Atrial Fibrillation Group Research Articles

Multi-modal Magnetic Resonance Imaging to Assess Cerebrovascular Function in Atrial Fibrillation Patients

Atrial fibrillation (AF) is associated with an increased risk of cognitive decline, dementia, and stroke. Low cerebral blood flow (CBF) and low cerebrovascular carbon dioxide reactivity (CVRCO2) are associated with poor brain health outcomes. In the current study we employed magnetic resonance imaging (MRI) to quantify resting CBF and CVRCO2 in patients with AF and age-matched normal sinus rhythm (NSR) controls. We hypothesised that both resting CBF and CVRCO2 would be lower in patients with AF. Patients with AF (n=11, 65±14 years, 2 women) and NSR (n=12, 63±9 years, 7 women) underwent arterial spin labelling (ASL) at rest, and blood oxygen level-dependent (BOLD) MRI during a single-step increase in partial pressure of carbon dioxide (measured by end-tidal carbon dioxide (PETCO2)) induced by changing the fraction of inspired CO2 to 5% (21% O2, balance N2). Region of interest time courses were extracted with grey matter, middle cerebral artery, and posterior cerebral artery territory masks. CVRCO2 was defined as the percentage change (%Δ) in BOLD signal vs %Δ in PETCO2. Baseline CBF was not different between NSR and AF in grey matter (62±17 vs. 58±10 ml/min/100g, respectively; p=0.226), middle cerebral artery (59±16 vs. 56±14 ml/min/100g; p=0.361) and posterior cerebral artery (61±17 vs 53±15 ml/min/100g; p=0.138) territories. BOLD-derived CVRC02 was not different between NSR and AF groups in grey matter (0.11±0.04 vs. 0.12±0.03 %ΔBOLD/%ΔmmHg, respectively; p=0.372), middle cerebral artery (0.09±0.04 vs. 0.10±0.03 %ΔBOLD/%ΔmmHg; p=0.405) and posterior cerebral artery (0.13±0.04 vs. 0.14±0.05 %ΔBOLD/%ΔmmHg; p=0.367) territories. Collectively, these pilot data suggest that MRI-derived cerebrovascular CO2 responsiveness is not different in patients with AF and age-matched NSR controls that have similar resting CBF. Further investigations are required to extend these preliminary findings to a larger cohort to fully elucidate the effects of AF on cerebrovascular function. Support provided by the Royal Society of New Zealand Te Apārangi Marsden Fund (19-UOA-170). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

REDUCED AEROBIC FITNESS IS ASSOCIATED WITH IMPAIRED CEREBROVASCULAR FUNCTION IN INDIVIDUALS WITH ATRIAL FIBRILLATION

INTRODUCTION & AIMS Lower aerobic fitness (V̇O2peak) is associated with higher risk of cerebrovascular disease. However, the relationship between V̇O2peak and cerebrovascular function and cerebral blood velocity at rest and during exercise has not been investigated in adults with atrial fibrillation (AF). We aimed to compare resting and exercise cerebral blood velocity responses and cerebrovascular function in individuals with AF to healthy controls. METHODS Eight inactive adults either with AF or healthy age-matched controls (AF: n=4, 64±6 years, 50% female; control: n=4, 66±4 years, 75% female) completed a maximal graded exercise test to measure V̇O2peak. Transcranial Doppler was used to measure bilateral middle cerebral artery velocity (MCAv). Vascular function was assessed by measuring MCAv increases and time to peak following a 30s hypercapnia stimulus (9% CO2, 21% O2, and balanced nitrogen), and MCAv during aerobic exercise (3-minute stages at 40%, 60% and 80% V̇O2peak). Blood pressure, heart rate and end-tidal gases were collected alongside MCAv. RESULTS Compared to controls, individuals with AF (both P<0.01) had higher BMI (AF: 31.8±2.0 kg/m2; control: 27.3±0.6 kg/m2), lower V̇O2peak (AF: 19.9±2.5 mL/kg/min; control: 33.7±5.8 mL/kg/min), and similar blood pressure. Resting right and left MCAv was higher in the AF group (R: 66.6±34.0 cm/s; L: 44.2±10.1 cm/s) compared to the control (R: 36.1±6.7 cm/s; L: 34.9±8.7 cm/s); this was not significant (P=0.121 and 0.258). Right MCAv was higher than left MCAv in individuals with AF but this was not significant (P=0.247). Hypercapnia and exercise induced MCAv and time to peak were similar between groups (P>0.05). CONCLUSION Lower V̇O2peak may be associated with increased resting MCAv in individuals with AF. Furthermore, there may be regional disparities in MCAv in individuals with AF. Future studies with larger sample sizes investigating potential mechanisms and volumetric cerebrovascular changes (e.g., vessel diameter, arterial stiffness) in AF are warranted.

Effects of Atrial Fibrıllation on Cognitive Functions in Patients Between 65-75 Years of Age

Objective: Atrial fibrillation (AF) is the most common arrhythmia in the elderly population and also the most common cause of ischemic stroke. Ischemic stroke is directly related to cognitive decline. The relationship between atrial fibrillation and cognitive decline has long been associated with stroke. This study aimed to reveal whether the mere presence of atrial fibrillation, independent of stroke, has negative effects on cognitive functions. Material and Method: Male and female patients between the ages of 65 and 75 with no chronic diseases other than known hypertension were included in the study. They were divided into two groups according to electrocardiography findings: the group with newly diagnosed atrial fibrillation and the group with normal sinus rhythm (NSR). To evaluate cognitive functions, the Montreal Cognitive Assessment (MoCA) was applied to both groups, and then the groups were compared in terms of scores. Results: No statistically significant difference was observed between the groups in terms of age, patient characteristics, educational status, or laboratory findings. MoCA scores were significantly lower in the AF group than in the NSR group (p=0.001). Multivariable linear regression analysis demonstrated lower age and higher education status were independently associated with high MoCA scores (β: 3.392, 95% CI: 2.375 - 4.410, p

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

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. 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. 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.

Prevalence and Impact of Concomitant Atrial Fibrillation in Patients Undergoing Percutaneous Coronary Intervention for Acute Myocardial Infarction.

Background: Concomitant atrial fibrillation (AF) is associated with an adverse prognosis in patients with acute myocardial infarction (MI). However, it remains unclear whether this is due to a causal effect of AF or whether AF acts as a surrogate marker for comorbidities in this population. Furthermore, there are limited data on whether coronary artery disease distribution impacts the risk of developing AF. Methods: Consecutive patients admitted with acute MI and treated using percutaneous coronary intervention (PCI) at a single centre were retrospectively identified. Associations between AF and major adverse cardiac and cerebrovascular events (MACCEs) over a median of five years of follow-up were assessed using Cox regression, with adjustment for confounding factors performed using both multivariable modelling and a propensity-score-matched analysis. Results: AF was identified in N = 65/1000 (6.5%) of cases; these patients were significantly older (mean: 73 vs. 65 years, p < 0.001), with lower creatinine clearance (p < 0.001), and were more likely to have a history of cerebrovascular disease (p = 0.011) than those without AF. In addition, patients with AF had a greater propensity for left main stem (p = 0.001) or left circumflex artery (p = 0.004) involvement. Long-term MACCE rates were significantly higher in the AF group than in the non-AF group (50.8% vs. 34.2% at five years), yielding an unadjusted hazard ratio (HR) of 1.86 (95% CI: 1.32-2.64, p < 0.001). However, after adjustment for confounding factors, AF was no longer independently associated with MACCEs, either on multivariable (adjusted HR: 1.25, 95% CI: 0.81-1.92, p = 0.319) or propensity-score-matched (HR: 1.04, 95% CI: 0.59-1.82, p = 0.886) analyses. Conclusions: AF is observed in 6.5% of patients admitted with acute MI, and those with AF are more likely to have significant diseases involving left main or circumflex arteries. Although unadjusted MACCE rates were significantly higher in patients with AF, this effect was not found to remain significant after adjustment for comorbidities. As such, this study provided no evidence to suggest that AF is independently associated with MACCEs.

Complex left appendage morphology is associated with Embolic Stroke of Undetermined Source.

Variations in the left atrial appendage (LAA) morphology are associated with different embolic risk in patients with atrial fibrillation (AF). Data are scarce regarding the association between LAA morphology and Embolic stroke of undetermined source (ESUS). Using cardiac computed tomography (CCT) scans, LAA morphology was categorized as either chicken wing (CW), cactus, windsock, or cauliflower. Furthermore, we examined the presence of large secondary lobes arising from the main lobe, considering their existence as indicative of a complex LAA morphology. LAA morphologies were compared between ESUS (n = 134) and AF patients (n = 120); and between ESUS patients with (n = 24) and without (n = 110) subsequent AF diagnosis during long-term follow-up. ESUS patients had a significantly higher prevalence of cauliflower morphology compared to AF group (52% vs 34%, respectively, p = 0.01); however, no significant difference was found between the groups when categorizing LAA morphology to either CW or non-CW. ESUS patients had significantly higher prevalence of large secondary lobes compared with AF patients (50% vs 29%, respectively, p = 0.001). When comparing ESUS patients with and without AF diagnosis during follow-up (20-48 months of follow-up, median 31 months), there were no significant differences in the prevalence of the "classical" morphologies, but large secondary lobes were significantly more prevalent among those without subsequent AF diagnosis. ESUS patients have a high prevalence of complex LAA morphology, which might be associated with an increased risk for thrombus formation even in the absence of AF.

Edge AI Model Deployed for Real-Time Detection of Atrial Fibrillation Risk during Sinus Rhythm.

Objectives: The study aimed to develop a deep learning-based edge AI model deployed on electrocardiograph (ECG) devices for the real-time detection of atrial fibrillation (AF) risk during sinus rhythm (SR) using standard 10 s, 12-lead electrocardiograms (ECGs). Methods: A novel approach was used to convert standard 12-lead ECGs into binary images for model input, and a lightweight convolutional neural network (CNN)-based model was trained using data collected by the Japan Agency for Medical and Research Development (AMED) between 2019 and 2022. Patients over 40 years old with digital, SR ECGs were retrospectively enrolled and divided into AF and non-AF groups. The data labeling was supervised by cardiologists. The dataset was randomly allocated into training, validation, and internal testing datasets. External testing was conducted on data collected from other hospitals. Results: The best-trained model achieved an AUC of 0.82 and 0.80, sensitivity of 79.5% and 72.3%, specificity of 77.8% and 77.7%, precision of 78.2% and 76.4%, and overall accuracy of 78.6% and 75.0% in the internal and external testing datasets, respectively. The deployed model and app package utilized 2.5 MB and 40 MB of the available ROM and RAM capacity on the edge ECG device, correspondingly. The processing time for AF risk detection was approximately 2 s. Conclusions: The model maintains comparable performance and improves its suitability for deployment on resource-constrained ECG devices, thereby expanding its potential impact to a wide range of healthcare settings. Its successful deployment enables real-time AF risk detection during SR, allowing for timely intervention to prevent AF-related serious consequences like stroke and premature death.

The Effects of Radiofrequency Catheter Ablation for Atrial Fibrillation on Right Ventricular Function.

The effects of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) on right ventricular (RV) function are not well known. Patients who underwent RFCA for AF and underwent pre- and post-procedural echocardiography were enrolled consecutively. Fractional area change (FAC), RV free-wall longitudinal strain (RVFWSL), and RV 4-chamber strain including the ventricular septum (RV4CSL) were measured. Changes in FAC, RVFWSL, and RV4CSL before and after RFCA were compared among paroxysmal AF (PAF), persistent AF (PeAF), and long-standing persistent AF (LSPeAF) groups. A total of 164 participants (74 PAF, 47 PeAF, and 43 LSPeAF; age, 60.8 ± 9.8 years; men, 74.4%) was enrolled. The patients with PeAF and LSPeAF had worse RV4CSL (p<0.001) and RVFWSL (p<0.001) than those with PAF and reference values. Improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared with the PAF and LSPeAF groups (ΔRV4CSL, 8.4% [5.1, 11.6] in PeAF vs. 1.0% [-1.0, 4.1] in PAF, 1.9% [-0.2, 4.4] in LSPeAF, p<0.001; ΔRVFWSL, 9.0% [6.9, 11.5] in PeAF vs. 0.9% [-1.4, 4.9] in PAF, 1.0% [-1.0, 3.6] in LSPeAF, p<0.001). In patients without recurrence, improvements in RVFWSL and RV4CSL after RFCA were significant in the PeAF group compared to the LSPeAF group. RV systolic function is more impaired in patients with PeAF and LSPeAF than in those with PAF. RV systolic function is more improved after RFCA in patients with PeAF than in those with PAF or LSPeAF.

A three-dimensional left atrial motion estimation from retrospective gated computed tomography: application in heart failure patients with atrial fibrillation.

A reduced left atrial (LA) strain correlates with the presence of atrial fibrillation (AF). Conventional atrial strain analysis uses two-dimensional (2D) imaging, which is, however, limited by atrial foreshortening and an underestimation of through-plane motion. Retrospective gated computed tomography (RGCT) produces high-fidelity three-dimensional (3D) images of the cardiac anatomy throughout the cardiac cycle that can be used for estimating 3D mechanics. Its feasibility for LA strain measurement, however, is understudied. The aim of this study is to develop and apply a novel workflow to estimate 3D LA motion and calculate the strain from RGCT imaging. The utility of global and regional strains to separate heart failure in patients with reduced ejection fraction (HFrEF) with and without AF is investigated. A cohort of 30 HFrEF patients with (n = 9) and without (n = 21) AF underwent RGCT prior to cardiac resynchronisation therapy. The temporal sparse free form deformation image registration method was optimised for LA feature tracking in RGCT images and used to estimate 3D LA endocardial motion. The area and fibre reservoir strains were calculated over the LA body. Universal atrial coordinates and a human atrial fibre atlas enabled the regional strain calculation and the fibre strain calculation along the local myofibre orientation, respectively. It was found that global reservoir strains were significantly reduced in the HFrEF + AF group patients compared with the HFrEF-only group patients (area strain: 11.2 ± 4.8% vs. 25.3 ± 12.6%, P = 0.001; fibre strain: 4.5 ± 2.0% vs. 15.2 ± 8.8%, P = 0.001), with HFrEF + AF patients having a greater regional reservoir strain dyssynchrony. All regional reservoir strains were reduced in the HFrEF + AF patient group, in whom the inferior wall strains exhibited the most significant differences. The global reservoir fibre strain and LA volume + posterior wall reservoir fibre strain exceeded LA volume alone and 2D global longitudinal strain (GLS) for AF classification (area-under-the-curve: global reservoir fibre strain: 0.94 ± 0.02, LA volume + posterior wall reservoir fibre strain: 0.95 ± 0.02, LA volume: 0.89 ± 0.03, 2D GLS: 0.90 ± 0.03). RGCT enables 3D LA motion estimation and strain calculation that outperforms 2D strain metrics and LA enlargement for AF classification. Differences in regional LA strain could reflect regional myocardial properties such as atrial fibrosis burden.

Difference in radiofrequency ablation profile between during sinus rhythm and atrial fibrillation: Considerations in this era of high‐power short‐duration strategy

AbstractBackgroundThe concept of ablation index (AI) was introduced to evaluate radiofrequency (RF) ablation lesions. It is calculated from power, contact force (CF), and RF duration. However, other factors may also affect the quality of ablation lesions. To examine the difference in RF lesions made during sinus rhythm (SR) and atrial fibrillation (AF).MethodsSixty patients underwent index pulmonary vein isolation during SR (n = 30, SR group) or AF (n = 30, AF group). All ablations were performed with a power of 50 W, a targeted CF of 5–15 g, and AI of 400–450 using Thermocool Smarttouch SF. The CF, AI, RF duration, temperature rise (Δtemp), impedance drop (Δimp), and the CF stability of each ablation point quantified as the standard deviation of the CF (CF‐SD) were compared between the two groups.ResultsA total of 3579 ablation points were analyzed, which included 1618 and 1961 points in the SR and the AF groups, respectively. Power, average CF, RF duration per point, and the resultant AI (389 ± 59 vs. 388 ± 57) were similar for the two rhythms. However, differences were seen in the CF‐SD (3.5 ± 2.2 vs. 3.8 ± 2.1 g, p &lt; .01), Δtemp (3.8 ± 1.3 vs. 4.0 ± 1.3°C, p &lt; .005), and Δimp (10.3 ± 5.8 vs. 9.4 ± 5.4 Ω, p &lt; .005).ConclusionsDespite similar AI, various RF parameters differed according to the underlying atrial rhythm. Ablation delivered during SR demonstrated less CF variability and temperature increase and greater impedance drop than during AF.

Utilizing RNA sequencing to identify gene expression markers of stroke-causing thrombi origin: A pilot study

IntroductionStroke embolic source have an unknown origin in 30-40% of cases. Mechanical thrombectomy for acute large vessel occlusion stroke has provided us with a method to directly retrieve the thrombi from patients for analysis. By collecting stroke-causing thrombi from known sources, we can then use high-throughput RNA sequencing (RNAseq) technology to directly measure the gene expression signatures of these clots. This may allow us to identify genetic markers to predict the cause of cryptogenic embolism. MethodsThis is a prospective study in which RNAseq was used to analyze cerebral thrombi retrieved by mechanical thrombectomy devices in acute ischemic stroke patients. Samples were separated into two groups based on known stroke thrombus etiology, including Carotid group (patients with ipsilateral >70% carotid stenosis) and Atrial fibrillation (AF) group (patients with atrial fibrillation). Gene expression was compared by RNAseq analysis between the groups. ResultsFrom October 2016 to September 2017, 8 thrombi (4 in Carotid group, 4 in Afib group) were included in this study. There were 131 genes that were significantly up- or down-regulated between the two groups defined as a false discovery rate ≤ 0.05 and a fold change ≥ 2. Twenty-six genes were selected as candidate gene biomarkers based on the criteria in the methods section. Candidate genes HSPA1B, which encodes a heatshock protein, and GPRC5B, which encodes a G-protein, showed the greatest fold differences in expression between the two groups. ConclusionThis study has shown that RNA sequencing of acute ischemic stroke thrombi is feasible and indentified potential novel biomarkers for identifying stroke-causing thrombi origin, especially in cryptogenic stroke.

Left atrial shape as a marker of atrial myopathy in embolic stroke of undetermined source.

Embolic stroke of undetermined source (ESUS) results in significant morbidity. A left atrial (LA) myopathy is implicated in a proportion of these patients. We hypothesized that LA shape varies by cause of stroke [CE (cardioembolic) vs. ESUS]. A total of 236 ischaemic stroke and atrial fibrillation (AF) patients and controls were recruited prospectively. AF was classified as paroxysmal AF (PAF) or persistent AF (PersAF). Stroke patients comprised CE stroke secondary to AF and ESUS. There were 81 AF (47 PAF, 34 PersAF), 50 ESUS, 57 CE patients [subdivided into CE with PAF (CEpaf) and CE with PersAF (CEpers)], and 48 controls. Echocardiographic parameters including LA volume, function, and shape/sphericity (3D LA sphericity and 2D-derived LA circularity, ellipticity, sphericity, and eccentricity indices) were evaluated. Increased LA volume and sphericity with LA dysfunction were present in CE, AF, and ESUS groups compared with controls. K-means cluster analysis demonstrated a spectrum of LA myopathy with controls at the lowest and CEpers and PersAF at the upper extremes, with ESUS, PAF, and CEpaf being similar and falling between these extremes. After adjusting for age, sex, and left ventricular (LV) and LA parameters, LA sphericity markers differentiated ESUS from controls (P < 0.01). Alterations in LA shape are present in ESUS, AF, and CE patients, particularly increased spherical remodelling. The novel markers of LA sphericity proposed may identify LA myopathy in ESUS patients and potentially guide management for secondary prevention.

Evaluation of an Optimized Workflow for the Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation.

BACKGROUND A significant number of atrial fibrillation (AF) recurrences occur after initial ablation, often due to pulmonary vein reconnections or triggers from non-pulmonary veins. MATERIAL AND METHODS Patients with paroxysmal AF who underwent radiofrequency catheter ablation for the first time were enrolled. Base on propensity score matching (1: 1 matching), 118 patients were selected for an optimized workflow for the radiofrequency catheter ablation of paroxysmal AF (OWCA) group and a conventional group. Comparative analysis of the acute and 12-month clinical outcomes was conducted. Moreover, an artificial intelligence analytics platform was used to evaluate the quality of pulmonary vein isolation (PVI) circles. RESULTS PVI was successfully achieved in all patients. Incidence of first-pass isolation of bilateral PVI circles was higher (P=0.009) and acute pulmonary vein reconnections was lower (P=0.027) in the OWCA group than conventional group. The OWCA group displayed a significant reduction in the number of fractured points (P<0.001), stacked points (P=0.003), and a greater proportion of cases in which the radiofrequency index achieved the target value (P=0.003). Additionally, the contact force consistently met the force over time criteria (P<0.001) for bilateral PVI circles in the OWCA group, accompanied by a shorter operation time (P=0.017). During the 12-month follow-up period, the OWCA group exhibited a higher atrial arrhythmia-free survival rate following the initial ablation procedure than did the conventional group. CONCLUSIONS The optimized workflow for radiofrequency catheter ablation of paroxysmal AF could play a crucial role in creating higher quality PVI circles. This improvement is reflected in a significantly elevated 12-month atrial arrhythmia-free survival rate.

Quantitative assessment of left ventricular myocardial work in patients with different types of atrial fibrillation by non-invasive pressure-strain loop technique.

This study aimed to analyze myocardial work in patients with atrial fibrillation (AF) using a noninvasive pressure strain loop (PSL) technique to provide a basis for the quantitative assessment of left ventricular (LV) systolic function. LV myocardial work of 107 AF patients (56 with paroxysmal atrial fibrillation and 51 with persistent atrial fibrillation) and 55 healthy individuals were assessed by the noninvasive PSL and then compared. Global longitudinal strain (GLS) in absolute values, global work index (GWI), global constructive work (GCW), and global work efficiency (GWE) were significantly lower in the AF group than control group, whereas peak strain dispersion (PSD) and global wasted work (GWW) were significantly higher (P<.05). Further subdivision according to the AF type revealed that, compared with the controls, GLS in absolute values and GWE decreased significantly; PSD and GWW increased significantly in the paroxysmal AF group (P<.05). Nevertheless, GWI and GCW were not significantly different between paroxysmal AF and control groups (P>.05). Compared to paroxysmal AF, persistent AF induced a further decrease in absolute GLS and GWE and a further increase in GWW (P<.05), but PSD did not increase further (P>.05). Multiple linear regression analysis showed that GWI and GCW were independently associated with systolic blood pressure. GWW was associated with types of AF and left atrial volume index (LAVI). GWE was correlated with age, types of AF, disease duration, and LAVI. Receiver operating characteristic curve analysis showed that the area under the curve predicting myocardial injury was higher for GWE and GWW than for GLS (area under the curve: .880, .846, and .821, respectively). Non-invasive PSL can quantitatively assess LV systolic function in patients with different kinds of AF and detect early subclinical myocardial injury in patients with paroxysmal AF. GWE and GWW outperform GLS and LV ejection fraction when assessing myocardial injury. Systolic blood pressure, type of AF, LVAI, disease duration, and age may be associated with myocardial injury in patients with AF.

Predictive nomogram models for atrial fibrillation in COPD patients: A comprehensive analysis of risk factors and prognosis.

The aim of the present study was to identify the independent risk factors and prognostic indicators for atrial fibrillation (AF) in patients with chronic obstructive pulmonary disease (COPD) and to develop predictive nomogram models. This retrospective study included a total of 286 patients with COPD who were admitted to the Second Affiliated Hospital of Guilin Medical College between January 2020 and May 2022. The average age of the patients was 77.11±8.67 years. Based on the presence or absence of AF, the patients were divided into two groups: The AF group (n=87) and the non-AF group (n=199). Logistic regression analysis was conducted to identify variables with significant differences between the two groups. Nomogram models were constructed to predict the occurrence of AF in COPD patients and to assess prognosis. Survival analysis was performed using the Kaplan-Meier method. The follow-up period for the present study extended until April 31, 2023. Survival time was defined as the duration from the date of the interview to the date the participant succumbed or the end of the follow-up period. In the present study, age, uric acid (UA) and left atrial diameter (LAD) were found to be independent risk factors for the development of AF in patients diagnosed with COPD. The stepwise logistic regression analysis revealed that age had an odds ratio (OR) of 1.072 [95% confidence interval (CI): 1.019-1.128; P=0.007], UA had an OR of 1.004 (95% CI: 1.001-1.008; P=0.010) and LAD had an OR of 1.195 (95% CI: 1.098-1.301; P<0.001). Univariate and multivariate Cox regression analysis revealed that LAD and UA were independent prognostic factors for long-term mortality in COPD patients with AF. LAD had a hazard ratio (HR) of 1.104 (95% CI: 1.046-1.165; P<0.001) and UA had an HR of 1.004 (95% CI: 1.000-1.008; P=0.042). Based on these findings, predictive nomogram models were developed for AF in COPD patients, which demonstrated good discrimination ability with an area under the curve of 0.886. The prognostic nomogram for COPD patients with AF also showed good predictive accuracy with a concordance index of 0.886 (95% CI: 0.842-0.930). These models can provide valuable information for risk assessment and prognosis evaluation in clinical practice. Age, UA and LAD are independent risk factors for AF in COPD patients. The developed nomogram models provide a reliable tool for predicting AF in COPD patients and for prognosis assessment.

Is atrial fibrillation in HFpEF a distinct phenotype? Insights from multiparametric MRI and circulating biomarkers

BackgroundHeart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) frequently co-exist. There is a limited understanding on whether this coexistence is associated with distinct alterations in myocardial remodelling and mechanics. We aimed to determine if patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) represent a distinct phenotype.MethodsIn this secondary analysis of adults with HFpEF (NCT03050593), participants were comprehensively phenotyped with stress cardiac MRI, echocardiography and plasma fibroinflammatory biomarkers, and were followed for the composite endpoint (HF hospitalisation or death) at a median of 8.5 years. Those with AF were compared to sinus rhythm (SR) and unsupervised cluster analysis was performed to explore possible phenotypes.Results136 subjects were included (SR = 75, AF = 61). The AF group was older (76 ± 8 vs. 70 ± 10 years) with less diabetes (36% vs. 61%) compared to the SR group and had higher left atrial (LA) volumes (61 ± 30 vs. 39 ± 15 mL/m2, p < 0.001), lower LA ejection fraction (EF) (31 ± 15 vs. 51 ± 12%, p < 0.001), worse left ventricular (LV) systolic function (LVEF 63 ± 8 vs. 68 ± 8%, p = 0.002; global longitudinal strain 13.6 ± 2.9 vs. 14.7 ± 2.4%, p = 0.003) but higher LV peak early diastolic strain rates (0.73 ± 0.28 vs. 0.53 ± 0.17 1/s, p < 0.001). The AF group had higher levels of syndecan-1, matrix metalloproteinase-2, proBNP, angiopoietin-2 and pentraxin-3, but lower level of interleukin-8. No difference in clinical outcomes was observed between the groups. Three distinct clusters were identified with the poorest outcomes (Log-rank p = 0.029) in cluster 2 (hypertensive and fibroinflammatory) which had equal representation of SR and AF.ConclusionsPresence of AF in HFpEF is associated with cardiac structural and functional changes together with altered expression of several fibro-inflammatory biomarkers. Distinct phenotypes exist in HFpEF which may have differing clinical outcomes.

Prevalence of Obstructive Sleep Apnea Among Atrial Fibrillation Patients: A Cross-Sectional Study from Jordan.

Obstructive Sleep Apnea (OSA) is a common respiratory disorder that causes intermittent upper airway collapse during sleep and can lead to various acute cardiovascular complications. Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with an increased risk of cardiovascular hospitalization and all-cause mortality. Our study aimed to investigate the prevalence of individuals with AF and those considered at high risk for OSA. A cross-sectional study was conducted with a population comprising patients who had visited KAUH cardiology clinics between 2017-2019; subjects were categorized into AF patients and general cardiology patients. Patients were surveyed for OSA using the Berlin Questionnaire to assess the degree of OSA symptoms and to classify patients into high- or low-risk groups based on their responses. Of the 656 patients, 545 met our inclusion criteria, of whom 192 were diagnosed with AF. Comparable demographic characteristics were observed between the AF and non-AF groups, barring higher rates of obesity (p=0.001) and smoking (p=0.042) in the AF group. The prevalence of high-risk OSA was significantly higher in AF patients (68.2%) compared to non-AF patients (29.4%), with an adjusted odds ratio of 2.473 times (95% CI: 1.434 -4.266, p=0.001) greater for AF. The age, gender, and BMI categories did not differ significantly between the two groups. Binary logistic regression revealed significant associations between OSA and risk factors such as asthma (OR=4.408, 95% CI: 2.634-7.376, p=0.001). These results serve to display a statistically significant increase in high-risk OSA in existing AF patients, irrespective of the presence of conventional OSA risk factors; this could imply a more immediate and direct relationship between both diseases and calls to include routine screening for OSA in patients diagnosed, newly or otherwise, with AF.

Characteristics and Outcomes of Atrial Fibrillation in Chronic Heart Failure Patients: A Comprehensive Analysis of the Colombian Heart Failure Registry.

Heart failure (HF) and atrial fibrillation (AF) represent conditions that commonly coexist. The impact of AF in HF has yet to be well studied in Latin America. This study aimed to characterize the sociodemographic and clinical features, along with patients' outcomes with AF and HF from the Colombian Heart Failure Registry (RECOLFACA). Patients with ambulatory HF and AF were included in RECOLFACA, mainly with persistent or permanent AF. A 6-month follow-up was performed. Primary outcome was all-cause mortality. To assess the impact of AF on mortality, we used a logistic regression model. A P value of < 0.05 was considered significant. All statistical tests were two-tailed. Of 2,528 patients with HF in the registry, 2,514 records included information regarding AF diagnosis. Five hundred sixty (22.3%) were in AF (mean age 73 ± 11, 56% men), while 1,954 had no AF (mean age 66 ± 14 years, 58% men). Patients with AF were significantly older and had a different profile of comorbidities and implanted devices compared to non-AF patients. Moreover, AF diagnosis was associated with lower quality of life score (EuroQol-5D), mainly in mobility, personal care, and daily activity. AF was prevalent in patients with preserved ejection fraction (EF), while no significant differences in N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels were observed. Although higher mortality was observed in the AF group compared to individuals without AF (8.9% vs. 6.1%, respectively; P = 0.016), this association lost statistical significance after adjusting by age in a multivariate regression model (odds ratio (OR): 1.35; 95% confidence interval (CI): 0.95 - 1.92). AF is more prevalent in HF patients with higher EF, lower quality of life and different clinical profiles. Similar HF severity and non-independent association with mortality were observed in our cohort. These results emphasize the need for an improved understanding of the AF and HF coexistence phenomenon.

Impact of Comorbid Sleep-Disordered Breathing and Atrial Fibrillation on the Long-Term Outcome After Ischemic Stroke.

Sleep-disordered breathing (SDB) and atrial fibrillation (AF) are highly prevalent in patients with stroke and are recognized as independent risk factors for stroke. Little is known about the impact of comorbid SDB and AF on long-term outcomes after stroke. In this prospective cohort study, 353 patients with acute ischemic stroke or transient ischemic attacks were analyzed. Patients were screened for SDB by respiratory polygraphy during acute hospitalization. Screening for AF was performed using a 7-day ECG up to 3× in the first 6 months. Follow-up visits were scheduled at 1, 3, 12, 24, and 36 months poststroke. Cox regression models adjusted for various factors (age, sex, body mass index, hypertension, diabetes, dyslipidemia, and heart failure) were used to assess the impact of comorbid SDB and AF on subsequent death or cerebro-cardiovascular events. Among 353 patients (299 ischemic stroke and 54 transient ischemic attacks), median age, 67 (interquartile range, 57-74) years with 63% males. Moderate-to-severe SDB (apnea-hypopnea index score, ≥15/h) was present in 118 (33.4%) patients. Among the 56 (15.9%) patients with AF, 28 had comorbid moderate-to-severe SDB and AF. Over 36 months, there were 12 deaths and 67 recurrent cerebro-cardiovascular events. Patients with comorbid moderate-to-severe SDB and AF had a higher risk of subsequent death or cerebro-cardiovascular events compared with those with only moderate-to-severe SDB without AF (hazard ratio, 2.49 [95% CI, 1.18-5.24]) and to those without moderate-to-severe SDB or AF (hazard ratio, 2.25 [95% CI, 1.12-4.50]). However, no significant difference was found between the comorbid moderate-to-severe SDB and AF group and the group with only AF without moderate-to-severe SDB (hazard ratio, 1.64 [95% CI, 0.62-4.36]). Comorbid moderate-to-severe SDB and AF significantly increase the risk of long-term mortality or recurrent cerebro-cardiovascular events after acute ischemic stroke. Considering both conditions as cumulative and modifiable cerebro-cardiovascular risk factors is of interest for the management of acute stroke. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02559739.

Oral anticoagulants increased 30-day survival in sepsis patients complicated with atrial fibrillation: a retrospective analysis from MIMIC-IV database.

The severity of sepsis is associated with systemic clotting activation. Atrial fibrillation (AF) is the most commonly observed arrhythmia in patients with sepsis and can lead to a poor prognosis. The aim of this study is to elucidate the association between oral anticoagulants and survival from septic patients complicated with AF. The data of 8,828 septic patients, including 2,955 AF and 5,873 without AF, were all originated from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Patients with sepsis and AF are divided into OAC- group (n = 1,774) and OAC+ group (n = 1,181) based on OAC therapy. Septic patients with no AF were considered as the control group (n = 5,873, sepsis and no AF group). The main outcome endpoint was the survival rate of 30 day. The secondary outcome endpoint was the length of stay (LOS) from intensive care unit and hospital. Propensity score matching (PSM) was used to adjust the influence of superfluous factors, and a restricted mean survival time (RMST) analysis was used for calculating the benefit of survival time and survival rate. Analysis including univariate and multivariate logistic regression analysis was conducted to find prognosis-related predictors. After PSM, the OAC+group had a higher 30-day survival rate compared to the OAC- group (81.59% vs. 58.10%; P < 0.001) in the ICU. Despite the higher survival, the hospital LOS (14.65 days vs. 16.66 days; P = 0.15) and ICU LOS (6.93 days vs. 5.92 days; P = 0.02) were prolonged at OAC+ group than OAC- group. No difference was found in survival rate of 30 day between the sepsis patients using warfarin and patients using NOAC (85.60% vs. 79.84%, P = 0.12). The sepsis patients using warfarin had a prolonged LOS in ICU and hospital compared with the sepsis patients using NOAC. In the vasopressor subgroup, patients who received NOAC therapy were associated with a reduced 30-day survival rate (73.57% vs. 84.03%; P = 0.04) and reduced LOS in ICU and hospital than those on warfarin therapy. This study demonstrated that oral anticoagulants may increase the 30-day survival rate of patients with sepsis and AF.