CBA of atrial fibrillation on efficacy and safety outcomes. Methods We evaluated AA recurrence (≥30 sec after a 90-day blanking period), repeat ablation, and serious procedure-related complications in patients with early vs. later CBA (≤12 vs. &amp;gt;12 months from diagnosis) in patients enrolled in the prospective, multicenter (121 centers in 37 countries). Subjects underwent CBA and were followed either 12 or 24 months per local standard of care. Results A total of 3447 subjects were followed through 12 months and a subset of 1220 through 24 months. In summary, 1573 patients (46%) had early CBA treatment at a median [IQR] of 0.3 [0.1 – 0.6] years from AF diagnosis (age 62±12 years, 35.8% female, 71.4% paroxysmal AF), and 1874 (54%) had later treatment at a median of 3.4 [1.9 – 6.7] years after diagnosis (age 61±11 years, 36.2% female, 75.0% paroxysmal AF). Early treatment patients were less hypertensive (53.5% vs 57.9%, p=0.01), had smaller left atrial diameters (41±7mm vs 42±7mm, p&amp;lt;0.01), lower BMI (27±5kg/m2 vs 28±5kg/m2, p&amp;lt;0.01), and less AF symptoms (1.5±1.1 vs 1.8±1.1, p&amp;lt;0.01). Early treatment was associated with higher acute procedural success (97.1% vs 95.2%, p&amp;lt;0.01). Freedom from AA recurrence in the early vs. later group was 86.0% (95% CI: 83.9-87.9%) vs. 81.0% (95% CI: 79.0-82.8%) at 12 months and 80.9% (95% CI: 77.9 – 83.5%) vs. 72.0% (95% CI: 69.0 – 74.7%) at 24 months (both P&amp;lt;0.01). Freedom from repeat ablation was high and not different between early and later treatment groups at 12 (93.6% vs 93.8%) and 24 months (90.2 vs. 89.2%), respectively (p=0.82). Serious procedure-related adverse events occurred in 2.4% and 3.5% of patients in the early and later treatment groups (p=0.045), respectively. Conclusions After AF diagnosis, early vs. later CBA results in higher freedom from AA recurrence and is associated with fewer safety events in a real-world evaluation. The difference in comorbidities at baseline between the two cohorts may contribute to the CBA being less effective in the later treatment cohort.

One-year follow-up after pulmonary vein isolation using pulsed field ablation for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). Only a few small clinical studies have been published on the mid- and long-term outcome. Here, we present the one-year clinical outcomes of PFA in PAF. Methods In PAF patients, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps using a pentaspline diagnostic cathter were performed. Procedural parameters, acute success, in-hospital safety and arrhythmia recurrence were assessed during one-year follow-up. Efficacy was evaluated by freedom from a ≥ 30-sec. recurrence of AF/atrial flutter (AFL)/atrial tachycardia (AT). Follow-up included 7-day Holter ECGs and/or telephonic interviews at days 90, 180 and 360 days after ablation. Results This study included a total of 108 patients (mean age 65±10 years; 44% female). Mean CHA2DS2-VASc-score was 2,3±1,7. Mean duration since first AF diagnosis was 45±63 months. Pre- and post-ablation high-density maps were performed in 36/108 (33%) of patients. Skin-to skin procedure time was 78±36 min. Fluoroscopy time and dose area product were 19±8 min and 5,56±4,64 Gy.cm2, respectively. Left atrial dwell time of the PFA catheter was 27±11 min. Acute PVI rate was 100% of PVs using PFA only. Primary adverse events occurred in 3,7% of patients (1 groin hematoma, 2 pericardial tamponades, 1 acute stroke with lethal outcome). No patients were lost during FU. During a mean FU of 346±64 days, 88 of 107 patients (82%) remained free of any symptomatic or documented AF/AFL/AT episode after a single procedure. After the 90-day blanking period, in 19 (18%) patients at least one episode of AF/AFL/AT was documented. In 14/107 (13%) patients, after 216±102 days a re-do procedure was performed. In 7/107 (7%) patients, PV reconduction was seen. In 5/107 (5%) patients, during re-do procedure clinical or induced typical or atypical flutter was treated in presence of durable PV isolation. In the remaining 2/107 (2%) patients, only clinical right atrial typical flutter was treated and no left atrial mapping was performed. Conclusions PVI using PFA in patients with a relatively long history of PAF results in a low one-year atrial arrhythmia recurrence rate. The success rate may be reduced due to the long duration since first AF diagnosis and the initial experience with PFA by the operators. PV reconduction rate during re-do procedure in a limited number of patients was 7%. There was a reasonable safety profile and it improved significantly over the course of time, indicating that the learning curve could have negatively influenced the incidence of complications. Figure: Kaplan-Meier analysis of freedom from atrial arrhythmias, including any AF/AFL/AT episode exceeding 30 sec. Not including the 3-month blanking period.

Hybrid ablation of atrial fibrillation: long-term outcomes from a single center prospective experience

Abstract Funding Acknowledgements Type of funding sources: None. Background/introduction Hybrid ablation of atrial fibrillation (AF) is emerging as a new technique for rhythm control with good clinical outcomes, especially in patients with non-paroxysmal AF. However, the role of hybrid AF in redo procedures is not clear. Moreover, long term clinical outcomes studies are lacking. Purpose The aim of this study is to define the long-term clinical outcomes of hybrid AF ablation in a large cohort from a single high-volume center. Furthermore, a correlation between the timing of hybrid AF and the outcomes is aimed. Methods All consecutive patients undergoing to hybrid AF ablation between 2014 and 2020 were enrolled in a prospective fashion. Hybrid ablation was performed in a one-step procedure consisting of: 1) Bilateral thoracoscopic epicardial ablation and 2) Percutaneous mapping and ablation. Pulmonary veins and posterior wall isolation was performed in all patients. Additional lesion set was performed based on physician judgement and clinical indication, including the following: superior vena cava isolation, bicaval line, anterior or posterior mitral line, cavotricuspid isthmus. Hybrid ablation time was analyzed as first hybrid procedure or redo hybrid after previous failed percutaneous procedure. The primary endpoint was defined as freedom from any atrial tachyarrhythmias (ATas) ≥ 30 seconds after a 90-day post-ablation blanking period. Results A total of 120 patients were included, 92 (76.7%) patients with persistent or long-term persistent AF and 28 patients (23.3%) with paroxysmal AF. Hybrid ablation was the first procedure in 85 (70.8%) patients and the second or third procedure (redo or re-redo) in 35 (29.2%) patients. Compared to patients with a second or third hybrid procedure, patients with a first hybrid procedure had more often persistent AF [81 patients (95.3%) vs 11 patients (31.4%), p&amp;lt;0.001]. At a mean follow-up of 52.1 months ± 29.0 there were 36 (30%) ATas recurrences, Figure 1. There was no significant difference in ATas free survival between patients with a first hybrid procedure and patients with a second or third hybrid procedure (69.4% vs 71.4%, Log-Rank p=0.81), Figure 2. Patients with a second hybrid procedure had higher ATas free survival compared to patients with a third hybrid procedure (86.4% vs 46.2%, Log-Rank p=0.01) Conclusion In a large cohort undergoing to hybrid AF ablation, the recurrence rate was 30% at a long-term follow-up of more than 4 years. Timing is of utmost clinical importance as delaying hybrid approach might be associated with worse clinical outcome.

PO-01-194 A COMPARISON OF CLINICAL OUTCOMES FOR THREE DIFFERENT MODALITIES USED FOR PULMONARY VEIN ISOLATION IN PATIENTS WITH ATRIAL FIBRILLATION

Pulmonary Vein Isolation (PVI) represents the cornerstone in atrial fibrillation ablation. The two most frequently used technologies for PVI are radiofrequency (RF) and cryoablation (CB). More recently, laser balloon (LB) has emerged as a promising therapy. Studies comparing all three modalities are lacking. We sought to compare clinical outcomes of RF, CB, and LB ablation in patients with atrial fibrillation from a prospective multi center registry. Between January 2018 and December 2021 912 patients from 3 U.S. centers underwent PVI catheter ablation with either RF, CB, or LB. Baseline clinical characteristic and procedural data were obtained (table). Patients were followed for 1 year. The primary outcome was time to atrial fibrillation. Secondary outcomes were time to any arrythmia and time to anti-arrhythmic drug therapy after the 90-day blanking period. A total of 912 patients were enrolled during the study. There were no significant differences at baseline between the groups with regards to sex, age, and prior cardiac history. 331 (36%) patients underwent PVI with CB, 227 (25%) underwent PVI with LB, and 354 (39%) underwent PVI with RF. There was no significant difference in time to recurrence of atrial fibrillation across treatment groups at 180 days (p=0.635) and at 360 days (p=0.425) (Figure). After 360 days there was a trend towards less recurrence of atrial arrythmias in the LB group vs the CB group (p=0.096). Time to use of AADs after the 90-day blanking period was significantly higher in the RF group after 360 days (p=0.009). In the cohort, atrial fibrillation was significantly associated with severe LA dilation [HR 1.841 (95%CI 1.044 to 3.247); p=0.035] and paroxysmal type of AF [HR 0.66 (95% CI 0.45 to 0.98); p=0.038]. The most common complication was groin hematoma. No atrioesophageal fistulae were observed. Death occurred in one patient unrelated to procedure. In this prospective cohort study, recurrence of atrial fibrillation was similar between all modalities at 1 year. There was a trend towards lower recurrence of atrial arrhythmia at 1 year in the LB group compared to the CB group. Patients who underwent RF PVI were more likely to be initiated on AAD therapy after the 90-day blanking period. Predictors of recurrence of AF included a severely enlarged LA and paroxysmal type of AF. Similar rates of procedural complications were seen across all treatment groups.Tabled 1Patient CharacteristicsCharacteristicOverallCryo, NLaser, NRF, Np-valueAge656566650.3Male Sex5572311861400.051Hypertension6812391652770.12Diabetes2006353840.3Coronary artery disease1926452760.6Stroke662511300.2Congestive heart failure168121128135<0.001AAD therapy4191391101700.6Procedure time (min)126121128135<0.001Vascular complications30030.12Post procedural stroke1003>0.9Phrenic nerve palsy72410.13Hematoma3085170.11Death10110.2 Open table in a new tab

PO-02-193 A COMPARISON OF THIRD GENERATION CRYOABLATION VERSUS X3 LASER BALLOON SYSTEMS FOR PULMONARY VEIN ISOLATION FOR TREATMENT OF ATRIAL FIBRILLATION

As the incidence of atrial fibrillation (AF) increases operators are looking to improve the efficiency of pulmonary vein isolation (PVI) with similar clinical outcomes. In a recent study the 2nd generation cryo-balloon (CB) and the 1st and 2nd generation laser balloon (LB) was compared with similar clinical efficacy but with shorter procedure time in the CB group. Improvements were made to both modalities in subsequent generation catheters. The 3rd generation CB (CB3) has a 40% shorter tip that allows for improved stability during cryo-applications. The X3 LB (LB3) introduced a “rapid” ablation mode which utilizes a motorized handle to allow for continuous 360-degree energy delivery to decrease ablation time and improve lesion effectiveness We sought to compare if these improvements impacted the overall efficacy, procedural and/or fluoroscopy time between the two modalities. To compare clinical outcomes of CB3 and X3 LB ablation in patients with AF in a multi-center prospective registry. Between November 2019 and November 2020, 69 patients with atrial fibrillation underwent ablation with either CB3 or LB3 at two large US medical centers. Patients were followed for at least 180 days after index procedures. The primary outcome was time to recurrence of AF. Secondary outcomes included time to anti-arrhythmic drug (AAD) therapy after the 90-day blanking period, and procedural characteristics. A total of 69 patients were enrolled in the study (baseline characteristics in Table 1). Forty patients (58%) underwent PVI ablation with CB3, and 29 patients (42%) underwent PVI ablation with LB3. There was no significant difference in the time to recurrent AF between treatment groups (p=0.865) (Figure 1). There was also no significant difference in the time to treatment with AAD therapy after the 90-day blanking period (p=0.125). Both procedural and fluoroscopy time were significantly shorter in the LB group (mean procedure time was 122 minutes in CB3 group versus 104 minutes in LB3 group and mean fluoroscopy time of 19.4 minutes in CB3 group versus 6.7 minutes in LB3 group) which was statistically significant for both parameters (p<0.001). There was no significant difference in adverse events between the two groups. LB and CB are safe and effective PVI modalities. Using the X3 LB system, procedure and fluoroscopy time were shorter than with the CB3 system with similar efficacy and safety. Larger prospective randomized studies are needed to confirm these results.

PO-01-097 HYPERLIPIDEMIA AS A PREDICTIVE RISK FACTOR OF ATRIAL ARRYTHMIA RECURRENCE FOLLOWING ABLATION: A DECAAF II SUBSTUDY

Multiple co-morbidities are known risk factors in atrial fibrillation (AF) recurrence following pulmonary vein isolation (PVI). Our aim was to assess the effect of hyperlipidemia (HLD) and statin therapy on atrial arrhythmia (AA) recurrence in persistent atrial fibrillation (PrAF) pts undergoing an initial PVI procedure. The DECAAF II trial was a prospective randomized controlled study evaluating the efficacy of MRI-guided fibrosis ablation compared to conventional ablation. Patient demographics, co-morbidities, medication regimens, baseline left atrial volume and atrial fibrosis were collected prior to ablation. After the procedure and 90-day blanking period, each participant submitted an ECG strip daily or when experiencing symptoms. A total of 826 pts were included, completed adequate follow up and had data regarding their HLD status. These pts were subsequently assessed for recurrent AA for 365 days post procedure. For this substudy, each patient was stratified into a HLD and non-HLD group irrespective of treatment modality. A covariate adjusted Cox regression model was used to assess determinants of AA recurrence. Lastly, a cox regression analysis was performed in patients taking HLD to assess for the effect of statins on AA recurrence. In the respective non-HLD and HLD groups, there was no statistical difference in mean left atrial volume (130±42 vs 135±38cc, p=0.08) and baseline fibrosis (19.0±7.4 vs 18.6±7.5%, p=0.43). However, there were statistically significant differences in age (61±9 vs 65±8 years, p=0.001), underlying hypertension (53.1 vs 69.1%, p=0.0001), diabetes (7.4 vs 14.5%, p=0.001), heart failure (16.8 vs 23.0%, p=.03) and obesity (52.4 vs 63.5%, p=0.002). When adjusted for these co-morbidities summarized in Table 1, analysis demonstrated HLD as a significant risk factor in procedural success and freedom from AA (Figure 1, p=0.02) with a hazard ratio of 1.30 (95% CI 1.05-1.61). Moreover, the use of statin therapy did not impact freedom from AA within the HLD group (Figure 1, p=0.51) with a hazard ratio of 0.83 (95% CI 0.58-1.12) HLD is an independent predictor of AA recurrence in PrAF pts undergoing PVI. However, statin therapy does not seem to improve AA recurrence after PVI in pts with PrAF and HLD.

PO-01-092 FIRST RESULTS FROM PVI WITH A NOVEL RADIOFREQUENCY BALLOON-CATHETER FOR THE TREATMENT OF PAROXYSMAL AND PERSISTENT ATRIAL FIBRILLATION

For patients with symptomatic atrial fibrillation (AF) pulmonary vein isolation (PVI) has evolved to the standard of care. For minimization of pulmonary vein reconnection, for reduction of complications and for improvement of PVI efficiency, also in a timely manner, many catheter technologies have been developed already. A new ablation modality in that regard is the radiofrequency balloon-catheter (RF-BC). However the evidence concerning this new technology is sparse. Evaluation of the procedural data, the safety profile and the clinical outcome using the new RF-BC in PVI. Since September 2021 patients with first-time PVI using the RF-BC (HELIOSTAR™, Biosense Webster) have been included in our ongoing monocentric register study. Esophageal temperature (ET) and phrenic nerve (PN) monitoring is performed during energy delivery. In case of ET exceedence above 42 degree Celsius an esophagogastroscopy (EGD) is conducted. Follow-up is scheduled for 3, 6, 12 and 24 months post ablation and in case of symptomatic recurrence. Until now 130 individuals (age [y]: 69 ± 9.8, female: 37.7%, paroxysmal AF 64.6%, CHA2DS2-VASc 4 ± 3, preserved ejection fraction 56.2%, left atrial diameter [mm] 45 ± 8.3) have been included in our study. Mean procedural duration (skin-to-skin) was 88 (± 35) minutes. Single-shot-isolation was possible in 80,2% of the 516 treated PVs. On average five energy deliveries per patient had been applied. Fortunately no pericardial tamponade, no stroke and no fatalities occurred. Nevertheless PN palsy was detected in one patient. Luckily it resolved completely within 48h. Due to ET exceedence in 6 of 20 patients esophageal lesions have been detected during EGD. All 6 lesions resolved spontaneously. Recurrence-free-survival after 6 months was 73.0% in the Kaplan-Meier analysis if no blanking period is applied, and 94.0% with a 90-day blanking period. Thanks to pulmonary vein isolation with only one energy-delivery in most cases, the RF-BC seems to be a very efficient ablation tool. But more importantly is seems to be also a safe one.