Wide Area Circumferential Ablation Research Articles

Real-world data of radiofrequency catheter ablation in paroxysmal atrial fibrillation: Short- and long-term clinical outcomes from the prospective multicenter REAL-AF Registry

BackgroundThe safety and long-term efficacy of radiofrequency (RF) catheter ablation (CA) of paroxysmal atrial fibrillation (PAF) has been well established. Contemporary techniques to optimize ablation delivery, reduce fluoroscopy use, and improve clinical outcomes have been developed. ObjectiveThe purpose of this study was to assess the contemporary real-world practice approach and long-term outcomes of RF CA for PAF through a prospective multicenter registry. MethodsUsing the REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClincalTrials.gov Identifier: NCT04088071) Registry, patients undergoing RF CA to treat PAF across 42 high-volume institutions and 79 experienced operators were evaluated. The procedures were performed using zero or reduced fluoroscopy, contact force sensing catheters, wide area circumferential ablation, and ablation index as a guide with a target of 380–420 for posterior and 500–550 for anterior lesions. The primary efficacy outcome was freedom from all-atrial arrhythmia recurrence at 12 months. ResultsA total of 2470 patients undergoing CA from January 2018 to December 2022 were included. Mean age was 65.2 ±11.14 years, and 44% were female. Most procedures were performed without fluoroscopy (71.5%), with average procedural and total RF times of 95.4 ± 41.7 minutes and 22.1±11.8 minutes, respectively. At 1-year follow-up, freedom from all-atrial arrhythmias was 81.6% with 89.7% of these patients off antiarrhythmic drugs. No significant difference was identified comparing pulmonary vein isolation vs pulmonary vein isolation + ablation approaches. The complication rate was 1.9%. ConclusionRefinement of RF CA to treat PAF using contemporary tools, standardized protocols, and electrophysiology laboratory workflows resulted in excellent short- and long-term clinical outcomes.

Ostial vs. wide area circumferential ablation guided by the Ablation Index in paroxysmal atrial fibrillation.

Pulmonary vein isolation (PVI) guided by the Ablation Index (AI) has shown high acute and mid-term efficacy in the treatment of paroxysmal atrial fibrillation (AF). Previous data before the AI-era had suggested that wide-area circumferential ablation (WACA) was preferable to ostial ablation. However, with the use of AI, we hypothesize that ostial circumferential ablation is non-inferior to WACA and can improve outcomes in paroxysmal AF. Prospective, multicentre, non-randomized, non-inferiority study of consecutive patients were referred for paroxysmal AF ablation from January 2020 to September 2021. All procedures were performed using the AI software, and patients were separated into two different groups: WACA vs. ostial circumferential ablation. Acute reconnection, procedural data, and 1-year arrhythmia recurrence were assessed. During the enrolment period, 162 patients (64% males, mean age of 60 ± 11 years) fulfilled the study inclusion criteria-81 patients [304 pulmonary vein (PV)] in the WACA group and 81 patients (301 PV) in the ostial group. Acute PV reconnection was identified in 7.9% [95% confidence interval (CI), 4.9-11.1%] of PVs in the WACA group compared with 3.3% (95% CI, 1.8-6.1%) of PVs in the ostial group [P < 0.001 for non-inferiority; adjusted odds ratio 0.51 (95% CI, 0.23-0.83), P = 0.05]. Patients in the WACA group had longer ablation (35 vs. 29 min, P = 0.001) and procedure (121 vs. 102 min, P < 0.001) times. No significant difference in arrhythmia recurrence was seen at 1-year of follow-up [11.1% in WACA vs. 9.9% in ostial, hazard ratio 1.13 (95% CI, 0.44-1.94), P = 0.80 for superiority]. In paroxysmal AF patients treated with tailored AI-guided PVI, ostial circumferential ablation is not inferior to WACA with regard to acute PV reconnection, while allowing quicker procedures with less ablation time.

In Atrial Fibrillation, Omnipolar Voltage Maps More Accurately Delineate Scar Than Bipolar Voltage Maps

BackgroundOptimal method for voltage assessment in AF remains unclear. ObjectivesThis study evaluated different methods for assessing atrial voltage and their accuracy in identifying pulmonary vein reconnection sites (PVRSs) in atrial fibrillation (AF). MethodsPatients with persistent AF undergoing ablation were included. De novo procedures: voltage assessment in AF with omnipolar voltage (OV) and bipolar voltage (BV) methodology and BV assessment in sinus rhythm (SR). Activation vector and fractionation maps were reviewed at voltage discrepancy sites on OV and BV maps in AF. AF voltage maps were compared with SR BV maps. Repeat ablation procedures: OV and BV maps in AF were compared to detect gaps in wide area circumferential ablation (WACA) lines that correlated with PVRS. ResultsForty patients were included: 20 de novo and 20 repeat procedures. De novo procedure: OV vs BV maps in AF; average voltage 0.55 ± 0.18 mV vs 0.38 ± 0.12 mV; P = 0.002, voltage difference of 0.20 ± 0.07 mV; P = 0.003 at coregistered points and proportion of left atrium (LA) area occupied by low-voltage zones (LVZs) was smaller on OV maps (42.4% ± 12.8% OV vs 66.7% ± 12.7% BV; P < 0.001). LVZs identified on BV maps and not on OV maps correlated frequently to wavefront collision and fractionation sites (94.7%). OV AF maps agreed better with BV SR maps (voltage difference at coregistered points 0.09 ± 0.03 mV; P = 0.24) unlike BV AF maps (0.17 ± 0.07 mV, P = 0.002). Repeat ablation procedure: OV was superior in identifying WACA line gaps that correlated with PVRS than BV maps (area under the curve = 0.89, P < 0.001). ConclusionsOV AF maps improve voltage assessment by overcoming the impact of wavefront collision and fractionation. OV AF maps correlate better with BV maps in SR and more accurately delineate gaps on WACA lines at PVRS.

PO-02-122 TRACKING AND ABLATING THE MUSCLE SLEEVE/FASCICLE FOR PULMONARY VEIN ISOLATION

Pulmonary vein isolation (PVI) remains the cornerstone for atrial fibrillation (AF) ablation. However, it yields unsatisfactory outcomes requiring repeat procedures especially in persistent AF. Additional linear ablation, or of complex fractionated atrial electrograms, atrial rotors or ganglionated plexi prolongs procedure time and increases complications with small additional benefits. We evaluated the efficacy of a new method of tracking and ablating pulmonary vein (PV) muscle sleeve/fascicle followed by wide area circumferential ablation (WACA) as a method of treatment of AF. To track a muscle sleeve/fascicle, a Lasso catheter was placed into one PV and based on the electrograms pattern on the catheter, sites of exit of muscle sleeves/fascicles were determined along the wide area circumferential ablation (WACA) line. (Panel A of figure shows the electrogram pattern, which suggests two muscle fascicles [red and blue arrows]). Focal ablation at sites on the planned WACA line was then performed to interrupt the muscle sleeve/fascicle connection with atrium (Panel B and C of figure shows point ablation resulting in partial and complete isolation; black arrow marks the location of ablation catheter). The same method was repeated to the ipsilateral PV before full WACA of both PVs was commenced. The strategy was repeated on the contralateral PVs. Ablation of these fascicle-atrium connections resulted in PVI isolation before WACA was completed in all 18 patients. Intravenous adenosine was used at the end to elicit dormant PV connections. We schematically labeled the areas around the PVs into zones and summarized the location of these muscle fascicles in each patient. (Panel D; each dot represents a fascicle and color matches with the PV with which it is associated). Eighteen patients (61±11 years old, 56% male) with AF (12 persistent {67%}) were analyzed in this study. Fascicles were identified in all patients and focal ablation of fascicles resulted in isolation of the PVs. In addition to PVI, 8 had Cavotricuspid isthmus ablation, 1 for right focal atrial tachycardia (AT), one left focal AT, and 1 for biatrial reentrant AT. With a follow-up of 155 ±120 days, 83% of paroxysmal and 75% of persistent AF remained in sinus rhythm. Left atrial dwell time for PVI alone was less than 2 hrs and no complications were seen. The tracking and ablating muscle sleeve/fascicle before performing WACA is a strategy with outcomes superior to previously reported in literature.

Standard vs Augmented Ablation of Paroxysmal Atrial Fibrillation for Reduction of Atrial Fibrillation Recurrence

Recurrent atrial fibrillation (AF) commonly occurs after catheter ablation and is associated with patient morbidity and health care costs. To evaluate the superiority of an augmented double wide-area circumferential ablation (WACA) compared with a standard single WACA in preventing recurrent atrial arrhythmias (AA) (atrial tachycardia, atrial flutter, or atrial fibrillation [AF]) in patients with paroxysmal AF. This was a pragmatic, multicenter, prospective, randomized, open, blinded end point superiority clinical trial conducted at 10 university-affiliated centers in Canada. The trial enrolled patients 18 years and older with symptomatic paroxysmal AF from March 2015 to May 2017. Analysis took place between January and April 2022. Analyses were intention to treat. Patients were randomized (1:1) to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA or an augmented double WACA. The primary outcome was AA recurrence between 91 and 365 days postablation. Patients underwent 42 days of ambulatory electrocardiography monitoring after ablation. Secondary outcomes included need for repeated catheter ablation and procedural and safety variables. Of 398 patients, 195 were randomized to the single WACA (control) arm (mean [SD] age, 60.6 [9.3] years; 65 [33.3%] female) and 203 to the double WACA (experimental) arm (mean [SD] age, 61.5 [9.3] years; 66 [32.5%] female). Overall, 52 patients (26.7%) in the single WACA arm and 50 patients (24.6%) in the double WACA arm had recurrent AA at 1 year (relative risk, 0.92; 95% CI, 0.66-1.29; P = .64). Twenty patients (10.3%) in the single WACA arm and 15 patients (7.4%) in the double WACA arm underwent repeated catheter ablation (relative risk, 0.72; 95% CI, 0.38-1.36). Adjudicated serious adverse events occurred in 13 patients (6.7%) in the single WACA arm and 14 patients (6.9%) in the double WACA arm. In this randomized clinical trial of patients with paroxysmal AF, additional ablation by performing a double ablation lesion set did not result in improved freedom from recurrent AA compared with a standard single ablation set. ClinicalTrials.gov Identifier: NCT02150902.

Inability to perform 'en bloc' pulmonary vein isolation requiring ablation of the intervenous carina increases recurrence of atrial fibrillation: A meta-analysis.

Failure to isolate ipsilateral pulmonary veins (PV) "en bloc" by wide-area circumferential ablation (WACA) may necessitate ablation at the intervenous carina. It is unknown how this scenario impacts rates of atrial fibrillation (AF) recurrence. A standard random-effect meta-analysis of randomized or observational studies were performed, where the outcome of first-time AF ablation was reported in patients with "en bloc" isolation of PVs by WACA as compared with those in whom ablation at the intervenous carina was needed after WACA to achieve complete isolation. A total of five single-center, observational studies (N=1185) and one, multi-center randomized trial (N=234) were enrolled. PV isolation could be achieved by WACA "en bloc" in 902/1419 (63.6%) cases. The rest required additional ablation at one or both of the left and right intervenous carinas to achieve isolation. The follow-up time after ablation ranged from 1 to 2 years in the included trials. The incidence of AF recurrence proved to be significantly lower in patients with successful "en bloc" isolation compared to those requiring carina ablation(s) to achieve complete bilateral PV isolation (MH-OR 1.89, 95% CI 1.42-2.53, p<.01) CONCLUSION: This present meta-analysis demonstrates a lower arrhythmia recurrence rate in patients with bilateral "en bloc" isolation, as compared to those who needed additional carina ablation for complete PVI. Therefore, it is imperative that every effort be made to isolate ipsilateral PVs "en bloc" during PVI.

Posterior wall isolation in persistent atrial fibrillation. Long-term outcomes of a repeat procedure strategy.

Posterior wall isolation (PWI) added to pulmonary vein isolation (PVI) is increasingly used in ablation for persistent atrial fibrillation (PeAF) despite limited evidence of clinical benefit. We investigated the 5-year outcomes of a PVI + PWI ablation strategy with mandatory repeat procedures in PeAF. Twenty-four patients with PeAF participated in this single-arm prospective study and underwent radiofrequency ablation (RFA) with wide area circumferential ablation (WACA), roof, and inferior lines for PVI + PWI which was reinforced if required during mandated repeat procedures after 6months. Then, patients were followed for 60months using continuous heart rhythm monitoring by implanted cardiac monitors (ICM) and atrial fibrillation effect on quality-of-life scoring (AFEQT; range: 20-100 points) for the initial 30months. ICM-verified cumulated AF recurrence was 54% after 30months but the ensuing AF burden was only median 0‰ [0 to 4.8‰] overall and 1‰ [0 to 8 ‰] among patients with any recurrence. AFEQT scores increased from baseline 60 points [48 to 72] to 93 points [84 to 96] at repeat procedures P < 0.0001 and further to 96 points [93 to 99] P = 0.03 after 30months. After 60months, at least one episode of AF had been documented in 63% and two patients (8%) were in permanent AF. Reinforced PVI + PWI was associated with low long-term AF burden and corresponding improvements in quality-of-life. Reinforced (or durable) PVI + PWI appears to be a promising strategy to treat PeAF. ClinicalTrials.gov. Identifier: NCT05045131.

Characterization of circumferential antral pulmonary vein isolation areas resulting from pulsed-field catheter ablation.

The cornerstone of pulmonary vein (PV) isolation (PVI) is a wide-area circumferential ablation (WACA) resulting in an antral PVI area. Pulsed-field ablation (PFA) is a new nonthermal 'single-shot' PVI technique resulting in well-characterized posterior isolation areas. However, information on circumferential PVI area is lacking. Thus, we sought to characterize the circumferential antral PVI areas after PFA-PVI. Atrial fibrillation (AF) patients underwent fluoroscopy-guided PVI with a pentaspline PFA catheter. Ultra-high-density voltage maps using a 20-polar circular mapping catheter were created before and immediately after PVI to identify and quantify (i) insufficient isolation areas per antral PV segment (10-segment model) and (ii) enlarged left atrial (LA) isolation areas (beyond the antral PV segments) per LA region (8-region model). The PFA-PVI with pre- (5469 ± 1822 points) and post-mapping (6809 ± 2769 points) was performed in 40 consecutive patients [age 62 ± 6 years, 25/40 (62.5%) paroxysmal AF]. Insufficient isolation areas were located most frequently in the anterior antral PV segments of the left PVs (62.5-77.5% of patients) with the largest extent (median ≥0.4 cm2) located in the same segments (segments 2/5/8). Enlarged LA isolation areas were located most frequently and most extensively on the posterior wall and roof region (89.5-100% of patients; median 1.1-2.7 cm2 per region). Fluoroscopy-guided PFA-PVI frequently results in insufficient isolation areas in the left anterior antral PV segments and enlarged LA isolation areas on the posterior wall/roof, which both may be extensive. To optimize the procedure, full integration of PFA catheter visualization into three-dimensional-mapping systems is needed.

Distinct propagation patterns of right pulmonary veins through multiple epicardial connections during right atrial pacing and sinus rhythm

A 47-year-old man with symptomatic paroxysmal atrial fibrillation (AF) underwent AF ablation. Activation maps during right atrial pacing and sinus rhythm before the ablation revealed distinctive left atrial (LA) propagations with multiple LA breakthrough sites via epicardial connections. A wide area circumferential ablation was not able to achieve a right pulmonary vein (RPV) isolation and required an inner PV ablation to isolate the RPV. Activation maps during different rhythms before the ablation may be helpful to unmask multiple epicardial connections between the RPV and right atrium.

The Impact of Radiofrequency Wide Circumferential Pulmonary Vein Isolation on Left Atrial Geometry in Patients with Recurrent Atrial Fibrillation

Purpose: The aim of the study was to investigate the effect of wide area circumferential radiofrequency catheter ablation (WACA) pulmonary vein isolation on left atrium (LA) geometry. Methods: Seventy-one patients underwent WACA, for recurrent paroxysmal (n = 31) and persistent (n = 40) atrial fibrillation (AF). A three-dimension rotational angiography of the LA was obtained immediately prior to index and repeat procedure. Results: Significant reduction of LA volume (65.6 ± 14 mL/m² vs. 62.2 ± 15 mL/m², p < 0.001) and surface (74.4 ± 11.2 vs. 70.4 ± 11.2 cm²/m², p < 0.001) was noted. LA sphericity increased significantly (82 ± 2% vs. 83 ± 2%, p = 0.004) in all 71 patients. Patients with paroxysmal AF showed significant reduction of LA volume (121.8 ± 25.7 vs. 116 ± 32 mL, p = 0.008) and increase of LA sphericity (82.3 ± 2.1 vs. 83.1 ± 2%, p = 0.009). Patients with persistent AF showed significant decrease of LA volume (133.5 ± 32 vs. 126 ± 32 mL, p = 0.005) and LA surface area (76.3 ± 12.3 vs. 71.8 ± 12.4 cm²/m², p = 0.005). LA sphericity (82.4 ± 2.8 vs. 83 ± 2.4%, p = ns) remained unchanged. Conclusions: WACA results into significant reduction of LA volume and surface area. Increased LA sphericity is observed in paroxysmal AF only.

Posterior wall isolation in persistent atrial fibrillation feasibility, safety, durability, and efficacy.

IntroductionPosterior wall isolation (PWI) added to pulmonary vein isolation (PVI) is increasingly used despite limited evidence of clinical benefit. We investigated the feasibility, durability, and efficacy of index‐procedure PVI + PWI radio frequency ablation (RFA) in patients with persistent atrial fibrillation (PeAF).Methods and ResultsTwenty‐four patients with PeAF participated in the prospective PeAF‐Box study and underwent RFA with wide area circumferential ablation, roof‐ and inferior lines to achieve PVI + PWI at index procedure. Follow‐up included monitoring by an implantable cardiac monitor, esophagoscopy and mandated invasive lesion‐reassessment at 6 months. PWI was achieved at minor procedural cost in all patients following PVI. In 33% of patients a median of three ablations in the narrow zone between the center of the posterior wall (PW) and the posterior right carina was pivotal for swift achievement of PWI. At the 6‐month reassessment procedure 85% (95% confidence interval [CI]: 77%–92%) of pulmonary veins (PVs) and 46% (95% CI: 26%–67%) of PWs remained durably isolated. AF recurred in 25% and was associated with PV‐reconnection (p = .02) but not PW‐reconnection (p = .27). AF‐burden was 0% (interquartile range [IQR]: 0%–0%) overall and after recurrence 1% (IQR: 0%–7%).ConclusionIndex procedure PVI + PWI for PeAF was feasible when recognizing that limited ablation in a PW center‐to‐right‐carina zone was required in a subset of patients. Despite limited chronic PWI durability this strategy was followed by low AF‐burden. A PVI + PWI strategy appears promising in ablation for PeAF.

Areas of minimal generator impedance drop during the index atrial fibrillation ablation correlate with pulmonary vein reconnection sites despite adopting the CLOSE protocol

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulmonary vein (PV) isolation is the cornerstone of atrial fibrillation (AF) management. However, AF recurrence is extremely common after a single procedure. The CLOSE protocol, which is the standardisation of radiofrequency catheter ablation by delivering a point-by-point lesion set defined by ablation index (AI), has demonstrated 80% freedom of AF. Yet PV reconnection is still up to 38% in these patients (1). A small decrease in generator impedance (GI), which is not part of the AI algorithm, has been associated with recovery of PV conduction. Purpose The study aimed to identify whether lesions having a poor impedance drop (PID) after wide area circumferential ablation (WACA) are associated with PV reconnection, despite adopting to the CLOSE protocol. Methods 120 consecutive patients who had both the index (i-AFA) and redo AF ablations (r-AFA) due to AF recurrence at our centre from Jan 2018 to Jun 2021 were screened. 18 patients who had WACA around PVs using high power (40 to 50W) with a minimum AI of 400, whilst adhering the CLOSE protocol during the i-AFA, and who had evidence of PV reconnection during r-AFA, were included in the study. Ones who had left atrial (LA) substrate or cryoablation were excluded. GI was measured between the skin patch and ablation catheter. CARTO® system was used to create LA electroanatomical maps (EAMs) and register ablation lesions. Each WACA around PVs was divided into eight anatomical segments (Figure). PID was defined as an impedance change of &amp;lt;8Ω, based on previous studies (2). These lesions were identified and categorised to the relevant anatomical segment in the i-AFA. Locations of the discrete ablation lesions that re-isolated PVs during the r-AFA, were used as a surrogate to denote areas of PV reconnection. These were also spatially matched to the relevant anatomical segment. Each EAM was reviewed by two electrophysiologists. Results 30 out of the 36 WACAs (83%) and on average, at least 2 segments per WACA (2.6; 95% confidence interval (CI): 2.2-3.1) had reconnected. 54% of the reconnected segments had at least one lesion with PID. Having a lesion with PID in a PV segment in the i-AFA was significantly associated with evidence of PV reconnection in the same segment in the r-AFA (odds ratio: 2.1 [95% CI: 1.3-3.6; p&amp;lt;0.01]). Right posterior/inferior (56%) and left anterior/superior (50%) PV segments were the most common areas to reconnect and these areas were also associated with a higher incidence of PID lesions in the i-AFA (94% and 67%, respectively). Conversely, 80% of segments with all lesions having an impedance drop of ≥8Ω had no PV reconnection. Conclusion Lesions with PID in the i-AFA could impact PV reconnection, despite lesion contiguity and an adequate AI. Identifying and targeting these areas of PID, in addition to the CLOSE protocol, could potentially reduce AF recurrence. Prospective studies are needed to validate this hypothesis and its safety.

Evaluation of myocardial injury induced by different ablation approaches in atrial fibrillation patients

Abstract Funding Acknowledgements Type of funding sources: None. Background To evaluate myocardial injury in Atrial Fibrillation (AF) patients undergoing High Power Short Duration radiofrequency (HPSD) and visually guided Laser Balloon Ablation (LBA). Methods and results In this single center registry we prospectively enrolled 40 patients (67% male), mean age 63±9, with paroxysmal or persistent AF (see table I). The ablation target has been the pulmonary vein isolation (PVI) with LBA and wide area circumferential ablation (WACA) with HPSD. 6 and 18 hours post-procedure samples of high sensitive cardiac troponin I (cTnI) were collected. The results show not significant differences in target population and no significant differences in high sensitive cardiac troponin I (cTnI pg/ml) levels at 6h (HPSD cTnI =806±496 pg/ml vs laser cTnI = 664±339 pg/ml p=0.17) and 18 hours after ablation (HPSD cTnI =833±540 pg/ml vs laser cTnI = 1081±962 pg/ml p=0.07). Conclusion These results indicate that myocardial injury induced by HPSD and LBA at 6 and 18 hours after procedure are similar targeting WACA and PVI respectively. This registry is ongoing to evaluate freedom from AF at 12 months follow up.

Characterization of the circumferential cevel of the pulmonary vein isolation area using pulsed-field catheter ablation: Spatial distribution and extent of insufficient and excessive isolation areas

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The cornerstone of pulmonary vein isolation (PVI) is a wide area circumferential ablation (WACA) resulting in an isolation area encompassing the PV antrum. Pulsed field ablation (PFA) is a new non-thermal "single-shot" PVI device with promising success rates. However, the circumferential level of its PV isolation area is still unknown. Objective To characterize the circumferential acute PV isolation area by assessing the spatial distribution (qualitative analysis) and extent (quantitative analysis) of insufficient PV antral and excessive LA isolation areas. Methods In this study, patients with paroxysmal or persistent atrial fibrillation (AF) underwent PVI with a pentaspline PFA catheter. Before and immediately after PVI, ultra-high-density (UHD) voltage maps using a 20-polar circular mapping catheter were created. The insufficient isolations areas per antral PV segment (10-segment model) and excessive isolation areas per LA region (8-region model) were quantified. Results Between November – December 2021, in forty consecutive patients (age 62 ± 6 years, 28/40 [70%] male, LA 41 ± 4 mm) acute PVI using PFA was achieved and pre (5469 ± 1822 points) and post mapping (6809 ± 2769 points) was performed. The anterior antral PV segments of the left PVs were the most frequent locations of insufficient isolation areas (Table 1, Figure 1). The largest extent of insufficient isolation areas at the PV antral level was located again on the anterior parts of both left PVs (Figure 2A), but also in the anterior lower segment of the right inferior PV (Figure 2B). The posterior wall and roof region of both LA sides were the most frequent locations of excessive isolation areas (Figure 4). The extent of this excessive isolation at the roof and the posterior wall on both LA sides even resulted in a connection of the both-sided low voltage areas in 18% and 8%, respectively. Conclusion When using PFA to achieve a circumferential antral PVI, efforts should be made to enhance anterior antral PV segment and prevent excessive posterior wall and roof ablation. For further optimizing the procedure, full integration of PFA catheter visualization into 3D-mapping systems is needed.

Wide area circumferential ablation for pulmonary vein isolation using radiofrequency versus laser balloon ablation.

BackgroundPersistent atrial fibrillation (AF) is associated with high recurrence rates of AF and atypical atrial flutters or tachycardia (AFT) postablation. Laser balloon (LB) ablation of the pulmonary vein (PV) ostia has similar efficacy as radiofrequency wide area circumferential ablation (RF‐WACA); however, an approach of LB wide area circumferential ablation (LB‐WACA) may further improve success rates.ObjectiveTo evaluate freedom from atrial tachyarrhythmia (AFT/AF) recurrence postablation using RF‐WACA versus LB‐WACA in persistent AF patients.MethodsThis was a retrospective multicenter study. Patients were followed for up to 24 months via office visits, Holter, and/or device monitoring. The primary endpoint was freedom from AFT/AF after a single ablation procedure. Secondary endpoints included freedom from AF, freedom from AFT, first‐pass isolation of all PVs, and procedural complications.ResultsTwo hundred and four patients were studied (LB‐WACA: n = 103; RF‐WACA: n = 101). Patients’ baseline characteristics were similar except patients in the RF‐WACA group were older (64 vs. 68, p = .03). First‐pass isolation was achieved more often during LBA (LB‐WACA: 88% vs. RF‐WACA 75%; p = .04). Procedure (p = .36), LA dwell (p = .41), and fluoroscopy (p = .44) time were similar. The mean follow‐up was 506 ± 279 days. Sixty‐six patients had arrhythmic events including 24 AFT and 59 AF recurrences. LB‐WACA group had higher arrhythmia‐free survival (p = .009) after single ablation procedures. In the multivariate Cox regression model, RF‐WACA was associated with a higher recurrence of AFT compared with LB‐WACA (Adjusted HR 3.16 [95% CI: 1.13–8.83]; p = .03).ConclusionsLB‐WACA was associated with higher freedom from atrial arrhythmias mostly driven by the lower occurrence of AFT compared with RF‐WACA.

Persistent Carina Conduction after Wide Area Circumferential Ablation is Associated with Inadequate Lesion Creation During Pulmonary Vein Isolation

Persistent Carina Conduction after Wide Area Circumferential Ablation is Associated with Inadequate Lesion Creation During Pulmonary Vein Isolation

High-Frequency, Low-Tidal-Volume Mechanical Ventilation Safely Improves Catheter Stability and Procedural Efficiency During Radiofrequency Ablation of Atrial Fibrillation

High-Frequency, Low-Tidal-Volume Mechanical Ventilation Safely Improves Catheter Stability and Procedural Efficiency During Radiofrequency Ablation of Atrial Fibrillation

Augmented wide area circumferential catheter ablation for reduction of atrial fibrillation recurrence (AWARE) trial: Design and rationale

Recurrence of atrial fibrillation (AF) after a pulmonary vein isolation procedure is often due to electrical reconnection of the pulmonary veins. Repeat ablation procedures may improve freedom from AF but are associated with increased risks and health care costs. A novel ablation strategy in which patients receive "augmented" ablation lesions has the potential to reduce the risk of AF recurrence. The Augmented Wide Area Circumferential Catheter Ablation for Reduction of Atrial Fibrillation Recurrence (AWARE) Trial was designed to evaluate whether an augmented wide-area circumferential antral (WACA) ablation strategy will result in fewer atrial arrhythmia recurrences in patients with symptomatic paroxysmal AF, compared with a conventional WACA strategy. The AWARE trial was a multicenter, prospective, randomized, open, blinded endpoint trial that has completed recruitment (ClinicalTrials.gov NCT02150902). Patients were randomly assigned (1:1) to either the control arm (single WACAlesion set) or the interventional arm (augmented- double WACA lesion set performed after the initial WACA). The primary outcome was atrial tachyarrhythmia (AA; atrial tachycardia [AT], atrial flutter [AFl] or AF) recurrence between days 91 and 365 post catheter ablation. Patient follow-up included 14-day continuous ambulatory ECG monitoring at 3, 6, and 12 months after catheter ablation. Three questionnaires were administered during the trial- the EuroQuol-5D (EQ-5D) quality of life scale, the Canadian Cardiovascular Society Severity of Atrial Fibrillation scale, and a patient satisfaction scale. The AWARE trial was designed to evaluate whether a novel approach to catheter ablation reduced the risk of AA recurrence in patients with symptomatic paroxysmal AF.

B-PO04-107 INCIDENCE AND CHARACTERISTICS OF CARINAL ABLATION IN PULMONARY VEIN ISOLATION

Radiofrequency ablation (RFA) of the intervenous carinae may be needed for pulmonary vein isolation (PVI) during catheter ablation of atrial fibrillation (AF), possibly due to epicardial connections. We sought to evaluate incidence and characteristics of carinal RFA needed to achieve PVI. A retrospective analysis of 200 AF RFA cases at the Ohio State University Hospital using CARTO 3 (Biosense Webster, Inc.[BSW]), a contact force catheter, real-time lesion quality assessment tool (Ablation Index [AI]) was performed using case data stored on cloud-based storage (CARTONET™, BSW). Each lesion was automatically annotated and regionally assigned to one of the 10 left atrial (LA) anatomical segments (anterior, posterior, inferior, roof, and carina on each side). A total of 22013 lesions were analyzed, including 1302 right and 671 left carinal lesions. PVI was achieved in all 200 patients (50% paroxysmal [PAF] and 50% persistent AF [PersAF]). Carinal RFA was performed only if PVI was not initially achieved after wide area circumferential ablation (WACA) of the PV antra. Ipsilateral only carinal RFA was required in 65 (32.5%) right and 32 (16%) left WACA’s respectively, while 48 (24%) required bilateral carinal RFA and no carinal RFA was required in 55 (27.5%). The right carina required significantly more RFA’s than the left carina (6.5 ± 8.3 vs. 3.4 ± 5.8 [p< 0.001]). There was no difference between the right and left carinae in the contact force (14.2 ± 5.6 g vs 12.5 ± 5.4 g), power (32.2 ± 7.8 W vs. 32.3 ± 7.1 W) or AI (336.8 ±57.4 vs. 327.1 ± 63.1). PersAF required significantly more carinal RFA lesions than PAF (12.3 ± 10.1 vs. 7.45 ± 11.3 [p=0.002]). In 134 patients with carinal RFA and complete AI data, the anterior LA, posterior LA, and the carinae received significantly different levels of AI (429.1 ± 84.8 vs 315.1 ± 48.7 vs. 222.2 ± 79.9 respectively [p< 0.001)]. Carinal RFA was frequently needed for PVI. More RFA in the carinae were needed in right than left PVs consistent with known prevalence of epicardial connections. Interestingly, more carinal RFA was needed in PersAF than PAF. The mean AI in the carinae was significantly lower than AI in anterior and posterior LA. These data may allow more efficient planning of lesion delivery.

Predictors of clinical success after paroxysmal atrial fibrillation catheter ablation

Contact force (CF) guided ablation of paroxysmal atrial fibrillation (PAF) with stable catheter-tissue contact optimizes clinical success and may increase an operator's ability to achieve pulmonary vein isolation (PVI) in a single encirclement. First pass PVI reduces procedure time but the relationship with long term clinical success is not well understood. This study evaluated patient characteristics and procedural details as predictors of 1-year clinical success after PAF ablation, including first pass isolation. Consecutive de novo PAF ablations were performed with a porous tip CF catheter in 2017 and 2018. All ablations used wide-area circumferential ablation, with first pass isolation captured separately for the left and right pulmonary veins (PVs). CF was held between 10 and 20 g and the catheter was moved every 10-20 s. Radiofrequency energy was set at 40-45 W throughout the atrium. Patient characteristics and procedural details were tested for association with clinical success, defined as freedom from recurrent atrial tachyarrhythmia through 1 year. A total of 404 patients were included in the study. Clinical success at 1 year was 86.6%. Achieving first pass isolation on at least one ipsilateral PV pair was the most significant predictor of clinical success (p = .0126). After controlling for first pass isolation, only recurrence within the 90-day blanking period was independently predictive (p = .0015). First pass isolation was not associated with early recurrence (p = .2454). In a real-world setting, first pass isolation was highly predictive of 12-month clinical success after CF-guided ablation in a PAF population.