Predictive role of atrial fibrillation in cognitive decline: a systematic review and meta-analysis of 2.8 million individuals

Atrial fibrillation and preexisting cognitive impairment in ischemic stroke patients: Dijon Stroke Registry

BACKGROUND

Atrial Fibrillation (AF) is a common cause of ischemic stroke (IS), and is associated with cognitive impairment in the general population. We aimed to compare the prevalence of preexisting cognitive impairment between IS patients with and without AF, and to assess whether prior brain damage could contribute to the observed differences.

METHODS

Patients with acute IS were prospectively identified from the population-based Dijon Stroke Registry, France. Patients who had a CT-scan as brain imaging modality were included in this analysis to assess the presence of preexisting leukoaraiosis, old vascular brain lesions, and cerebral atrophy. Characteristics of patients including prior-to-stroke cognitive status (normal cognition, mild cognitive impairment (MCI), or dementia) were compared between those with and without AF.

RESULTS

Among 916 IS patients, 288 (31.4 %) had AF, of whom 88 had newly diagnosed AF. AF patients had more frequent prior MCI (17.8 % versus 10.2 %) or dementia (22.4 % versus 13.1 %) (p = 0.001), vascular risk factors, and preexisting brain damage. In unadjusted model, preexisting cognitive impairment was associated with AF (OR=2.24; 95 % CI: 1.49-3.37, p < 0.001 for MCI; OR=2.20; 95 % CI: 1.52-3.18, p < 0.001 for dementia). After adjustment for clinical and imaging variables, preexisting mild cognitive impairment (OR=1.87; 95 % CI: 1.06-3.32, p = 0.032) and dementia (OR=1.98; 95 % CI: 1.15-3.40, p = 0.013) were independently associated with AF.

CONCLUSION

AF is a common condition in IS patients and is associated with preexisting cognitive impairment. Brain lesions visible on imaging did not seem to fully account for this association that may involve other mechanisms yet to be elucidated.

Patterns of atrial fibrillation, relevant cardiac structural and functional changes predict functional and cognitive outcomes in patients with ischemic stroke and atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) pattern, relevant cardiac changes are important predictors of outcomes in AF, but their impact on patients with ischemic stroke and AF remained unclear. We aimed to explore the impact of AF patterns, cardiac structural and functional markers on long-term functional and cognitive outcomes in ischemic stroke patients with AF.

METHODS

Ischemic stroke patients diagnosed with AF were enrolled in this retrospective cohort study. AF pattern was defined by both traditional and novel classification, in which patients were divided into AF diagnosed after stroke (AFDAS) and known before stroke (KAF). Left atrial (LA) diameter, left ventricular ejection fraction (LVEF), natriuretic peptide (BNP) and cardiac troponin (cTnI) were dichotomized according to the median value. Outcomes include poor functional outcome and cognitive impairment at the 1-year follow-up. Multivariable logistic regression was performed to validate the association between AF pattern, parameters of cardiac change and functional and cognitive outcome.

RESULTS

A total of 377 patients were included. Non-paroxysmal AF patients had a higher risk of poor functional outcome (OR = 3.59, P < 0.0001) and cognitive impairment (OR = 2.38, P = 0.019) than paroxysmal AF patients, while there were no differences between AFDAS and KAF. Lower LVEF (OR = 1.83, P = 0.045) and higher BNP (OR = 2.66, P = 0.001) were associated with poor functional outcome. Lower LVEF (OR = 2.86, P = 0.004), higher LA diameter (OR = 2.72, P = 0.008) and BNP (OR = 2.31, P = 0.023) were associated with cognitive impairment.

CONCLUSIONS

AF type and related cardiac markers can serve as predictors for poor functional and cognitive outcomes. Comprehensive cardiac assessment and monitoring should be strengthened after stroke.

Mapping the interplay of atrial fibrillation, brain structure, and cognitive dysfunction

INTRODUCTION

Atrial fibrillation (AF) is associated with an elevated risk of cognitive impairment and dementia. Understanding the cognitive sequelae and brain structural changes associated with AF is vital for addressing ensuing health care needs.

METHODS AND RESULTS

We examined 1335 stroke-free individuals with AF and 2683 matched controls using neuropsychological assessments and multimodal neuroimaging. The analysis revealed that individuals with AF exhibited deficits in executive function, processing speed, and reasoning, accompanied by reduced cortical thickness, elevated extracellular free-water content, and widespread white matter abnormalities, indicative of small vessel pathology. Notably, brain structural differences statistically mediated the relationship between AF and cognitive performance.

DISCUSSION

Integrating a comprehensive analysis approach with extensive clinical and magnetic resonance imaging data, our study highlights small vessel pathology as a possible unifying link among AF, cognitive decline, and abnormal brain structure. These insights can inform diagnostic approaches and motivate the ongoing implementation of effective therapeutic strategies. Highlights We investigated neuropsychological and multimodal neuroimaging data of 1335 individuals with atrial fibrillation (AF) and 2683 matched controls. Our analysis revealed AF-associated deficits in cognitive domains of attention, executive function, processing speed, and reasoning. Cognitive deficits in the AF group were accompanied by structural brain alterations including reduced cortical thickness and gray matter volume, alongside increased extracellular free-water content as well as widespread differences of white matter integrity. Structural brain changes statistically mediated the link between AF and cognitive performance, emphasizing the potential of structural imaging markers as a diagnostic tool in AF-related cognitive decline.

Atrial fibrillation, hypertension, and the cerebral vasodilatory reserve

Schematic representation for the cascade model of atrial fibrillation, hypertension, the cerebral vasodilatory reserve, and cognitive decline.

Thromboembolic events and vascular dementia in patients with atrial fibrillation and low apparent stroke risk

The prevention of thromboembolism in atrial fibrillation (AF) is typically restricted to patients with specific risk factors and ignores outcomes such as vascular dementia. This population-based cohort study used electronic healthcare records from 5,199,994 primary care patients (UK; 2005-2020). A total of 290,525 (5.6%) had a diagnosis of AF and were aged 40-75 years, of which 36,340 had no history of stroke, a low perceived risk of stroke based on clinical risk factors and no oral anticoagulant prescription. Matching was performed for age, sex and region to 117,298 controls without AF. During 5 years median follow-up (831,005 person-years), incident stroke occurred in 3.8% with AF versus 1.5% control (adjusted hazard ratio (HR) 2.06, 95% confidence interval (CI) 1.91-2.21; P < 0.001), arterial thromboembolism 0.3% versus 0.1% (HR 2.39, 95% CI 1.83-3.11; P < 0.001), and all-cause mortality 8.9% versus 5.0% (HR 1.44, 95% CI 1.38-1.50; P < 0.001). AF was associated with all-cause dementia (HR 1.17, 95% CI 1.04-1.32; P = 0.010), driven by vascular dementia (HR 1.68, 95% CI 1.33-2.12; P < 0.001) rather than Alzheimer's disease (HR 0.85, 95% CI 0.70-1.03; P = 0.09). Death and thromboembolic outcomes, including vascular dementia, are substantially increased in patients with AF despite a lack of conventional stroke risk factors.

Incidence and progression of atrial fibrillation in patients with and without heart failure using mineralocorticoid receptor antagonists: a meta-analysis

BACKGROUND

Mineralocorticoid receptor antagonists (MRAs) have emerged as potential therapy to target the underlying arrhythmogenic substrate in atrial fibrillation (AF). Nevertheless, there have been inconsistent results on the impact of MRAs on AF.

OBJECTIVE

We sought to evaluate the effect of MRAs on AF incidence and progression in patients with and without heart failure.

METHODS

Electronic databases were searched up to September, 2022 for randomized controlled trials (RCTs) that evaluated MRA use and reported AF outcomes. Primary outcome was a composite of new-onset or recurrent AF. Safety outcomes included hyperkalemia and gynecomastia risks. A random-effects meta-analysis estimated pooled odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

12 RCTs, comprising 11,419 patients treated with various MRAs were included [5960 (52%) on MRA]. On follow-up (6-39 months), 714 (5.5%) patients developed AF. MRA therapy was associated with a 32% reduction in the risk of new-onset or recurrent AF [OR 0.68 (95% CI 0.51-0.92), I2 = 40%]. On subgroup analysis, the greatest benefit magnitude was demonstrated in reducing AF recurrence [OR 0.50 (95% CI 0.30-0.83)] and among patients with left ventricular dysfunction [OR 0.59 (95% CI 0.40-0.85)]. Gynecomastia, but not hyperkalemia, was associated with MRA use. Meta-regression analysis demonstrated that therapy duration was a significant interaction factor driving the effect size (Pinteraction = 0.013).

CONCLUSION

MRA use is associated with a reduction in AF risk, especially AF progression. A prominent effect is seen in patients with heart failure, further augmented by therapy duration. Prospective trials are warranted to evaluate MRA use as upstream therapy for preventing this common arrhythmia.

Atrial Fibrillation and Cognitive Disorders

The prevalence of atrial fibrillation among older adults is increasing. Research has indicated that atrial fibrillation is linked to cognitive impairment disorders such as Alzheimer and vascular dementia, as well as Parkinson disease. Various mechanisms are believed to be shared between atrial fibrillation and cognitive impairment disorders. The specific pathologies and mechanisms of different cognitive disorders are still being studied. Potential mechanisms include cerebral hypoperfusion, ischemic or hemorrhagic infarction, and cerebrovascular reactivity to carbon dioxide. Additionally, circulatory biomarkers and certain infectious organisms appear to be involved. This review offers an examination of the overlapping epidemiology between atrial fibrillation and cognitive disorders, explores different cognitive disorders and their connections with this arrhythmia, and discusses trials and guidelines for preventing and treating atrial fibrillation in patients with cognitive disorders. It synthesizes existing knowledge on the management of atrial fibrillation and identifies areas that require further investigation to bridge the gap in understanding the complex relationship between dementia and atrial fibrillation.

Hypertension and Mild Cognitive Impairment: State-of-the-Art Review

BACKGROUND

Mid-life hypertension is associated with cognitive decline and dementia in later life. Reducing high blood pressure (BP) with antihypertensive agents is a well-researched strategy to prevent dementia and mild cognitive impairment (MCI). However, there is still limited direct evidence to support the approach, and particularly for the treatment of the very old and those with existing MCI.

METHODS

This review presents an overview of the current evidence for the relationship between MCI and hypertension, and of the potential pathophysiological mechanisms related to cognitive decline and incidence dementia in relation to aging.

RESULTS

Although observational data are near consistent in showing an association between mid-life hypertension and MCI and/or dementia, the evidence in relation to hypertension in younger adults and the very old (age >80 years) is much more limited. Most of the commonly available antihypertensive agents appear to provide beneficial effects in reducing the risk dementia, but there is limited evidence to support such treatment in those with existing MCI.

CONCLUSIONS

Further studies are needed to determine the optimal levels of BP control across different age groups, especially in adults with MCI, and which class(es) of antihypertensive agents and duration of treatment best preserve cognitive function in those at risk of, or with established, MCI.

Impact of Helicobacter pylori and metabolic syndrome on mast cell activation-related pathophysiology and neurodegeneration

Both Helicobacter pylori (H. pylori) infection and metabolic syndrome (MetS) are highly prevalent worldwide. The emergence of relevant research suggesting a pathogenic linkage between H. pylori infection and MetS-related cardio-cerebrovascular diseases and neurodegenerative disorders, particularly through mechanisms involving brain pericyte deficiency, hyperhomocysteinemia, hyperfibrinogenemia, elevated lipoprotein-a, galectin-3 overexpression, atrial fibrillation, and gut dysbiosis, has raised stimulating questions regarding their pathophysiology and its translational implications for clinicians. An additional stimulating aspect refers to H. pylori and MetS-related activation of innate immune cells, mast cells (MC), which is an important, often early, event in systemic inflammatory pathologies and related brain disorders. Synoptically, MC degranulation may play a role in the pathogenesis of H. pylori and MetS-related obesity, adipokine effects, dyslipidemia, diabetes mellitus, insulin resistance, arterial hypertension, vascular dysfunction and arterial stiffness, an early indicator of atherosclerosis associated with cardio-cerebrovascular and neurodegenerative disorders. Meningeal MC can be activated by triggers including stress and toxins resulting in vascular changes and neurodegeneration. Likewise, H.pylori and MetS-related MC activation is linked with: (a) vasculitis and thromboembolic events that increase the risk of cardio-cerebrovascular and neurodegenerative disorders, and (b) gut dysbiosis-associated neurodegeneration, whereas modulation of gut microbiota and MC activation may promote neuroprotection. This narrative review investigates the intricate relationship between H. pylori infection, MetS, MC activation, and their collective impact on pathophysiological processes linked to neurodegeneration. Through a comprehensive search of current literature, we elucidate the mechanisms through which H. pylori and MetS contribute to MC activation, subsequently triggering cascades of inflammatory responses. This highlights the role of MC as key mediators in the pathogenesis of cardio-cerebrovascular and neurodegenerative disorders, emphasizing their involvement in neuroinflammation, vascular dysfunction and, ultimately, neuronal damage. Although further research is warranted, we provide a novel perspective on the pathophysiology and management of brain disorders by exploring potential therapeutic strategies targeting H. pylori eradication, MetS management, and modulation of MC to mitigate neurodegeneration risk while promoting neuroprotection.

The Role of Helicobacter pylori and Metabolic Syndrome-Related Mast Cell Activation Pathologies and Their Potential Impact on Pregnancy and Neonatal Outcomes

Helicobacter pylori infection, a significant global burden beyond the gastrointestinal tract, has long been implicated in various systemic pathologies. Rising evidence suggests that the bacterium's intricate relationship with the immune system and its potential to induce chronic inflammation impact diverse pathophysiological processes in pregnant women that may in turn affect the incidence of several adverse pregnancy and neonate outcomes. Helicobacter pylori infection, which has been linked to metabolic syndrome and other disorders by provoking pericyte dysfunction, hyperhomocysteinemia, galectin-3, atrial fibrillation, gut dysbiosis, and mast cell activation pathologies, may also contribute to adverse pregnancy and neonatal outcomes. Together with increasing our biological understanding of the individual and collective involvement of Helicobacter pylori infection-related metabolic syndrome and concurrent activation of mast cells in maternal, fetus, and neonatal health outcomes, the present narrative review may foster related research endeavors to offer novel therapeutic approaches and informed clinical practice interventions to mitigate relevant risks of this critical topic among pregnant women and their offspring.

Atrial fibrillation increases the risk of all-cause dementia, Alzheimer's disease, and vascular dementia: A cohort study of 373, 415 participants in the UK Biobank

BACKGROUND

Accumulated evidence has highlighted the association between atrial fibrillation and the risk of developing dementia.

METHODS

This current cohort study utilized data from the UK Biobank to explore the association between atrial fibrillation (AF) and all-cause dementia (ACD), encompassing its main subtypes (Alzheimer's disease (AD), and vascular dementia (VD)). Cox proportional hazards models were applied to examine the association of AF and dementia with its primary subtypes after adjusting for different sets of covariates. Hazard ratios (HRs) with 95 % confidential intervals (CIs) were estimated to quantify the associated risks. Competing risk model was applied in sensitivity analysis.

RESULTS

After exclusion, 373, 415 participants entered the primary analysis. Among these, 27, 934 (7.48 %) were with a history AF at baseline, while 345, 481 (92.52 %) were without. During a mean follow-up of 13.45 years, ACD was diagnosed in 1215 individuals with AF and 3988 individuals without AF. Participants with AF had higher risks of ACD (1.79 [1.67-1.91]), AD (1.48 [1.32-1.65]), and VD (2.46 [2.17-2.80]) in the fully adjusted Cox regression models. Results of subgroup and sensitivity analyses predominantly aligned with the positive associations in primary analysis.

LIMITATIONS

The applicability of our findings to diverse ethnicities might require careful consideration and the behind biological mechanisms need to be further revealed.

CONCLUSIONS

It indicated that people with atrial fibrillation had an increased future risk of all-cause dementia, Alzheimer's disease, vascular dementia. Atrial fibrillation screening and prevention strategies should take into account to prevent and delay the onset of dementia.

Connections between Cognitive Impairment and Atrial Fibrillation in Patients with Diabetes Mellitus Type 2

(1) Background: Cognitive decline (CD), considered a precursory state of dementia, is frequently encountered in patients with diabetes mellitus type 2 (DM-2) and might even have a higher prevalence in those with associated atrial fibrillation (AF). In this study, we aimed to research if the association of DM-2 and AF favors a precocious onset of CD. (2) Methods: This study was conducted on 160 patients, featuring 50 with DM-2, 54 with DM-2 and AF, and 56 subjects without DM-2 and AF, all evaluated clinically and with five neuropsychiatric scales. (3) Results: The Mini-Mental-State-Examination (MMSE), Montreal Cognitive Assessment (MoCA), Activities of Daily Living Score (ADL), Instrumental Activities of Daily Living Score (IADL), and Geriatric Depression Scale (GDS-15) were significantly altered in patients with DM-2 and AF in comparison to patients without these diseases. The logistic regression model indicated that, in patients with DM-2 and AF, an increase of one year in age is associated with a 7.3% augmentation of the risk of a precocious onset of CD (MMSE < 27). (4) Conclusions: CD is more frequent in patients with DM-2, especially when associated with AF, versus those without DM-2 and AF. Our findings suggest that an older age and associated dyslipidemia represent risk factors for CD in patients with DM-2.

Bibliometric Insights Into the Evolution of Atrial Fibrillation and Dementia Research 2002-2022

BACKGROUND In response to the escalating prevalence of atrial fibrillation (AF) and its potential correlation with cognitive impairment and dementia, we conducted a comprehensive bibliometric analysis to assess current research trends, contributors, and collaborative networks in this evolving interdisciplinary field. MATERIAL AND METHODS Articles published between 2002 and 2022 were extracted from the Web of Science database and carefully screened, yielding 328 publications. Two reviewers independently conducted the screening and quality appraisal. We employed sophisticated tools such as CiteSpace, VOSviewer, and Bibliometrix (R-Studio's R tool) to succinctly summarize and thoroughly analyze the publications. RESULTS A total of 328 publications, comprising 262 papers and 66 reviews, were included in the final analysis. The number of publications exhibited a consistent year-on-year increase, demonstrating an average annual growth rate of 20.57%. These publications originated from 41 countries and regions, with the highest contributions observed from the United States, United Kingdom, Italy, and China. Notably, the University of Liverpool emerged as the most prolific institution, while the most prolific author was Lip GYH from the United Kingdom. The journal with the most publications is the journal of the American Heart Association (19 articles). The most popular keywords in order were: risk and stroke (n=101), dementia (n=100), decline (n=70), prevalence (n=67), and Alzheimer's disease. CONCLUSIONS This study shows the current research status and emerging trends in atrial fibrillation's link to dementia and cognitive impairment. It highlights global growth and collaboration patterns while offering a comprehensive view of their interrelationship, pointing toward future research directions.

Umbrella review and Delphi study on modifiable factors for dementia risk reduction

A 2013 systematic review and Delphi consensus study identified 12 modifiable risk and protective factors for dementia, which were subsequently merged into the "LIfestyle for BRAin health" (LIBRA) score. We systematically evaluated whether LIBRA requires revision based on new evidence. To identify modifiable risk and protective factors suitable for dementia risk reduction, we combined an umbrella review of systematic reviews and meta-analyses with a two-round Delphi consensus study. The review of 608 unique primary studies and opinions of 18 experts prioritized six modifiable factors: hearing impairment, social contact, sleep, life course inequalities, atrial fibrillation, and psychological stress. Based on expert ranking, hearing impairment, social contact, and sleep were considered the most suitable candidates for inclusion in updated dementia risk scores. As such, the current study shows that dementia risk scores need systematic updates based on emerging evidence. Future studies will validate the updated LIBRA score in different cohorts. HIGHLIGHTS: An umbrella review was combined with opinions of 18 dementia experts. Various candidate targets for dementia risk reduction were identified. Experts prioritized hearing impairment, social contact, and sleep. Re-assessment of dementia risk scores is encouraged. Future work should evaluate the predictive validity of updated risk scores.

Atrial Fibrillation and Dementia: Focus on Shared Pathophysiological Mechanisms and Therapeutic Implications

OBJECTIVES

Atrial fibrillation (AF) and dementia are highly prevalent chronic and debilitating conditions, especially affecting the older population. This review focuses on possible common pathophysiological mechanisms that could explain the association between the 2 conditions.

DESIGN

Narrative review.

SETTING AND PARTICIPANTS

Evidence from epidemiologic, observational, and interventional studies evaluating prevalence and incidence of cognitive impairment in patients with AF.

METHODS

Broad literature search between December 2022 and May 2023. Eligible categories for inclusion comprised interventional studies, observational studies, systematic reviews, and meta-analysis.

RESULTS

Evidence from different cohorts has shown that AF increases the risk of dementia, although the association with dementia subtypes is not always unequivocal. According to recent evidence, common pathophysiological mechanisms include thromboembolism and hypercoagulable states, proinflammatory state, infection, cerebral hypoperfusion, and brain atrophy. Moreover, we reviewed the evidence on therapeutic measures to prevent dementia in patients with AF.

CONCLUSIONS AND IMPLICATIONS

Screening for cognition in patients with AF is of paramount importance, given the shared risk factors and common pathophysiological mechanisms. More evidence is needed to clarify whether antiarrhythmic and anticoagulant therapy have an impact on cognitive outcomes in AF patients.

Association of Atrial Fibrillation with Remote Intracerebral Hemorrhage After Intravenous Thrombolysis: Results from a Multicenter Study in China

INTRODUCTION

This study aimed to investigate the association between atrial fibrillation (AF), particularly newly diagnosed AF, and remote intracerebral hemorrhage (rICH) in patients with ischemic stroke who were treated with intravenous thrombolysis (IVT).

METHODS

This observational study was conducted on patients with ischemic stroke who received IVT with recombinant tissue-type plasminogen activator. The data were taken from a multicenter prospective registry of a Chinese population. rICH was defined as any extraischemic hemorrhage detected on computerized tomography (CT) 24 h after intravenous thrombolysis. We collected and compared the demographic data and clinical characteristics of all the patients with rICH to those of patients without any type of hemorrhagic transformation. The association between AF and rICH was analyzed using univariate analysis and binary logistic regression.

RESULTS

A total of 20,697 patients were included in the study, with 1566 (7.6%) experiencing intracerebral hemorrhage (ICH), 586 (2.8%) experiencing rICH, and 19,131 (92.4%) not experiencing any form of hemorrhagic transformation. Univariate analysis revealed significant differences in age, pre-thrombolysis systolic blood pressure, baseline National Institute of Health Stroke Scale score, previously known AF, newly diagnosed AF, coronary heart disease, congestive heart failure, hyperhomocysteinemia, and history of thrombolysis between the rICH and control groups (P < 0.05). Further multivariate logistic regression analysis indicated that total AF (OR 1.821, 95% CI 1.082-3.065, P < 0.05), previously known AF (OR 1.470, 95% CI 1.170-1.847), and newly diagnosed AF (OR 1.920, 95% CI 1.304-2.825) were independently associated with rICH.

CONCLUSIONS

This study suggests that AF, regardless of whether it is newly diagnosed or previously known, may be associated with the occurrence of rICH following intravenous thrombolysis. Interestingly, our findings suggest that newly diagnosed AF may have a stronger impact on rICH than previously known AF, although confirmation from more studies is needed.

Atrial Fibrillation Health Literacy Questionnaire (AFHLQ): The development of an AF-specific health literacy questionnaire

Background

Health literacy is a key enabler of effective behavioural modification in chronic diseases. While patient reported outcome measures (PROMs) exists for patient with atrial fibrillation (AF), none address risk factors comprehensively. The aim of the study was to develop and qualitatively validate a disease specific PROM that incorporates knowledge on risk factors and assesses interactive and critical health literacy of people living with AF.

Methods

The 47-item Atrial Fibrillation Health Literacy Questionnaire (AFHLQ) was developed and validated through a qualitative research design. Expert and Consumer focus groups, each consisting of seven participants provided opinion.

Results

The 47-item questionnaire consists of 5 domains: (1) what is AF, (2) what are the symptoms of AF, (3) why do people get AF, (4) management of AF, and (5) what measures can slow or prevent the progression of AF. Recommendations resulted in several changes to the original 47 item list during the qualitative validation process: 13 original items were removed, and 13 new items were added. The response categories were also simplified from a Likert scale to "yes", "no" or "don't know".

Conclusion

A 47-item AFHLQ instrument was developed and validated with modifications made through clinical expert and consumer opinion. This tool has a potential to be used to evaluate and guide interventions at a clinical and population level to understand and improve AF health literacy and outcomes.

Effects of rhythm-control and rate-control strategies on cognitive function and dementia in atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

Growing evidence suggests that atrial fibrillation (AF) is an independent risk factor for cognitive impairment and dementia, even in the absence of thromboembolic events and stroke. Whether rhythm-control therapy can protect cognitive function remains unclear. We aimed to evaluate the efficacy of rhythm-control strategies in patients with AF regarding cognitive function and dementia risk.

METHODS

We systematically searched the PubMed, Embase and Cochrane Library databases for randomised clinical trials, cohort and case-control studies evaluating the associations between rhythm-control strategies and cognitive function outcomes up to May 2023. We assessed the risk of bias using the ROBINS-I and the Cochrane risk-of-bias tool. Both fixed- and random-effects models were used to create summary estimates of risk.

RESULTS

We included a total of 14 studies involving 193,830 AF patients. In the pooled analysis, compared with rate-control, rhythm-control therapy was significantly associated with a lower risk of future dementia (hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.62-0.89; I2 = 62%). Among the rhythm-control strategies, AF ablation is a promising treatment that was related to significantly lower risks of overall dementia (HR 0.62; 95% CI 0.56-0.68; I2 = 42%), Alzheimer's disease (HR 0.78; 95% CI 0.66-0.92; I2 = 0%) and vascular dementia (HR 0.58; 95% CI 0.42-0.80; I2 = 31%). Pooled results also showed that compared with patients without ablation, those who underwent AF ablation had significantly greater improvement in cognitive score (standardized mean difference (SMD) 0.85; 95% CI 0.30-1.40; P = 0.005; I2 = 76%).

CONCLUSIONS

Rhythm-control strategies, especially ablation, are effective in protecting cognitive function, reducing dementia risk and thus improving quality of life in AF patients.

Heart-brain interaction in cardiogenic dementia: pathophysiology and therapeutic potential

Diagnosis and treatment of patients with cardiovascular and neurologic diseases primarily focus on the heart and brain, respectively. An increasing number of preclinical and clinical studies have confirmed a causal relationship between heart and brain diseases. Cardiogenic dementia is a cognitive impairment caused by heart dysfunction and has received increasing research attention. The prevention and treatment of cardiogenic dementia are essential to improve the quality of life, particularly in the elderly and aging population. This study describes the changes in cognitive function associated with coronary artery disease, myocardial infarction, heart failure, atrial fibrillation and heart valve disease. An updated understanding of the two known pathogenic mechanisms of cardiogenic dementia is presented and discussed. One is a cascade of events caused by cerebral hypoperfusion due to long-term reduction of cardiac output after heart disease, and the other is cognitive impairment regardless of the changes in cerebral blood flow after cardiac injury. Furthermore, potential medications for the prevention and treatment of cardiogenic dementia are reviewed, with particular attention to multicomponent herbal medicines.

Evaluation of the Relationship between Cognitive Impairment and Atria Score Systems in Patients with Atrial Fibrillation

Background

Atrial fibrillation (AF) is the main arrhythmia associated with thromboembolic complications and cognitive impairment. In this study, we aimed to evaluate the relationship between cognitive impairment and different scoring systems developed for AF to improve the medical follow-up of cognitive impairment.

Methods

Between January 2019 and December 2020, 124 patients between the age of 30 and 80 years, diagnosed with AF for at least 5 years and complaining about memory impairment during cardiological follow-up, were included in the study. The patients were divided into two groups based on their cognitive status as assessed by the Mini-Mental State Examination group 1 consisted of 52 patients with cognitive impairment and group 2 comprised 72 patients without cognitive impairment.

Results

The ATRIA bleeding score had a positive moderate correlation (r = 0.454, P < 0.001), the ATRIA stroke score had a strong correlation (r = 0.738, P < 0.001), and the SAMe-TT2R2 score had a strong correlation (r = 0.688, P < 0.001) with cognitive impairment. However, CHADS2 and CHA2DS2VASc scores were not statistically correlated with cognitive impairment. According to the receiver operating characteristic (ROC) curve, the area under the curve (AUC) of the ATRIA bleeding score was 0.761 with a 95% confidence interval (CI) of 0.678-0.844 and P < 0.001; also, for the ATRIA stroke score, AUC was 0.930 with a 95% CI of 0.886-0.974 and P < 0.001. In addition, for the SAMe-TT2R2 score, AUC was 0.895 with a 95% CI of 0.838-0.952 and P < 0.001. In the pairwise comparison of AUC on ROC curves, the ATRIA stroke score and the SAMe-TT2R2 score were statistically similar (P = 0.324). ATRIA bleeding, ATRIA stroke, and SAMe-TT2R2 scores were greater than CHADS2 stroke score (P: 0.0004, P < 0.0001, and P < 0.0001, respectively), but CHA2DS2-VASc and CHADS2 stroke scores were statistically similar (P: 0.402).

Conclusion

Both ATRIA stroke and SAMe-TT2R2 scoring systems can provide a better correlation than CHADS2 and CHA2DS2-VASc scores in patients with AF to evaluate their cognitive status. These two scores can be more useful to monitor the patients with AF for medical follow-up of cognitive status.

Detection of brain lesions after catheter ablation depends on imaging criteria: insights from AXAFA-AFNET 5 trial

AIMS

Left atrial catheter ablation is well established in patients with symptomatic atrial fibrillation (AF) but associated with risk of embolism to the brain. The present analysis aims to assess the impact of diffusion-weighted imaging (DWI) slice thickness on the rate of magnetic resonance imaging (MRI)-detected ischaemic brain lesions after ablation.

METHODS AND RESULTS

AXAFA-AFNET 5 trial (NCT02227550) participants underwent MRI using high-resolution (hr) DWI (slice thickness: 2.5-3 mm) and standard DWI (slice thickness: 5-6 mm) within 3-48 h after ablation. In 321 patients with analysable brain MRI (mean age 64 years, 33% female, median CHA2DS2-VASc 2), hrDWI detected at least one acute brain lesion in 84 (26.2%) patients and standard DWI in 60 (18.7%; P < 0.01) patients. High-resolution diffusion-weighted imaging detected more lesions compared to standard DWI (165 vs. 104; P < 0.01). The degree of agreement for lesion confirmation using hrDWI vs. standard DWI was substantial (κ = 0769). Comparing the proportion of DWI-detected lesions, lesion distribution, and total lesion volume per patient, there was no difference in the cohort of participants undergoing MRI at 1.5 T (n = 52) vs. 3 T (n = 269).

CONCLUSION

The pre-specified AXAFA-AFNET 5 sub-analysis revealed significantly increased rates of MRI-detected acute brain lesions using hrDWI instead of standard DWI in AF patients undergoing ablation. In comparison to DWI slice thickness, MRI field strength had a no significant impact in the trial. Comparing the varying rates of ablation-related MRI-detected brain lesions across previous studies has to consider these technical parameters. Future studies should use hrDWI, as feasibility was demonstrated in the multicentre AXAFA-AFNET 5 trial.

Influence of exercise training on the left atrium: implications for atrial fibrillation, heart failure, and stroke

The left atrium (LA) plays a critical role in receiving pulmonary venous return and modulating left ventricular (LV) filling. With the onset of exercise, LA function contributes to the augmentation in stroke volume. Due to the growing focus on atrial imaging, there is now evidence that structural remodeling and dysfunction of the LA is associated with adverse outcomes including incident cardiovascular disease. In patients with established disease, pathological changes in atrial structure and function are associated with exercise intolerance, increased hospital admissions and mortality, independent of left ventricular function. Exercise training is widely recommended in patients with cardiovascular disease to improve patient outcomes and maintain functional capacity. There are widely documented changes in LV function with exercise, yet less attention has been given to the LA. In this review, we first describe LA physiology at rest and during exercise, before exploring its association with cardiac disease outcomes including atrial fibrillation, heart failure, and stroke. The adaptation of the LA to short- and longer-term exercise training is evaluated through review of longitudinal studies of exercise training in healthy participants free of cardiovascular disease and athletes. We then consider the changes in LA structure and function among patients with established disease, where adverse atrial remodeling may be implicated in the disease process. Finally, we consider important future directions for assessment of atrial structure and function using novel imaging modalities, in response to acute and chronic exercise.

Genetic Evidence for Causal Association Between Atrial Fibrillation and Dementia: A Mendelian Randomization Study

Background The knowledge gap regarding whether the correlation between atrial fibrillation (AF) and dementia in observational studies is causation or driven by other shared risk factors remains substantially unfilled. Methods and Results We performed a comprehensive 2-sample Mendelian randomization study to evaluate the causal effect of AF on overall dementia and its subtypes, including vascular dementia, Alzheimer dementia, Lewy body dementia, and frontotemporal dementia. The primary results in inverse variance-weighted analyses were further validated by various Mendelian randomization sensitivity analyses. Additionally, we conducted multivariable Mendelian randomization to examine 10 candidate mediators of the causal association of AF and dementia. Genetic predisposition to AF was modestly associated with an increased risk of overall dementia (odds ratio, 1.140 [95% CI, 1.023-1.271]; P=0.018) and strongly associated with vascular dementia (odds ratio, 1.350 [95% CI, 1.076-1.695]; P=0.010). Genetically predicted AF indicated neutral effects on Alzheimer dementia, Lewy body dementia, and frontotemporal dementia. In multivariable Mendelian randomization analysis, the total effect of AF on overall dementia was remarkably attenuated by adjusting for genetic effect for ischemic stroke (odds ratio, 1.068 [95% CI, 0.953-1.197]; P=0.259) and low cardiac output (odds ratio, 1.046 [95% CI, 0.926-1.181]; P=0.475), indicating that the causal association of genetically predicted AF with dementia was potentially mediated by ischemic stroke and low cardiac output. The causal effect of genetically predicted AF on dementia was independent of cerebral small-vessel disease and brain volume phenotypes. Conclusions Our findings provided novel evidence supporting the causal effect of genetically predicted AF on dementia mediated by ischemic stroke and low cardiac output. Future clinical trials are warranted to evaluate the potential role of appropriate AF management in dementia prevention.

Mid-term changes in cognitive functions in patients with atrial fibrillation: a longitudinal analysis of the Swiss-AF cohort

Background

Longitudinal association studies of atrial fibrillation (AF) and cognitive functions have shown an unclear role of AF-type and often differ in methodological aspects. We therefore aim to investigate longitudinal changes in cognitive functions in association with AF-type (non-paroxysmal vs. paroxysmal) and comorbidities in the Swiss-AF cohort.

Methods

Seven cognitive measures were administered up to five times between 2014 and 2022. Age-education standardized scores were calculated and association between longitudinal change in scores and baseline AF-type investigated using linear mixed-effects models. Associations between AF-type and time to cognitive drop, an observed score of at least one standard deviation below individual's age-education standardized cognitive scores at baseline, were studied using Cox proportional hazard models of each cognitive test, censoring patients at their last measurement. Models were adjusted for baseline covariates.

Results

2,415 AF patients (mean age 73.2 years; 1,080 paroxysmal, 1,335 non-paroxysmal AF) participated in this Swiss multicenter prospective cohort study. Mean cognitive scores increased longitudinally (median follow-up 3.97 years). Non-paroxysmal AF patients showed smaller longitudinal increases in Digit Symbol Substitution Test (DSST), Cognitive Construct Score (CoCo)and Trail Making Test part B (TMT-B) scores vs. paroxysmal AF patients. Diabetes, history of stroke/TIA and depression were associated with worse performance on all cognitive tests. No differences in time to cognitive drop were observed between AF-types in any cognitive test.

Conclusion

This study indicated preserved cognitive functioning in AF patients, best explained by practice effects. Smaller practice effects were found in non-paroxysmal AF patients in the DSST, TMT-B and the CoCo and could indicate a marker of subtle cognitive decline. As diabetes, history of stroke/TIA and depression-but not AF-type-were associated with cognitive drop, more attention should be given to risk factors and underlying mechanisms of AF.

Silent cerebral lesions following catheter ablation for atrial fibrillation: a state-of-the-art review

Atrial fibrillation is associated with neurocognitive comorbidities such as stroke and dementia. Evidence suggests that rhythm control-especially if implemented early-may reduce the risk of cognitive decline. Catheter ablation is highly efficacious for restoring sinus rhythm in the setting of atrial fibrillation; however, ablation within the left atrium has been shown to result in MRI-detected silent cerebral lesions. In this state-of-the-art review article, we discuss the balance of risk between left atrial ablation and rhythm control. We highlight suggestions to lower the risk, as well as the evidence behind newer forms of ablation such as very high power short duration radiofrequency ablation and pulsed field ablation.

Ablation of atrial fibrillation and dementia risk reduction during long-term follow-up: a nationwide population-based study

AIMS

This study investigated the epidemiological characteristics of new-onset dementia in patients with atrial fibrillation (AF) and the association of catheter ablation with different subtypes of dementia.

METHODS AND RESULTS

We conducted a population-based, retrospective cohort study using data from the Taiwan National Health Insurance Research Database. In total, 136 774 patients without a history of dementia were selected after 1:1 propensity score matching based on age (with AF vs. without AF). A competing risk model was used to investigate the three subtypes of dementia: Alzheimer's disease, vascular dementia, and other/mixed dementia. Inverse probability of treatment weighting (IPTW) was performed to minimize the impact on dementia risk due to the imbalanced baseline characteristics. After a median follow-up period of 6.6 years, 8704 events of new-onset dementia occurred. Among all AF patients developing dementia, 73% were classified as having Alzheimer's disease, 16% as having vascular dementia, and 11% as having other/mixed dementia. The cumulative incidence of dementia in AF patients was higher than those without AF (log-rank test: P < 0.001 for both before and after IPTW). In patients with AF undergoing catheter ablation, the total dementia risk decreased significantly [P = 0.015, hazard ratio (HR): 0.74, 95% confidence interval (CI): 0.58-0.94] after multivariable adjustment, but not for the subtype of vascular dementia (P = 0.59, HR: 0.86, 95% CI: 0.49-1.50).

CONCLUSION

Patients with AF have a higher incidence of all types of dementia, including Alzheimer's disease, vascular dementia, and a mixed type of dementia. Alzheimer's disease is less likely to occur in patients with AF undergoing catheter ablation.

Comparing the risk of dementia in subjects with atrial fibrillation using non-vitamin K antagonist oral anticoagulants versus vitamin K antagonists: a Belgian nationwide cohort study

BACKGROUND

Atrial fibrillation (AF) is associated with cognitive decline, with anticoagulated subjects potentially having a reduced risk compared with non-anticoagulated subjects. However, whether non-vitamin K antagonist oral anticoagulants (NOACs) may reduce the risk of dementia compared with vitamin K antagonists (VKAs) is unclear yet. Therefore, the risk of dementia was compared between AF subjects on NOACs versus VKAs.

METHODS

AF subjects initiating anticoagulation between 2013 and 2019 were identified in Belgian nationwide data. Inverse probability of treatment weighted Cox regression was used to investigate cognitive outcomes.

RESULTS

Among 237,012 AF subjects (310,850 person-years (PYs)), NOAC use was associated with a significantly lower risk of dementia (adjusted hazard ratio (aHR) 0.91, 95% confidence interval (CI) (0.85-0.98)) compared with VKAs. A trend towards a lower risk of vascular dementia (aHR 0.89, 95% CI (0.76-1.04)) and significantly lower risk of other/unspecified dementia (aHR 0.91, 95% CI (0.84-0.99)) were observed with NOACs compared with VKAs, whereas the risk of Alzheimer's disease was similar (aHR 0.99, 95% CI (0.88-1.11)). Apixaban (aHR 0.91, 95% CI (0.83-0.99)) and edoxaban (aHR 0.79, 95% CI (0.63-0.99)) were associated with significantly lower risks of dementia compared with VKAs, while risks were not significantly different with dabigatran (aHR 1.02, 95% CI (0.93-1.12)) and rivaroxaban (aHR 0.97, 95% CI (0.90-1.05)). Comparable risks of dementia were observed between individual NOACs, except for significantly lower risks of dementia (aHR 0.93, 95% CI (0.87-0.98)) and other/unspecified dementia (aHR 0.90 (0.84-0.97)) with apixaban compared with rivaroxaban.

CONCLUSION

NOACs were associated with a significantly lower risk of dementia compared with VKAs, likely driven by apixaban and edoxaban use.

Prevalence, risk factors, and clinical outcomes of remote intracerebral hemorrhage after intravenous thrombolysis in acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND

Hemorrhagic transformation (HT) is a common complication of alteplase treatment. However, the prevalence rate, risk factors, and clinical outcomes of remote intracerebral hemorrhage (rICH) after intravenous thrombolysis in acute ischemic stroke are not well understood.

METHODS

Following a previously registered protocol, the PubMed, Web of Science, and Embase databases were systematically searched to identify relevant literature up to June 2022. Cohort studies reporting thrombolysis-related rICH in patients with acute ischemic stroke were included. Random effects models were used to calculate pooled prevalence rate, mean difference (MD) or odds ratio (OR) with corresponding 95% confidence interval (CI).

RESULTS

Fourteen studies with 52,610 patients were included in this meta-analysis. The pooled rICH prevalence was 3.2% (95% CI 3.1-3.4%). Compared to patients without intracerebral hemorrhage (ICH), those with rICH were older, more likely to be female, and had a higher proportion of prior stroke, chronic heart failure and cardioembolism, and higher diastolic blood pressure. Small vessel disease markers (e.g., white matter hyperintensities and cerebral microbleeds) were strongly associated with rICH. The presence of rICH decreased the likelihood of favorable outcomes (OR 0.36, 95% CI 0.31-0.41) and increased the risk of mortality (OR 4.37, 95% CI 2.86-6.67).

CONCLUSIONS

Although rICH is uncommon after intravenous thrombolysis, its presence can lead to worse functional outcomes and higher mortality in acute ischemic stroke. Patients at high risk of rICH must be identified based on potential risk factors.

Mechanisms and Clinical Manifestations of Cognitive Decline in Atrial Fibrillation Patients: Potential Implications for Preventing Dementia

Atrial fibrillation (AF) patients face an approximate 1.5-fold increased risk of cognitive decline compared with the general population. Among poststroke AF patients, the risk of cognitive decline is even higher with an estimated threefold increase. This article provides a narrative review on the current evidence and highlights gaps in knowledge and areas for future research. Although earlier studies hypothesized that the association between AF and cognitive decline is mainly a consequence of previous ischemic strokes, more recent evidence also suggests such an association in AF patients without a history of clinical stroke. Because AF and cognitive decline mainly occur among elderly individuals, it is not surprising that both entities share multiple risk factors. In addition to clinically overt ischemic strokes, silent brain infarcts and other brain injury are likely mechanisms for the increased risk of cognitive decline among AF patients. Oral anticoagulation for stroke prevention in AF patients with additional stroke risk factors is one of the only proven therapies to prevent brain injury. Whether a broader use of oral anticoagulation, or more intense anticoagulation in some patients are beneficial in this context needs to be addressed in future studies. Although direct studies are lacking, it is reasonable to recommend optimal treatment of comorbidities and risk factors for the prevention of cognitive decline and dementia.

Impact of atrial fibrillation on the cognitive decline in Alzheimer's disease

BACKGROUND

Atrial fibrillation (AF) is a strong risk factor for Alzheimer's disease (AD) independent of ischemic stroke. However, the clinicopathological impact of AF on the severity of AD has not been well elucidated. We aimed to investigate the clinical differences between dementia patients with AF and those without AF by means of imaging data.

METHODS

Following approval from the institutional ethics committee, patients with newly diagnosed AD or amnestic mild cognitive impairment (aMCI) were retrospectively screened (n = 170, 79.5 ± 7.4 years old). Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Based on the MRI data, the cerebral volume, cerebral microbleeds (CMBs), periventricular white matter lesions (WMLs), and deep WMLs were evaluated. The regional cerebral blood flow (rCBF) was measured using ¹²³I-IMP SPECT.

RESULTS

Of the patients, 14 (8.2%) and 156 (91.8%) had AF (AF group) and sinus rhythm (SR group), respectively. The AF group had significantly lower MMSE scores than the SR group (average [standard deviation (SD)]: 19.4 [4.4] and 22.0 [4.4], respectively; p = 0.0347). Cerebral volume and CMBs did not differ between the two groups. The periventricular WMLs, but not the deep WMLs, were significantly larger in the AF group than in the SR group (mean [SD] mL: 6.85 [3.78] and 4.37 [3.21], respectively; p = 0.0070). However, there was no significant difference in rCBF in the areas related to AD pathology between the two groups.

CONCLUSION

AD and aMCI patients with AF showed worse cognitive decline along with larger periventricular WMLs compared to those with SR, although the reduction of rCBF was not different between patients with AF and SR. The white matter lesions may be a more important pathology than the impairment of cerebral blood flow in dementia patients with AF. A larger study is needed to confirm our findings in the future.

Comparative risk of dementia among patients with atrial fibrillation treated with catheter ablation versus anti-arrhythmic drugs

Atrial fibrillation (AF) is associated with an increased risk of dementia. Emerging evidence suggests AF suppression is associated with reduced risk of dementia, but the optimal strategy to achieve this is unknown. We sought to compare the risk of dementia in patients with AF who underwent catheter ablation (CA) versus anti-arrhythmic drug (AAD) treatment. METHODS AND RESULTS: Using the 2000 to 2021 Optum Clinformatics database, patients with AF who underwent CA versus AAD treatment (≥1 prescription fill for ≥2 different AADs) were identified and propensity score matched overall and within sex subgroups. A cause-specific hazard model was performed to assess dementia overall and in sex-specific subgroups. After matching, there were 19,088 patients per group. CA was associated with a 41% lower risk of dementia compared with AAD alone (1.9% vs 3.3%; hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.52-0.67, log-rank P < .0001). When examined by sex, dementia risk reduction associated with CA versus AAD use alone was observed among both males (HR 0.55, 95% CI 0.46-0.66) and females (HR 0.60, 95% CI 0.50-0.72). Though not studied as a primary outcome, patients treated with CA were also observed to have 49% lower associated risk of mortality compared with AAD only (HR 0.51 95% CI 0.46-0.55, P < .0001). CONCLUSIONS: Among patients treated for AF, CA was associated with significantly lower risk of dementia and death compared with AADs only. These reductions in risk associated with CA versus AAD were seen in both males and females.

Atrial Fibrillation and the Risk of Early‐Onset Dementia: A Systematic Review and Meta‐Analysis

Background

Recent studies have identified an increased risk of dementia in patients with atrial fibrillation (AF). However, both AF and dementia usually manifest late in life. Few studies have investigated this association in adults with early‐onset dementia. The aim of this study was to investigate the relationship between AF and early‐onset dementia.

Methods and Results

We searched the PubMed/MEDLINE, Embase, and Scopus databases through April 15, 2022, for studies reporting on the association between AF and dementia in adults aged <70 years, without language restrictions. Two reviewers independently performed the study selection, assessed the risk of bias, and extracted the study data. We performed a meta‐analysis of early‐onset dementia risk according to occurrence of AF using a random‐effects model. We retrieved and screened 1006 potentially eligible studies. We examined the full text of 33 studies and selected the 6 studies that met our inclusion criteria. The pooled analysis of their results showed an increased risk of developing dementia in individuals with AF, with a summary relative risk of 1.50 (95% CI, 1.00–2.26) in patients aged <70 years, and 1.06 (95% CI, 0.55–2.06) in those aged <65 years.

Conclusions

In this systematic review and meta‐analysis, AF was a risk factor for dementia in adults aged <70 years, with an indication of a slight and statistically imprecise excess risk already at ages <65 years. Further research is needed to assess which characteristics of the arrhythmia and which mechanisms play a role in this relationship.