Higher Atrial Fibrillation Burden Research Articles

Preprocedural atrial fibrillation burden is associated with recurrence in patients undergoing atrial fibrillation ablation: findings from the ISOLATION AF Ablation Cohort Study

Abstract Background Non-invasive quantification of electrophysiological properties of the atria is increasingly used for outcome prediction in atrial fibrillation (AF) patients. Data on the benefit of the current classification of AF compared to AF burden based on single lead ECG measurements to predict AF recurrences are scarce. Objective This study sought to assess the predictive performance of low versus high AF burden compared to the conventional AF classification for predicting recurrences after AF catheter ablation. Methods A cross-sectional analysis was conducted in AF patients scheduled for catheter ablation included in the prospective multicenter ISOLATION cohort study between July 2020 and November 2022. Clinical characteristics, routine tests, blood tests and rhythm monitoring through single lead ECGs were collected prior to ablation. ECGs were recorded three times daily for four weeks, with additional measurements in case of the onset or relief of symptoms. The primary endpoint was "ablation success" defined as freedom from documented arrhythmia after the blanking period. Of 650 included patients, pre-procedural rhythm monitoring was available in 580. 261 patients had at least 14 days of ECG measurements and completed 12 months of follow-up. In these patients, we compared the recurrences after 12 months between paroxysmal and persistent AF and high versus low AF burden through survival analysis. Maximally selected rank statistics were used to determine the best cut-off value for AF burden. Results In 261 patients, the mean age was 64 ± 9 years, and 33.7% were female. Physicians classified 170 patients (65.1%) as paroxysmal AF and 91 (34.9%) as persistent AF based on medical history. The AF burden is shown in Figure 1. The optimal calculated cut-off value for AF burden was 42%. Out of 170 patients with paroxysmal AF, 17 (10%) had a burden of > 42%. Of the 91 patients with persistent AF, 35 (38%) had a burden of < 42%. After 12 months, a significant difference in recurrences was observed between patients with paroxysmal AF versus persistent AF (p= 0.015). Patients with high AF burden, had more recurrences after 12 months, than patients with a low AF burden (p= 0.006) (Figure 2). Conclusion Our preliminary results suggest that the addition of a new classification of AF based on burden might provide additional benefit in predicting AF recurrences after catheter ablation compared to the current existing classification and may improve prognostication. Completion of patient follow-up is necessary to determine the predictive value of AF burden derived from single lead ECGs for the prediction of AF recurrence.Figure 2.

Catheter ablation for persistent atrial fibrillation: patterns of recurrence and impact on quality of life and health care utilisation.

Patterns of atrial fibrillation (AF) recurrence post catheter ablation for persistent AF are not well described. This study aimed to describe the pattern of AF recurrence seen following catheter ablation for persistent AF (PsAF) and the implications for healthcare utilisation and quality of life. This was a post-hoc analysis of the CAPLA study, an international, multi-centre study that randomised 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. 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 randomisation groups (p=0.508). Median AF burden was 27.4% in PsAF recurrence and 0.9% in paroxysmal AF (PAF) recurrence (p<0.001). Patients with PsAF recurrence had lower baseline left ventricular ejection fraction (PsAF 50% vs PAF 60%, p<0.001) and larger left atrial volume (PsAF 54.2±19.3 ml/m² vs PAF 44.8±11.6 ml/m², p=0.008). Healthcare utilisation was significantly higher in PsAF (45 patients [78.9%]) vs PAF recurrence (45 patients [46.4%], p<0.001) and lowest in those without recurrence (17 patients [9.5%], p<0.001). Patients without AF recurrence had greater improvements in quality of life 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=0.012) or PsAF (Δ13.4±22.9 points, p<0.001) recurrence. 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 utilisation and antiarrhythmic drug use. The type of AF recurrence and AF burden may be considered important endpoints in clinical trials investigating ablation of PsAF.

Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke.

Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM). We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS2 score. Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P<0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively. The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.

Atrial fibrillation burden and timing of anticoagulation therapy in patients with screen-detected and clinically-diagnosed AF

Abstract Purpose We evaluated the impact of atrial fibrillation (AF) burden and timing of oral anticoagulation (OAC) therapy initiation on stroke risk in patients with screen-detected and clinically-diagnosed AF. Methods Consecutive patients aged ≥65 years attending medical outpatient clinics with or without known AF were prospectively enrolled for AF-screening using handheld single-lead ECG (AliveCor) from 12/2014 to 12/2017 (NCT02409654). Repeated screening was performed in patients with &amp;gt;1 visit during this period. Patients who participated in repeat screening were included in final analysis. Patients with previously known AF who were in AF in the initial screening and those with repeat screen-positivity were considered probably persistent AF, otherwise paroxysmal AF (single screen-positivity) or no AF (never screen-positive). Time from AF detection to initiation of OAC (Dx-to-Rx) was divided into two exposure levels, Dx-to-Rx ≤ 1 and &amp;gt;1 month. Ischemic stroke risk was estimated using adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression models, accounting for death as competing risk, adjusting for components of CHA2DS2VASC score and chronic renal disease, with no AF as reference and stratified according to AF burden and Dx-to-Rx. Results Of 11,972 patients enrolled, 3,853(32.2%) received repeated screening (mean age 76.7±7.3, female 47.5%), of which 3.7% (n=144) had screened-detected AF, 25.2% (n=972) previously known AF, 5.9% (n=226) clinically-diagnosed AF during follow-up, and 65.2% (n=2,511) no AF. Persistent AF was identified in 16.7% (n=644/3,853). Of patients with all AF categories, 55.1% (n=739/1,342) initiated OAC within 1 month after AF diagnosis. During a median follow-up period of 7.2(IQR: 6.1-7.5) years, compared to no AF, patients with paroxysmal AF and Dx-to-Rx ≤ 1m (aSHR=1.40, 95%CI:0.80-2.47) had similar low risk of ischemic stroke, while aSHR was highest for persistent AF and Dx-to-Rx &amp;gt;1m (aSHR=2.42, 95%CI:1.38-4.26), followed by persistent AF with Dx-to-Rx≤ 1m (aSHR=2.19,95%:1.47-3.28), and paroxysmal AF with Dx-to-Rx &amp;gt;1m (aSHR=2.00,95%CI:1.32-3.02) (Figure). Subgroup analysis revealed the effect of early initiation of OAC (P for interaction=0.936) and higher AF burden (P for interaction=0. 863) were consistent across screen-detected and clinically-diagnosed AF. Conclusion Among patients with screen-detected AF or clinically-diagnosed AF, lower AF burden and immediate initiation of OAC therapy were associated with reduction in risk of ischemic stroke. Early detection of AF by screening facilitating early OAC prophylaxis might improve clinical outcomes.Cumulative risk of ischemic stroke

Abstract 12517: The Racial Disparity Among the Clinical Outcomes, and Management Utilization in Atrial Fibrillation Patients: A Meta Analysis

Background: Although a higher burden of atrial fibrillation (AF) risk factors exists among the Black population, their prevalence of AF is less than White patients due to the under-diagnosis of minority groups and disparities in their management and outcomes. Objective: We aim to evaluate the disparities among the clinical outcomes post-AF, utilization of oral anticoagulants, and catheter ablation among Black and White race of patients. Methods: We systematically searched all electronic databases from inception until 27th May 2023. The primary outcome was all-cause mortality (ACM). Secondary outcomes include incidence of stroke, utilization of direct oral anticoagulants (DOAC), and catheter ablation. Results: A total of 11 studies with 1915540 patients were included in the final analysis (1771768 patients in the White group and 143772 patients of Black race). Pooled analysis of clinical outcomes shows that Black patients were having a higher risk of all-cause mortality (HR, 1.39(95%CI:1.09-1.75), P&lt;0.01). Similarly compared with White patients, the odds of initiating DOAC therapy (OR, 0.85(95%CI: 0.80-0.91), P&lt;0.001), and utilization of catheter ablation (OR, 0.69(95%CI: 0.52-0.86), P&lt;0.001) were significantly lower in Black patients. Conclusion: Black patients with atrial fibrillation are found to be associated with higher mortality and lower utilization of management approaches like use of DOAC, and catheter ablation.

Abstract 13214: Arrhythmic Burden After Bruton's Tyrosine Kinase Inhibitor Initiation and Major Cardiovascular Events

Background: Bruton’s tyrosine kinase inhibitors (BTKi) have dramatic efficacy against B cell malignancies. BTKi’s also cause cardiotoxic arrhythmias, including atrial fibrillation (AF) and ventricular arrhythmias (VA). Yet, the true burden and long term effects of arrhythmias after BTKi therapy are unknown. Research Question: In patients with suspected BTKi related arrhythmias, what is the relative AF burden? Does it prognosticate future events? Methods: Leveraging a cohort of consecutive B cell malignancy patients initiated on BTKi from 2009-2020, we identified patients with available ambulatory rhythm monitors. The primary outcome was AF burden after BTKi initiation. Secondary outcomes included VA burden, conduction blocks, and other arrhythmias of probable or definite BTKi association. Observed incident AF rates and burden with next generation BTKi’s were compared to ibrutinib. Multivariable regression and survival analysis were used to define factors associated with AF related hospitalizations and major adverse cardiac events (MACE), as well as the relationship between AF burden and mortality. Outcomes were stratified by high (≥5%) vs low (&lt;5%) AF burden. Results: Of 890 BTKi treated patients, 98 wore ambulatory rhythm monitors, including 38 on next generation BTKi’s [age 67.7 years, 24.2% prior AF]. Median duration BTKi use was 34 months. Among next generation BTKi treated patients, 8.7% developed incident AF compared to 25.5% with ibrutinib ( P =0.048). Ten patients (26.3%) developed symptomatic or &gt;1% PVCs, at a mean burden of 7.1% compared to eight patients (13.3%) with mean burden 9.4% on ibrutinib. In a multivariable model accounting for traditional CV risk factors, prior AF associated with increased post BTKi AF burden. In follow up, high AF burden associated with increased MACE (HR 3.49, P =0.001) and mortality (HR 3.2, P =0.002); Figure . Conclusions: In BTKi treated patients, cardiotoxic AF burden prognosticates future MACE and mortality.

Abstract 15518: What Monitoring Duration is Needed to Rule Out High Atrial Fibrillation Burden?

Introduction: Atrial fibrillation (AF) burden contributes to stroke risk. AF detection rates increase with monitoring duration, but the relationship between time to the first AF episode and AF burden has not been described. We aimed to identify AF free monitoring durations after which a given AF burden can be ruled out. Methods: We included all subjects without permanent AF (n=13,106, median age 65 years (IQR 51-74 years), 40.1% male) monitored for ≥14 days in 2021 in the USA with PocketECG (MEDICALgorithmics), a full disclosure mobile cardiac telemetry device. We graphed 14-day AF burden (% time in AF/total time) by time in days before detection of prespecified AF durations (&lt;30s (micro-AF), ≥30s-6 minutes, ≥6 minutes-1 hour and ≥1 hour in mutually exclusive strata) and calculated the 95th percentile of 14-day AF burden by time to first AF episode of different durations. Confidence intervals were estimated using bootstrapping with 1000 replications. Results: There were 5,605 patients with micro-AF episodes, 1,788 patients with 30s-6min AF episodes, 748 patients with 6 min-1 hour AF episodes and 227 patients with ≥1 hour AF episodes (Fig 1 a-d). The overall AF burden was higher in subjects with longer episodes, but decreased by time to first episode for all episode durations, Figure 1e-h. After 3 days of monitoring the 95th percentile for overall AF burden was 0.03% (95%CI 0.02-0.03%) in patients without micro-AF, 0.1% (95%CI 0.08-0.11% in patients without ≥30s AF, 0.4% (95%CI 0.3-0.4%) without ≥6-minute AF episodes, and 1.5% (95%CI 1.2-1.8%) without ≥1 hour episodes of AF. Conclusions: The probability of a high AF burden decreases as AF-free monitoring time increases, and AF free monitoring time can be used to inform the need for longer monitoring. When no AF episodes lasting ≥1 hour have been detected after 3 days of monitoring the probability of an AF burden &gt;2% can be effectively ruled out.

Predictors of New Onset Atrial Fibrillation Burden in the Critically Ill

Introduction: Atrial fibrillation (AF) is common in the intensive care unit (ICU) setting and has been associated with adverse outcomes. In this context, there is increasing research interest in AF burden as a predictor of subsequent adverse events. However, the pathophysiology and drivers of AF burden in the ICU are poorly understood. This study sought to evaluate the predictors of AF burden in critical illness-associated new-onset AF (CI-NOAF). Methods: Out of 7,030 admissions in a tertiary general ICU between December 2015 and September 2018, 309 patients developed CI-NOAF. AF burden was defined as the percentage of monitored time in AF, as extracted from hourly interpretations of continuous ECG monitoring. Low and high AF burden groups were defined relative to the median AF burden. Clinical, laboratory, and echocardiographic parameters were extracted, and multivariable modelling with binary logistic regression was performed to evaluate for independent associations with AF burden. Results: The median AF burden was 7.0%. Factors associated with increased AF burden were age, dyslipidaemia, chronic kidney disease, increased creatinine, CHA₂DS₂-VASc score, ICU admission diagnosis category, amiodarone administration, and left atrial area (LAA). Factors associated with lower AF burden were previous alcohol excess, burden of ventilation, the use of inotropes/vasopressors, and beta blockers. On multivariate analysis, increased LAA, chronic kidney disease, and amiodarone use were independently associated with increased AF burden, whereas beta blocker use was associated with lower AF burden. Conclusion: Left atrial size and chronic cardiovascular comorbidities appear to be the primary drivers of CI-NOAF burden, whereas factors related to acute illness and critical care intervention paradoxically did not appear to be a substantial driver of arrhythmia burden. Further research is needed regarding drivers of AF and the efficacy of rhythm control intervention in this unique setting.

Ambulatory Electrocardiography Monitoring for Early Discharge After Minimally Invasive Valve Surgery

IntroductionWe sought to compare outcomes after early discharge in patients with and without predischarge diagnosis of arrhythmia following minimally invasive valve surgery (MIVS). Materials and methodsWe retrospectively reviewed ambulatory electrocardiography (AECG) datasheets and medical records of patients discharged with 14-d AECG monitoring from our facility between October 2019 and March 2022 ≤ 3 d after MIVS. Baseline and clinical characteristics, arrhythmias during AECG monitoring, and 30-d adverse outcomes were reported for the population and stratified by presence or absence of predischarge arrhythmia. ResultsOf 41 patients discharged ≤3 d postoperatively of MIVS, 17 (41.5%) experienced predischarge arrhythmias and 24 (58.5%) did not. The population was predominantly male and White with a median age of 62 y [57, 70]. Baseline and clinical characteristics did not differ between subgroups. Most patients (92.7% [n = 38]) experienced one or more tachyarrhythmias during the AECG monitoring period. There were similar proportions of patients experiencing atrial fibrillation in both groups, but patients with predischarge arrhythmias had higher burden of atrial fibrillation on AECG monitoring (27.60% [6.57%, 100%] versus 1.65% [0.76%, 4.32%]; P = 0.004). The predischarge arrhythmia subgroup had higher proportions of patients experiencing nonsustained ventricular tachycardia but lower proportions experiencing supraventricular tachycardia. There were no mortalities within 30 d of surgery. Six (14.6%) patients were readmitted within 30 d with equal proportions of readmissions between subgroups (P = 0.662). ConclusionsEarly discharge timelines and noninvasive monitoring techniques can allow patients to return to their normal activities quicker in the comfort of their own home with no increased risk of morbidity or mortality.

Safety of Catheter Ablation Therapy for Atrial Fibrillation in Cardiac Amyloidosis.

Background Despite the high burden of atrial fibrillation in cardiac amyloidosis (CA), the safety of catheter ablation therapy in CA is not well established. We sought to examine short-term safety outcomes following atrial fibrillation ablation in patients with CA compared with matched patients with dilated cardiomyopathy (DCM). Methods and Results Using data from the National Inpatient Sample, we identified all hospitalizations for atrial fibrillation ablation from the fourth quarter of 2015 through 2019. Admissions for CA and DCM were matched in a 1:5 ratio using propensity scores based on the following sociodemographics: age, sex, race or ethnicity, payor, median income, comorbidities, and hospital characteristics. We compared in-hospital outcomes between both cardiomyopathies. We identified 1395 unweighted hospitalizations (representing 6750 national hospitalizations) for atrial fibrillation ablation, out of which 45 (3.2%) were admissions for CA. Compared with DCM, patients with CA were older (72.9 versus 65.1 years), had a higher burden of prior stroke (20.0% versus 8.6%) and chronic kidney disease (53.3% versus 33.6%), and were less likely to have a prior implantable cardioverter-defibrillator (4.4% versus 23.0%). We successfully matched 42 CAs to 210 DCM hospitalizations. After matching, there was no difference in total complications (14.3% versus 10.5%, P=0.60), length-of-stay (3.1 versus 2.1 days, P=0.23), home disposition (97.6% versus 96.2%, P=0.65), and total charges ($137 250 versus $133 910, P=0.24). Conclusions In this nationally representative study of atrial fibrillation catheter ablation in CA, short-term safety outcomes and complication rates were similar to a propensity score-matched cohort of DCM. Further studies exploring long-term safety outcomes are needed.

Early atrial fibrillation detection is associated with higher arrhythmic burden in patients with loop recorder after an embolic stroke of undetermined source

BackgroundAfter an embolic stroke of undetermined source (ESUS), long-term monitoring is recommended to start an anticoagulation therapy in patients with documented atrial fibrillation (AF). Literature is sparse about the AF burden following an ESUS, although this might have significant implications in terms of clinical management and therapeutic strategy. Our primary aim was to evaluate a possible association between early detection of AF (within 90 days from the ILR implantation) and higher AF burden. MethodsThis is a retrospective single-center study of 129 consecutive patients who received implantable loop recorders (ILRs) after an ESUS for detection of subclinical AF and their AF burden. ResultsMean age was 70.3 ± 10.4 years old (males: 51.9%). Atrial fibrillation was found in 40.3% of patients. Patients with AF were older, presented a higher CHAD2S2-Vasc Score and greater left atrial volume compared with patients without AF. The median AF burden was 1.2%; 59% of patients had the first AF episode within 90 days from the ILR implant while 41% experienced the first episode later than 90 days. The AF burden was significantly higher in the former group. Of note, the univariate analysis showed that only early AF detection was significantly associated with AF burden >1% (OR 20.0; 95% CI 1.68–238.6, p = 0.01). ConclusionsThe early AF detection was found to be significantly associated with a higher burden of AF.

Clinical impact of right ventricular pacing burden in patients with post-transcatheter aortic valve replacement permanent pacemaker implantation.

Patients who undergo permanent pacemaker (PPM) implantation after transcatheter aortic valve replacement (TAVR) have a worse outcome. The aim of this study was to identify risk factors of worse outcomes in patients with post-TAVR PPM implantation. This is a single-centre, retrospective study of consecutive patients who underwent post-TAVR PPM implantation from 11 March 2011 to 9 November 2019. Clinical outcomes were evaluated by landmark analysis with cut-off at 1 year after the PPM implantation. Of the 1389 patients underwent TAVR during the study duration and a total of 110 patients were included in the final analysis. Right ventricular pacing burden (RVPB) ≥ 30% at 1 year was associated with a higher likelihood of heart failure (HF) readmission [adjusted hazard ratio (aHR): 6.333; 95% confidence interval [CI]: 1.417-28.311; P = 0.016] and composite endpoint of overall death and/or HF (aHR: 2.453; 95% CI: 1.040-5.786; P = 0.040). The RVPB ≥30% at 1 year was associated with higher atrial fibrillation burden (24.1 ± 40.6% vs. 1.2 ± 5.3%; P = 0.013) and a decrease in left ventricular ejection fraction (-5.0 ± 9.8% vs. + 1.1 ± 7.9%; P = 0.005). The predicting factors of the RVPB ≥30% at 1 year were the presence of RVPB ≥40% at 1 month and the valve implantation depth measured from non-coronary cusp ≥4.0 mm (aHR: 57.808; 95% CI: 12.489-267.584; P < 0.001 and aHR: 6.817; 95% CI: 1.829-25.402; P = 0.004). The RVPB ≥30% at 1 year was associated with worse outcomes. Clinical benefit of minimal RV pacing algorithms and biventricular pacing needs to be investigated.

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.

Prediction of new onset atrial fibrillation recurrence or persistence with artificial intelligence: first insights of the PRAFAI study

Abstract Introduction Atrial fibrillation (AF) is the most prevalent arrhythmia in the world and it is associated with a high rate of cardiovascular morbidity and mortality. A higher burden of atrial fibrillation is related to more adverse cardiovascular events and the rhythm control strategy (maintenance or recovery of sinus rhythm) is particularly indicated in patients with paroxysmal symptomatic atrial fibrillation. All things considered, in order to select the optimal therapeutic strategy, it might be useful to accurately predict the probability of recurrence or permanence of AF after its onset. The predictive models implemented so far, show a limited predictive power or were built on samples of patients undergoing specific therapies. Thus, developing an specific model based on features derived from electronic health records (EHR) of patients with a first AF episode seems essential. Purpose To develop an artificial intelligence powered predictive model based on EHR variables in order to predict the AF recurrence after its onset. Methods The methodological design of the research is based on the analysis of secondary data from a retrospective cohort obtained from the EHR of a tertiary hospital. All new onset AF from 2015 to 2018 were identified by ICD codes, and a 2 years EHR driven follow-up was made to determine the AF recurrence or permanence of the arrhythmia in those patients. A systematic review was pursued to determine which features exhibited a greater predictive power for AF recurrence, and they were inquired to the system for the mentioned participants. After the standardization of the variables and a feature selection process, several missing value imputation methods and around 12 different Machine Learning algorithms were tested to predict the AF recurrence in a subset of patients who developed AF in the first semester of 2015, in order to select the algorithms with the highest prediction accuracy for further tests. Results 523 patients had an AF onset in the first semester of 2015. Among them, 310 (59.3%) had AF recurrence in a 2 years period. A support vector machine (SVM) algorithm with a median imputation method to handle missing values performed the best and had an 0.77 AUC in the training set and 0.71 in the test set. Hyperthyroidism, vasodilator drug use and obstructive sleep apnea were notoriously related to AF recurrence, while Ic antiarrhythmic drugs, AF ablation, cognitive impairment and anxiety were the most influential variables for the absence of recurrence. Classical AF recurrence factors such as age or left atrium diameter ratify their role in this setting. Conclusion A SVM Machine Learning algorithm discloses an accurate AF recurrence probability based on EHR features. Pharmacologic and epidemiological variables, added to classically assessed ones, seem to be specially related to this arrhythmic recurrence. Further research including the whole cohort features will probably improve the accuracy of this selected SVM algorithm. Funding Acknowledgement Type of funding sources: None.

375 ATRIAL FIBRILLATION BURDEN IN PATIENTS WITH IMPLANTABLE LOOP RECORDER AFTER A CRYPTOGENIC STROKE

Abstract Background After a cryptogenic stroke, long-term monitoring is recommended to start an anticoagulation therapy in patients with at least a documented paroxysm of subclinical atrial fibrillation (AF). Literature is sparse about the recurrence of AF (AF burden) after a cryptogenic stroke, but this might have significant implications in terms of therapeutic strategy. Methods This is a retrospective single-center study of 129 patients who received implantable loop recorders (ILRs), after a cryptogenic stroke, between March 2015 and March 2022. All patients were followed through remote monitoring for at least 6 months. The primary endpoint was AF detection; the secondary endpoints were the AF burden, the earliness (within or after 90 days from the ILR implant) of the first AF episode and if there was an association between these two variables. Results Mean age was 70.3 ± 10.4 years old (67 males, 51.9%); the mean value of left ventricular ejection fraction was 61% ± 5.8. Atrial fibrillation has been detected by ILR in 40.3% of patients (AF= 52 patients, NO AF= 77 patients) and each intracardiac electrogram was visually reviewed by two physicians. Median CHAD2S2-Vasc Score was 5 [4-6]; the median AF burden (assessed in 39 of the 52 patients) was 1.2% [0.1%-14.6%]; among these, 23 patients (59%) had the first episode within 90 days from the ILR implant versus 16 patients (41%) which experienced the first episode later than 90 days. AF burden was significantly higher in the first group (median 3.9% [1.2%-30.9%] vs 0.1% [0.03%-0.75%]; p=0.001). Of note the univariate analysis showed that both detection of the first AF episode within 90 days and echocardiographic findings of atrial disease (atrial dilation or diastolic dysfunction) were significantly associated with AF burden &amp;gt; 1% (about 7 hours for month) (respectively OR 16.5; 95% IC=3.34-81.21, p=0.001 and OR 4.5; 95% IC=1.2-17.5, p=0.03); at the multivariate analysis the significance was confirmed for the earliness of the first AF episode (OR 14.6; 95% IC=2.8-76.75, p=0.002). Conclusion In this small, retrospective study, AF was detected by ILR, after a cryptogenic stroke, in more than one third of patients. AF onset during the first 90 days might be a marker of a high AF burden and might highlight patients who could benefit from a rhythm control strategy of AF. Larger studies and clinical outcomes evaluation of these patients are required to confirm our results.

Abstract 10321: Safety of Catheter Ablation Therapy for Atrial Fibrillation in Cardiac Amyloidosis

Introduction: Despite a high burden of atrial fibrillation (AF) in cardiac amyloidosis (CA), the safety of catheter ablation therapy (CAT) in CA is not well established. We sought to examine short-term safety outcomes following CAT for AF in patients with CA compared to matched patients with dilated cardiomyopathy (DCM). Methods: Using data from National Inpatient Sample (NIS), we identified all hospitalizations for AF CAT from the fourth quarter of 2015 through 2019. We matched CA to DCM admissions in a 1:5 ratio using propensity scores based on sociodemographic, clinical comorbidities, and hospital characteristics. We compared in-hospital outcomes including mortality, procedural complications, discharge disposition, total charges, and length-of-stay Results: Overall, 1,395 unweighted hospitalizations (representing 6,750 national hospitalizations) for AF CAT were included in analysis, out of which 45 (3.2%) were admissions for CA. Compared to DCM, CA patients were older (72.9years vs 65.1years), had a higher burden of prior stroke (20.0% vs 8.6%) and chronic kidney disease (53.3% vs 33.6%), and were less likely to have a prior ICDs (4.4% vs 23.0%). We matched 42 amyloid hospitalizations to 210 DCM hospitalizations. After matching, there was no difference in rate of in-hospital mortality (0.24 vs 0.33%, p=0.77), home disposition (97.6% vs 96.2%, p=0.65), total procedural complications (14.3% vs 10.5%, p=0.60), length-of-stay (3.1 days vs 2.1 days, p = 0.23) and total hospital charges ($137,250 vs $133,910, p=0.24). Conclusions: In this contemporary study of CAT for AF in CA, short-term safety outcomes and complication rates were similar to a propensity-score-matched cohort of DCM. Further studies exploring long-term safety outcomes are needed.

Abstract 15438: Long-Term Outcomes of Bariatric Surgery in Patients With Atrial Fibrillation

Introduction: Obesity is associated with a higher burden of atrial fibrillation (AF) and related complications. Hypothesis: Bariatric surgery in patients with AF is associated with a reduction in mortality and long-term complications at 1 year. Methods: Patients with AF who underwent bariatric surgery were identified by analyzing the nationwide readmission database and incorporating the validated ICD-10 CM codes from October 2015 to December 2019. We performed the propensity score matching to adjust the confounders and cox proportional hazard regression to generate hazard ratios. Moreover, we generated Kaplan Meier curves for time-to-event analysis. The primary endpoint was all-cause mortality at 1 year, whereas secondary endpoints were ischemic stroke, major bleeding, and AF readmission at 1 year. Results: Out of 892488 obese patients with AF, 18766 underwent bariatric surgery. After propensity score matching, 18764 patients were identified in each group. At 1-year, patients undergoing bariatric surgery had a significant reduction in mortality (2.18% vs. 2.73%, HR: 0.91, 95% CI: 0.85-0.96, p=0.001). Additionally, risk of ischemic stroke was also reduced (1.98% vs. 2.29%, HR: 0.91, 95% CI: 0.86-0.97, p=0.01), whereas no difference was noted in AF readmissions (4.02% vs. 3.34%, HR: 0.97, 95% CI: 0.92-1.04, p=0.49) and risk of major bleeding was increased (5.74% vs. 3.42%, HR: 1.17, 95% CI: 1.10-1.25, p&lt;0.0001) at 1 year in AF patients with bariatric surgery. (Figure 1) Conclusions: Bariatric surgery in patients with AF was associated with a reduction in 1-year mortality and ischemic stroke. However, the risk of major bleeding was noted to be increased and no difference was noted in AF readmission at 1 year.

Abstract 10428: Probability of Atrial Fibrillation (AF) Diagnosis and Error in Estimation of Burden in People With Paroxysmal AF Based on the Duration of Monitoring

Introduction: In individuals with paroxysmal atrial fibrillation (PAF) undergoing heart rhythm monitoring, total duration of monitoring can influence both the probability of recognizing AF and estimation of burden. We estimate the probability of AF detection and quantify the error in burden estimation based on the duration of monitoring up to 10 days. Methods: Data included 5361 ECG patch recordings up to 14 days long with at least 1 episode of AF. 100 samples of pre-specified lengths were drawn at random from each recording. For each sample length, the probability of identifying any AF, and the AF burden over shorter periods of monitoring were determined. The absolute error in burden estimation over short monitoring divided by the true AF burden during up to 14 days of monitoring was used to determine relative deviation. We stratified the expected relative deviation and probability of detecting AF by high (&gt;10%), moderate (2-10%), or low (&lt;2%) true AF burden. Results: Estimated probability of detecting any AF was significantly affected by duration of monitoring (Fig): 1 day of monitoring identified 76% [75-77%], 52% [51-54%] and 35% [33-36%] of individuals with high, moderate, and low burden of AF. Relative deviation in the estimation of AF burden is also significantly impacted by monitoring duration with 1 day recording, with 0.89 [0.87-0.91], 1.45 [1.43-1.47], and 1.65 [1.63-1.67] for high, moderate, and low burden. Even for 7 days recording, the expected deviation is significant, with 0.31 [0.30-0.33], 0.60 [0.58-0.61], 0.79 [0.78-0.80] for high, moderate, and low burden (Fig). Conclusions: In people with PAF, known or unknown, the duration of continuous ECG recording can significantly impact both ability to diagnosis AF and accurate determination of AF burden. Even in individuals with true AF burden &gt;10%, 24 hours of monitoring will not detect AF in &gt;20% of people and provide an almost 90% relative error in the estimate of AF burden.

Epidemiology, risk profile, management, and outcome in geriatric patients with atrial fibrillation in two long-term care hospitals

Aim of this study was investigate the prevalence and incidence of atrial fibrillation (AF) and to describe the clinical characteristics, risk profiles, and types of anticoagulant therapy for stroke prevention and the clinical outcomes in persons admitted to a long-term care hospital. We conducted a retrospective cohort study using data from the electronic medical records of patients aged 65 years or older living in two long-term care hospitals between January 1, 2014 and October 31, 2017. Overall data from 1148 patients (mean age 84.1 ± 7.9 years, 74.2% women) were analyzed. At baseline, the median CHA2DS2-VASc score was 4 (IQR 3–5) and the HAS-BLED score 2 (IQR 2–3). We observed patients over a median period of 3.7 years. The point prevalence of AF was 29.6% (95% CI 25.8–33.7) on January 1, 2014. The 1-year cumulative incidence of de novo AF was 4.0% (2.8–5.6). Oral anticoagulants were prescribed in 48% of patients with AF. The cumulative incidence at 1 year for a composite outcome of TIA, stroke, or systemic arterial embolism was 0.6% (0.1–3.1) and 1.7% (0.5–4.6) and for bleeding 2.6% (0.9–6.2) and 1.8% (0.5–4.8) in patients with AF and oral anticoagulants or no oral anticoagulants, respectively. In long-term care hospital patients, we observed a high burden of AF. However, only about half of patients with AF received oral anticoagulation for stroke prevention.

Atrial Fibrillation Burden Specifically Determines Human Ventricular CellularRemodeling.

Atrial fibrillation (AF) can either be a consequence or an underlying mechanism of left ventricular systolic dysfunction. Patients included in the CASTLE-AF (Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF) trial who suffered from AF and left ventricular systolic dysfunction benefited from an AF burden<50% after catheter ablation compared with those patients with an AF burden >50%. This analysis tried to explain the clinical findings of the CASTLE-AF trial regarding AF burden in a "back-to-bench" approach. To study the ventricular effects of different AF burdens, experiments were performed using human ventricular induced pluripotent stem cell-derived cardiomyocytes undergoing invitro AF simulation. Epifluorescence microscopy, action potential measurements, and measurements of sarcomere regularity were conducted. Induced pluripotent stem cell-derived cardiomyocytes stimulated with AF burden of 60% or higher displayed typical hallmarks of heart failure. Ca2+ transient amplitude was significantly reduced indicating negative inotropic effects. Action potential duration was significantly prolonged, which represents a potential trigger for arrhythmias. A significant decrease of sarcomere regularity could explain impaired cardiac contractility in patients with high AF burden. These effects were more pronounced after 7days of AF simulation compared with 48 hours. Significant functional and structural alterations occurred at the cellular level at a threshold of ∼50% AF burden as it was observed to be harmful in the CASTLE-AF trial. Therefore, these translational results may help to understand the findings of the CASTLE-AF trial.