BACKGROUND:The effectiveness of catheter ablation for atrial fibrillation (AF) can only be fully assessed months after the procedure, and many complications do not present until after hospital discharge. Readily available means to monitor patients for quality assurance are hampered by the impracticality of following patients after they leave referral centers. OBJECTIVES:The objective of the study was to determine if a mobile app-based platform that interfaced directly with AF ablation patients using their smartphones might be feasible. METHODS:In the VIBRANT-AF (Volunteers to Investigate Best Results for Ablation and Novel Therapies for Atrial Fibrillation) study, AF catheter ablation patients were monitored with baseline and weekly SMS messages accompanied by mobile application-based questionnaires using the Eureka digital research platform. RESULTS:Among 493 participants enrolled from 17 sites, 4% reported an emergency department visit related to AF or the catheter ablation procedure. Among 236 followed for 1 year, participants completed a median of 25 (IQR: 7-42) electronic visits. A 2-fold increase in response rate was observed among those who completed at least 1 of the first 2 weeks of surveys. Recurrent AF at 1 year was reported in 30% of participants. The validated Atrial Fibrillation Effect on Quality of Life score improved from baseline to 6 months, with sustained improvement at 12 months. Validation of self-reported AF and complications in a subset of the cohort demonstrated substantial agreement with KardiaMobile electrocardiograms and electronic health record data, respectively. CONCLUSIONS:Direct patient-facing, mobile application-based surveillance is feasible following catheter AF ablation, with self-reported rates of effectiveness and complications similar to previous reports using conventional means. (Volunteers to Investigate Best Results for Ablation and Novel Therapies for Atrial Fibrillation [VIBRANT-AF]; NCT05504356).

Although pulmonary vein (PV) isolation (PVI) is an established atrial fibrillation (AF) treatment, its efficacy in persistent AF (PsAF) remains limited. Accordingly, post-PVI arrhythmia inducibility testing—mimicking non-PV ectopic activation—has often been employed during PsAF ablation, the value of non-inducibility as procedural endpoints or prognostic markers remains uncertain. Personalized atrial digital twins (DTs) can assess patient-specific arrhythmia inducibility; however, their clinical translation is hindered by the need for expert fibrosis characterization from MRI signals and substantial computational resources. To overcome these barriers, we leveraged deep learning (DL) to develop a practical framework for identifying potential non-PV trigger (NPVT) sites capable of inducing arrhythmia, without requiring patient-specific fibrosis thresholding or simulation. A comprehensive pacing-site set yielded significantly more patients’ DTs harboring potential NPVT sites than conventional catheter-based sites (85% vs. 54%). The DL model, InduceNet, trained on DT-derived results, accurately predicted potential NPVT sites (sensitivity 91%). This integrated DT–DL framework facilitates direct access, in clinical practice, to DT-derived insights into patient-specific potential NPVT sites, supporting more effective decision-making.

AIMS:Persistent atrial fibrillation (PsAF) is often refractory to pulmonary vein isolation, a well-established AF treatment, owing to the fibrosis-remodeled substrates sustaining reentries. Three-dimensional fibrosis distribution and atrial adiposity have been found to be essential contributors to PsAF arrhythmogenesis. We aimed to utilize late gadolinium enhancement (LGE)-MRI-derived personalized heart digital twins (DTs)-a recent promising tool for non-invasively assessing patient arrhythmogenesis-as well as contrast-enhanced cardiac computed tomography (CCT) images and electroanatomic maps (EAMs) to investigate relationships between fibrosis distribution, including endo-epi differences, adiposity infiltration, and electrophysiological abnormalities, and their influence on PsAF arrhythmogenic substrate. METHODS AND RESULTS:DTs incorporating fibrosis distribution were generated from consecutive PsAF patients' LGE-MRIs. Using rapid pacing, potential locations attracting reentries (LRs) were identified in DTs. CCTs were used to segment adipose tissue within pericardial sac and evaluate the distance from endocardial surface to closest adipose tissue (DEnCA). Bipolar- and unipolar-low-voltage area fractions (LVFs) were extracted from EAMs. Volumetric fibrosis fraction (FF) and surface FF on endocardial and epicardial surfaces at LRs and non-LRs were analyzed in relation to DEnCA and LVF. In 22 patients, adipose tissue volume correlated with BMI and CHA2DS2-VASc and, together with atrial-FF, predicted number of LRs. At LRs and non-LRs, while volumetric-FF was the sole determinant of LR classification, volumetric-FF correlated with endocardium-predominant fibrosis and bipolar-LVF. Endocardium-predominant fibrosis was independently linked to DEnCA. CONCLUSION:This study highlights the complex interactions between structural features, such as three-dimensional fibrosis distribution and atrial adiposity infiltration, electrophysiological features, and PsAF arrhythmogenesis.

BACKGROUND Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) therapies; however, in persistent AF (PsAF), characterized with fibrosis proliferation, its success is limited. Various extra-PVI strategies have also failed to improve outcome. Although PsAF entails inflammation-driven remodeling throughout the atria, the left atrium (LA) has been the main focus of ablative therapies. We hypothesized that the suboptimal outcomes of PsAF treatment are attributable to the arrhythmogenic role of the right atrium (RA). OBJECTIVE Using personalized digital twins (DTs), an emergent technology recently shown promise in non-invasively characterizing PsAF arrhythmogenesis, we aimed to mechanistically ascertain the difference in PsAF arrhythmogenesis between LA and RA post-PVI. METHODS From 61 patients with PsAF's late gadolinium enhancement magnetic resonance imaging, bi-atrial DTs incorporating fibrosis distribution were constructed. In each DT, following virtual PVI, PsAF arrhythmogenesis was assessed by identifying potential rotor-sustaining locations (LRs) following rapid pacing. Fibrotic and electrophysiological features of LRs were analyzed and compared between the LA and RA. RESULTS Of46 DTs with qualified images, 169 LRs were identified outside the PVI lesions, with substantial LR presence in the RA (66%). Fibrosis fraction within RA-LRs was higher than within LA-LRs. Fibrosis density and entropy and endocardial voltages at RA-LRs were comparable to LA-LRs. Age was found to be the independent determinant of PsAF arrhythmogenesis in RA. CONCLUSION DT analysis demonstrated that the RA contributed equally to PsAF arrhythmogenesis after PVI and exhibited fibrotic and electrophysiological features comparable to those of the LA post-PVI. Controlling RA arrhythmogenesis may be essential for PsAF management.

Pulmonary vein isolation (PVI), the standard-of-care for atrial fibrillation (AF), is effective even in some persistent AF (PsAF) patients despite atrial fibrosis proliferation, suggesting that PVI could not only be isolating triggers but diminishing arrhythmogenic substrates. Left atrial (LA) posterior wall isolation is the prevalent adjunctive strategy aiming to address PsAF arrhythmogenesis, however, its outcomes vary widely. To explore why current PsAF ablation treatments have limited success and under what circumstances each treatment is most effective, we utilized patient-specific heart digital twins of PsAF patients incorporating fibrosis distributions to virtually implement versions of PVI (individual ostial to wide antral) and posterior wall isolation. In most digital-twins (60%) PVI greatly decreased LA substrate arrhythmogenicity without the need of wider lesions or posterior wall isolation. Using digital-twin findings, a strategy was developed to stratify PsAF patients to an appropriate ablation option based on fibrosis features, thus potentially avoiding unnecessary heart damage.

BackgroundRelationship between glucagon-like peptide-1 receptor agonist (GLP-1 RA) use prior to atrial fibrillation (AF) ablation and subsequent AF recurrence is not well-understood.ObjectivesThis study investigated the effects of GLP-1 RA use within 1 year before ablation and its association with AF recurrence and associated outcomes.MethodsThe TriNetX research database was used to identify patients aged ≥18 years undergoing AF ablation (2014-2023). Patients were categorized into 2 groups, and propensity score matching (1:1) between preablation GLP-1 RA users and nonusers was performed based on demographics, comorbidities, body mass index, laboratory tests, AF subtype, and medications. Primary outcome was composite of cardioversion, new antiarrhythmic drug therapy, or repeat AF ablation after a 3-month blanking period following the index ablation. Additional outcomes included ischemic stroke, all-cause hospitalization, and mortality during 12-month follow-up period.ResultsAfter 1:1 propensity score matching, the study cohort comprised 1,625 GLP-1 RA users and 1,625 matched GLP-1 RA nonusers. Preablation GLP-1 RA therapy was not associated with a lower risk of cardioversion, new AAD therapy, and repeat AF ablation after the index procedure (HR: 1.04 [95% CI: 0.92-1.19]; log-rank P = 0.51). Furthermore, the risk of ischemic stroke, all-cause hospitalization, and mortality during the 12-month follow-up period did not differ between the 2 groups.ConclusionsThese findings suggest that preprocedural use of GLP-1 RAs is not associated with a reduced risk of AF recurrence or associated adverse outcomes following ablation, and underscore the need for future research to determine whether these agents improve outcome in AF patients.

Abstract Introduction Late gadolinium enhancement MRI (LGE MRI) is a common method for the evaluation of the atrial substrate in atrial fibrillation (AF) patients. The extent of LGE is associated with atrial cardiomyopathy and ablation outcomes. However, previous studies have yielded inconsistent results in detecting low voltage areas (LVA) using bipolar electroanatomical mapping (EAM) in LGE regions. Objective Conduct a thorough analysis of the bipolar and unipolar voltage in LGE areas and its relationship with the voltage in non-LGE areas, utilizing high-density (HD) EAM generated by a multipolar HD-mapping catheter. Methods In this study, 20 patients undergoing AF ablation were examined using LGE-MRI. A 3D mesh integrating LGE data was generated. HD-EAM (> 4000 points) was performed in sinus rhythm. The EAM map and MRI mesh underwent manual alignment and registration. Using a nearest neighbor algorithm, EAM points nearest to LGE areas were identified, and the corresponding unipolar and bipolar voltage values, along with LGE voxel intensity, were exported for analysis. Results LGE areas exhibited a median bipolar voltage amplitude of 0.93 mV, median unipolar voltage of 1.73 mV. In contrast, areas without enhancement displayed median bipolar voltage of 2.33 mV, unipolar voltage of 3.58 mV. We observed a variation in voltage amplitudes across the different LGE areas: bipolar voltage ranged from 0.04 to 2.51 mV and unipolar voltage from 0.22 to 3.75 mV. This variation strongly correlated with voxel intensity in LGE areas (correlation coefficient r = -0.86 [p <0.001]). Irrespective of the voltage amplitude in the examined LGE areas, a significant voltage drop was observed, with an average reduction of 54% in bipolar and 51% in unipolar voltages, compared to the amplitudes in non-LGE areas within the same atria. Conclusion Variations in bipolar and unipolar voltage within LGE areas are significantly correlated with local voxel intensity. Despite the inconsistent overlap with the predefined bipolar threshold for LVA, LGE regions exhibit a pronounced and consistent reduction in both bipolar and unipolar voltage compared to non-LGE areas. This pattern suggests notable electrophysiological changes in these areas. These insights underscore the need for further investigation to better understand the implications and mechanisms underlying these alterations in LGE regions.

BACKGROUND Catheter ablation is a mainstay of atrial fibrillation (AF) treatment. Acute pericarditis after ablation is 1 of the frequently observed complications. There is a significant lack of data on the incidence and predictors of postablation pericarditis. OBJECTIVES This study examines the incidence, characteristics, and predictors of pericarditis after AF ablation. METHODS Patients undergoing AF ablation from January 1, 2016, to March 31, 2022, at Johns Hopkins were prospectively enrolled in an AF ablation registry. A clinical diagnosis of acute pericarditis was established in accordance with 2015 European Society of Cardiology guidelines by the presence of at least 2 of the following characteristics: pleuritic chest pain, friction rub, typical electrocardiographic changes, or pericardial effusion within 3 months after the ablation procedure. RESULTS Of 1,540 patients who underwent AF ablation, 57 patients (3.7%) developed acute pericarditis. Baseline clinical characteristics including age, sex, and body mass index were comparable between the pericarditis and nonpericarditis groups. The median time to symptom onset was 1 day. Electrocardiographic changes were observed in 34 (59.6%) patients, pericardial effusion developed in 7 (12%) patients, and the mean duration of medical treatment was 7 days (25th-75th percentile: 3-14 days). Most pericarditis cases were treated medically with disease-specific nonsteroidal anti-inflammatory drugs (100%) and colchicine (81%). Effusion with tamponade necessitating pericardiocentesis was observed in 4 (7%) patients. Radiofrequency (RF) ablation was performed in 869 (58.6%) patients in the nonpericarditis group and 39 (68.4%) patients with pericarditis; cryoballoon ablation was performed in 486 (32.8%) patients in the nonpericarditis group and 11 (19.3%) patients with pericarditis. Multivariable logistic regression analysis identified RF ablation (OR: 2.09; 95% CI: 1.07-4.08; P = 0.03) as an independent predictor of acute pericarditis after AF ablation, whereas age per unit increase was associated with a decreased risk (OR: 0.97; 95% CI: 0.95-0.995; P = 0.02). CONCLUSIONS The incidence of acute pericarditis after catheter ablation in our study population was 3.7%. RF ablation and younger age were independent risk factors for postablation acute pericarditis.