Prediction of incident atrial fibrillation using deep learning, clinical models and polygenic scores.

BACKGROUND AND AIMS: Deep learning applied to electrocardiograms (ECG-AI) is an emerging approach for predicting atrial fibrillation or flutter (AF). This study introduces an ECG-AI model developed and tested at a tertiary cardiac centre, comparing its performance with clinical and AF polygenic scores (PGS). METHODS: ECG in sinus rhythm from the Montreal Heart Institute were analysed, excluding those from patients with preexisting AF. The primary outcome was incident AF at 5 years. An ECG-AI model was developed by splitting patients into non-overlapping datasets: 70% for training, 10% for validation, and 20% for testing. Performance of ECG-AI, clinical models and PGS was assessed in the test dataset. The ECG-AI model was externally validated in the Medical Information Mart for Intensive Care-IV (MIMIC-IV) hospital dataset. RESULTS: A total of 669,782 ECGs from 145,323 patients were included. Mean age was 61±15 years, and 58% were male. The primary outcome was observed in 15% of patients and the ECG-AI model showed an area under the receiver operating characteristic curve (AUC) of 0.78. In time-to-event analysis including the first ECG, ECG-AI inference of high risk identified 26% of the population with a 4.3-fold increased risk of incident AF (95% confidence interval 4.02-4.57). In a subgroup analysis of 2,301 patients, ECG-AI outperformed CHARGE-AF (AUC=0.62) and PGS (AUC=0.59). Adding PGS and CHARGE-AF to ECG-AI improved goodness-of-fit (likelihood ratio test p<0.001), with minimal changes to the AUC (0.76-0.77). In the external validation cohort (mean age 59±18 years, 47% male, median follow-up 1.1 year) ECG-AI model performance= remained consistent (AUC=0.77). CONCLUSIONS: ECG-AI provides an accurate tool to predict new-onset AF in a tertiary cardiac centre, surpassing clinical and polygenic scores.

Gender and contemporary risk of adverse events in atrial fibrillation.

BACKGROUND AND AIMS: The role of gender in decision-making for oral anticoagulation in patients with atrial fibrillation (AF) remains controversial. METHODS: The population cohort study used electronic healthcare records of 16 587 749 patients from UK primary care (2005-2020). Primary (composite of all-cause mortality, ischaemic stroke, or arterial thromboembolism) and secondary outcomes were analysed using Cox hazard ratios (HR), adjusted for age, socioeconomic status, and comorbidities. RESULTS: 78 852 patients were included with AF, aged 40-75 years, no prior stroke, and no prescription of oral anticoagulants. 28 590 (36.3%) were women, and 50 262 (63.7%) men. Median age was 65.7 years (interquartile range 58.5-70.9), with women being older and having other differences in comorbidities. During a total follow-up of 431 086 patient-years, women had a lower adjusted primary outcome rate with HR 0.89 vs. men (95% confidence interval [CI] 0.87-0.92; P < .001) and HR 0.87 after censoring for oral anticoagulation (95% CI 0.83-0.91; P < .001). This was driven by lower mortality in women (HR 0.86, 95% CI 0.83-0.89; P < .001). No difference was identified between women and men for the secondary outcomes of ischaemic stroke or arterial thromboembolism (adjusted HR 1.00, 95% CI 0.94-1.07; P = .87), any stroke or any thromboembolism (adjusted HR 1.02, 95% CI 0.96-1.07; P = .58), and incident vascular dementia (adjusted HR 1.13, 95% CI 0.97-1.32; P = .11). Clinical risk scores were only modest predictors of outcomes, with CHA2DS2-VA (ignoring gender) superior to CHA2DS2-VASc for primary outcomes in this population (receiver operating characteristic curve area 0.651 vs. 0.639; P < .001) and no interaction with gender (P = .45). CONCLUSIONS: Removal of gender from clinical risk scoring could simplify the approach to which patients with AF should be offered oral anticoagulation.

Atrial Fibrillation and Semaglutide Effects in Obesity-Related Heart Failure With Preserved Ejection Fraction: STEP-HFpEF Program.

BACKGROUND: Obesity is a key factor in the development and progression of both heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF). In the STEP-HFpEF Program (comprising the STEP-HFpEF [Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity] and STEP-HFpEF DM [Research Study to Look at How Well Semaglutide Works in People Living With Heart Failure, Obesity and Type 2 Diabetes] trials), once-weekly semaglutide 2.4 mg improved HF-related symptoms, physical limitations, and exercise function and reduced body weight in patients with obesity-related HFpEF. Whether the effects of semaglutide in this patient group differ in participants with and without AF (and across various AF types) has not been fully examined. OBJECTIVES: The goals of this study were: 1) to evaluate baseline characteristics and clinical features of patients with obesity-related HFpEF with and without a history of AF; and 2) to determine if the efficacy of semaglutide across all key trial outcomes are influenced by baseline history of AF (and AF types) in the STEP-HFpEF Program. METHODS: This was a secondary analysis of pooled data from the STEP-HFpEF and STEP-HFpEF DM trials. Patients with heart failure, left ventricular ejection fraction ≥45%, body mass index ≥30 kg/m2, and Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS) <90 points were randomized 1:1 to receive once-weekly semaglutide 2.4 mg or matching placebo for 52 weeks. Dual primary endpoints (change in KCCQ-CSS and percent change in body weight), confirmatory secondary endpoints (change in 6-minute walk distance; hierarchical composite endpoint comprising all-cause death, HF events, thresholds of change in KCCQ-CSS, and 6-minute walk distance; and C-reactive protein [CRP]), and exploratory endpoint (change in N-terminal pro-B-type natriuretic peptide [NT-proBNP]) were examined according to investigator-reported history of AF (yes/no). Responder analyses examined the proportions of patients who experienced a ≥5-, ≥10, ≥15, and ≥20-point improvement in KCCQ-CSS per history of AF. RESULTS: Of the 1,145 participants, 518 (45%) had a history of AF (40% paroxysmal, 24% persistent AF, and 35% permanent AF) and 627 (55%) did not. Participants with (vs without) AF were older, more often male, had higher NT-proBNP levels, included a higher proportion of those with NYHA functional class III symptoms, and used more antithrombotic therapies, beta-blockers, and diuretics. Semaglutide led to larger improvements in KCCQ-CSS (11.5 points [95% CI: 8.3-14.8] vs 4.3 points [95% CI: 1.3-7.2]; P interaction = 0.001) and the hierarchal composite endpoint (win ratio of 2.25 [95% CI: 1.79-2.83] vs 1.30 [95% CI: 1.06-1.59]; P interaction < 0.001) in participants with AF vs without AF, respectively. The proportions of patients receiving semaglutide vs those receiving placebo experiencing ≥5-, ≥10-, ≥15-, and ≥20-point improvement in KCCQ-CSS were also higher in those with (vs without) AF (all P interaction values <0.05). Semaglutide consistently reduced CRP, NT-proBNP, and body weight regardless of AF status (all P interaction values not significant). There were fewer serious adverse events and serious cardiac disorders in participants treated with semaglutide vs placebo irrespective of AF history. CONCLUSIONS: In the STEP-HFpEF Program, AF was observed in nearly one-half of patients with obesity-related HFpEF and was associated with several features of more advanced HF. Treatment with semaglutide led to significant improvements in HF-related symptoms, physical limitations, and exercise function, as well as reductions in weight, CRP, and NT-proBNP in people with and without AF and across AF types. The magnitude of semaglutide-mediated improvements in HF-related symptoms and physical limitations was more pronounced in those with AF vs without AF at baseline.(Research Study to Investigate How Well Semaglutide Works in People Living With Heart Failure and Obesity [STEP-HFpEF; NCT04788511; Research Study to Look at How Well Semaglutide Works in People Living With Heart Failure, Obesity and Type 2 Diabetes [STEP-HFpEF DM; NCT04916470]).

Endoscopic Ultrasound for the Evaluation of Esophageal Injury After Catheter Ablation for Atrial Fibrillation.

BACKGROUND & AIM: Atrial fibrillation (AF) ablation is an increasingly utilized rhythm control strategy that can damage adjacent structures in the mediastinum including the esophagus. Atrioesophageal fistulas and esophagopericardial fistulas are life-threatening complications that are thought to progress from early esophageal mucosal injury (EI). Endoscopic ultrasound (EUS) has been proposed as a superior method than EGD to survey EI and damage to deeper structures. We aim to evaluate the safety of EUS in categorizing post-ablation EI and quantify EUS-detected lesions and their correlation with injury severity and clinical course. METHODS: 234 consecutive patients between 2006-2020 who underwent AF ablation followed by EUS for the purpose of EI screening were retrospectively reviewed. Kansas City Classification (KCC) was used to classify EI (Type 1, Type 2a/b, Type 3a/b). RESULTS: EUS identified pleural effusions (31.6%) of patients, mediastinal adventitia changes (22.2%), mediastinal lymphadenopathy (14.1%), pulmonary vein changes (10.6%), and esophageal wall changes (7.7%). EGD revealed 175 (75%) patients without and 59 (25%) with EI. Patients with Type 2a/b EI and no EI were compared with multivariate logistic regression, and the presence of esophageal wall abnormality on EUS with OR 72.85 (95% CI 13.9-380.7), female sex with OR 3.97 (95% CI 1.3-12.3), and number of energy deliveries with OR 1.01 (95% CI 1.003-1.03), were associated with the presence EI type 2a or 2b. Pre-ablation PPI use was not associated with decreased risk of EI. CONCLUSIONS: EUS safely assesses mediastinal damage after ablation for atrial fibrillation and may excel over EGD in evaluating mucosal lesions of uncertain significance, with reduced risk of gas embolization in the setting of a full thickness injury (entero-vascular fistula). We propose an EUS-first guided approach to post-AF ablation examination, followed by EGD if it is safe to do so.

[Detection model of atrial fibrillation based on multi-branch and multi-scale convolutional networks].

Atrial fibrillation (AF) is a life-threatening heart condition, and its early detection and treatment have garnered significant attention from physicians in recent years. Traditional methods of detecting AF heavily rely on doctor's diagnosis based on electrocardiograms (ECGs), but prolonged analysis of ECG signals is very time-consuming. This paper designs an AF detection model based on the Inception module, constructing multi-branch detection channels to process raw ECG signals, gradient signals, and frequency signals during AF. The model efficiently extracted QRS complex and RR interval features using gradient signals, extracted P-wave and f-wave features using frequency signals, and used raw signals to supplement missing information. The multi-scale convolutional kernels in the Inception module provided various receptive fields and performed comprehensive analysis of the multi-branch results, enabling early AF detection. Compared to current machine learning algorithms that use only RR interval and heart rate variability features, the proposed algorithm additionally employed frequency features, making fuller use of the information within the signals. For deep learning methods using raw and frequency signals, this paper introduced an enhanced method for the QRS complex, allowing the network to extract features more effectively. By using a multi-branch input mode, the model comprehensively considered irregular RR intervals and P-wave and f-wave features in AF. Testing on the MIT-BIH AF database showed that the inter-patient detection accuracy was 96.89%, sensitivity was 97.72%, and specificity was 95.88%. The proposed model demonstrates excellent performance and can achieve automatic AF detection.

Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Off-pump Coronary Artery Bypass Graft.

OBJECTIVE: Postoperative atrial fibrillation (POAF) is associated with increased morbidity, mortality, and length of hospital stay. The objective of this study was to assess the utility of left atrial strain (LAS) to predict POAF in patients undergoing off-pump coronary artery bypass grafting (OPCABG). DESIGN: Retrospective observational study. SETTING: Tertiary care hospital. PARTICIPANTS: 103 patients undergoing OPCABG. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: In addition to comprehensive transthoracic echocardiography, LAS was measured for reservoir (R), conduction (CD), and contraction (CT) components. POAF was defined as new electrocardiographic evidence of AF requiring treatment. Logistic regression was done to assess factors associated with POAF. The diagnostic accuracy of variables in predicting POAF was assessed by receiver operating characteristic analysis. POAF was documented in 24 (23.3%) patients. There was no difference in ejection fraction, average global longitudinal strain, or proportion of left ventricular diastolic dysfunction grades between patients with POAF and patients without POAF. All three components of LAS: LAS R (19.2 ± 4.7 v 23.5 ± 4.8, p < 0.001), LAS CD (8.9 ± 3.7 v 12.3 ± 4.8, p = 0.1), and LAS CT (10.3 ± 3.9 v 12.1 ± 4.1, p = 0.04), were significantly lower among patients with POAF compared with patients without POAF, respectively. According to univariate analysis, all components of LAS were statistically significant predictors of POAF. In multivariate analysis, only age (odds ratio = 1.08, p = 0.025) and LAS R (odds ratio = 0.84, p = 0.004) were independently associated with POAF. LAS R was a better predictor of POAF, with an area under the curve (AUC) of 0.758, than LAS CD (AUC = 0.67) and LAS CT (AUC = 0.62). LAS R had an optimal cutoff of 23% with sensitivity of 95.8% (confidence interval: 78.9-99.9%) and specificity of 49.4% (37.9-60.9%) to predict POAF. CONCLUSIONS: LAS R is a significant predictor of POAF, and its use can be recommended for screening of OPCABG patients at high risk of POAF.

Comparison of Amiodarone Loading Dosage in the Treatment of Postoperative Atrial Fibrillation: High Versus Standard Dose Treatment.

BACKGROUND: Postoperative atrial fibrillation (POAF) is associated with poor outcomes, including hemodynamic instability, stroke, myocardial infarction, and death. In hemodynamic stable patients, the rhythm-control strategy is more advantageous than rate control. Current standard intravenous amiodarone administration has limited success and a delayed effect; the acute success rate is 44% (8-12 h to several days). PURPOSE: The aim of this study was to evaluate the effectiveness of higher amiodarone loading dosage to restore sinus rhythm in patients with POAF after noncardiac surgery. METHODS: This is a prospective, randomized, controlled single-center study. The study included 39 patients with POAF, divided into group I (n=27) (intravenous 600 mg amiodarone loading dosage over 2 h and infusion of 50 mg/h over a 24-h period) and group II (n=12) (standard protocol; 300 mg of bolus intravenously in 30 min and infusion of 50 mg/h over a 24-h period). The primary endpoint of the study was a restoration of sinus rhythm at the 24th hour. RESULTS: Baseline clinical, laboratory and echocardiographic characteristics of both groups were similar. The patients with higher loading amiodarone dosage had earlier restoration of sinus rhythm (2.38±1.41 vs 8.66±2.87 h, respectively; p=0.015). There was no significant difference in achieving sinus rhythm at the 24th hour between both groups. CONCLUSION: Higher loading amiodarone dosage increased early conversions to sinus rhythm compared with standard amiodarone protocol in patients with POAF.

Anticoagulation in device-detected atrial fibrillation with or without vascular disease: a combined analysis of the NOAH-AFNET 6 and ARTESiA trials.

BACKGROUND AND AIMS: The optimal antithrombotic therapy in patients with device-detected atrial fibrillation (DDAF) is unknown. Concomitant vascular disease can modify the benefits and risks of anticoagulation. METHODS: These pre-specified analyses of the NOAH-AFNET 6 (n=2534 patients) and ARTESiA (n=4012 patients) trials compared anticoagulation to no anticoagulation in patients with DDAF with or without vascular disease, defined as prior stroke/transient ischemic attack, coronary or peripheral artery disease. Efficacy outcomes were the primary outcomes of both trials, a composite of stroke, systemic arterial embolism (SE), myocardial infarction, pulmonary embolism or cardiovascular death, and stroke or SE. Safety outcomes were major bleeding or major bleeding and death. RESULTS: In patients with vascular disease (NOAH-AFNET 6 56%, ARTESiA 46.0%), stroke, myocardial infarction, systemic or pulmonary embolism, or cardiovascular death occurred at 3.9%/patient-year with and 5.0%/patient-year without anticoagulation (NOAH-AFNET 6), and 3.2%/patient-year with and 4.4%/patient-year without anticoagulation (ARTESiA). Without vascular disease, outcomes were equal with and without anticoagulation (NOAH-AFNET 6 2.7%/patient-year, ARTESiA 2.3%/patient-year in both randomised groups). Meta-analysis found consistent results across both trials (I2heterogeneity=6%) with a trend for interaction with randomised therapy (pinteraction=0.08). Stroke/SE behaved similarly. Anticoagulation increased major bleeding in vascular disease patients (edoxaban 2.1%/patient-year, no anticoagulation 1.3%/patient-year; apixaban 1.7%/patient-year; no anticoagulation 1.1%/patient-year; incidence rate ratio 1.55 [1.10-2.20]) and without vascular disease (edoxaban 2.2%/patient-year; no anticoagulation 0.6%/patient-year; apixaban 1.4%/patient-year; no anticoagulation 1.1%/patient-year, incidence rate ratio 1.93 [0.72-5.20]). CONCLUSIONS: Patients with DDAF and vascular disease are at higher risk of stroke and cardiovascular events and may derive a greater benefit from anticoagulation than patients with DDAF without vascular disease.

[Epicardial ablation of ventricular tachycardia with cardiac surgery only : Pro/Contra]. / Epikardiale Ablation ventrikulärer Tachykardien nur mit Herzchirurgie : Pro/Contra.

During the ablation of ventricular arrhythmias (VA) complications can occur, albeit rather rarely, and their occurrence depends on various factors. On the one hand the patient's condition and comorbidities play a role, on the other hand the access site and the procedure itself can lead to complications which have to be addressed adequately. This article will discuss whether complex ablations with epicardial access should only be performed at centres with the appropriate expertise and a cardiac surgery department.

The incidence of atrial fibrillation detected by implantable loop recorders: a comparison between patients with and without embolic stroke of undetermined source.

Aims: Stroke is the most debilitating outcome of atrial fibrillation (AF). The use of implantable loop recorders increases the detection of AF episodes among patients with embolic stroke of undetermined source. The significance of device-detected AF, or subclinical AF, is unknown. This study aimed to compare the incidence of AF detected by implantable loop recorder in patients with and without embolic stroke of undetermined source. Methods and results: We retrospectively studied all patients without known AF who were referred to our institution for implantable loop recorder implantation following embolic stroke of undetermined source, syncope, or palpitations from March 2009 to November 2019. The primary endpoint was any detection of AF or atrial flutter by implantable loop recorder. Seven hundred and fifty patients were included and followed up for a mean duration of 731 days (SD 443). An implantable loop recorder was implanted following embolic stroke of undetermined source in 323 and for assessment of syncope, palpitations, or another reason in 427 patients. The incidence of AF was significantly (P < 0.001) higher among patients with embolic stroke of undetermined source compared with the non-embolic stroke of undetermined source group; 48.6% vs. 13.8% (for any duration of AF) and 32.2% vs. 12.4% (for AF lasting ≥30 s) both P < 0.001. Kaplan-Meier analysis showed significantly higher incidence of AF for incremental durations of AF up to >5.5 h, but not >24 h. This was driven by longest AF durations of <6 min and between 5.5 h and 24 h, suggesting a bimodal distribution. In a multivariable Cox regression analysis, embolic stroke of undetermined source independently conferred an almost 5-fold increase in the hazard for any duration of AF. Conclusion: The incidence of AF is significantly higher amongst embolic stroke of undetermined source vs. non-embolic stroke of undetermined source patients monitored constantly by an implantable loop recorder. A high number of embolic stroke of undetermined source survivors have short-duration AF episodes. Further work is needed to determine the optimal treatment strategy of these AF episodes in embolic stroke of undetermined source.

Recent Advances in the Management of Non-rheumatic Atrial Fibrillation: A Comprehensive Review.

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia characterized by irregular atrial electrical activity, posing significant challenges to patient management and healthcare systems worldwide. Non-rheumatic AF, distinct from AF due to rheumatic heart disease, encompasses a spectrum of etiologies, including hypertension, coronary artery disease, and structural heart abnormalities. This review examines the latest advancements in managing non-rheumatic AF, encompassing diagnostic approaches, pharmacological therapies, and innovative non-pharmacological interventions. Diagnostic strategies ranging from traditional electrocardiography to advanced imaging modalities are explored alongside emerging biomarkers and wearable technologies facilitating early detection and management. Pharmacological management options, including novel anticoagulants and rhythm control agents, are evaluated in light of current guidelines and recent clinical trials. Non-pharmacological interventions, such as catheter ablation and device-based therapies, are discussed regarding their evolving techniques and outcomes. Special considerations for diverse patient populations, including elderly individuals and athletes, are addressed, emphasizing personalized approaches to optimize therapeutic outcomes. The review concludes with insights into future directions for AF management, highlighting promising avenues in gene therapy, regenerative medicine, and precision medicine approaches. By synthesizing recent research findings and clinical innovations, this review provides a comprehensive overview of the dynamic landscape of non-rheumatic AF management, offering insights for clinicians, researchers, and healthcare stakeholders.

Wearables are a viable digital health tool for older Indigenous adults living remotely in Australia (research).

Objective: Health programs for Indigenous people are most effective, acceptable, and sustainable when Indigenous perspectives are prioritized. Codesign builds on Indigenous people's creativity and propensity to experiment with new technologies and ensures research is designed and implemented in a culturally safe and respectful manner. Limited research has focused on older Indigenous people as partners in digital health. No research has focused on the acceptability and feasibility of older Indigenous people using wearables for heart health monitoring. This study provides insights into the acceptability and feasibility for ≥55-year-old Indigenous people living in remote locations to use wearables (watches and patches) to detect atrial fibrillation (AF) and high blood pressure. Methods: This mixed methods study was codesigned and coimplemented with the local Aboriginal Controlled Health Service in a remote area of New South Wales, Australia. It included active involvement and codesign with the participants. The devices used in this study included a Withings Scan watch and a Biobeat patch. Results: Despite challenging conditions (>36°C) and variable internet connectivity, 11 Indigenous older adults participated in a five-day wearables program in a remote location. Participants indicated that using digital health devices was acceptable and feasible for older Indigenous users. They described high levels of comfort, safety and convenience when using wearables (patches and watches) to detect AF. They were active participants in codesigning the program. Conclusion: Older Indigenous Australians are motivated to use wearable health devices. They are keen to participate in codesign innovative health tech programs to ensure new health technologies are acceptable to Indigenous people and feasible for remote locations.

Safety of dofetilide in stable patients and investigating traits of susceptibility to torsade de pointes.

Background: Atrial fibrillation is the most prevalent cardiac arrhythmia, presenting symptomatic patients with diminished quality of life and worsening of heart failure. Dofetilide, a class 3 antiarrhythmic agent, is a proven and safe rhythm control medication. Initial risk of QT prolongation leading to torsade de pointes (TdP) necessitates a standard protocol mandating hospitalization for three days for initiation. Objectives: To assess safety when adhering to initiation protocol and identify traits for susceptibility to TdP in elective dofetilide admissions. Methods: We conducted a retrospective study involving patients admitted to Mayo Clinic sites across four states for elective inpatient initiation of dofetilide between 2003 and 2022. Patients' charts underwent review, focusing on dofetilide-related TdP occurrences, baseline characteristics including QT intervals, laboratory values, comorbidities, and concomitant medications. Patients who experienced TdP were subjected to further evaluation to identify potential risk factors. Results: Of 2036 patients identified, mean age 66.4 ± 11.4 years, and 67.2 % male, 16 experienced dofetilide-related TdP (incidence rate 0.79%). Notably, 81% (13/16) of TdP cases occurred in patients who deviated from the FDA/manufacturer algorithm protocol. The concomitant use of active intravenous diuretic therapy, digoxin, and QT-prolonging drugs emerged as identifiable risk factors. Additionally, females exhibited a higher incidence of TdP (1.5%) than males (0.44%) {odd ratio [OR] 3.46; P = 0.017}. Conclusion: Overall incidence of TdP related to dofetilide initiation was low (0.79%). Adherence to protocol during elective hospital admissions appears extraordinarily safe. Patients who did not require concurrent use of intravenous diuretics, digoxin, or QT prolonging drugs exhibited lower risk of TdP.

Construction and validation of a risk prediction model for 3- and 5-year new-onset atrial fibrillation in HFpEF patients.

Background: Patients with heart failure (HF) with preserved ejection fraction (HFpEF) are more prone to atrial fibrillation (AF) compared to those with heart failure with reduced ejection fraction (HFrEF). Nevertheless, a risk prediction model for new-onset atrial fibrillation (NOAF) in HFpEF patients remains a notable gap, especially with respect to imaging indicators. Methods: We retrospectively analyzed 402 HFpEF subjects reviewed at the Affiliated Hospital of Qingdao University from 2017 to 2023. Cox regression analysis was performed to screen predictors of NOAF. A nomogram was constructed based on these factors and internally validated through the bootstrap resampling method. A performance comparison between the nomogram and the mC2HEST score was performed. Results: Out of the 402 participants, 62 (15%) developed atrial fibrillation. The risk factors for NOAF were finally screened out to include age, chronic obstructive pulmonary disease (COPD), hyperthyroidism, renal dysfunction, left atrial anterior-posterior diameter (LAD), and pulmonary artery systolic pressure (PASP), all of which were identified to create the nomogram. We calculated the bootstrap-corrected C-index (0.819, 95% CI: 0.762-0.870) and drew receiver operator characteristic (ROC) curves [3-year areas under curves (AUC) = 0.827, 5-year AUC = 0.825], calibration curves, and clinical decision curves to evaluate the discrimination, calibration, and clinical adaptability of the six-factor nomogram. Based on two cutoff values calculated by X-tile software, the moderate- and high-risk groups had more NOAF cases than the low-risk group (P < 0.0001). Our nomogram showed better 3- and 5-year NOAF predictive performance than the mC2HEST score estimated by the Integrated Discriminant Improvement Index (IDI) and the Net Reclassification Index (NRI) (P < 0.05). Conclusions: The nomogram combining clinical features with echocardiographic indices helps predict NOAF among HFpEF patients.

Identification of miR-1 and miR-499 in chronic atrial fibrillation by bioinformatics analysis and experimental validation.

Background: Atrial fibrillation (AF) is one of the most prevalent arrhythmias and is characterized by a high risk of heart failure and embolic stroke, yet its underlying mechanism is unclear. The primary goal of this study was to establish a miRNA-mRNA network and identify the miRNAs associated with chronic AF by bioinformatics and experimental validation. Methods: The GSE79768 dataset was collected from the Gene Expression Omnibus(GEO) database to extract data from patients with or without persistent AF. Differentially expressed genes (DEGs) were identified in left atrial appendages (LAAs). The STRING platform was utilized for protein-protein interaction (PPI) network analysis. The target miRNAs for the top 20 hub genes were predicted by using the miRTarBase Web tool. The miRNA-mRNA network was established and visualized using Cytoscape software. The key miRNAs selected for verification in the animal experiment were confirmed by miRwalk Web tool. We used a classic animal model of rapid ventricular pacing for chronic AF. Two groups of animals were included in the experiment, namely, the ventricular pacing group (VP group), where ventricular pacing was maintained at 240-280 bpm for 2 weeks, and the control group was the sham-operated group (SO group). Finally, we performed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to validate the expression of miR-1 and miR-499 in LAA tissues of the VP group and the SO group. Left atrial fibrosis and apoptosis were evaluated by Masson staining and caspase-3 activity assays, respectively. Results: The networks showed 48 miRNAs in LAA tissues. MiR-1 and miR-499 were validated using an animal model of chronic AF. The expression level of miR-1 was increased, and miR-499 was decreased in VP group tissues compared to SO group tissues in LAAs (P < 0.05), which were correlated with left atrial fibrosis and apoptosis in AF. Conclusion: This study provides a better understanding of the alterations in miRNA-1 and miR-499 in chronic AF from the perspective of the miRNA-mRNA network and corroborates findings through experimental validation. These findings may offer novel potential therapeutic targets for AF in the future.

Left atrial deformation analysis in patients with non-ischaemic dilated cardiomyopathy in atrial fibrillation.

Aims: Atrial fibrillation (AF) is a common comorbidity in non-ischaemic dilated cardiomyopathy (NIDCM) affecting conventional measures of left atrial (LA) function. We aimed to determine whether LA function analysis could identify patients at higher risk of major cardiovascular events (MACEs). Methods and results: A retrospective study of patients with NIDCM in AF referred to a single centre for transthoracic echocardiography (TTE) between 2015 and 2019. Peak atrial longitudinal strain (PALS) was measured along with LA emptying fraction and LA filling index (LAFI = E wave/PALS). Cox regression analysis was conducted. A total of 153 patients were included [median age 74 years, left ventricular ejection fraction (LVEF) 35%], and 57 (37.3%) had MACE after a median follow-up of 3.2 years. LAFI was the only independent TTE parameter associated with MACE after adjustment for age, diabetes, LVEF, left ventricular global longitudinal strain (LV-GLS), and LA volume index [adjusted hazard ratio (HR) = 1.02 per point increase, P = 0.024], with the best cut-off at ≥15. LAFI ≥15 predicted each of MACE components when separately analysed: MACE HR = 1.95, 95% confidence interval (CI) 1.16-3.30; cardiovascular death HR = 3.68, 95% CI 1.41-9.56, heart failure admission HR = 2.13, 95% CI 1.19-3.80, and ventricular arrhythmia HR = 4.72, 95% CI 1.52-14.67. Higher LAFI was associated with worsening LV-GLS, E/e', systolic pulmonary artery (PA) pressure, tricuspid annular plane systolic excursion, and right ventricular to PA coupling. Conclusion: LA deformation analysis is feasible in patients with NIDCM presenting with AF. LAFI may identify patients at higher risk of MACE and correlates with higher pulmonary pressures and worse right ventricular function, suggesting an elevation of left-sided ventricular pressures in patients with higher LAFI.

DACT2 modulates atrial fibrillation through TGF/ß and Wnt signaling pathways.

Atrial fibrillation (AF) is a common cardiac arrhythmia that seriously affects the quality of life of patients. Effective treatment and prevention are important to control the morbidity and mortality of AF. It has been found that cardiac fibrosis promotes the onset and progression of AF. It is now known that transforming growth factor ß (TGF-ß), an important fibrotic cytokine, plays an important role in cardiac fibrosis by inducing myofibroblast activation via the activation of classical (SMAD-based) and non-classical (non-SMAD-based) signaling pathways. In addition, specific activation of the Wnt/ß-catenin pathway has been shown to promote the transformation of fibroblasts into myofibroblasts. In recent years, a new family of proteins, namely Disheveled-associated antagonist of beta-catenin (DACT) 2, can affect the Wnt/ß-catenin and TGF-ß signaling pathways by regulating the phosphorylation levels of these target proteins, which in turn affects the progression of fibrosis. The present study focuses on the effect of DACT2-guided ß-catenin on atrial fibrosis. It is expected that the summarized information can be helpful in the treatment of AF.

Ocular blood flow dynamics following sinus rhythm restoration through catheter ablation: laser speckle flowgraphy in patients with persistent atrial fibrillation.

Aims: Laser speckle flowgraphy (LSFG) is a well-established tool renowned for its non-invasive and reproducible assessment of ocular blood flow. While rhythm control therapies, such as catheter ablation (CA), have shown promise in enhancing cognitive function in atrial fibrillation (AF) patients, the acute impact of CA on microcirculatory changes, particularly in ocular blood flow, remains a topic of limited understanding. The present study aims to delve into the potential of LSFG in detecting microcirculatory alterations following the restoration of sinus rhythm (SR) through CA in patients with AF. Methods and results: We studied 8 paroxysmal AF (Paf) and 20 persistent AF (PeAF) patients (mean age 67 ± 6 years, 26% female) undergoing CA. Ocular blood flow was assessed using LSFG by measuring the mean blur rate (MBR) pre- and post-CA. Post-CA, all PeAF patients achieved SR restoration, resulting in a significant increase in tissue MBR (10.0 ± 2.2 to 10.8 ± 2.9, P = 0.021). In contrast, Paf patients showed no significant difference between pre- and post-MBR (12.0 ± 2.7 vs. 11.8 ± 2.6, P = 0.76). Conclusion: LSFG analysis effectively identified microcirculatory changes in patients undergoing CA for PeAF, suggesting that therapeutic interventions targeting the heart may have broader implications for ocular and cerebral health, establishing a novel 'cardio-oculo-cerebral relationship'.

Left atrial function in patients with rheumatic mitral stenosis: addressing prognostic insights beyond atrial fibrillation prediction.

Aims: Rheumatic mitral stenosis (MS) frequently leads to impaired left atrial (LA) function because of pressure overload, highlighting the underlying atrial pathology. Two-dimensional speckle tracking echocardiography (2D-STE) offers early detection of LA dysfunction, potentially improving risk assessment in patients with MS. This study aims to evaluate the predictive value of LA function assessed by 2D-STE for clinical outcomes in patients with MS. Methods and results: Between 2011 and 2021, patients with MS underwent LA function assessment using 2D-STE, with focus on the reservoir phase (LASr). Atrial fibrillation (AF) development constituted the primary outcome, with death or valve replacement as the secondary outcome. Conditional inference trees were employed for analysis, validated through sample splitting. The study included 493 patients with MS (mean valve area 1.1 ± 0.4 cm2, 84% female). At baseline, 166 patients (34%) had AF, with 62 patients (19%) developing AF during follow-up. LASr emerged as the primary predictor for new-onset AF, with a threshold of 17.9%. Over a mean 3.8-year follow-up, 125 patients (25%) underwent mitral valve replacement, and 32 patients (6.5%) died. A decision tree analysis identified key predictors such as age, LASr, severity of tricuspid regurgitation (TR), net atrioventricular compliance (C n), and early percutaneous mitral valvuloplasty, especially in patients aged ≤49 years, where LASr, with a threshold of 12.8%, significantly predicted adverse outcomes. Conclusion: LASr emerged as a significant predictor of cardiovascular events in this MS cohort, validated through a decision tree analysis. Patients were stratified into low- or high-risk categories for adverse outcomes, taking into account LASr, age, TR severity, and C n.

Successful Treatment of a Patient with Hepatic Portal Vein Gas after Radiofrequency Ablation of Atrial Fibrillation: A Case Report.

BACKGROUND: Transcatheter radiofrequency ablation is one of the main treatments for atrial fibrillation, but related complications of this surgery are uncommon. CASE PRESENTATION: Here, we report a 70-year-old elderly male patient with atrial fibrillation who experienced severe abdominal pain early after undergoing radiofrequency ablation; related imaging examinations suggested that the patient had intestinal edema and thickening, combined with hepatic portal vein gas accumulation. The reason was that the patient experienced intestinal necrosis due to superior mesenteric artery embolism related to radiofrequency surgery. The surgeon suggested laparotomy for exploration. However, after multidisciplinary consideration, we ultimately chose conservative treatment. After fasting, gastrointestinal decompression, spasmolysis, pain relief, somatostatin inhibition of intestinal edema, antiinfection, and anticoagulation, the patient's condition improved, and he was discharged. We followed the patient for 1 month after discharge, and there was no special discomfort. CONCLUSION: Hepatoportal vein gas accumulation after radiofrequency ablation of atrial fibrillation is rare, and imaging findings have important guiding significance for the diagnosis and treatment of the disease.