Acute Pulmonary Vein Isolation Research Articles

Multielectrode Radiofrequency Balloon Catheter for Paroxysmal Atrial Fibrillation: Results From the Global, Multicenter, STELLAR Study.

The safety and efficacy of paroxysmal atrial fibrillation (PAF) ablation with the HELIOSTAR multielectrode radiofrequency (RF) balloon catheter have been demonstrated in European studies; data from elsewhere are lacking. This prospective, multicenter study conducted in the United States, Italy, and China investigated the safety and efficacy of pulmonary vein isolation (PVI) using HELIOSTAR in drug-refractory symptomatic PAF. The primary effectiveness endpoint (PEE) was 12-month freedom from documented atrial fibrillation/atrial flutter/atrial tachycardia plus freedom from acute procedural failure, nonstudy catheter failure, repeat ablation failure, direct current cardioversion (DCCV), and Class I/III antiarrhythmic drug (AAD) failure. The primary safety endpoint was the occurrence of early-onset primary adverse events (PAEs). Cerebral magnetic resonance imaging (MRI) and cardiac computed tomography were performed in a patient subset to assess silent cerebral lesions (SCLs) and severe pulmonary vein (PV) stenosis, respectively. Across 36 centers, 257 eligible subjects in the main phase had the study catheter inserted. Acute PVI was achieved in all subjects, with the majority (94.1%) using the balloon catheter only. In 67.7% and 92.2% of subjects, respectively, PEE and freedom from repeat ablation were met; clinical success rate was 77.7%. The PAE rate was 5.1%. One of 15 (6.7%) subjects with MRI showed a new SCL at 1 month postablation, which resolved at 3 months. Clinically meaningful improvements in Atrial Fibrillation Effect on QualiTy-of-life scores were seen at 3 months and were sustained to 12 months postablation, and accompanied with reduction of Class I/III AAD use and DCCV. STELLAR confirmed the safety and efficacy of the HELIOSTAR catheter for PVI, with clinically meaningful improvements in quality of life in patients with drug-refractory symptomatic PAF. Most PVIs were achieved without focal touch-up, and > 90% of patients were free from repeat ablation at 12 months. ClinicalTrials.gov Identifier: NCT03683030.

Comparative Analysis of Real-World Clinical Outcomes of a Novel Pulsed Field Ablation System for Pulmonary Vein Isolation: The Prospective CIRCLE-PVI Study.

Background: Pulsed field ablation (PFA) represents a novel non-thermal approach for treating atrial fibrillation (AF) through pulmonary vein isolation (PVI). By utilizing irreversible electroporation, PFA creates lesions with minimal impact on adjacent tissues. This study investigates the procedural outcomes and safety of a novel circular PFA catheter in comparison to an established PFA system in a real-world clinical setting. Methods: This prospective, single-center study enrolled 125 consecutive patients with symptomatic paroxysmal or persistent AF undergoing first-time PVI with PFA at Ulm University Heart Center. Twenty-five patients underwent PFA PVI using a novel PFA system (PulseSelectTM, Medtronic, Dublin, Ireland) which incorporates a new circular catheter design and additional features such as ECG-triggered energy application and phrenic nerve capture testing. In comparison, 100 patients were treated using the established PFA system (FarapulseTM, Boston Scientific, Marlborough, MA, USA). Results: Acute PVI was achieved in 100% of the patients. Procedure duration, total left atrial (LA) time and fluoroscopy time remained comparable between both groups. The total number of energy deliveries was higher with the novel circular PFA catheter (34.0 vs. 32.0; p < 0.001). No procedure-related complications, including pericardial tamponade, phrenic nerve injury, atrial-esophageal fistula, vascular complications, embolisms, malignant cardiac arrhythmias, or coronary spasms were observed. Conclusions: The novel and the established PFA systems demonstrated comparable results in terms of procedure duration, fluoroscopy time, and LA time. In the hands of experienced operators, the novel circular PFA system enables an effective, consistent, and safe approach to successful PFA PVI.

Initial Real-World Experiences of Pulmonary Vein Isolation and Ablation of Non-Pulmonary Vein Sites Using a Novel Circular Array Pulsed Field Ablation Catheter.

Background and Aims: Various pulsed field ablation (PFA) systems are currently being developed. Recently, a novel CE-approved circular array PFA catheter (PulseSelect™ PFA System, Medtronic, Minneapolis, MN, USA) was introduced. Data on this commercially available system are sparse. The aim was to elucidate real-world data assessing the feasibility, safety, and acute efficacy of pulmonary vein isolation (PVI) and ablation beyond PVI with this novel ablation system. Methods: Consecutive patients with paroxysmal and persistent atrial fibrillation (AF) undergoing first-time ablation with the circular PFA catheter were enrolled in this study. In patients with persistent AF and left atrial (LA) enlargement (LA area > 20 cm2), additional left atrial roof ablation (LARA) was performed. Those with concomitant typical atrial flutter received adjunctive cavo-tricuspid isthmus (CTI) ablation. Results: A total of 100 AF patients were included (29% female, 50% persistent AF). Of these, 33 patients (33%) underwent adjunctive LARA, 1 patient (1%) received posterior wall isolation, and 6 patients (6%) required additional CTI ablation. The skin-to-skin procedural time averaged 66.3 ± 13.8 min, while the fluoroscopy time and dose area product were 13.7 ± 4.7 min and 6.8 ± 4.9 Gycm2, respectively. Acute PVI was achieved in 100% of pulmonary veins. A bidirectional conduction block of the LARA and CTI lines was confirmed in all patients, and no major adverse events were reported. Conclusions: These real-world data demonstrate the feasibility, safety, and acute efficacy of PVI and ablation beyond PVI using a novel circular array PFA catheter in patients with atrial fibrillation and flutter. The system can easily be integrated with standard PVI workflows. Further and larger studies are warranted to assess the clinical long-term effectiveness and safety of this PFA system.

Radiofrequency balloon ablation: 1-year outcomes of the AURORA study.

A novel irrigated radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) integrated into a 3D mapping platform was recently launched. Patients undergoing a first atrial fibrillation (AF) ablation at two German high-volume EP centers were included into the prospective AURORA registry. All patients underwent clinical follow-up (FU) at 90, 180, and 360days following ablation including 48-h Holter ECGs. A total of 99 patients were enrolled (43/99 (43.4%) women, median age 67years (interquartile range [IQR] 59-74), 43/99 (43.4%) persistent AF (Pers-AF), median left ventricular ejection fraction (LVEF) 60% (IQR 62-55)). Eighty-eight patients completed the follow-up. Acute PVI was achieved in 383/383 (100%) PV. Single-shot PVI was achieved in 211/383 (55.1%) PVs. Primary adverse events occurred in 3% of patients (1 postprocedural pharyngeal bleeding, 1 myocardial infarction, 1 non-cardiovascular death); no pericardial effusion, stroke, or phrenic nerve paralysis was observed. Median ablation and procedure times were 23 (IQR 18-32) and 67 (IQR 57-85) min, respectively. Median dose area product was 761 (IQR 509-1534) mGycm2. AF-free survival after a median FU of 361 (IQR 261-375) days was 78.4% for paroxysmal AF (PAF) and 75.4% for Pers-AF (p value = 0.828). Early recurrence of atrial tachyarrhythmia at the 90-day visit was the only independent predictor for AF recurrence at 1year upon multiple regression analysis (hazard ratio [HR] 3.198; 95% confidence interval [95% CI] 1.036-10.32, p value = 0.0433). RFB-based PVI is acutely successful, appears safe, and has comparable rhythm outcomes to other single-shot AF ablation tools. A recurrence of AF at 90days predicts later AF recurrence.

Role of 3D-electro-anatomical mapping on procedural characteristics and outcomes in pulsed-field ablation for atrial fibrillation

Abstract Introduction While the utilization of dedicated 3D-electro-anatomical mapping (EAM) systems for catheter ablation of atrial fibrillation (AF) is crucial using radiofrequency, its potential benefits in pulsed-field ablation (PFA) remain uncertain. This is of particular interest, since some PFA ablation systems will soon be available with integrated 3D-EAM capabilities. Objectives To compare the procedural characteristics and outcomes of patients undergoing PFA for pulmonary vein isolation (PVI) with mapping and with no mapping. Methods We prospectively enrolled patients undergoing their first PVI at a tertary referral center. In patients undergoing PVI with mapping, a multipolar mapping catheter was used to create voltage maps during sinus rhythm pre- and post-ablation. In the non-mapping group PVI was confirmed by assessing entrance block via the PFA catheter. The first 30 cases with mapping were excluded to account for a potential learning curve. Results A total of 197 consecutive patients were included (age 65 [interquartile range (IQR) 58 – 72] years; indexed left atrial volume 40 [IQR 35 – 44] mL/m2). Among these, 127 patients (64%) underwent PVI with mapping and 70 patients (36%) with no mapping. The median procedure duration, left atrial dwell time and the fluoroscopic time for the mapping vs the non-mapping group were 55 [IQR 45 – 67] min vs. 28 [IQR 23 – 35] min (p &amp;lt; 0.001), 38 [IQR 30 – 49] min vs. 15 [IQR 11 – 21] min (p &amp;lt; 0.001), 11 [IQR 9 – 14] min vs. 8 [IQR 7 – 11] min (p &amp;lt; 0.001), respectively. In the mapping group in 9% (11/127 patients) at least 1 PV was incompletely isolated and required additional applications. Acute PVI success was 100%. There were two complications in the mapping group (one stroke, one coronary artery air embolism) and none were observed in the non-mapping group. The recurrence rate of atrial arrythmias during a median follow-up of 267 [IQR 164 – 419] days was 14% in the mapping group and 17% in the non-mapping group, p = 0.728. Conclusion In conclusion, the use of PFA with no mapping was associated with a significant decrease in procedural characteristics, while AF-recurrence was not significantly different. The routine use of mapping for PFA-PVI may not be needed.Figure 1

Efficacy and safety of a novel hexaspline pulsed field ablation system in patients with paroxysmal atrial fibrillation: the PLEASE-AF study.

Pulsed field ablation (PFA) is an emerging non-thermal ablative modality demonstrating considerable promise for catheter ablation of atrial fibrillation (AF). However, these PFA trials have almost universally included only Caucasian populations, with little data on its effect on other races/ethnicities. The PLEASE-AF trial sought to study the 12-month efficacy and the safety of a multi-electrode hexaspline PFA catheter in treating a predominantly Asian/Chinese population of patients with drug-refractory paroxysmal AF. Patients underwent pulmonary vein (PV) isolation (PVI) by delivering different pulse intensities at the PV ostium (1800 V) and atrium (2000 V). Acute success was defined as no PV potentials and entrance/exit conduction block of all PVs after a 20-min waiting period. Follow-up at 3, 6, and 12 months included 12-lead electrocardiogram and 24-h Holter examinations. The primary efficacy endpoint was 12-month freedom from any atrial arrhythmias lasting at least 30 s. The cohort included 143 patients from 12 hospitals treated by 28 operators: age 60.2 ± 10.0 years, 65.7% male, Asian/Chinese 100%, and left atrial diameter 36.6 ± 4.9 mm. All PVs (565/565, 100%) were successfully isolated. The total procedure, catheter dwell, total PFA application, and total fluoroscopy times were 123.5 ± 38.8 min, 63.0 ± 30.7 min, 169.7 ± 34.6 s, and 27.3 ± 10.1 min, respectively. The primary endpoint was observed in 124 of 143 patients (86.7%). One patient (0.7%) developed a small pericardial effusion 1-month post-procedure, not requiring intervention. The novel hexaspline PFA catheter demonstrated universal acute PVI with an excellent safety profile and promising 12-month freedom from recurrent atrial arrhythmias in an Asian/Chinese population with paroxysmal AF. ClinicalTrials.gov Identifier: NCT05114954.

In vivo safety and pulmonary vein isolation performance of a new cryoballoon for the treatment of atrial fibrillation.

Cryoablation to achieve pulmonary vein (PV) isolation has become one of the standard approaches for atrial fibrillation (AF) ablation. The Arctic Front series cryoballoon and Achieve circular mapping catheter (Medtronic) inherently possess design defects that have been associated with unfavorite clinical outcomes. Lately, a new cryoablation system (Nordica Cryoablation System, Synaptic Medical) was developed with improved design of the cryoballoon and circular mapping catheter to address the inadequacies of current cryoablation technology. An animal study was conducted to test the efficacy and safety in performing PVI with the Nordica Cryoablation System. Pulmonary vein isolation with the Nordica Cryoablation System was performed on 12 PVs of six healthy canines. Acute PVI and peri-procedural complications were recorded. All animals underwent a repeat EP study at least 4 weeks after index procedures followed by pathological and histological assessments of the heart and collateral/downstream organs after planned euthanasia. Acute PV isolation was achieved in all targeted PVs with 50% of PVs being isolated with a single cryoablation application. There were no major peri-procedural complications or device malfunction events. All PVs remained isolated after 29-30 days follow-up. Histological examination showed transmural cryo-lesions at treated sites with minimal inflammation, neovascularization, and neointima formation but no significant injury to adjacent tissue or embolization in downstream organs. Acute and durable PVI can be achieved by using the novel Nordica Cryoablation System. Ablation with this new cryoablation system is associated with transmural lesions at targeted myocardium but creates no injury to the collateral tissues or downstream organs.

Pulmonary Vein Isolation with Pulsed Field Ablation and Size-Adjustable Cryo-Balloon: A Comparative Procedural Analysis of First-Time Use.

Background: Pulmonary vein isolation (PVI) is the standard of care for the treatment of symptomatic atrial fibrillation (AF). Novel techniques for PVI are the thermal size-adjustable cryo-balloon (CB) system and non-thermal pulsed field ablation (PFA) system. There are currently no data available for a direct comparison between these two systems. Furthermore, with new techniques, it is important to ensure a high level of efficiency and safety during treatment right from initial use. Therefore, the aim of this study was to directly compare the procedural data and safety of these two new PVI techniques in first-time users. Methods: We conducted a single-center prospective study involving 100 consecutive patients with symptomatic atrial fibrillation who underwent first-time PVI using either size-adjustable CB PVI or PFA PVI from July 2023 to March 2024. Results: Acute PVI was achieved in 100% of patients in both groups. First-pass isolation (FPI) was more frequently achieved in the PFA group compared to the size-adjustable CB group. The mean procedural duration and fluoroscopy dose were significantly shorter in the PFA cohort (p < 0.001). Furthermore, a significant reduction in fluoroscopy time was observed during the learning curve within the PFA group (p = 0.023). There were no major complications in both groups. Conclusions: Both systems demonstrate good effectiveness and safety during PVI performed by first-time users. However, the PFA group exhibited a significantly shorter procedural duration.

Assessing the impact of 3D imaging assistance on efficiency and safety in atrial fibrillation cryoablation

Abstract Introduction Pulmonary vein (PV) isolation is a cornerstone therapy for symptomatic atrial fibrillation (AF). Current 3D-navigation technologies used with radiofrequency (RF) ablation allow drastic reduction of X-ray exposure and better anatomical characterization improving acute and long-term procedural results. Cryoballoon ablation (CA) procedures typically rely on conventional fluoroscopy, resulting in significant X-ray exposure. Although contemporary fluoroscopy technologies allow for potential 3D imaging integration, their specific utility in improving procedural guidance during CA remains undefined. Method Using semi-automatic segmentation obtained from pre-procedural cardiac computed tomography, 3D segmentations of the left atrium, including PV, spine and primary bronchi walls were fused on the real-time fluoroscopy acquisitions in three standard positions (AP, LAO, RAO), acquired at the beginning of the procedure (Figure1). We compared procedural characteristics of CA performed with 3D-fusion imaging to conventional fluoroscopy-guided procedures. Results Thirty-six patients (aged 60±13 yo, 85% male) with paroxysmal AF treated with CA were included in the study: 18 in the control group (conventional fluoroscopy) and 18 in the 3D-assisted group. Acute PV isolation was achieved in all patients. The 3D-assisted CA was associated with significantly shorter procedure duration (mean 97.8±15.5 vs 82.1±16.1 min, p=0.0048); left-sided dwelling time (mean 77±15.2 vs 65.1±14.4 min, p=0.0351); and lower X-ray energy delivered to the patient (Dose Area product) with mean 661±373.1 vs 378.1±316.8 cGy*cm2 (p=0.013). Interestingly, we found that 72.2% of 3D guided procedures were done in less than 90min, while 77.8% of conventional cases required more than 90min to be completed (Figure 2D). Conclusion 3D-fusion imaging integration is feasible and allows for an exact PV anatomy depiction on fluoroscopy. Our data illustrates that it might significantly improve CA efficiency (shorter procedure duration) and safety (lower X-ray exposure and left-sided dwelling time). Our approach could also impact long-term results since it might reduce the likeability of missing intermediate PVs. Further research is needed to evaluate the incremental value of 3D imaging in long term efficacy.Figure 1Figure 2

Advanced pulsed field ablation: comprehensive analysis of safety and efficacy in a real-world cohort

Abstract Background Pulsed field ablation (PFA) represents a novel energy modality for catheter ablation of atrial fibrillation (AF). Initial preclinical and clinical studies indicate a higher safety profile with promising efficacy outcomes as well as shorter procedure times. Real world data are sparce and methods to improve clinical success rates are under development. Methods In this observational study 124 patients underwent pulmonary vein isolation with PFA (Farapulse, Boston) for paroxysmal and persistent AF. For anatomical visualization and optimal positioning of the PFA catheter a 3D mapping system was used (Ensite X, Abbott). Patients were followed over a 15-month period to evaluate both efficacy and safety of PFA in a real-world cohort using an advanced mapping technology. Results The patient cohort had a mean age of 67 ± 11 years, 38% females (n= 47), paroxysmal AF 53% (n = 66), persistent AF 47% (n = 58). Acute pulmonary vein isolation (PVI) rate was 100%. After a median FU of 6 months, 17 patients (14%) had a recurrence of AF. In our study population no esophageal complications, pulmonary vein stenosis, or persistent phrenic palsy occurred. Major complications were observed in 2.4% of the cases (3/124), involving two pericardial tamponades (1.6%) and one vascular complication with intervention (0.8%). There were no stroke events and no occurrences of death. Noteworthy was the absence of complications such as coronary arterial spasm or hemolysis-related acute renal failure. The average dose-area product and average procedure time were 9.54 ± 7.68 µGym² and 57.94 ± 18 minutes, respectively. Conclusion PVI with PFA in a real world cohort demonstrates a high safety profile. Furthermore, high clinical success rates can be achieved also in mixed paroxysmal/persistent AF populations. The use of 3D mapping systems might even improve clinical outcomes of PVI with PFA and will also help to guide more complex ablation strategies in the future. These findings pave the way for further exploration into the long-term benefits and broader applicability of PFA in AF ablation.

Acute clinical outcomes of patients with HFpEF undergoing atrial fibrillation ablation

Abstract Aim Robust data show that atrial fibrillation (AF) ablation can improve left ventricular function and prevent cardiovascular complications in patients with heart failure and reduced ejection fraction. The effectiveness and safety of AF ablation in patients with heart failure and preserved ejection fraction (HFpEF) is less well characterized. Methods We retrospectively analyzed 785 consecutive patients with normal left ventricular function undergoing AF ablation in a high-volume center including 251 with AF and HFpEF. We compared baseline parameters, procedural details and procedural complications by heart failure status. Results Patients with HFpEF (n=251/785) were older (median age 70 years vs. 64 years; p &amp;lt; 0.05) and more frequently female (48.2% vs. 32.2%; p &amp;lt; 0.05) compared to patients without HF. Symptom severity was comparable with a median European Heart Rhythm Association score of 2 in both groups (p &amp;gt; 0.05). Arterial (71.7% vs. 59.7%, p &amp;lt; 0.05), diabetes (16.7% vs. 9.4%, p &amp;lt; 0.05) and dyslipidemia (41.4% vs. 27.2%, p &amp;lt; 0.05) were more common in patients with AF and HFpEF. Acute pulmonary vein isolation (PVI) was achieved in all patients using cryoballoon or radiofrequency energy with similar frequency in both groups (cryoballoon ablation: 37.8% vs. 41.6%; p &amp;gt; 0.05). A subgroup of patients in both groups additionally underwent cavotricuspid isthmus ablation for coexistent atrial flutter (26% vs. 20.7%; p &amp;gt; 0.05). Procedure times (119.4 ± 47.7 min vs. 120.2 ± 48.3 min; p &amp;gt; 0.05) and fluoroscopy times (15.8 ± 10.4 min vs. 15.5 ± 7.1 min; p &amp;gt; 0.05) were comparable. Overall complication rates did not differ (12.7% vs. 10.3%; p &amp;gt; 0.05). While the incidence of pericardial tamponades was slightly higher (2% vs. 0%), other severe and minor complications showed no significant differences, including stroke/transient ischemic attack (TIA; 0.4% vs. 0.6%), major life-threatening bleeding (0% vs. 0.2%), vascular complications (1.6% vs. 2.1%), phrenic nerve palsy (0.8% vs. 1.5%), and pulmonary vein stenosis (0.4 vs. 0%). The mean in-hospital stay for the procedure was 2 days in both groups (p &amp;gt; 0.05). In-hospital recurrence rates were similar (12.4% vs. 17%; p &amp;gt; 0.05), as was the need for electrical cardioversion before discharge (5.6% vs. 6.6%; p &amp;gt; 0.05). Conclusion Patients with HFpEF undergoing AF ablation were older, more frequently female, and have more comorbidities than patients without heart failure. Acute procedural success and acute complication rates appear low. These data encourage randomized evaluations of the safety and efficacy of ablation-based rhythm control therapy in patients with AF and HFpEF.

Radiofrequency balloon ablation: 1-year outcomes of the AURORA registry

Abstract Background and Objectives A novel irrigated radiofrequency balloon (RFB) for pulmonary vein isolation (PVI) integrated into 3D mapping system was recently launched. Methods Patients ablated for paroxysmal atrial fibrillation (PAF) or persistent atrial fibrillation (persAF) at two German high-volume electrophysiology centers were included into the prospective AURORA registry. All patients underwent clinical follow-up (FU) at 90, 180 and 360 days following ablation including 24h Holter ECGs. Results A total of 101 patients were enrolled (50 from centre A, 51 from centre B) and 86 patients (48% male, 65 ± 11 years, 55% PAF, 59 ± 7% left ventricular ejection fraction (LVEF)) completed the follow-up. Mean ablation and procedure times were 26 ± 13 min and 71 ± 20 min, respectively. Dose area product was 1501 ± 1634 mGycm2. Acute PVI was achieved in 100%. Atrial fibrillation (AF) free survival after a mean FU of 361 (219-375) days was 78.4% for PAF and 75.4% for persAF. (p= 0.828). A multiple regression analysis did not reveal any clinical or procedural predictors of AF recurrence among sex, age, BMI, left atrial diameter, LVEF, ablation time, procedure time and single shot PVI. However, early recurrence of atrial tachyarrhythmia (ERAT) was an independent predictor for AF recurrence at 1-year (Hazard Ratio [HR]: 3.198; 95% confidence interval [95% CI]: 1.036 - 10.32, p value = 0.0433). Primary adverse events occurred in 3.5% of patients (1 postprocedural pharyngeal bleeding, 1 myocardial infarction, 1 non-cardiovascular death); no pericardial effusion, stroke or phrenic nerve paralysis were observed. Conclusions RFB-based PVI is clinically effective and safe. ERAT at the first follow-up visit is an independent predictor of late AF recurrence.

Durability of pulmonary vein isolation with pulsed field ablation compared to radiofrequency ablation in patients with persistent atrial fibrillation: results from a prospective remapping study

Abstract Background Pulsed field ablation (PFA) is a novel technology used for pulmonary vein isolation (PVI). Durability of PVI is critical to avoid atrial fibrillation (AF) recurrence. There is little data available on durability of PVI with PFA as compared to radiofrequency ablation (RFA), and on the mechanisms of arrhythmia recurrence in patients with persistent AF. Objective To invasively assess the durability of PVI with PFA compared to RFA using mandatory remapping studies after 6 months. Methods In a prospective study we included patients with symptomatic persistent AF to undergo a first PVI by either CLOSE protocol-guided RFA or PFA. Irrespective of AF recurrence, a remapping procedure was mandated 6-8 months following the index procedure to invasively evaluate PVI durability. The outcome of AF ablation was based on clinical recurrence and 7-day Holter-ECGs 3 and 6 months after the index procedure. Arrhythmia recurrence was defined as any atrial arrhythmia episode longer than 30 seconds beyond the 3-month blanking period. Results 60 patients (82% male; median age 68 years [60 – 74], median LAVI 47 ml/m2 [38 – 51]) undergoing PVI for persistent AF (median duration: 5 months [IQR: 3 – 9.5]) were included (30 in RFA group vs. 30 in PFA group). Procedure time was longer in the RFA group (169±39 min vs. 114±33 min, p&amp;lt;0.001), with longer fluoroscopy time in the PFA group (7.7±6.0 min vs. 19.7±7.5 min, p&amp;lt;0.001). Acute PVI was achieved in all 241 veins (100%) and no procedural complications were observed in either group. A median of 7.2 months after the index procedure 49 out of 60 patients underwent the remapping study (26 in RFA and 23 in PFA group; with some remapping procedures pending at the time of abstract submission). In the RFA group 78 out of 102 (76%) pulmonary veins (PVs) showed persistent isolation, compared to 74 out of 95 (78%) PVs in the PFA group (p=0.726). 15/26 (58%) RFA and 11/23 (48%) PFA group patients presented complete isolation of all PVs (p=0.594). Recurrence of arrhythmia was observed in 6/26 (23%) RFA and in 7/23 (30%) PFA group patients (p=0.542). Recurrence of persistent AF, paroxysmal AF, and atrial tachycardia was similar in both groups (RFA: 6 / 0 / 0; PFA: 5 / 1 / 1; p=0.612). In the pooled cohort, arrhythmias recurred irrespective of PV isolation status, in 7/26 (27%) patients with complete PVI vs. 6/23 (26%) patients with reconnected PVs (p=0.947). Similarly, the proportion of durably isolated PVs was not different in patients with (7/13; 54%) and without arrhythmia recurrence (19/36; 53%; p=0.947). Conclusions In patients with persistent AF undergoing mandated remapping procedure, we found comparable rates of durable PVI with RFA and PFA, both on a per-patient and a per-vein level. PVI with PFA was faster than RFA but required longer fluoroscopy time. Recurrence of AF was independent of durable PV isolation, underlining the need for additional ablation targets in a subset of patients with persistent AF.

Pulsed field ablation of atrial fibrillation using a large area focal catheter with a novel contact detection algorithm. A first-in-human experience using the QuickShot catheter

Abstract Background/Introduction Pulsed field ablation (PFA) is emerging as a safe and effective alternative energy modality for cardiac ablation. Data have shown that while tissue contact is critical for PFA, the amount of contact force is less important. Single-shot catheters have shown comparable results to current thermal methods for pulmonary vein isolation (PVI), however, are limited to anatomical-based ablation strategies and have limited ability to detect tissue contact. The investigational QuickShot™ large-area focal catheter (Galvanize Therapeutics, Redwood City, CA) combines high-density mapping with large-area focal ablation guided by contact detection. Purpose The QuickShot PEF-AF study was a prospective, single-arm, first-in-human study performed at a single European center to evaluate the safety and performance of the QuickShot catheter (see Figure 1, panel A) combined with the CE-marked CENTAURI™ System (Galvanize Therapeutics, Figure 1, panel B) for catheter ablation of atrial fibrillation (AF). Methods Subjects with paroxysmal or persistent AF underwent a PVI procedure under deep sedation (fentanyl, midazolam, propofol) guided by Rhythmia™ HDx (Boston Scientific, Marlborough, MA, Figure 1, panel D). Irrigation was set to a constant 6 mL/min during the procedure. Focal, monopolar, biphasic PFA lesions were delivered asynchronously at 33 Amps and a 10 mm inter-lesion spacing (center to center with 10 mm lesion tag size). Catheter-tissue contact was confirmed by ICE/fluoroscopy and a novel impedance-based contact detection system (Figure 1, panel C). The acute performance endpoint was PVI, assessed by entrance and exit block using high-density mapping. Procedural safety assessments included microbubble detection via ICE, induction of VT/VF, muscle stimulation, phrenic nerve function, and NIHSS post-procedure. Results Twenty (20) subjects (60% PAF, 60 ± 12 years, 75% male, 4.3 ± 0.52 cm LA AP diameter) were enrolled and treated. Acute PVI was achieved in 100% of patients and targeted PVs (82/82), with first-pass isolation in 88% of targeted PVs. The PVI time was 31 ± 10 min with 46.7 ± 11.4 PFA applications. There were no device- or procedure-related adverse events, and no documented incidence of microbubble formation, arrhythmia induction, muscle stimulation, phrenic nerve dysfunction, esophageal injury, or change in NIHSS post-procedure. Conclusion The QuickShot catheter enables safe and effective large-area focal PFA for subjects requiring PVI. The catheter design enables efficient and flexible focal lesion placement with the ability to ensure adequate apposition to targeted tissues using its novel contact detection algorithm. Future studies will investigate the use of this novel catheter for PFA strategies beyond PVI.

Procedural and outcome impact of body mass index on pulsed field ablation of atrial fibrillation: insights from the EU-PORIA Registry

Abstract Introduction Pulsed field ablation (PFA) is a "single-shot" non thermal ablation modality for atrial fibrillation (AF). In general, obesity is associated with increased risk of AF recurrence after catheter ablation with thermal energy sources. Purpose We aimed to assess the impact of body mass index (BMI) on procedural characteristics, safety, acute efficacy and long-term outcomes of PFA for symptomatic AF. Methods Of 1233 subjects enrolled in the EU-PORIA registry, in our subanalysis we included 1055 patients undergoing de novo pulmonary vein isolation (PVI)-only ablation procedure for symptomatic AF using the pentaspline PFA catheter from March 2021 until May 2022 at seven high-volume European centers. Patients were divided into two groups based on BMI: normal weight (nW, &amp;lt; 25 kg/m2) and overweight (oW, ≥ 25 kg/m2). Overweight patients were further categorized into three subgroups: pre-obesity (pOb, 25-29.9 kg/m2), obesity (Ob, 30-34.9 kg/m2) and severe obesity (sOb, ≥ 35 kg/m2). Clinical and procedural characteristics, complications and follow up data were collected. Results A total of 1055 patients (39% female, mean age 65,7±10,9 years, 65% paroxysmal AF) were enrolled. 32% of patients were normal weight (nW) and 68% overweight (oW). Among oW group, 438 subjects (41%) were assigned to pOb group, 204 (19%) to Ob, and 71 (7%) to sOb. Acute PVI was achieved in 100% of cases. The median skin-to-skin procedure and the median fluoroscopy time were similar between nW and oW and in all investigational subgroups, but radiation exposure increased in line with BMI (p&amp;lt;0.001). Periprocedural complications were 5% in nW, 1.6% in pOb, 3.9% in Ob, and 2.8% in sOb (p=0.06). The Kaplan-Meier estimate of arrhythmia-free survival was 80.2% in nW and 71.9% in oW (p=0.017). Each unit increment in BMI was associated with 4.2% increase in risk of AF/AT recurrence. Severe obese patients presented the highest 1-year AT/AF recurrence rate (37.2%). In the sOb group the rate of recurrence was not influenced by the type of AF (PAF 65.7% vs. pers AF 59.4%; p=0.484). Conclusion Overweight patients seem to experience more AF recurrences even after PFA PVI, mainly driven by a higher recurrence rate for BMI ≥ 35 kg/m2. Weight reduction programs remain crucial, nevertheless, reduced procedural times, good safety profile and acceptable 1-year observed AF/AT freedom make PFA a feasible strategy for AF rhythm control in patients with BMI ≥ 25 kg/m2.Freedom from AF/AT recurrence

Role of high-density voltage map guiding parosysmal atrial fibrillation ablation

Abstract Background High-density mapping of the pulmonary vein antra has been demonstrated to improve the detection of conduction gaps in wide antral catheter ablation (WACA) approach for the treatment of paroxysmal atrial fibrillation (AF). Purpose We aimed to compare the AF recurrencies in patients treated with WACA for pulmonary veins isolation (PVI) guided by high-density bipolar voltage map (BVM) vs WACA guided by a standard 20-pole circumferential mapping catheter (CMC-20). Methods This prospective study included patients scheduled for AF ablation in a single center. In group A (85 patients) PVI was achieved with a conventional approach using CMC-20; in group B (96 patients) high density BVM was acquired by sequential multielectrode mapping through Pentaray Catheter (Biosense Webster). More than 1000 voltage points per map were acquired. Acute PVI was defined as an entrance and exit block after ≥ 20 min waiting period. In both groups WACA was perfomed using a contact force sensing catheter targeting an interlesion distance ≤6 mm and ablation index ≥400 at posterior wall and ≥550 at anterior wall. The primary endpoint was the AF recurrencies in the two groups. Results A total of 181 patients were included (mean age 64.9±10.6 years, 33.1% female): in 85 patients AF ablation was guided by CMC-20, in 96 patients AF ablation was guided by BVM; WACA PVI was achieved in all patients. There were no significant differences in the clinical characteristics of the two groups (table 1). At 12-month follow-up, AF recurrencies were significantly lower in the BVM group compared with CMC-20 group [11/96 (11.4%) vs 19/85 (22.3%) respectively, p=0.01]. Conclusions High-density BVM might increase success rate of AF ablation compared with a conventional 20-pole circumferential mapping approach.

Implementation of nurse administered propofol sedation for same-day discharge pulsed field ablation of atrial fibrillation is safe and has excellent patient reviews

Abstract Background In June 2022, we introduced Pulsed Field Ablation (PFA) for de novo pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). Simultaneously, deep sedation with propofol undertaken by trained nurses from the cath lab was introduced. Purpose To evaluate feasibility, safety and patient reported experience for same-day discharge AF ablations performed with PFA on propofol sedation. Methods Patients with an ASA physical status classification of 1 or 2 referred for de novo AF ablation were planned for PFA in propofol sedation. Three nurses with previous experience from the intensive care unit planned and undertook the sedation. In addition, two nurses were trained locally. The initial 200 consecutive patients were included in the observational cohort study after signing consent to participate in follow-up after the procedure. Study data were collected and managed using REDCap electronic data capture tools. In addition to procedure related data, patient-reported quality measures were acquired 30 days after the procedure by an internet based questionnaire including scaling and open questions. Results 96% of the procedures were successfully completed using only propofol while 4% were scheduled for general anesthesia, mainly because of sleep apnea and high BMI. The average procedure time for the first 100 procedures was 57 min (95% CI, 54.1-62.9) and 45 min (95% CI, 42.6-47.4) for the following 100 procedures. Acute PVI was achieved during all procedures. No sedation related adverse effects were observed. One patient experienced pericardial tamponade requiring prolonged hospitalization. 87% were discharged on the same day as planned while 12% remained hospitalized one additional day for reassurance and social reasons. 93% (186/200) completed the questionnaire. 56% of patient only responded "very little" or "not at all" to all questions about adverse symptoms during and after the procedure. For each specific symptom, 80 to 95 % were only experienced "very little" or "not at all" (Fig 1). In general, patients felt safe about the preparation for and handling of the sedation (Fig 2). Conclusions Nurse administered deep sedation with propofol, provides excellent pain relief for PFA procedures, facilitates an efficient workflow and can safely be implemented and administered by nurses from the cath lab. Propofol sedation constitutes an important alternative to general anesthesia that is not widely available.Figure 1Figure 2

Adding 3D electroanatomical mapping to cryoballoon pulmonary vein isolation improves pulmonary vein isolation durability at repeat ablation procedure

Abstract Objectives The addition of pre- and post-ablation electroanatomical mapping with the Achieve catheter and EnSite mapping system has shown to improve acute pulmonary vein isolation (PVI) rate of cryoballoon ablation (CBA). Recently, our group also demonstrated an improvement in 1-year outcome. Current study aimed to investigate the impact on PVI durability as seen during repeat ablation procedure. Methods 400 patients were compared in a propensity-matched analysis between CT- and Achieve catheter guided CBA (Control group; N=200) and Achieve catheter guided CBA with additional EnSite voltage maps performed pre- and post-CBA (Mapping group; N=200). Matching parameters were age, AF type and CHADS-VASc score. In patients undergoing repeat procedure, PV status was evaluated using CARTO mapping system. Results Baseline characteristics did not differ between both groups (Persistent AF: 47,5% vs. 46,5%, P=0,841; diagnosis-to-ablation time: 28,1±15,1 vs. 33,2±41,7months, P=0,107). The mapping group had a shorter follow-up time (25,6±7,2 vs. 50,3±3,3months, P&amp;lt;0,001). Repeat ablation was performed in 20 patients in the mapping group and 70 patients in the control group. At repeat, the proportion of patients with persistent complete PVI was higher in the mapping group (14/20(70.0%) vs 23/70(32,9%), P=0,030). Interestingly, less reconnections of the right inferior PV were seen in the mapping group (10,0% vs. 34,3%, P=0,035). There was no difference in reconnection rate of other PVs. Conclusions The addition of electro-anatomical EnSite mapping to the Achieve catheter improves PVI durability as seen during repeat ablation, mainly at the level of the right inferior PV. This finding might explain the improvement in 1-year outcome of this approach.

Local impedance drop as a predictor of sucessful pulmonary vein isolation

Abstract 1. Introduction Pulmonary vein isolation (PVI) is the cornerstone of AF treatment. An accurate estimation of the lesion size and a optimal evaluation of the catheter-myocardium coupling is crucial for achieving an effective and safe radiofrequency (RF) ablation. A few studies have suggested that local impedance (LI) drop is a better predictor than general impedance drop in terms of lesion size, electrical coupling and therefore acute PVI success. An open-irrigated ablation catheter designed to measure contact force (CF) and LI drop while applying RF has been recently developed. 2. Purpose The aim of this study is to evaluate if conduction GAPS are located in certain areas and if LI drop can predict the presence of conduction gaps in each of these segments. 3. Methods Observational prospective study including 55 consecutive patients who underwent PVI. The RF lesions were delivered with 30 W (posterior wall) or 35 W (anterior wall) for a maximum of 30 seg with a CF &amp;gt; 5 g. The applications were stopped if a LI of 35 Ohm was reached on the posterior wall or 40 Ohm on the anterior wall. PVs were divided into seven segments and ablation tags were assigned to a segment according to their anatomical position (figure 1) We categorized the tags included in each segment as successful or not according to the presence of conduction gaps detected with an Ultrahigh density mapping catheter once the WACA was completed. At the same time lesion by lesion were studied regardless of the segment where it was located. 4. Results We analyzed 4002 lesion tags of 55 patients who underwent PVI. 53 Gaps were found in 19/55 (34.5%) left WACA and 16/54 (29,6%) right WACA and were localized predominantly in three PVI segments (L1, L6 and R3) 34(54.85%) vs 19 (35,8%) (L2-L5, L7, R1-R2, R4-R7) (p&amp;lt;0.001) (figure 1). They were mainly circumscribed to anterior segments in left PVs and posterior-superior segment in right PVs (figure1). When examining lesions independently of their location we found a significant difference in LI drop among successful and unsuccessful lesions (24.22±8.31 vs 15.67±7.85) Ohm, p&amp;lt;0.001). In the same line when studying lesions in those segments with &amp;gt; 10% of GAPS (L1, L6 R1 and R3) LI drop was greater in successful lesion tags: L1 25.2 ± 5.35 vs 16.8 ± 5.17 (p&amp;lt;0.001), L6 25.2±5.7 vs 16±5.48 (p&amp;lt;0.001), R1 27.9±4.78 vs 17.1±5.73 (p=0.03) and R3 18.5±5.4 vs 10.7±2.49 (p&amp;lt;0.001). 5. Conclusions Gaps were located predominantly in anterior segments in left PVs and posterior-superior segment in right PVs. A low LI drop was an excellent predictor of conduction gaps, and it performs well regardless of the segment where it was analyzedFig. 1

AF ablation using a novel “single-shot” map-and-ablate spherical array pulsed field ablation catheter: 1-Year outcomes of the first-in-human PULSE-EU trial

BackgroundDuring pulsed field ablation (PFA), electrode-tissue proximity optimizes lesion quality. A novel “single-shot” map-and-ablate spherical multielectrode PFA array catheter that is able to verify electrode-tissue contact was recently studied in a first-in-human trial of atrial fibrillation (AF). ObjectiveThe aim of this study was to report lesion durability data, safety, and 12-month effectiveness outcomes. MethodsThe spherical PFA catheter, an all-in-one mapping and ablation system, was used to render anatomy and to deliver biphasic pulses (ungated 1.7 kV pulses; ∼40 seconds/application). Ablation sites included pulmonary veins (PVs) and, in selected patients, posterior wall and mitral isthmus. Follow-up was invasive remapping at ∼3 months, electrocardiograms, Holter monitoring at 6 and 12 months, and symptomatic and scheduled transtelephonic monitoring. The primary and secondary efficacy end points were acute PV isolation (PVI), PVI durability, and atrial arrhythmia recurrence. ResultsIn the 48-patient AF cohort (paroxysmal, 48%; persistent, 52%), lesion sets included PVI (n = 48; 1.2 applications/PV), posterior wall (n = 20; 3.6 applications/posterior wall), and mitral isthmus (n = 11; 2.9 applications/mitral isthmus). Lesions were acutely successful for all 187 of 187 PVs (100%), 20 of 20 posterior walls (100%), and 10 of 11 mitral isthmuses (91%). Pulse delivery time, left atrial catheter dwell time, and procedure time were 61.5 ± 32.8 seconds, 53.9 ± 26.5 minutes, and 87.8 ± 29.8 minutes, respectively. Remapping (43/48 patients [89.5%]) revealed that 158 of 169 PVs (93.5%) were durably isolated. The only complication was a drug-responsive pericarditis. The 1-year Kaplan-Meier estimates of freedom from atrial arrhythmia were 84.2% (paroxysmal AF) and 80.0% (persistent AF). ConclusionThe single-shot spherical array PFA catheter can safely achieve durable lesions, translating into good clinical efficacy.