Reduction In Atrial Fibrillation Burden Research Articles

Diet and risk of atrial fibrillation: a systematic review.

Atrial fibrillation (AF) is the most prevalent sustained cardiac arrhythmia. Comprehensive modification of established AF risk factors combined with dietary interventions and breaking deleterious habits has been shown to reduce AF burden and recurrence. Numerous AF risk factors, such as diabetes, obesity or hypertension can be partially related to dietary and lifestyle choices. Therefore, dietary interventions may have potential as a therapeutic approach in AF. Based on available data, current guidelines recommend alcohol abstinence or reduction to decrease AF symptoms, burden, and progression, and do not indicate the need for caffeine abstention to prevent AF episodes (unless it is a trigger for AF symptoms). Uncertainty persists regarding harms or benefits of other dietary factors including chocolate, fish, salt, polyunsaturated and monounsaturated fatty acids, vitamins, and micronutrients. This article provides a systematic review of the association between AF and both dietary patterns and components. Additionally, it discusses potentially related mechanisms and introduces different strategies to assess patients' nutrition patterns, including mobile health solutions and diet indices. Finally, it highlights the gaps in knowledge requiring future investigation.

Modulation of NOX2 causes obesity-mediated atrial fibrillation.

Obesity is linked to an increased risk of atrial fibrillation (AF) via increased oxidative stress. While NADPH oxidase 2 (NOX2), a major source of oxidative stress and reactive oxygen species (ROS) in the heart, predisposes to AF, the underlying mechanisms remain unclear. Here, we studied NOX2-mediated ROS production in obesity-mediated AF using Nox2-knockout mice and mature human induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). Diet-induced obesity (DIO) mice and hiPSC-aCMs treated with palmitic acid (PA) were infused with a NOX blocker (apocynin) and a NOX2-specific inhibitor, respectively. We showed that NOX2 inhibition normalized atrial action potential duration and abrogated obesity-mediated ion channel remodeling with reduced AF burden. Unbiased transcriptomics analysis revealed that NOX2 mediates atrial remodeling in obesity-mediated AF in DIO mice, PA-treated hiPSC-aCMs, and human atrial tissue from obese individuals by upregulation of paired-like homeodomain transcription factor 2 (PITX2). Furthermore, hiPSC-aCMs treated with hydrogen peroxide, a NOX2 surrogate, displayed increased PITX2 expression, establishing a mechanistic link between increased NOX2-mediated ROS production and modulation of PITX2. Our findings offer insights into possible mechanisms through which obesity triggers AF and support NOX2 inhibition as a potential novel prophylactic or adjunctive therapy for patients with obesity-mediated AF.

Atrial fibrillation burden: a new outcome predictor and therapeutic target.

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is not a dichotomous disease trait. Technological innovations enable long-term rhythm monitoring in many patients and can estimate AF burden. These technologies are already used to detect and monitor AF. This review describes the relation between AF burden and outcomes and potential effects of AF burden reduction. A lower AF burden is associated with a lower risk of stroke and heart failure in patients with AF: stroke risk without anticoagulation is lower in patients with device-detected AF and a low AF burden (stroke rate 1%/year) than in patients with persistent and permanent AF (stroke rate 3%/year). Paroxysmal AF shows intermediate stroke rates (2%/year). Atrial fibrillation burden-reducing interventions can reduce cardiovascular outcomes in patients with AF: early rhythm control reduces cardiovascular events including stroke and heart failure in patients with recently diagnosed AF and cardiovascular conditions. In patients with heart failure and AF, early rhythm control and AF ablation, interventions that reduce AF burden, reduce mortality and heart failure events. Recent technological innovations allow to estimate AF burden in clinical care, creating opportunities and challenges. While evidence remains limited, the existing data already suggest that AF burden reduction could be a therapeutic goal. In addition to anticoagulation and treatment of cardiovascular conditions, AF burden reduction emerges as a therapeutic goal. Future research will define the AF burden that constitutes a relevant risk of stroke and heart failure. Technologies quantifying AF burden need careful validation to advance the field.

Long-Term Changes in Atrial Arrhythmia Burden After Renal Denervation Combined With Pulmonary Vein Isolation: SYMPLICITY-AF

BackgroundThe autonomic nervous system plays an important role in atrial fibrillation (AF) and hypertension. Renal denervation (RDN) lowers blood pressure (BP), but its role in AF is poorly understood. ObjectivesThe purpose of this study was to investigate whether RDN reduces AF recurrence after pulmonary vein isolation (PVI). MethodsThis study randomized patients from 8 centers (United States, Germany) with drug-refractory AF for treatment with PVI+RDN vs PVI alone. A multielectrode radiofrequency Spyral catheter system was used for RDN. Insertable cardiac monitors were used for continuous rhythm monitoring. The primary efficacy endpoint was ≥2 minutes of AF recurrence or repeat ablation during all follow-up. The secondary endpoints included atrial arrhythmia (AA) burden, discontinuation of class I/III antiarrhythmic drugs, and BP changes from baseline. ResultsA total of 70 patients with AF (52 paroxysmal, 18 persistent) and uncontrolled hypertension were randomized (RDN+PVI, n = 34; PVI, n = 36). At 3.5 years, 26.2% and 21.4% of patients in RDN+PVI and PVI groups, respectively, were free from the primary efficacy endpoint (log rank P = 0.73). Patients with mean ≥1 h/d AA had less daily AA burden after RDN+PVI vs PVI (4.1 hours vs 9.2 hours; P = 0.016). More patients discontinued class I/III antiarrhythmic drugs after RDN+PVI vs PVI (45% vs 14%; P = 0.040). At 1 year, systolic BP changed by −17.8 ± 12.8 mm Hg and −13.7 ± 18.8 mm Hg after RDN+PVI and PVI, respectively (P = 0.43). The composite safety endpoint was not significantly different between groups. ConclusionsIn patients with AF and uncontrolled BP, RDN+PVI did not prevent AF recurrence more than PVI alone. However, RDN+PVI may reduce AF burden and antiarrhythmic drug usage, but this needs further prospective validation.

Long-term effects of catheter ablation versus antiarrhythmic drugs on health-related quality of life in patients with atrial fibrillation: the CAPTAF randomized clinical trial revisited

Abstract Background Data on long-term effects of catheter ablation versus antiarrhythmic drugs (AAD) on health-related quality of life (HRQoL) and atrial fibrillation (AF) burden are limited. The study aimed to assess long-term HRQoL and rhythm data in symptomatic AF patients. Methods The 75 patients who underwent ablation and 74 receiving AAD in the Catheter Ablation compared with Pharmacological Therapy for Atrial Fibrillation (CAPTAF) trial were followed for 48 months comparison of General Health using 36-Item Short-Form Health Survey, time to first AF-episode ≥1 hour, and AF burden, recorded by implantable cardiac monitors. Results 147 patients completed follow-up, with seven crossovers in the ablation group and 34 crossovers in the AAD group. General Health improved by ablation, median 62 points at baseline to 79.2 points at follow-up (p<0.001), and by AAD from median 67 to 77 points (p<0.001), without treatment differences (p=0.77). Time to first AF-episode ≥1 hour was longer, median 257 days (ablation group) versus 180 days (AAD group), p=0.025. The cumulative AF burden during follow-up was lower in the ablation (median 0.3% [interquartile range 0, 1.4]) versus AAD group (1.6% [0.1, 11.0]), p=0.01. The cumulative reduction in AF burden compared with baseline was greater in the ablation (median -89.5% [-98.4, -51.3]) versus AAD group (-52.7% [-92.6, 263.6]), p=0.001). Conclusions HRQoL improvement at long-term did not differ between ablation and AAD despite a larger reduction in AF burden after ablation. The results should be interpreted in the light of a four times higher crossover rate in the AAD group.

Oral flecainide therapy and myocardial pacing: preliminary data from a prospective multicenter registry

Abstract Background Antiarrhythmic drugs, class I are widely used for prevention of atrial fibrillation recurrence. However, previous studies found that these drugs could affect pacing thresholds among pacemaker recipients. Aim of the study: evaluate short -term effect on myocardial pacing following therapy with oral flecainide (200 mg/daily). Methods 45 consecutive pacemaker recipients were prospectively enrolled in a multicenter registry. These patients had preserved left ventricular ejection fraction, a dual chamber pacemaker with symptomatic sustained high-rate atrial fibrillation episodes and stable output atrial and ventricular thresholds. Patients were followed with ambulatory and/or remote monitoring. Results mean age was 74±1 years, 48% pts were male and AF burden was 8±16%. Pacemaker implantation was performed 3.9±0.3 year before study enrollment. Three (6%) out of 45 patients were excluded due to drug sided effects including dyspnea (n=1), diplopia (n=1) and toxicity during acute renal insufficiency (n=1). Flecainide treatment was associated with a significant reduction of atrial fibrillation burden (from 8±16% to 5±12%, p<0.01). At 30 days follow-up since Flecainide starting therapy both atrial and ventricular sensing significantly decreased (3.6 ± 2.2 vs 3.4 ± 2.1mV p=0.01; 12.5±6.6 vs 11.8±6.3 mV p=0.01), while there was a slight increase of both atrial and ventricular capture thresholds (0.77±0.61V@0.4ms vs 0.80±0.42V@0.4ms p=0.01; 0.80±0.53V @0.4ms vs 0.83±0.33V @0.4ms p=0.01). No patient required pacemaker parameters reprogramming. Conclusions oral flecainide therapy among pacemaker recipients at 30 days follow-up seems to be safe and do not affect device function. Further studies with additional follow-up data are warranted.

Atrial fibrillation burden, symptoms and medication use after left bundle branch area pacing combined with AV-node ablation in patients with symptomatic atrial fibrillation

Abstract Background AV node ablation combined with permanent pacing is an established therapy for rate control in patients with symptomatic atrial fibrillation (AF) refractory or intolerant to pharmacological rate or rhythm control and not eligible for rhythm control by left atrial catheter ablation. The threshold for performing this so-called "pace-and-ablate" strategy has decreased since the introduction of conduction system pacing, and especially left bundle branch area pacing (LBBAP). Purpose To investigate the AF burden, AF related symptoms and anti-arrhythmic drug (AAD) use after AV-node ablation combined with LBBAP. Methods Consecutive patients with symptomatic AF, intolerant or refractory to pharmacological rate and symptom control and deemed not eligible for left atrial catheter ablation, were included. At baseline, AF related symptoms classified according to the EHRA classification and AAD use were scored. After DDD-pacemaker implantation with an LBBAP lead and subsequent AV-node ablation device detected AF burden was assessed six weeks, six months and twelve months later. AF burden at six weeks after AV-node ablation was considered the baseline measurement for AF burden. AF related symptoms and AAD use were collected at twelve months follow-up. Results Twenty-four patients (67% female, mean age 79±4 years) scheduled for pace-and-ablate therapy were prospectively included. Eighteen patients had persistent (75%) and three long-standing persistent (12.5%) AF with enlarged left atria (left-atrial volume index (LAVI) 52 ± 18ml/m2) and EHRA class IIb or higher in twenty (69%) patients. Twenty-three patients (96%) used at least one AAD with fifteen patients (63%) using >1 AAD at baseline, fig. 1. AF burden did not change at six months (-1.3 [-17, 15] %, p=0.87) and twelve months (-2.9 [-40,35] %, p=0.86) follow-up relative to six weeks follow-up, fig 2A. AF symptoms were significantly reduced with most patients in EHRA class I (6, 25%) or class IIa (17, 71%; p<0.001) at twelve months follow-up, fig 2B. There was a significant reduction in AAD use with fourteen patients (58%) using no AAD at twelve months follow-up and no patients using >1 AAD at twelve months follow up (p<0.001), fig 2C. Conclusion AV node ablation followed by permanent LBBAP did not reduce AF burden in an AF population with advanced disease. However, a significant reduction in AF symptoms and medication use was demonstrated with this therapy. Figure 2. AF burden (panel A), symptoms (panel B) and AAD use (panel C) at baseline and twelve months after ‘pace-and-ablate’ therapy. AF = atrial fibrillation; EHRA = EHRA = European Heart Rhythm Association symptom classification for AF; AAD = anti-arrhythmic drug. *relative to AF burden at six weeks follow-up.Baseline characteristicsBaseline and follow-up measurements

Catheter ablation for atrial fibrillation in heart failure with reduced ejection fraction patients: A meta-analysis

BackgroundThe optimal treatment of atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (HFrEF) remains unsettled. ObjectiveThe purpose of this study was to assess the efficacy of catheter ablation (CA) and medical therapy compared to medical therapy alone in patients with AF and HFrEF. MethodsWe performed a systematic review of randomized controlled trials (RCTs) comparing CA with guideline-directed medical therapy for AF in patients with HFrEF (left ventricular ejection fraction [LVEF] ≤ 40%). We systematically searched PubMed, Embase, and Cochrane for eligible trials. A random effects model was used to calculate the risk ratios (RRs) and mean differences (MDs), with 95% confidence intervals (CIs). ResultsSix RCTs comprising 1055 patients were included, of whom 530 (50.2%) were randomized to CA. Compared with medical therapy, CA was associated with a significant reduction in heart failure (HF) hospitalization (RR 0.57; 95% CI 0.45–0.72; P < .01), cardiovascular mortality (RR 0.46; 95% CI 0.31–0.70; P < .01), all-cause mortality (RR 0.53; 95% CI 0.36–0.78; P < .01), and AF burden (MD –29.8%; 95% CI –43.73% to –15.90%; P < .01). Also, there was a significant improvement in LVEF (MD 3.8%; 95% CI 1.6%–6.0%; P < .01) and quality of life (Minnesota Living with Heart Failure Questionnaire; MD –4.92 points; 95% CI –8.61 to –1.22 points; P < .01) in the ablation group. ConclusionIn this meta-analysis of RCTs of patients with AF and HFrEF, CA was associated with a reduction in HF hospitalization, cardiovascular mortality, and all-cause mortality as well as a significant improvement in LVEF and quality of life.

Comprehensive atrial fibrillation burden and symptom reduction post-ablation: insights from DECAAF II.

Traditional atrial fibrillation (AF) recurrence after catheter ablation is reported as a binary outcome. However, a paradigm shift towards a more granular definition, considering arrhythmic or symptomatic burden, is emerging. We hypothesize that ablation reduces AF burden independently of conventional recurrence status in patients with persistent AF, correlating with symptom burden reduction. Ninety-eight patients with persistent AF from the DECAAF II trial with pre-ablation follow-up were included. Patients recorded daily single-lead electrocardiogram (ECG) strips, defining AF burden as the proportion of AF days among total submitted ECG days. The primary outcome was atrial arrhythmia recurrence. The AF severity scale was administered pre-ablation and at 12 months post-ablation. At follow-up, 69 patients had atrial arrhythmia recurrence and 29 remained in sinus rhythm. These patients were categorized into a recurrence (n = 69) and a no-recurrence group (n = 29). Both groups had similar baseline characteristics, but recurrence patients were older (P = 0.005), had a higher prevalence of hyperlipidaemia (P = 0.007), and had a larger left atrial (LA) volume (P = 0.01). There was a reduction in AF burden in the recurrence group when compared with their pre-ablation burden (65 vs. 15%, P < 0.0001). Utah Stage 4 fibrosis and diabetes predicted less improvement in AF burden. The symptom severity score at 12 months post-ablation was significantly reduced compared with the pre-ablation score in the recurrence group, and there was a significant correlation between the reduction in symptom severity score and the reduction in AF burden (R = 0.39, P = 0.001). Catheter ablation reduces AF burden, irrespective of arrhythmia recurrence post-procedure. There is a strong correlation between AF burden reduction and symptom improvement post-ablation. Notably, elevated LA fibrosis impedes AF burden decrease following catheter ablation.

Abstract P502: Lifestyle Modification for Secondary Prevention of Atrial Fibrillation: A Pilot Study

Background: Addressing modifiable cardiovascular risk factors through lifestyle interventions may be effective for secondary atrial fibrillation (AF) prevention. Aims: To assess feasibility, acceptability, and preliminary effectiveness of an exercise and nutrition-based cardiac rehabilitation-like program for patients with symptomatic AF. Methods: We enrolled overweight (body mass index [BMI] ≥ 28 kg/m 2 ) adults aged ≥ 30 years with symptomatic AF in a 12-week cardiac lifestyle group program, which included 6 virtual and 6 in-person visits. All visits included discussion and education about nutrition, exercise, and behavior modification. In-person visits included supervised aerobic exercise and strength training. Patients were evaluated to assess health history, diet, and baseline cardiac risk factors. Outcomes at baseline and 12 weeks included feasibility of participation, change in weight and BMI, acceptability, and changes in survey-based AF burden and symptoms, and AF-related quality of life (QOL). Results: From 84 invitees, 11 (13.1%) were enrolled (mean age 64; baseline BMI 38 kg/m 2 ; 45% female); 9 (82%) completed the program. Patients attended an average of 9.7 (81%) visits (Range: 6-11). Mean weight loss was 9.1 pounds (Range: 0-16) and mean BMI decrease was 1.4 kg/m 2 (Range: 0-2.6). Nine of 11 patients completed baseline and follow-up surveys (Table) . Patients found the program helpful overall: all reported making diet and exercise changes during the program; 8 (89%) were confident in continuing dietary changes and 7 (77%) were confident in continuing exercise changes after the program. Patients reported decreased AF burden and symptoms, and increased QOL at the conclusion of the program (Table) . Conclusions: Participation in a cardiac rehab-like program was feasible and acceptable for overweight patients with symptomatic AF. Results suggest preliminary effectiveness of the program for reducing AF burden and symptoms and increasing quality of life.

Abstract 15388: Atrial Fibrillation Burden Reduction From Antiarrhythmic Drugs in Patients With Cardiac Implantable Electronic Devices

Introduction: Efficacy of rhythm control treatments for atrial fibrillation (AF) is usually measured by time to recurrent AF, however reduction in AF burden is a more clinically relevant endpoint. Cardiac implantable electronic devices (CIEDs) provide continuous rhythm monitoring that allows for highly accurate measures of AF burden. Ablation has been shown to reduce AF burden by &gt; 99% in CIED patients, but there are limited data on the impact of antiarrhythmic drug (AAD) therapy on AF burden. Methods: A single-center retrospective study of all CIED patients with new AAD initiation for AF between 4/2018-3/2022 was conducted. Patients with CIED-detected AF burden within 6 months pre- and 12 months post-AAD initiation were eligible for inclusion. CIED-detected AF burden was compared pre- and post-AAD initiation. Results: Of the 214 patients included in analysis (73.6 ± 11.8 yrs, 63% male, CHA 2 DS 2 -VASc 3.8 ± 1.6), there was a statistically significant reduction in AF burden following AAD initiation (pre-AAD 4.5% [IQR: 1.0%, 27.9%]; post-AAD 0.1% [IQR: 0%, 3.2%], p&lt;0.001). Of patients prescribed amiodarone (n=148, 69%), the median AF burden decreased from 3.6% [IQR: 1.0%, 28.0%] to 0.1% [IQR: 0.0%, 2.5%] (p&lt;0.001). Among patients on other AADs (flecainide n=22, 10%; sotolol n=21, 10%; dronedarone n=12, 6%; dofetilide n=8, 4%; propafenone n=3, 1%) the median AF burden decreased from 6.6% [IQR: 1.7%, 25.5%] to 0.2% [IQR: 0%, 3.5%] (p=0.028) (Figure). There was no significant difference in AF burden reduction between amiodarone and non-amiodarone AADs (amiodarone 90.9% [IQR: 0.0%, 100.0%], non-amiodarone AADs 74.0% [IQR: 0.0%, 99.9%], p=0.686). Conclusions: AADs significantly reduce CIED-measured AF burden, but this burden reduction is less than what is reported with ablation. There was no significant difference in AF burden reduction between cohorts of patients on amiodarone and non-amiodarone AADs.

Abstract 13924: Combined Gene Therapy Approach Targets Parasympathetic Signaling and Oxidative Stress to Reverse Pre-Existing Persistent Atrial Fibrillation in a Canine Model

Introduction: Atrial fibrillation (AF) is a multifactorial disease, with oxidative stress (NADPH oxidase 2, NOX2) and autonomic remodeling (hyperinnervation and parasympathetic signaling) playing an important role. Disrupting both mechanisms simultaneously with gene-based therapy may allow for reversal of established remodeling in AF. Hypothesis: Gene therapy aimed at attenuation of parasympathetic signaling (Gαi/o inhibitory peptides, GiGo_ct) and prevention of nerve sprouting (nerve growth factor short hairpin RNA, NGF shRNA) combined with reduction of oxidative stress (NOX2 shRNA) can reverse AF in a large animal chronic AF model. Methods: Chronic AF model was created by rapid atrial pacing (RAP) at 600bpm in 5 dogs, followed by gene therapy treatment (Panel A). A combination of NOX2 shRNA and GiGo_ct plasmids with (n=2) or without (n=3) NGF shRNA was injected in both atria followed by electroporation to facilitate gene delivery. Control RAP dogs did not receive gene (n=5) or underwent scrambled gene injection (n=6). AF burden was assessed over time and residual AF was recorded at terminal EP study. NOX2 and NGF knockdown and GiGo_ct expression were evaluated by PCR. Results: After 3.3±1.3 weeks of RAP, all 11 animals reached &gt;80% AF burden. Combined (NOX2+GiGo±NGF) gene therapy significantly reduced AF burden by 66% (p&lt;0.05) compared to scramble controls and by 38% (p&lt;0.05) compared to pre-treatment AF burden (Panel B). Residual AF after the treatment was slower and more organized than in controls (panel C). PCR analysis showed NOX2 and NGF downregulation and evidence of GiGo_ct expression. Conclusions: Gene-based attenuation of autonomic remodeling through inhibition of parasympathetic signaling and nerve sprouting, and reduction of oxidative stress by NOX2 downregulation may be effective at reversing AF. Development of optimized gene therapy to target multiple AF mechanisms simultaneously may lead to more effective treatments for persistent AF.

Serotonin antidepressants and atrial fibrillation burden from cardiac implantable electronic devices.

Depression and anxiety show a bidirectional relationship with atrial fibrillation (AF). Antidepressant use is associated with a reduction in the incidence of AF. However, no studies have examined the relationship between antidepressant use and AF burden (time in AF). This retrospective cohort study examined cardiac implantable device-detected AF episodes and their relationship with antidepressant use, among other treatment factors. Consecutive patients from the Western Health Cardiology Department attending pacemaker checks between 2015 and 2021 were included. Patients with permanent AF were excluded, yielding 285 patients with no or paroxysmal AF, with a total of 772 patient encounters. Generalized estimating equations were used to model two processes: binary AF (present/absent) and the number of days in AF for patients with AF. Each yearly increase with age was associated with an increase in the odds of developing AF (OR 1.03 [1.00-1.05], p = .027). Male gender conferred a reduction in AF incidence (OR 0.30 [0.13-0.68], p = .004). Digoxin use was associated with incident AF (OR 4.43 [1.07-18.4], p = .04). Sotalol and heart-failure beta blocker use were associated with a decrease in AF burden (IRR 0.30 [0.12-0.78], p = .013 and 0.33 [0.14-0.81], p = .015). Selective serotonin reuptake inhibitor antidepressant use was associated with reduced AF burden (IRR 0.27 [0.09-0.81], p = .019), as was selective serotonin/noradrenaline reuptake inhibitor use (IRR 0.07 [0.03-0.15], p < .001). Older age, female gender and digoxin are associated with a higher odds of developing incident AF. Sotalol, heart failure beta blockers and serotonin-based antidepressants are associated with reduced AF burden. Further prospective study into the effects of antidepressants on atrial arrhythmias is warranted.

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.