Rate Of Pulmonary Vein Isolation Research Articles

The contribution of pulmonary veins to the mechanism of persistent AF is dependent on their extent of electrical connection

Abstract Introduction Success rate of pulmonary vein isolation (PVI) is lower in patients with persistent AF (peAF) compared to paroxysmal AF. The indiscriminate use of adjunctive catheter ablation (CA) strategies beyond PVI involve potential risks and new areas of iatrogenic arrhythmogenesis. Thus, distinguishing patients with peAF who may be cured with PVI-only from those who need CA beyond PVI would allow a more efficient patient-tailored CA strategy. Purpose We aimed to evaluate whether the circumferential extent of PV electrical connection assessed during pre-ablation mapping predicts the success rate of a PVI-only CA strategy. Methods Consecutive patients with peAF undergoing first CA consisting of a PVI-only CA were included. The extent of PV electrical connection was assessed using a circular mapping catheter placed within the PVs prior to ablation. Based on their follow-up (FU), patients were considered: a) PVI-responders, in the absence of AF or atrial flutter recurrence ≥ 12 months off-anti-arrhythmic drugs, b) PVI-non responders, in case of AF recurrence despite absence of any PV reconnection at reintervention, or despite one reintervention consisting of stand-alone residual PV connection ablation, c) PVI response was considered as indeterminate for all other instances (eg. Sinus rhythm maintenance on-AAD, shorter FU, etc). Results 148 patients were included (mean age 64 ± 9.7 years, mean peAF duration 7.3 ± 7 months). After a mean FU of 18 months after last PVI, we identified 60 PVI-responders and 25 PVI- non responders. In the remaining 63 patients, PVI response was indeterminate. In PVI-responders, the median percentage of the PV circumference displaying PVs potentials was significantly higher compared to PVI-non responders (68% vs. 60%, respectively; p=0.035). Conclusions The circumferential extent of PVs connection is correlated to the success rate of a stand-alone PVI CA strategy in patients with peAF. It may be a marker of the contribution of PVs to AF. Patients with poorly connected PVs during index CA ablation may warrant additional ablation strategies beyond PVI.

Optimization of high-power short-duration pulmonary vein isolation using QDOT catheter - the A-Q-RATE POWER trial

Abstract Background/Introduction The safety and efficacy of novel ablation catheter QDOT Micro, capable of delivering high-power short-duration (HPSD) radio-frequency (RF) applications, has already been demonstrated in clinical trials. It has been shown that lesions performed with 90 Watts/4 sec (vHPSD) are shallower but wider compared to HPSD (50 Watts/4 sec) or conventional ablation settings. Thus, it may be speculated that vHPSD applications may not achieve transmurality at thick (up to 4 mm) parts of anterior aspects of pulmonary vein (PV) - left atrial (LA) wall junction. Purpose To compare acute completeness of PV isolation (PVI) focused on anterior wall achieved using vHSPD versus HPSD in patients undergoing ablation for atrial fibrillation (AF). Methods Prospective, dual-center, randomized study was conducted over a 8-month period. Patients were randomized 1:1 to vHPSD versus HPSD delivered at anterior aspects of PV. Posterior parts of PV were ablated with vHPSD in both arms. The carina region between ipsilateral PVs was ablated using 35 W and ablation index of 380. Need for additional RF applications to achieve complete PVI was the primary outcome. Results 70 patients (mean age 63.5±11.2; 57.1% male) with paroxysmal (61.4%) or persistent AF (38.6%) were randomized to vHPSD (n=35) or HPSD (n=35). Additional RF touch-up applications at the anterior aspects of PV were significantly more frequently needed in the vHPSD group compared with the HPSD group (46% vs 19%, p<0.001) and in the right PVs (57% vs 20%, p=0.001) versus left PVs (34% vs 17%, p=0.1). Median procedure duration, LA dwell time and fluoroscopy time were similar in both groups [112 (IQR 90, 130) min vs 107 (IQR 90,125) min, p= 0.58; 95 (IQR 70,106) min vs 90 (IQR 71,100) min, p=0.55; and 28 (IQR 14,69) sec vs 46 (IQR 0,89) sec, p=0.97, respectively). In one patient in vHPSD we were not able to isolate right superior pulmonary vein (RSPV) despite additional RF touch-up applications. Conclusions vHPSD RF applications using the QDOT Micro catheter may not achieve transmurality in a significant proportion of anterior parts of PV. The proposed hybrid strategy consisting of HPSD delivery at anterior aspects of PV with vHPSD delivered at other parts of PV ostia is associated with significantly higher rate of first-pass PVI without extending procedural and fluoroscopy duration.

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<0.001), with longer fluoroscopy time in the PFA group (7.7±6.0 min vs. 19.7±7.5 min, p<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.

Intra-procedural three-dimensional rotational angiography in cryoballoon ablation of atrial fibrillation - results from a randomised clinical trial

Abstract Introduction There are a variety of approaches for pre-procedural imaging to facilitate atrial fibrillation (AF) ablation. Intra-procedural three-dimensional rotational angiography (3DRA) is the least employed method and it can be advantageous regarding efficiency and procedural logistics (1). There is an open question whether LA imaging could improve safety and outcomes of cryoballoon (CB) ablation. Purpose The aim of this study is to evaluate possible benefits of 3DRA for procedural success, safety and long-term outcomes of CB ablation. Methods We designed a single-centre unblinded randomised clinical trial and recruited 134 patients (64.2% male, 59.0±11.6 years) with paroxysmal (93.3%) and early-persistent AF. Patients were randomised to no imaging or 3DRA which was performed intra-procedurally after trans-septal puncture. Angiographic images were segmented and overlaid to the fluoroscopy screen to guide the ablation procedure. Patients were scheduled for follow-up visits and twenty-four hour ECG recordings at 3, 6 and 12 months, and every 6 months thereafter. Results Of all the patients recruited, 66 (49.3%) were randomised to 3DRA and angiography was successfully performed in all but one patient (1.5%). Procedure time was significantly longer when 3DRA was performed (86.7±27.8 min compared to 67.2±22.1 in non-3DRA group, p<0.001). Total radiation dose (447.4±485.0 vs. 133.9±166.2 mGy, p<0.001) and contrast administration (131.8±28.3 vs. 40.8±26.5 ml, p<0.001) were significantly higher in the 3DRA group (Table 1). In patients who received no imaging one pulmonary vein (PV) couldn’t be isolated in 2 patients while this occurred in 3 patients in the 3DRA group (OR 1.57, 95% CI 0.25-9.72). Only minor complications were reported in both groups. Five patients developed large haematoma (4 in the 3DRA group vs. 1 in the control group). In each group there were 3 incidents of impending or transient phrenic nerve palsy. During 12 months of follow-up, 88.2% of patients in the control group and 81.8% in the 3DRA group were free of atrial fibrillation (OR 1.67, 95% CI 0.63-4.38). Two patients from the control group developed atrial flutter and were treated by ablation. In total, 10 patients underwent redo procedures (7 in the control and 3 in the 3DRA group respectively) and PV reconnections were detected in 9 cases. Conclusion 3DRA is a safe and efficient intra-procedural imaging method to guide CB ablation of AF. However, it significantly increases procedure duration, total radiation dose and contrast expenditure. In our trial it did not have any impact on the acute success rate of PV isolation or freedom from atrial fibrillation during 12-month follow-up.

Superior vena cava isolation in paroxysmal atrial fibrillation - mind the phrenic

Abstract Background Pulmonary vein isolation (PVI) is the standard of care for patients with atrial fibrillation (AF), but medium-term success rates are far from ideal. Therefore, new methods are being developed, with emphasis on ectopic foci outside the pulmonary veins. Superior vena cava (SVC) is one of the most important non-pulmonary origins of AF and some studies suggested that empiric SVC isolation could improve outcomes in ablation of paroxysmal atrial fibrillation (PAF). Although complications have been reported in SVC ablation, most studies found complication rates of SVC ablation similar to conventional cryoballoon PVI. Aim This prospective, single-center study aimed to assess the complication rate and success rate of PVI followed by SVC isolation by cryoballoon application in comparison with conventional cryoballoon PVI. Methods We designed an unblinded, randomized clinical trial and recruited consecutive patients with PAF who were randomized to a conventional cryoballoon PVI or PVI and additional SVC cryoballoon isolation using single 180 s freeze. Results A total of 140 patients (61.4% male, mean age 62.1 years) with PAF were included and 67 (47.9%) were randomized to SVC isolation in addition to conventional ablation. Planned 180-s freeze in the SVC could be completed in 15 (22.4%) patients, while 27 (40.3%) patients received at least 120-s freeze. The mean time to SVC isolation was 40.2 ± 37.9 s. Real-time recording of SVC isolation was observed in 39 (58.2%) patients. Right phrenic nerve palsy (PNP), impending or transient, occurred in 6 (8.2%) patients in the PVI-only group and in 25 (37.3%) patients in the SVC-group (Chi-square test p < 0.001). There were no persistent PNP cases. Bradycardia or junctional rhythm was observed during a procedure in 15 (22.4%) patients who received SVC isolation. One patient eventually received a permanent AAI pacemaker due to a sinus node injury. Conclusion Our data suggest that SVC isolation can be successfully achieved in the majority of PAF patients using conventional cryoballoon. However, this significantly increases the rate of transient or impending PNP and sinus node injury in comparison to conventional cryoballoon PVI. Therefore, careful phrenic nerve function monitoring and attention to sinus bradycardia or junctional rhythm are important to mitigate this risk. Follow-up data are being collected to determine whether this risk could be outweighed by a lower rate of PAF recurrence.

Association between left atrial wall thickness and residual potential after first-pass pulmonary vein isolation using very high-power short-duration ablation in patients with atrial fibrillation

Abstract Background In this study, we evaluated efficacy, efficiency, and safety of pulmonary vein isolation (PVI) applying vHPSD ablation strategy in patients with atrial fibrillation (AF) and explored the association between left atrial wall thickness (LAWT) and the residual potential after first-pass PVI. Methods Between April 2, 2023 and October 6, 2023, drug refractory symptomatic AF patients who underwent AF ablation using vHPSD ablation strategy with QDOT MICRO catheter were prospectively enrolled. All patients took cardiac computed tomography (CT) a day before procedure. Using CT image, LAWT map was created. PV segments were categorized into prespecified 14 segments, and LAWT of each segment, segments with residual potential (RP) after first-pass PVI and early reconnection after 20-minute waiting after PVI were evaluated. Total procedure time, ablation time for PVI, and occurrence of procedure-related complication were collected. Results A total of 40 patients were included (mean age 64 years, 45% of persistent AF). Additional ablation other than PV was performed in 48% of patients, total procedure time was 77 minutes, and total PVI time was 9.9 minutes. With vHPSD PVI, all PVs first pass isolation rate was 60%; in terms of per PV, RSPV first-pass isolation was 88%, followed by LSPV and LIPV 85%, RIPV showed lowest first-pass isolation rate, 75% (Figure A). Most common RP sites was right carina, followed by left carina (Figure A). Compared to historical comparator, vHPSD PVI showed shorter procedure time, shorter ablation time for PVI, with numerically lower but statistically comparable first-pass PVI rate (Figure B). In total 560 PV segments in 40 patients, RSPV anterior, left carina, and right carina showed higher prevalence to be thick PV segments (over 60% of patients), followed by RPSV posterior, LSPV posterior, and RIPV anterior (over 40% of patients). Looking into ablation parameter detail, mean contact force was 10g, mean temperature was 47°C, and mean impedance drop was 8.4Ω. Compared to segments without RP, segments with RP showed thicker mean left atrial wall thickness grades, lower minimum contact force, higher maximum temperature, and lower minimum impedance drop. According to the left atrial wall thickness, thick PV segments showed higher prevalence of RP after first-pass PVI with vHPSD ablation. In segments with LAWT grade 3 or more, the RP rate was 9.1%. This thickness means thicker than 1.5 to 2.0 mm of thickness (Figure C). In 10% of patients (n=4) had audible or tactile steam-pops, visible char was confirmed in 5% of patients (n=2). There were no clinical complications. Conclusion PVI using vHPSD achieved shorter procedure time, shorter ablation time for PVI, and comparable first-pass PVI rate compared to historical comparator using ablation-index guided conventional power ablation. Thick segments had higher chance to have residual potential after first-pass PVI with vHPSD.

Long‐term outcome of high‐power ablation guided by ablation index in the treatment of atrial fibrillation

AbstractObjectiveHigh‐power ablation has been widely used in atrial fibrillation (AF). However, there were many studies observed the outcomes of the short‐term follow‐up. This study aims to the long‐term results of high‐power ablation guided by ablation index (AI) in patients with AF.MethodsAnalysis of patients with AF, who first received high‐power (40–50 W) ablation, to pulmonary vein isolation (PVI) in the Second Hospital of Shanxi Medical University from May 2020 to March 2022. All patients were managed perioperatively according to the routine treatment procedures. High‐power ablation was conducted under the guidance of our conventional power AI and baseline data, first‐pass PVI rate, ablation time, operative time, and long‐term surgical success rate were analyzed.ResultsA total of 83 patients with atrial fibrillation were enrolled in the study, with an average age of 61.62 ± 9.04 years, 47 male patients, and 49 paroxysmal atrial fibrillation. All patients achieved PVI, and the rate of first pass was 82%. The ablation time of the left atrial was 28.54 ± 9.11 min. There were no serious complications related to ablation, and only a small amount of pericardial effusion was found in 4 patients. During the follow‐up period of 26.36 ± 6.11 months, 8 patients were lost to follow‐up and the overall success rate was 84%, including 91% for paroxysmal AF and 71% for persistent AF.ConclusionHigh‐power ablation long‐term results appear a high freedom atrial arrhythmia, but further expanded samples are needed for controlled studies.

Durability of CLOSE-Guided PulmonaryVein Isolation in Persistent Atrial Fibrillation: A Prospective Remapping Study.

Recurrence 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. To evaluate the lesion durability by means of an a priori planned remapping procedure in patients with persistent AF undergoing CLOSE-guided PVI. In a prospective study, we included patients with symptomatic, persistent AF undergoing CLOSE-guided radiofrequency ablation. Irrespective of AF recurrence, a redo procedure was mandated 6months 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 6months after the index procedure and 3, 6, and 12months after the redo procedure. Of 30 patients included, 26 (81% men; median age 68 years) underwent the planned remapping study a median of 6months 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 12months. In 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.

Population rates and contemporary outcomes of atrial fibrillation ablation among older adults: a nationwide cohort study

Abstract Background Atrial fibrillation (AF) is the most common sustained arrhythmia, with pulmonary vein isolation (PVI) increasingly recommended as first-line therapy. Limited data suggest increasing use of PVI as well as increasing rates of post-PVI complications, but contemporary real-world outcomes among older adults remain unclear. Purpose To evaluate patient characteristics, population rates and 30-day clinical outcomes for PVI in a nationwide sample of adults aged >65 in the United States. Methods First-time PVIs were identified among US Medicare fee-for-service beneficiaries using CPT procedural codes, and comorbidities were ascertained using ICD-10 diagnosis codes associated with each procedural claim. Study outcomes included rates of PVI use, procedural complications, all-cause re-hospitalizations, and all-cause mortality at 30 days. Results From January 2017 through December 2020, 156,601 patients underwent first-time PVI performed by 2,791 unique operators. The mean patient age was 72.5 ± 5.2 years, 42.6% were female and the majority (92.7%) Caucasian. The rate of PVI increased from 2.48 per 100,000 beneficiaries in the first quarter of 2017 (performed by 2,113 operators) to 3.01 per 100,000 beneficiaries in the last quarter of 2020 (performed by 2,415 operators) – a 4.8% relative increase per year (p=0.02). This growth was driven primarily by outpatient elective procedures, which represented the majority (85.0%) of all PVIs. Concurrent with this increase in PVI use, there was a significant decrease in complication rates (3.9% in 2017 vs 3.1% in 2020, p<.0001) and re-hospitalizations (8.8% vs 7.1%, p<0.001) at 30 days, with no significant change in mortality at 30 days (0.36% vs 0.40%, p=0.38). Bleeding was the most common peri-procedural complication (1.4%), followed by pericardial effusion requiring intervention (1.2%) and access site vascular complications (0.55%). Conclusions This large nationwide cohort study shows that the use of PVI has steadily increased in contemporary clinical practice. Despite the widespread adoption of this procedure by a growing number of operators, cumulative complication and re-hospitalization rates at 30 days have decreased over time, with stable and very low rates of short-term mortality – even among older patients, who are ordinarily considered to be at higher risk. These findings contrast with those from previously published studies of non-representative cohorts. Results from our study should reassure both patients and providers on the overall safety of PVI as an increasingly common first-line procedure for rhythm control. Forthcoming analyses will be finalized by the time of presentation to evaluate whether hospital and operator volume further influence procedural outcomes.Central Figure: PVI Trends and Outcomes

50-W vs 40-W During High-Power Short-Duration Ablation for Paroxysmal Atrial Fibrillation: A Multicenter Prospective Study

BackgroundHigh-power short-duration (HPSD) radiofrequency ablation of atrial fibrillation (AF) increases first-pass pulmonary vein isolation (PVI) and freedom from atrial arrhythmias while decreasing procedural time. However, the optimal power setting in terms of safety and efficacy has not been determined. ObjectivesThis study compared the procedural characteristics and clinical outcomes of 50-W vs 40-W during HPSD ablation of paroxysmal AF. MethodsPatients from the REAL-AF prospective multicenter registry (Real-World Experience of Catheter Ablation for Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation) undergoing HPSD ablation of paroxysmal AF, either using 50-W or 40-W, were included. The primary efficacy outcome was freedom from all-atrial arrhythmias. The primary safety outcome was the occurrence of any procedural complication at 12 months. Secondary outcomes included procedural characteristics, AF-related symptoms, and the occurrence of transient ischemic attack or stroke at 12 months. ResultsA total of 383 patients were included. Freedom from all-atrial arrhythmias at 12 months was 80.7% in the 50-W group and 77.3% in the 40-W group (Log-rank P = 0.387). The primary safety outcome occurred in 3.7% of patients in the 50-W group vs 2.8% in the 40-W group (P = 0.646). The 50-W group had a higher rate of first-pass PVI (82.3% vs 76.2%; P = 0.040) as well as shorter procedural (67 minutes [IQR: 54-87.5 minutes] vs 93 minutes [IQR: 80.5-111 minutes]; P < 0.001) and radiofrequency ablation times (15 minutes [IQR: 11.4-20 minutes] vs 27 minutes [IQR: 21.5-34.6 minutes]; P < 0.001) than the 40-W group. ConclusionsThere was no significant difference in freedom from all-atrial arrhythmias or procedural safety outcomes between 50-W and 40-W during HPSD ablation of paroxysmal AF. The use of 50-W was associated with a higher rate of first-pass PVI as well as shorter procedural times.

Left Atrial Posterior Wall Isolation with Pulsed Field Ablation in Persistent Atrial Fibrillation.

Left atrial posterior wall isolation (LAPWI) may improve rhythm control in addition to pulmonary vein isolation (PVI) in persistent atrial fibrillation (persAF) patients undergoing catheter ablation (CA). However, LAPWI may be challenging when using thermal energy sources. This study aimed to investigate the efficacy and safety of LAPWI performed by non-thermal pulsed field ablation (PFA) in CA for persAF. Consecutive persAF patients from two German centers were prospectively enrolled. There were two study cohorts: (1) the LAPWI cohort, which included PFA-guided (re-)PVI with LAPWI for first-time and/or repeat ablation procedures; and (2) a comparative persAF cohort with a PFA PVI-only approach without LAPWI for first-time ablation within the same timeframe. Patients were followed up by routine Holter ECGs. In total, 79 persistent AF patients were included in the study: 59/79 patients were enrolled in the LAPWI cohort, including 16/59 index (27%) and 43/59 repeat ablation procedures (73%). Sixteen patients (16/79; 21%) were in the PVI-only cohort without LAPWI. Of the patients treated with LAPWI, procedure time and fluoroscopy time was 91 ± 30 min and 15 ± 7 min, respectively. The acute PVI rate was 100% in all first-time ablation patients (32 patients (16 PVI only, 16 PVI plus LAPWI), 196/196 PVs). Of the 43 re-do patients in the LAPWI cohort, re-PVI was necessary in 33% (14/43) of patients (27 PVs; 1.9 PV per-patient); in 67% (29/43), all PVs were isolated, and antral ablation of the PV ostia was performed in 48% (14/29). LAPWI was performed successfully in all 59 (100%) patients of the LAPWI cohort. Two minor complications occurred. No esophageal lesion was detected in the LAPWI cohort (n = 33/59 (56%) patients underwent endoscopy). After 354 ± 197 days of follow-up, freedom from atrial arrhythmias was 79.3% (95-CI: 62-95%) in the complete LAPWI cohort (n = 14/59 (24%) on AAD: class Ic n = 9, class III n = 5). There was no difference regarding acute procedural and clinical outcome compared to the PVI-only cohort. LAPWI guided by PFA is feasible and safe in patients undergoing CA for persAF and shows favorable outcomes. In the context of durable PVI, PFA-guided LAPWI may be an effective adjunctive treatment option.

Liquid Nitrogen Cryoballoon Ablation System for Paroxysmal Atrial Fibrillation: A Multicenter, Prospective, Single-Arm Clinical Trial

BackgroundCryoballoon ablation (CBA) has emerged as an effective treatment for atrial fibrillation (AF). ObjectivesThis study sought to assess the performance of a novel liquid nitrogen–driven CBA system and evaluate its safety and efficacy in the treatment of drug-resistant paroxysmal atrial fibrillation (PAF). MethodsThis was a prospective multicenter single-arm clinical trial with 10 participating tertiary hospitals enrolling 176 patients with PAF. All participants received liquid nitrogen–driven CBA developed by the Cryofocus Medtech Company. Scheduled follow-up was performed before discharge and 3 months, 6 months, and 12 months after CBA. The primary endpoints were defined as 1) treatment success (freedom from antiarrhythmic drugs and atrial tachycardia at 12 months after CBA); and 2) immediate success rate of pulmonary vein isolation. The safety endpoint was the incidence of device- and procedure-related adverse events (AEs) and all-cause mortality. ResultsA total of 172 participants were included, with an average age of 59.22 ± 9.25 years and 99 (57.56%) of them men. Immediate success rate was 97.67% (95% CI: 94.15%-99.36%) and 12-month treatment success rate was 82.56% (95% CI: 76.89%-88.23%), including a late recurrence rate of 13.61%. Incidences of device- and procedure-related AEs were 2.27% and 25.00%, respectively. Phrenic nerve palsy (PNP) occurred in 6 patients, of which 5 recovered during follow-up. Although the incidence of total severe AEs was 17.05%, including an all-cause mortality of 0.57%, only 1 case of permanent PNP was related to the CBA procedure. ConclusionsThis premarketing prospective multicenter single-arm clinical trial demonstrated that the liquid nitrogen cryoablation system is safe and effective in the treatment of PAF.

Radiofrequency ablation of atrial fibrillation: A 14 years' experience at a tertiary care center in Thailand.

The result of atrial fibrillation (AF) ablation varies across centers. Most data are derived from the Western world, while data from Southeast Asian countries are lacking. We aimed to investigate the outcomes of AF ablation in Thailand. We performed a retrospective analysis of patients who underwent AF ablation in a tertiary care center, between the years 2006-2020. Details of AF ablation, including pulmonary vein isolation (PVI), and complex fractionated atrial electrogram (CFAE) ablation, were classified. The success rate of AF ablation is determined by freedom from AF beyond 3 months blanking period. Combined success rate of AF ablation was reported along with the success rate of each technique (PVI, CFAE, and combine PVI plus CFAE). We identified a total of 171 patients who underwent the first AF ablation. Ninety-four (55%) patients went through PVI, 55 (32%) patients for CFAE ablation, and 22 (13%) patients for PVI plus CFAE ablation. Overall freedom from AF was 73% at 12 months, 66% at 24 months, and 55% at 36 months. The success rate of PVI was 79% at 12 months, 74% at 24 months, and 59% at 36 months. The success rate of CFAE ablation was 63% at 12 months, 51% at 24 months, and 47% at 36 months. Catheter ablation of AF is proven safe and effective in Thai population.

High-Power Short-Duration Lesion Index-Guided Posterior Wall Isolation beyond Pulmonary Vein Isolation for Persistent Atrial Fibrillation.

Background: High-power short-duration (HPSD) radiofrequency (RF) ablation has been adopted to improve atrial fibrillation (AF) ablation. Although the role of HPSD is well-established in pulmonary vein isolation (PVI), fewer data have assessed the impact of HPSD when addressing extra-pulmonary veins (PVs) targets. Therefore, this study aims to determine the safety, effectiveness, and acute outcomes of HPSD lesion index (LSI)-guided posterior wall isolation (PWI) in addition to PVI as an initial strategy in persistent atrial fibrillation (Pe-AF). Methods: Consecutive patients who underwent ablation of Pe-AF in our center between August 2021 and January 2022 were retrospectively enrolled. All patients' ablation strategy was PVI plus PWI using HPSD LSI-guided isolation. RF parameters included 50 W targeting LSI values of ≥5 on the anterior part of the PVs and anterior roofline and ≥4 for the posterior PVs aspect, bottom line, and within the posterior wall (PW). We compared the LSI values with and without acute conduction gaps after the initial first-pass PWI. Left atrial mapping was performed with the EnSite X mapping system and a high-density multipolar Grid-shaped mapping catheter. We compared the procedural characteristics using HPSD (n = 35) vs. a control group (n = 46). Results: Thirty-five consecutive patients were included in the study. PWI on top of PVI was achieved in all cases in the HPSD group. First-pass PVI was achieved in 93.3% of PVs (n = 126/135). First-pass roofline block was obtained in most patients (n = 31, 88.5%), while first-pass block of the bottom line was only achieved in 51.4% (n = 18). There were no significant differences compared to the control group; first-pass PVI was achieved in 94.9% of PVs (n = 169/178), first-pass roofline block in 89.1%, and bottom-line in 45.6% of patients. To achieve complete PWI with HPSD, scattered RF applications within the PW were necessary. No electrical reconnection of the PW was found after adenosine administration and the waiting period. The procedure and RF times were significantly shorter in the HPSD group compared to the control group, with values of 116.2 ± 10.9 vs. 144.5 ± 11.3 min, and 19.8 ± 3.6 vs. 26.3 ± 6.4 min, respectively, p < 0.001. Fluoroscopy time was comparable between both groups. No procedural complications were observed. At the 12-month follow-up, 71.4% of patients remained free from AF, with no differences between the groups. Conclusions: HPSD LSI-guided PWI on top of PVI seems effective and safe. Compared to a control group, HPSD is associated with similar rates of first-pass PWI and PVI but with a shorter procedural and RF time.

Insight into contact force local impedance technology for predicting effective pulmonary vein isolation.

Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have the potential to act as a reliable predictor of the durability of the lesions created. We aimed to collect data on the procedural parameters affecting LI-guided ablation in a large multicenter registry. A total of 212 consecutive patients enrolled in the CHARISMA registry and undergoing their first pulmonary vein (PV) isolation for paroxysmal and persistent AF were included. In all, 13,891 radiofrequency (RF) applications of ≥3 s duration were assessed. The first-pass PV isolation rate was 93.3%. A total of 80 PV gaps were detected. At successful ablation spots, baseline LI and absolute LI drop were larger than at PV gap spots (161.4 ± 19 Ω vs. 153.0 ± 13 Ω, p < 0.0001 for baseline LI; 22.1 ± 9 Ω vs. 14.4 ± 5 Ω, p < 0.0001 for LI drop). On the basis of Receiver operating characteristic curve analysis, the ideal LI drop, which predicted successful ablation, was >21 Ω at anterior sites and >18 Ω at posterior sites. There was a non-linear association between the magnitude of LI drop and contact-force (CF) (r = 0.14, 95% CI: 0.13-0.16, p < 0.0001) whereas both CF and LI drop were inversely related with delivery time (DT) (-0.22, -0.23 to -0.20, p < 0.0001 for CF; -0.27, -0.29 to -0.26, p < 0.0001 for LI drop). An LI drop >21 Ω at anterior sites and >18 Ω at posterior sites predicts successful ablation. A higher CF was associated with an increased likelihood of ideal LI drop. The combination of good CF and adequate LI drop allows a significant reduction in RF DT. http://clinicaltrials.gov/, identifier: NCT03793998.

One-year outcomes in patients undergoing very high-power short-duration temperature-controlled ablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background The very high-power short-duration (vHPSD) temperature-controlled ablation (vHPSD) improves the efficiency of pulmonary vein isolation (PVI) procedures. Aims We evaluated the procedural and 12-months outcomes in atrial fibrillation (AF) patients undergoing PVI by means of vHPSD ablation. In patients with AF or atrial tachy-arrythmia (AT) recurrence undergoing a redo procedure the durability of the PVI was investigated. Methods Consecutive paroxysmal/persistent AF patients undergoing PVI with the vHPSD ablation strategy (90 W, for 4 s) were enrolled. The rate of PVI, first pass isolation, acute reconnection, and procedural complications were evaluated. Follow-up examinations and EKG were scheduled at 1,6, and 12 months. In case of AF/AT recurrence, patients underwent a redo procedure. Results Overall, 163 AF patients (29 persistent and 134 paroxysmal) were enrolled. The PVI was reached in 100% of patients (88% at first pass). The rate of acute reconnection was 2%. The radiofrequency, fluoroscopy and procedural times were respectively 5,5±1 min, 9±1 min and 75±20 min. No death, tamponade nor steam pops occurred, however 5 patients had vascular complications. The 12-months freedom from AF/AT recurrence was 84% in paroxysmal patients and 71% in persistent. Overall, 9 patients underwent a redo procedure, and in 4 all veins were still isolated, whereas in 5 pulmonary vein reconnections were found. The PVI durability was 83%. No overt complications were observed in the follow-up. Conclusions The vHPSD ablation represents an effective and safe ablation strategy to achieve PVI. The 12-months follow-up showed high freedom from AF/AT recurrence and a good safety profile.

Initial experience and early outcomes of posterior wall ablation using pulsed-field ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background The success rate of pulmonary vein isolation (PVI) is lower in patients with persistent compared to paroxysmal atrial fibrillation (AF). In patients with persistent AF, additional isolation of the posterior wall is under investigation to improve ablation success. Pulsed field ablation (PFA) might be superior to conventional methods for posterior wall isolation due to its safety profile and might allow for posterior wall ablation (PWA) rather than posterior wall isolation (PWI) based on its efficiency. Purpose To report our initial experience with PWA using a multipolar PFA catheter. Methods Consecutive patients with PWA during their first PFA procedure for AF between May 2021 and October 2022 at our institution were included. For PWA, the multipolar PFA ablation catheter was used in flower configuration only. With the wire in each of the pulmonary veins and the sheath angulated posteriorly, we first performed 2 x 2 sets of anchor lesions with the catheter rotated by ~30° between sets. Next, with the wire retracted back into the device, single sets of two applications were delivered in an overlapping fashion and without catheter rotation between lesion sets to cover the entire posterior wall between the superior and inferior pulmonary veins. Finally, completeness of PWA was verified by 3D electro-anatomical mapping. Results PWA using PFA was performed in 163 patients (mean age 67 years, 71% male). In 55 patients (34%), PWA was added to PVI during the first AF ablation procedure and the remaining 108 patients (66%) had undergone a median of two (interquartile range 1-3) previous AF ablation procedures using either cryoablation and/or radiofrequency ablation. Of all patients, 45 (28%) had paroxysmal, 93 (57%) persistent AF, and 22 patients (15%) left atrial reentry tachycardia. Median procedure duration and fluoroscopy time were 120 (70-190) min, and 18 (9-36) min, respectively. 3D-EAM showed no residual electrical signal (&amp;gt;0.05 mV) on the posterior wall at the end of the procedure in any patient. No cardiac tamponade, stroke, phrenic nerve injuries, atrio-esophageal fistula, or clinically manifest coronary spasm occurred. A repeat ablation was performed in seven patients (4%) and 3D-EAM showed persisting posterior wall isolation in six (86%) and recurrent roof dependent atrial flutter in one patient. Despite PWA, low-voltage signals were found in four (67%) cases on the superior aspect of the posterior wall. Conclusions Left atrial PWA can be performed safely and efficiently using PFA. Early data on the durability of PWA are promising. The impact of PWA on arrhythmia-free outcome needs to be evaluated in larger, prospective randomized trials.

Pulsed field ablation based pulmonary vein isolation utilizing a simplified approach

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety and efficacy advantages compared to standard ablation technologies. Purpose We aimed to develop a safe, effective and fast pulmonary vein isolation (PVI) utilizing a single shot PFA catheter via a single femoral vein puncture and a venous closure system approach. Methods Forty-eight consecutive AF patients underwent first-time PVI via PFA under deep sedation. A single ultrasound guided femoral vein puncture and a single transseptal puncture was utilized for left atrial access. After pulmonary vein (PV) angiography eight pulse trains (2kV/2.5 sec, bipolar, biphasic, each 4x basket/flower configuration) were delivered to each PV. Extra pulse trains in the flower configuration (8x) were added to the posterior wall for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with a s-shaped esophageal temperature probe. A venous closure system was utilized on the single access site. A Donati suture was performed. The pressure bandage was removed after 1h. Results Patients (mean age: 64 +/-11 years) presented with AF (paroxysmal 58% or persistent AF (42%). A total of 192 PV were identified and isolated via PFA (100%). A mean of 40 pulse trains for PVI and vWACA have been used. The mean procedural time was 27 +/- 7 minutes, the mean catheter dwell time was 14 +/- 6 minutes and the median fluoroscopy time was 6 +/- 2 minutes. No relevant esophagus temperature rise occurred. One patient (2%) experienced a transient phrenic nerve palsy which recovered until the end of the procedure. Two patients (4%) experienced a superficial bleeding which was treated by a figure of eight suture. No severed hematoma, transfusion or intervention was necessary. No pericardial effusion or tamponade occurred. Conclusion The combination of a single vein single transseptal puncture approach resulted in a 100% rate of acute PVI and an extraordinary fast procedure and dwell time. The rate of periprocedural complications was low.

Evaluation of laser balloon pulmonary vein isolation lesions during the acute and chronic phases using a high-resolution mapping system

Abstract Funding Acknowledgements Type of funding sources: None. Background Visually guided laser balloon (VGLB) has proven ample efficacy in achieving durable pulmonary vein (PV) isolation (PVI). Though the isolation area post-cryoballoon ablation has been reported to regress at the chronic phase, the shrinkage of the isolation area using VGLB during the chronic phase has not been described. Purpose This study aims to evaluate the differences in isolation areas created by VGLB between the acute and chronic phases using a high-resolution mapping system. Methods We assessed 26 patients who underwent a second procedure due to atrial fibrillation recurrence. Of them, 8 patients were treated with the third-generation VGLB and 18 patients were treated with the first-generation VGLB at the first session. In all patients, the voltage maps were created with high-resolution mapping catheters just after PVI (acute phase) and during the second session (chronic phase). With each map, the isolation area (&amp;lt;0.1mV) around the PV antrum was calculated. We validated the persistent durability of PVI, and then the regression of isolation lesions was analyzed in patients without any PV reconnections. Results The isolation areas were re-evaluated at 8.3±6.6 months after the initial procedure. Twenty patients (76.9%) preserved persistent isolation lesions of all four PVs. Of them, the reduction of the isolation areas on the left- and right-sided PV antrum were 1.6±3.2 cm² (10.7±23.1% of the acute phase) and 4.8±3.6 cm² (27.8±18.9%), respectively. The analysis of the results revealed that the isolation area of the right-sided PV antrum yielded statistical shrinkage during the chronic phase (P=0.001), even though the electrical isolation was preserved. Conclusion After VGLB ablation, the isolation area of the right-sided PV antrum significantly regressed at the chronic phase, while the rate of durable PVI was high in line with the previous report.

PO-01-120 SAFETY AND EFFICACY OF VERY HIGH-POWER SHORT-DURATION ABLATION FOR PULMONARY VEIN ISOLATION: 1-YEAR OUTCOME

The very high-power short-duration (vHPSD) temperature-controlled ablation (vHPSD) improves the efficiency of pulmonary vein isolation (PVI) procedures. We evaluated the procedural and 12-months outcomes in atrial fibrillation (AF) patients undergoing PVI by means of vHPSD ablation. In patients with AF or atrial tachy-arrythmia (AT) recurrence undergoing a redo procedure the durability of the PVI was investigated. Consecutive paroxysmal/persistent AF patients undergoing PVI with the vHPSD ablation strategy (90 W, for 4 s) were enrolled. The rate of PVI, first pass isolation, acute reconnection, and procedural complications were evaluated. Follow-up examinations and EKG were scheduled at 1,6, and 12 months. In case of AF/AT recurrence, patients underwent a redo procedure. Overall, 163 AF patients (29 persistent and 134 paroxysmal) were enrolled. The PVI was reached in 100% of patients (88% at first pass). The rate of acute reconnection was 2%. The radiofrequency, fluoroscopy and procedural times were respectively 5,5±1 min, 9±1 min and 75±20 min. No death, tamponade nor steam pops occurred, however 5 patients had vascular complications. The 12-months freedom from AF/AT recurrence was 86% both in paroxysmal and persistent patients. Overall, 9 patients underwent a redo procedure, and in 4 all veins were still isolated, whereas in 5 pulmonary vein reconnections were found. The PVI durability was 83%. No overt complications were observed in the follow-up. The vHPSD ablation represents an effective and safe ablation strategy to achieve PVI. The 12-months follow-up showed high freedom from AF/AT recurrence and a good safety profile.