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Background and Aims: Patterns of atrial fibrillation (AF) recurrence post-catheter ablation for persistent AF (PsAF) are not well described. This study aimed to describe the pattern of AF recurrence seen following catheter ablation for PsAF and the implications for healthcare utilization and quality of life (QoL)., Methods: This was a post-hoc analysis of the CAPLA study, an international, multicentre study that randomized patients with symptomatic PsAF to pulmonary vein isolation plus posterior wall isolation or pulmonary vein isolation alone. Patients underwent twice daily single lead ECG, implantable device monitoring or three monthly Holter monitoring., Results: 154 of 333 (46.2%) patients (median age 67.3 years, 28% female) experienced AF recurrence at 12-month follow-up. Recurrence was paroxysmal in 97 (63%) patients and persistent in 57 (37%). Recurrence type did not differ between randomization groups (P = .508). Median AF burden was 27.4% in PsAF recurrence and .9% in paroxysmal AF (PAF) recurrence (P < .001). Patients with PsAF recurrence had lower baseline left ventricular ejection fraction (PsAF 50% vs. PAF 60%, P < .001) and larger left atrial volume (PsAF 54.2 ± 19.3 mL/m² vs. PAF 44.8 ± 11.6 mL/m², P = .008). Healthcare utilization was significantly higher in PsAF (45 patients [78.9%]) vs. PAF recurrence (45 patients [46.4%], P < .001) and lowest in those without recurrence (17 patients [9.5%], P < .001). Patients without AF recurrence had greater improvements in QoL as assessed by the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) questionnaire (Δ33.3 ± 25.2 points) compared to those with PAF (Δ24.0 ± 25.0 points, P = .012) or PsAF (Δ13.4 ± 22.9 points, P < .001) recurrence., Conclusions: AF recurrence is more often paroxysmal after catheter ablation for PsAF irrespective of ablation strategy. Recurrent PsAF was associated with higher AF burden, increased healthcare utilization and antiarrhythmic drug use. The type of AF recurrence and AF burden may be considered important endpoints in clinical trials investigating ablation of PsAF., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Aims: Pulsed field ablation (PFA) for the treatment of atrial fibrillation (AF) potentially offers improved safety and procedural efficiencies compared with thermal ablation. Opportunities remain to improve effective circumferential lesion delivery, safety, and workflow of first-generation PFA systems. In this study, we aim to evaluate the initial clinical experience with a balloon-in-basket, 3D integrated PFA system with a purpose-built form factor for pulmonary vein (PV) isolation., Methods and Results: The VOLT CE Mark Study is a pre-market, prospective, multi-centre, single-arm study to evaluate the safety and effectiveness of the Volt™ PFA system for the treatment of paroxysmal (PAF) or persistent AF (PersAF). Feasibility sub-study subjects underwent phrenic nerve evaluation, endoscopy, chest computed tomography, and cerebral magnetic resonance imaging. Study endpoints were the rate of primary serious adverse event within 7 days and acute procedural effectiveness. A total of 32 subjects (age 61.6 ± 9.6 years, 65.6% male, 84.4% PAF) were enrolled and treated in the feasibility sub-study and completed a 30-day follow-up. Acute effectiveness was achieved in 99.2% (127/128) of treated PVs (96.9% of subjects, 31/32) with 23.8 ± 4.2 PFA applications/subject. Procedure, fluoroscopy, LA dwell, and transpired ablation times were 124.6 ± 28.1, 19.8 ± 8.9, 53.0 ± 21.0, and 48.0 ± 19.9 min, respectively. Systematic assessments of initial safety revealed no phrenic nerve injury, pulmonary vein stenosis, or oesophageal lesions causally related to the PFA system and three subjects with silent cerebral lesions (9.4%). There were no primary serious adverse events., Conclusion: The initial clinical use of the Volt PFA System demonstrates acute safety and effectiveness in the treatment of symptomatic, drug refractory AF., Competing Interests: Conflict of interest P.S. reports serving on the medical advisory board for Abbott, Medtronic, Boston-Scientific, CathRx, and Pacemate. The University of Adelaide has received on behalf of P.S. research funds from Boston-Scientific, Medtronic, Abbott, and Becton Dickenson. S.H. reports teaching and consulting honorariums for Medtronic, Boston Scientific, Biotronik, and Johnson and Johnson. S.H. also serves on the medical advisory boards for Biotronik and Boston Scientific. The Victorian Heart Hospital has also received research funds from Boston Scientific, Medtronic, and Abbott on behalf of S.H. The University of Adelaide has received advisory and/or consulting fees on behalf of M.E. from Medtronic and Biosense Webster. E.K. reports serving on the medical advisory boards for Medtronic, Boston-Scientific, and Biotronik. A.M. is employed by Abbott. J.M.K. reports research and fellowship support from Medtronic, Biosense Webster, Abbott, and Zoll., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society ., Competing Interests: Conflict of interest: All members provided disclosure statements to assess potential conflicts of interest. Details are available in the Supplementary material., (This article has been co-published with permission in Europace, HeartRhythm, Journal of Arrhythmia and Journal of Interventional Cardiac Electrophysiology. © 2024 Heart Rhythm Society, the European Society of Cardiology, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society The articles are identical except for minor stylistic and spelling differences in keeping with each journal's style. Any citation can be used when citing this article.)

Aims: Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA)., Methods and Results: Eighty-three international experts met in Münster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to improve stroke risk prediction in patients with AF, especially in those with a low AF burden. Biomolecules, genetics, and imaging can support this. (iv) The presence of AF should trigger systematic workup and comprehensive treatment of concomitant cardiovascular conditions. (v) Machine learning algorithms have been used to improve detection or likely development of AF. Cooperation between clinicians and data scientists is needed to leverage the potential of data science applications for patients with AF., Conclusions: Patients with AF and a low arrhythmia burden have a lower risk of stroke and other cardiovascular events than those with a high arrhythmia burden. Combining active rhythm control, anticoagulation, rate control, and therapy of concomitant cardiovascular conditions can improve the lives of patients with AF., Competing Interests: Conflict of interest The 9th AFNET/EHRA consensus conference was partially supported by the European Union MAESTRIA project (grant agreement 965286) to AFNET. The following participants and authors are employees of companies active in cardiovascular health as indicated in their affiliations: M.D.M., E.D., C.E., G.H., L.H.H., T.H., R.H.v.L., M.W., and H.W. P.K. was partially supported by the European Union AFFECT-AF (grant agreement 847770) and MAESTRIA (grant agreement 965286), German Center for Cardiovascular Research supported by the German Ministry of Education and Research (DZHK, grant numbers DZHK FKZ 81X2800182, 81Z0710116, and 81Z0710110), German Research Foundation (Ki 509167694), and Leducq Foundation. He receives research support for basic, translational, and clinical research projects from several drug and device companies active in AF and has received honoraria from several such companies in the past, but not in the last 3 years. He is listed as an inventor on two issued patents held by the University of Hamburg (Atrial Fibrillation Therapy WO 2015140571, Markers for Atrial Fibrillation WO 2016012783). J.G.A. was partially supported by the Canadian Arrhythmia Network and the Michael Smith Foundation for Health Research, Baylis Medical. He receives consulting fees/honoraria from Bayer, BMS/Pfizer Alliance, Servier, and Medtronic Inc. E.A. receives consulting fees/honoraria from Biosense Webster and Bayer. G.B. receives consulting fees/honoraria from Bayer, BMS, Boston Scientific, Daiichi Sankyo, Sanofi, and Janssen. A.J.C. receives consulting fees/honoraria from Bayer, Pfizer/BMS, Daiichi Sankyo, Menarini, Sanofi, Boston Scientific, Biosense Webster, Abbott, Acesion Pharma, Huya Bio, and Milestone. V.C. receives consulting fees/honoraria from Bayer, Boehringer Ingelheim, and Ever Pharma (paid to the institution of employment). W.D. receives consulting fees/honoraria from Reata and research grants from MicroPort, Boston Scientific, and Abbott. S.Z.D. receives consulting fees from BMS/Pfizer, Cortrium, and Acesion Pharma and speaker fees from MS/Pfizer and Bayer. He is listed as a medical advisor for Vital Beats. Dobromir D. receives consulting fees/honoraria from Elsevier, Springer Healthcare Ltd, and Daiichi Sankyo and research grants as follows: four NIH grants (partially) from Baylor College of Medicine, Houston; one NIH grant from UC Davis, one NIH grant from the University of Minnesota, and one EU-Project H2020. David D. receives consulting fees/honoraria from Abbott, Astra Zeneca, Biotronik, Boehringer Ingelheim, Boston Scientific, BMS/Pfizer, CVRx, Medtronic, MicroPort, and Zoll and research grants from Roche, CVRx, and Zoll. L.E. has received lecture fees from various companies in AF in the past but none related to the present work. L.F. receives consulting fees/honoraria from Roche (paid to the institution of employment). She is currently employed at the UKE and previously at the University of Birmingham. She was partially supported by the European Union AFFECT-EU (grant agreement 847770), MAESTRIA (grant agreement 965286), CATCH ME (grant agreement 633196), and the British Heart Foundation (AA/18/2/3218). D.F.-R. receives research grants from Abbott. He is listed as an inventor on two issued patents: EP3636147A1 (method for the identification of cardiac fibrillation drivers and/or the footprint of rotational activations) and PCT/EP2022/071364 (system and method of assessment of electromechanical remodelling). A.G. receives consulting fees/honoraria from Daiichi Sankyo, Bayer, BMS/Pfizer, Medtronic, Abbott, and Boston Scientific and was partially supported by the European Union MAESTRIA (grant agreement 965286). K.G.H. receives consulting fees/honoraria from Abbott, Alexion, Amarin, Astra Zeneca, Bayer Healthcare, Biotronik, Boehringer Ingelheim, Boston Scientific, BMS/Pfizer, Daiichi Sankyo, Edwards Lifesciences, Medtronic, Novaris, Portola, Premier Research, Sanofi, SUN Pharma, and W. L. Gore and Associates. J.S.H. receives speaking fees from BMS/Pfizer, Bayer, Servier, and Boston Scientific and consulting fees from Bayer and Boston Scientific. He receives research grants from BMS/Pfizer, Servier, Novartis, Boston Scientific, and Medtronic. H.H. receives lecture and consulting fees from Bayer, Biotronik, BMS/Pfizer, Daiichi Sankyo, Milestone Pharmaceuticals, Centrix India, C.T.I. Germany, ESC, Medscape, and Springer Healthcare Ltd. He receives research grants (paid to the institution of employment, University of Antwerp and/or University of Hasselt) from Abbott, Bayer, Biosense Webster, Boston Scientific, Daiichi Sankyo, Fibricheck/Qompium, Medtronic, and BMS/Pfizer. Z.H. receives consulting fees/honoraria from Boehringer Ingelheim, BMS/Pfizer, and Roche Diagnostics. He was partially supported by The Swedish Society for Medical Research (S17-0133), Hjärt-Lungfonden (The Swedish Heart-Lung Foundation, 20200722), and the institution he is currently employed at (Uppsala University Hospital). L.H.-M. receives research grants from the Spanish Ministry of Science and Innovation (PID2020-116927RB-C21) and Fondo Europeo de Desarrollo Regional (FEDER). D.K. receives consulting fees/honoraria from Bayer, Amomed, and Protherics Medicines Development. He receives research grants from the National Institute for Health Research (NIHR CDF-2015-08-074 RAE-AF; NIHR130280 DaRe2THINK; NIHR13274 D2T-NeuroVascular; and NIHR203326 Biomedical Research Centre), the British Heart Foundation (PG/17/55/33087, AA/182/3218, and FS/CDRF/21/21032), the EU/EFPIA Innovative Medicines Initiative (BigData@Heart 116074), EU Horizon and UKRI (HYPERMARKER 101095480) UK National Health Service—Data for R&D-Subnational Secure Data Environment programme, UK Department for Business, Energy Industrial Strategy Regulators Pioneer Fund, the Cook & Wolstenholme Charitable Trust, and the European Society of Cardiology supported by educational grants from Boehringer Ingelheim, BMS/Pfizer, Alliance, Bayer, Daiichi Sankyo, Boston Scientific, the NIHR/University of Oxford Biomedical Research Centre, and the British Hear Foundation, the University of Birmingham Accelerator Award (STEEER-AF). J.L.M. receives consulting fees/honoraria from Biotronik, Medtronic, MicroPort, and Milestone Pharmaceuticals. A.M. receives consulting fees/honoraria from Medtronic, Biosense Webster, and Boston Scientific and lecture fees from Medtronic, Boston Scientific, Biosense Webster, BMS, and Bayer. L.M. receives consulting fees/honoraria from Abbott, Medtronic, Boston Scientific, and Johnson & Johnson. G.A.N. receives lecture fees from AliveCor, consultant fees from Biosense Webster, and research grants from Abbott and Biosense Webster. H.P. receives consulting fees/honoraria from Abbott, Boston Scientific, Biosense Webster, Medtronic, Daiichi Sankyo, Bayer, and Pfizer. P.S. receives consulting fees/honoraria from Medtronic, Boston Scientific, Abbott, CathRx, and PaceMate (paid to the institution of employment). He is currently employed at the University of Adelaide, which receives research grants from Medtronic, Boston Scientific, and Becton-Dickenson. R.B.S. receives consulting fees/honoraria from BMS/Pfizer. She was partially supported by the European Union Horizon 2020 research and innovation programme (grant agreement 648131 and 847770), German Center for Cardiovascular Research supported by the German Ministry of Education and Research (DZHK, grant numbers 81Z1710103 and 81Z0710114), German Ministry of Research and Education (BMBF 01ZX1408A), ERACoSysMed3 (031L0239), Wolfgang Seefried project funding German Heart Foundation. U.S. receives consulting fees/honoraria from University Svizzerra Italiana, Stanford, and Johnson & Johnson and research grants from the European Union, Dutch Heart Foundation, Roche, and EP Solution. He is a shareholder of YourRhythmics B.V. T.T. receives consulting fees/honoraria from Boston Scientific and Medtronic. I.C.v.G. receives consulting fees/honoraria from Bayer (paid to the institution of employment). She is currently employed at the University of Groningen. K.V. receives consulting fees/honoraria from Abbott, Philips, Medtronic, Biosense Webster, and Boston Scientific and research grants from Medtronic and Biosense Webster. R.W. receives consulting fees/honoraria from Boehringer Ingelheim, BMS/Pfizer, Daiichi Sankyo, Boston Scientific, Biotronik, Abiomed, and Zoll and a research grant from Boston Scientific, BMS/Pfizer, and Abiomed. S.W. receives consulting fees/honoraria from Boehringer Ingelheim, Boston Scientific, Abbott, and Bayer Vital and a research grant from Boston Scientific. All remaining authors (G.B., J.C.N., T.D.P., N.D., M.F., E.G., S.H., S.K., D.L., K.M.-R., M.O., A.S.P., U.R., M.R., D.S., C.S., G.S., D.S., S.T., R.H.v.L., and S.Z.) have declared no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background and Aims: Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression. No randomized studies have evaluated the impact of the ablation energy on progression to persistent atrial tachyarrhythmia., Methods: Three hundred forty-six patients with drug-refractory paroxysmal AF were enrolled and randomly assigned to contact-force-guided RF ablation (CF-RF ablation, 115), 4 min cryoballoon ablation (CRYO-4, 115), or 2 min cryoballoon ablation (CRYO-2, 116). Implantable cardiac monitors placed at study entry were used for follow-up. The main outcome was the first episode of persistent atrial tachyarrhythmia. Secondary outcomes included atrial tachyarrhythmia recurrence and arrhythmia burden on the implantable monitor., Results: At a median of 944.0 (interquartile range [IQR], 612.5-1104) days, 0 of 115 patients (0.0%) randomly assigned to CF-RF, 8 of 115 patients (7.0%) assigned to CRYO-4, and 5 of 116 patients (4.3%) assigned to CRYO-2 experienced an episode of persistent atrial tachyarrhythmia (P = .03). A documented recurrence of any atrial tachyarrhythmia ≥30 s occurred in 56.5%, 53.9%, and 62.9% of those randomized to CF-RF, CRYO-4, and CRYO-2, respectively; P = .65. Compared with that of the pre-ablation monitoring period, AF burden was reduced by a median of 99.5% (IQR 94.0%, 100.0%) with CF-RF, 99.9% (IQR 93.3%-100.0%) with CRYO-4, and 99.1%% (IQR 87.0%-100.0%) with CRYO-2 (P = .38)., Conclusions: Catheter ablation of paroxysmal AF using radiofrequency energy was associated with fewer patients developing persistent AF on follow-up., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: Exercise training reduces recurrence of arrhythmia and symptom severity amongst patients with symptomatic, non-permanent atrial fibrillation (AF). However, there is little evidence on whether this effect is modified by patient sex. In a sub-analysis from the ACTIVE-AF (A Lifestyle-based, PhysiCal AcTIVity IntErvention for Patients With Symptomatic Atrial Fibrillation) randomized controlled trial, we compared the effects of exercise training on AF recurrence and symptom severity between men and women., Methods and Results: The ACTIVE-AF study randomized 120 patients (69 men, 51 women) with paroxysmal or persistent AF to receive an exercise intervention combining supervised and home-based aerobic exercise over 6 months or to continue standard medical care. Patients were followed over a 12-month period. The co-primary outcomes were recurrence of AF, off anti-arrhythmic medications and without catheter ablation, and AF symptom severity scores. By 12 months, recurrence of AF was observed in 50 (73%) men and 34 (67%) women. In an intention-to-treat analysis, there was a between-group difference in favour of the exercise group for both men [hazard ratio (HR) 0.52, 95% confidence interval (CI): 0.29-0.91, P = 0.022] and women (HR 0.47, 95% CI: 0.23-0.95, P = 0.035). At 12 months, symptom severity scores were lower in the exercise group compared with controls amongst women but not for men., Conclusion: An exercise-based intervention reduced arrhythmia recurrence for both men and women with symptomatic AF. Symptom severity was reduced with exercise in women at 12 months. No difference was observed in symptom severity for men., Registration: Australia and New Zealand Clinical Trials Registry: ACTRN12615000734561., Competing Interests: Conflict of interest: C.V.V. reports lecture and/or consulting fees from Novartis. R.M. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Abbott, Pfizer, and Bayer. R.M. reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott, and Bayer. D.H.L. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Abbott Medical, Boehringer Ingelheim, Bayer, and Pfizer. P.S. reports having served on the advisory board of Boston Scientific, CathRx, Medtronic, Abbott Medical, and PaceMate. P.S. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Boston Scientific, Abbott Medical, PaceMate, and CathRx. P.S. reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific, PaceMate, and Becton Dickinson. All other authors have no disclosures., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Lifestyle risk factors are a modifiable target in atrial fibrillation (AF) management. The relative contribution of individual lifestyle risk factors to AF development has not been described. Development and validation of an AF lifestyle risk score to identify individuals at risk of AF in the general population are the aims of the study., Methods and Results: The UK Biobank (UKB) and Framingham Heart Study (FHS) are large prospective cohorts with outcomes measured >10 years. Incident AF was based on International Classification of Diseases version 10 coding. Prior AF was excluded. Cox proportional hazards regression identified independent AF predictors, which were evaluated in a multivariable model. A weighted score was developed in the UKB and externally validated in the FHS. Kaplan-Meier estimates ascertained the risk of AF development. Among 314 280 UKB participants, AF incidence was 5.7%, with median time to AF 7.6 years (interquartile range 4.5-10.2). Hypertension, age, body mass index, male sex, sleep apnoea, smoking, and alcohol were predictive variables (all P < 0.001); physical inactivity [hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.96-1.05, P = 0.80] and diabetes (HR 1.03, 95% CI 0.97-1.09, P = 0·38) were not significant. The HARMS2-AF score had similar predictive performance [area under the curve (AUC) 0.782] to the unweighted model (AUC 0.802) in the UKB. External validation in the FHS (AF incidence 6.0% of 7171 participants) demonstrated an AUC of 0.757 (95% CI 0.735-0.779). A higher HARMS2-AF score (≥5 points) was associated with a heightened AF risk (score 5-9: HR 12.79; score 10-14: HR 38.70). The HARMS2-AF risk model outperformed the Framingham-AF (AUC 0.568) and ARIC (AUC 0.713) risk models (both P < 0.001) and was comparable to the CHARGE-AF risk score (AUC 0.754, P = 0.73)., Conclusion: The HARMS2-AF score is a novel lifestyle risk score which may help identify individuals at risk of AF in the general community and assist population screening., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: Over the past 25 years there has been a substantial development in the field of digital electrophysiology (EP) and in parallel a substantial increase in publications on digital cardiology.In this celebratory paper, we provide an overview of the digital field by highlighting publications from the field focusing on the EP Europace journal., Results: In this journey across the past quarter of a century we follow the development of digital tools commonly used in the clinic spanning from the initiation of digital clinics through the early days of telemonitoring, to wearables, mobile applications, and the use of fully virtual clinics. We then provide a chronicle of the field of artificial intelligence, a regulatory perspective, and at the end of our journey provide a future outlook for digital EP., Conclusion: Over the past 25 years Europace has published a substantial number of papers on digital EP, with a marked expansion in digital publications in recent years., Competing Interests: Conflict of interest: ES declares lecture fees from Bayer, Bristol-Myers Squibb-Pfizer, Boehringer- Ingelheim, Johnson & Johnson, Merck Sharp & Dohme PS is supported by an Investigator Grant from the National Health and Medical Research Council of Australia. Conflict of Interest Disclosures: PS reports having served on the advisory board of Boston Scientific, CathRx, Medtronic, Abbott Medical and Pacemate. PS reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Boston-Scientific, and Abbott Medical, Pacemate and CathRx. PS reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston-Scientific, Pacemate, Becton Dickinson and Microport. JH reports advisory board: iRhythm Technologies Consultant: Abbott Medical Lectureship fees: Medtronic & 91 Life/ScottCare EC, LD, FER., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Catheter ablation is an effective strategy in atrial fibrillation (AF). However, its timing in the course of management remains unclear. The aim of this study was to determine if an early vs. delayed AF ablation strategy is associated with differences in arrhythmia outcomes during 12-month follow-up., Methods and Results: One hundred patients with symptomatic AF referred to a tertiary centre for management were randomized in a 1:1 ratio to either an early ablation strategy (within 1 month of recruitment) or a delayed ablation strategy (optimized medical therapy followed by catheter ablation at 12 months post recruitment). The primary endpoint was atrial arrhythmia free survival at 12 months post-ablation. Secondary outcomes included: (i) AF burden, (ii) AF burden by AF phenotype, and (iii) antiarrhythmic drug (AAD) use at 12 months. Overall, 89 patients completed the study protocol (Early vs. Delayed: 48 vs. 41). Mean age was 59 ± 12.9 years (29% women). Pulmonary vein isolation was achieved in 100% of patients. At 12 months, 56.3% of patients in the early ablation group were free from recurrent arrhythmia, compared with 58.6% in the delayed ablation group (HR 1.12, 95% CI 0.59-2.13, P = 0.7). All secondary outcomes showed no significant difference including median AF burden (Early vs. Delayed: 0% [IQR 3.2] vs. 0% [5], P = 0.66), median AF burden amongst paroxysmal AF patients (0% [IQR 1.1] vs. 0% [4.5], P = 0.78), or persistent AF patients (0% [IQR 22.8] vs. 0% [5.6], P = 0.45) or AAD use (33% vs. 37%, P = 0.8)., Conclusion: Compared with an early ablation strategy, delaying AF ablation by 12 months for AAD management did not result in reduced ablation efficacy., Competing Interests: Conflict of interest All authors declare no conflict of interest for this contribution., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Aims: Implantable cardioverter defibrillators (ICDs) prevent sudden cardiac death. Anxiety, depression, and post-traumatic stress disorder (PTSD) are underappreciated symptoms. We aimed to systematically synthesize prevalence estimates of mood disorders and symptom severities, pre- and post-ICD insertions. Comparisons were made with control groups, as well as within ICD patients by indication (primary vs. secondary), sex, shock status, and over time., Methods: Databases (Medline, PsycINFO, PubMed, and Embase) were searched without limits from inception to 31 August 2022; 4661 articles were identified, 109 (39 954 patients) of which met criteria., Results: Random-effects meta-analyses revealed clinically relevant anxiety in 22.58% (95%CI 18.26-26.91%) of ICD patients across all timepoints following insertion and depression in 15.42% (95%CI 11.90-18.94%). Post-traumatic stress disorder was seen in 12.43% (95%CI 6.90-17.96%). Rates did not vary relative to indication group. Clinically relevant anxiety and depression were more likely in ICD patients who experienced shocks [anxiety odds ratio (OR) = 3.92 (95%CI 1.67-9.19); depression OR = 1.87 (95%CI 1.34-2.59)]. Higher symptoms of anxiety were seen in females than males post-insertion [Hedges' g = 0.39 (95%CI 0.15-0.62)]. Depression symptoms decreased in the first 5 months post-insertion [Hedges' g = 0.13 (95%CI 0.03-0.23)] and anxiety symptoms after 6 months [Hedges' g = 0.07 (95%CI 0-0.14)]., Conclusion: Depression and anxiety are highly prevalent in ICD patients, especially in those who experience shocks. Of particular concern is the prevalence of PTSD following ICD implantation. Psychological assessment, monitoring, and therapy should be offered to ICD patients and their partners as part of routine care., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Competing Interests: Conflicts of interest: The authors have provided declaration of interest information for all relationships that might be perceived as real or potential sources of conflicts of interest. The full disclosures can be viewed in the Supplementary material online for this article, available online at [URL].

Aims: This study aimed to investigate the impact of sex on the clinical profile, utilization of rhythm control therapies, cost of hospitalization, length of stay, and in-hospital mortality in patients admitted for atrial fibrillation (AF) in the United States., Methods and Results: We used data from the Nationwide Inpatient Sample for the year 2018. Regression analysis was performed to investigate differences between men and women. A P-value ≤ 0.05 was considered significant. We included 82592 patients with a primary diagnosis of of AF 50.8% women. Women were significantly older (mean age 74 vs. 67 years, P < 0.001) and had a higher CHA2DS2-VASc score (median 4 vs. 2, P < 0.001) than men. Women had relatively higher in-hospital mortality (0.9% vs. 0.8%, P = 0.070); however, after adjustment for known risk factors female sex was no longer a predictor of mortality (P = 0.199). In sex-specific regression analyses, increased age, chronic obstructive pulmonary disease, previous stroke, heart failure, and chronic kidney disease were risk factors for in-hospital mortality in both sexes, vascular disease only in women, and race and alcohol abuse only in men. After adjusting for potential confounders, female sex was associated with lower likelihood of receiving catheter ablation [adjusted odds ratio (aOR) 0.69, 95% confidence interval (CI) 0.64-0.74] and electrical cardioversion (aOR 0.69, 95% CI 0.67-0.72), and with longer hospitalization (aOR 1.33, 95% CI 1.28-1.37), whereas sex had no influence on hospitalization costs (P = 0.339)., Conclusion: There were differences in the risk profile, management, and outcomes between men and women hospitalized for AF. Further studies are needed to explore why women are treated differently regarding rhythm control procedures., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Competing Interests: Conflict of interest: J.M.H. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic and Pfizer/BMS. P.S. reports having served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, Pacemate, and CathRx. P.S. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Boston Scientific, and Abbott Medical. P.S. reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific, and MicroPort. D.H.L. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Abbott Medical, Bayer, Biotronik, Boehringer Ingelheim, Medtronic, MicroPort and Pfizer. All other authors declared no conflict of interest.

Aims: There is a paucity of epidemiological evidence on alcohol and the risk of bradyarrhythmias. We thus characterized associations of total and beverage-specific alcohol consumption with incident bradyarrhythmias using data from the UK Biobank., Methods and Results: Alcohol consumption reported at baseline was calculated as UK standard drinks (8 g alcohol)/week. Bradyarrhythmia events were defined as sinus node dysfunction (SND), high-level atrioventricular block (AVB), and permanent pacemaker implantations. Outcomes were assessed through hospitalization and death records, and dose-response associations were characterized using Cox regression models with correction for regression dilution bias. We studied 407 948 middle-aged individuals (52.4% female). Over a median follow-up time of 11.5 years, a total of 8 344 incident bradyarrhythmia events occurred. Increasing total alcohol consumption was not associated with an increased risk of bradyarrhythmias. Beer and cider intake were associated with increased bradyarrhythmia risk up to 12 drinks/week; however, no significant associations were observed with red wine, white wine, or spirit intake. When bradyarrhythmia outcomes were analysed separately, a negative curvilinear was observed for total alcohol consumption and risk of SND, but no clear association with AVB was observed., Conclusion: In this predominantly White British cohort, increasing total alcohol consumption was not associated with an increased risk of bradyarrhythmias. Associations appeared to vary according to the type of alcoholic beverage and between different types of bradyarrhythmias. Further epidemiological and experimental studies are required to clarify these findings., Competing Interests: Conflict of interest: J.M.L.H. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic and Pfizer/BMS. D.H.L. reports the University of Adelaide has received on his behalf lecture and/or consulting fees from Abbott Medical, Bayer, Biotronik, Boehringer Ingelheim, Medtronic, Microport, and Pfizer/BMS. P.S. reports having served on the advisory board of Medtronic, Abbott Medical, Boston Scientific, CathRx, and PaceMate. P.S. reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Abbott Medical, and Boston Scientific. P.S. reports that the University of Adelaide has received on his behalf research funding from Medtronic, Abbott Medical, Boston Scientific, and Microport. C.X.W. reports that the University of Adelaide has received on his behalf lecture, travel, and/or research funding from Abbott Medical, Bayer, Boehringer Ingelheim, Medtronic, Novartis, Servier, St Jude Medical, and Vifor Pharma. The other authors have nothing to disclose., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: The prevalence of atrial fibrillation (AF) is increasing rapidly with the growing utilization of catheter ablation (CA) as a treatment strategy. Education for individuals undertaking this procedure is diverse, with varying degrees of information provided and little standardization. Many individuals utilize the internet as an educational resource. However, there is limited regulation of online patient information. To evaluate the quality of web-based patient education resources for patients undergoing CA for AF., Methods and Results: A cross-sectional observational study was performed to obtain all freely accessible online educational resources about CA for AF from inception until 1 October 2019. Search engines used: Google, Yahoo!, and Bing. The Patient Education Materials Assessment Tool (PEMAT) was used to evaluate the quality of web-based patient education materials and printable tools. The PEMAT score objectively measures both the understandability and actionability of educational material. A total of 17 websites and 15 printable sources were included in the analysis. Non-government organizations developed 19% of materials and 75% were created by private or university hospitals. Nineteen sources (59.4%) were rated as highly understandable: 9 websites (52.9%) and 10 printable tools (66.7%). Seven sources (21.9%) were rated as highly actionable: 6 (35.3%) websites and 1 (6.7%) printable tool., Conclusion: The overall understandability of educational CA material was high, whilst improvement of actionability is warranted. The addition of summaries, visual aids, and tools, such as checklists may improve quality. These findings have significant implications for the development of patient educational material for CA in AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Aims: In atrial fibrillation (AF) patients, untreated sleep-disordered breathing (SDB) is associated with lower success rates of rhythm control strategies and as such structured SDB testing is recommended. Herein, we describe the implementation of a virtual SDB management pathway in an AF outpatient clinic and examine the utility and feasibility of this new approach., Methods and Results: Prospectively, consecutive AF patients accepted for AF catheter ablation procedures without previous diagnosis of SDB were digitally referred to a virtual SDB management pathway and instructed to use WatchPAT-ONE (ITAMAR) for one night. Results were automatically transferred to a virtual sleep laboratory, upon which a teleconsultation with a sleep physician was planned. Patient experience was measured using surveys. SDB testing was performed in 119 consecutive patients scheduled for AF catheter ablation procedures. The median time from digital referral to finalization of the sleep study report was 18 [11-24] days. In total, 65 patients (55%) were diagnosed with moderate-to-severe SDB. Patients with SDB were prescribed more cardiovascular drugs and had higher body mass indices (BMI, 29 ± 3.3 vs. 27 ± 4.4kg/m2, P < 0.01). Patients agreed that WatchPAT-ONE was easy to use (91%) and recommended future use of this virtual pathway in AF outpatient clinics (86%). Based on this remote SDB testing, SDB treatment was recommended in the majority of patients., Conclusion: This novel virtual AF management pathway allowed remote SDB testing in AF outpatient clinics with a short time to diagnosis and high patient satisfaction. Structured SDB testing results in a high detection of previously unknown SDB in AF patients scheduled for AF ablation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Aims: The aim of this study is to summarize data from prospective cohort studies on clinical predictors of stroke and systemic embolism in anticoagulant-naïve atrial fibrillation (AF) patients., Methods and Results: EMBASE, MEDLINE, Global Index Medicus, and Web of Science were searched to identify all studies published by 28 November 2019. Forty-seven studies reporting data from 1 756 984 participants in 15 countries were included. The pooled incidence of stroke in anticoagulant-naïve AF patients was 23.8 per 1000 person-years (95% CI 19.7-28.2). Older age was associated with incident stroke or systemic embolism, with a pooled hazard ratio (HR) of 2.14 (95% CI 1.85-2.47), 2.83 (95% CI 2.27-3.51), and 6.87 (95% CI 6.33-7.44) for age 65-75, ≥75, and ≥85 years, respectively. Other predictors of stroke or systemic embolism included history of stroke or TIA (HR 2.84, 95% CI 2.19-3.67), hypertension (HR 1.60, 95% CI 1.37-1.86), diabetes (HR 1.28, 95% CI 1.20-1.37), heart failure (HR 1.25, 95% CI 1.11-1.40), peripheral artery disease (pooled HR 1.35, 95% CI 1.04-1.75), vascular disease (pooled HR 1.21, 95% CI 1.06-1.39), and prior myocardial infarction (pooled HR 1.08, 95% CI 1.03-1.14). Female sex was a predictor of thromboembolism in studies outside Asia (HR 1.35, 95% CI 1.15-1.59), but not in those done in Asia (HR 0.95, 95% CI 0.81-1.10)., Conclusion: This study confirms age and prior stroke as the strongest predictors of stroke or systemic embolism in anticoagulant-naive AF patients. Other predictors include hypertension, diabetes, heart failure, and vascular disease. Female sex seems not to be universally associated with stroke or systemic embolism., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Dietary intake has been shown to change the composition of gut microbiota and some changes in microbiota (dysbiosis) have been linked to diabetes, hypertension, and obesity, which are established risk factors for atrial fibrillation (AF). In addition, intestinal dysbiosis generates microbiota-derived bioactive metabolites that might exert proarrhythmic actions. Although emerging preclinical investigations and clinical observational cohort studies suggest a possible role of gut dysbiosis in AF promotion, the exact mechanisms through which dysbiosis contributes to AF remain unclear. This Viewpoint article briefly reviews evidence suggesting that abnormalities in the intestinal microbiota play an important and little-recognized role in the pathophysiology of AF and that an improved understanding of this role may open up new possibilities in the management of AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Aims: The aim of this study is to determine the association between the coronavirus disease 2019 (COVID-19) pandemic and atrial fibrillation (AF) occurrence in individuals with cardiac implantable electronic devices (CIEDs)., Method and Results: Multi-centre, observational, cohort study over a 100-day period during the COVID-19 pandemic (COVID-19) in the USA. Remote monitoring was used to assess AF episodes in patients with a CIED (pacemaker or defibrillator; 20 centres, 13 states). For comparison, the identical 100-day period in 2019 was used (Control). The primary outcomes were the AF burden during the COVID-19 pandemic, and the association of the pandemic with AF occurrence, as compared with 1 year prior. The secondary outcome was the association of AF occurrence with per-state COVID-19 prevalence. During COVID-19, 10 346 CIEDs with an atrial lead were monitored. There were 16 570 AF episodes of ≥6 min transmitted (16 events per 1000 patient days) with a significant increase in proportion of patients with AF episodes in high COVID-19 prevalence states compared with low prevalence states [odds ratio 1.34, 95% confidence interval (CI) 1.21-1.48, P < 0.001]. There were significantly more AF episodes during COVID-19 compared with Control [incident rate ratio (IRR) 1.33, 95% CI 1.25-1.40, P < 0.001]. This relationship persisted for AF episodes ≥1 h (IRR 1.65, 95% CI 1.53-1.79, P < 0.001) and ≥6 h (IRR 1.54, 95% CI 1.38-1.73, P < 0.001)., Conclusion: During the first 100 days of COVID-19, a 33% increase in AF episodes occurred with a 34% increase in the proportion of patients with AF episodes observed in states with higher COVID-19 prevalence. These findings suggest a possible association between pandemic-associated social disruptions and AF in patients with CIEDs., Clinical Trial Registration: Australian New Zealand Clinical Trial Registry: ACTRN12620000692932., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Aims: There are conflicting data as to the impact of procedural volume on outcomes with specific reference to the incidence of major complications after catheter ablation for atrial fibrillation. Questions regarding minimum volume requirements and whether these should be per centre or per operator remain unclear. Studies have reported divergent results. We performed a systematic review and meta-analysis of studies reporting the relationship between either operator or hospital atrial fibrillation (AF) ablation volumes and incidence of complications., Methods and Results: Databases were searched for studies describing the relationship between operator or hospital AF ablation volumes and incidence of complications which were published prior to 12 June 2020. Of 1593 articles identified, 14 (315 120 patients) were included in the meta-analysis. Almost two-thirds of the procedures were performed in low-volume centres. Both hospital volume of ≥50 and ≥100 procedures/year were associated with a significantly lower incidence of complications compared to <50/year (4.2% vs. 5.5%, OR = 0.58, 95% CI 0.50-0.66, P < 0.001) or <100/year (5.5% vs. 6.2%, OR = 0.62, 95% CI 0.53-0.73, P < 0.001), respectively. Hospitals performing ≥50 procedures/year demonstrated significantly lower mortality compared with those performing <50 procedures/year (0.16% vs. 0.55%, OR = 0.33, 95% CI 0.26-0.43, P < 0.001). A similar relationship existed between proceduralist volume of <50/year and incidence of complications [3.75% vs. 12.73%, P < 0.001; OR = 0.27 (0.23-0.32)]., Conclusion: There is an inverse relationship between both hospital and proceduralist AF ablation volume and the incidence of complications. Implementation of minimum hospital and operator AF ablation volume standards should be considered in the context of a broader strategy to identify AF ablation Centers of Excellence., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Aims: Obstructive sleep apnoea (OSA) associates with atrial fibrillation (AF), but the relationship of OSA severity and AF phenotype with the atrial substrate remains poorly defined. We sought to define the atrial substrate across the spectrum of OSA severity utilizing high-density mapping., Methods and Results: Sixty-six consecutive patients (male 71%, age 61 ± 9) having AF ablation (paroxysmal AF 36, persistent AF 30) were recruited. All patents underwent formal overnight polysomnography and high-density left atrial (LA) mapping (mean 2351 ± 1244 points) in paced rhythm. Apnoea-hypopnoea index (AHI) (mean 21 ± 18) associated with lower voltage (-0.34, P = 0.005), increased complex points (r = 0.43, P < 0.001), more low-voltage areas (r = 0.42, P < 0.001), and greater voltage heterogeneity (r = 0.39, P = 0.001), and persisted after multivariable adjustment. Atrial conduction heterogeneity (r = 0.24, P = 0.025) but not conduction velocity (r = -0.09, P = 0.50) associated with AHI. Patchy regions of low voltage that co-localized with slowed conduction defined the atrial substrate in paroxysmal AF, while a diffuse atrial substrate predominated in persistent AF. The association of AHI with remodelling was most apparent among paroxysmal AF [LA voltage: paroxysmal AF -0.015 (-0.025, -0.005), P = 0.004 vs. persistent AF -0.006 (-0.017, 0.005), P = 0.30]. Furthermore, in paroxysmal AF an AHI ≥ 30 defined a threshold at which atrial remodelling became most evident (nil-mild vs. moderate vs. severe: 1.92 ± 0.42 mV vs. 1.84 ± 0.28 mV vs. 1.34 ± 0.41 mV, P = 0.006). In contrast, significant remodelling was observed across all OSA categories in persistent AF (1.67 ± 0.55 mV vs. 1.50 ± 0.66 mV vs. 1.55 ± 0.67 mV, P = 0.82)., Conclusion: High-density mapping observed that OSA associates with marked atrial remodelling, predominantly among paroxysmal AF cohorts with severe OSA. This may facilitate the identification of AF patients that stand to derive the greatest benefit from OSA management., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

The management of atrial fibrillation (AF) is multifaceted and treatment paradigms have changed significantly in the last century. The treatment of AF requires a comprehensive approach which goes beyond the treatment of the arrhythmia alone. Risk factor management has been introduced as a crucial pillar of AF management. As a result, the landscape of care delivery is changing as well, and novel models of comprehensive care delivery for AF have been introduced. This article reviews the evidence for the role of risk factor management in AF, how this can be integrated and implemented in clinical practice by applying novel models of care delivery, and finally identifies areas for ongoing research and potential healthcare reform to comprehensively manage the burgeoning AF population., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

of the progress in arrhythmias in 2020. RACE4 and ALL-IN indicated that integrated nurse-led care improves outcomes in AF patients.3,4 The same was reported for early rhythm control therapy15 and cryoablation as initial AF treatment.25,26 Subcutaneous ICD was non-inferior to classical transvenous ICD therapy in PRAETORIAN.54 One mechanistic study showed that autoantibodies against misexpressed actin, keratin, and connexin-43 proteins create a blood-borne biomarker profile enhancing diagnosis of Brugada syndrome.50 Another mechanistic study indicated that transseptal LV pacing yields similar improvement in contractility as His bundle pacing whilst being more easy to execute.44 In PRE-DETERMINE a simple-to-use ECG risk score improved risk prediction in patients with ischemic heart disease possibly enhancing appropriate ICD therapy in high risk patients.58., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2021. For permissions, please email: journals.permissions@oup.com.)

Chronic obstructive pulmonary disease (COPD) is highly prevalent among patients with atrial fibrillation (AF), shares common risk factors, and adds to the overall morbidity and mortality in this population. Additionally, it may promote AF and impair treatment efficacy. The prevalence of COPD in AF patients is high and is estimated to be ∼25%. Diagnosis and treatment of COPD in AF patients requires a close interdisciplinary collaboration between the electrophysiologist/cardiologist and pulmonologist. Differential diagnosis may be challenging, especially in elderly and smoking patients complaining of unspecific symptoms such as dyspnoea and fatigue. Routine evaluation of lung function and determination of natriuretic peptides and echocardiography may be reasonable to detect COPD and heart failure as contributing causes of dyspnoea. Acute exacerbation of COPD transiently increases AF risk due to hypoxia-mediated mechanisms, inflammation, increased use of beta-2 agonists, and autonomic changes. Observational data suggest that COPD promotes AF progression, increases AF recurrence after cardioversion, and reduces the efficacy of catheter-based antiarrhythmic therapy. However, it remains unclear whether treatment of COPD improves AF outcomes and which metric should be used to determine COPD severity and guide treatment in AF patients. Data from non-randomized studies suggest that COPD is associated with increased AF recurrence after electrical cardioversion and catheter ablation. Future prospective cohort studies in AF patients are needed to confirm the relationship between COPD and AF, the benefits of treatment of either COPD or AF in this population, and to clarify the need and cost-effectiveness of routine COPD screening., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: Our objective was to determine the ventricular arrhythmia burden in implantable cardioverter-defibrillator (ICD) patients during COVID-19., Methods and Results: In this multicentre, observational, cohort study over a 100-day period during the COVID-19 pandemic in the USA, we assessed ventricular arrhythmias in ICD patients from 20 centres in 13 states, via remote monitoring. Comparison was via a 100-day control period (late 2019) and seasonal control period (early 2019). The primary outcome was the impact of COVID-19 on ventricular arrhythmia burden. The secondary outcome was correlation with COVID-19 incidence. During the COVID-19 period, 5963 ICD patients underwent remote monitoring, with 16 942 episodes of treated ventricular arrhythmias (2.8 events per 100 patient-days). Ventricular arrhythmia burden progressively declined during COVID-19 (P < 0.001). The proportion of patients with ventricular arrhythmias amongst the high COVID-19 incidence states was significantly reduced compared with those in low incidence states [odds ratio 0.61, 95% confidence interval (CI) 0.54-0.69, P < 0.001]. Comparing patients remotely monitored during both COVID-19 and control periods (n = 2458), significantly fewer ventricular arrhythmias occurred during COVID-19 [incident rate ratio (IRR) 0.68, 95% CI 0.58-0.79, P < 0.001]. This difference persisted when comparing the 1719 patients monitored during both the COVID-19 and seasonal control periods (IRR 0.69, 95% CI 0.56-0.85, P < 0.001)., Conclusions: During COVID-19, there was a 32% reduction in ventricular arrhythmias needing device therapies, coinciding with measures of social isolation. There was a 39% reduction in the proportion of patients with ventricular arrhythmias in states with higher COVID-19 incidence. These findings highlight the potential role of real-life stressors in ventricular arrhythmia burden in individuals with ICDs., Trial Registration: Australian New Zealand Clinical Trial Registry; URL: https://www.anzctr.org.au/; Unique Identifier: ACTRN12620000641998., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: Atrial fibrillation (AF) is more common in athletes and may be associated with adverse left atrial (LA) remodelling. We compared LA structure and function in athletes and non-athletes with and without AF., Methods and Results: Individuals (144) were recruited from four groups (each n = 36): (i) endurance athletes with paroxysmal AF, (ii) endurance athletes without AF, (iii) non-athletes with paroxysmal AF, and (iv) non-athletic healthy controls. Detailed echocardiograms were performed. Athletes had 35% larger LA volumes and 51% larger left ventricular (LV) volumes vs. non-athletes. Non-athletes with AF had increased LA size compared with controls. LA/LV volume ratios were similar in both athlete groups and non-athlete controls, but LA volumes were differentially increased in non-athletes with AF. Diastolic function was impaired in non-athletes with AF vs. non-athletes without, while athletes with and without AF had normal diastolic function. Compared with non-AF athletes, athletes with AF had increased LA minimum volumes (22.6 ± 5.6 vs. 19.2 ± 6.7 mL/m2, P = 0.033), with reduced LA emptying fraction (0.49 ± 0.06 vs. 0.55 ± 0.12, P = 0.02), and LA expansion index (1.0 ± 0.3 vs. 1.2 ± 0.5, P = 0.03). LA reservoir and contractile strain were decreased in athletes and similar to non-athletes with AF., Conclusion: Functional associations differed between athletes and non-athletes with AF, suggesting different pathophysiological mechanisms. Diastolic dysfunction and reduced strain defined non-athletes with AF. Athletes had low atrial strain and those with AF had enlarged LA volumes and reduced atrial emptying, but preserved LV diastolic parameters. Thus, AF in athletes may be triggered by an atrial myopathy from exercise-induced haemodynamic stretch consequent to increased cardiac output., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: Physical activity reduces cardiovascular disease burden and mortality, although its relationship with cardiac arrhythmias is less certain. The aim of this study was to assess the association between self-reported physical activity and atrial fibrillation (AF), ventricular arrhythmias and bradyarrhythmias, across the UK Biobank cohort., Methods and Results: We included 402 406 individuals (52.5% female), aged 40-69 years, with over 2.8 million person-years of follow-up who underwent self-reported physical activity assessment computed in metabolic equivalent-minutes per week (MET-min/wk) at baseline, detailed physical assessment and medical history evaluation. Arrhythmia episodes were diagnosed through hospital admissions and death reports. Incident AF risk was lower amongst physically active participants, with a more pronounced reduction amongst female participants [hazard ratio (HR) for 1500 vs. 0 MET-min/wk: 0.85, 95% confidence interval (CI) 0.74-0.98] than males (HR for 1500 vs. 0 MET-min/wk: 0.90, 95% CI 0.82-1.0). Similarly, we observed a significantly lower risk of ventricular arrhythmias amongst physically active participants (HR for 1500 MET-min/wk 0.78, 95% CI 0.64-0.96) that remained relatively stable over a broad range of physical activity levels between 0 and 2500 MET-min/wk. A lower AF risk amongst female participants who engaged in moderate levels of vigorous physical activity was observed (up to 2500 MET-min/wk). Vigorous physical activity was also associated with reduced ventricular arrhythmia risk. Total or vigorous physical activity was not associated with bradyarrhythmias., Conclusion: The risk of AF and ventricular arrhythmias is lower amongst physically active individuals. These findings provide observational support that physical activity is associated with reduced risk of atrial and ventricular arrhythmias., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: There is growing evidence that magnetic resonance imaging (MRI) scanning in patients with non-conditional cardiac implantable electronic devices (CIEDs) can be performed safely. Here, we aim to assess the safety of MRI in patients with non-conditional CIEDs., Methods and Results: English scientific literature was searched using PubMed/Embase/CINAHL with keywords of 'magnetic resonance imaging', 'pacemaker', 'implantable defibrillator', and 'cardiac resynchronization therapy'. Studies assessing outcomes of adverse events or significant changes in CIED parameters after MRI scanning in patients with non-conditional CIEDs were included. References were excluded if the MRI conditionality of the CIEDs was undisclosed; number of patients enrolled was <10; or studies were case reports/series. About 35 cohort studies with a total of 5625 patients and 7196 MRI scans (0.5-3 T) in non-conditional CIEDs were included. The overall incidence of lead failure, electrical reset, arrhythmia, inappropriate pacing and symptoms related to pocket heating, or torque ranged between 0% and 1.43%. Increase in pacing lead threshold >0.5 V and impedance >50Ω was seen in 1.1% [95% confidence interval (CI) 0.7-1.8%] and 4.8% (95% CI 3.3-6.4%) respectively. The incidence of reduction in P- and R-wave sensing by >50% was 1.5% (95% CI 0.6-2.9%) and 0.4% (95% CI 0.06-1.1%), respectively. Battery voltage reduction of >0.04 V was reported in 2.2% (95% CI 0.2-6.1%)., Conclusion: This meta-analysis affirms the safety of MR imaging in non-conditional CIEDs with no death or implantable cardioverter-defibrillator shocks and extremely low incidence of lead or device-related complications., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aims: To investigate the composition of nocturnal hypoxaemic burden and its prognostic value for cardiovascular (CV) mortality in community-dwelling older men., Methods and Results: We analysed overnight oximetry data from polysomnograms obtained in 2840 men from the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study (ClinicalTrials.gov Identifier: NCT00070681) to determine the number of acute episodic desaturations per hour (oxygen desaturation index, ODI) and time spent below 90% oxygen saturation (T90) attributed to acute desaturations (T90desaturation) and to non-specific drifts in oxygen saturation (T90non-specific), respectively, and their relationship with CV mortality. After 8.8 ± 2.7 years follow-up, 185 men (6.5%) died from CV disease. T90 [hazard ratio (HR) 1.21, P < 0.001], but not ODI (HR 1.13, P = 0.06), was significantly associated with CV death in univariate analysis. T90 remained significant when adjusting for potential confounders (HR 1.16, P = 0.004). Men with T90 > 12 min were at an elevated risk of CV mortality (HR 1.59; P = 0.006). Approximately 20.7 (5.7-48.5) percent of the variation in T90 could be attributed to non-specific drifts in oxygen saturation. T90desaturation and T90non-specific were individually associated with CV death but combining both variables did not improve the prediction., Conclusion: In community-dwelling older men, T90 is an independent predictor of CV mortality. T90 is not only a consequence of frank desaturations, but also reflects non-specific drifts in oxygen saturation, both contributing towards the association with CV death. Whether T90 can be used as a risk marker in the clinical setting and whether its reduction may constitute a treatment target warrants further study., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Aims: An integrated chronic care programme in terms of a specialized outpatient clinic for patients with atrial fibrillation (AF), has demonstrated improved clinical outcomes. The aim of this study is to assess all-cause mortality in patients in whom AF management was delivered through a specialized outpatient clinic offering an integrated chronic care programme., Methods and Results: Post hoc analysis of a Prospective Randomized Open Blinded Endpoint Clinical trial to assess all-cause mortality in AF patients. The study included 712 patients with newly diagnosed AF, who were referred for AF management to the outpatient service of a University hospital. In the specialized outpatient clinic (AF-Clinic), comprehensive, multidisciplinary, and patient-centred AF care was provided, i.e. nurse-driven, physician supervised AF treatment guided by software based on the latest guidelines. The control group received usual care by a cardiologist in the regular outpatient setting.After a mean follow-up of 22 months, all-cause mortality amounted 3.7% (13 patients) in the AF-Clinic arm and 8.1% (29 patients) in usual care [hazard ratio (HR) 0.44, 95% confidence interval (CI) 0.23-0.85; P = 0.014]. This included cardiovascular mortality in 4 AF-Clinic patients (1.1%) and 14 patients (3.9%) in usual care (HR 0.28; 95% CI 0.09-0.85; P = 0.025). Further, 9 patients (2.5%) died in the AF-Clinic arm due to a non-cardiovascular reason and 15 patients (4.2%) in the usual care arm (HR 0.59; 95% CI 0.26-1.34; P = 0.206)., Conclusion: An integrated specialized AF-Clinic reduces all-cause mortality compared with usual care. These findings provide compelling evidence that an integrated approach should be widely implemented in AF management., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Asymptomatic arrhythmias are frequently encountered in clinical practice. Although studies specifically dedicated to these asymptomatic arrhythmias are lacking, many arrhythmias still require proper diagnostic and prognostic evaluation and treatment to avoid severe consequences, such as stroke or systemic emboli, heart failure, or sudden cardiac death. The present document reviews the evidence, where available, and attempts to reach a consensus, where evidence is insufficient or conflicting., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Aims: Atrio-oesophageal fistula (AOF) is a potentially lethal complication of atrial fibrillation (AF) ablation. Many studies have evaluated the presence and prevention of endoscopically-detected oesophageal lesions (EDOL) as a proxy measure for risk of AOF. This systematic review and meta-analysis sought to determine the prevalence of EDOL and effectiveness of general preventive measures during AF ablation., Methods and Results: We searched electronic databases for studies reporting prevalence or prevention of EDOL post-AF ablation. Pooled prevalence were reported with 95% confidence intervals (CI) while studies evaluating preventive measures including oesophageal temperature monitoring (OTM), esophageal manipulation and type of anaesthesia were analyzed descriptively or by random-effects modeling. Twenty-five studies were included in the analysis. Any and ulcerated EDOL pooled prevalence was 11% (95%CI, 6-15%) and 5% (95%CI, 3-7%), respectively. In six studies, there was no difference in EDOL with or without OTM (pooled OR 1.65, 95%CI, 0.22-12.55). There was no difference using a multi-sensor versus single-sensor OTM (one study) nor when using a deflectable probe (two studies). Oesophageal displacement was associated with significant instrumentation injury in one study. Two studies evaluating Oesophageal cooling showed conflicting results. General anaesthesia was associated with more EDOL than conscious sedation in two studies., Conclusion: The pooled prevalence of any and ulcerated EDOL post-ablation was 11% and 5%, but varied between studies. Techniques such as OTM and oesophageal displacement or cooling have not conclusively demonstrated a reduction in EDEL, while general anaesthesia may be associated with higher EDOL risk. Further randomized data are critically needed to validate and develop measures to prevent EDOL and AOF.

Objectives: Atrial fibrillation is treated surgically by creating conduction block lesions. Radiofrequency (RF) lesions have reduced efficacy compared to 'cut-and-sew'. Catheter ablation studies demonstrate a relationship between lesion depth and contact force. We hypothesized that contact force and lesion depth are dependent on design of the bipolar surgical RF clamps., Methods: Hinged and parallel jaw style RF clamps were studied. Muscle samples were clamped with pressure-sensitive film at increasing tissue thicknesses. Films were analysed determining clamp pressure profiles. A sheep model was utilized for ablation testing using each clamp style until the device indicated transmurality. Separate muscle areas had 1, 2 or 3 burns applied. The muscle was excised, sectioned every 1 cm and stained for lesion depth and fat thickness analysis., Results: Pressure profiling comparing the proximal and distal segments of each clamp style demonstrated only one statistically significant difference in the parallel clamp; the hinged clamp had statistically significant differences (P ≤ 0.03) for all tissue thicknesses. There was no evidence for differences in the proximal lesion depth of both clamps (P = 0.13) but deeper distally in the parallel clamp (10.17 mm vs 8.02 mm, P = 0.003). The logistic regression analysis demonstrated increased odds of transmurality with parallel clamps at 1, 2 or 3 burns (P = 0.03, P = 0.003 and P = 0.002). Every 1 mm increase in overlying fat decreased likelihood of transmurality by 11% (P < 0.05)., Conclusions: The parallel and hinged clamps have different pressure profiles with higher likelihood of transmurality using the parallel clamp. Fat reduces the ability of RF to deliver a transmural lesion. These findings have implications for optimal surgical RF ablation technique.

Aims: Antiarrhythmic drugs (AADs) for the treatment of atrial fibrillation (AF) are associated with limited efficacy and adverse effects. Inhibition of the atrial current IKur, absent from the ventricle, is expected to be antiarrhythmic, without adverse cardiac effects, particularly ventricular pro-arrhythmic effects., Methods and Results: A randomized clinical trial in symptomatic paroxysmal AF patients being considered for ablation. The primary endpoint was AF burden (AFB) as measured by insertable continuous monitoring (ICM) devices. Screened patients had an ICM implanted and were included if AFB was between 1% and 70% after 4 weeks of recording. They were randomly allocated to 4-week treatment of a selective IKur inhibitor S66913 (5 mg, 25 mg, or 100 mg orally per day) or placebo. The study was to enroll 160 patients. The study was terminated prematurely, due to non-study related preclinical safety concerns, after 58 patients had been enrolled. The median AFB ranged from 4.3% to 10.3% at baseline in the four treatment groups. S66913 had no significant effect on AFB or on AFB plus atrial tachycardia (AT) burden, at any dosage; nor on any secondary endpoints including the number and duration of AT or AF episodes, and symptoms. The drug was well tolerated with no safety concern during the treatment or the extended clinical follow-up., Conclusions: DIAGRAF-IKUR was the first study to show that using ICM to assess the effect of an AAD is feasible. The selective IKur inhibitor S66913 was safe but had no clinically meaningful effect at the time of early termination of the study.

Aims: Atrial fibrillation (AF) is a progressive disease. Obesity is associated with progression of AF. This study evaluates the impact of weight and risk factor management (RFM) on progression of the AF., Methods and Results: As described in the Long-Term Effect of Goal-Directed Weight Management in an Atrial Fibrillation Cohort: A Long-Term Follow-Up (LEGACY) Study, of 1415 consecutive AF patients, 825 had body mass index ≥ 27 kg/m2 and were offered weight and RFM. After exclusion, 355 were included for analysis. Weight loss was categorized as: Group 1 (<3%), Group 2 (3-9%), and Group 3 (≥10%). Change in AF type was determined by clinical review and 7-day Holter yearly. Atrial fibrillation type was categorized as per the Heart Rhythm Society consensus. There were no differences in baseline characteristic or follow-up duration between groups (P = NS). In Group 1, 41% progressed from paroxysmal to persistent and 26% from persistent to paroxysmal or no AF. In Group 2, 32% progressed from paroxysmal to persistent and 49% reversed from persistent to paroxysmal or no AF. In Group 3, 3% progressed to persistent and 88% reversed from persistent to paroxysmal or no AF (P < 0.001). Increased weight loss was significantly associated with greater AF freedom: 45 (39%) in Group 1, 69 (67%) in Group 2, and 116 (86%) in Group 3 (P ≤ 0.001)., Conclusion: Obesity is associated with progression of the AF disease. This study demonstrates the dynamic relationship between weight/risk factors and AF. Weight-loss management and RFM reverses the type and natural progression of AF.

Aims: Intermittent change in p-wave discernibility during periods of ectopy and sinus arrhythmia is a cause of inappropriate atrial fibrillation (AF) detection in insertable cardiac monitors (ICM). To address this, we developed and validated an enhanced AF detection algorithm., Methods and Results: Atrial fibrillation detection in Reveal LINQ ICM uses patterns of incoherence in RR intervals and absence of P-wave evidence over a 2-min period. The enhanced algorithm includes P-wave evidence during RR irregularity as evidence of sinus arrhythmia or ectopy to adaptively optimize sensitivity for AF detection. The algorithm was developed and validated using Holter data from the XPECT and LINQ Usability studies which collected surface electrocardiogram (ECG) and continuous ICM ECG over a 24-48 h period. The algorithm detections were compared with Holter annotations, performed by multiple reviewers, to compute episode and duration detection performance. The validation dataset comprised of 3187 h of valid Holter and LINQ recordings from 138 patients, with true AF in 37 patients yielding 108 true AF episodes ≥2-min and 449 h of AF. The enhanced algorithm reduced inappropriately detected episodes by 49% and duration by 66% with <1% loss in true episodes or duration. The algorithm correctly identified 98.9% of total AF duration and 99.8% of total sinus or non-AF rhythm duration. The algorithm detected 97.2% (99.7% per-patient average) of all AF episodes ≥2-min, and 84.9% (95.3% per-patient average) of detected episodes involved AF., Conclusion: An enhancement that adapts sensitivity for AF detection reduced inappropriately detected episodes and duration with minimal reduction in sensitivity.

Aims: Real-time contact force (CF)-sensing radiofrequency ablation catheter for treatment of paroxysmal atrial fibrillation (PAF) allows optimization of electrode-tissue contact, which correlates with long-term success. This prospective, multicentre observational registry assessed the real-world clinical effectiveness of a CF-sensing catheter for ablation of drug-refractory PAF., Methods and Results: Patients were followed-up at 3, 6, and 12 months after ablation. Outcome measures included isolation of targeted pulmonary veins (PVs) confirmed by entrance block (acute success), patient-reported freedom from symptomatic atrial fibrillation (AF) at 12 months (long-term effectiveness), Atrial Fibrillation Effect on Quality-of-life scores at 6 and 12 months, and incidence of predefined procedural complications. The registry enrolled 261 PAF patients (mean age 58.8 ± 11.3 years; 70.7% men; 91.7% Caucasian). Acute PV isolation was reported in 98.8% of patients [95% confidence interval (CI): 96.4-99.7%], and 12-month success for freedom from symptomatic AF was 75.7% (95% CI: 69.7-80.7%). Average CF for the evaluable cohort was 16.4 ± 3.9 g. There was a significant correlation between long-term effectiveness and stability of CF use [percentage of time CF was within investigator-selected working range; odds ratio (95% Wald CI), 1.0 (1.00-1.1); P = 0.030]. Average CF did not correlate with 12-month success. Clinically meaningful quality of life (QoL) improvements were observed at 6 and 12 months. Primary adverse events occurred in 2.7% patients., Conclusion: This observational registry showed that PAF ablation with a CF-sensing catheter had high acute success rates, favourable 12-month outcomes, and a good safety profile. Patients' QoL improved significantly. Long-term effectiveness significantly correlated with stable CF with adequate catheter-tissue contact (NCT01677052).

Aims: Several techniques have been utilized for the ablation of persistent (P) and long-standing persistent (LsP) atrial fibrillation (AF); however, the best approach of substrate ablation remains poorly defined. This study aims to examine the impact of ablation approach on outcomes associated with P or LsP AF ablation by conducting a meta-analysis and regression on contemporary literature., Methods and Results: A systematic literature review was conducted up to 29 July 2015 for scientific literature reporting on outcomes associated with P or LsP AF ablation. One hundred and thirteen studies reported outcomes in a total of 18 657 patients undergoing various ablation approaches for the treatment of P-LsP AF between 2001 and 2015. The point efficacy estimate of a single-AF ablation procedure without the use of anti-arrhythmic drugs was 43% (95% CI; 39-47%). Multiple procedures and/or the use of anti-arrhythmic drugs increase success to 69% (95% CI; 66-71%). Meta-regression revealed that ablation technique (P < 0.001) and left atrial size (P = 0.02) were predictive of single procedure, drug-free success. The addition of extra-pulmonary substrate approaches was associated with declining efficacy when compared to a pulmonary vein ablation alone., Conclusion: The efficacy of a single-AF ablation procedure for P or LsP AF is 43%; however, can be increased to 69% with the use of multiple procedures and/or anti-arrhythmic drugs. Current literature supports the finding that pulmonary vein antrum ablation/isolation is at least equivalently efficacious to other contemporary P-LsP ablation strategies.