Reduction In Atrial Fibrillation Burden Research Articles

Combined Radiofrequency Ablation and Left Atrial Appendage Closure in Atrial Fibrillation and Systolic Heart Failure.

Managing patients with atrial fibrillation (AF) and comorbid heart failure (HF) with reduced (HFrEF) or mildly reduced ejection fraction (HFmrEF) is of clinical importance but a great challenge. This study aimed to evaluate the clinical benefit of the combined radiofrequency catheter ablation (RFCA) and left atrial appendage closure (LAAC) procedure in AF patients complicated with systolic HF. AF patients with HFrEF or HFmrEF who underwent the combined RFCA and LAAC procedure were prospectively enrolled in the LAACablation registry. The procedural complications and long-term outcomes were evaluated. Another cohort of AF patients with systolic HF who did not undergo either RFCA or LAAC were used for prognosis comparison. Among 802 AF patients who underwent the combined procedure, 65 patients were comorbid with systolic HF (25 with HFrEF and 40 with HFmrEF). The overall procedural complication rate was 9.2%, which was mainly attributed to acute decompensated HF (6.2%). Accompanied with markedly reduced AF burden (from median [25th, 75th percentile]: 100 [100, 100] to 0 [0, 1.2]%, p < 0.001), upward trajectories of cardiac function were observed in 51 (78.4%) patients, showing improvement in New York Heart Classification (p < 0.01), natriuretic peptide levels (from 1492 [809, 3259] to 413 [163, 880] pg/mL, p < 0.001) and left ventricular EF (from 42.6 ± 5.3 to 53.8 ± 8.2%, p < 0.001). During the 27-month follow-up period, death, thromboembolism, major bleeding, and HF rehospitalization were observed in three, one, one, and four patients, respectively. The observed event rates showed a significant reduction compared with the non-procedure AF-HF cohort (n = 138; for composite endpoint: hazard ratio: 2.509, 95% confidence interval: 1.415-4.449, p = 0.002) and with the respective rates predicted by risk scores. Combining RFCA and LAAC achieves acceptable safety and credible long-term efficacy in AF patients with systolic HF. Further randomized studies are warranted in a larger patient cohort.

Catheter ablation of atrial fibrillation in elderly and very elderly patients: safety, outcomes, and quality of life.

Atrial fibrillation (AF) risk increases with age. We aim to assess the efficacy and safety of catheter ablation in the older population. All patients undergoing AF ablation (2013-2021) at our institution were enrolled in a prospectively maintained registry. The primary endpoint was AF recurrence. Patients were divided into 3 groups: non-elderly (< 65 years), elderly (65-75 years), and very elderly (> 75 years). Patient surveys at baseline and during follow-up were used to calculatequality of life (QoL)metrics: the AF severity score as well as the AF burden. A total of 7020 patients were included (42% non-elderly, 42% elderly, and 16% very elderly). Periprocedural major complications were low (< 1.5%) and similar in all groups besides pericardial effusion which was more frequent with older age and similar between the elderly and very elderly. At 3 years, AF recurrence for persistent AF (PersAF) was highest in the very elderly group (48%), followed by the elderly group (42%), and was the lowest in the non-elderly group (36%). In paroxysmal AF (PAF), there was no difference in AF recurrence between the elderly and non-elderly, while the very elderly remained associated with a significantly increased risk. Multivariable Cox analysis confirmed these findings (PersAF; elderly: HR = 1.23, P = 0.003; very elderly: HR = 1.44, P < 0.001) (PAF; elderly: HR = 1.04, P = 0.62; very elderly: HR = 1.30, P = 0.01). Catheter ablation resulted in a significant improvement in quality of life, irrespective of age group. Catheter ablation in elderly and very elderly patients is safe, efficacious, and associated with QoL benefits. Overall, major complications were minimal and did not differ significantly between age groups, with the exception of pericardial effusions which were higher in the elderly and very elderly compared to non-elderly adults. Very elderly patients had a higher rate of AF recurrence when compared with elderly or non-elderly patients. Nevertheless, ablation resulted in a remarkable improvement in QoL and a reduction of AF burden and AF symptoms with a similar magnitude, irrespective of age.

Combined effects of high atrial septal pacing and reactive atrial antitachycardia pacing for reducing atrial fibrillation in sick sinus syndrome.

It is unknown whether atrial fibrillation (AF) burden varies by pacing site in patients with reactive atrial antitachycardia pacing (rATP). We aimed to compare AF burden in patients with high atrial septal pacing (HASp) via delivery catheter and right atrial appendage pacing (RAAp) in patients with sick sinus syndrome (SSS). We retrospectively identified 109 patients with a history of paroxysmal AF and SSS who had received dual-chamber pacemaker implantation between January 2017 and December 2019, of whom 39 and 70 patients had HASp and RAAp, respectively. rATP was initiated after a 1-month post-implantation run-in period. Patients with HASp had a significantly shorter P-wave duration during atrial pacing than those with RAAp (99.3 ± 10.4 vs. 116.0 ± 14.3 ms, p < .001). During the 3-year follow-up period, the incidence of an AF lasting longer than 1 or 7 days was significantly lower (hazard ratio [HR], 0.45; p = .016; HR, 0.24; p = .004) than in those with RAAp. The median time of AF/AT per day in the follow-up periods was significantly shorter in the HASp group than in the RAAp group (10 vs. 18 min/day, p = .018). Atrial lead division did not occur in the HASp group during the follow-up period. HASp via delivery catheter is as safe as RAAp, and HASp combined with rATP is effective for reducing AF burden in patients with SSS and paroxysmal AF.

Impact of catheter ablation on atrial fibrillation burden and symptoms in patients with hypertrophic cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial Fibrillation (AF) is more common in patients with hypertrophic cardiomyopathy (HCM) and is often very symptomatic in this cohort. The impact of catheter ablation (CA) in this context is controversial with low success rates using the guideline mandated end-point of freedom from arrhythmia. Purpose To determine whether CA of AF in patients with HCM would be associated with a significant reduction in AF burden and symptoms. Methods Patients diagnosed with HCM undergoing CA of AF between February 2017 and June 2021 were identified from a prospective, single-centre registry. Patients with CIED in situ were selected. Patients were followed up for objective evaluation of symptom severity. Interval device interrogation and remote CIED monitoring was used to determine first AF/AT recurrence and percentage AF/AT burden on continuous rhythm monitoring 12-months before and after CA. Results Of 257 HCM patients undergoing CA of AF, 33 had CIEDs and were followed up for 32±15 months. The mean age was 56.4±10.2 years and 22 (67%) were male. The maximal wall thickness on echocardiography was 1.7±0.3cm and LA diameter was 4.8±0.9. The left ventricular ejection fraction was 50±15%. 17 (52%) patients had paroxysmal AF and 16 (48%) had persistent AF of which 6 (18%) were longstanding persistent AF. Mean AF burden prior to CA was 36.9±26.5% and 24 (73%) reported EHRA III-IV symptom severity. AF recurred in 27 (82%) patients with a median time to first recurrence of 8 (3-17) months. AF burden significantly reduced after index AF CA (27% (7,59) to 2% (0, 41)) (Z=-2.2, p= 0.03)) and reduced further when allowing for repeat procedures in 10 (30%) patients to 0% (0-30%). This represented a &amp;gt;50% relative reduction in 22 (67%) patients and &amp;gt;95% relative reduction in 16 (48%) patients. This correlated with a reduction in symptom score with 20 (60.6%) patients reporting a change of ≥1 EHRA class, and 20 (60.6%) patients reporting EHRA class I-IIa status at 12 months. A positive relationship was seen on regression analysis, with a 16.4% absolute reduction in AF burden associated with a reduction of one EHRA class. (R2= 0.206, F=7.5, p=0.01). Amongst the 24 (72%) patients who had an AF/AT recurrence after the final procedure who would conventionally be called failures by guideline definitions, 11 (45.8%) patients improved by ≥ 1 EHRA class and 11 (45.8%) were class I-IIa. Conclusion Although AF recurrence is common after CA in HCM patients, there is a significant reduction in AF burden and symptoms in a majority of patients. A more comprehensive evaluation of AF burden, symptoms, quality of life and impact on hard end-points is needed to determine the utility of CA in this context.

Electrocardiographic markers of subclinical atrial fibrillation detected by implantable loop recorder

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The LOOP Study was funded by Innovation Fund Denmark [grant number 12-1352259], The Research Foundation for the Capital Region of Denmark, The Danish Heart Foundation [grant number 11-04-R83-A3363-22625], Aalborg University Talent Management Program, Arvid Nilssons Fond, Skibsreder Per Henriksen, R og Hustrus Fond, the European Union’s Horizon 2020 program [grant number 847770], Læge Sophus Carl Emil Friis og hustru Olga Doris Friis’ Legat, and an unrestricted grant from Medtronic. Background Atrial fibrillation (AF) is a well-known and treatable risk factor for stroke, which has sparked a substantial interest in AF screening. However, further insights into subclinical AF development are warranted to inform strategies of screening and subsequent clinical management upon AF detection. Purpose This study sought to identify 12-lead electrocardiogram (ECG) parameters associated with the onset, burden and progression of subclinical AF detected by long-term continuous monitoring. Methods We included AF-naïve individuals aged 70-90 years with ≥1 additional stroke risk factors (hypertension, diabetes, heart failure, or prior stroke) who underwent implantable loop recorder (ILR) monitoring in the LOOP Study. Using data from daily ILR recordings and computerized analysis of baseline ECG, we studied empirically selected ECG parameters for AF detection (≥6 minutes), cumulative AF burden, long-lasting AF (≥24 hours), and AF progression. Results Of 1370 individuals included, 419 (30.6%) developed AF during follow-up, with a mean cumulative AF burden of 1.5% [95% confidence interval (CI): 1.2-1.8%]. Several P-wave-related and ventricular ECG parameters were associated with new-onset AF as well as with cumulative AF burden in AF patients. P-wave duration (PWD), P-wave terminal force in lead V1, and interatrial block (IAB) further demonstrated significant associations with the risk of AF episode ≥24 hours. Among AF patients, we observed an overall reduction in cumulative AF burden over time (incidence rate ratio 0.70 [95% CI: 0.51-0.96]), whereas IAB was related to an increased risk of progression to AF episodes ≥24 hours (hazard ratio 1.86 [95% CI: 1.02-3.39]). Further spline analysis revealed longer PWD to also be associated with this progression in AF duration. Conclusions We identified several ECG parameters associated with new-onset AF detected by ILR. Especially PWD and IAB were robustly related to the onset and the burden of subclinical AF as well as progression over time.

Association of clinical characteristics and biomarkers with recurrent atrial fibrillation after hybrid ablation

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Atrial fibrillation ablation research at our institution was supported by an unrestricted grant from AtriCure. Background Hybrid ablation is an alternative treatment for both persisting and therapy-resistant, symptomatic atrial fibrillation (AF), combining the strengths of endocardial catheter and epicardial surgical ablation. Although results exhibit lower rates of recurrence and higher reduction of AF burden, there is a considerable risk of procedure-related complications. Therefore, the identification of patient groups who benefit most of this procedure can help in pre-procedural selection and tailoring of optimal therapy post-ablation. Purpose This study aimed to identify clinical factors and blood biomarkers associated with recurrence of AF within 1 year post-ablation. Methods A total of 96 consecutive patients undergoing hybrid ablation between January 2015 and December 2018 in a tertiary care center were enrolled. Blood samples were collected pre-ablation. Seven biomarkers [Bone Morphogenetic Protein 10 (BMP10), angiopoietin-2 (ANG2), Dickkopf WNT Signaling Pathway Inhibitor 3 (DKK3), Endothelial Cell Specific Molecule 1 (ESM1), Fibroblast Growth Factor 23 (FGF23), Insulin Like Growth Factor Binding Protein 7 (IGFBP7) and total N-terminal pro b-type natriuretic peptide (NT-proBNP)] were assayed at Roche Diagnostics based on their possible association with recurrence of AF. Clinical follow-up visits combined with 12-lead ECG and 24-hour Holter monitoring were scheduled at 3, 6 and 12 months post-procedure. Cox proportional hazards regression models were used to study the association with recurrence of AF. Results Out of the 96 patients (mean age 58±8 years; 18% women), 17 (17.7%) developed recurrence of AF within 1 year post-ablation. Median time to diagnosis was 191 days (range: 92-344). Comparisons between patients with and without recurrence of AF are depicted in Table 1. Multivariable Cox proportional hazard regression, adjusted for sex, showed that older age (HR 1.104, 95% CI 1.003-1.215, p=0.043), type of AF (HR 0.322, 95% CI 0.117-0.886, p=0.028), a history of peripheral vascular disease (HR 13.84, 95% CI 3.13-61.14, p&amp;lt;0.001) and recurrence in the blanking period (HR 14.25, 95% CI 3.99-50.85, p&amp;lt;0.001) were associated with recurrence of AF within 1 year post-ablation, but no blood biomarkers (Figure 1). Conclusion In AF patients undergoing extensive ablation, older age, type of AF, a history of peripheral vascular disease and recurrence in the blanking period were determinants of AF recurrence within 1 year post-ablation.

PO-02-203 IMPACT OF MITRACLIP IMPLANTATION ON THE BURDEN OF ATRIAL FIBRILLATION

Patients presenting for valve repair for mitral regurgitation (MR) have a 30-40% prevalence of atrial fibrillation (AF). AF and MR share an intricate bidirectional relationship. With the increasing use of MitraClip in contemporary practice, data on its impact on AF burden remains lacking. To study the impact of MitraClip implantation on AF burden using implanted device interrogation data. We performed a single center, retrospective analysis of all patients undergoing MitraClip implantation between, 4/2014 and 3/2022 (n=289). Of these, 60 patients (36%; 33 pacemakers, 27 defibrillators) had pre-existing implanted devices. Amongst these, 15 patients had interrogation data available within 6 months prior, and 12 months after MitraClip implantation - they were included for final analysis. Wilcoxon sum rank test was performed for comparison of variables. A total of 15 patients were included in the final analysis (mean age 76 ±12), with a male predominance (66%) and mean LVEF of 35%. Pre-existing AF was reported in 73% of patients with an AF burden (mean-IQR) of 39.9±48%, pre-MitraClip. A substantial, halving of AF burden to 16.2±34% was observed post-MitraClip (p=0.1). A similar decline in the prevalence of persistent AF from 40% to 20% was noted post-MitraClip. MitraClip implantation is associated with a substantial reduction in AF burden as well as rates of persistent AF. Larger studies are required to further analyze this association.

BS-452758-4 COMBINED GENE THERAPY APPROACH TARGETS PARASYMPATHETIC SIGNALING AND OXIDATIVE STRESS TO ATTENUATE PERSISTENT ATRIAL FIBRILLATION DEVELOPMENT IN A CANINE MODEL

Atrial fibrillation (AF) is the most common arrhythmia, a major risk factor for stroke and is associated with substantial morbidity and mortality. Unfortunately, current pharmacological and interventional treatment approaches are suboptimal. Parasympathetic nervous system (PNS) activity upregulation and oxidative stress (OS), mainly generated by NADPH oxidase 2 (NOX2), have been shown as key players in AF induction and maintenance. A deeper understanding of these molecular mechanisms underlying AF and their interplay will be instrumental to the development of new, mechanism-targeted therapies for AF. To evaluate whether combined gene therapy can inhibit parasympathetic signaling (Gαi and Gαo - GiGo) and reactive oxygen species generation and attenuate AF development and maintenance in a large animal chronic AF model. Combination of plasmids expressing NOX2 (main source of OS in atrial cardiomyocytes) short hairpin RNA and GiGo inhibitory peptides (GiGo_ct) was injected in the canine (n=4) atria followed by electroporation to facilitate gene delivery. Rapid atrial pacing (RAP) was performed for up to 8 weeks. Residual AF was evaluated at terminal EP study. Plasmids expression was evaluated with polymerase chain reaction (PCR). Controls developed persistent AF (≥8 hours) after a median of 14 days. Combined (NOX2+GiGo) gene therapy attenuated development of persistent AF and significantly reduced AF burden by 32% (Panel A). AF at the terminal experiment displayed increased organization in gene therapy animals (panel B), with one animal spontaneously converting to sinus rhythm. PCR analysis showed NOX2 downregulation and evidence of GiGo_ct expression upon >2 months since gene injection. Targeting both parasympathetic nerve signaling and OS significantly attenuated AF development, which proves their important mechanistic role. Gene-based, selective parasympathetic signaling inhibition by GiGo_ct and oxidative stress attenuation by NADPH oxidase 2 downregulation prevents initiation and maintenance AF. Future optimization of gene therapy and developing combined approaches to target several mechanisms of AF pathophysiology simultaneously may lead to novel treatments for AF.

Electrocardiographic markers of subclinical atrial fibrillation detected by implantable loop recorder: insights from the LOOP Study.

Insights into subclinical atrial fibrillation (AF) development are warranted to inform the strategies of screening and subsequent clinical management upon AF detection. Hence, this study sought to characterize the onset and progression of subclinical AF with respect to 12-lead electrocardiogram (ECG) parameters. We included AF-naïve individuals aged 70-90 years with additional stroke risk factors who underwent implantable loop recorder (ILR) monitoring in the LOOP Study. Using data from daily ILR recordings and the computerized analysis of baseline ECG, we studied empirically selected ECG parameters for AF detection (≥6 min), cumulative AF burden, long-lasting AF (≥24 h), and AF progression. Of 1370 individuals included, 419 (30.6%) developed AF during follow-up, with a mean cumulative AF burden of 1.5% [95% CI: 1.2-1.8]. Several P-wave-related and ventricular ECG parameters were associated with new-onset AF and with cumulative AF burden in AF patients. P-wave duration (PWD), P-wave terminal force in Lead V1, and interatrial block (IAB) further demonstrated significant associations with long-lasting AF. Among AF patients, we observed an overall reduction in cumulative AF burden over time (IRR 0.70 [95% CI: 0.51-0.96]), whereas IAB was related to an increased risk of progression to AF ≥24 h (HR 1.86 [95% CI: 1.02-3.39]). Further spline analysis also revealed longer PWD to be associated with this progression in AF duration. We identified several ECG parameters associated with new-onset subclinical AF detected by ILR. Especially PWD and IAB were robustly related to the onset and the burden of AF as well as progression over time.

Lifestyle changes in atrial fibrillation management and intervention.

Atrial fibrillation (AF) is one of the most common arrhythmias in adults, and its continued rise in the United States is complicated by the increased incidence and prevalence of several AF risk factors, such as obesity, physical inactivity, hypertension, obstructive sleep apnea, diabetes mellitus, coronary artery disease, and alcohol, tobacco, or caffeine use. Lifestyle and risk factor modification has been proposed as an additional pillar of AF therapy, added to rhythm control, rate control, and anticoagulation, to reduce AF burden and risk. Although emerging evidence largely supports the integration of lifestyle and risk factor management in clinical practice, randomized clinical trials investigating the long-term sustainability and reproducibility of these benefits remain sparse. The purpose of this review is to discuss potentially reversible risk factors on AF, share evidence for the impact on AF by modification of these risk factors, and then provide an overview of the effects of reversing or managing these risk factors on the success of various AF management strategies, such as antithrombotic, rate control, and rhythm control therapies.

Association between atrial fibrillation burden and cognitive function in patients with atrial fibrillation

BackgroundAccumulating evidence has demonstrated an association between clinical atrial fibrillation (AF) and cognitive impairment. This study aimed to further clarify the impact of AF burden on cognitive function based on detailed electrophysiological recordings and standardized assessments of cognitive function. MethodsThis prospective cohort study, conducted at the Cardiac Electrophysiology Clinic of a tertiary center, included patients with non-valvular AF. AF burden was evaluated using 14-day patch-based electrocardiography. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). ResultsEnrolled patients (n = 253) were grouped according to the median AF burden (13.52%). Patients with higher AF burden were significantly older and had larger left atrium size, a worse ejection fraction, and a lower MoCA score than those with lower AF burden. Predictors of MoCA score included age, CHA2DS2-VASc score, AF burden, and Center for Epidemiologic Studies Depression Scale scores. The association between MoCA scores and AF burden remained significant after adjustment for demographic characteristics, underlying diseases, and echocardiographic parameters (standardized beta coefficient: −0.159, 95% confidence interval: −0.020 to −0.004, p = 0.004). ConclusionAF burden is associated with cognitive function in patients with AF. Further studies are required to determine whether reducing AF burden can preserve cognitive function in these patients.

MHealth based patient-centered self-management reduces the burden and episodes of atrial fibrillation

Abstract Background There is a surging development of digital technologies for screening and diagnosis of atrial fibrillation (AF), nonetheless, how these digital technologies impact AF care remains unclear. Objectives The present study aimed to investigate the impact on AF episodes and arrhythmia burden of patient-centered self-management with using smart technologies, incorporating artificial intelligence (AI), wearable and mobile health (mHealth) technology for patient-centred self-management. Methods In this cohort study, we applied AI machine-learning (ML) model predicting AF prior to 4 hours of AF occurrence, while the timely monitoring of AF episodes with photoplethysmography (PPG) technology, and further confirmation of the diagnosis of AF with single-lead ECG, was based on wearable devices. These have been developed in AF screening study (stage 1 pre-mAFA) of Mobile Health technology for improved screening and optimizing integrated care in atrial fibrillation (mAFA II programme), while mHealth supported integrated care of AF was validated to reduce clinical events (stage 2 mAFA II cluster randomized trial). In this observational cohort, the subjects were in 2 groups: (i) subjects with monitored AF but without using mAFA (Group 1); (ii) subjects with monitored AF and using smart devices and mAFA for patient-centered self-management (Group 2). Adult subjects freely downloaded the mAFA AF App, with compatible devices, and were included into the study from across China between October 26, 2018 and Dec 1, 2021. Results From 3499461 subjects involving in AF population screening, there were 5904 subjects in Group 1 (mean age 57 years, SD,15 years; 80.7%, male), while 2667 subjects in Group 2 (51, 15; 89.7% male). The diagnosis of AF episodes was confirmed by single-lead ECG recordings, and decreased among those using mAFA in Group 2 (Confirmed AF: 602 in 1st quarter, 224 in 2nd quarter, 81 in 3rd quarter, 52 in 4th quarter) (all p value for trend&amp;lt;0.001). AF burden was significantly reduced over time (PPG: 26% on 1st month, 19% on 12th month; ECG: 3%, 0.7%, all p&amp;lt;0.001), while the average probability of AF occurrences by AI ML model prediction was decreased among those using mAFA in Group 2 (65%, 57%, p&amp;lt;0.001). The decreasing trend of AF burden over time was not seen in subjects with detected AF without mAFA (Group 1). On multivariate analysis, AI ML model driven mAFA-based upstream risk factor control significantly reduced the changes in AF burden of both Δ 6 month (adjusted OR, 95% CI, 0.51,0.43–0.59) and Δ 12 month (0.39,0.32–0.47, all p&amp;lt;0.001). Conclusion mHealth-AF care increased the adherence of using smart devices for AF detection. The incorporation of smart devices and AI tools into an AF clinical care pathway, effectively reduced AF burden and detected AF episodes, through appropriate rhythm control management and upstream risk factor control. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China

Catheter ablation of symptomatic atrial fibrillation: Sex, ethnicity, and socioeconomic disparities.

Catheter ablation for treatment of atrial fibrillation (AF), AF ablation, is more effective than antiarrhythmic drugs in reducing AF burden, reducing symptoms and increasing health-related quality of life. Although females more often experience AF-related symptoms, and have more severe symptoms, have lower quality of life, and experience more serious adverse effects of antiarrhythmic drugs than males, they are less likely to undergo AF ablation. Potential explanations for the disparity include older age at diagnosis, longer AF duration, a greater number of comorbidities, more extensive atrial fibrosis, and presumed lower success rate and more complications after AF ablation in women. Studies have failed to show sex-related differences in AF recurrence or serious complications following AF ablation but show more nuisance bleeds in women. Ethnic minorities, such as African Americans and Latin Americans, and individuals of low socioeconomic status are also less likely to undergo AF ablation, possibly associated with greater numbers of comorbidities, lack of patient advocacy, healthcare costs, and inadequate insurance coverage. Inclusion of marginalized patient groups in clinical trials of AF treatment and a personalized, patient-centered approach may expand equality in utilization of AF ablation.

Evolving Role of Catheter Ablation for Atrial Fibrillation: Early and Effective Rhythm Control.

Catheter Ablation (CA) is an effective therapeutic option in treating atrial fibrillation (AF). Importantly, recent data show that CA as a rhythm control strategy not only significantly reduces AF burden, but also substantially improves clinical hard endpoints. Since AF is a progressive disease, the time of Diagnosis-to-Intervention appears crucial. Recent evidence shows that earlier rhythm control is associated with a lower risk of adverse cardiovascular outcomes in patients with early AF. Particularly, CA as an initial first line rhythm control strategy is associated with significant reduction of arrhythmia recurrence and rehospitalization in patients with paroxysmal AF. CA is shown to significantly lower the risk of progression from paroxysmal AF to persistent AF. When treating persistent AF, the overall clinical success after ablation remains unsatisfactory, however the ablation outcome in patients with "early" persistent AF appears better than those with "late" persistent AF. "Adjunctive" ablation on top of pulmonary vein isolation (PVI), e.g., ablation of atrial low voltage area, left atrial posterior wall, vein of Marshall, left atrial appendage, etc., may further reduce arrhythmia recurrence in selected patient group. New ablation concepts or new ablation technologies have been developing to optimize therapeutic effects or safety profile and may ultimately improve the clinical outcome.

Abstract 15427: Reduction of Epicardial Fat, Clinical Risk Factors &amp; Symptomatology in Paroxysmal AF Patient With Severe Aortic Stenosis and Metabolic Syndrome via Mobile Cardiometabolic Health &amp; Weight Loss Program

Atrial fibrillation (AF) is dependent on epicardial fat (EpF) accumulation and infiltration. Complementary therapeutic strategies specifically targeting EpF present an opportunity for slowing progression and reversing the course of AF. A 73-year-old man with a history paroxysmal AF (managed by rate control/anticoagulation), severe aortic valve stenosis (AVS, area 1cm 2 , EF 55%), controlled hypertension, diabetes, and obesity (BMI 37.9) completed a 2-month cardiometabolic health program (CHP). The ‘tech plus touch’ CHP, delivered via a smartphone, utilized a comprehensive approach with physiological, nutritional, and behavioral components. Along with patented dietary regimens and nutritional supplementation implemented with personalized treatment algorithms, the CHP included direct daily engagement (messaging &amp; telehealth) with a staff clinician via the HIPAA compliant mobile app. Patient data visible to both the patient and staff clinician was synced automatically via Bluetooth-linked devices. EpF dropped by 25.5% over 9w (transthoracic echo, Fig1). BMI, visceral adiposity, and body fat were significant reduced, while lean body mass (LBM), muscle mass (MM) and intracellular fluid (ICF, a validated surrogate of chronic inflammation) improved (Fig1). Encouragingly, LBM, MM, and ICF improvements were unusual and particularly large in this older, physically inactive patient. Other clinical risk factors improved including diabetes, kidney function and inflammation. The patient reported resolution of chest pain and dyspnea, improved cardiorespiratory fitness, and began aerobic exercise. Our data demonstrate a nonpharmacologic complementary approach produces significant reductions of EpF and modifiable risk factors linked to hypertension, diabetes, and chronic inflammation in an AF patient with AVS and metabolic syndrome. Whether this will lead to a reduction in AF burden or conversion to persistent AF, remains to be determined.

Abstract 14496: NOX2 Inhibition Reverses Atrial Remodeling Caused by Increased Oxidative Stress and Reduces AF in Diet Induced Obese Mice

Introduction: Diet induced obese (DIO) mice display increased inducible atrial fibrillation (AF) and an overall increase in reactive oxygen species (ROS) production. NADPH oxidase 2 (NOX2), a major source of cytosolic ROS production in human atria, has been implicated in AF independent of obesity and is significantly increased in the atria of DIO mice. Although treatment with MitoTEMPO, a mitochondrial specific antioxidant reduced AF burden in DIO mice, the actual role of NOX2 in increasing ROS production and atrial remodeling in the context of obesity-induced AF remains unclear. Hypothesis: To test the hypothesis that increased NOX2 modulates atrial remodeling in obesity-induced AF, we used control mice, DIO and Nox2 -KO mice fed with a 60% HFD for 10 weeks (DIO-KO) and DIO mice treated with a NOX2 blocker, apocynin (DIO-Apocynin). Methods: Trans-esophageal rapid (TE) pacing was used to look at the AF phenotype. Cellular electrophysiology (EP), Western blotting, whole-cell patch clamping were performed to study ion channel remodeling and ROS production. Results: All three DIO mouse groups displayed significantly greater body weight compared to their respective controls (Figure A) After TE pacing, DIO-Apocynin mice displayed 28.26 ± 25.40 s and DIO-KO mice displayed 17.43 ± 31.80 s compared to 167.3 ± 168.9 s in DIO mice (Figure B). NOX2 inhibition reversed obesity-induced ion channel remodeling of potassium channels such as KCNQ1 and KCNE1 encoding for the IKs current and KCNA5 encoding for the IKur current and also reduced mediators of oxidative stress. (Figure C-M) Lastly, voltage clamp in DIO-KO mice showed that NOX2 inhibition reverses obesity-induced IK current increase. (Figure N-O) Conclusions: Thus, these results prove that antioxidant therapy targeting Nox2 abrogated ion channel remodeling and reversed the obesity-induced AF burden. Our findings show the importance of targeting specific antioxidant pathways to manage the AF in patients with obesity.

Abstract 13106: Prevalence, Characteristics, and Outcomes of Atrial Fibrillation Patients Attended by Emergency Medical Services

Introduction: Atrial fibrillation (AF) remains the most common sustained cardiac arrythmia and is a growing burden on healthcare resources, despite improvements in prevention and management. AF is a common cause of hospitalisation, and for acute episodes, patients often contact Emergency Medical Services (EMS) for treatment and transport. However, there is a paucity of data describing the burden of AF presentations on EMS. Aims: To determine prevalence, characteristics, and outcomes of patients presenting with AF attended by EMS using a large population-based sample. Methods: Consecutive EMS attendances for AF in Victoria, Australia from January 2015 to June 2019 were included if patients had a diagnosis of ‘AF’ or ‘arrhythmia’ with AF on electrocardiogram. Data were individually linked to emergency, hospital admission, and mortality records. Results: AF was the reason for emergency ambulance attendance in 23,925 of 2,237,145 cases (1.1%). Median (IQR) age was 76 (66,84) years and 57% were female. Eighty-four percent of patients had a high thromboembolic risk (CHA 2 DS 2 -VASc score ≥2), 73% had a heart rate &gt;100bpm, and &gt;50% were normotensive (mean SBP 133 ± 28mmHg). Forty-four percent of patients received no medical intervention by paramedics and 98% were transported to hospital. From the Emergency Department, 19% of patients were discharged home, 36% went to a short-stay unit, 34% were admitted to a general medical ward, and 7% were admitted to a coronary care unit. Median (IQR) length of stay for those admitted was 1 (1,4) day. Of 5,000 cases reattended for AF during the 4.5 year study period, 22% of reattendances occurred within 30 days and 34% within 6 months of the index event. Overall, 22% died during the study period, 37% of those within 6 months of the index event. Conclusions: EMS utilisation for acute episodes of AF is common and associated with many reattendances. Further studies are required to investigate novel pathways of care to reduce AF burden on healthcare systems.

Effects of different exercise types on quality of life for patients with atrial fibrillation: a systematic review and meta-analysis.

To investigate the effectiveness of exercise and the most effective types of exercise for patients with atrial fibrillation (AF) to improve health-related quality of life (HRQoL) and exercise capacity, and reduce AF burden, AF recurrence and adverse events. Systematic search in PubMed, Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL Plus, and SPORTDiscus for randomized controlled trials (RCTs) and nonrandomized pre-post intervention studies investigating the effect of different types of exercise on AF patients. After exclusion, 12 studies (11 RCTs, 1 prepost) with a total of 670 participants were included. Exercise interventions consisted of aerobic exercise, aerobic interval training (AIT), Qigong, yoga, and exercise-based cardiac rehabilitation (CR). There were significant positive effects of exercise on general health {mean difference [MD] = 6.42 [95% confidence interval (CI): 2.90, 9.93]; P = 0.0003; I2 = 17%} and vitality [MD = 6.18 (95% CI: 1.94, 10.41); P = 0.004; I2 = 19%)] sub-scales of the Short Form 36-item questionnaire (SF-36). Qigong resulted in a significant improvement in the 6-min walk test [MD = 105.00m (95% CI: 19.53, 190.47)]. Exercise-based CR and AIT were associated with a significant increment in V̇O2peak, and AIT significantly reduced AF burden. Adverse events were few and one intervention-related serious adverse event was reported for exercise-based CR. Exercise led to improvements in HRQoL, exercise capacity, and reduced AF burden. The available exercise interventions for AF patients are few and heterogeneous. Future studies are needed for all types of exercise intervention in this patient group to (co-)develop an optimized exercise training intervention for AF patients.

Impact of redo ablation for atrial fibrillation on patient-reported outcomes and quality of life.

Catheter ablation for atrial fibrillation (AF) is frequently used for the purpose of rhythm control and improved quality of life (QoL). Although success rates are high, a significant proportion of patients require redo ablation. Data are scarce on patient-centered outcomes and QoL in patients undergoing redo AF ablation. We aimed to assess QoL and clinical outcomes using a large prospectively maintained patient-reported outcomes (PRO) registry. All patients undergoing redo AF ablation (2013-2016) at our center were enrolled in a prospective registry for outcomes and assessed for QoL using automated PRO surveys (baseline, 3 and 6 months after ablation, every 6 months thereafter). Data were collected over 3 years of follow-up. The atrial fibrillation symptom severity scale (AFSSS) was used as the main measure for QoL. Additional variables included patient-reported improvement, AF burden, and AF-related healthcare utilization including emergency room (ER) visits and hospitalizations. A total of 848 patients were included (28% females, mean age 63.8, 51% persistent AF). By automated PRO, significant improvement in QoL was noted (baseline median AFSSS of 12 [5-18] and ranged between 2 and 4 on subsequent assessments; p < .0001), with ≥70%of patients reported remarkable improvement in their AF-related symptoms. The proportion of patients in AF at the time of baseline survey was 36%, and this decreased to <8% across all time points during follow-up (p < .0001). AF burden was significantly reduced (including frequency and duration of episodes; p < .0001), with an associated decrease in healthcare utilization after 6 months from the time of ablation (including ER visits and hospitalizations; p < .0001). The proportion of patients on anticoagulants or antiarrhythmics decreased on follow-up across all time points (p < .0001 for all variables). Most patients derive significant QoL benefit from redo AF ablation; with reduction of both AF burden and healthcare utilization.

MHealth based patient-centered self-management reduces the burden and episodes of atrial fibrillation

Abstract Background There is a surging development of digital technologies for screening and diagnosis of atrial fibrillation (AF), nonetheless, how these digital technologies impact AF care remains unclear. Objectives The present study aimed to investigate the impact on AF episodes and arrhythmia burden of patient-centered self-management with using smart technologies, incorporating artificial intelligence (AI), wearable and mobile health (mHealth) technology for patient-centred self-management. Methods In this cohort study, we applied AI machine-learning (ML) model predicting AF prior to 4 hours of AF occurrence, while the timely monitoring of AF episodes with photoplethysmography (PPG) technology, and further confirmation of the diagnosis of AF with single-lead ECG, was based on wearable devices. These have been developed in AF screening study (stage 1 pre-mAFA) of Mobile Health technology for improved screening and optimizing integrated care in atrial fibrillation (mAFA II programme), while mHealth supported integrated care of AF was validated to reduce clinical events (stage 2 mAFA II cluster randomized trial). In this observational cohort, the subjects were in 2 groups: (i) subjects with monitored AF but without using mAFA (Group 1); (ii) subjects with monitored AF and using smart devices and mAFA for patient-centered self-management (Group 2). Adult subjects freely downloaded the mAFA AF App, with compatible devices, and were included into the study from across China between October 26, 2018 and Dec 1, 2021. Results From 3499461 subjects involving in AF population screening, there were 5904 subjects in Group 1 (mean age 57 years, SD,15 years; 80.7%, male), while 2667 subjects in Group 2 (51, 15; 89.7% male). The diagnosis of AF episodes was confirmed by single-lead ECG recordings, and decreased among those using mAFA in Group 2 (Confirmed AF: 602 in 1st quarter, 224 in 2nd quarter, 81 in 3rd quarter, 52 in 4th quarter) (all p value for trend&amp;lt;0.001). AF burden was significantly reduced over time (PPG: 26% on 1st month, 19% on 12th month; ECG: 3%, 0.7%, all p&amp;lt;0.001), while the average probability of AF occurrences by AI ML model prediction was decreased among those using mAFA in Group 2 (65%, 57%, p&amp;lt;0.001). The decreasing trend of AF burden over time was not seen in subjects with detected AF without mAFA (Group 1). On multivariate analysis, AI ML model driven mAFA-based upstream risk factor control significantly reduced the changes in AF burden of both Δ 6 month (adjusted OR, 95% CI, 0.51,0.43–0.59) and Δ 12 month (0.39,0.32–0.47, all p&amp;lt;0.001). Conclusion mHealth-AF care increased the adherence of using smart devices for AF detection. The incorporation of smart devices and AI tools into an AF clinical care pathway, effectively reduced AF burden and detected AF episodes, through appropriate rhythm control management and upstream risk factor control. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China