Subclinical and Asymptomatic Atrial Fibrillation: Current Evidence and Unsolved Questions in Clinical Practice

Effectiveness and Safety of Edoxaban in the Routine Clinical Care of Atrial Fibrillation Patients in Brazil: Prospective 1-Year Follow-Up Study - EdoBRA

BACKGROUND

Edoxaban, an orally administered anticoagulant, has been shown to be safe and effective in preventing stroke in atrial fibrillation (AF) patients. Given its widespread use since approval, evaluating edoxaban's real-world performance in the Brazilian clinical context is crucial.

OBJECTIVE

The study aimed to report the one-year safety and effectiveness of edoxaban in AF patients in Brazil.

METHODS

EdoBRA is a multi-center, prospective, observational investigation conducted across 30 Brazilian research sites. Bleeding events were considered as safety measures and cardiovascular events were considered for effectiveness measures. Descriptive analyses were performed. Kaplan-Meier curves were generated for time-to-event analysis and a 95% confidence interval was used as appropriate.

RESULTS

Among the 705 enrolled participants, 590 were included in the analysis for having at least one follow-up or one reported event. Mean (±SD) CHA2DS2-VASc risk score was 3 (3.3 ± 1.6) and the mean HAS-BLED risk score was 2 (1.8 ± 1.2). During the one-year follow-up period, nine major bleedings events were reported, including five cases of gastrointestinal bleeding (IP 0.85 [95% CI =0.82; 0.88]). Among the cardiovascular events recorded (N = 68), there were four stroke events (IP 0.68 [CI 95% 0.65;0.71]), one transient ischemic attack (IP 0.17 [CI 95% (0.16;0.18]) and 1 event was Venous Thromboembolic Events (IP 0.17 [CI 95% (0.16;0.18]). No systemic embolic event was exhibited by any patient.

CONCLUSION

In an elderly population with several comorbidities routinely treated with edoxaban for AF, the rates of cardiovascular event and major bleeding were low.

Evolution in electrophysiology 100 years after Einthoven: translational and computational innovations in rhythm control of atrial fibrillation

In 1924, the Dutch physiologist Willem Einthoven received the Nobel Prize in Physiology or Medicine for his discovery of the mechanism of the electrocardiogram (ECG). Anno 2024, the ECG is commonly used as a diagnostic tool in cardiology. In the paper 'Le Télécardiogramme', Einthoven described the first recording of the now most common cardiac arrhythmia: atrial fibrillation (AF). The treatment of AF includes rhythm control, aiming to alleviate symptoms and improve quality of life. Recent studies found that early rhythm control might additionally improve clinical outcomes. However, current therapeutic options have suboptimal efficacy and safety, highlighting a need for better rhythm-control strategies. In this review, we address the challenges related to antiarrhythmic drugs (AADs) and catheter ablation for rhythm control of AF, including significant recurrence rates and adverse side effects such as pro-arrhythmia. Furthermore, we discuss potential solutions to these challenges including novel tools, such as atrial-specific AADs and digital-twin-guided AF ablation. In particular, digital twins are a promising method to integrate a wide range of clinical data to address the heterogeneity in AF mechanisms. This may enable a more mechanism-based tailored approach that may overcome the limitations of previous precision medicine approaches based on individual biomarkers. However, several translational challenges need to be addressed before digital twins can be routinely applied in clinical practice, which we discuss at the end of this narrative review. Ultimately, the significant advances in the detection, understanding, and treatment of AF since its first ECG documentation are expected to help reduce the burden of this troublesome condition.

Considering User Experience and Behavioral Approaches in the Design of mHealth Interventions for Atrial Fibrillation: Systematic Review

BACKGROUND

Atrial fibrillation (AF) is a leading chronic cardiac disease associated with an increased risk of stroke, cardiac complications, and general mortality. Mobile health (mHealth) interventions, including wearable devices and apps, can aid in the detection, screening, and management of AF to improve patient outcomes. The inclusion of approaches that consider user experiences and behavior in the design of health care interventions can increase the usability of mHealth interventions, and hence, hopefully, yield an increase in positive outcomes in the lives of users.

OBJECTIVE

This study aims to show how research has considered user experiences and behavioral approaches in designing mHealth interventions for AF detection, screening, and management; the phases of designing complex interventions from the UK Medical Research Council (MRC) were referenced: namely, identification, development, feasibility, evaluation, and implementation.

METHODS

Studies published until September 7, 2022, that examined user experiences and behavioral approaches associated with mHealth interventions in the context of AF were extracted from multiple databases. The PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines were used.

RESULTS

A total of 2219 records were extracted, with only 55 records reporting on usability, user experiences, or behavioral approaches more widely for designing mHealth interventions in the context of AF. When mapping the studies onto the phases of the UK MRC's guidance for developing and evaluating complex interventions, the following was found: in the identification phase, there were significant differences between the needs of patients and health care workers. In the development phase, user perspectives guided the iterative development of apps, interfaces, and intervention protocols in 4 studies. Most studies (43/55, 78%) assessed the usability of interventions in the feasibility phase as an outcome, although the data collection tools were not designed together with users and stakeholders. Studies that examined the evaluation and implementation phase entailed reporting on challenges in user participation, acceptance, and workflows that could not be captured by studies in the previous phases. To realize the envisaged human behavior intended through treatment, review results highlight the scant inclusion of behavior change approaches for mHealth interventions across multiple levels of sociotechnical health care systems. While interventions at the level of the individual (micro) and the level of communities (meso) were found in the studies reviewed, no studies were found intervening at societal levels (macro). Studies also failed to consider the temporal variation of user goals and feedback in the design of long-term behavioral interventions.

CONCLUSIONS

In this systematic review, we proposed 2 contributions: first, mapping studies to different phases of the MRC framework for developing and evaluating complex interventions, and second, mapping behavioral approaches to different levels of health care systems. Finally, we discuss the wider implications of our results in guiding future mHealth research.

Global burden of atrial fibrillation/atrial flutter and its attributable risk factors from 1990 to 2021

AIMS

To devise effective preventive measures, a profound understanding of the evolving patterns and trends in atrial fibrillation (AF) and atrial flutter (AFL) burdens is pivotal. Our study was designed to quantify the burden and delineate the risk factors associated with AF and AFL across 204 countries and territories spanning 1990-2021.

METHODS AND RESULTS

Data pertaining to AF and AFL were sourced from the Global Burden of Disease Study 2021. The burden of AF/AFL was evaluated using metrics such as incidence, disability-adjusted life years (DALYs), deaths, and their corresponding age-standardized rates (ASRs), stratified by age, sex, socio-demographic index (SDI), and human development index (HDI). The estimated annual percentage change was employed to quantify changes in ASRs. Population attributable fractions were calculated to determine the proportional contributions of major risk factors to age-standardized AF/AFL deaths. This analysis encompassed the period from 1990 to 2021. Globally, in 2021, there were 4.48 million incident cases [95% uncertainty interval (UI): 3.61-5.70], 8.36 million DALYs (95% UI: 6.97-10.13) and 0.34 million deaths (95% UI: 0.29-0.37) attributed to AF/AFL. The AF/AFL burden in 2021, as well as its trends from 1990 to 2021, displayed substantial variations based on gender, SDI quintiles, and geographical regions. High systolic blood pressure emerged as the leading contributor to age-standardized AF/AFL incidence, prevalence, death, and DALY rate globally among all potential risk factors, followed closely by high body mass index.

CONCLUSION

Our study underscores the enduring significance of AF/AFL as a prominent public health concern worldwide, marked by profound regional and national variations. Despite the substantial potential for prevention and management of AF/AFL, there is a pressing imperative to adopt more cost-effective strategies and interventions to target modifiable risk factors, particularly in areas where the burden of AF/AFL is high or escalating.

[Anticoagulation instauration in device-detected subclinical atrial fibrillation: what impact does it have on outcomes?]

No aplica

Asymptomatic atrial fibrillation among hospitalized patients: clinical correlates and in-hospital outcomes in Improving Care for Cardiovascular Disease in China-Atrial Fibrillation

AIMS

The clinical correlates and outcomes of asymptomatic atrial fibrillation (AF) in hospitalized patients are largely unknown. We aimed to investigate the clinical correlates and in-hospital outcomes of asymptomatic AF in hospitalized Chinese patients.

METHODS AND RESULTS

We conducted a cross-sectional registry study of inpatients with AF enrolled in the Improving Care for Cardiovascular Disease in China-Atrial Fibrillation Project between February 2015 and December 2019. We investigated the clinical characteristics of asymptomatic AF and the association between the clinical correlates and the in-hospital outcomes of asymptomatic AF. Asymptomatic and symptomatic AF were defined according to the European Heart Rhythm Association score. Asymptomatic patients were more commonly males (56.3%) and had more comorbidities such as hypertension (57.4%), diabetes mellitus (18.6%), peripheral artery disease (PAD; 2.3%), coronary artery disease (55.5%), previous history of stroke/transient ischaemic attack (TIA; 17.9%), and myocardial infarction (MI; 5.4%); however, they had less prevalent heart failure (9.6%) or left ventricular ejection fractions ≤40% (7.3%). Asymptomatic patients were more often hospitalized with a non-AF diagnosis as the main diagnosis and were more commonly first diagnosed with AF (23.9%) and long-standing persistent/permanent AF (17.0%). The independent determinants of asymptomatic presentation were male sex, long-standing persistent AF/permanent AF, previous history of stroke/TIA, MI, PAD, and previous treatment with anti-platelet drugs. The incidence of in-hospital clinical events such as all-cause death, ischaemic stroke/TIA, and acute coronary syndrome (ACS) was higher in asymptomatic patients than in symptomatic patients, and asymptomatic clinical status was an independent risk factor for in-hospital all-cause death, ischaemic stroke/TIA, and ACS.

CONCLUSION

Asymptomatic AF is common among hospitalized patients with AF. Asymptomatic clinical status is associated with male sex, comorbidities, and a higher risk of in-hospital outcomes. The adoption of effective management strategies for patients with AF should not be solely based on clinical symptoms.

Beat-to-beat finger photoplethysmography in atrial fibrillation patients undergoing electrical cardioversion

Atrial fibrillation (AF)-induced peripheral microcirculatory alterations have poorly been investigated. The present study aims to expand current knowledge through a beat-to-beat analysis of non-invasive finger photoplethysmography (PPG) in AF patients restoring sinus rhythm by electrical cardioversion (ECV). Continuous non-invasive arterial blood pressure and left middle finger PPG pulse oximetry waveform (POW) signals were continuously recorded before and after elective ECV of consecutive AF or atrial flutter (AFL) patients. The main metrics (mean, standard deviation, coefficient of variation), as well as a beat-to-beat analysis of the pulse pressure (PP) and POW beat-averaged value (aPOW), were computed to compare pre- and post-ECV phases. 53 patients (mean age 69 ± 8 years, 79% males) were enrolled; cardioversion was successful in restoring SR in 51 (96%) and signal post-processing was feasible in 46 (87%) patients. In front of a non-significant difference in mean PP (pre-ECV: 51.96 ± 13.25, post-ECV: 49.58 ± 10.41 mmHg; p = 0.45), mean aPOW significantly increased after SR restoration (pre-ECV: 0.39 ± 0.09, post-ECV: 0.44 ± 0.06 a.u.; p < 0.001). Moreover, at beat-to-beat analysis linear regression yielded significantly different slope (m) for the PP (RR) relationship compared to aPOW(RR) [PP(RR): 0.43 ± 0.18; aPOW(RR): 1.06 ± 0.17; p < 0.001]. Long (> 95th percentile) and short (< 5th percentile) RR intervals were significantly more irregular in the pre-ECV phases for both PP and aPOW; however, aPOW signal suffered more fluctuations compared to PP (p < 0.001 in both phases). Present findings suggest that AF-related hemodynamic alterations are more manifest at the peripheral (aPOW) rather than at the upstream macrocirculatory level (PP). Restoring sinus rhythm increases mean peripheral microvascular perfusion and decreases variability of the microvascular hemodynamic signals. Future dedicated studies are required to determine if AF-induced peripheral microvascular alterations might relate to long-term prognostic effects.

[Asymptomatic atrial fibrillation : Screening and therapy]

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide and poses a significant burden to the health care system. AF screening of the general population or of a specific higher-risk population could not only lead to earlier detection of AF but also to a prompt initiation of an adequate therapy to prevent complications such as stroke or death and consecutively to a potential reduction of health care costs, especially in asymptomatic AF patients. To conduct screening programs, accessible new technology devices such as "wearables", smartwatches, and implantable event recorders provide an innovative solution. However, as data regarding screening are inconclusive, routine AF screening of the population is currently not recommended by the European Society of Cardiology. Recently published studies have indicated that anticoagulation and early rhythm control of asymptomatic AF could avoid occurrence of clinical endpoints. This article reports on the scientific results of the current literature as well as gaps of evidence and discusses possible treatment options of asymptomatic AF.

Analysis of Pharmacy Cardiac Optimization Clinic for Patients with New Onset Atrial Fibrillation Detected via Cardiac Implantable Electronic Device Clinic

For patients with cardiac implantable electronic devices (CIEDs), arrythmias such as atrial fibrillation (AF) can be detected and actions taken to rapidly assess and initiate treatment where appropriate. Actions include timely initiation of anticoagulation, review of blood pressure, and optimization of cholesterol/lipids to prevent unfavorable outcomes, such as stroke and other cardiovascular complications. Delays to initiating anticoagulation can have devastating consequences. We sought to implement a virtual clinic, where a pharmacist reviews patient referrals from a CIED clinic after detecting AF from the CIED. Anticoagulation choice is determined by patient-specific factors, and a shared patient-provider decision to start oral anticoagulation is made. In addition, blood pressure readings and medications are assessed with lipid-lowering therapies for optimization. A total of 315 patients have been admitted through this clinic and anticoagulated over a two-year span; in addition, 322 successful interventions were made for optimization of cardiac therapy. Rapid initiation of anticoagulation within five days of referral was likely to have reduced unfavorable outcomes, such as stroke and other cardiovascular optimizations, leading to improved patient outcomes.

A Prognostic Score To Predict Atrial fibrillation Recurrence After External Electrical Cardioversion-SLAC Score

INTRODUCTION

Atrial fibrillation (AF) recurrence after a successful external electrical cardioversion (ECV) is common. Assessing an individual's risk of AF recurrence is a critical part of the treatment plan. We aimed to develop a prognostic prediction score to predict AF recurrence in AF patients who underwent successful ECV.

METHODS

A retrospective cohort study that included AF patients who underwent successful ECV was conducted with a primary outcome of AF recurrence at 6 months. Logistic regression analysis was done to identify variables, and a prognostic prediction score was created and internally validated.

RESULTS

Four prognostic predictors were identified, including the type of AF, persistent AF (1 point) and long-standing persistent AF (4 points), previous cardioversion (1 point), stroke/transient ischemic attack (3 points), and left atrial volume index ≥40 mL/m 2 (6 points). The total score of 14 was further divided into 3 risk groups; low-risk (0-2 points), moderate-risk (3-7 points), and high-risk (8-14 points). The positive likelihood ratio for a moderate-risk patient was 2.08 (95% CI, 1.64-2.63) and for a high-risk patient was 7.90 (95% CI, 2.48-25.17). The score showed good discrimination power with the c-statistic of 0.74 (95% CI, 0.69-0.79).

CONCLUSIONS

A simple prognostic prediction score for AF recurrence after successful ECV was created with a promising internally validated discrimination power. An external assessment of its usefulness as a tool to identify patients with low, moderate, and high risk for AF recurrence is warranted.

Atrioventricular Synchronization for Detection of Atrial Fibrillation and Flutter in One to Twelve ECG Leads Using a Dense Neural Network Classifier

This study investigates the use of atrioventricular (AV) synchronization as an important diagnostic criterion for atrial fibrillation and flutter (AF) using one to twelve ECG leads. Heart rate, lead-specific AV conduction time, and P-/f-wave amplitude were evaluated by three representative ECG metrics (mean value, standard deviation), namely RR-interval (RRi-mean, RRi-std), PQ-interval (PQi-mean, PQI-std), and PQ-amplitude (PQa-mean, PQa-std), in 71,545 standard 12-lead ECG records from the six largest PhysioNet CinC Challenge 2021 databases. Two rhythm classes were considered (AF, non-AF), randomly assigning records into training (70%), validation (20%), and test (10%) datasets. In a grid search of 19, 55, and 83 dense neural network (DenseNet) architectures and five independent training runs, we optimized models for one-lead, six-lead (chest or limb), and twelve-lead input features. Lead-set performance and SHapley Additive exPlanations (SHAP) input feature importance were evaluated on the test set. Optimal DenseNet architectures with the number of neurons in sequential [1st, 2nd, 3rd] hidden layers were assessed for sensitivity and specificity: DenseNet [16,16,0] with primary leads (I or II) had 87.9-88.3 and 90.5-91.5%; DenseNet [32,32,32] with six limb leads had 90.7 and 94.2%; DenseNet [32,32,4] with six chest leads had 92.1 and 93.2%; and DenseNet [128,8,8] with all 12 leads had 91.8 and 95.8%, indicating sensitivity and specificity values, respectively. Mean SHAP values on the entire test set highlighted the importance of RRi-mean (100%), RR-std (84%), and atrial synchronization (40-60%) for the PQa-mean (aVR, I), PQi-std (V2, aVF, II), and PQi-mean (aVL, aVR). Our focus on finding the strongest AV synchronization predictors of AF in 12-lead ECGs would lead to a comprehensive understanding of the decision-making process in advanced neural network classifiers. DenseNet self-learned to rely on a few ECG behavioral characteristics: first, characteristics usually associated with AF conduction such as rapid heart rate, enhanced heart rate variability, and large PQ-interval deviation in V2 and inferior leads (aVF, II); second, characteristics related to a typical P-wave pattern in sinus rhythm, which is best distinguished from AF by the earliest negative P-peak deflection of the right atrium in the lead (aVR) and late positive left atrial deflection in lateral leads (I, aVL). Our results on lead-selection and feature-selection practices for AF detection should be considered for one- to twelve-lead ECG signal processing settings, particularly those measuring heart rate, AV conduction times, and P-/f-wave amplitudes. Performances are limited to the AF diagnostic potential of these three metrics. SHAP value importance can be used in combination with a human expert's ECG interpretation to change the focus from a broad observation of 12-lead ECG morphology to focusing on the few AV synchronization findings strongly predictive of AF or non-AF arrhythmias. Our results are representative of AV synchronization findings across a broad taxonomy of cardiac arrhythmias in large 12-lead ECG databases.

Association of Catheter Ablation and Reduced Incidence of Dementia among Patients with Atrial Fibrillation during Long-Term Follow-Up: A Systematic Review and Meta-Analysis of Observational Studies

Background: Atrial fibrillation (AF) is independently associated with the onset of cognitive decline/dementia. AF catheter ablation (AFCA) is the most effective treatment strategy in terms of sinus rhythm maintenance, but its effects on dementia prevention remain under investigation. The aim of the present study was to perform a systematic review and meta-analysis of the presently available studies exploring the effect of AFCA on dementia occurrence. Methods: PubMed/MEDLINE databases were screened for articles through 14 March 2022 reporting adjusted time-to-event outcome data comparing AFCA and non-AFCA cohorts in terms of de novo dementia occurrence. A random effect meta-analysis was performed to estimate the meta-analytic hazard ratio (HR) of dementia occurrence in AFCA vs. non-AFCA cohorts, as well as the meta-analytic incidence rate of dementia in the non-AFCA cohort. Based on the aforementioned estimates, the number needed to treat (NNT), projected at median follow-up, was derived. Results: Four observational studies were included in the analysis, encompassing 40,146 patients (11,312 in the AFCA cohort; 28,834 in the non-AFCA cohort). AFCA conferred a significant protection to the development of dementia with an overall HR of 0.52 (95% CI 0.35–0.76). The incidence rate of dementia in the non-AFCA group was 1.12 events per 100 person-year (95% CI 0.47–2.67). The derived NNT projected to the median follow-up (4.5 years) was 41. Conclusion: AFCA is associated with a nearly 50% reduction in dementia occurrence during a median 4.5-year follow-up. Future randomized clinical trials are needed to reinforce these findings.

The utilization of atrial sensing dipole in single lead implantable cardioverter defibrillator for detection of new-onset atrial high-rate episodes or subclinical atrial fibrillation: A systematic review and meta-analysis

This meta-analysis aims to evaluate the performance of atrial sensing dipole in single lead implantable cardioverter defibrillator (VDD-ICD) recipients in particular diagnosing new-onset atrial high-rate episodes (AHREs) defined as rate threshold of 200 beats per minute, or subclinical atrial fibrillation (SCAF) defined as device-detected AF without symptoms. We comprehensively searched PubMed, Embase, and ClinicalTrials.gov. Studies comparing contemporary single- and dual-chamber ICD (VVI-/DDD-ICD) versus VDD-ICD were included. Restricted maximum likelihood method for random effect model and Mantel-Haenszel method for fixed effect model were used to estimate the effect size of new-onset AHREs, or SCAF detection in each group. Three prospective studies were identified and total of 991 participants were included. There were 330 (33.3%) in VDD-ICD and 661 (66.7%) in VVI-/DDD-ICD. Most (78%) participants were men. Median follow-up was from 365 days to 847 days. VDD-ICD has a higher likelihood of detecting AHREs or SCAF as compared to VVI-/DDD-ICD [(OR random effect : 2.6; 95% CI: 1.2, 5.8; p = .018); I-squared = 67.8%, p = .019]. This difference was more apparently seen in the comparison between VDD-ICD and VVI-ICD [(OR random effect: 3.8; 95% CI: 2.1, 6.6, p < .001), I-squared = 0.0%, p = .518]. The result is same as fixed effect. Rate of AHREs detection observed in VDD-ICD was not statistically different when compared to the only group with DDD-ICD from SENSE trial. In conclusion, this meta-analysis reveals that the use of floating atrial sensing dipole in VDD-ICD increases the detection of new-onset AHREs or SCAF when compared to VVI-ICD, with similar atrial sensing performance to DDD-ICD.

Application of Dense Neural Networks for Detection of Atrial Fibrillation and Ranking of Augmented ECG Feature Set

Considering the significant burden to patients and healthcare systems globally related to atrial fibrillation (AF) complications, the early AF diagnosis is of crucial importance. In the view of prominent perspectives for fast and accurate point-of-care arrhythmia detection, our study optimizes an artificial neural network (NN) classifier and ranks the importance of enhanced 137 diagnostic ECG features computed from time and frequency ECG signal representations of short single-lead strips available in 2017 Physionet/CinC Challenge database. Based on hyperparameters' grid search of densely connected NN layers, we derive the optimal topology with three layers and 128, 32, 4 neurons per layer (DenseNet-3@128-32-4), which presents maximal F1-scores for classification of Normal rhythms (0.883, 5076 strips), AF (0.825, 758 strips), Other rhythms (0.705, 2415 strips), Noise (0.618, 279 strips) and total F1 relevant to the CinC Challenge of 0.804, derived by five-fold cross-validation. DenseNet-3@128-32-4 performs equally well with 137 to 32 features and presents tolerable reduction by about 0.03 to 0.06 points for limited input sets, including 8 and 16 features, respectively. The feature reduction is linked to effective application of a comprehensive method for computation of the feature map importance based on the weights of the activated neurons through the total path from input to specific output in DenseNet. The detailed analysis of 20 top-ranked ECG features with greatest importance to the detection of each rhythm and overall of all rhythms reveals DenseNet decision-making process, noticeably corresponding to the cardiologists' diagnostic point of view.

Analysis of the ESC/EACTS 2020 Atrial Fibrillation Guidelines With Perioperative Implications

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide, with an individual lifetime risk of approximately 37% in the United States. Broadly defined as a supraventricular tachyarrhythmia with disorganized atrial activation, AF results in an increased risk of stroke, heart failure, valvular heart disease, and impaired quality of life, and confers a significant burden on the health of individuals and society. AF in the perioperative setting is common and a significant source of perioperative morbidity and mortality worldwide. The latest iteration of the European Society of Cardiology AF guidelines published in 2020 provide the clinician a valuable road map for the management of this arrythmia. This expert review will comprehensively analyze the 2020 European Society of Cardiology guidelines and provide perioperative management tools for the clinician.