Stroke prevention in atrial fibrillation

Differences between atrial fibrillation diagnosed before and after stroke: A large real-world cohort study

The clinical characteristics and long-term outcomes of patients with ischemic stroke (IS) and atrial fibrillation detected after stroke (AFDAS) have not been clearly established. Previous studies evaluating patients with AFDAS were limited by the low prescription rates of anticoagulants and short follow-up periods. Consecutive patients hospitalized for IS between 2014 and 2017 were identified from a National Health Insurance Research Database. The included patients were categorized into three groups: (1) known diagnosis of AF (KAF) before the index stroke, (2) AFDAS, and (3) without AF (non-AF). Univariable and multivariable Cox regression analyses were performed to estimate the hazard ratio (HR) for independent variables and recurrent IS, hemorrhagic stroke, or all-cause mortality. We identified 158,909 patients with IS of whom 16,699 (10.5%) had KAF and 7,826 (4.9%) had AFDAS. The patients with AFDAS were younger, more often male, and had lower CHA2DS2-VASc scores (3.8 ± 1.9 versus 4.9 ± 1.8, p < 0.001) than the patients with KAF. Anticoagulant treatment significantly reduced the risks of all outcomes. The standardized mortality rates were 40.4, 28.6, and 18.4 (per 100 person-years) for the patients with KAF, AFDAS, and non-AF, respectively. Compared with AFDAS, KAF was associated with lower risks of recurrent IS [hazard ratio (HR): 0.91, 95% confidence interval (CI): 0.86-0.97, p < 0.01] and hemorrhagic stroke (HR: 0.88, 95% CI: 0.79-0.99, p < 0.01) and a higher risk of all-cause mortality (HR: 1.11, 95% CI: 1.07-1.16, p < 0.001). The risks of recurrent IS and hemorrhagic stroke were higher and of all-cause mortality was lower for patients with AFDAS than with KAF. There is a strong need to refine treatment modalities to reduce the high mortality in patients with KAF and AFDAS.

Modelling anticoagulation and health-related quality of life in those with atrial fibrillation: a secondary analysis of AFFIRM

Associations of anticoagulation with primary endpoints in longitudinal studies are impacted by selection bias and time-varying covariates (e.g. comorbidities). We demonstrate how time-varying covariates and selection bias influence association estimates between anticoagulation and health-related quality of life (HRQoL) in patients with atrial fibrillation. We performed a secondary analysis of the Atrial Fibrillation Follow-up Investigation of Rhythm Management trial quality of life substudy. Dichotomized warfarin use was ascertained at the study baseline, 2 months later, and annually for up to 6 years. HRQoL was measured at every time point using a self-reported ordinal 5-point Likert-scale (lower score and lower odds ratio represents better health-related quality of life). Static and time-varying covariates were ascertained throughout the study period. Confounder-adjusted generalized mixed model and generalized estimating equation regressions were used to demonstrate traditional association estimates between anticoagulation and HRQoL. Inverse probability of treatment and censorship weights were used to ascertain the influence of time-varying confounding and selection bias. Age-stratified analysis (age ≥ 70 years) evaluated for effect modification. 656 individuals were included in the analysis, 601 on warfarin at baseline. The association of warfarin use with better HRQoL over time strengthened when accounting for time-varying confounding and selection bias (OR 0.30, 95% CI 0.14-0.55) compared to traditional analyses (OR 0.61, 95% CI 0.38-0.97), and was most pronounced in those ≥ 70 years upon stratified analysis. Anticoagulation is associated with higher HRQoL in patients with atrial fibrillation, with time-varying confounding and selection bias likely influencing longitudinal estimates in anticoagulation-HRQoL research.

Fair prediction of 2-year stroke risk in patients with atrial fibrillation

OBJECTIVE

This study aims to develop machine learning models that provide both accurate and equitable predictions of 2-year stroke risk for patients with atrial fibrillation across diverse racial groups.

MATERIALS AND METHODS

Our study utilized structured electronic health records (EHR) data from the All of Us Research Program. Machine learning models (LightGBM) were utilized to capture the relations between stroke risks and the predictors used by the widely recognized CHADS2 and CHA2DS2-VASc scores. We mitigated the racial disparity by creating a representative tuning set, customizing tuning criteria, and setting binary thresholds separately for subgroups. We constructed a hold-out test set that not only supports temporal validation but also includes a larger proportion of Black/African Americans for fairness validation.

RESULTS

Compared to the original CHADS2 and CHA2DS2-VASc scores, significant improvements were achieved by modeling their predictors using machine learning models (Area Under the Receiver Operating Characteristic curve from near 0.70 to above 0.80). Furthermore, applying our disparity mitigation strategies can effectively enhance model fairness compared to the conventional cross-validation approach.

DISCUSSION

Modeling CHADS2 and CHA2DS2-VASc risk factors with LightGBM and our disparity mitigation strategies achieved decent discriminative performance and excellent fairness performance. In addition, this approach can provide a complete interpretation of each predictor. These highlight its potential utility in clinical practice.

CONCLUSIONS

Our research presents a practical example of addressing clinical challenges through the All of Us Research Program data. The disparity mitigation framework we proposed is adaptable across various models and data modalities, demonstrating broad potential in clinical informatics.

Design and deployment of the STEEER-AF trial to evaluate and improve guideline adherence: a cluster-randomized trial by the European Society of Cardiology and European Heart Rhythm Association

AIMS

The aim is to describe the rationale, design, delivery, and baseline characteristics of the Stroke prevention and rhythm control Treatment: Evaluation of an Educational programme of the European society of cardiology in a cluster-Randomized trial in patients with Atrial Fibrillation (STEEER-AF) trial.

METHODS AND RESULTS

STEEER-AF is a pragmatic trial designed to objectively and robustly determine whether guidelines are adhered to in routine practice and evaluate a targeted educational programme for healthcare professionals. Seventy centres were randomized in six countries (France, Germany, Italy, Poland, Spain, and UK; 2022-23). The STEEER-AF centres recruited 1732 patients with a diagnosis of atrial fibrillation (AF), with a mean age of 68.9 years (SD 11.7), CHA2DS2-VASc score of 3.2 (SD 1.8), and 647 (37%) women. Eight hundred and forty-three patients (49%) were in AF at enrolment and 760 (44%) in sinus rhythm. Oral anticoagulant therapy was prescribed in 1543 patients (89%), with the majority receiving direct oral anticoagulants (1378; 89%). Previous cardioversion, antiarrhythmic drug therapy, or ablation was recorded in 836 patients (48.3%). Five hundred fifty-one patients (31.8%) were currently receiving an antiarrhythmic drug, and 446 (25.8%) were scheduled to receive a future cardioversion or ablation. The educational programme engaged 195 healthcare professionals across centres randomized to the intervention group, consisting of bespoke interactive online learning and reinforcement activities, supported by national expert trainers.

CONCLUSION

The STEEER-AF trial was successfully deployed across six European countries to investigate guideline adherence in real-world practice and evaluate if a structured educational programme for healthcare professionals can improve patient-level care.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT04396418.

Association of Left Atrial Appendage Morphology and Function With Stroke and Transient Ischemic Attack in Atrial Fibrillation Patients

We aimed to correlate left atrial appendage (LAA) structure and function with the history of stroke/transient ischemic attack (TIA) in patients with atrial fibrillation (AF). We analyzed the data of 649 patients with AF who were scheduled for catheter ablation. Patients underwent cardiac computed tomography and transesophageal echocardiography before ablation. The LAA morphologies depicted by cardiac computed tomography were categorized into 4 groups: cauliflower, chicken wing, swan, and windsock shapes. The mean age was 61.3 ± 10.5 years, 33.9% were women. The prevalence of stroke/TIA was 7.1%. After adjustment for the main risk factors, the LAA flow velocity ≤35.3 cm/s (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.09 to 4.61, p = 0.033) and the swan LAA shape (OR 2.69, 95% CI 0.96 to 6.86, p = 0.047) independently associated with a higher risk of stroke/TIA, whereas the windsock LAA morphology proved to be protective (OR 0.32, 95% CI 0.12 to 0.77, p = 0.017) compared with the cauliflower LAA shape. Comparing the differences between the LAA morphology groups, we measured a significantly smaller LAA orifice area (389.3 ± 137.7 mm2 in windsock vs 428.3 ± 158.9 ml in cauliflower, p = 0.021) and LAA volume (7.4 ± 3.0 mm2 in windsock vs 8.5 ± 4.8 mm2 in cauliflower, p = 0.012) in patients with windsock LAA morphology, whereas the LAA flow velocity did not differ significantly. Reduced LAA function and swan LAA morphology were independently associated with a higher prevalence of stroke/TIA, whereas the windsock LAA shape proved to be protective. Comparing the differences between the various LAA morphology types, significantly lower LAA volume and LAA orifice area were measured in the windsock LAA shape than in the cauliflower LAA shape.

A novel method of swin transformer with time-frequency characteristics for ECG-based arrhythmia detection

Introduction

Arrhythmia is an important indication of underlying cardiovascular diseases (CVD) and is prevalent worldwide. Accurate diagnosis of arrhythmia is crucial for timely and effective treatment. Electrocardiogram (ECG) plays a key role in the diagnosis of arrhythmia. With the continuous development of deep learning and machine learning processes in the clinical field, ECG processing algorithms have significantly advanced the field with timely and accurate diagnosis of arrhythmia.

Methods

In this study, we combined the wavelet time-frequency maps with the novel Swin Transformer deep learning model for the automatic detection of cardiac arrhythmias. In specific practice, we used the MIT-BIH arrhythmia dataset, and to improve the signal quality, we removed the high-frequency noise, artifacts, electromyographic noise and respiratory motion effects in the ECG signals by the wavelet thresholding method; we used the complex Morlet wavelet for the feature extraction, and plotted wavelet time-frequency maps to visualise the time-frequency information of the ECG; we introduced the Swin Transformer model for classification and achieve high classification accuracy of ECG signals through hierarchical construction and self attention mechanism, and combines windowed multi-head self-attention (W-MSA) and shifted window-based multi-head self-attention (SW-MSA) to comprehensively utilise the local and global information.

Results

To enhance the confidence of the experimental results, we evaluated the performance using intra-patient and inter-patient paradigm analyses, and the model classification accuracies reached 99.34% and 98.37%, respectively, which are better than the currently available detection methods.

Discussion

The results reveal that our proposed method is superior to currently available methods for detecting arrhythmia ECG. This provides a new idea for ECG based arrhythmia diagnosis.

Polygenic risk scores in atrial fibrillation: Associations and clinical utility in disease prediction

Atrial fibrillation (AF) is a common heart arrhythmia and a major cause of cardioembolic stroke. Therefore, accurate prediction is desirable to allow high-risk individuals to be identified early and their risk lowered before complications arise. Polygenic risk scores (PRSs) have become a popular method of quantifying aggregated genetic risk from common variants, but their clinical value in AF remains uncertain. This literature review summarizes the associations between PRS and AF risk and discusses the evidence for the clinical utility of PRS for AF prediction. Stroke risk in patients with AF is also considered. Despite consistent associations between PRS and AF risk, the performance of PRS as a stand-alone tool for AF prediction was poor. However, addition of PRS to the existing AF prediction models commonly improved the predictive performance above that of the clinical models alone, including in cohorts with comorbid cardiovascular disease. Associations between PRS and cardioembolic stroke risk in patients with AF have also been reported, but improvements in stroke prediction models from PRS have been minimal. PRS are likely to add value to the existing clinical AF prediction models; however, standardization of PRS across studies and populations will likely be required before they can be meaningfully adopted into routine clinical practice.

Management of cerebral amyloid angiopathy and atrial fibrillation: We are still far from precision medicine

The use of anticoagulation therapy could prove to be controversial when trying to balance ischemic stroke and intracranial bleeding risks in patients with concurrent cerebral amyloid angiopathy (CAA) and atrial fibrillation (AF). In fact, CAA is an age-related cerebral vasculopathy that predisposes patients to intracerebral hemorrhage. Nevertheless, many AF patients require oral systemic dose-adjusted warfarin, direct oral anticoagulants (such as factor Xa inhibitors) or direct thrombin inhibitors to control often associated with cardioembolic stroke risk. The prevalence of both CAA and AF is expected to rise, due to the aging of the population. This clinical dilemma is becoming increasingly common. In patients with coexisting AF and CAA, the risks/benefits profile of anticoagulant therapy must be assessed for each patient individually due to the lack of a clear-cut consensus with regard to its risks in scientific literature. This review aims to provide an overview of the management of patients with concomitant AF and CAA and proposes the implementation of a risk-based decision-making algorithm.

Proteomic biomarkers for noninvasive left atrial appendage thrombus prediction in patients with atrial fibrillation

INTRODUCTION AND OBJECTIVES

The CHA2DS2-VASc score, used to assess the risk of left atrial appendage thrombus (LAAT) formation in patients with atrial fibrillation (AF), has limited predictive value. Moreover, transesophageal echocardiography imaging, the gold standard diagnostic method to identify thrombi, is semi-invasive. Consequently, there is a need for alternative and noninvasive diagnostic methods for LAAT risk assessment.

METHODS

Deep proteomic analysis was conducted in plasma samples from 8 patients with nonvalvular AF, divided into thrombus and control groups (4 patients in each group) based on the presence or absence of LAAT. Biomarkers associated with LAAT were validated using an enzyme-linked immunosorbent assay in a cohort of 179 patients with available clinical, transthoracic, and transesophageal echocardiography data. Predictive models were developed to assess the improvement in LAAT identification.

RESULTS

The LAAT group had higher CHA2DS2-VASc scores, larger LA diameter, and lower LAA flow velocities. Deep proteomic analysis identified 30 differentially expressed proteins, including myosin light chain 4, prenylcysteine oxidase 1 (PCYOX1), and decorin as potential diagnostic biomarkers of LAAT. The model showed that PCYOX1 and decorin provided an area under the curve (AUC) of 0.970 for LAAT prediction compared with 0.672 in a model including the CHA2DS2-VASc score and LAA cauliflower morphology. The incremental value of proteomic biomarkers for LAAT in patients with nonvalvular AF was further confirmed with the net reclassification improvement and integrated discrimination improvement indices.

CONCLUSIONS

Protein levels of PCYOX1 and decorin improve the predictive performance for LAAT in patients with nonvalvular AF.

Racial and Ethnic Disparities in Initiation of Direct Oral Anticoagulants Among Medicare Beneficiaries

Importance

The influence of race and ethnicity on initiation of direct oral anticoagulants (DOACs) is relatively understudied in Medicare data.

Objective

To investigate disparities in the initiation of DOACs compared with warfarin by race, ethnicity, and social vulnerability.

Design, Setting, and Participants

This retrospective cohort study used a 50% sample of Medicare fee-for-service data from January 1, 2010, to December 31, 2019 (mean patient enrollment duration, 7.7 years). Analysis took place between January 2023 and February 2024. A cohort of older adults (aged ≥65 years) with atrial fibrillation who newly initiated warfarin or DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) was identified.

Exposure

Patients were classified as non-Hispanic White, non-Hispanic Black, and Hispanic.

Main Outcomes and Measures

The likelihood of starting use of DOACs compared with warfarin was modeled, adjusting for race, ethnicity, age, sex, county-level social vulnerability, and other clinical factors.

Results

Among 950 698 anticoagulation initiations, consisting of 680 974 DOAC users and 269 724 warfarin users (mean [SD] age, 78.5 [7.6] years; 52.6% female), 5.2% were Black, 4.3% were Hispanic, and 86.7% were White. During the 10-year study period, DOAC use increased for all demographic groups. After adjustment, compared with White patients, Black patients were 23% less likely (adjusted odds ratio [AOR, 0.77; 95% CI, 0.75-0.79) and Hispanic patients were 13% less likely (AOR, 0.87; 95% CI, 0.85-0.89) to initiate DOAC use. Disparities in DOAC initiation were greatest among Black patients in the earlier years but attenuated during the study period. For instance, in 2010, the OR of Black patients initiating DOACs was 0.54 (95% CI, 0.50-0.57), attenuating linearly over time to 0.69 by 2013 (95% CI, 0.65-0.74) and 0.83 (95% CI, 0.78-0.89) by 2017. By 2019, these differences became nonsignificant (OR, 1.08; 95% CI, 0.99-1.18).

Conclusions and Relevance

In this cohort study of Medicare patients with atrial fibrillation, Black and Hispanic patients were less likely to initiate DOACs for atrial fibrillation, although these differences diminished over time. Identifying the factors behind these early disparities is crucial for ensuring equitable access to novel therapies as they emerge for Black and Hispanic populations.

Adherence to a handheld device-based atrial fibrillation screening protocol is associated with clinical outcomes

OBJECTIVE

To evaluate adherence and adherence consistency to the handheld ECG device-based screening protocol and their association with adverse cerebral and cardiovascular outcomes in two systematic atrial fibrillation (AF) screening programmes.

METHODS

In 2012 (Systematic ECG Screening for Atrial Fibrillation Among 75-Year Old Subjects in the Region of Stockholm and Halland, Sweden (STROKESTOP) study) and 2016 (Stepwise mass screening for atrial fibrillation using N-terminal pro b-type natriuretic peptide (STROKESTOP II) study), half of all 75- and 76-year-old inhabitants of up to two Swedish regions were invited to participate in a systematic AF screening programme. Participants were instructed to perform 30-second measurements twice daily in STROKESTOP and four times daily in STROKESTOP II for 2 weeks. Adherence was defined as the number of measurements performed divided by the number of measurements asked, whereas adherence consistency was defined as the number of days with complete registrations.

RESULTS

In total, 6436 participants (55.7% female) from STROKESTOP and 3712 (59.8% female) from STROKESTOP II were included. Median adherence and adherence consistency were 100 (92-100)% and 12 (11-13) days in STROKESTOP and 90 (75-98)% and 8 (3-11) days in STROKESTOP II. Female sex and lower education were factors associated with both optimal adherence and adherence consistency in both studies. In STROKESTOP, low adherence and adherence consistency were associated with higher risk of adverse cerebral and cardiovascular outcomes (HR for composite primary endpoint 1.30 (1.11 to 1.51), p=0.001), including stroke (HR 1.68 (1.22 to 2.32), p=0.001) and dementia (1.67 (1.27 to 2.19), p<0.001).

CONCLUSIONS

Adherence to twice daily handheld ECG measurements in STROKESTOP was higher than to four times daily measurements in STROKESTOP II. Female sex and lower educational attainment were associated with ≥100% adherence and adherence consistency. Low adherence and adherence consistency were associated with a higher risk of adverse outcomes.

Stroke Related Brain-Heart Crosstalk: Pathophysiology, Clinical Implications, and Underlying Mechanisms

The emergence of acute ischemic stroke (AIS) induced cardiovascular dysfunctions as a bidirectional interaction has gained paramount importance in understanding the intricate relationship between the brain and heart. Post AIS, the ensuing cardiovascular dysfunctions encompass a spectrum of complications, including heart attack, congestive heart failure, systolic or diastolic dysfunction, arrhythmias, electrocardiographic anomalies, hemodynamic instability, cardiac arrest, among others, all of which are correlated with adverse outcomes and mortality. Mounting evidence underscores the intimate crosstalk between the heart and the brain, facilitated by intricate physiological and neurohumoral complex networks. The primary pathophysiological mechanisms contributing to these severe cardiac complications involve the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic and parasympathetic hyperactivity, immune and inflammatory responses, and gut dysbiosis, collectively shaping the stroke-related brain-heart axis. Ongoing research endeavors are concentrated on devising strategies to prevent AIS-induced cardiovascular dysfunctions. Notably, labetalol, nicardipine, and nitroprusside are recommended for hypertension control, while β-blockers are employed to avert chronic remodeling and address arrhythmias. However, despite these therapeutic interventions, therapeutic targets remain elusive, necessitating further investigations into this complex challenge. This review aims to delineate the state-of-the-art pathophysiological mechanisms in AIS through preclinical and clinical research, unraveling their intricate interplay within the brain-heart axis, and offering pragmatic suggestions for managing AIS-induced cardiovascular dysfunctions.

Genetically Predicted Apolipoprotein E Levels with the Risk of Panvascular Diseases: A Mendelian Randomization Study

The aim of this study was to comprehensively assess the causal relationship between the overall genetic effect of circulating ApoE levels and panvascular lesions using newer genome-wide association data and two-sample bidirectional Mendelian randomization (MR) analysis. Two-way MR using single-nucleotide polymorphisms of circulating ApoE as instrumental variables was performed using the highest-priority Genome-wide association study (GWAS) data, with factor-adjusted and data-corrected statistics, to estimate causal associations between circulating ApoE levels and 10 pan-vascular diseases in > 500,000 UK Biobank participants, > 400,000 participants of Finnish ancestry, and numerous participants in a consortium of predominantly European ancestry. Meta-analysis was conducted to assess positive results. After correcting for statistical results, elevated circulating ApoE levels were shown to have a significant protective effect against Cerebral ischemia (CI) [IVW odds ratio (OR) 0.888, 95% Confidence Interval (CI): 0.823-0.958, p = 2.3 × 10-3], Coronary heart disease [IVW OR 0.950,95% CI: 0.924-0.976, p = 2.0 × 10-4] had a significant protective effect and potentially suggestive protective causality against Angina pectoris [IVW odds ratio (OR) 0.961, 95%CI: 0.931-0.991, p = 1.1 × 10-2]. There was a potential causal effect for increased risk of Heart failure (HF) [IVW ratio (OR) 1.040, 95%CI: 1.006-1.060, p = 1.8 × 10-2]. (Bonferroni threshold p < 0.0026, PFDR < 0.05) Reverse MR analysis did not reveal significant evidence of a causal effect of PVD on changes in circulating ApoE levels. Meta-analysis increases reliability of results. Elevated circulating ApoE levels were particularly associated with an increased risk of heart failure. Elevated ApoE levels reduce the risk of cerebral ischemia, coronary heart disease, and angina pectoris, reflecting a protective effect. The possible pathophysiological role of circulating ApoE levels in the development of panvascular disease is emphasized.

Screening for Atrial Fibrillation by Digital Health Technology in Older People in Homecare Settings: A Feasibility Trial

Aims

Users of homecare services are often excluded from clinical trials due to advanced age, multimorbidity, and frailty. Atrial fibrillation (AF) is a common and frequently undiagnosed arrhythmia in the elderly and is associated with severe mortality, morbidity, and healthcare costs. Timely identification prevents associated complications through evidence-based treatment. This study is aimed at assessing the feasibility of AF screening using new digital health technology in older people in a homecare setting.

Methods

Users of homecare services ≥ 65 years old with at least one additional risk factor for stroke in two Norwegian municipalities were assessed for study participation by nurses. Participants performed a continuous prolonged ECG recording using a patch ECG device (ECG247 Smart Heart Sensor).

Results

A total of 144 individuals were assessed for study participation, but only 18 (13%) were included. The main reasons for noninclusion were known AF and/or anticoagulation therapy (25%), severe cognitive impairment (26%), and lack of willingness to participate (36%). The mean age of participants performing the ECG test was 81 (SD ± 7) years, and 9 (50%) were women. All ECG tests were interpretable; the mean ECG monitoring time was 104 hours (IQR 34-338 hours). AF was detected in one individual (6%).

Conclusion

This feasibility study highlights the challenges of enrolling older people receiving homecare services in clinical trials. However, all included participants performed an interpretable and prolonged continuous ECG recording with a digital ECG patch device. This trial is registered with NCT04700865.

Warfarin induced spontaneous gastric intramural haematoma presenting with palpitations

Spontaneous gastric intramural haematoma is an uncommon complication associated with anticoagulant therapy. A patient receiving chronic warfarin for paroxysmal atrial fibrillation was admitted due to atrial fibrillation with rapid ventricular response (RVR). An incidental intra-abdominal mass was detected on a CT scan. Following the initiation of the amiodarone infusion, the patient experienced bleeding attributed to warfarin-amiodarone-induced coagulopathy, with no identifiable bleeding source. Subsequent CT scans revealed an enlargement of the intra-abdominal mass, suggesting gastric intramural haematoma. After coagulopathy reversal, the haematoma is managed conservatively. Our case underscores the potential for incidental bleeding even when the international normalised ratio is within the normal range in patients on chronic warfarin therapy. When managing such patients with atrial fibrillation with RVR, physicians should maintain a high index of suspicion for bleeding, emphasising the importance of prompt coagulopathy reversal.

Evidence of the association between increased use of direct oral anticoagulants and a reduction in the rate of atrial fibrillation-related stroke and major bleeding at the population level (2012-2019)

BACKGROUND

The introduction of direct-acting oral anticoagulants (DOACs) has shown to decrease atrial fibrillation (AF)-related stroke and bleeding rates in clinical studies, but there is no certain evidence about their effects at the population level. Our aim was to assess changes in AF-related stroke and major bleeding rates between 2012 and 2019 in Andalusia (Spain), and the association between DOACs use and events rates at the population level.

METHODS

All patients with an AF diagnosis from 2012 to 2019 were identified using the Andalusian Health Population Base, that provides clinical information on all Andalusian people. Annual ischemic and hemorrhagic stroke, major bleeding rates, and used antithrombotic treatments were determined. Marginal hazard ratios (HR) were calculated for each treatment.

RESULTS

A total of 95,085 patients with an AF diagnosis were identified. Mean age was 76.1±10.2 years (49.7% women). An increase in the use of DOACs was observed throughout the study period in both males and females (p<0.001). The annual rate of ischemic stroke decreased by one third, while that of hemorrhagic stroke and major bleeding decreased 2-3-fold from 2012 to 2019. Marginal HR was lower than 0.50 for DOACs compared to VKA for all ischemic or hemorrhagic events.

CONCLUSIONS

In this contemporary population-based study using clinical and administrative databases in Andalusia, a significant reduction in the incidence of AF-related ischemic and hemorrhagic stroke and major bleeding was observed between 2012 and 2019. The increased use of DOACs seems to be associated with this reduction.

Atrial Fibrillation and Early Vascular Aging: Clinical Implications, Methodology Issues and Open Questions-A Review from the VascAgeNet COST Action

Atrial fibrillation (AF), the most common cardiac arrhythmia, is associated with adverse CV outcomes. Vascular aging (VA), which is defined as the progressive deterioration of arterial function and structure over a lifetime, is an independent predictor of both AF development and CV events. A timing identification and treatment of early VA has therefore the potential to reduce the risk of AF incidence and related CV events. A network of scientists and clinicians from the COST Action VascAgeNet identified five clinically and methodologically relevant questions regarding the relationship between AF and VA and conducted a narrative review of the literature to find potential answers. These are: (1) Are VA biomarkers associated with AF? (2) Does early VA predict AF occurrence better than chronological aging? (3) Is early VA a risk enhancer for the occurrence of CV events in AF patients? (4) Are devices measuring VA suitable to perform subclinical AF detection? (5) Does atrial-fibrillation-related rhythm irregularity have a negative impact on the measurement of vascular age? Results showed that VA is a powerful and independent predictor of AF incidence, however, its role as risk modifier for the occurrence of CV events in patients with AF is debatable. Limited and inconclusive data exist regarding the reliability of VA measurement in the presence of rhythm irregularities associated with AF. To date, no device is equipped with tools capable of detecting AF during VA measurements. This represents a missed opportunity to effectively perform CV prevention in people at high risk. Further advances are needed to fill knowledge gaps in this field.

Identification of Atrial Fibrillation With Single-Lead Mobile ECG During Normal Sinus Rhythm Using Deep Learning

BACKGROUND

The acquisition of single-lead electrocardiogram (ECG) from mobile devices offers a more practical approach to arrhythmia detection. Using artificial intelligence for atrial fibrillation (AF) identification enhances screening efficiency. However, the potential of single-lead ECG for AF identification during normal sinus rhythm (NSR) remains under-explored. This study introduces a method to identify AF using single-lead mobile ECG during NSR.

METHODS

We employed three deep learning models: recurrent neural network (RNN), long short-term memory (LSTM), and residual neural networks (ResNet50). From a dataset comprising 13,509 ECGs from 6,719 patients, 10,287 NSR ECGs from 5,170 patients were selected. Single-lead mobile ECGs underwent noise filtering and segmentation into 10-second intervals. A random under-sampling was applied to reduce bias from data imbalance. The final analysis involved 31,767 ECG segments, including 15,157 labeled as masked AF and 16,610 as Healthy.

RESULTS

ResNet50 outperformed the other models, achieving a recall of 79.3%, precision of 65.8%, F1-score of 71.9%, accuracy of 70.5%, and an area under the receiver operating characteristic curve (AUC) of 0.79 in identifying AF from NSR ECGs. Comparative performance scores for RNN and LSTM were 0.75 and 0.74, respectively. In an external validation set, ResNet50 attained an F1-score of 64.1%, recall of 68.9%, precision of 60.0%, accuracy of 63.4%, and AUC of 0.68.

CONCLUSION

The deep learning model using single-lead mobile ECG during NSR effectively identified AF at risk in future. However, further research is needed to enhance the performance of deep learning models for clinical application.

Initiation patterns of anticoagulants for atrial fibrillation among older UK adults with and without chronic kidney disease, 2010-2020

BACKGROUND

There is a paucity of data on the initiation patterns of anticoagulants among older atrial fibrillation patients with and without chronic kidney disease (CKD).

SETTING AND METHODS

We used the UK Clinical Practice Research Datalink (2010-2020) to conduct a retrospective cohort study to evaluate anticoagulant initiation patterns for older adults (≥65 years) with CKD (N=18 421) and without CKD (N=41 901), categorised by severity of CKD: stages 3a, 3b and 4, and initiation dose by respective direct oral anticoagulant (DOAC).

RESULTS

Over the study period, warfarin initiations sharply declined and were replaced by DOACs regardless of CKD status or stage. By 2020, patients with CKD were modestly more likely (8.8% difference) to initiate apixaban compared with those without CKD (58.8% vs 50.0%; p<0.01). Among patients with CKD, those with stages 3a and 3b CKD had higher apixaban initiations compared with stage 4 CKD (56.9% and 64.6% vs 52.9%, respectively; p<0.01). Conversely, patients with stage 4 CKD were over three times more likely to initiate warfarin (14.7%) compared with those with stage 3a (2.6%) and 3b (4.0%) CKD (p<0.01). Throughout the study period, there was a rise in the proportion of patients initiating the higher 10 mg daily dose for apixaban, with an increase of 20.6% (from 64.3% in 2013 to 84.9% in 2020; p value for trend <0.01) among patients without CKD, and 21.8% (53.1% to 74.9%; p<0.01), 24.4% (18.8% to 43.2%; p<0.01) and 18.5% (0.0% to 18.2%; p<0.01) among patients with stages 3a, 3b and 4 CKD, respectively.

CONCLUSIONS AND RELEVANCE

Initiation of DOACs increased regardless of CKD status and stage, although with a reduced magnitude in severe CKD. Apixaban emerged as the preferred agent, with a secular trend towards the higher initiation dose in all subgroups. These findings illuminate evolving trends and priorities in anticoagulant preferences among patients with and without CKD.

Role of the score for the targeting of atrial fibrillation (STAF) combined with D-dimer in screening ischemic stroke patients with atrial fibrillation

Background

We aim to explore the effect of the score for the targeting of atrial fibrillation (STAF) combined with the serum D-dimer (DD) level in screening acute ischemic stroke patients with atrial fibrillation (AF).

Methods

This study is a retrospective case observation study. This study consecutively selected patients with acute ischemic stroke who were hospitalized in the Department of Neurology at Zhuhai Hospital Affiliated with Jinan University from February 2019 to February 2021. Venous blood was drawn from all patients within 24 hours of hospitalization for DD detection. In accordance with the medical records, the patients were classified into an AF group and a non-AF group and were scored according to the STAF standard. A combined test method was used to estimate the diagnostic screening value of the STAF combined with the DD value for acute ischemic stroke patients with AF.

Standardized 2D atrial mapping and its clinical applications

The visualization and comparison of electrophysiological information in the atrium among different patients could be facilitated by a standardized 2D atrial mapping. However, due to the complexity of the atrial anatomy, unfolding the 3D geometry into a 2D atrial mapping is challenging. In this study, we aim to develop a standardized approach to achieve a 2D atrial mapping that connects the left and right atria, while maintaining fixed positions and sizes of atrial segments across individuals. Atrial segmentation is a prerequisite for the process. Segmentation includes 19 different segments with 12 segments from the left atrium, 5 segments from the right atrium, and two segments for the atrial septum. To ensure consistent and physiologically meaningful segment connections, an automated procedure is applied to open up the atrial surfaces and project the 3D information into 2D. The corresponding 2D atrial mapping can then be utilized to visualize different electrophysiological information of a patient, such as activation time patterns or phase maps. This can in turn provide useful information for guiding catheter ablation. The proposed standardized 2D maps can also be used to compare more easily structural information like fibrosis distribution with rotor presence and location. We show several examples of visualization of different electrophysiological properties for both healthy subjects and patients affected by atrial fibrillation. These examples show that the proposed maps provide an easy way to visualize and interpret intra-subject information and perform inter-subject comparison, which may provide a reference framework for the analysis of the atrial fibrillation substrate before treatment, and during a catheter ablation procedure.

The Impact of Atherosclerotic Burden on Vascular Outcomes in Patients with Stroke and Atrial Fibrillation: The ATHENA study

Introduction: Patients with ischemic stroke (IS) and atrial fibrillation (AF) face a higher risk of recurrent vascular events. This study evaluates the impact of atherosclerotic vascular disease burden across different vascular territories on the risk of vascular events in patients with recent ischemic stroke and AF within 90 days. Patients and Methods: We included patients with IS and AF from the International RAF network in a prospective 90-day follow-up. Atherosclerotic vascular disease was identified by at least one of the following: Symptomatic ischemic heart disease, symptomatic peripheral artery disease, internal carotid stenosis ≥50%, or the presence of plaques in the aorta. The primary outcome was a composite of stroke, transient ischemic attack, systemic embolism, cerebral bleeding, and major extracranial bleeding within 90 days postacute stroke. Patients were categorized into 5 groups based on the number of affected atherosclerotic vascular territories, with those with no atherosclerotic vascular disease as the reference. Kaplan-Meier curves were generated and compared using the log-rank test to determine the predictive value of the number of diseased territories for the risk of events. Data analysis was performed with SPSS/PC Win Package 25.0. Results: Of the 2148 patients (mean age 77.59; 53.86% female), 744 (34.60%) had atherosclerosis. Multivariable analysis revealed that involvement of 3 (hazard ratio [HR] 2.80, 95% confidence interval [CI]: 1.20-6.53) or 4 (HR 6.81, 95% CI: 1.02-36.24) vascular territories was significantly associated with the risk of combined events. Conclusions: In patients with recent ischemic stroke and AF, atherosclerosis across multiple territories correlates with a higher risk of future vascular events.

Metabolic syndrome and ischaemic stroke in non-anticoagulated atrial fibrillation with low CHA2DS2-VASc scores

OBJECTIVE

Conflicting results have been reported on whether metabolic syndrome (MetS) confers an increased risk of ischaemic stroke in atrial fibrillation (AF). We investigated the risk of ischaemic stroke according to MetS in patients with AF who are not indicated for oral anticoagulants.

METHODS

A total of 76 015 oral anticoagulant-naïve patients with AF with low Congestive Heart Failure, Hypertension, Age ≥75 years (Doubled), Diabetes Mellitus, Stroke (Doubled), Vascular Disease, Age 65-74 years, Sex Category (Female) (CHA2DS2-VASc) score (0 and 1) were included from the National Health Information Database. The risk of ischaemic stroke was evaluated according to MetS, the number of MetS components (metabolic burden), and individual metabolic components defined by health examination data within 2 years of AF diagnosis.

RESULTS

MetS was prevalent among 21 570 (28.4%) of the entire study population (mean age 49.8±11.1 years, mean CHA2DS2-VASc score 0.7±0.5). During a mean follow-up of 5.1 years, ischaemic stroke occurred in 1395 (1.84%) patients. MetS was associated with a higher risk of ischaemic stroke (adjusted HR (aHR) 1.19, 95% CI 1.06 to 1.33, p=0.002). Patients with the highest number of MetS components (4 or 5) showed the greatest aHR of 1.38 (95% CI 1.13 to 1.69), whereas those with a single component had a marginal risk of ischaemic stroke (aHR 1.17, 95% CI 0.97 to 1.40). Elevated blood pressure and increased waist circumference were independent components associated with 1.48-fold and 1.15-fold higher risks of ischaemic stroke, respectively.

CONCLUSION

Among AF patients with CHA2DS2-VASc scores of 0 and 1 with no anticoagulation, MetS is associated with an increased risk of ischaemic stroke. Given the linear incremental association between metabolic burden and ischaemic stroke, the integrated management of metabolic derangements in AF is required.

The Prevalence and Determinants of Inappropriate Oral Anticoagulant Use in Patients with Atrial Fibrillation, in Resource-Limited Setting

Introduction

Anticoagulation treatment is routinely underused in patients with atrial fibrillation (AF), particularly in settings with limited resources. The current study is aimed at evaluating the appropriateness of oral anticoagulation treatment among AF patients at the Yekatit 12 Hospital Medical College (Y12HMC), Addis Ababa, Ethiopia.

Methods

Institutional-based retrospective cross-sectional study conducted in Y12HMC from November 2019 to March 2020. During the study period, 256 patients' medical records were found; 231 of them met the eligibility criteria and were included in the study. The data were analyzed using SPSS version 25, descriptive statistics were used to summarize the data, and binary logistic regression was performed to identify predictors of inappropriate anticoagulation management.

Results

The majority of study participants were males (55.8%), and over half of them (57.6%) had a nonvalvular type of AF. The majority of patients (61.9%) were receiving anticoagulant treatment, and of them, warfarin was prescribed to most of the study subjects (71.3%). Nearly half (47.6%) of the study participants had inappropriate anticoagulation treatment; among these, the majority of them (69.1%) were from a valvular type of AF. Patients with a valvular type of AF and having the diagnosis of congestive heart disease as comorbidity showed a statistically significant association towards inappropriate anticoagulation management.

Conclusion

According to the study, a significant portion of AF patients received inappropriate anticoagulant treatment, which may play a significant role for the increased risk of stroke in these groups of patients. All of the inappropriate cases were due to failure to start anticoagulant treatment.

Safety of Direct Oral Anticoagulants for Gastrointestinal Hemorrhage in Patients With Nonvalvular Atrial Fibrillation: A Systematic Review and Meta-analysis of Real-world Studies

GOALS AND BACKGROUND

Since the introduction of Direct Oral Anticoagulants (DOACs), "real-world" studies have investigated their safety profile on gastrointestinal hemorrhage (GIH) when used by patients with Non-Valvular Atrial Fibrillation. We performed a systematic review and meta-analysis to compile and summarize this data after Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

STUDY

Medline and Embase were systematically searched until April 2021. Observational studies that met predefined inclusion criteria were included and hazard ratios (HRs) with 95% CI were extracted. Subgroup analyses based on DOAC doses, history of chronic kidney disease, stroke, prior exposure to VKA (vitamin K antagonist), age, gender, geographic location of population samples, as well as Leave-One-Out and Low/Moderate Risk of Bias sensitivity analyses were performed. A random effects model was used.

RESULTS

A total of 46 studies were included. Apixaban was associated with a reduced risk of GIH compared with Dabigatran (HR: 0.67, 95% CI, 0.56 to 0.81, I2 : 53.28%), Rivaroxaban (HR: 0.56, 95% CI, 0.44 to 0.70, I2 : 79.17%), and VKA (HR: 0.68, 95% CI, 0.60 to 0.78, I2 : 71.93%). Rivaroxaban was associated with increased GIH risk compared with Dabigatran (HR: 1.19, 95% CI, 1.02 to 1.40, I2 : 72.96%) and VKA (HR: 1.16, 95% CI, 1.05 to 1.27, I2 : 81.95%). Dabigatran was associated with similar GIH risk compared with VKA (HR: 1.11, 95% CI, 0.98 to 1.26, I2 : 87.28%).

CONCLUSIONS

Our study shows that Apixaban was associated with a reduction in GIH risk compared with Dabigatran, Rivaroxaban and VKA, whereas Rivaroxaban was associated with an increase in GIH risk compared with both Dabigatran and VKA.

Left Atrial Appendage Occlusion versus Novel Oral Anticoagulation for Stroke Prevention in Atrial Fibrillation-One-Year Survival

Aim To compare the 1-year survival rate of patients with atrial fibrillation (AF) following left atrial appendage occluder (LAAO) implantation vs. treatment with novel oral anticoagulants (NOACs).

METHODS

We have conducted an indirect, retrospective comparison between LAAO and NOAC registries. The LAAO registry is a national prospective cohort of 419 AF patients who underwent percutaneous LAAO between January 2008 and October 2015. The NOACs registry is a multicenter prospective cohort of 3138 AF patients treated with NOACs between November 2015 and August 2018. Baseline patient characteristics were retrospectively collected from coded diagnoses of hospitalization and outpatient clinic notes. Follow-up data was sorted from coded diagnoses and the national civil registry. Subjects were matched according to propensity score. Baseline characteristics were compared using Chi-Square and student's t-test. Survival analysis was performed using Kaplan-Meier survival curves, log-rank test, and multivariable Cox regression, adjusting for possible confounding variables.

RESULTS

This study included 114 subjects who underwent LAAO implantation and 342 subjects treated with NOACs. The mean age of participants was 77.9 ± 7.44 and 77.1 ± 11.2 years in the LAAO and NOAC groups, respectively (p = 0.4). The LAAO group had 70 (61%) men compared to 202 (59%) men in the NOAC group (p = 0.74). No significant differences were found in baseline comorbidities, renal function, or CHA2DS2-VASc score. One-year mortality was observed in 5 (4%) patients and 32 (9%) patients of the LAAO and NOAC groups, respectively. After adjusting for confounders, LAAO was significantly associated with a lower risk for 1-year mortality (HR 0.38, 95%CI 0.14-0.99). In patients with impaired renal function, this difference was even more prominent (HR 0.21 for creatinine clearance (CrCl) < 60 mL/min).

CONCLUSIONS

In a pooled analysis of two registries, we found a significantly lower risk for 1-year mortality in patients with AF who were implanted with LAAO than those treated with NOACs. This finding was more prominent in patients with impaired renal function. Future prospective direct studies should further investigate the efficacy and adverse effects of both treatment strategies.

Accuracy of Artificial Intelligence-Based Technologies for the Diagnosis of Atrial Fibrillation: A Systematic Review and Meta-Analysis

Atrial fibrillation (AF) is the most common arrhythmia with a high burden of morbidity including impaired quality of life and increased risk of thromboembolism. Early detection and management of AF could prevent thromboembolic events. Artificial intelligence (AI)--based methods in healthcare are developing quickly and can be proved as valuable for the detection of atrial fibrillation. In this metanalysis, we aim to review the diagnostic accuracy of AI-based methods for the diagnosis of atrial fibrillation. A predetermined search strategy was applied on four databases, the PubMed on 31 August 2022, the Google Scholar and Cochrane Library on 3 September 2022, and the Embase on 15 October 2022. The identified studies were screened by two independent investigators. Studies assessing the diagnostic accuracy of AI-based devices for the detection of AF in adults against a gold standard were selected. Qualitative and quantitative synthesis to calculate the pooled sensitivity and specificity was performed, and the QUADAS-2 tool was used for the risk of bias and applicability assessment. We screened 14,770 studies, from which 31 were eligible and included. All were diagnostic accuracy studies with case-control or cohort design. The main technologies used were: (a) photoplethysmography (PPG) with pooled sensitivity 95.1% and specificity 96.2%, and (b) single-lead ECG with pooled sensitivity 92.3% and specificity 96.2%. In the PPG group, 0% to 43.2% of the tracings could not be classified using the AI algorithm as AF or not, and in the single-lead ECG group, this figure fluctuated between 0% and 38%. Our analysis showed that AI-based methods for the diagnosis of atrial fibrillation have high sensitivity and specificity for the detection of AF. Further studies should examine whether utilization of these methods could improve clinical outcomes.

Oral Anticoagulant Use in Patients with Atrial Fibrillation at Low Risk of Stroke and Associated Bleeding Complications

BACKGROUND

The use of oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and low stroke risk might cause more harm than benefit. Little attention has been given to address its prevalence and associated consequences. This study aimed to investigate the prescription rate of OACs, identify associated factors, and describe incident bleeding events in low-risk patients.

METHODS

We included patients with a new diagnosis of AF between 1 January 2011 and 31 December 2018 having a low risk of stroke (CHA2DS2-VASc score of 0 for males and 1 for females) from Australian general practice data (MedicineInsight). Patients were classified as OAC users if there was a recorded prescription of an OAC within 60 days of AF diagnosis, and factors associated with the prescription of an OAC were assessed using logistic regression. Recorded incident bleeding events were identified within 6 months after AF diagnosis or after OAC initiation for OAC non-users and users, respectively. The risk of bleeding was compared between the two groups by adjusting their baseline differences using propensity score matching.

RESULTS

The study included 2810 low-risk patients (62.3% male) with a mean age of 49.3 ± 10.8 years. Of the total, 705 (25.1%) patients had a record of OAC prescription within 60 days of diagnosis of AF. Older age (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.03-1.04) and diagnosis periods (2015-2016 [OR 1.46; 95% CI 1.10-1.94] and 2017-2018 [OR 1.65; 95% CI 1.17-2.23] vs. 2011-2012) were associated with higher odds of OAC initiation. Female sex (OR 0.71; 95% CI 0.59-0.85), higher bleeding risk (ORBIT score; OR 0.80; 95% CI 0.68-0.94), and higher socioeconomic index for areas (SEIFA) quintiles (SEIFA quintiles; 2 [OR 0.65; 95% CI 0.48-0.88], 3 [OR 0.74; 95% CI 0.56-0.98], 4 [OR 0.70; 95% CI 0.52-0.94], 5 [OR 0.69; 95% CI 0.52-0.91] compared with quintile 1) were associated with lower odds of OAC prescription. A total of 52 (in 1.8% of patients) incident bleeds were identified, with 18 (2.6%) among OAC users. The rate of bleeding was not significantly different between users and non-users after matching. However, within OAC users, commencement of OAC was associated with an increased risk of bleeding compared to the period before OAC initiation (p = 0.006).

CONCLUSIONS

One in four patients at low risk of stroke received an OAC within 60 days of AF diagnosis. Older age and the period following the widespread availability of direct-acting OACs were associated with an increased likelihood of OAC prescription. Positively, using OACs was not associated with an increased rate of bleeding compared to non-users.

Management and Prognosis of Acute Stroke in Atrial Fibrillation

Atrial fibrillation (AF) is an important risk factor for ischemic stroke (IS). Oral anticoagulation (OAC) significantly reduces the risk of IS in AF but also increases the risk of systemic bleeding, including intracerebral hemorrhage (ICH). AF-related strokes are associated with greater disability and mortality compared to non-AF strokes. The management of patients with AF-related strokes is challenging, and it involves weighing individual risks and benefits in the acute treatment and preventive strategies of these patients. This review summarizes the current knowledge of the acute management of ischemic and hemorrhagic stroke in patients with AF, and the prognosis and potential implications for management both in the acute and long-term setting.

Determinants of Atrial Fibrillation Progression and Its Influence on Overall Mortality in a Cohort of Patients From South India

BACKGROUND

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia associated with increased morbidity and mortality. However, factors influencing AF progression and their impact on all-cause mortality in South Indian patients remain poorly understood.

METHODS

We conducted a retrospective cohort study involving 500 individuals diagnosed with AF. Patient characteristics, including age, sex, and comorbidities, were collected. Left atrial diameter (LAD) and left ventricular ejection fraction (LVEF) were measured via echocardiography. Participants were followed for a median of three years. Cox proportional hazard regression was used to analyze factors associated with AF progression and all-cause mortality.

RESULTS

Of the participants, 60% exhibited persistent or permanent AF, and 40% had paroxysmal AF. The mean age was 63.5 ± 10.8 years, with 60% males and 40% females. Common comorbidities included hypertension (80%), diabetes (50%), and coronary artery disease (35%). The mean LAD was 42.3 ± 5.6 mm and the mean LVEF was 52.7 ± 6.8%; left atrial appendage thrombus (LAAT) was present in 15% of patients. Over the follow-up, 24% experienced all-cause mortality. Multivariate analysis revealed age, hypertension, diabetes, LAD, and LVEF as significant predictors of AF progression (p<0.05). Patients with persistent or permanent AF exhibited a higher risk of progression than those with paroxysmal AF (hazard ratio=1.74, 95% CI, 1.23-2.45). Age, hypertension, heart failure, and AF progression were independent predictors of all-cause mortality (p<0.05).

CONCLUSION

Our study identified age, hypertension, diabetes, LAD, and LVEF as independent predictors of AF progression. Additionally, age, hypertension, heart failure, and AF progression independently predicted all-cause mortality. These findings underscore the need for early detection and management of AF progression and comorbidities to improve outcomes in South Indian AF patients. Prospective studies with larger cohorts are warranted to confirm these findings and explore interventions to prevent AF progression and enhance patient outcomes.

Effect of implantable cardiac monitors on preventing stroke: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND AND AIM

Implantable cardiac monitors (ICM) can facilitate the detection of asymptomatic atrial fibrillation episodes. We performed a systematic review and meta-analysis to investigate whether ICM can prevent stroke in patients with prior stroke and risk factors for stroke.

METHODS

This study included randomized controlled trials comparing ICM with conventional (non-ICM) external cardiac monitoring in patients with prior stroke and risk factors for stroke. We searched Medline, Embase, and CENTRAL from inception until January 5, 2022, without language restriction. Quantitative pooling of the data was undertaken using a random-effects model. The primary outcome was ischemic stroke at the longest follow-up.

RESULTS

Four trials comprising 7237 patients were included. ICM was significantly associated with decreased risk of ischemic stroke (RR 0.76; 95% CI, 0.59-0.97; moderate-quality evidence) in patients with prior stroke and risk factors for stroke. ICM was associated with higher detection of atrial fibrillation (RR 4.21, 95% CI 2.26-7.85) and use of oral anticoagulants (RR 2.29, 95% CI 2.07-2.55).

CONCLUSIONS

ICM results in a significantly lower risk of ischemic stroke than conventional (non-ICM) external cardiac monitoring in patients with prior stroke and risk factors for stroke. Due to the clinical heterogeneity of study population and limited related studies, more trials were needed to furtherly explore the topic in patients with prior stroke or high risk of stroke.

Clinical outcomes of oral anticoagulant discontinuation in atrial fibrillation: a systematic review and meta-analysis

INTRODUCTION

Oral anticoagulants (OACs) should generally be continued lifelong in patients with atrial fibrillation (AF) to ensure optimal benefits, unless contraindications arise. However, discontinuation of OACs might occur for various reasons, potentially affecting clinical outcomes. In this review, we synthesized evidence on the clinical outcomes following OAC discontinuation in patients with AF.

METHODS

We conducted a systematic review and meta-analysis using PubMed, Embase and Scopus. Cohort or case-control studies were included if data were available on clinical outcomes of OAC discontinuation, compared with continuation, in patients with AF. A random-effect meta-analyses were conducted for key outcomes of stroke, mortality, and major bleeding.

RESULTS

Eighteen observational studies having a total of 283,418 patients were included. Discontinuation significantly increased the risk of stroke (hazard ratio [HR] 1.88; 95% confidence interval [CI] 1.58-2.23), all-cause (HR 1.90; 95% CI 1.40-2.59) and cardiovascular (HR 1.83; 95% CI 1.06-3.18) mortality. The risk of major bleeding was not significantly different between the discontinued and continued groups (HR 1.04; 95% CI 0.72-1.52).

CONCLUSIONS

Discontinuation of OAC therapy was associated with an increased risk of stroke and mortality, with no difference in the risk of major bleeding. Acknowledging heterogeneity among the studies, the findings underline the need to ensure continuity of OAC therapy in patients with AF to prevent thrombotic complications and associated mortality.

PROSPERO REGISTRATION NUMBER

CRD42020186116.

Sex-Based Outcomes in Patients Undergoing WATCHMAN Device Implantation

Sex-based disparities in outcomes are reported for various cardiovascular procedures. This study aimed to assess the difference in outcomes in patients who underwent WATCHMAN device implant based on sex. Patients who underwent WATCHMAN device placement, from 2016 to 2018, were identified from the National Inpatient Sample database. The primary outcome was inpatient mortality, and the secondary outcomes were the length of stay (LOS), hospitalization cost (HOC), and periprocedural complications. A logistic regression model was built to perform an adjusted analysis for the outcomes. A total of 12,327 patients underwent WATCHMAN device placement. Female patients were older and more likely to have hypertension (p <0.01) and less likely to have peripheral arterial disease (5.6 vs 7.2, p <0.01), chronic kidney disease (21% vs 26%, p <0.01), and diabetes (18% vs 20%, p = 0.03) and were also at a higher risk for certain periprocedural complications, including pericardiocentesis and anemia requiring blood transfusion (p <0.01 for all). In the unadjusted analysis, the female sex was associated with longer LOS (1.5 vs 1.3 days, p <0.01) and inpatient mortality (0.23 vs 0.10, p = 0.05). The HOC was numerically higher in women but statistically nonsignificant ($120,791 vs $118,554, p = 0.1). In the stepwise, backward, multivariate regression analysis, the female sex  was an independent risk factor for higher LOS (1.5 vs 1.3 days, p <0.01, 95% confidence interval 1.3 to 1.4) after adjusting for potential confounders. The inpatient mortality and HOC were similar between 2 groups after adjusting for potential cofounders in the multivariate regression analysis. Our study suggests that the female sex is an independent risk factor for longer LOS among patients hospitalized for WATCHMAN device placement.

Fully digital self-screening for atrial fibrillation with patch electrocardiogram

AIMS

Atrial fibrillation (AF) is the most common arrhythmia worldwide. The AF is associated with severe mortality, morbidity, and healthcare costs, and guidelines recommend screening people at risk. However, screening methods and organization still need to be clarified. The current study aimed to assess the feasibility of a fully digital self-screening procedure and to assess the prevalence of undetected AF using a continuous patch electrocardiogram (ECG) monitoring system.

METHODS AND RESULTS

Individuals ≥65 years old with at least one additional risk factor for stroke from the general population of Norway were invited to a fully digital continuous self-screening for AF using a patch ECG device (ECG247 Smart Heart Sensor). Participants self-reported clinical characteristics and usability online, and all participants received digital feedback of their results. A total of 2118 individuals with a mean CHA2DS2-VASc risk score of 2.6 (0.9) were enrolled in the study [74% women; mean age 70.1 years (4.2)]. Of these, 1849 (87.3%) participants completed the ECG self-screening test, while 215 (10.2%) did not try to start the test and 54 (2.5%) failed to start the test. The system usability score was 84.5. The mean ECG monitoring time was 153 h (87). Atrial fibrillation was detected in 41 (2.2%) individuals.

CONCLUSION

This fully digitalized self-screening procedure for AF demonstrated excellent feasibility. The number needed to screen was 45 to detect one unrecognized case of AF in subjects at risk for stroke. Randomized studies with long-term follow-up are needed to assess whether self-screening for AF can reduce the incidence of AF-related complications.

CLINICAL TRIALS

NCT04700865.

Predictors of participation in atrial fibrillation screening among community residents in China

BACKGROUND

Atrial fibrillation (AF) is associated with increased stroke risk, but many cases of AF remain undiagnosed. Screening is suggested for early detection of AF. However, nonparticipation in screening is frequently reported, and the underlying causes of why patients choose to participate or not are poorly understood.

OBJECTIVES

To explore factors associated with participation in AF screening in a high-risk population in China.

METHODS

A cross-sectional study was conducted among community residents who were at risk for AF in Guangzhou, China, from February to September 2022. Data on AF knowledge, attitude, subjective norms, perceived behavioral control, and willingness to participate in AF screening were collected. Sociodemographic and clinical data were also collected. Multiple linear stepwise regression analysis was performed to explore predictors for participation in AF screening.

RESULTS

In total, 420 participants were included, with a mean age of 74.4 (±7.43) years old. The results showed that 77.4% of participants reported that they were likely to participate in AF screening. The results of multiple linear regression showed that perceived behavioral control (β =0.591, 95% CI: 0.071, 0.094), attitude (β =0.085, 95% CI: 0.001, 0.025), and having an AF diagnosis (β =0.098, 95% CI: 0.068, 0.494) were positively associated with willingness to participate in AF screening.

CONCLUSIONS

Chinese patients are more likely to participate in AF screening when they perceive great control over their behavior, hold a positive attitude, and have an AF diagnosis. The findings provide clues for future interventions aimed at improving the AF screening participation rate.

P-wave terminal force in lead V1 and atrial fibrillation burden in cryptogenic stroke with implantable loop recorders

Implantable loop recorders (ILRs) are useful for the detection of atrial fibrillation (AF) in patients with cryptogenic stroke (CS). P-wave terminal force in lead V₁ (PTFV₁) is associated with AF detection; however, data on the association between PTFV₁ and AF detection using ILRs in patients with CS are limited. Consecutive patients with CS with implanted ILRs from September 2016 to September 2020 at eight hospitals in Japan were studied. PTFV₁ was calculated by 12-lead ECG before ILRs implantation. An abnormal PTFV₁ was defined as ≥ 4.0 mV × ms. The AF burden was calculated as a proportion based on the duration of AF to the total monitoring period. The outcomes included AF detection and large AF burden, which was defined as ≥ 0.5% of the overall AF burden. Of 321 patients (median age, 71 years; male, 62%), AF was detected in 106 patients (33%) during the median follow-up period of 636 days (interquartile range [IQR], 436-860 days). The median time from ILRs implantation to AF detection was 73 days (IQR, 14-299 days). An abnormal PTFV₁ was independently associated with AF detection (adjusted hazard ratio, 1.71; 95% confidence interval [CI], 1.00-2.90). An abnormal PTFV₁ was also independently associated with a large AF burden (adjusted odds ratio, 4.70; 95% CI, 2.50-8.80). In patients with CS with implanted ILRs, an abnormal PTFV₁ is associated with both AF detection and a large AF burden.Clinical Trial Registration Information: UMIN Clinical Trials Registry 000044366.

Determinants and clinical outcomes of patients who refused anticoagulation: findings from the global GARFIELD-AF registry

OBJECTIVE

There is a substantial incidence of stroke in patients with atrial fibrillation (AF) not receiving anticoagulation. The reasons for not receiving anticoagulation are generally attributed to clinician's choice, however, a proportion of AF patients refuse anticoagulation. The aim of our study was to investigate factors associated with patient refusal of anticoagulation and the clinical outcomes in these patients.

METHODS

Our study population comprised patients in the Global Anticoagulant Registry in the FIELD (GARFIELD-AF) registry with CHA2DS2-VASc≥2. A logistic regression was developed with predictors of patient anticoagulation refusal identified by least absolute shrinkage and selection operator methodology. Patient demographics, medical and cardiovascular history, lifestyle factors, vital signs (body mass index, pulse, systolic and diastolic blood pressure), type of AF and care setting at diagnosis were considered as potential predictors. We also investigated 2-year outcomes of non-haemorrhagic stroke/systemic embolism (SE), major bleeding and all-cause mortality in patients who refused versus patients who received and patients who did not receive anticoagulation for other reasons.

RESULTS

Out of 43 154 AF patients, who were at high risk of stroke, 13 283 (30.8%) did not receive anticoagulation at baseline. The reason for not receiving anticoagulation was unavailable for 38.7% (5146/13 283); of the patients with a known reason for not receiving anticoagulation, 12.5% (1014/8137) refused anticoagulation. Diagnosis in primary care/general practitioner, Asian ethnicity and presence of vascular disease were strongly associated with a higher risk of patient refusal of anticoagulation. Patient refusal of anticoagulation was associated with a higher risk of non-haemorrhagic stroke/SE (adjusted HR (aHR) 1.16 (95% CI 0.77 to 1.76)) but lower all-cause mortality (aHR 0.59 (95% CI 0.43 to 0.80)) compared with patients who received anticoagulation. The GARFIELD-AF mortality score corroborated this result.

CONCLUSION

The data suggest patient refusal of anticoagulation is a missed opportunity to prevent AF-related stroke. Further research is required to understand the patient profile and mortality outcome of patients who refuse anticoagulation.

Subclinical left ventricular systolic dysfunction and incident stroke in the elderly: long-term findings from Cardiovascular Abnormalities and Brain Lesions

AIMS

Heart disease is associated with an increased risk for ischaemic stroke. However, the predictive value of reduced left ventricular ejection fraction (LVEF) for stroke is controversial and only observed in patients with severe reduction. LV global longitudinal strain (LV GLS) can detect subclinical LV systolic impairment when LVEF is normal. We investigated the prognostic role of LV GLS for incident stroke in a predominantly elderly cohort.

METHODS AND RESULTS

Two-dimensional echocardiography with speckle tracking was performed in the Cardiac Abnormalities and Brain Lesions (CABL) study. Among 708 stroke-free participants (mean age 71.4 ± 9.4 years, 60.9% women), abnormal LV GLS (>-14.7%: 95% percentile of the subgroup without risk factors) was detected in 133 (18.8%). During a mean follow-up of 10.8 ± 3.9 years, 47 participants (6.6%) experienced an ischaemic stroke (26 cardioembolic or cryptogenic, 21 other subtypes). The cumulative incidence of ischaemic stroke was significantly higher in participants with abnormal LV GLS than with normal LV GLS (P < 0.001). In multivariate stepwise logistic regression analysis, abnormal LV GLS was associated with ischaemic stroke independently of cardiovascular risk factors including LVEF, LV mass, left atrial volume, subclinical cerebrovascular disease at baseline, and incident atrial fibrillation [hazard ratio (HR): 2.69, 95% confidence interval (CI): 1.47-4.92; P = 0.001]. Abnormal LV GLS independently predicted cardioembolic or cryptogenic stroke (adjusted HR: 3.57, 95% CI: 1.51-8.43; P = 0.004) but not other subtypes.

CONCLUSION

LV GLS was a strong independent predictor of ischaemic stroke in a predominantly elderly stroke-free cohort. Our findings provide insights into the brain-heart interaction and may help improve stroke primary prevention strategies.

Interhospital Variability in Utilization of Cardioversion for Atrial Fibrillation in the Emergency Department

The role for direct current cardioversion (DCCV) in the management of atrial fibrillation (AF) in the emergency department (ED) is unclear. Factors associated with DCCV in current practice are not well described, nor is the variation across patients and institutions. All ED encounters with a primary diagnosis of AF were identified from the Nationwide Emergency Department Sample from 2006 to 2017. The independent association of patient and hospital factors with use of DCCV was assessed using multivariable hierarchical logistic regression. The relative contributions of patient, hospital, and unmeasured hospital factors were assessed using reference effect measures methods. Among 1,280,914 visits to 3,264 EDs with primary diagnosis of AF, 31,422 patients (2.4%) underwent DCCV in the ED. History of stroke (odds ratio [OR] 0.14, 95% confidence interval [CI] 0.09 to 0.22, p <0.001) and dementia (OR 0.14, 95% CI 0.10 to 0.19, p <0.001) was associated with lowest odds of DCCV. Comparing patients more likely to receive DCCV (ninety-fifth percentile) with patients with median risk, the influence of unmeasured hospital factors (OR 14.13, 95% CI 12.55 to 16.09) exceeded the contributions of patient (OR 5.66, 95% CI 5.28 to 6.15) and measured hospital factors (OR 3.89, 95% CI 2.87 to 5.60). In conclusion, DCCV use in the ED varied widely across institutions. Disproportionately large unmeasured hospital variation suggests that presenting hospital is the most determinative factor in the use of DCCV for ED management of AF. Clarification is needed on best practices for management of AF in the ED, including the use of DCCV.

Wrist-worn device combining PPG and ECG can be reliably used for atrial fibrillation detection in an outpatient setting

Aims

The aim was to validate the performance of a monitoring system consisting of a wrist-worn device and a data management cloud service intended to be used by medical professionals in detecting atrial fibrillation (AF).

Methods

Thirty adult patients diagnosed with AF alone or AF with concomitant flutter were recruited. Continuous photoplethysmogram (PPG) and intermittent 30 s Lead I electrocardiogram (ECG) recordings were collected over 48 h. The ECG was measured four times a day at prescheduled times, when notified due to irregular rhythm detected by PPG, and when self-initiated based on symptoms. Three-channel Holter ECG was used as the reference.

Results

The subjects recorded a total of 1,415 h of continuous PPG data and 3.8 h of intermittent ECG data over the study period. The PPG data were analyzed by the system's algorithm in 5-min segments. The segments containing adequate amounts, at least ~30 s, of adequate quality PPG data for rhythm assessment algorithm, were included. After rejecting 46% of the 5-min segments, the remaining data were compared with annotated Holter ECG yielding AF detection sensitivity and specificity of 95.6 and 99.2%, respectively. The ECG analysis algorithm labeled 10% of the 30-s ECG records as inadequate quality and these were excluded from the analysis. The ECG AF detection sensitivity and specificity were 97.7 and 89.8%, respectively. The usability of the system was found to be good by both the study subjects and the participating cardiologists.

Conclusion

The system comprising of a wrist device and a data management service was validated to be suitable for use in patient monitoring and in the detection of AF in an ambulatory setting.Clinical Trial Registration: ClinicalTrials.gov/, NCT05008601.

Prevalence of atrial fibrillation in a regional Victoria setting, findings from the crossroads studies (2001-2003 and 2016-2018)

OBJECTIVE

To estimate the prevalence of atrial fibrillation (AF) in regional Victoria at two time points (2001-2003 and 2016-2018), and to assess the use of electrocardiogram rhythm strips in a rural, community-based study for AF investigation.

DESIGN

Repeated cross-sectional design involving survey of residents of randomly selected households and a clinic. Predictors of AF were assessed using Firth penalised logistic regression, as appropriate for rare events.

SETTING

Goulburn Valley, Victoria.

PARTICIPANTS

Household residents aged ≥16 years. Non-pregnant participants aged 18+ were eligible for the clinic.

MAIN OUTCOME MEASURES

Atrial fibrillation by 12 lead electrocardiogram (earlier study) or electrocardiogram rhythm strip (AliveCor® device) (recent study).

RESULTS

The age standardised prevalence of AF was similar between the two studies (1.6% in the 2001-2003 study and 1.8% in the 2016-2018 study, 95% confidence interval of difference -0.010, 0.014, p = 0.375). The prevalence in participants aged ≥65 years was 3.4% (1.0% new cases) in the recent study. Predictors of AF in the earlier study were male sex, older age and previous stroke, while in the recent study they were previous stroke and self-reported diabetes. AliveCor® traces were successfully classified by the in-built algorithm (91%) vs physician (100%).

CONCLUSION

The prevalence of AF among community-based participants in regional Victoria was similar to predominantly metropolitan-based studies, and was unchanged over time despite increased rates of risk factors. Electrocardiogram rhythm strip investigation was successfully utilised, and particularly benefited from physician overview.

Estimation of mechanical properties by transcatheter monitoring using local impedance and contact force

The mechanical properties of the myocardium in the left ventricle and right atrium were estimated by simultaneously measuring the local impedance (LI) and contact force (CF) using an ablation catheter. Radiofrequency catheter ablation (RFCA) is a well-established arrhythmia treatment. Monitoring the RF power, CF and properties of myocardium during RFCA are necessary to estimate the effect of ablation. Indices, such as CF, lesion size index and ablation index, do not include the myocardium mechanical properties. Therefore, there is the risk of side effects, such as cardiac tamponade, by excessive catheter indentation into vulnerable areas. We propose the simultaneous measurement of LI and CF for estimating the myocardial mechanical properties to reduce the side effects. In this study, an in vitro experimental system was constructed to measure LI and CF via the catheter. The relationship between the porcine myocardial tissue thickness and CF-LI curve was investigated using the left ventricle and right atrium. Power function coefficients approximating the CF-LI curve increased with thicker left ventricle. The thickness of the myocardium can be estimated by simultaneously measuring LI and CF. Intraoperative measurement of the myocardial mechanical properties can be used to determine the ablation conditions at each site.

Imaging and biophysical modelling of thrombogenic mechanisms in atrial fibrillation and stroke

Atrial fibrillation (AF) underlies almost one third of all ischaemic strokes, with the left atrial appendage (LAA) identified as the primary thromboembolic source. Current stroke risk stratification approaches, such as the CHA₂DS₂-VASc score, rely mostly on clinical comorbidities, rather than thrombogenic mechanisms such as blood stasis, hypercoagulability and endothelial dysfunction-known as Virchow's triad. While detection of AF-related thrombi is possible using established cardiac imaging techniques, such as transoesophageal echocardiography, there is a growing need to reliably assess AF-patient thrombogenicity prior to thrombus formation. Over the past decade, cardiac imaging and image-based biophysical modelling have emerged as powerful tools for reproducing the mechanisms of thrombogenesis. Clinical imaging modalities such as cardiac computed tomography, magnetic resonance and echocardiographic techniques can measure blood flow velocities and identify LA fibrosis (an indicator of endothelial dysfunction), but imaging remains limited in its ability to assess blood coagulation dynamics. In-silico cardiac modelling tools-such as computational fluid dynamics for blood flow, reaction-diffusion-convection equations to mimic the coagulation cascade, and surrogate flow metrics associated with endothelial damage-have grown in prevalence and advanced mechanistic understanding of thrombogenesis. However, neither technique alone can fully elucidate thrombogenicity in AF. In future, combining cardiac imaging with in-silico modelling and integrating machine learning approaches for rapid results directly from imaging data will require development under a rigorous framework of verification and clinical validation, but may pave the way towards enhanced personalised stroke risk stratification in the growing population of AF patients. This Review will focus on the significant progress in these fields.

Prevalence of Cardio-Embolic Brain Complications in Permanent and Paroxysmal Atrial Fibrillation Patients

Background: Atrial fibrillation (AF) is the most frequent of all cardiac arrhythmias, with an increasing prevalence in the last 20 years. Cardio-embolic brain complications (CEBC) related to AF often occur or recur, even following appropriate treatment. Method: We conducted a retrospective study and analyzed the presence of stroke, dementia, and Parkinson’s disease (PD) in both paroxysmal and permanent AF patients. The records of 1111 consecutive admitted patients with primary diagnosis of AF at the Municipal Emergency University Hospital, Timisoara, between 2015 and 2016 were examined. Statistical analysis was performed on the patients included in the study based on the inclusion and exclusion criteria. Results: A significant statistical difference was noted among the permanent AF group for stroke (48.75% vs. 26.74%, p < 0.001) and dementia (10.25% vs. 3.86%, p < 0.001) compared to paroxysmal AF patients. Permanent AF patients presented a higher risk of developing stroke, dementia, and PD compared to patients with paroxysmal AF. Meanwhile, male gender and an increase in age showed an increase in the odds of having cardio-embolic brain complications in patients with paroxysmal AF. Conclusion: Based on the results obtained, it can be concluded that the risk of cardio-cerebral embolic complications is greater in permanent AF patients compared to paroxysmal AF cases. Ischemic stroke and dementia are more frequent in the permanent AF group, but analyzing the data regarding the age of onset paroxysmal AF is critical due to the fact that it involves a younger population. Prompt diagnosis and treatment can help significantly in saving stroke patients.

Safety and efficacy of direct oral anticoagulants in geriatric patients with non-valvular atrial fibrillation: A single-center retrospective study

INTRODUCTION

Direct oral anticoagulants (DOACs) are widely employed for antithrombotic prophylaxis in patients with atrial fibrillation (AF). However, there is still uncertainty about their risk-benefit profile in older patients. Here, we evaluated the efficacy, safety, and dose appropriateness of DOACs in a real-world population of outpatients with non-valvular AF, with a specific focus on subjects aged over 80 years and/or with reduced renal function.

MATERIALS AND METHODS

Single-center retrospective study including patients who had been prescribed a DOAC between May 2014 and May 2021 for long-term anticoagulation in non-valvular AF. Patients anticoagulated for <4 weeks were excluded. The primary efficacy outcome was a composite of cardiovascular (CV) death, stroke, or systemic embolism. The primary safety outcome was major bleeding.

RESULTS

A total of 1154 patients (median age 84 yrs., range 57-100 yrs.), among which 862 were 80 years and older, were included. In the subgroup of subjects ≥80 yrs., a subtherapeutic dose of DOAC was associated with an increased incidence of CV mortality, stroke, or systemic embolism (multivariable Cox regression, HR = 2.09, 95 % CI: 1.09-4.02), with no benefit in terms of prevalence of bleeding events (21.5 % vs. 18.6 %, p = 0.428), and the incidence of adverse safety and efficacy outcomes was not increased in patients with a reduced renal function (eGFR ≤30 mL/min). Plasma concentration of DOACs, assessed in a subset of 367 patients, did not increase with advanced age (≥ 80 yrs., two-way ANOVA, p = 0.656) nor with declining eGFR (≤30 mL/min, two-way ANOVA, p = 0.643) and was not associated with adverse safety and efficacy outcomes.

CONCLUSIONS

Data from our study support the use of DOACs in populations of older adults and remark on the risks associated with inappropriate prescriptions in terms of CV mortality and adverse events.

An ECG-based machine learning model for predicting new-onset atrial fibrillation is superior to age and clinical features in identifying patients at high stroke risk

BACKGROUND

Several large trials have employed age or clinical features to select patients for atrial fibrillation (AF) screening to reduce strokes. We hypothesized that a machine learning (ML) model trained to predict AF risk from 12‑lead electrocardiogram (ECG) would be more efficient than criteria based on clinical variables in indicating a population for AF screening to potentially prevent AF-related stroke.

METHODS

We retrospectively included all patients with clinical encounters in Geisinger without a prior history of AF. Incidence of AF within 1 year and AF-related strokes within 3 years of the encounter were identified. AF-related stroke was defined as a stroke where AF was diagnosed at the time of stroke or within a year after the stroke. The efficiency of five methods was evaluated for selecting a cohort for AF screening. The methods were selected from four clinical trials (mSToPS, GUARD-AF, SCREEN-AF and STROKESTOP) and the ECG-based ML model. We simulated patient selection for the five methods between the years 2011 and 2014 and evaluated outcomes for 1 year intervals between 2012 and 2015, resulting in a total of twenty 1-year periods. Patients were considered eligible if they met the criteria before the start of the given 1-year period or within that period. The primary outcomes were numbers needed to screen (NNS) for AF and AF-associated stroke.

RESULTS

The clinical trial models indicated large proportions of the population with a prior ECG for AF screening (up to 31%), coinciding with NNS ranging from 14 to 18 for AF and 249-359 for AF-associated stroke. At comparable sensitivity, the ECG ML model indicated a modest number of patients for screening (14%) and had the highest efficiency in NNS for AF (7.3; up to 60% reduction) and AF-associated stroke (223; up to 38% reduction).

CONCLUSIONS

An ECG-based ML risk prediction model is more efficient than contemporary AF-screening criteria based on age alone or age and clinical features at indicating a population for AF screening to potentially prevent AF-related strokes.

The J-shape Association between Total Bilirubin and Stroke in Older Patients with Obstructive Sleep Apnea Syndrome: A Multicenter Study

OBJECTIVES

To explore the relationship between total bilirubin (TBil) and stroke risk in older patients with obstructive sleep apnea syndrome (OSAS).

METHODS

A total of 1,007 patients with OSAS without stroke history aged ≥ 60 years and with complete serum TBil records were enrolled in this study. The median follow-up was 42 months. Participants were divided into four groups based on the quartile of the baseline serum TBil concentration. Multivariate Cox proportional hazards analysis and restricted cubic spline (RCS) were used to investigate the association of TBil with the incidence of new-onset stroke.

RESULTS

The PRIMARY part: the third quantile TBil level group had the lowest prevalence of stroke among the four groups. The RCS functions depicted a J-type curve relationship between TBil (3.3-33.3 µmol/L) and stroke (nonlinear P < 0.05). When the TBil level was in the range of 3.3 to 11.5 µmol/L, the possible protective influence of bilirubin against stroke in patients with OSAS enhanced with an increasing TBil level. However, when the TBil level exceeded 11.5 µmol/L and gradually increased, the effect of TBil on stroke risk became more and more pronounced. The SECONDARY part: for every 1 µmol/L increase in TBil levels in the range of 11.5 to 33.3 µmol/L, the risk of stroke in patients with OSAS increased by 16.2% (P < 0.001). In addition, there was a higher risk in women with OSAS (hazard ratio (HR)=1.292, 95% confidence interval (95%CI): 1.093-1.528; P = 0.003). Moreover, an increased TBil level alone was significantly associated with stroke in subjects aged < 75 years (HR: 1.190, 95%CI: 1.069-1.324), patients with mild-to-moderate OSAS (HR: 1.215, 95%CI: 1.083-1.364), and individuals without atrial fibrillation (AF) (HR: 1.179, 95%CI: 1.083-1.285) within a TBil level in the range of 11.5 to 33.3 µmol/L.

CONCLUSIONS

Both lower and higher bilirubin levels may increase the risk of stroke in older persons with OSAS, and there was a J-type dose-response relationship. The risk of stroke was lowest when the TBil level was approximately 11.5 µmol/L.

Arrhythmia and other modifiable risk factors in incident dementia and MCI among elderly individuals with low educational levels in Taiwan

Introduction

There is increasing evidence that arrhythmia is a risk factor for dementia; however, it appears that arrhythmia affects the cognitive function of individuals differentially across age groups, races, and educational levels. Demographic differences including educational level have also been found to moderate the effects of modifiable risk factors for cognitive decline.

Methods

This study recruited 1,361 individuals including a group of cognitively unimpaired (CU) individuals, a group of patients with mild cognitive impairment (MCI), and a group of patients with dementia with low education levels. The participants were evaluated in terms of modifiable risk factors for dementia, including arrhythmia and neuropsychiatric symptoms.

Results

Cox proportional hazard regression models revealed that among older MCI patients (>75 years), those with arrhythmia faced an elevated risk of dementia. Among younger MCI patients, those taking anti-hypertensive drugs faced a relatively low risk of dementia. Among younger MCI patients, male sex and higher educational level were associated with an elevated risk of dementia. Among CU individuals, those with coronary heart disease and taking anti-lipid compounds faced an elevated risk of MCI and those with symptoms of depression faced an elevated risk of dementia.

Discussion

The risk and protective factors mentioned above could potentially be used as markers in predicting the onset of dementia in clinical settings, especially for individuals with low educational levels.

Numerical study of the risk of thrombosis in the left atrial appendage of chicken wing shape in atrial fibrillation

Atrial fibrillation (AF) is a common and life-threatening disease. For the patients with AF, more than 90% of the thrombi are formed in the left atrial appendage (LAA), thrombus dislodgement can cause vascular embolism, making them is becoming a high-risk group for stroke. Therefore, identifying the patients with high risk of thrombosis is crucial for advanced stroke warning. To better investigate the mechanism behind thrombus formation in the LAA, this study reconstructed the 3-D Left Atrium (LA) models of six AF volunteer patients by corresponding Computed Tomography (CT) images. Combine the advantages of Computational Fluid Dynamics (CFD), the blood flow field in LA both in AF and sinus heart rate states were studied. The risk of thrombus was evaluated based on the blood viscosity, shear rate thrombus prediction model and Time Average Wall Shear Stress (TAWSS), Oscillatory Shear Index (OSI), and Relative Residence Time (RRT) values. The results showed that the left atrium had lower blood flow velocity and TAWSS values at the LAA in both AF and sinus rhythm, thus the LAA is the most thrombogenic region in the LA. Besides, the RRT value of LAA was generally higher in AF than in sinus rhythm. Therefore, AF carries a higher risk of thrombosis.