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In this study, the authors sought to investigate the added value of vein of Marshall ethanol infusion (VOMEt) as first step in facilitating radiofrequency (RF)-guided mitral isthmus (MI) block.Achieving MI block with the use of RF ablation is challenging.Seventy patients planned for MI ablation were randomized 1:1 to VOMEt as a first step preceding RF (endocardial and epicardial, VOMIn VOMVOMEt as a first step in RF-guided MI line ablation significantly reduced the number of RF applications needed to achieve MI block, even if the sequence of the ablation steps did not affect the final incidence of block. (Evaluation of Vein of Marshall Ethanol Infusion During Left Atrial Linear Ablation in Patients With Persistent Atrial Fibrillation [MARSHALINE]; NCT04124328).

Background: The inspIRE study (Study for Treatment of Paroxysmal Atrial Fibrillation [PAF] by Pulsed Field Ablation [PFA] System With Irreversible Electroporation [IRE]) evaluated safety and effectiveness of a fully integrated biphasic pulsed field ablation (PFA) system with a variable-loop circular catheter for the treatment of drug-refractory paroxysmal atrial fibrillation.Methods: Subjects underwent pulmonary vein (PV) isolation with the PFA system, using at least 12 applications per vein; adenosine/isoproterenol was administered to confirm entrance block. Wave I assessed initial safety, including for esophageal lesions, silent cerebral lesions, and PV stenosis. Wave II (pivotal phase) tested (1) primary safety, incidence of early-onset primary adverse events, and (2) primary effectiveness, confirmed PV isolation with freedom from documented atrial arrhythmia at 12 months. The study design specified an interim analysis to determine early success once 30 subjects reached the 12-month follow-up and all subjects reached 3-month follow-up.Results: Across 13 centers in Europe/Canada, 226 subjects were enrolled, met criteria for safety and effectiveness evaluations, and received PFA (Wave I, 40; Wave II, 186). Wave I demonstrated no esophageal thermal lesions or PV stenosis. Among 39 subjects with cerebral magnetic resonance imaging, silent cerebral lesions were detected in 4 of the first 6 subjects, after which workflow enhancements, including a 10-second pause between PFA applications, were implemented; subsequently, only 4 of 33 subjects had silent cerebral lesions. In the Wave II phase, no primary adverse events were reported. Upon declaring early success, 83 subjects reached 12-month follow-up. With 100% entrance block, PV isolation without acute reconnection was achieved in 97.1% of targeted veins. For Wave II, the primary effectiveness end point per Kaplan-Meier at the time of interim analysis was 70.9%; 12-month freedom from symptomatic atrial fibrillation/atrial flutter/atrial tachycardia recurrence and repeat ablation was 78.9% and 92.3%, respectively. Total procedure and transpired PFA times were 70.1 +/- 27.7 and 26.7 +/- 14.0 minutes, respectively.Conclusions: The inspIRE trial confirmed the safety and effectiveness of the novel mapping-integrated PFA system. The authors would like to express their deepest gratitude to all investigators, including coinvestigators and guest operating investigators. They wish to thank the following individuals for their support in trial design, execution, statistical analysis, medical writing, and additional value to developing the manuscript: Carmen Rousseeuw, Sarah Rabau, Liesbeth Vanderlinden, Lee Ming Boo, Christina Kaneko, Jaclyn Alcazar, Tara Gomez, Tiffany Tan, Melissa Mert, Guixia Huang, Xiaoxue Gu, Puneet Jatana, Rebecca Beals, and Dror Berman (all employees of Biosense Webster, Inc.). Michelle Hughes, Bsc, with Lumanity Communications Inc (Yardley, PA), provided medical writing and editorial support, in accordance with Good Publication Practice guidelines, which were funded by Biosense Webster, Inc, under direction of the authors.

INTRODUCTION During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics confirms LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. METHODS Thirty patients (mean age 76 ± 14 years) were implanted with a stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (comparison-group) conventional implantation with interrupted unipolar pacing was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (uninterrupted-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were evaluated. RESULTS In the comparison-group, LS and CP-pacing impedances were highly correlated (R2 =0.95, p

Aims Very high-power short-duration (vHPSD) via temperature-controlled ablation (TCA) is a new modality to perform radiofrequency pulmonary vein isolation (PVI), conceivably at the cost of a narrower safety margin towards the oesophagus. In this two-centre trial, we aimed to determine the safety of vHPSD-based PVI with specific emphasis on silent oesophageal injury. Methods and results Ninety consecutive patients with atrial fibrillation (AF) underwent vHPSD-PVI (90 W, 3–4 s, TCA) using the QDOT MICRO catheter, in conjunction with the nGEN (Bad Neustadt, n = 45) or nMARQ generator (Bruges, n = 45). All patients underwent post-ablation oesophageal endoscopy. Procedural parameters and complications were recorded. A subgroup of 21 patients from Bad Neustadt underwent cerebral magnetic resonance imaging (cMRI) to detect silent cerebral events (SCEs). Mean age was 67 ± 9 years, 59% patients were male, and 66% patients had paroxysmal AF. Pulmonary vein isolation was obtained in all cases after 96 ± 29 min. No steam pop, cardiac tamponade, stroke, or fistula was reported. None of the 90 patients demonstrated oesophageal ulceration (0%). Charring was not observed in the nMARQ cohort (0% vs. 11% in the nGEN group). In 5 out of 21 patients (24%), cMRI demonstrated SCE (exclusively nGEN cohort). Conclusion Temperature-controlled vHPSD catheter ablation allows straightforward PVI without evidence of oesophageal ulcerations or symptomatic complications. Catheter tip charring and silent cerebral lesions when using the nGEN generator have led to further modification.

ObjectivePulmonary vein isolation (PVI) guided by a standardised CLOSE (contiguous optimised lesions) protocol has been shown to increase clinical success after catheter ablation for paroxysmal atrial fibrillation (PAF). This study analysed healthcare utilisation and quality of life (QOL) outcomes from a large multicentre prospective study, measured association between QOL and atrial fibrillation (AF) burden and identified factors associated with lack of QOL improvement.MethodsCLOSE-guided ablation was performed in 329 consecutive patients (age 61.4 years, 60.8% male) with drug-refractory PAF in 17 European centres. QOL was measured at baseline and 12 months post-ablation via Atrial Fibrillation Effect on QualiTy of Life Survey (AFEQT) and EuroQoL EQ-5D-5L questionnaires. All-cause and cardiovascular hospitalisations and cardioversions over 12 months pre-ablation and post-ablation were recorded. Rhythm monitoring included weekly and symptom-driven trans-telephonic monitoring, plus ECG and Holter monitoring at 3, 6 and 12 months. AF burden was defined as the percentage of postblanking tracings with an atrial tachyarrhythmia ≥30 s. Continuous measures across multiple time points were analysed using paired t-tests, and associations between various continuous measures were analysed using independent sample t-tests. Each statistical test used two-sided p values with a significance level of 0.05.ResultsBoth QOL instruments showed significant 12-month improvements across all domains: AFEQT score increased 25.1–37.5 points and 33.3%–50.8% fewer patients reporting any problem across EuroQoL EQ-5D-5L domains. Overall, AFEQT improvement was highly associated with AF burden (p=0.009 for 2DS2-VASc scores at baseline, and higher AF burden following PVI.ConclusionsQOL improved and healthcare utilisation decreased significantly after ablation with a standardised CLOSE protocol. QOL improvement was significantly associated with impairment at baseline and AF burden after ablation.Trial registration numberNCT03062046.

Aims The relation between atrial tachyarrhythmia (ATA) burden in paroxysmal atrial fibrillation (AF), atrial remodelling, and efficacy of catheter ablation (CA) is unknown. We investigated whether high vs. low-burden paroxysmal AF patients have distinct clinical characteristics or electro-mechanical properties of the left atrium (LA) and whether burden impacts outcome of CA. Methods and results Atrial tachyarrhythmia burden, defined as the percentage of time spent in ATA, was assessed by insertable cardiac monitors in 105 patients before and after CA. Clinical characteristics and electro-mechanical properties of LA were compared between patients with high vs. low ATA burden. Catheter ablation efficacy was assessed by reduction in ATA burden and 1-year freedom from any ATA. Median ATA burden was 2.7% (highest tertile 9.3%). Clinical characteristics and electrical properties of LA (refractoriness, conduction velocity, low voltage) did not differ between high (≥9.3%) vs. low ATA burden ( Conclusion Paroxysmal AF patients with high ATA burden have altered LA mechanical properties, reflected by larger size and impaired function. Despite mechanical remodelling of the atria, they are excellent responders to CA. Most likely the lack of fibrosis and/or advanced electrical remodelling explain why pulmonary veins remain the dominant trigger for AF in this patient cohort.

BACKGROUND Direct-acting oral anticoagulant use for stroke prevention in atrial fibrillation is limited by bleeding concerns. Asundexian, a novel, oral small molecule activated coagulation factor XIa (FXIa) inhibitor, might reduce thrombosis with minimal effect on haemostasis. We aimed to determine the optimal dose of asundexian and to compare the incidence of bleeding with that of apixaban in patients with atrial fibrillation. METHODS In this randomised, double-blind, phase 2 dose-finding study, we compared asundexian 20 mg or 50 mg once daily with apixaban 5 mg twice daily in patients aged 45 years or older with atrial fibrillation, a CHA2DS2-VASc score of at least 2 if male or at least 3 if female, and increased bleeding risk. The study was conducted at 93 sites in 14 countries, including 12 European countries, Canada, and Japan. Participants were randomly assigned (1:1:1) to a treatment group using an interactive web response system, with randomisation stratified by whether patients were receiving a direct-acting oral anticoagulant before the study start. Masking was achieved using a double-dummy design, with participants receiving both the assigned treatment and a placebo that resembled the non-assigned treatment. The primary endpoint was the composite of major or clinically relevant non-major bleeding according to International Society on Thrombosis and Haemostasis criteria, assessed in all patients who took at least one dose of study medication. This trial is registered with ClinicalTrials.gov, NCT04218266, and EudraCT, 2019-002365-35. FINDINGS Between Jan 30, 2020, and June 21, 2021, 862 patients were enrolled. 755 patients were randomly assigned to treatment. Two patients (assigned to asundexian 20 mg) never took any study medication, resulting in 753 patients being included in the analysis (249 received asundexian 20 mg, 254 received asundexian 50 g, and 250 received apixaban). The mean age of participants was 73·7 years (SD 8·3), 309 (41%) were women, 216 (29%) had chronic kidney disease, and mean CHA2DS2-VASc score was 3·9 (1·3). Asundexian 20 mg resulted in 81% inhibition of FXIa activity at trough concentrations and 90% inhibition at peak concentrations; asundexian 50 mg resulted in 92% inhibition at trough concentrations and 94% inhibition at peak concentrations. Ratios of incidence proportions for the primary endpoint were 0·50 (90% CI 0·14-1·68) for asundexian 20 mg (three events), 0·16 (0·01-0·99) for asundexian 50 mg (one event), and 0·33 (0·09-0·97) for pooled asundexian (four events) versus apixaban (six events). The rate of any adverse event occurring was similar in the three treatment groups: 118 (47%) with asundexian 20 mg, 120 (47%) with asundexian 50 mg, and 122 (49%) with apixaban. INTERPRETATION The FXIa inhibitor asundexian at doses of 20 mg and 50 mg once daily resulted in lower rates of bleeding compared with standard dosing of apixaban, with near-complete in-vivo FXIa inhibition, in patients with atrial fibrillation. FUNDING Bayer.

BACKGROUND There were gaps between guidelines and practice when surgery was the only treatment for aortic stenosis (AS). OBJECTIVES This study analyzed the decision to intervene in patients with severe AS in the EORP VHD (EURObservational Research Programme Valvular Heart Disease) II survey. METHODS Among 2,152 patients with severe AS, 1,271 patients with high-gradient AS who were symptomatic fulfilled a Class I recommendation for intervention according to the 2012 European Society of Cardiology guidelines; the primary end point was the decision for intervention. RESULTS A decision not to intervene was taken in 262 patients (20.6%). In multivariate analysis, the decision not to intervene was associated with older age (odds ratio [OR]: 1.34 per 10-year increase; 95% CI: 1.11 to 1.61; P = 0.002), New York Heart Association functional classes I and II versus III (OR: 1.63; 95% CI: 1.16 to 2.30; P = 0.005), higher age adjusted Charlson comorbidity index (OR: 1.09 per 1-point increase; 95% CI: 1.01 to 1.17; P = 0.03), and a lower transaortic mean gradient (OR: 0.81 per 10-mm Hg decrease; 95% CI: 0.71 to 0.92; P < 0.001). During the study period, 346 patients (40.2%, median age 84 years, median EuroSCORE II [European System for Cardiac Operative Risk Evaluation II] 3.1%) underwent transcatheter intervention and 515 (59.8%, median age 69 years, median EuroSCORE II 1.5%) underwent surgery. A decision not to intervene versus intervention was associated with lower 6-month survival (87.4%; 95% CI: 82.0 to 91.3 vs 94.6%; 95% CI: 92.8 to 95.9; P < 0.001). CONCLUSIONS A decision not to intervene was taken in 1 in 5 patients with severe symptomatic AS despite a Class I recommendation for intervention and the decision was particularly associated with older age and combined comorbidities. Transcatheter intervention was extensively used in octogenarians. (J Am Coll Cardiol 2021;78:2131-2143) (c) 2021 by the American College of Cardiology Foundation.

Case description : A 74-year-old man suffering from severe heart failure (NYHA III – LVEF 28%) associated with left bundle branch block (LBBB) (Figure 1(A)) and uncontrolled permanent atrial fibrillation (AF) despite optimal medical treatment was referred for His ablation and rescue physiological pacing after a first unsuccessful LV lead implantation through the coronary sinus (CS). Careful review of the occluded CS angiogram indeed revealed no side branches. Concordantly, the patient was offered a ‘rescue’ HBP procedure. Using the SelectSecure lead (model 3830) and a C315 His sheath (Both Medtronic, Inc. MN), His mapping (HV ¼ 106ms) and recruitment were easily obtained, unfortunately without LBBB correction.

Objectives: This study sought to evaluate the safety and short-term performance of a novel catheter for very high power–short duration (vHPSD) ablation in the treatment of paroxysmal atrial...

Aims We sought to evaluate the efficacy and the safety of a simple technique for stabilizing the ablation catheter during anterior pulmonary vein (PV) encirclement in patients ablated for paroxysmal atrial fibrillation. This consisted of bending the ablation catheter in the left atrium, creating a loop that was cautiously advanced together with the long sheath at the ostium and then within the left superior PV. The curve was then progressively released to reach a stable contact with the anterior part of the left PVs. Methods and results Eighty consecutive patients (age 64 ± 11 years, left atrial diameter 43 ± 8 mm) undergoing ‘CLOSE’-guided PV isolation were prospectively randomized into two groups depending on whether the loop technique was used or not. When using the loop technique, the encirclement of the left PVs was shorter [20 min (interquartile range, IQR 17–24) vs. 26 min (IQR 18–33), P Conclusion This study describes a simple technique to facilitate catheter stability at the anterior part of the left PVs, resulting in more efficient left PV encirclement without compromising safety.

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and represents a heterogeneous disorder with a complex pathological basis. While significant technological advances have taken place over the last decade in the field of catheter ablation of AF, response to ablation varies and long-term success rates in those with persistent AF remain modest. Mechanistic studies have highlighted potentially different sustaining factors for AF in the persistent AF population with substrate-driven focal and re-entrant sources in the body of the atria identified on invasive and non-invasive mapping studies. Translation to clinical practice, however, remains challenging and the application of such mapping techniques to clinical ablation has yet to demonstrate a significant benefit beyond pulmonary vein isolation (PVI) alone in the persistent AF cohort. Recent advances in catheter and ablation technology have centered on improving the durability of ablation lesions at index procedure and although encouraging results have been demonstrated with early studies, large-scale trials are awaited. Further meaningful improvement in clinical outcomes in the persistent AF population requires ongoing advancement in the understanding of AF mechanisms, coupled with continuing progress in catheter technology capable of delivering durable transmural lesions.

Introduction. During left bundle branch area pacing (LBBAP) lead implantation, intermittent monitoring of unipolar pacing characteristics validates LBB capture and can detect septal perforation. We aimed to demonstrate that continuous uninterrupted unipolar pacing from an inserted lead stylet (LS) is feasible and facilitates LBBAP implantation. Methods. Thirty patients (mean age 76 ± 14 years) were implanted with stylet-driven pacing lead (Biotronik Solia S60). In 10 patients (validation-group) conventional, interrupted implantation was performed, with comparison of unipolar pacing characteristics between LS and connector-pin (CP)-pacing after each rotation step. In 20 patients (feasibility-group) performance and safety of uninterrupted implantation during continuous pacing from the LS were analyzed. Results. In the validation-group, LS and CP-pacing impedances were highly correlated (R=0.95, p

IMPORTANCE: Mitral annular disjunction (MAD) has received particular interest in patients with mitral valve prolapse, ventricular tachycardia, and sudden cardiac death. The clinical significance of MAD for patients with Marfan syndrome (MFS) remains largely unexplored. OBJECTIVE: To define the prevalence of MAD and examine its association with cardiovascular outcomes and arrhythmia among patients with MFS. DESIGN, SETTING, AND PARTICIPANTS: This retrospective, single-center cohort study included 142 patients with a diagnosis of MFS based on the revised Ghent criteria and a confirmed (likely) pathogenic variant in the FBN1 gene who underwent regular follow-up between January 1, 2004, and December 31, 2019. MAIN OUTCOMES AND MEASURES: The presence of MAD was assessed by echocardiography, and the extent of MAD was categorized in tertiles. Patients also underwent resting electrocardiography and 24-hour Holter monitoring. Outcomes included aortic events (aortic dissection or prophylactic aortic surgery), arrhythmic events (defined as sustained ventricular tachycardia or sudden cardiac death), and mitral valve surgery. RESULTS: A total of 142 patients (72 female patients [51%]; median age at first examination, 25 years [range, 2-64 years]) were evaluated. Forty-eight patients (34%) had MAD. Patients with MAD had larger aortic root z scores than patients without MAD (4.1 [interquartile range, 2.8-5.7] vs 3.0 [interquartile range, 1.8-4.0]; P 10 mm) showed a higher occurrence of aortic events compared with patients with MAD of 10 mm or smaller (9 of 15 [60%] vs 6 of 28 [21%]; P = .01). Patients with arrhythmic events (n = 5) and patients requiring mitral valve surgery (n = 7) were observed exclusively in the group displaying MAD. CONCLUSIONS AND RELEVANCE: This study suggests that MAD among patients with MFS is associated with the occurrence of arrhythmic events, a higher need for mitral valve intervention, and, among patients with extensive MAD, more aortic events. Cardiac imaging for patients with MFS should consider the assessment of MAD as a potential marker for adverse outcomes.

The QDOT Micro™ catheter (Biosense Webster, Inc., CA, USA) is a new radiofrequency ablation catheter based on the SmartTouch SF™ (Biosense Webster, Inc.). It combines diffuse external irrigation with six thermocouples located within the outer metal shell and three additional microelectrodes in a 3.5 mm-tip contact force radiofrequency catheter. This article focuses on the different characteristics of the catheter, which incorporates the ability of high power delivery, irrigation flow control based on temperature sensing through the six thermocouples and the generation of microelectrograms. An outline of its performance in preclinical and clinical setting is presented, showing promising results, especially concerning procedural efficiency and short-term safety. Additional studies need to confirm long-term effectiveness, and durability studies should evaluate whether superiority on a lesion quality level can be achieved.Lay abstract Radiofrequency (RF) energy is the most widely used type of energy in the field of catheter ablation, an invasive treatment for heart rhythm disorders. In patients with atrial fibrillation (AF; the most frequent type of problem with the rhythm of the heart), catheter ablation aims at delivering RF energy around the pulmonary veins (PVs). PVs have been shown to contain AF triggers. Catheter ablation results in electrical isolation of the PV, making them less likely to trigger AF. The latest technical developments resulted in better success rate of the procedure (up to 90% success rate after 1 year follow-up) without increasing complication rates. During the last decade, the catheter used to isolate the PV has improved a lot and includes now contact force measurement in addition to the delivery mechanism for RF energy and can record the local electrical activity. The newly developed QDOT Micro™ catheter (Biosense Webster, Inc., CA, USA), presented in this article, combines different aspects of further technical development. These include the integration of smaller electrodes, resulting in higher local electrical signal resolution, more accurate feedback of local tissue temperature during the procedure and the ability to use higher RF power which reduces the RF delivery time and therefore reduced the duration of the procedure. An outline of its performance in preclinical and clinical setting is presented in this paper. These studies have shown promising results, especially concerning procedural efficiency and short-term safety. However, additional studies need to confirm long-term treatment success and potential superiority in comparison with other ablation approaches.

Funding Acknowledgements Type of funding sources: None. Background Entrainment mapping (EM) is an important tool to determine the mechanism of complex reentrant atrial tachycardias (ATs), mostly to distinguish dominant from bystander reentrant loops. However, entrainment maneuvers are challenging, time consuming and risk to end the tachycardia. Purpose Recently, we developed a novel method Directed Graph Mapping (DGM), using concepts of network theory, allowing to automatically determine AT reentry loops from the local activation times (LAT) of any clinical mapping system. DGM showed good performance: it correctly finds ablation target (100 % success rate) on simple AT cases and could automatically determine reentry loops confirmed by the expert electrophysiologist with EM in complex AT cases. Out of 32 single loop cases, 62.5 % was identified correctly with automated DGM and out of 6 true double loop cases, 83.3 %. Lower performance for single reentry complex cases compared to EM was mainly because DGM could not distinguish the dominant loop from additional bystander loops found by DGM. Hence, the purpose of this work was to develop additional algorithms which in case of multiple found DGM loops could automatically find the dominant loop and compare it with the results of EM. Methods We performed multiple simulations of various types of double loop reentry on a patient specific model of the left atrium. Based on a clinical case, double loops were simulated around a scar at the anterior wall (localized reentry) and the mitral valve (MV). LAT maps were determined similar as in the clinic. By varying the size of the scar in multiple steps, we obtained a transition from a regime of a dominant loop around the scar (small scar), to a true double loop and further to a regime of a dominant loop around the MV (large scar). We developed a novel DGM algorithm to determine the dominant loop from the region of collision (ROC) found from the vector field of the wavefront graph. The developed method was also tested on 8 clinical cases of double loop ATs with EM measurements. Results Our algorithm found the location of the ROC and determined the correct dominant loop in 100% of the simulated data. We tested this on 8 clinical cases of AT, and accuracy of the method was 75 %. Conclusions Determining the ROC in case of multiple loops in AT could correctly determine the dominant versus bystander loop, leading to the correct ablation target, without the need for further EM.

Conventional stylet-driven leads with extendable helix can be implanted successfully for Left Bundle Branch Area Pacing (LBBAP) with a low acute complication rate. However, removal and repositioning techniques of these leads haven’t been yet described. We report 2 cases in which lead repositioning after a first unsuccessful attempt to LBBAP was associated with fracture of the helix rotating mechanism and failure to fully extract the pacing lead.

Life threatening cardiac arrhythmias result from abnormal propagation of nonlinear electrical excitation waves in the heart. Finding the locations of the sources of these waves remains a challenging problem. This is mainly due to the low spatial resolution of electrode recordings of these waves. Also, these recordings are subjected to noise. In this paper, we develop a different approach: the AFV-DT method based on an averaged flow velocity (AFV) technique adopted from the analysis of optical flows and the determinant-trace (DT) method used for vector field analysis of dynamical systems. This method can find the location and determine all important types of sources found in excitable media such as focal activity, spiral waves, and waves rotating around obstacles. We test this method on in silico data of various wave excitation patterns obtained using the Luo-Rudy model for cardiac tissue. We show that the method works well for data with low spatial resolutions (up to 8×8) and is stable against noise. Finally, we apply it to two clinical cases and show that it can correctly identify the arrhythmia type and location. We discuss further steps on the development and improvement of this approach. © 2021 American Physical Society. This work was supported by the National Natural Science Foundation of China under Grants No. 12075203 and No. 11975194, and research at Sechenov University was financed by the Ministry of Science and Higher Education of the Russian Federation within the framework of state support for the creation and development of World-Class Research Centers “Digital biodesign and personalized healthcare” (Grant No. 075-15-2020-926).

Objectives: Directed graph-mapping (DGM) is a novel operator-independent automatic tool that can be applied to the identification of the atrial tachycardia (AT) mechanism. In the present study, for the first time, DGM was applied in complex AT cases, and diagnostic accuracy was evaluated. Background: Catheter ablation of ATs still represents a challenge, as the identification of the correct mechanism can be difficult. New algorithms for high-density activation mapping (HDAM) render an easier acquisition of more detailed maps; however, understanding of the mechanism and, thus, identification of the ablation targets, especially in complex cases, remains strongly operator-dependent. Methods: HDAMs acquired with the latest algorithm (COHERENT version 7, Biosense Webster, Irvine, California) were interpreted offline by 4 expert electrophysiologists, and the acquired electrode recordings with corresponding local activation times (LATs) were analyzed by DGM (also offline). Entrainment maneuvers (EM) were performed to understand the correct mechanism, which was then confirmed by successful ablation (13 cases were centrifugal, 10 cases were localized re-entry, 22 cases were macro–re-entry, and 6 were double-loops). In total, 51 ATs were retrospectively analyzed. We compared the diagnoses made by DGM were compared with those of the experts and with additional EM results. Results: In total, 51 ATs were retrospectively analyzed. Experts diagnosed the correct AT mechanism and location in 33 cases versus DGM in 38 cases. Diagnostic accuracy varied according to different AT mechanisms. The 13 centrifugal activation patterns were always correctly identified by both methods; 2 of 10 localized reentries were identified by the experts, whereas DGM diagnosed 7 of 10. For the macro–re-entries, 12 of 22 were correctly identified using HDAM versus 13 of 22 for DGM. Finally, 6 of 6 double-loops were correctly identified by the experts, versus 5 of 6 for DGM. Conclusions: Even in complex cases, DGM provides an automatic, fast, and operator-independent tool to identify the AT mechanism and location and could be a valuable addition to current mapping technologies. © 2021 The Authors. Dr. Lorenzo is an employee of Biosense Webster. Dr. Goedgebeur is funded with a research grant of the Research Foundation Flanders/Fonds voor Wetenschappelijk Onderzoek (FWO). Dr. Strisciuglio is supported by a research grant from the Cardiopath PhD program. Dr. el Haddad is a consultant for Biosense Webster. Dr. Duytschaever is a consultant for Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Background: CLOSE-guided atrial fibrillation (AF) ablation is based on contiguous (intertag distance ≤6 mm), optimized (Ablation Index >550 anteriorly and >400 posteriorly) point-by-point radiofrequency lesions. The optimal radiofrequency power remains unknown. Methods: The POWER-AF study is a prospective, randomized controlled monocentric study including patients with paroxysmal AF, planned for first CLOSE-guided pulmonary vein isolation using a contact force radiofrequency catheter (Thermocool SmartTouch, Biosense Webster, Inc, Irvine, CA). A total of 100 patients were randomized into 2 groups (1:1). The control group received AF ablation using the standard CLOSE protocol (35 W), whereas in the experimental group, pulmonary vein isolation was performed using high power (45 W). Endoscopic evaluation was performed in patients with intraesophageal temperature rise >38.5 °C. Results: The resulting sample size was 96 (48+48) patients. In the high power group, shorter procedure time (80 versus 102 minutes, P P P P P =0.31) showed an ulcerative perforation in a high power group patient (treated by endoscopic stenting and normalization after ≈4 months) and a superficial ulcerative lesion in a control group patient (conservative treatment). Both occurred following excessive Ablation Index applications (up to 460 and 480, respectively) with excessive contact force (30 g on average, with peaks up to 50 g). Six-months AF recurrence was not significantly different (10% in high power versus 8% in control, P =0.74). Conclusions: This randomized controlled study shows that a 45 W radiofrequency power CLOSE protocol in patients with paroxysmal AF significantly increases the global procedural efficiency with similar midterm efficacy. However, our study showed a narrower safety margin and a limited increased efficiency at the posterior wall using high power. This advocates against the use of high power in the region neighboring the esophagus.

Aims To evaluate the safety and effectiveness of pulmonary vein isolation in paroxysmal atrial fibrillation (PAF) using a standardized workflow aiming to enclose the veins with contiguous and optimized radiofrequency lesions. Methods and results This multicentre, prospective, non-randomized study was conducted at 17 European sites. Pulmonary vein isolation was guided by VISITAG SURPOINT (VS target ≥550 on the anterior wall; ≥400 on the posterior wall) and intertag distance (≤6 mm). Atrial arrhythmia recurrence was stringently monitored with weekly and symptom-driven transtelephonic monitoring on top of standard-of-care monitoring (24-h Holter and 12-lead electrocardiogram at 3, 6, and 12 months follow-up). Three hundred and forty participants with drug refractory PAF were enrolled. Acute effectiveness (first-pass isolation proof to a 30-min wait period and adenosine challenge) was 82.4% [95% confidence interval (CI) 77.4–86.7%]. At 12-month follow-up, the rate of freedom from any documented atrial arrhythmia was 78.3% (95% CI 73.8–82.8%), while freedom from atrial arrhythmia by standard-of-care monitoring was 89.4% (95% CI 78.8–87.0%). Freedom fromrepeat ablations by the Kaplan–Meier analysis was 90.4% during 12 months of follow-up. Of the 34 patients with repeat ablations, 14 (41.2%) demonstrated full isolation of all pulmonary vein circles. Primary adverse event (PAE) rate was 3.6% (95% CI 1.9–6.3%). Conclusions The VISTAX trial demonstrated that a standardized PAF ablation workflow aiming for contiguous lesions leads to low rates of PAEs, high acute first-pass isolation rates, and 12-month freedom from arrhythmias approaching 80%. Further research is needed to improve the reproducibility of the outcomes across a wider range of centres. Clinical trial registration: ClinicalTrials.gov, number NCT03062046, https://clinicaltrials.gov/ct2/show/NCT03062046.

Aims Catheter ablation of paroxysmal atrial fibrillation (AF) reduces AF recurrence, AF burden, and improves quality of life. Data on clinical and procedural predictors of arrhythmia recurrence are scarce and are flawed by the high rate of pulmonary vein reconnection evidenced during repeat procedures after pulmonary vein isolation (PVI). In this study, we identified clinical and procedural predictors for AF recurrence 1 year after CLOSE-guided PVI, as this strategy has been associated with an increased PVI durability. Methods and results Patients with paroxysmal AF, who received CLOSE-guided PVI and who participated in a prospective trial in our centre, were included in this study. Uni- and multivariate models were plotted to find clinical and procedural predictors for AF recurrence within 1 year. Three hundred twenty-five patients with a mean age of 63 years (CHA2DS2VASc 1 [1–3], left atrium diameter 41 ± 6 mm) were included. About 60.9% were male individuals. After 1 year, AF recurrence occurred in 10.5% of patients. In a binary logistic regression analysis, the diagnosis-to-ablation time (DAT) was found to be the strongest predictor of AF recurrence (P = 0.011). Diagnosis-to-ablation time ≥1 year was associated with a nearly two-fold increased risk for developing AF recurrence. Conclusion The DAT is the most important predictor of arrhythmia recurrence in low-risk patients treated with durable pulmonary vein isolation for paroxysmal AF. Whether reducing the DAT could improve long-term outcomes should be investigated in another trial.

Background Recurrent arrhythmia following catheter ablation of atrial fibrillation (AF) may present early, during a standard 3-month blanking period. Early recurrence has been correlated to late recurrence, but the degree to which its absence predicts longer-term success has not been quantified. Objective The purpose of this study was to explore and quantify the relationship between early and late arrhythmia recurrence, specifically the negative predictive value, that is, the degree to which absence of blanking period recurrence predicts absence of late recurrence. Methods A systematic literature review and meta-analysis were conducted using statistical methods of a diagnostic test accuracy review. Studies of AF ablation using point-by-point radiofrequency, with repeated monitoring of arrhythmia recurrence including asymptomatic recurrence, and with separate data by AF type, were eligible. Results Nine studies met the prespecified eligibility criteria. For paroxysmal AF, 89% (confidence interval [CI] 82%–94%) of patients free from early recurrence remained free from late recurrence. The estimate for persistent AF was similar (91%; CI 75%–97%). This finding was robust in sensitivity analyses. Patients with early recurrence had a wider range of likely outcomes with longer-term follow-up. Conclusion Freedom from AF recurrence during the blanking period is highly predictive of longer-term success in catheter ablation. Clinical trials in this area may be able to leverage these findings to more quickly assess the potential utility of new ablation technologies and methods, for example, by using early surrogate measures of success.

Aims: “CLOSE”-guided pulmonary vein isolation (PVI) is based on contiguous (≤6 mm) and optimized radiofrequency (RF) ablation lesions (ablation index [AI] ≥ 400 posteriorly and ≥ 550 anteriorly]. However, the optimal RF power to reach the desired AI is unknown. Therefore we evaluated the efficiency of an ablation strategy using higher power (40 W) during a first “CLOSE”-guided PVI. Methods: Eighty consecutive patients undergoing “CLOSE”-guided PVI for symptomatic paroxysmal atrial fibrillation were ablated with 40 W (group A). Results were compared with 105 consecutive patients enrolled in the “CLOSE to CURE”-study and were ablated using the same protocol with 35 W (group B). Results: In group A, ablation was associated with shorter ablation procedure time (91 vs 111 minutes; P .733) were similar in both groups (groups A and B, respectively). No complications occurred. In group A, a gastroscopy—performed in five patients with esophageal temperature rise more than 42°C—did not reveal any esophageal lesion. Postprocedural recurrence of atrial tachyarrhythmia at 1 year was not significantly different between both groups. Conclusions: Using the “CLOSE”-protocol, increased power increases the efficiency of PVI without compromising patients' safety., SCOPUS: ar.j, info:eu-repo/semantics/published

Biventricular pacing (BVP) has been demonstrated to improve functional outcomes and mortality of patients with symptomatic heart failure, reduced LVEF and wide QRS. Unfortunately, difficult coronary sinus anatomy can limit left ventricular lead placement. In such clinical situation, His Bundle Pacing (HBP) and Left Bundle Branch Area Pacing (LBBAP) have recently appeared as attractive alternatives to BVP. We describe the case of a patient with an indication for Cardiac Resynchronization Therapy (CRT) and AV node ablation, where left ventricular lead implantation and corrective HBP failed. LBBAP allowed for electrical and echocardiographic resynchronization with significant functional improvement.

In this study the authors hypothesized that "Lean management" within a dedicated ablation protocol could standardize the pulmonary vein isolation (PVI) procedure and improve quality.There is a large variability in safety, effectiveness, and efficiency of PVI.This was a single-center prospective study with inclusion of all consecutive PVI procedures from 2017 to 2019. A 3-step intervention was introduced based on Lean management: step 1) simplification (CLOSE protocol); step 2) waste elimination (higher power shorter duration); and step 3) improved standardization (Lab Optimization Tool [LOT]). PVI was divided into steps that were tracked (in minutes) using LOT. Parameters were compared in 6-month intervals.Overall, 295 patients (146 patients with LOT) were analyzed. Step 1 reduced skin-to-skin procedure duration (2017: 119 ± 21 min vs. 2018: 77 ± 15 min; p 0.001) and variance (from 2018 to 2019 p = 0.024). Step 2 reduced the radiofrequency time (2017: 38 ± 6 min vs. 2018: 20 ± 3 min; p 0.001) and variance (from 2018 to 2019 p 0.001). Analysis of step 3 demonstrated that only 53% of the entire procedure length (143 ± 22 min) was used for treatment (skin-to-skin time 77 ± 16 min), the remaining time being devoted for setup (42 ± 12 min, 29%); left atrial access (16 ± 7 min, 12%); respiratory gating, left atrial map, and pseudo-circle annotation (10 ± 6 min, 7%); ablation (39 ± 10 min, 27%); and bilateral block validation (10 ± 8 min, 7%).Standardization of PVI using a dedicated ablation protocol and Lean management can help to reduce procedure and radiofrequency ablation duration and variance, and increase procedural efficiency without compromising safety. To improve health care utilization, increased efficiency should become an accepted goal in addition to procedural safety and effectiveness.

Objectives This study sought to evaluate the safety and the acute and 1 year outcomes of an ablation protocol aiming to enclose the PV with a contiguous and optimized RF circle by targeting region-specific criteria for lesion depth assessed by ablation index and interlesion distance. Background Reconnections after pulmonary vein (PV) isolation are explained by insufficient lesion depth and/or discontiguity of radiofrequency (RF) lesions. Methods A total of 130 consecutive patients with paroxysmal atrial fibrillation (AF) underwent PV encircling using a contact force–sensing catheter. RF was delivered targeting interlesion distance ≤6 mm and ablation index ≥400 at posterior wall and ≥550 at anterior wall. Recurrence was defined as any AF, atrial tachycardia (AT), or atrial flutter (AFL) (AF/AT/AFL >30 s) on Holter electrocardiographs at 3, 6, and 12 months. Results Procedure and RF time per circle were 155 ± 28 min and 17 ± 5 min, respectively. Incidence of first-pass and adenosine-proof isolation were 98% and 98%, respectively. One short-lived transient ischemic attack was observed. At 12 months, single-procedure freedom from AF/AT/AFL was 91.3% in those 104 patients off antiarrhythmic drug therapy and 96.2% in those 26 patients on antiarrhythmic drug therapy. Single-procedure freedom from both AF/AT/AFL and antiarrhythmic drug therapy was 73.1%. Conclusions This study suggests that an ablation protocol respecting strict criteria for lesion depth and contiguity results in acute durable PV isolation followed by a high single-procedure arrhythmia-free survival at 1 year. A prospective, multicenter trial is ongoing.

Background: Few studies evaluated the impact of catheter ablation (CA) on atrial tachyarrhythmia (ATA) burden in paroxysmal atrial fibrillation (AF). Objective: In the prospective, patient-controlled CLOSE to CURE study, we determined the longer-term impact of optimized CA on ATA burden by using an insertable cardiac monitor (ICM). Methods: A total of 105 patients with paroxysmal AF were implanted with an ICM 65 (interquartile range [IQR] 61–78) days before CA. CA consisted of contact force–guided pulmonary vein isolation targeting an intertag distance of ≤6 mm and a region-specific ablation index. The primary end point was reduction in ICM-detected ATA burden; secondary end points were single-procedure freedom from ATA, quality of life, and adverse events. Results: The mean age was 62 ± 8 years; the median CHA2DS2-VASc score was 1 (IQR 1–2); and the median left atrial diameter was 43 (IQR 39–43) mm. After pulmonary vein isolation (1.13 ± 0.39 procedures per patient), median ATA burden decreased from 2.68% (IQR 0.09%–15.02%) at baseline to 0% (IQR 0%–0%) during the first year and to 0% (IQR 0%–0%) during the second year (reduction in ATA burden 100% [IQR 100%–100%]; P < .001). Single-procedure freedom from any ATA was 87% at 1 year and 78% at 2 years. Quality of life improved significantly across all scores. Adverse events occurred in 5 patients (4.8%). Conclusion: CA has become an effective procedure in paroxysmal AF, with a major impact on ICM-detected ATA burden. Whereas conventional survival analysis suggests a progressive decline in efficacy, we observed that burden reduction is maintained at longer follow-up. These data imply that ATA burden is a more optimal end point for assessing ablation efficacy.

Catheter ablation for atrial fibrillation (AF) is a common treatment strategy in patients with drug-resistant, symptomatic AF. In patients with paroxysmal and short-standing persistent AF, pulmonary vein isolation (PVI) is often enough to prevent recurrence of atrial tachyarrhythmia (ATA). Point-by-point encircling of the PVs with radiofrequency (RF) applications, together with cryoballoon ablation, have been the mainstay strategies for the last 10 to 20 years. Each of these strategies, however, suffers from the delicate balance between preventing PV reconnection, on the one hand (toward more energy), and preventing (mainly esophageal) complications (toward less energy), on the other. The CLOSE protocol was developed as an RF ablation strategy that would result in the safe creation of durable isolation leading to improved outcomes. Basically, the aim of the protocol is to enclose the pulmonary veins with stable, contiguous (intertag distance, ITD ≤ 6 mm) and optimized lesions (35 Watts, W, RF applications up to ablation index targets of ≥400 and ≥550 at the posterior and anterior wall). In this review, we describe the background of the CLOSE protocol and the studies from the St Jan Bruges research group on procedural performance, efficacy, and safety of the CLOSE protocol in (a) single-center prospective PILOT study (CLOSE-PILOT), (b) a single-center prospective study with continuous rhythm monitoring (CLOSE to CURE), (c) a database of systematic esophageal endoscopic studies, (d) a multicenter prospective study (VISTAX), and (e) the CLOSE database (comprising > 400 patients). We also discuss the results of the randomized POWER-AF study comparing conventional CLOSE to high power CLOSE (up to 50 W). Finally, we discuss the performance, safety, and efficacy of the CLOSE protocol in light of the emerging changes in the field of catheter ablation being ultra-short high-power ablation and electroporation.

Aims Non-invasive electrocardiogram (ECG) mapping allows the activation of the entire atrial epicardium to be recorded simultaneously, potentially identifying mechanisms critical for atrial fibrillation (AF) persistence. We sought to evaluate the utility of ECG mapping as a practical tool prior to ablation of persistent AF (PsAF) in centres with no practical experience of the system. Methods and results A total of 118 patients with continuous AF duration