Atrial Fibrillation Rhythm Research Articles

Abstract 18187: Scoring System to Predict Reduced Left Atrial Appendage Emptying Velocity

Introduction: Left atrial appendage emptying velocity (LAAev) as assessed on transesophageal echocardiography (TEE) is a surrogate for propensity for LAA thrombus and cardioembolic stroke. Identifying patients with decreased LAAev is important for risk stratification. CHA 2 DS 2 -VASc score is used to stratify stroke risk in atrial fibrillation (AF) but does not incorporate rhythm, type of atrial fibrillation or transthoracic echocardiography (TTE). Objective: To create a composite scoring system using clinical and TTE variables to predict reduced LAAev. Methods: We searched TEE reports of unique patients from 2016-2022 at the University of Kansas Medical Center. Additional information was extracted from review of TEE imaging, TTE reports and detailed medical chart review. Significant univariate predictors of reduced LAAev (<30 cm/s) were added to a stepwise selection multivariable logistic regression model with significance level for entry and stay 0.15. Based on their respective odds ratios, selected variables were assigned different point values to create a risk score. Results: We included 995 patients (women 38.1% men, age 71.3±12.7 yrs, white 89.3%, LAAev 41.6±21.0 cm/s). The derived score includes different points assigned for long-standing persistent/permanent AF, persistent AF, paroxysmal AF, current rhythm AF, coronary artery disease, congestive heart failure, female sex, age ≥70 yrs and negative points for >moderate mitral regurgitation; categorized into high, intermediate and low risk (see Figure). The rate of reduced LAAev <30 cm/s was respectively 55.7%, 35.2% and 9.0%. Conclusions: Our scoring system was able to stratify risk of reduced LAAev and needs to be validated in independent datasets.

Functional mapping to reveal slow conduction and substrate progression in atrial fibrillation.

The aim of our study was to analyse the response to short-coupled atrial extrastimuli to identify areas of hidden slow conduction (HSC) and their relationship with the atrial fibrillation (AF) phenotype. Twenty consecutive patients with paroxysmal AF and persistent AF (10:10) underwent the first pulmonary vein isolation procedure. Triple short-coupled extrastimuli were delivered in sinus rhythm (SR), and the evoked response was analysed: sites exhibiting double or highly fragmented electrograms (EGM) were defined as positive for HSC (HSC+). The delta of the duration of the bipolar EGM was analysed, and bipolar EGM duration maps were built. High-density maps were acquired using a multipolar catheter during AF, SR, and paced rhythm. Spatial co-localization of HSC+ and complex fractionated atrial EGMs (CFAE) during AF was evaluated. Persistent AF showed a higher number and percentage of HSC+ than paroxysmal AF (13.9% vs. 3.3%, P < 0.001). The delta of EGM duration was 53 ± 22 ms for HSC+ compared with 13 ± 11 (10) ms in sites with negative HSC (HSC-) (P < 0.001). The number and density of HSC+ were lower than CFAE during AF (19 vs. 56 per map, P < 0.001). The reproducibility and distribution of HSC+ in repeated maps were superior to CFAE (P = 0.19 vs. P < 0.001). Sites with negative and positive responses showed a similar bipolar voltage in the preceding sinus beat (1.65 ± 1.34 and 1.48 ± 1.47 mV, P = 0.12). Functional mapping identifies more discrete and reproducible abnormal substrates than mapping during AF. The HSC+ sites in response to triple extrastimuli are more frequent in persistent AF than in paroxysmal AF.

Natriuretic Peptide Receptor B Protects Against Atrial Fibrillation by Controlling Atrial cAMP Via Phosphodiesterase 2.

β-AR (β-adrenergic receptor) stimulation regulates atrial electrophysiology and Ca2+ homeostasis via cAMP-dependent mechanisms; however, enhanced β-AR signaling can promote atrial fibrillation (AF). CNP (C-type natriuretic peptide) can also regulate atrial electrophysiology through the activation of NPR-B (natriuretic peptide receptor B) and cGMP-dependent signaling. Nevertheless, the role of NPR-B in regulating atrial electrophysiology, Ca2+ homeostasis, and atrial arrhythmogenesis is incompletely understood. Studies were performed using atrial samples from human patients with AF or sinus rhythm and in wild-type and NPR-B-deficient (NPR-B+/-) mice. Studies were conducted in anesthetized mice by intracardiac electrophysiology, in isolated mouse atrial preparations using high-resolution optical mapping, in isolated mouse and human atrial myocytes using patch-clamping and Ca2+ imaging, and in mouse and human atrial tissues using molecular biology. Atrial NPR-B protein levels were reduced in patients with AF, and NPR-B+/- mice were more susceptible to AF. Atrial cGMP levels and PDE2 (phosphodiesterase 2) activity were reduced in NPR-B+/- mice leading to larger increases in atrial cAMP in the presence of the β-AR agonist isoproterenol. NPR-B+/- mice displayed larger increases in action potential duration and L-type Ca2+ current in the presence of isoproterenol. This resulted in the occurrence of spontaneous sarcoplasmic reticulum Ca2+ release events and delayed afterdepolarizations in NPR-B+/- atrial myocytes. Phosphorylation of the RyR2 (ryanodine receptor) and phospholamban was increased in NPR-B+/- atria in the presence of isoproterenol compared with the wildtypes. C-type natriuretic peptide inhibited isoproterenol-stimulated L-type Ca2+ current through PDE2 in mouse and human atrial myocytes. NPR-B protects against AF by preventing enhanced atrial responses to β-adrenergic receptor agonists.

Blood pressure in atrial fibrillation and in sinus rhythm during ambulatory blood pressure monitoring: data from the TEMPLAR project

The coexistence of hypertension and atrial fibrillation (AF) is common and accounts for a worse prognosis. Uncertainties exist regarding blood pressure (BP) measurements in AF patients by automated oscillometric devices. The Microlife WatchBP 03 AFIB ambulatory BP monitoring (ABPM) device including an AF algorithm with each measurement was used in 430 subjects aged >65 years referred for ABPM and with assumed paroxysmal AF to perform intra-individual comparisons of BP during both AF-indicated and sinus rhythm. Only subjects with >30% of measurements indicating AF and episodes >30 min for assumed AF and for sinus rhythm were included. Mean age was 78 ± 7 years, 43% were male, 77% hypertensive, and 72% were treated. Compared to sinus rhythm, 24-h mean arterial pressure was similar (87.2 ± 9.5 vs 87.5 ± 10.6 mm Hg, p = 0.47), whereas 24-h systolic BP tended to be lower (123.6 ± 13.9 vs 124.7 ± 16.1 mm Hg, p = 0.05) and night-time diastolic BP higher (64.6 ± 10.9 vs 63.3 ± 10.4 mm Hg, p = 0.01) in assumed AF. Diastolic (not systolic) BP variability was higher in AF (p < 0.001). Results were similar with heart rates <90 and ≥90 bpm. In conclusion, this is the first study to use intra-individual comparisons of averaged BP during an ABPM in assumed paroxysmal AF and sinus rhythm. Our results imply that ABPM is feasible and informative also in patients with AF. We also suggest that an AF detection algorithm offers a new approach to evaluate the reliability of averaged BP values in AF compared to SR during an ABPM.

Prognostic Impact of Atrial Fibrillation in Patients with Heavily Calcified Coronary Artery Disease Receiving Rotational Atherectomy.

Background and Objectives: Although both rotational atherectomy (RA) and atrial fibrillation (AF) have a high thrombotic risk, there have been no previous studies on the prognostic impact of AF in patients who undergo percutaneous coronary intervention (PCI) using RA. Thus, the aim of the present study was to determine the prognostic impact of AF in patients undergoing PCI using RA. Materials and Methods: A total of 540 patients who received PCI using RA were enrolled between January 2010 and October 2019. Patients were divided into AF and sinus rhythm groups according to the presence of AF. The primary endpoint was net adverse clinical events (NACEs) defined as a composite outcome of all-cause death, myocardial infarction, target vessel revascularization, cerebrovascular accident, or total bleeding. Results: Although in-hospital adverse events showed no difference between those with AF and those without AF (in-hospital events, 54 (11.0%) vs. 6 (12.2%), p = 0.791), AF was strongly associated with an increased risk of NACE at 3 years (NACE: hazard ratio, 1.880; 95% confidence interval, 1.096-3.227; p = 0.022). Conclusions: AF in patients who underwent PCI using RA was strongly associated with poor clinical outcomes. Thus, more attention should be paid to thrombotic and bleeding risks.

Comparison of pulmonary vein isolation using cryoballoon, high-power short-duration, and conventional radiofrequency ablation for atrial fibrillation: a propensity score-weighted study.

The comparative efficacy, saftey, and heart rate variability (HRV) parameters after pulmonary vein isolation using cryoballoon (Cryo-PVI), high-power short-duration (HPSD-PVI), and conventional radiofrequency ablation (conventional-PVI) for atrial fibrillation (AF) is unclear. In this propensity score-weighted, retrospective analysis of a single-center cohort, we analyzed 3,395 patients (26.2% female, 74.5% paroxysmal AF) who underwent AF catheter ablation without an empirical left atrial ablation. Procedural factors, recurrence rates, complication rates, and the post-procedural HRV parameters were compared across the Cryo-PVI (n = 625), HPSD-PVI (n = 748), and conventional-PVI (n = 2,022) groups. Despite the shortest procedural time in the Cryo-PVI group (74 min for Cryo-PVI vs. 104 min for HPSD-PVI vs. 153 min for conventional-PVI, p < 0.001), the major complication (p = 0.906) and clinical recurrence rates were similar across the three ablation groups (weighted log-rank, p = 0.824). However, the Cryo-PVI group was associated with a significantly lower risk of recurrent AF in patients with paroxysmal AF [weighted hazard ratio (WHR) 0.57, 95% confidence interval (CI) 0.37-0.86], whereas it was associated with a higher risk of recurrent AF in patients with persistent AF (WHR 1.41, 95% CI 1.06-1.89, p for interaction of <0.001) compared with the conventional-PVI group. In the subgroup analysis for the HRV, the Cryo-PVI group had the highest low-frequency-to-high-frequency ratio at 1-year post-procedure, whereas the HPSD-PVI group had the lowest low-frequency-to-high-frequency ratio at 1-year post-procedure (p < 0.001). The Cryo-PVI group had better rhythm outcomes in patients with paroxysmal AF but worse rhythm outcomes in patients with persistent AF and a higher long-term post-procedural sympathetic nervous activity and sympatho-vagal balance compared with the conventional-PVI group.

Role of Malnutrition in Atrial Fibrillation: A Prospective Study including Individuals ≥ 75 Years of Age.

Atrial fibrillation (AF) is the most common rhythm disorder in the elderly. The AF can cause life-threatening thromboembolic complications. Therefore, there is a need to determine the risk factors of AF. In this study, we aimed to examine the association of markers of malnutrition with AF in individuals aged 75 years and older and to find the factors that may affect mortality. In this prospective study, 358 consecutive individuals aged 75 years and older presenting to the cardiology outpatient clinic were included. All participants were divided into AF and sinus rhythm (SR) groups. In addition, a questionnaire and scoring system were used to assess malnutrition status. Information was obtained from all patients through outpatient clinic visits or telephone interviews for one year. Death from any cause was considered as the endpoint. AF was observed in 71 (19.8%) patients. Death was higher in patients with AF (p < 0.001), high CONUT score (p = 0.018), and GLIM malnutrition (p = 0.018). GLIM malnutrition caused a 2.8-fold increase in the development of AF. Screening for malnutrition in the elderly is essential. According to GLIM criteria, malnutrition may play a role in the development of AF and increase one-year mortality in the elderly.

PPP1R12C Promotes Atrial Hypocontractility in Atrial Fibrillation.

Atrial fibrillation (AF)-the most common sustained cardiac arrhythmia-increases thromboembolic stroke risk 5-fold. Although atrial hypocontractility contributes to stroke risk in AF, the molecular mechanisms reducing myofilament contractile function remain unknown. We tested the hypothesis that increased expression of PPP1R12C (protein phosphatase 1 regulatory subunit 12C)-the PP1 (protein phosphatase 1) regulatory subunit targeting MLC2a (atrial myosin light chain 2)-causes hypophosphorylation of MLC2a and results in atrial hypocontractility. Right atrial appendage tissues were isolated from human patients with AF versus sinus rhythm controls. Western blots, coimmunoprecipitation, and phosphorylation studies were performed to examine how the PP1c (PP1 catalytic subunit)-PPP1R12C interaction causes MLC2a dephosphorylation. In vitro studies of pharmacological MRCK (myotonic dystrophy kinase-related Cdc42-binding kinase) inhibitor (BDP5290) in atrial HL-1 cells were performed to evaluate PP1 holoenzyme activity on MLC2a. Cardiac-specific lentiviral PPP1R12C overexpression was performed in mice to evaluate atrial remodeling with atrial cell shortening assays, echocardiography, and AF inducibility with electrophysiology studies. In human patients with AF, PPP1R12C expression was increased 2-fold versus sinus rhythm controls (P=2.0×10-2; n=12 and 12 in each group) with >40% reduction in MLC2a phosphorylation (P=1.4×10-6; n=12 and 12 in each group). PPP1R12C-PP1c binding and PPP1R12C-MLC2a binding were significantly increased in AF (P=2.9×10-2 and 6.7×10-3, respectively; n=8 and 8 in each group). In vitro studies utilizing drug BDP5290, which inhibits T560-PPP1R12C phosphorylation, demonstrated increased PPP1R12C binding with both PP1c and MLC2a and dephosphorylation of MLC2a. Mice treated with lentiviral PPP1R12C vector demonstrated a 150% increase in left atrial size versus controls (P=5.0×10-6; n=12, 8, and 12), with reduced atrial strain and atrial ejection fraction. Pacing-induced AF in mice treated with lentiviral PPP1R12C vector was significantly higher than in controls (P=1.8×10-2 and 4.1×10-2, respectively; n=6, 6, and 5). Patients with AF exhibit increased levels of PPP1R12C protein compared with controls. PPP1R12C overexpression in mice increases PP1c targeting to MLC2a and causes MLC2a dephosphorylation, which reduces atrial contractility and increases AF inducibility. These findings suggest that PP1 regulation of sarcomere function at MLC2a is a key determinant of atrial contractility in AF.

TNFSF14/LIGHT promotes cardiac fibrosis and atrial fibrillation vulnerability via PI3Kγ/SGK1 pathway-dependent M2 macrophage polarisation

BackgroundTumour necrosis factor superfamily protein 14 (TNFSF14), also called LIGHT, is an important regulator of immunological and fibrosis diseases. However, its specific involvement in cardiac fibrosis and atrial fibrillation (AF) has not been fully elucidated. The objective of this study is to examine the influence of LIGHT on the development of myocardial fibrosis and AF.MethodsPCR arrays of peripheral blood mononuclear cells (PBMCs) from patients with AF and sinus rhythm was used to identify the dominant differentially expressed genes, followed by ELISA to evaluate its serum protein levels. Morphological, functional, and electrophysiological changes in the heart were detected in vivo after the tail intravenous injection of recombinant LIGHT (rLIGHT) in mice for 4 weeks. rLIGHT was used to stimulate bone marrow-derived macrophages (BMDMs) to prepare a macrophage-conditioned medium (MCM) in vitro. Then, the MCM was used to culture mouse cardiac fibroblasts (CFs). The expression of relevant proteins and genes was determined using qRT-PCR, western blotting, and immunostaining.ResultsThe mRNA levels of LIGHT and TNFRSF14 were higher in the PBMCs of patients with AF than in those of the healthy controls. Additionally, the serum protein levels of LIGHT were higher in patients with AF than those in the healthy controls and were correlated with left atrial reverse remodelling. Furthermore, we demonstrated that rLIGHT injection promoted macrophage infiltration and M2 polarisation in the heart, in addition to promoting atrial fibrosis and AF inducibility in vivo, as detected with MASSON staining and atrial burst pacing respectively. RNA sequencing of heart samples revealed that the PI3Kγ/SGK1 pathway may participate in these pathological processes. Therefore, we confirmed the hypothesis that rLIGHT promotes BMDM M2 polarisation and TGB-β1 secretion, and that this process can be inhibited by PI3Kγ and SGK1 inhibitors in vitro. Meanwhile, increased collagen synthesis and myofibroblast transition were observed in LIGHT-stimulated MCM-cultured CFs and were ameliorated in the groups treated with PI3Kγ and SGK1 inhibitors.ConclusionLIGHT protein levels in peripheral blood can be used as a prognostic marker for AF and to evaluate its severity. LIGHT promotes cardiac fibrosis and AF inducibility by promoting macrophage M2 polarisation, wherein PI3Kγ and SGK1 activation is indispensable.

Incidence, risk factors, and outcomes of atrial functional mitral regurgitation in patients with atrial fibrillation or sinus rhythm.

Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on incident AFMR are scarce. We aimed to study the incidence, risk factors, and clinical significance of AFMR in AF or sinus rhythm (SR). Adults with new diagnosis of AF and adults in SR were identified. Patients with >mild MR at baseline, primary mitral disease, cardiomyopathy, left-sided valve disease, previous cardiac surgery, or with no follow-up echocardiogram were excluded. Diastolic dysfunction (DD) was indicated by ≥2/4 abnormal diastolic function parameters [mitral medial e', mitral medial E/e', tricuspid regurgitation velocity, left atrial volume index (LAVI)]. Overall, 1747 patients with AF and 29 623 in SR were included. Incidence rate of >mild AFMR was 2.6 per 100 person-year in new-onset AF and 0.7 per 100 person-year in SR, P < 0.001. AF remained associated with AFMR in a propensity score-matched analysis based on age, sex, and comorbidities between AF and SR [hazard ratio: 3.80 (95% confidence interval 3.04-4.76)]. Independent risk factors associated with incident AFMR were age ≥65 years, female sex, LAVI, and DD in both AF and SR, in addition to rate (vs. rhythm) control in AF. Incident AFMR was independently associated with all-cause death in both groups (both P < 0.001). AF conferred a three-fold increase in the risk of incident AFMR. DD, older age, left atrial size, and female sex were independent risk factors in both SR and AF, while rhythm control was protective. AFMR was universally associated with worse mortality.

Research on the Internal Flow Field of Left Atrial Appendage and Stroke Risk Assessment with Different Blood Models.

Extant clinical research has underscored that patients suffering from atrial fibrillation (AF) bear an elevated risk for stroke, predominantly driven by the formation of thrombus in the left atrial appendage (LAA). As such, accurately identifying those at an increased risk of thrombosis becomes paramount to facilitate timely and effective treatment. This study was designed to shed light on the mechanisms underlying thrombus formation in the LAA by employing three-dimensional (3D) left atrium (LA) models of AF patients, which were constructed based on Computed Tomography (CT) imaging. The distinct benefits of Computational Fluid Dynamics (CFD) were leveraged to simulate the blood flow field within the LA, using three distinct blood flow models, both under AF and sinus rhythm (SR) conditions. The potential risk of thrombus formation was evaluated by analyzing the Relative Residence Time (RRT) and Endothelial Cell Activation Potential (ECAP) values. The results gleaned from this study affirm that all three blood flow models align with extant clinical guidelines, thereby enabling an effective prediction of thrombosis risk. However, noteworthy differences emerged when comparing the intricacies of the flow field and thrombosis risk across the three models. The single-phase non-Newtonian blood flow model resulted in comparatively lower residence times for blood within the LA and lower values for the Oscillatory Shear Index (OSI), RRT, and ECAP within the LAA. These findings suggest a reduced thrombosis risk. Conversely, the two-phase non-Newtonian blood flow model exhibited a higher residence time for blood and elevated RRT value within the LAA, suggesting an increased risk for thrombosis.

Effect of clinic-based single-lead electrocardiogram rhythm assessment on oral anticoagulation prescriptions in patients with previously diagnosed atrial fibrillation.

Despite benefits of oral anticoagulation (OAC), many individuals with diagnosed atrial fibrillation (AF) do not receive OAC. The purpose of this study was to assess whether cardiac rhythm assessment for AF impacted use of OAC in patients with previously diagnosed AF. VITAL-AF was a cluster randomized controlled trial conducted in 16 primary care practices assessing the efficacy of AF rhythm assessment with single-lead electrocardiogram in routine care. Patients 65 years and older were offered rhythm assessment at visits. In this secondary analysis, we evaluated rhythm assessment uptake and compared initiation and discontinuation of OAC in patients with previously diagnosed AF from intervention and control arms over 1 year. The study included 4593 patients with previously diagnosed AF (2250 intervention; 2343 control). In the intervention arm, 2022 (89.9%) completed rhythm assessment (median 2 visits with rhythm assessment) and 40.1% had ≥1 "Possible AF" result. Initiation of OAC was similar in the intervention (17.7%) and control (19.1%) arms but was influenced by the rhythm assessment result: higher with a "Possible AF" (26.1%; adjusted odds ratio [aOR] 1.62; 95% confidence interval [CI] 1.04-2.51), and lower with a "Normal" result (9.9%; aOR 0.45; 95% CI 0.29-0.71) compared to control. OAC discontinuation was similar in the intervention (6.3%) and control (7.2%) arms, with lower discontinuation with a "Possible AF" result (3.8%; aOR 0.51; 95% CI 0.32-0.81). Including patients with previously diagnosed AF in a point-of-care rhythm assessment strategy did not increase overall OAC use compared to the control arm. However, the rhythm assessment result influenced both initiation and discontinuation of OAC.

Cardio-Ankle Vascular Index and Left Atrial Reverse Remodeling After Ablation for Atrial Fibrillation.

Arterial stiffness has been reported to cause left atrial (LA) remodeling due to increased left ventricular filling pressure, resulting in atrial fibrillation (AF). This study aimed to evaluate the association between LA reverse remodeling (LARR) after AF ablation and cardio-ankle vascular index (CAVI), an indicator of arterial stiffness.This study included 333 patients with AF (171 with paroxysmal AF and 162 with nonparoxysmal AF) and LA enlargement (LA volume index ≥ 34 mL/m2) who underwent AF ablation between December 2008 and July 2021. CAVI was evaluated preoperatively during AF (n = 155, 46.5%) or sinus rhythm (n = 178, 53.5%). Participants were divided into groups with LARR (n = 133, 39.9%) and without LARR (n = 200, 60.1%) according to whether the degree of decrease in LA volume index on transthoracic echocardiography 6 months after ablation was ≥ 15% or < 15%, respectively.Sinus rhythm was maintained in 168 (50.5%) patients within 3-6 months after the index procedure. Univariate analysis revealed that preoperative CAVI (7.80 ± 1.22 versus 8.57 ± 1.09, P < 0.001) was significantly lower, and the maintenance of sinus rhythm (61.6% versus 43.0%, P = 0.0011) was higher in the group with LARR. Multivariate logistic regression analysis revealed that preoperative CAVI was independently associated with LARR (odds ratio, 0.60, 95% confidence interval, 0.46-0.78, P < 0.001).In patients with AF and LA enlargement, CAVI is independently associated with LA reverse remodeling after catheter ablation.

Impaired Renal Vein Flow in Atrial Fibrillation: A Potential Risk for Renal Dysfunction.

BACKGROUND Atrial fibrillation (AF) is one of the most common heart rhythm disorders. Identification and early treatment of AF risk factors can improve mortality and morbidity rates. This study aimed to compare the renal venous stasis index (RVSI) and intra-renal venous flow (IRVF) patterns evaluated by intra-renal Doppler ultrasonography in patients with AF and sinus rhythm (SR). MATERIAL AND METHODS A total of 68 patients, 34 with AF (lasting >12 months AF) and 34 with SR (no previous diagnosis of AF and no AF attack in 24-h Holter monitoring) were included in the study. The RVSI was calculated, and the IRVF patterns were determined using intra-renal Doppler ultrasonography. High RVSI was defined as >0.12 RVSI. In addition, echocardiography and a 6-min walk test were performed. A model including diabetes mellitus, hypertension, creatine, Pro-BNP, left ventricular ejection fraction, presence of AF, and systolic pulmonary artery pressure was created to evaluate the effects of variables on high RVSI. RESULTS The RVSI value was significantly higher in patients with AF than in those with SR (P=0.004). The SR group exhibited a higher prevalence of the continuous flow pattern, which is one of the IRVF patterns (P=0.015). In contrast, the biphasic flow pattern was observed more frequently in patients with AF (P=0.003). The presence of AF was found to predict the high RVSI (P=0.002, OR=14.134, 95% CI 2.083-71.277). CONCLUSIONS The presence of AF may affect the IRVF and cause an increase in RVSI.

Impact of atrial fibrillation on outcomes in asymptomatic severe aortic stenosis: a propensity-matched analysis.

Atrial fibrillation (AF) portends poor prognosis in patients with aortic stenosis (AS). This study aimed to study the association of AF vs. sinus rhythm (SR) with outcomes in asymptomatic severe AS during routine clinical practice. We identified 909 asymptomatic patients from 3,208 consecutive patients with aortic valve area ≤1.0 cm2 and left ventricular ejection fraction ≥50% at a tertiary academic center. Patients were grouped by rhythm at the time of transthoracic echocardiogram [SR: 820/909 (90%) and AF: 89/909 (10%)]. Propensity-matched analyses (2 SR:1 AF) matching 174 SR to 89 AF patients by age, sex, and clinical comorbidities were used to compare outcomes. In the propensity-matched cohort, median age (82 ± 8 vs. 81 ± 9 years, p = 0.31), sex distribution (male 58% vs. 52%, p = 0.30), and Charlson comorbidity index (4.0 vs. 3.0, p = 0.26) were not different in AF vs. SR. Median follow-up duration was 2.6 (IQR: 1.0-4.4) years. The 1-year rate of aortic valve replacement (AVR) was not different (AF: 32% vs. SR: 37%, p = 0.31). All-cause mortality was higher in AF [hazard ratio (HR): 1.68 (1.13-2.50), p = 0.009]. Independent predictors of mortality were age [HR: 1.92 (1.40-2.62), p < 0.001], Charlson comorbidity index [1.09 (1.03-1.15), p = 0.002], aortic valve peak velocity [HR: 1.87 (1.20-2.94), p = 0.006], stroke volume index [HR: 0.75 (0.60-0.93), p = 0.01], moderate or more mitral regurgitation [HR: 2.97 (1.43-6.19), p = 0.004], right ventricular systolic dysfunction [HR: 2.39 (1.29-4.43), p = 0.006], and time-dependent AVR [HR: 0.36 (0.19-0.65), p = 0.0008]. There was no significant interaction of AVR and rhythm (p = 0.57). Lower forward flow, right ventricular systolic dysfunction, and mitral regurgitation identified increased risk of subsequent mortality in asymptomatic patients with AF and AS. Additional studies of risk stratification of asymptomatic AS in AF vs. SR are needed.

Incident atrial functional mitral regurgitation in atrial fibrillation and sinus rhythm

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on its incidence, risk factors, and clinical outcomes are scarce. Objective We aimed to study the incidence, risk factors and clinical significance of AFMR, defined as &amp;gt;mild functional MR in the absence of more than mild left ventricle enlargement or dysfunction, in AF and sinus rhythm (SR). Methods Adults with a new diagnosis of AF between 2010–2021 who had a transthoracic echocardiogram (TTE) were identified (n=57,109). Similarly, adults with no diagnosis of AF who had a TTE between 2010–2021 were identified for comparison (n= 364,767). Patients with &amp;gt;mild MR at baseline, primary mitral valve disease, cardiomyopathy, ≥moderate aortic valve disease, current or previous low ejection fraction, enlarged left ventricle, cardiac devices, previous cardiac surgeries, or with no follow up TTE ≥6 months from baseline were excluded. Furthermore, patients with AF had to have a TTE within 1 month of AF diagnosis. The presence of ≥2 of 4 abnormal diastolic function parameters [mitral septal e’ &amp;lt;0.07 m/sec, mitral septal E/e’ &amp;gt;15 in SR and &amp;gt;11 in AF, TR velocity &amp;gt;2.80 m/sec, left atrial volume index &amp;gt;34 ml/m2] was determined. Cox proportional hazards regression was used to determine risk factors associated with incident AFMR and all-cause death. Patients without the event of interest were censored at last follow up. Patients who developed &amp;gt;mild MR of other types (primary or functional ventricular) were censored at that time. Results Overall, 1,747 (median age 67 years; 34% females) patients with AF and 29,623 (median age 59; 51% females) in SR were included. Incident AFMR occurred in 167 patients with AF over median 3.1 (IQR 1.6–5.1) years [incidence rate of 2.6 per 100-person year] and in 780 patients in SR over median 3.1 (IQR 1.5–5.8) years [incidence rate 0.7 per 100-person year] (Figure 1). AF remained associated with AFMR after adjusting to confounding factors [age ≥65, female sex, ≥2 abnormal diastolic function parameters, and low hemoglobin; adjusted HR 3.23 (2.71–3.85)]. Independent risk factors associated with incident AFMR in AF were age ≥65, female sex, persistent AF, and ≥2 abnormal diastolic function parameters, whereas successful rhythm control without recurrence was a protective factor (Figure 2a). Risk factors for AFMR in SR were age ≥65 years, female sex, presence of ≥2 abnormal diastolic function parameters, and low hemoglobin (Figure 2a). Incident AFMR was independently associated with all-cause death in both AF and SR (Figure 2b). Conclusions AF confers more than 3-fold increase in the risk of AFMR. Diastolic dysfunction, older age, and female sex were independent risk factors for incident AFMR in both SR and AF. Paroxysmal AF and successful rhythm control were protective factors against AFMR in AF. AFMR is universally associated with worse mortality.

Identifying Patients at High Risk of Left Atrial Appendage Thrombus Before Cardioversion: The CLOTS-AF Score.

Background Transesophageal echocardiography-guided direct cardioversion is recommended in patients who are inadequately anticoagulated due to perceived risk of left atrial appendage thrombus (LAAT); however, LAAT risk factors remain poorly defined. Methods and Results We evaluated clinical and transthoracic echocardiographic parameters to predict LAAT risk in consecutive patients with atrial fibrillation (AF)/atrial flutter undergoing transesophageal echocardiography before cardioversion between 2002 and 2022. Regression analysis identified predictors of LAAT, combined to create the novel CLOTS-AF risk score (comprising clinical and echocardiographic LAAT predictors), which was developed in the derivation cohort (70%) and validated in the remaining 30%. A total of 1001 patients (mean age, 62±13 years; 25% women; left ventricular ejection fraction, 49.8±14%) underwent transesophageal echocardiography, with LAAT identified in 140 of 1001 patients (14%) and dense spontaneous echo contrast precluding cardioversion in a further 75 patients (7.5%). AF duration, AF rhythm, creatinine, stroke, diabetes, and echocardiographic parameters were univariate LAAT predictors; age, female sex, body mass index, anticoagulant type, and duration were not (all P>0.05). CHADS2VASc, though significant on univariate analysis (P<0.001), was not significant after adjustment (P=0.12). The novel CLOTS-AF risk model comprised significant multivariable predictors categorized and weighted according to clinically relevant thresholds (Creatinine >1.5 mg/dL, Left ventricular ejection fraction <50%, Overload (left atrial volume index >34 mL/m2), Tricuspid Annular Plane Systolic Excursion (TAPSE) <17 mm, Stroke, and AF rhythm). The unweighted risk model had excellent predictive performance with an area under the curve of 0.820 (95% CI, 0.752-0.887). The weighted CLOTS-AF risk score maintained good predictive performance (AUC, 0.780) with an accuracy of 72%. Conclusions The incidence of LAAT or dense spontaneous echo contrast precluding cardioversion in patients with AF who are inadequately anticoagulated is 21%. Clinical and noninvasive echocardiographic parameters may identify patients at increased risk of LAAT better managed with a suitable period of anticoagulation before undertaking cardioversion.

Omega-3 Fatty Acids and Heart Rhythm, Rate, and Variability in Atrial Fibrillation.

Background Previous randomized control trials showed mixed results concerning the effect of omega-3 fatty acids (n-3 FAs) on atrial fibrillation (AF). The associations of n-3 FA blood levels with heart rhythm in patients with established AF are unknown. The goal of this study was to assess the associations of total and individual n-3 FA blood levels with AF type (paroxysmal versus nonparoxysmal), heart rate (HR), and HR variability in patients with AF. Methods and Results Total n-3 FAs, eicosapentaenoic acid, docosahexaenoic acid, docosapentaenoic acid, and alpha-linolenic acid blood levels were determined in 1969 patients with known AF from the SWISS-AF (Swiss Atrial Fibrillation cohort). Individual and total n-3 FAs were correlated with type of AF, HR, and HR variability using standard logistic and linear regression, adjusted for potential confounders. Only a mild association with nonparoxysmal AF was found with total n-3 FA (odds ratio [OR], 0.97 [95% CI, 0.89-1.05]) and docosahexaenoic acid (OR, 0.93 [95% CI, 0.82-1.06]), whereas other individual n-3 FAs showed no association with nonparoxysmal AF. Higher total n-3 FAs (estimate 0.99 [95% CI, 0.98-1.00]) and higher docosahexaenoic acid (0.99 [95% CI, 0.97-1.00]) tended to be associated with slower HR in multivariate analysis. Docosapentaenoic acid was associated with a lower HR variability triangular index (0.94 [95% CI, 0.89-0.99]). Conclusions We found no strong evidence for an association of n-3 FA blood levels with AF type, but higher total n-3 FA levels and docosahexaenoic acid might correlate with lower HR, and docosapentaenoic acid with a lower HR variability triangular index.

Accuracy of a Standalone Atrial Fibrillation Detection Algorithm Added to a Popular Wristband and Smartwatch: Prospective Diagnostic Accuracy Study

Silent paroxysmal atrial fibrillation (AF) may be difficult to diagnose, and AF burden is hard to establish. In contrast to conventional diagnostic devices, photoplethysmography (PPG)-driven smartwatches or wristbands allow for long-term continuous heart rhythm assessment. However, most smartwatches lack an integrated PPG-AF algorithm. Adding a standalone PPG-AF algorithm to these wrist devices might open new possibilities for AF screening and burden assessment. The aim of this study was to assess the accuracy of a well-known standalone PPG-AF detection algorithm added to a popular wristband and smartwatch, with regard to discriminating AF and sinus rhythm, in a group of patients with AF before and after cardioversion (CV). Consecutive consenting patients with AF admitted for CV in a large academic hospital in Amsterdam, the Netherlands, were asked to wear a Biostrap wristband or Fitbit Ionic smartwatch with Fibricheck algorithm add-on surrounding the procedure. A set of 1-min PPG measurements and 12-lead reference electrocardiograms was obtained before and after CV. Rhythm assessment by the PPG device-software combination was compared with the 12-lead electrocardiogram. A total of 78 patients were included in the Biostrap-Fibricheck cohort (156 measurement sets) and 73 patients in the Fitbit-Fibricheck cohort (143 measurement sets). Of the measurement sets, 19/156 (12%) and 7/143 (5%), respectively, were not classifiable by the PPG algorithm due to bad quality. The diagnostic performance in terms of sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 98%, 96%, 96%, 99%, 97%, and 97%, 100%, 100%, 97%, and 99%, respectively, at an AF prevalence of ~50%. This study demonstrates that the addition of a well-known standalone PPG-AF detection algorithm to a popular PPG smartwatch and wristband without integrated algorithm yields a high accuracy for the detection of AF, with an acceptable unclassifiable rate, in a semicontrolled environment.

Cardiorespiratory fitness in individuals with and without atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Liaison Committee for Education, Research and Innovation in Central Norway (Samarbeidsorganet). Background Cardiorespiratory fitness is an important marker of cardiopulmonary health. The majority of published data is however based on healthy individuals. To improve clinical decisions and tailor exercise as treatment for patients with atrial fibrillation (AF), knowledge on impact of AF with and without other cardiovascular diseases (CVD) is essential. Purpose To explore impact of age, sex, presenting rhythm during cardiopulmonary exercise testing (CPET) and presence of other CVDs on directly measured peak oxygen uptake (VO2peak) in participants from a general health-survey with and without AF. Methods We used cross-sectional data from the HUNT4 Fitness Study, a subsample of the Trøndelag Health Study (HUNT, 2017-2019). All participants (n = 2548, 49 % women) completed a standardized CPET with ECG monitoring. We stratified participants into categories of validated AF diagnosis (yes/no) and whether the CPET was performed in sinus or AF rhythm among those with AF. As we did not have precise data for subtype of AF, cardiac rhythm under testing was used as a proxy for permanent/persistent AF or non-permanent AF. Other CVD (yes/no) was defined as stroke, coronary heart diseases, or heart failure, using validated diagnoses from hospital registries for those with AF and self-reported diagnoses for non-AF participants. We used a general linear model to investigate the differences in predicted means for VO2peak per category of AF, other CVD, age, and sex testing for interaction between covariates. Results In total, 355 participants had valid AF, and among them 139 performed CPET with AF rhythm (Table 1). Mean VO2peak was 26 and 35 mL/kg/min for women and men, respectively, with non-permanent AF (sinus) and 22 and 26 mL/kg/min for women and men with permanent AF. Results from the general linear model are shown as predicted means with 95% confidence and prediction intervals in Figure 1. VO2peak decreased with higher age for both women and men, with and without other CVD, and were generally lower for women than for men. For both sexes and categories of CVD, participants with permanent/persistent AF, and hence AF during CPET, had lower VO2peak than those with non-permanent AF tested in sinus rhythm, and those without AF. The difference was more prominent in the younger age groups. There were, however, only small differences between participants with non-permanent AF and those without AF. Predicted means for VO2peak were lower for women and men with other CVD than without other CVD. Conclusion VO2peak was similar in participants with AF performing CPET in sinus rhythm to those without AF when no other CVD was present. Permanent/persistent AF and presence of other CVDs were the two factors with the most negative impact on VO2peak for both men and women across age groups.