Pulsed-field ablation: a breakthrough treatment for atrial fibrillation.

T De Potter leads the electrophysiology unit of the Cardiovascular Center in Aalst, Belgium, where he has practiced cardiology since 2009. He is actively involved in early-stage clinical research in the field of ablation and has performed the world's first ablation using the J&J pulsed-field ablation platform.

Utilization of 3D mapping systems in interventional electrophysiology and its impact on procedure time and fluoroscopy-Insights from the "Go for Zero Fluoroscopy" project.

AIM: The implementation of 3D mapping systems plays an important role in interventional electrophysiology (EP) in recent years. The aim of the present study was to evaluate use of 3D mapping systems regarding fluoroscopy and procedure duration. METHOD: In the "Go for Zero Fluoroscopy" project 25 European centers provided data of consecutive EP procedures. Data on use of 3D mapping systems as well as utilization of contact force catheters and multipolar mapping catheters were associated with fluoroscopy time, dose area product (DAP), and procedure duration. RESULT: A 3D mapping system was used in 966 (54%) cases. Use of 3D mapping for atrioventricular nodal reentry tachycardia (AVNRT) was associated with reduced fluoroscopy time (p < 0.001), DAP (p = 0.04) but increased procedure time (p = 0.029). Moreover, fluoroscopy time (p < 0.001) and DAP (p = 0.005) were significantly lower in the 3D mapping group in ablation of typical atrial flutter. However, the procedure time (p < 0.001) increased. Use of 3D mapping in the ablation of accessory pathway (AP) was associated with reduced fluoroscopy time (p < 0.001) and DAP (p < 0.001) with no significant increase in procedure time (p = 0.066). In the case of atrial fibrillation, a 3D mapping system was used in 485 patients (75.8%). Additional use of a contact force catheter was associated with lower fluoroscopy time (p < 0.001) and DAP (p < 0.001). Use of a multipolar mapping catheter was associated with lower fluoroscopy time (p = 0.002). The implementation of 3D mapping systems in the ablation of ventricular tachycardias resulted in a significant increase in the procedure time (p = 0.001) without significant differences regarding the DAP (p = 0.773) and fluoroscopy time (p = 0.249). CONCLUSION: Use of 3D mapping systems in ablation of supraventricular tachycardias is associated with lower radiation exposure. Nevertheless, the procedure time often increases, except in the case of ablation for AP. Use of contact force catheters and multipolar mapping catheters is associated with yet lower radiation exposure values. Prospective randomized studies are needed to further elucidate potential benefit of these technological tools.

Critical appraisal of technologies to assess electrical activity during atrial fibrillation: a position paper from the European heart rhythm association and European society of cardiology working group on ecardiology in collaboration with the heart rhythm society, Asia pacific heart rhythm society, Latin American Heart rhythm society and computing in cardiology

Abstract We aim to provide a critical appraisal of basic concepts underlying signal recording and processing technologies applied for (I) atrial fibrillation (AF) mapping to unravel AF mechanisms and/or identifying target sites for AF therapy and (ii) AF detection, to optimize usage of technologies, stimulate research aimed at closing knowledge gaps, and developing ideal AF recording and processing technologies. Recording and processing techniques for assessment of electrical activity during AF essential for diagnosis and guiding ablative therapy including body surface electrocardiograms (ECG) and endo- or epicardial electrograms (EGM) are evaluated. Discussion of (I) differences in uni-, bi-, and multi-polar (omnipolar/Laplacian) recording modes, (ii) impact of recording technologies on EGM morphology, (iii) global or local mapping using various types of EGM involving signal processing techniques including isochronal-, voltage- fractionation-, dipole density-, and rotor mapping, enabling derivation of parameters like atrial rate, entropy, conduction velocity/direction, (iv) value of epicardial and optical mapping, (v) AF detection by cardiac implantable electronic devices containing various detection algorithms applicable to stored EGMs, (vi) contribution of machine learning (ML) to further improvement of signals processing technologies. Recording and processing of EGM (or ECG) are the cornerstones of (body surface) mapping of AF. Currently available AF recording and processing technologies are mainly restricted to specific applications or have technological limitations. Improvements in AF mapping by obtaining highest fidelity source signals (e. g. catheter­electrode combinations) for signal processing (e. g. filtering, digitization, and noise elimination) is of utmost importance. Novel acquisition instruments (multi-polar catheters combined with improved physical modelling and ML techniques) will enable enhanced and automated interpretation of EGM recordings in the near future.

Temperature-Controlled Catheter Ablation for Paroxysmal Atrial Fibrillation: the QDOT-MICRO Workflow Sttudy.

BACKGROUND: A novel QDOT MICRO (Biosense Webster, Inc., Irvine, CA) catheter with optimized temperature control and microelectrodes was designed to incorporate real-time temperature sensing with contact force detection and microelectrodes to streamline ablation workflow. The QDOT-MICRO feasibility study evaluated the workflow, performance, and safety of temperature-controlled catheter ablation in patients with symptomatic paroxysmal atrial fibrillation with conventional ablation setting. METHODS: This was a non-randomized, single-arm, first-in-human study. The primary outcome was pulmonary vein isolation (PVI), confirmed by entrance block after adenosine and/or isoproterenol challenge. Safety outcomes included incidences of early-onset primary adverse events (AEs) and serious adverse device effects (SADEs). Device performance was evaluated via physician survey. RESULTS: All evaluated patients (n = 42) displayed 100% PVI. Two primary AEs (4.8%) were reported: 1 pericarditis and 1 vascular pseudoaneurysm. An additional SADE of localized infection was reported in 1 patient. No stroke, patient deaths, or other unanticipated AEs were reported. Average power delivered was 32.1±4.1 W, with a mean temperature of 40.8°C±1.6°C. Mean procedure (including 20-minute wait), fluoroscopy, and radiofrequency application times were 129.8, 6.7, and 34.0 minutes, respectively. On device performance, physicians reported overall satisfactory performance with the new catheter, with highest scores for satisfaction and usefulness of the temperature indicator. CONCLUSIONS: Initial clinical experience with the novel catheter showed 100% acute PVI success and acceptable safety and device performance in temperature-controlled ablation mode. There were no deaths, stroke, or unanticipated AEs. Fluoroscopy and procedural times were short and similar or better than reported for prior generation catheters.

Quality of life and healthcare utilisation improvements after atrial fibrillation ablation.

OBJECTIVE: Pulmonary 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. METHODS: CLOSE-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. RESULTS: Both 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 <10% vs ≥10% burden, p<0.001 for <20% vs ≥20% burden). Cardiovascular hospitalisations were significantly decreased after ablation (42%, p=0.001). Patients without substantial improvement in AFEQT (55/301, 18.2%) had higher AFEQT and CHA2DS2-VASc scores at baseline, and higher AF burden following PVI. CONCLUSIONS: QOL 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 NUMBER: NCT03062046.

Comparative effectiveness of catheter ablation devices in the treatment of atrial fibrillation: a network meta-analysis.

Atrial fibrillation (AF) ablation is most commonly performed using radiofrequency (RF) and cryoballoon (CB) catheters. Ablation Index is a novel lesion-quality marker associated with improved outcomes in RF ablation. Due to lack of direct comparative evidence between the latest generations of technologies, there is uncertainty regarding the best treatment option. Aim: To conduct a network meta-analysis to evaluate the comparative effectiveness of RF with Ablation Index to other catheter ablation devices in the treatment of AF. Methods: Searches for randomized and nonrandomized prospective comparative studies of ablation catheters were conducted in multiple databases. The outcome of interest was 12-month freedom from atrial arrhythmias after a single ablation procedure. Studies were grouped as high-, low- and unclear-quality based on study design and balanced baseline patient characteristics. Bayesian hierarchical network meta-analysis was conducted and results presented as relative risk ratios with 95% credible intervals (CrIs). Results: 12 studies evaluating five different catheter ablation devices were included. Radiofrequency ablation with Ablation Index was associated with statistically significantly greater probability of 12-month freedom from atrial arrhythmias than Arctic Front (relative risk: 1.77; 95% CrI: 1.21-2.87), Arctic Front Advance™ (1.41; 1.06-2.47), THERMOCOOL™ (1.34; 1.17-1.48) and THERMOCOOL SMARTTOUCH™ (1.09; 1-1.3). Results were robust in multiple sensitivity analyses. Conclusion: Radiofrequency catheter with Ablation Index is superior to currently available options for 12-month freedom from atrial arrhythmias after AF ablation. This study provides decision-makers with robust, pooled, comparative evidence of the latest ablation technologies.

Cierre de orejuela izquierda en pacientes mayores de 85 años: seguridad y eficacia del registro EWOLUTION / Left atrial appendage occlusion in patients older than 85 years. Safety and efficacy in the EWOLUTION registry

INTRODUCCIÓN Y OBJETIVOS: Los pacientes ancianos con fibrilación auricular están en mayor riesgo de eventos cardioembólicos y hemorragia mayor que los más jóvenes. El cierre de la orejuela izquierda (COI) podría ser una opción atractiva para estos pacientes, pero hay pocos datos sobre los resultados del COI de pacientes de 85 o más años. El objetivo del presente estudio es evaluar la seguridad y la eficacia del COI de pacientes de 85 o más años. MÉTODOS: Se analizó a 1.025 pacientes incluidos en el registro EWOLUTION que se habían sometido al COI, se identificó a 84 de edad ≥ 85 años y se los comparó con el grupo de menos edad. RESULTADOS: Los pacientes de 85 o más años tenían mayores riesgos estimados de accidente cerebrovascular y de hemorragias que los pacientes más jóvenes (edad ≥ 85 frente a <85 años: CHA2DS2-VASc, 5,2+/-1,2 frente a 4,4+/-1,6; p <0,0001; HAS-BLED, 2,7+/-1,1 frente a 2,3+/-1,2; p = 0,003). Las tasas de éxito del procedimiento fueron altas y similares en ambos grupos (el 98,8 frente al 98,5%; p = 0,99). No hubo diferencias en las tasas de eventos adversos relacionados con el dispositivo o el procedimiento a los 7 días (el 2,6 frente al 3,1%; p = 0,80). A pesar del mayor riesgo basal de accidente cerebrovascular, en el seguimiento no hubo diferencias entre los grupos en la tasa de ictus anualizada (0,8 frente a 1,3/100 pacientes-año; p = 0,649). CONCLUSIONES: El COI de los pacientes de edad ≥ 85 años es seguro y eficaz a pesar del alto riesgo de eventos embólicos y hemorrágicos de estos pacientes. El COI puede ser una alternativa razonable a la anticoagulación oral para estos pacientes

INTRODUCTION AND OBJECTIVES: Elderly patients with atrial fibrillation are at greater risk of both cardioembolic events and major bleeding than younger patients. Left atrial appendage occlusion (LAAO) could be an attractive alternative for these patients, but there are limited data on outcomes with LAAO in patients ≥ 85 years old. The aim of the present study was to assess the safety and efficacy of LAAO in patients ≥ 85 years old. METHODS: A total of 1025 patients included in the EWOLUTION registry who underwent LAAO were analyzed and 84 patients ≥ 85 years old were identified and compared with the younger cohort. RESULTS: Patients ≥ 85 years old had higher estimated stroke and hemorrhagic risks than younger patients (CHA2DS2-VASc: 5.2+/-1.2 vs 4.4+/-1.6, P <.0001; HAS-BLED: 2.7+/-1.1 vs 2.3+/-1.2; P=.003; ≥ 85 years vs <85 years). Procedural success was high and similar in both groups (98.8% vs 98.5%; P=.99). There were no differences in 7-day device- or procedure-related adverse event rates (2.6% in ≥ 85 years vs 3.1% in <85 years; P=.80). Despite the higher baseline stroke risk, there was no difference at follow-up between the groups in the annualized stroke rate (0.8/100 patient-years in ≥ 85 years vs 1.3/100 patient-years in <85 years; P=.649). CONCLUSIONS: LAAO in patients ≥ 85 years is safe and effective even though these patients are at high risk for embolic and hemorrhagic events. LAAO may be a reasonable alternative to oral anticoagulation in these patients

Safety and Long-Term Success of Persistent Atrial Fibrillation Ablation Using THERMOCOOL SMARTTOUCH® Catheter: Real-World Experience.

BACKGROUND: To investigate the real-world clinical experience of persistent atrial fibrillation (persAF) ablation using the THERMOCOOL SMARTTOUCH® catheter with contact force (CF)-sensing ability in a prospective, multicenter registry. METHODS: Patients with persAF (excluding long-standing persAF) undergoing ablation were enrolled. Primary adverse events (AEs), 12-month success, quality of life (QoL), and correlation of success with CF were assessed. RESULTS: Overall, 150 patients with persAF (age 61.6 ± 9.4 years; 76.0% male; 90.7% Caucasian; left ventricular ejection fraction 56.9% ± 10.3%; left atrial diameter 41.5 ± 7.9 mm) underwent catheter insertion (safety cohort); 142 met eligibility criteria and were ablated (evaluable cohort). Confirmation of entrance block for all targeted pulmonary veins was achieved in 99.3% of patients. The primary AE rate was 4.0% (6/150), and 12-month success was 63.1% (95% confidence interval: 54.2%-71.4%). A non-significant trend towards higher success was observed in patients with isoproterenol/adenosine challenge vs. those without (73.1% vs. 60.2%, respectively; P=0.065). Investigators stayed within their pre-selected CF working range (catheter-tissue contact stability) 79.7% ± 12.7% of the time. When investigators stayed within the CF range ≥80% vs. <80% of the time, ablation success was 69.2% vs. 58.5%, respectively (P=0.285). QoL improved significantly at 6 months and was sustained through the 12-month follow-up (P<0.0001). CONCLUSIONS: Symptom control in a real-world setting of persAF ablation using the THERMOCOOL SMARTTOUCH® catheter was 63.1%, with significant improvements in QoL, and trended non-significantly towards increased success in patients receiving isoproterenol/adenosine challenge and when investigators stayed within their pre-selected CF range ≥80% of the time.

Characterization and significance of localized sources identified by a novel automated algorithm during mapping of human persistent atrial fibrillation.

BACKGROUND: Automated algorithms may identify focal (FA) and rotational (RoA) activations during persistent atrial fibrillation (PeAF). OBJECTIVE: To evaluate an automated algorithm for characterizing and assessing significance of FA/RoA. METHODS: Eighty-six PeAF ablation patients (1411 maps) were analyzed. Maps were obtained with a 64-electrode basket using CARTOFINDER, which filters/annotates atrial unipolar electrograms over 30 seconds. Operators ablated FA/RoA followed by pulmonary vein isolation (PVI). The automated algorithm was retrospectively applied using QS patterns to identify FA and sequential activation gradients for RoA without phase mapping. Algorithm-identified FA and RoA were validated against blinded adjudicators. Ablation of algorithm-identified FA/RoA was related to procedural AF termination. RESULTS: 73% ± 18% of electrodes (65% ± 11% atrial surface area) were adequate for analysis. Compared with adjudicators, the algorithm had a sensitivity of 84% for FA and 86% for RoA. There were 4 ± 2 FA and 2 ± 2 RoA per patient. FA occurred 8 ± 6 times during the 30-second window (cumulative duration 8 ± 6 seconds). RoA occurred 5 ± 3 times (median 2, consecutive rotations) with a cumulative duration of 3 ± 2 seconds. Compared to patients without procedural AF termination, patients with termination had more FA ablated (75% vs 38%, P = 0.006). AF termination was not predicted by percentage of RoA ablated although there was a trend towards a higher percentage of left atrial RoA ablated ( P = 0.06). CONCLUSION: An automated algorithm had high sensitivity for FA and RoA. Acute AF termination was associated with FA ablation but not RoA ablation. Future studies need to define the significance of FA and RoA and whether they are overlapping or separate mechanisms.