Identification of common mechanisms and biomarkers of atrial fibrillation and heart failure based on machine learning.

AIMS: Atrial fibrillation (AF) is the most common arrhythmia. Heart failure (HF) is a disease caused by heart dysfunction. The prevalence of AF and HF were progressively increasing over time. The co-existence of AF and HF presents a significant therapeutic challenge. In order to provide new ideas for the diagnosis of AF and HF, it is necessary to carry out biomarker related studies. METHODS AND RESULTS: The training set and validation set data of AF and HF patient samples were downloaded from the GEO database, 'limma' was used to compare the differences in gene expression levels between the disease group and the normal group to screen for differentially expressed genes (DEGs). Weighted correlation network analysis (WGCNA) identified the modules with the highest positive correlation with AF and HF. Functional enrichment and PPI network construction of key genes were carried out. Biomarkers were screened by machine learning. The infiltration of immune cells in AF and HF groups was evaluated by R-packet 'CIBERSORT'. The miRNA network was constructed and potential therapeutic agents for biomarker genes were predicted through the drugbank database. Through WGCNA analysis, it was found that the modules most positively correlated with AF and HF were MEturquoise (r = 0.21, P value = 0.09) and MEbrown (r = 0.62, P value = 8e-12), respectively. We screened 25 genes that were highly correlated with both AF and HF. Lasso regression analysis results showed 7 and 20 core genes in AF and HF groups, respectively. The top 20 important genes in AF and HF groups were obtained as core genes by RF model analysis. Four biomarkers were obtained after the intersection of core genes in four groups, namely, GLUL, NCF2, S100A12, and SRGN. The diagnostic efficacy of four genes in AF validation sets was good (AUC: GLUL 0.76, NCF2 0.64, S100A12 0.68, and SRGN 0.76), as well as in the HF validation set (AUC: GLUL 0.76, NCF2 0.84, S100A12 0.92, and SRGN 0.68). The highest correlation with neutrophils was observed for GLUL, NCF2, and S100A12, while SRGN exhibited the strongest correlation with T cells CD4 memory resting in the AF group. GLUL, NCF2, S100A12, and SRGN were most associated with neutrophils in the HF group. A total of 101 miRNAs were predicted by four genes, and GLUL, NCF2, and S100A12 predicted a total of 10 potential therapeutic agents. CONCLUSIONS: We identified four biological markers that are highly correlated with AF and HF, namely, GLUL, NCF2, S100A12, and SRGN. Our findings provide theoretical basis for the clinical diagnosis and treatment of AF and HF.

Clinical Impact of Early Rhythm Control and Healthy Lifestyles in Patients With Atrial Fibrillation.

BACKGROUND: There are limited data regarding the combined effect of early rhythm control (ERC) and healthy lifestyle (HLS) behaviors on the risk of ischemic stroke in patients with atrial fibrillation (AF). OBJECTIVES: This study sought to evaluate how the combination of ERC and HLS behaviors affects the risk of ischemic stroke in patients with AF. METHODS: Using the Korean National Health Insurance database, we included patients with new-onset AF between 2009 and 2016 (n = 208,662). Patients who received rhythm control therapy within 2 years after AF diagnosis were defined as the ERC group. Patients with ≥2 HLS behaviors were defined as the HLS group. Patients were categorized into 4 groups: group 1, without ERC and without HLS (n = 46,972); group 2, with HLS alone (n = 110,479); group 3, with ERC alone (n = 15,133); and group 4, with both ERC and HLS (n = 36,078). The primary outcome was ischemic stroke. RESULTS: Compared to group 1, group 2 and group 3 were associated with a lower risk of stroke (HR: 0.769 [95% CI: 0.728-0.881] and HR: 0.774 [95% CI: 0.703-0.852], respectively). Group 4 showed the lowest risk of stroke (HR: 0.575; 95% CI: 0.536-0.617). After propensity score weighting, the incorporation of additional ERC alongside HLS was associated with a relative risk reduction of 22% for stroke, and additional HLS alongside ERC were associated with a relative risk reduction of 27% for stroke. CONCLUSIONS: Each of ERC and HLS might reduce the risk of ischemic stroke in patients with new-onset AF. The presence of both ERC and HLS is associated with an enhanced benefit for stroke prevention in this population.

Efficacy and Safety of Botulinum Toxin Type A for the Prevention of Postoperative Atrial Fibrillation.

BACKGROUND: Postoperative atrial fibrillation (POAF) is associated with increased morbidity and mortality. Epicardial injection of botulinum toxin may suppress POAF. OBJECTIVES: This study sought to assess the safety and efficacy of AGN-151607 for the prevention of POAF after cardiac surgery. METHODS: This phase 2, randomized, placebo-controlled trial assessed the safety and efficacy of AGN-151607, 125 U and 250 U vs placebo (1:1:1), for the prevention of POAF after cardiac surgery. Randomization was stratified by age (<65, ≥65 years) and type of surgery (nonvalvular/valve surgery). The primary endpoint was the occurrence of continuous AF ≥30 seconds. RESULTS: Among 312 modified intention-to-treat participants (placebo, n = 102; 125 U, n = 104; and 250 U, n = 106), the mean age was 66.9 ± 6.8 years; 17% were female; and 64% had coronary artery bypass graft (CABG) only, 12% had CABG + valve, and 24% had valve surgery. The primary endpoint occurred in 46.1% of the placebo group, 36.5% of the 125-U group (relative risk [RR] vs placebo: 0.80; 95% CI: 0.58-1.10; P = 0.16), and 47.2% of the 250-U group (RR vs placebo: 1.04; 95% CI: 0.79-1.37; P = 0.78). The primary endpoint was reduced in the 125-U group in those ≥65 years (RR: 0.64; 95% CI: 0.43-0.94; P = 0.02) with a greater reduction in CABG-only participants ≥65 years (RR: 0.49; 95% CI: 0.27-0.87; P = 0.01). Rehospitalization and rates of adverse events were similar across the 3 groups. CONCLUSIONS: There were no significant differences in the rate of POAF with either dose compared with placebo; however, there was a lower rate of POAF in participants ≥65 years undergoing CABG only and receiving 125 U of AGN-151607. These hypothesis-generating findings require investigation in a larger, adequately powered randomized clinical trial. (Botulinum Toxin Type A [AGN-151607] for the Prevention of Post-operative Atrial Fibrillation in Adult Participants Undergoing Open-chest Cardiac Surgery [NOVA]; NCT03779841); A Phase 2, Multi-Center, Randomized, Double-Blind, Placebo-Controlled, Dose Ranging Study to Evaluate the Efficacy and Safety of Botulinum Toxin Type A [AGN 151607] Injections into the Epicardial Fat Pads to Prevent Post-Operative Atrial Fibrillation in Patients Undergoing Open-Chest Cardiac Surgery; 2017-004399-68).

Analysis of the Effectiveness of the Latest 4th Generation Cryoballoon Catheters in Pulmonary Vein Isolation Using High-Resolution Mapping.

BACKGROUND: Long-term data showed that up to 27% of pulmonary veins are reconnected using cryoballoon ablation. This study aims to evaluate the efficacy of the latest 4th generation cryoballoon catheters using ultra high-resolution mapping. METHODS: In patients with AF, a standard PVI with the latest 4th generation cryoballoon catheter (Arctic Front Advance PRO, Medtronic Minneapolis, USA) and the spiral mapping catheter (Achieve Advance, Medtronic, Minneapolis, MN, USA) was performed. Subsequently, high-resolution mapping was achieved using the novel multipolar grid mapping catheter (Advisor HD Grid SE, Abbott Laboratories; USA). Follow-up was obtained after 6 months by means of a 7-day Holter ECG. RESULTS: In our study, acute PVI was successfully achieved in all 31 patients. The latest 4th generation cryoballoon catheter is safe in the acute phase of PVI. Additional high-resolution mapping (mean points per map 21001 ± 4911) using the multipolar grid mapping catheter enabled us to identify residual gaps only in the carina PV region; therefore, no additional ablation was performed. Three out of 31 patients (10%) presented with atrial arrhythmia recurrence always related with PV reconnection; using high-resolution mapping had no additional benefit in identifying pulmonary veins in which reconnection will occur. CONCLUSION: The utility of additional high-density mapping, facilitated by the HD Grid catheter following PVI with the fourth-generation cryoballoon catheter do not substantiate a discernible advantage over conventional mapping methodologies, particularly the spiral mapping catheter. Residual carinal conduction was observed in a substantial cohort of patients (48%), highlighting a persistent challenge in achieving complete electrical isolation.

Predictors of atrial fibrillation after embolic stroke of undetermined source in patients with implantable loop recorders.

BACKGROUND: In patients with embolic stroke of undetermined source (ESUS), underlying subclinical atrial fibrillation (AF) is often suspected. Previous studies identifying predictors of AF have been limited in their ability to diagnose episodes of AF. Implantable loop recorders enable prolonged, continuous, and therefore more reliable detection of AF. The aim of this study was to identify clinical and ECG parameters as predictors of AF in ESUS patients with implantable loop recorders. METHODS: 101 ESUS patients who received an implantable loop recorder between 2012 and 2020 were included in this study. Patients were followed up regularly on a three-monthly outpatient interval. RESULTS: During a mean follow-up of 647 ± 385 days, AF was detected in 26 patients (26%). Independent risk factors of AF were age ≥ 60 years (HR 2.753, CI 1.129-6.713, p = 0.026), P-wave amplitude in lead II ≤ 0.075 mV (HR 3.751, CI 1.606-8.761, p = 0.002), and P-wave duration ≥ 125 ms (HR 4.299, CI 1.844-10.021, p < 0.001). In patients without risk factors, the risk of developing AF was 16%. In the presence of one risk factor, the probability increased only slightly to 18%. With two or three risk factors, the risk of AF increased to 70%. CONCLUSION: AF was detected in about one in four patients after ESUS in this study. A comprehensive evaluation involving multiple parameters and the existence of multiple risk factors yields the highest predictive accuracy for detecting AF in patients with ESUS.

Adjunctive low-voltage area ablation for patients with atrial fibrillation: An updated meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of adjunctive low-voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain. METHODS: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses. RESULTS: Our meta-analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67-0.88; p < .01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35-0.85; p < .01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38-0.86; p < .01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39-1.56; p = .49). CONCLUSIONS: Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF.

Comparison between beta-blockers and calcium channel blockers in patients with atrial fibrillation according to renal function.

BACKGROUND: Rate control is the most commonly employed first-line management strategy for atrial fibrillation (AF) in patients with chronic kidney disease (CKD). Principal agents used to control heart rate (HR) include beta-blockers (BB) and nondihydropyridine calcium channel blockers (ND-CCB). However, there is a paucity of published studies of the differences between those drugs in CKD patients. HYPOTHESIS: The present study aimed to investigate the differences, in terms of hospitalizations due to a poor HR control, in patients with AF under a rate-control strategy according to glomerular filtration rate (GFR). METHODS: The study cohort included 2804 AF patients under rate-control regime (BB or ND-CCB) between January 2014 and April 2020. The end point, determined by competing risk regression, was hospitalizations for AF with rapid ventricular response (RVR), slow ventricular response (SVR), and need for pacemaker. RESULTS: On multivariate analysis, there were no statistical differences between ND-CCB and BB for subjects with GFR > 60 mL/min/1.73 m2 (subdistribution heart rate [sHR] 0.850, 95% confidence interval [CI]: 0.61-1.19; p = .442) and GFR 30-59 mL/min/1.73 m2 (sHR 1.242, 95% CI: 0.80-1.63; p = .333), while in patients with GFR < 30 mL/min/1.73 m2, ND-CCB therapy was associated with increased hospitalizations due to poor HR control (sHR 4.53, 95% CI: 1.19-17.18; p = .026). CONCLUSION: In patients with GFR ≥ 30 mL/min/1.73 m2, the choice of ND-CCB or BB had no impact on hospitalizations due to poor HR control, while in GFR < 30 mL/min/1.73 m2, a possible association was detected. The effects of these drugs on GFR < 30 mL/min/1.73 m2 would require further investigation.

A causal association between amyotrophic lateral sclerosis and atrial fibrillation: a two-sample Mendelian randomization study.

Objectives: To look into the connection between amyotrophic lateral sclerosis (ALS) and atrial fibrillation (AF) using Mendelian randomization (MR). Methods: Two-sample MR was performed using genetic information from genome-wide association studies (GWAS). Genetic variants robustly associated with ALS and AF were used as instrumental variables. GWAS genetic data for ALS (n = 138,086, ncase = 27,205) and AF (n = 1,030,836, ncase = 60,620), publicly available from IEU Open. The specific MR protocols were Inverse variance-weighted (IVW), Simple mode, MR Egger, Weighted mode, and Weight median estimator (WME). Subsequently, the MR-Egger intercept and Cochran Q examine were used to evaluate instrumental variables (IVs)' heterogeneity and multiplicative effects (IVs). In addition, MR-PRESSO analysis was conducted to exclude any potential pleiotropy. Results: The IVW method demonstrated that ALS positively affected AF [OR: 1.062, 95% CI (1.004-1.122); P = 0.035]. Indeed, other MR methods were in accordance with the tendency of the IVW method (all OR > 1), and sensitivity testing verified the reliability of this MR result. Conclusions: This MR study proves a positive causal connection between ALS and atrial fibrillation. Further studies are warranted to elucidate the mechanisms linking ALS and AF.

Disordered GPR43/NLRP3 expression in peripheral leukocytes of patients with atrial fibrillation is associated with intestinal short chain fatty acids levels.

BACKGROUND: Atrial fibrillation (AF) is associated with circulating inflammation. Short-chain fatty acids (SCFAs) derived from gut microbiota (GM) regulate leukocyte function and inhibit the release of inflammatory cytokines, which are partly mediated by the G-protein-coupled receptor 43 (GPR43) signaling. This study aimed to investigate the expression of GPR43/NOD-like receptors family pyrin domain containing 3 (NLRP3) in leukocytes and the interaction with intestinal SCFAs levels in AF patients. METHODS: Expressions of GPR43 and NLRP3 mRNA in peripheral blood leukocytes from 23 AF patients and 25 non-AF controls were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Expressions of leukocyte GPR43 and NLRP3 protein were evaluated by western blot analysis. The levels of plasma IL-1ß were measured by enzyme-linked immunosorbent assay (ELISA). The fecal SCFAs levels based on GC/MS metabolome of corresponding 21 controls and 14 AF patients were acquired from our published dataset. To evaluate the expression of NLRP3 and GPR43 and the release of IL-1ß, human THP-1 cells were stimulated with or without SCFAs (acetate, propionate, and butyrate), lipopolysaccharide (LPS), and nigericin in vitro, respectively. RESULTS: Compared to the controls, the mRNA expression in peripheral leukocytes was significantly reduced in AF patients (P = 0.011) coupled with the increase in downstream leukocyte NLRP3 mRNA expression (P = 0.007) and plasma IL-1ß levels (P < 0.001), consistent with changes in GPR43 and NLRP3 protein expression. Furthermore, leukocyte GPR43 mRNA levels were positively correlated with fecal GM-derived acetic acid (P = 0.046) and negatively correlated with NLRP3 mRNA expression (P = 0.024). In contrast to the negative correlation between left atrial diameter (LAD) and GPR43 (P = 0.008), LAD was positively correlated with the leukocyte NLRP3 mRNA levels (P = 0.024). Subsequent mediation analysis showed that 68.88% of the total effect of intestinal acetic acid on AF might be mediated by leukocyte GPR43/NLRP3. The constructed GPR43-NLRP3 score might have a predictive potential for AF detection (AUC = 0.81, P < 0.001). Moreover, SCFAs treatment increased GPR43 expression and remarkably reduced LPS/nigericin-induced NLRP3 expression and IL-1ß release in human THP-1 cells in vitro. CONCLUSIONS: Disrupted interactions between GPR43 and NLRP3 expression in peripheral blood leukocytes, associated with reduced intestinal GM-derived SCFAs, especially acetic acid, may be involved in AF development and left atrial enlargement by enhancing circulating inflammation.

Left atrial appendage closure in conjunction with radiofrequency ablation: Effects on left atrial functioning in patients with paroxysmal atrial fibrillation.

Objective: In the present study, we investigated the impact of left atrial appendage closure (LAAC) following catheter ablation (CA) on the left atrial structure and functioning of patients with paroxysmal atrial fibrillation (AF). Methods: Patients with paroxysmal AF were enrolled in this single-center prospective cohort study between April 2015 and July 2021; 353 patients received CA alone, while 93 patients received CA in combination with Watchman LAAC. We used age, gender, CHA2DS2-VASc, and HAS-BLED scores as well as other demographic variables to perform propensity score matching. Patients with paroxysmal AF were randomly assigned to the CA combined with Watchman LAAC group (combined treatment group) and the simple CA group, with 89 patients in each group. The left atrial structure, reserve, ventricular diastole, and pump functions and their changes in patients were assessed using routine Doppler echocardiography and 2D speckle tracking echocardiography over the course of a 1-year follow-up. Results: At 1-week follow-up, the reserve, ventricular diastole, and pump functions of the left atrium (LA) increased in both groups; these functions were gradually restored at the 1- to 3-month follow-up; they were close to or returned to their pre-operative levels at the 3-month follow-up; and no significant differences were found compared with the pre-operative levels at the 12-month follow-up. In the first 3 months, the reserve (Ƹ, SRs) and pump functions (SRa) in the combined treatment group decreased significantly when compared with the simple CA group, and the differences were statistically significant. Conclusion: Patients with paroxysmal AF may experience a short term, partial effect of LAAC on LA reserve and pump functions, which are gradually restored and the effect disappears by 12 months.

Analyses of lncRNA and mRNA profiles in recurrent atrial fibrillation after catheter ablation.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Catheter ablation has become a crucial treatment for AF. However, there is a possibility of atrial fibrillation recurrence after catheter ablation. Our study sought to elucidate the role of lncRNA‒mRNA regulatory networks in late AF recurrence after catheter ablation. METHODS: We conducted RNA sequencing to profile the transcriptomes of 5 samples from the presence of recurrence after AF ablation (P-RAF) and 5 samples from the absence of recurrence after AF ablation (A-RAF). Differentially expressed genes (DEGs) and long noncoding RNAs (DE-lncRNAs) were analyzed using the DESeq2 R package. The functional correlations of the DEGs were assessed through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. A protein‒protein interaction (PPI) network was constructed using STRING and Cytoscape. We also established a lncRNA‒mRNA regulatory network between DE-lncRNAs and DEGs using BEDTools v2.1.2 software and the Pearson correlation coefficient method. To validate the high-throughput sequencing results of the hub genes, we conducted quantitative real-time polymerase chain reaction (qRT‒PCR) experiments. RESULTS: A total of 28,528 mRNAs and 42,333 lncRNAs were detected. A total of 96 DEGs and 203 DE-lncRNAs were identified between the two groups. GO analysis revealed that the DEGs were enriched in the biological processes (BPs) of "regulation of immune response" and "regulation of immune system process", the cellular components (CCs) of "extracellular matrix" and "cell‒cell junction", and the molecular functions (MFs) of "signaling adaptor activity" and "protein-macromolecule adaptor activity". According to the KEGG analysis, the DEGs were associated with the "PI3K-Akt signaling pathway" and "MAPK signaling pathway." Nine hub genes (MMP9, IGF2, FGFR1, HSPG2, GZMB, PEG10, GNLY, COL6A1, and KCNE3) were identified through the PPI network. lncRNA-TMEM51-AS1-201 was identified as a core regulator in the lncRNA‒mRNA regulatory network, suggesting its potential impact on the recurrence of AF after catheter ablation through the regulation of COL6A1, FGFR1, HSPG2, and IGF2. CONCLUSIONS: The recurrence of atrial fibrillation after catheter ablation may be associated with immune responses and fibrosis, with the extracellular matrix playing a crucial role. TMEM51-AS1-201 has been identified as a potential key target for AF recurrence after catheter ablation.

Prognosis of patients in end-stage heart failure with atrial fibrillation treated with ablation: Insights from CASTLE-HTx.

BACKGROUND: The CASTLE-HTx trial demonstrated the benefit of atrial fibrillation (AF) ablation compared with medical therapy in decreasing mortality, need for left ventricular assist device implantation, or heart transplantation (HTx) in patients with end-stage heart failure (HF). OBJECTIVE: This analysis aimed to identify risk factors related to adverse outcomes in patients with end-stage HF and to assess the impact of ablation. METHODS: The CASTLE-HTx protocol randomized 194 patients with end-stage HF and AF to ablation vs medical therapy. We identified left ventricular ejection fraction <30%, New York Heart Association class ≥III, and AF burden >50% as predictors for the primary end point. The CASTLE-HTx risk score assigned weights to these risk factors. Patients with a risk score ≥3 were identified as high risk. RESULTS: The patients were assigned to low-risk (89 [45.9%]) and high-risk (105 [54.1%]) groups. After a median follow-up of 18 months, a primary end point event occurred in 6 and 31 patients of the low- and high-risk groups (hazard ratio, 4.98; 95% confidence interval, 2.08-11.9). The incidence rate (IR) difference between ablation and medical therapy was much larger in high-risk patients (8/49 [IR, 11.4] vs 23/56 [IR, 36.1]) compared with low-risk patients (2/48 [IR, 2.6] vs 4/41 [IR, 6.3]). The IR difference for ablation was significantly higher in high-risk patients (24.69) compared with low-risk patients (3.70). CONCLUSION: The absolute benefit of ablation is more pronounced in high-risk patients, but low-risk patients may also benefit. The CASTLE-HTx risk score identifies patients with end-stage HF who will particularly benefit from ablation.

Design of the Dutch multicentre study on opportunistic screening of geriatric patients for atrial fibrillation using a smartphone PPG app: the Dutch-GERAF study.

BACKGROUND: Screening of high-risk patients is advocated to achieve early detection and treatment of clinical atrial fibrillation (AF). The Dutch-GERAF study will address two major issues. Firstly, the effectiveness and feasibility of an opportunistic screening strategy for clinical AF will be assessed in frail older patients and, secondly, observational data will be gathered regarding the efficacy and safety of oral anticoagulation (OAC). METHODS: This is a multicentre study on opportunistic screening of geriatric patients for clinical AF using a smartphone photoplethysmography (PPG) application. Inclusion criteria are age ≥ 65 years and the ability to perform at least three PPG recordings within 6 months. Exclusion criteria are the presence of a cardiac implantable device, advanced dementia or a severe tremor. The PPG application records patients' pulse at their fingertip and determines the likelihood of clinical AF. If clinical AF is suspected after a positive PPG recording, a confirmatory electrocardiogram is performed. Patients undergo a comprehensive geriatric assessment and a frailty index is calculated. Risk scores for major bleeding (MB) are applied. Standard laboratory testing and additional laboratory analyses are performed to determine the ABC-bleeding risk score. Follow-up data will be collected at 6 months, 12 months and 3 years on the incidence of AF, MB, hospitalisation, stroke, progression of cognitive disorders and mortality. DISCUSSION: The Dutch-GERAF study will focus on frail older patients, who are underrepresented in randomised clinical trials. It will provide insight into the effectiveness of screening for clinical AF and the efficacy and safety of OAC in this high-risk population. TRIAL REGISTRATION: NCT05337202.

Automated identification of atrial fibrillation from single-lead ECGs using multi-branching ResNet.

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia, which is clinically identified with irregular and rapid heartbeat rhythm. AF puts a patient at risk of forming blood clots, which can eventually lead to heart failure, stroke, or even sudden death. Electrocardiography (ECG), which involves acquiring bioelectrical signals from the body surface to reflect heart activity, is a standard procedure for detecting AF. However, the occurrence of AF is often intermittent, costing a significant amount of time and effort from medical doctors to identify AF episodes. Moreover, human error is inevitable, as even experienced medical professionals can overlook or misinterpret subtle signs of AF. As such, it is of critical importance to develop an advanced analytical model that can automatically interpret ECG signals and provide decision support for AF diagnostics. Methods: In this paper, we propose an innovative deep-learning method for automated AF identification using single-lead ECGs. We first extract time-frequency features from ECG signals using continuous wavelet transform (CWT). Second, the convolutional neural networks enhanced with residual learning (ReNet) are employed as the functional approximator to interpret the time-frequency features extracted by CWT. Third, we propose to incorporate a multi-branching structure into the ResNet to address the issue of class imbalance, where normal ECGs significantly outnumber instances of AF in ECG datasets. Results and Discussion: We evaluate the proposed Multi-branching Resnet with CWT (CWT-MB-Resnet) with two ECG datasets, i.e., PhysioNet/CinC challenge 2017 and ECGs obtained from the University of Oklahoma Health Sciences Center (OUHSC). The proposed CWT-MB-Resnet demonstrates robust prediction performance, achieving an F1 score of 0.8865 for the PhysioNet dataset and 0.7369 for the OUHSC dataset. The experimental results signify the model's superior capability in balancing precision and recall, which is a desired attribute for ensuring reliable medical diagnoses.

Anti-Xa Monitoring of Apixaban (ZyQuis) in Venous Thrombo-Embolism and Atrial Fibrillation.

Apixaban is a direct oral Xa inhibitor and is indicated for the treatment of venous thrombo-embolism (VTE) and prevention of stroke in atrial fibrillation (AF). Recently, a generic (ZyQuis, Zydus Lifesciences Limited, India) has received Food and Drug Administration approval. While bioequivalence has been demonstrated with Eliquis (Bristol-Myers Squibb/Pfizer, UK), it is necessary to monitor its effectiveness prior to acceptance in medical practice. This prospective study independently evaluated Apixaban (ZyQuis) at two accredited laboratories. Participants were converted from Warfarin or Rivaroxaban to Apixaban 5 mg bd for a duration of one month. Peak anti-Xa levels were measured 3-4 h post the morning dose. The samples were processed on the Atellica COAG 360 (Siemens Healthineers, Marburg, Germany) analyzers with a chromogenic anti-Xa assay (Innovance, reference interval 69-321 ng/mL). There were 26 participants; 5 men, 21 women; mean ± standard deviation age of 46 ± 12 years. Indications for anticoagulation included: VTE (88.5%) and AF (11.5%). 69.2% of the participants had at least one comorbidity. 96.2% of the anti-Xa levels were within the laboratory's 95% reference interval. Mean anti-Xa activity was 191 ± 69 ng/mL and 186 ± 68 ng/mL measured at respective laboratories. Mean differences in anti-Xa measurements represented by Bland-Altman statistics were small (bias of -2.6%, 95% confidence interval -1.11 to -4.09) and a strong correlation was observed on Deming regression analysis (0.995). Apixaban (ZyQuis) was effective for the management of VTE and AF as evidenced by anti-Xa activity.

Knowledge, attitude, and practice of atrial fibrillation in high altitude areas.

Background: To investigate the knowledge, attitude, and practice (KAP) of atrial fibrillation (AF) among the general population in high-altitude areas. Methodology: A web-based cross-sectional study was conducted among the general population in high-altitude areas. Results: A total of 786 valid questionnaires were enrolled, with a mean age of 34.75 ± 14.16 years. The mean score of knowledge, attitude and practice were 8.22 ± 6.50 (possible range: 0-10), 28.90 ± 5.63 (possible range: 8-40), 34.34 ± 6.44 (possible range: 9-45), respectively. The multivariate analysis showed that knowledge scores (OR = 1.108, 95% CI = 1.075-1.142, p < 0.001), attitude scores (OR = 1.118, 95% CI = 1.081-1.156, p < 0.001), and never smoking (OR = 2.438, 95% CI = 1.426-4.167, p = 0.001) were independently associated with proactive practice. The structural equation modeling (SEM) showed direct effect of knowledge on practice (p = 0.014), and attitude on practice (p = 0.004), while no effect of knowledge on attitude (p = 0.190). Conclusion: The general population in high-altitude regions had adequate knowledge, positive attitude, and proactive practice towards AF. The SEM was suitable for explaining general population' KAP regarding AF, revealing that knowledge directly and positively affected attitude and practice.

Cancer and arterial thrombosis: therapeutic options.

A State of the Art lecture titled "Cancer and Arterial Thrombosis: Therapeutic Options" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. This State of the Art review delves into the complex relationship between cancer and arterial thromboembolism (ATE), encompassing acute coronary syndrome, ischemic strokes, and peripheral arterial disease. The burden of cancer-associated ATE is not well defined, but studies indicate elevated risks, particularly in the 6 months after a cancer diagnosis. Incidence varies among cancer subtypes, with lung cancer displaying the highest rates. Additionally, the pathophysiology of cancer-associated ATE involves a multifaceted interplay of cancer-induced hypercoagulopathy, cancer therapy-related thrombosis, and personal risk factor contributors. ATEs are clinically heterogeneous and in the context of cancer have particular mechanistic differences compared with ATE patients without cancer. This requires modifications in approach and tailored management considerations. Specific etiologies contributing to ATE, such as coronary vasospasm and non-bacterial-thrombotic endocarditis, need to be considered. The diagnosis of cancer alone usually does not contraindicate patients to standard guideline-based therapies for the management of ATE, although nuances in treatment may need to be considered in light of the underlying cancer. Atrial fibrillation in cancer patients further complicates the thrombotic landscape. Cancer patients with atrial fibrillation are at a higher risk of ATE, necessitating careful consideration of anticoagulation therapy as clinical benefits and bleeding risks need to be weighed. ATE may also be a presenting sign of underlying malignancy, which requires increased awareness and focused clinical evaluation for cancer in selected cases. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

Development and Validation of an Intracranial Hemorrhage Risk Score in Older Adults with Atrial Fibrillation Treated with Oral Anticoagulant.

Background: High risk of intracranial hemorrhage (ICH) is a leading reason for withholding anticoagulation in patients with atrial fibrillation (AF). We aimed to develop a claims-based ICH risk prediction model in older adults with AF initiating oral anticoagulation (OAC). Methods: We used US Medicare claims data to identify new users of OAC aged ≥65 years with AF in 2010-2017. We used regularized Cox regression to select predictors of ICH. We compared our AF ICH risk score with the HAS-BLED bleed risk and Homer fall risk scores by area under the receiver operating characteristic curve (AUC) and assessed net reclassification improvement (NRI) when predicting 1-year risk of ICH. Results: Our study cohort comprised 840,020 patients (mean [SD] age 77.5 [7.4] years and female 52.2%) split geographically into training (3963 ICH events [0.6%] in 629,804 patients) and validation (1397 ICH events [0.7%] in 210,216 patients) sets. Our AF ICH risk score, including 50 predictors, had superior AUCs of 0.653 and 0.650 in the training and validation sets than the HAS-BLED score of 0.580 and 0.567 (p<0.001) and the Homer score of 0.624 and 0.623 (p<0.001). In the validation set, our AF ICH risk score reclassified 57.8%, 42.5%, and 43.9% of low, intermediate, and high-risk patients, respectively, by HAS-BLED score (NRI: 15.3%, p<0.001). Similarly, it reclassified 0.0, 44.1, and 19.4% of low, intermediate, and high-risk patients, respectively, by the Homer score (NRI: 21.9%, p<0.001). Conclusion: Our novel claims-based ICH risk prediction model outperformed the standard HAS-BLED score and can inform OAC prescribing decisions.

A case of coronary artery compression syndrome resulting from peri-valvular regurgitation and long-standing atrial fibrillation.

A man in his 70s with a history of mitral valve replacement (MVR) and long-standing persistent atrial fibrillation (AF) presented with effort angina. Coronary angiography revealed severe stenosis of the left main coronary artery (LMCA). As it was an emergent case, PCI (percutaneous coronary intervention) was selected for treatment. Intravascular ultrasonography revealed no atherosclerotic lesions in the LMCA. The LMCA was effectively dilated by the drug-eluting stent. No elevation in intracardiac pressure was observed in cardiac catheterization after PCI. Computed tomography scan indicated potential compression of the LMCA by the surrounding structures. In cases of long-standing persistent AF and an enlarged atrium after MVR, the possibility of LMCA stenosis due to anatomical changes should be considered. Learning Objectives: ◾Peri-valvular regurgitation and long-standing persistent atrial fibrillation can potentially cause atrial enlargement.◾Coronary artery stenosis without atherosclerosis can occur due to compression from surrounding structures or shifting of the coronary artery.◾Stent therapy provides a temporary solution and coronary artery bypass grafting or switching should be considered if re-stenosis occurs.