Atrial fibrillation is associated with lower cognitive performance in the Framingham offspring men

Type 2 diabetes and late-onset Alzheimer's disease and related dementia: A longitudinal cohort study integrating polygenic risk score

BackgroundThe inherent genetic effects were not established between type 2 diabetes (T2DM) and Alzheimer's disease and related dementia (ADRD).ObjectiveWe aimed to investigate the association between T2DM and ADRD by integrating T2DM polygenic risk score (PRS) and applying matching in every subgroup.MethodsWe utilized UK Biobank First-occurrences datasets. T2DM were 1:1 matched to non-T2DM using propensity scores generated by 8 covariates; age at diagnosis, sex, cerebrovascular disease, ischemic heart disease, hypertensive disorders, lipid disorders, obesity, and mood disorders. T2DM PRS was additionally matched in T2DM PRS matched analysis. Subgroup analyses by age at diagnosis, sex, and APOE4 genotype were performed with the same matching criteria within each subgroup. Cox proportional hazard and Fine & Gray competing risk model were utilized.ResultsIn T2DM PRS unmatched cohort, 24,583 T2DM were 1:1 matched to non-T2DM. The mean age at diagnosis was around 62 years old, with females constituting around 40%. Up to 25-year follow-up, ADRD rate/1000 person-years was 0.88 versus 1.52 (Non-T2DM versus T2DM); PRS unmatched (cHR: 1.72, 95% CI: 1.46-2.03) and matched (cHR:1.75, 95% CI: 1.47-2.09). Except for older age onset (≥75 years), the other subgroups demonstrated significantly increased ADRD risks in T2DM. T2DM PRS was higher in non-ADRD group across all subgroups. Contrarily, T2DM PRS was higher in ADRD in younger onset group (<55 years).ConclusionsT2DM is one of the strong risk factors of ADRD but genetic T2DM effect does not contribute to ADRD risk. However, a genetic link might be present in younger age onset group.

The role of atrial fibrillation in vascular cognitive impairment and dementia: epidemiology, pathophysiology, and preventive strategies

The aging population in Europe faces a substantial burden from dementia, with vascular cognitive impairment and dementia (VCID) being a preventable cause. Atrial fibrillation (AF), a common cardiac arrhythmia, increases the risk of VCID through mechanisms such as thromboembolism, cerebral hypoperfusion, and inflammation. This review explores the epidemiology, pathophysiology, and preventive strategies for AF-related VCID. Epidemiological data indicate that AF prevalence rises with age, affecting up to 12% of individuals over 80. Neuroimaging studies reveal chronic brain changes in AF patients, including strokes, lacunar strokes, white matter hyperintensities (WMHs), and cerebral microbleeds (CMHs), while cognitive assessments show impairments in memory, executive function, and attention. The COVID-19 pandemic has exacerbated the underdiagnosis of AF, leading to an increase in undiagnosed strokes and cognitive impairment. Many elderly individuals did not seek medical care due to fear of exposure, resulting in delayed diagnoses. Additionally, reduced family supervision during the pandemic contributed to missed opportunities for early detection of AF and related complications. Emerging evidence suggests that long COVID may also elevate the risk of AF, further complicating the management of this condition. This review underscores the importance of early detection and comprehensive management of AF to mitigate cognitive decline. Preventive measures, including public awareness campaigns, patient education, and the use of smart devices for early detection, are crucial. Anticoagulation therapy, rate and rhythm control, and addressing comorbid conditions are essential therapeutic strategies. Recognizing and addressing the cardiovascular and cognitive impacts of AF, especially in the context of the COVID-19 pandemic, is essential for advancing public health.

Association of Atrial Fibrillation and Cognitive Dysfunction: A Comprehensive Narrative Review of Current Understanding and Recent Updates

Atrial fibrillation (AF) is the most common sustained arrhythmia in adults. The prevalence of both AF and dementia is steadily rising and is expected to rise further in the coming decades. There is increasing evidence to suggest an association between AF and various degrees of cognitive dysfunction, from mild cognitive impairment to severe dementia. In this review, we aimed to discuss the epidemiological aspects, pathophysiological mechanisms, role of neuroimaging, impact of treatment modalities, and clinical and socioeconomic impact of this association. Numerous observational studies and meta-analyses have revealed this association to exist in AF patients with and without a history of stroke, and the association also persists after adjusting for shared risk factors such as hypertension and diabetes mellitus. Various pathophysiological mechanisms have been proposed for this association, including silent cerebral infarcts, cerebral microbleeds, cerebral hypoperfusion, inflammation, and atherosclerosis. While neuroimaging findings have been utilized to suggest some of these pathophysiological mechanisms, more studies are needed to further elucidate this and to determine the potential role of neuroimaging in altering anticoagulation and other treatment decisions. Anticoagulants have shown effectiveness in reducing the rate of cognitive decline in AF patients; however, their role in low-risk AF patients remains under investigation. Even though AF patients receiving catheter ablation may have post-operative cognitive dysfunction in the short term, long-term follow-up studies have shown an improvement in cognitive function following ablation. Cognitive decline in AF patients often occurs with greater functional decline and other psychosocial impairments such as depression and anxiety and future research on this association must incorporate aspects of social determinants of health and associated outcomes.

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.

Cognitive Impairment in Heart Failure: A Heart Failure Society of America Scientific Statement

Cognitive impairment is common among adults with heart failure (HF), as both diseases are strongly related to advancing age and multimorbidity (including both cardiovascular and noncardiovascular conditions). Moreover, HF itself can contribute to alterations in the brain. Cognition is critical for a myriad of self-care activities that are necessary to manage HF, and it also has a major impact on prognosis; consequently, cognitive impairment has important implications for self-care, medication management, function and independence, and life expectancy. Attuned clinicians caring for patients with HF can identify clinical clues present at medical encounters that suggest cognitive impairment. When present, screening tests such as the Mini-Cog, and consideration of referral for comprehensive neurocognitive testing may be indicated. Management of cognitive impairment should focus on treatment of underlying causes of and contributors to cognitive impairment, medication management/optimization, and accommodation of deficiencies in self-care. Given its implications on care, it is important to integrate cognitive impairment into clinical decision making. Although gaps in knowledge and challenges to implementation exist, this scientific statement is intended to guide clinicians in caring for and meeting the needs of an increasingly complex and growing subpopulation of patients with HF.

Is catheter ablation associated with preservation of cognitive function? An analysis from the SAGE-AF observational cohort study

OBJECTIVES

To examine the associations between catheter ablation treatment (CA) vs. medical management and cognitive impairment among older adults with atrial fibrillation (AF).

METHODS

Ambulatory patients who had AF, were ≥65-years-old, and were eligible to receive oral anticoagulation could be enrolled into the SAGE (Systematic Assessment of Geriatric Elements)-AF study from internal medicine and cardiology clinics in Massachusetts and Georgia between 2016 and 2018. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) tool at baseline, 1-, and 2 years. Cognitive impairment was defined as a MoCA score ≤ 23. Multivariate-adjusted logistic regression of longitudinal repeated measures was used to examine associations between treatment with CA vs. medical management and cognitive impairment.

RESULTS

887 participants were included in this analysis. On average, participants were 75.2 ± 6.7 years old, 48.6% women, and 87.4% white non-Hispanic. 193 (21.8%) participants received a CA before enrollment. Participants who had previously undergone CA were significantly less likely to be cognitively impaired during the 2-year study period (aOR 0.70, 95% CI 0.50-0.97) than those medically managed (i.e., rate and/or rhythm control), even after adjusting with propensity score for CA. At the 2-year follow-up a significantly greater number of individuals in the non-CA group were cognitively impaired (MoCA ≤ 23) compared to the CA-group (311 [44.8%] vs. 58 [30.1%], p = 0.0002).

CONCLUSION

In this 2-year longitudinal prospective cohort study participants who underwent CA for AF before enrollment were less likely to have cognitive impairment than those who had not undergone CA.

Is Catheter Ablation Associated with Preservation of Cognitive Function? An Analysis From the SAGE-AF Observational Cohort Study

OBJECTIVES

To examine the associations between catheter ablation treatment (CA) versus medical management and cognitive impairment among older adults with atrial fibrillation (AF).

METHODS

Ambulatory patients who had AF, were ≥ 65-years-old, and were eligible to receive oral anticoagulation could be enrolled into the SAGE (Systematic Assessment of Geriatric Elements)-AF study from internal medicine and cardiology clinics in Massachusetts and Georgia between 2016 and 2018. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) tool at baseline, one-, and two years. Cognitive impairment was defined as a MoCA score ≤ 23. Multivariate-adjusted logistic regression of longitudinal repeated measures was used to examine associations between treatment with CA vs. medical management and cognitive impairment.

RESULTS

887 participants were included in this analysis. On average, participants were 75.2 ± 6.7 years old, 48.6% women, and 87.4% white non-Hispanic. 193 (21.8%) participants received a CA before enrollment. Participants who had previously undergone CA were significantly less likely to be cognitively impaired during the two-year study period (aOR 0.70, 95% CI 0.50-0.97) than those medically managed (i.e., rate and/or rhythm control), even after adjusting with propensity score for CA. At the two-year follow-up a significantly greater number of individuals in the non-CA group were cognitively impaired (MoCA ≤ 23) compared to the CA-group (311 [44.8%] vs. 58 [30.1%], p=0.0002).

CONCLUSIONS

In this two-year longitudinal prospective cohort study participants who underwent CA for AF before enrollment were less likely to have cognitive impairment than those who had not undergone CA.

Racial/Ethnic Disparities in the Alzheimer's Disease Link with Cardio and Cerebrovascular Diseases, Based on Hawaii Medicare Data

Background

There is an expanding body of literature implicating heart disease and stroke as risk factors for Alzheimer's disease (AD). Hawaii is one of the six majority-minority states in the United States and has significant racial health disparities. The Native-Hawaiians/Pacific-Islander (NHPI) population is well-known as a high-risk group for a variety of disease conditions.

Objective

We explored the association of cardiovascular disease with AD development based on the Hawaii Medicare data, focusing on racial disparities.

Methods

We utilized nine years of Hawaii Medicare data to identify subjects who developed heart failure (HF), ischemic heart disease (IHD), atrial fibrillation (AF), acute myocardial infarction (AMI), stroke, and progressed to AD, using multistate models. Propensity score-matched controls without cardiovascular disease were identified to compare the risk of AD after heart disease and stroke. Racial/Ethnic differences in progression to AD were evaluated, accounting for other risk factors.

Results

We found increased risks of AD for AF, HF, IHD, and stroke. Socioeconomic (SE) status was found to be critical to AD risk. Among the low SE group, increased AD risks were found in NHPIs compared to Asians for all conditions selected and compared to whites for HF, IHD, and stroke. Interestingly, these observations were found reversed in the higher SE group, showing reduced AD risks for NHPIs compared to whites for AF, HF, and IHD, and to Asians for HF and IHD.

Conclusions

NHPIs with poor SE status seems to be mostly disadvantaged by the heart/stroke and AD association compared to corresponding whites and Asians.

Is the association between cognitive disease progression and atrial fibrillation modified by sex?

INTRODUCTION

It is unclear if sex differences exist in cognitive disease progression in mild cognitive impairment (MCI) and dementia associated with atrial fibrillation (AF).

METHODS

Using a variety of statistical methods, we examined sex differences between AF and neuropsychological tests and cognitive disease progression, using the National Alzheimer's Coordinating Center data (N = 43,630).

RESULTS

AF is associated with higher odds of dementia (odds ratio [OR] 3.00, 95% confidence interval [CI] [1.22, 7.37] in women and MCI in women (OR 3.43, 95% CI [1.55, 7.55]) versus men. Women with AF and normal baseline cognition had a higher risk of disease progression (hazard ratio [HR] 1.26, 95% CI [1.06, 1.50]) from normal to MCI and from MCI to vascular dementia (HR3.27, 95% CI [1.89, 5.65]) than men with AF or men and women without AF.

DISCUSSION

AF was associated with more rapid progression to MCI and dementia in women, but more research is needed to confirm these findings.

The Impact of Atrial Fibrillation Treatment Strategies on Cognitive Function

There is increasing evidence to suggest that atrial fibrillation is associated with a heightened risk of dementia. The mechanism of interaction is unclear. Atrial fibrillation-induced cerebral infarcts, hypoperfusion, systemic inflammation, and anticoagulant therapy-induced cerebral microbleeds, have been proposed to explain the link between these conditions. An understanding of the pathogenesis of atrial fibrillation-associated cognitive decline may enable the development of treatment strategies targeted towards the prevention of dementia in atrial fibrillation patients. The aim of this review is to explore the impact that existing atrial fibrillation treatment strategies may have on cognition and the putative mechanisms linking the two conditions. This review examines how components of the 'Atrial Fibrillation Better Care pathway' (stroke risk reduction, rhythm control, rate control, and risk factor management) may influence the trajectory of atrial fibrillation-associated cognitive decline. The requirements for further prospective studies to understand the mechanistic link between atrial fibrillation and dementia and to develop treatment strategies targeted towards the prevention of atrial fibrillation-associated cognitive decline, are highlighted.

Association Between Atrial Fibrillation and Domain-Specific Cognitive Decline - Insights From the Systolic Blood Pressure Intervention Trial

BACKGROUND

There is a dearth of evidence to characterize longitudinal changes in domain-specific cognitive function related to atrial fibrillation (AF).

METHODS AND RESULTS

This study enrolled 2,844 participants from the Systolic Blood Pressure Intervention Trial (SPRINT). Cognitive function was assessed at baseline and biennially during the follow-up period. Declines in global function and 4 major cognitive domains (i.e., memory, processing speed, language, and executive function) were fitted and compared between participants with and without AF using robust linear mixed-effect models. There were 252 participants with prevalent AF (mean [±SD] age 72.0±8.5 years; 30% women) and 2,592 participants without AF (mean age 67.9±8.4 years; 38% women). The annual decline in global function scores was greater among participants with than without AF (-0.016 vs. -0.012 points); however, the difference was not statistically significant (P=0.33). Processing speed declined faster in participants with prevalent AF, with a distinct difference of -0.013 points/year (95% CI -0.024~-0.001 points/year; P=0.02). For the memory, executive function, and language domains, there were no significant differences in the rate of cognitive decline between participants with and without AF.

CONCLUSIONS

In this post hoc analysis of the SPRINT trial, processing speed was the most prominent cognitive domain affected by AF, which may be beneficial for the early screening of cognitive dysfunction.

Neurocognitive function in patients with atrial fibrillation undergoing pulmonary vein isolation

Background

Atrial fibrillation (AF) is associated with cognitive dysfunction. However, neurocognitive function in AF patients undergoing pulmonary vein isolation (PVI) has not been well studied. The aim of this analysis is to compare neurocognitive function in patients who did or did not undergo PVI.

Materials and methods

We used data from the Swiss Atrial Fibrillation Cohort study (Swiss-AF), a prospective, observational, multicenter study in Switzerland. Patients with documented AF were enrolled and data of 1,576 patients without history of PVI and with complete information on PVI status and neurocognitive function were used. Information on PVI was collected at baseline and during 1 year of follow-up. Neurocognitive testing was performed at baseline and after 1 year of follow-up, using the Montreal Cognitive Assessment (MoCA), trail making test (TMT) A and B, digit symbol substitution test (DSST) and semantic fluency test (SFT). To investigate the association of PVI with neurocognitive function, we use propensity score matching (1:3) and inverse probability of treatment weighting (IPTW).

Results

The mean age of this population was 74 ± 8 years, 27.1% were women. Overall, 88 (5.5%) patients underwent PVI during 1 year of follow-up. Using ITPW (n = 1576), PVI was weakly associated with the MoCA score after adjusting for time since PVI, baseline MoCA score and other covariates (β (95%CI) 1.19 (0.05; 2.32), p = 0.04). In the propensity matched comparison (n = 352), there was no significant association between PVI and the MoCA score (β (95%CI) 1.04 (-0.19; 2.28), p = 0.1). There were no significant associations between PVI and cognitive function when using the TMT A and B, DSST or SFT independent of the method used.

Conclusion

In this population of AF patients, there was no consistent evidence of an association between PVI and neurocognitive function.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [NCT02105844].

IKACh is constitutively active via PKC epsilon in aging mediated atrial fibrillation

Atrial fibrillation (AF), the most common abnormal heart rhythm, is a major cause for stroke. Aging is a significant risk factor for AF; however, specific ionic pathways that can elucidate how aging leads to AF remain elusive. We used young and old wild-type and PKC epsilon- (PKCϵ) knockout mice, whole animal, and cellular electrophysiology, as well as whole heart, and cellular imaging to investigate how aging leads to the aberrant functioning of a potassium current, and consequently to AF facilitation. Our experiments showed that knocking out PKCϵ abrogates the effects of aging on AF by preventing the development of a constitutively active acetylcholine sensitive inward rectifier potassium current (IKACh). Moreover, blocking this abnormal current in the old heart reduces AF inducibility. Our studies demonstrate that in the aging heart, IKACh is constitutively active in a PKCϵ-dependent manner, contributing to the perpetuation of AF.

Global cognitive performance at 4-year follow-up in individuals with atrial fibrillation-findings from The Irish Longitudinal Study on Ageing

INTRODUCTION

Atrial fibrillation (AF) has been proposed as a risk factor for cognitive impairment, even in the absence of a history of stroke. This study investigates whether AF is associated with increased risk of cognitive decline in a community-dwelling population of adults over the age of 50.

METHODS

Data from the 1st and 3rd waves of The Irish Longitudinal Study on Ageing (TILDA) were used (4-year follow-up period). TILDA is a large prospective cohort study of community-dwelling adults over the age of 50 in Ireland. AF was assessed via electrocardiogram. Global cognitive function was assessed at baseline and follow-up using Montreal Cognitive Assessment (MOCA). Analysis of global cognition was repeated stratifying by age. Mixed-effects Poisson regression was used to assess for change in rate of errors on MOCA and MOCA subdomains.

RESULTS

A total of 3,417 participants were included in the study. Results found that participants with AF had a greater increase in rate of errors on MOCA over 4-year follow-up (incident rate ratio (IRR) 1.18; 95% confidence interval (CI) 1.02, 1.37; P-value 0.023). However, this was no longer significant on controlling for age, sex and level of education (IRR 1.08; 95% CI 0.93, 1.25; P-value 0.332). There was no difference when stratifying by age group, or when separating MOCA into subdomains.

CONCLUSION

Individuals with AF were more likely to show an increase in rate of errors between waves 1 and 3 (4-year follow-up period) in the TILDA population; however, results were not significant when controlling for age, sex and level of education.

Atrial Fibrillation Is Associated with Cognitive Impairment, All-Cause Dementia, Vascular Dementia, and Alzheimer's Disease: a Systematic Review and Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) is a risk factor for cognitive impairment and dementia in patients with stroke history. However, the association between AF and cognitive impairment in broader populations is less clear.

OBJECTIVE

To systematically review and quantitatively synthesize the existing evidence regarding the association of AF with cognitive impairment of any severity and etiology and dementia.

METHODS

Medline, Scopus, and Cochrane Central were searched in order to identify studies investigating the association between AF and cognitive impairment (or dementia) cross-sectionally and longitudinally. Studies encompassing and analyzing exclusively patients with stroke history were excluded. A random-effects model meta-analysis was conducted. Potential sources of between-study heterogeneity were investigated via subgroup and meta-regression analyses. Sensitivity analyses including only studies reporting data on stroke-free patients, vascular dementia, and Alzheimer's disease were performed.

RESULTS

In total, 43 studies were included. In the pooled analysis, AF was significantly associated with dementia (adjusted OR, 1.6; 95% CI, 1.3 to 2.1; I², 31%) and the combined endpoint of cognitive impairment or dementia (pooled adjusted OR, 1.5; 95% CI, 1.4 to 1.8; I², 34%). The results were significant, even when studies including only stroke-free patients were pooled together (unadjusted OR, 2.2; 95% CI, 1.4 to 3.5; I², 96%), but the heterogeneity rates were high. AF was significantly associated with increased risk of both vascular (adjusted OR, 1.7; 95% CI, 1.2 to 2.3; I², 43%) and Alzheimer's dementia (adjusted HR, 1.4; 95% CI, 1.2 to 1.6; I², 42%).

CONCLUSION

AF increases the risk of cognitive impairment, all-cause dementia, vascular dementia, and Alzheimer's disease. Future studies should employ interventions that may delay or even prevent cognitive decline in AF patients.

[Possibilities of sequential levocarnitin and acetylcarnitin treatment in correcting cognitive deficiency in patients with cardiovascular diseases]

OBJECTIVE

To evaluate the effectiveness of sequential therapy with levocarnitine and acetylcarnitine in patients with cardiovascular pathology (arterial hypertension and/or coronary heart disease) and moderate cognitive deficits.

MATERIAL AND METHODS

The study included 120 patients aged 54-67 years. The main group of patients (n=60) in addition to the basic treatment of the underlying disease received l-carnitine (Elkar solution for intravenous and intramuscular injection of 100 mg/ml, the company «PIK-FARMA»)/jet during 10 days in a dose of 1000 mg/day, with following transition to oral administration of acetyl-l-carnitine (Carnitin, the company «PIK-FARMA»), 500 mg (2 cap Sula) 2 times a day for 2 months. The comparison group (n=60) received basic therapy for major diseases. The total duration of follow-up was 70 days.

RESULTS

The results obtained indicate that in such comorbid patients, the use of levocarnitine and acetylcarnitine reduces the severity of cognitive deficits. An important aspect of their pathogenetic effect on the severity of cognitive deficits may be the possibility of correcting endothelial dysfunction. The use of levocarnitine and acetylcarnitine in patients with cardiovascular pathology has demonstrated good tolerability and safety.

Relation of Atrial Fibrillation to Cognitive Decline (from the REasons for Geographic and Racial Differences in Stroke [REGARDS] Study)

The association of atrial fibrillation (AF) with cognitive function remains unclear, especially among racially/geographically diverse populations. This analysis included 25,980 black and white adults, aged 48+, from the national REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, free from cognitive impairment and stroke at baseline. Baseline AF was identified by self-reported medical history or electrocardiogram (ECG). Cognitive testing was conducted yearly with the Six Item Screener (SIS) to define impairment and at 2-year intervals to assess decline on: animal naming and letter fluency, Montreal Cognitive Assessment (MoCA), Word List Learning (WLL) and Delayed Recall tasks (WLD). Multivariable regression models estimated the relationships between AF and baseline impairment and time to cognitive impairment. Models were adjusted sequentially for age, sex, race, geographic region, and education, then cardiovascular risk factors and finally incident stroke. AF was present in 2,168 (8.3%) participants at baseline. AF was associated with poorer baseline performance on measures of: semantic fluency (p<0.01); global cognitive performance (MoCA, p<0.01); and WLD (p<0.01). During a mean follow-up of 8.06 years, steeper declines in list learning were observed among participants with AF (p<0.03) which remained significant after adjusting for cardiovascular risk factors (p<0.04) and incident stroke (p<0.03). Effect modification by race, sex and incident stroke on AF and cognitive decline were also detected. In conclusion, AF was associated with poorer baseline cognitive performance across multiple domains and incident cognitive impairment in this bi-racial cohort. Additional adjustment for cardiovascular risk factors attenuated these relations with the exception of learning.

Framingham Heart Study: JACC Focus Seminar, 1/8

The Framingham Heart Study is the longest-running cardiovascular epidemiological study, starting in 1948. This paper gives an overview of the various cohorts, collected data, and most important research findings to date. In brief, the Framingham Heart Study, funded by the National Institutes of Health and managed by Boston University, spans 3 generations of well phenotyped White persons and 2 cohorts comprised of racial and ethnic minority groups. These cohorts are densely phenotyped, with extensive longitudinal follow-up, and they continue to provide us with important information on human cardiovascular and noncardiovascular physiology over the lifespan, as well as to identify major risk factors for cardiovascular disease. This paper also summarizes some of the more recent progress in molecular epidemiology and discusses the future of the study.

[Atrial fibrillation and impairment of cognition-importance for geriatrics]

According to the current study situation an independent association between atrial fibrillation and cognitive impairment is likely. Several pathomechanisms seem to be causative: embolisms in particular appear to cause clinically inapparent cerebral infarction and thus a deterioration of cognitive status but hypoperfusion and possibly subsequent atrophy of the gray matter can also play a role. There are indications but not yet sufficient evidence for protective effects of anticoagulation, rhythm control and possibly frequency regulation.

Atrial Fibrillation and Cognitive Impairment: An Associated Burden or Burden by Association?

Growing evidence suggests that atrial fibrillation (AF), in addition to its thromboembolic risk, is a risk factor for cognitive impairment (CI) via several pathways and mechanisms, further contributing to morbidity/mortality. Prior stroke is a contributor to CI, but AF is also associated with CI independently from prior stroke. Silent brain infarctions, microemboli and microbleeds, brain atrophy, cerebral hypoperfusion from widely fluctuating ventricular rates, altered hemostatic function, vascular oxidative stress, and inflammation may all exacerbate CI, particularly in patients with persistent/permanent rather than paroxysmal AF and with increased duration/burden of the arrhythmia. Brain magnetic resonance imaging is an important screening tool in eliciting and monitoring vascular and nonvascular lesions contributing to CI. Evidence is also emerging about the role of genetics in CI development. Anticoagulation and rhythm/rate control strategies may protect against CI preventing or slowing its progression or conversion to dementia, particularly at the early stages when CI may still be a treatable condition. Importantly, AF and CI share many common risk factors. Thus, screening for these 2 conditions and searching for and managing modifiable risk factors and potentially reversible causes for both AF and CI remains an important step toward prevention or amelioration of the impact incurred by these 2 conditions.

Atrial Fibrillation and Cognitive Impairment: New Insights and Future Directions

INTRODUCTION

Atrial fibrillation (AF) has been recognised as the most prevalent sustained arrhythmia. Recently, a growing body of evidence has suggested that AF might be involved in the progression of cognitive impairment (CIM), potentially extending into types of dementia. Accordingly, the purpose of the present study was to summarise the findings of investigations examining association between AF and cognitive function as well as highlighting the possible causes of discrepancy between the findings and reviewing the probable mechanisms of CIM in patients affected with AF.

METHODS

A systematic search in the literature was conducted in the databases of PubMed, Scopus, Cochrane Library, and Google Scholar with no language restrictions, using specified search terms to identify studies published between 1 January 1990 and 1 April 2018. Then, study designs, participant information, diagnostic approaches used for cognitive assessments, and incidence/prevalence rates of CIM and/or dementia were assessed.

RESULTS

Out of the initial 2,364 articles retrieved, a total number of 40 studies were selected for data collection. Most studies had suggested a significant relationship between AF and CIM. In this regard, cerebral hypo-perfusion, altered cerebral blood flow, cerebral micro-bleeds, micro-emboli, vascular inflammation, cerebral small vessel diseases, vascular inflammation, and genetic factors were considered as the possible mechanisms of CIM in patients suffering from AF. It seemed that differences in study settings and designs, variations of diagnostic tools for CIM and AF, as well as underlying conditions such as age groups, concurrent chronic diseases, and therapeutic interventions for AF might be amongst probable factors justifying the diversity of findings across the selected articles.

CONCLUSION

Although evidence is much more directed towards an association between AF and CIM, the role of AF in CIM needs to be confirmed in-depth via longer prospective and cohort studies at larger scales using accurate neuropsychological and cognitive function assessments. Moreover, the mechanisms involved in the relationship between AF and Alzheimer's disease (AD) require further studies. To conclude, the effect of different therapeutic strategies of AF on CIM should be investigated in more clinical trials.

Association Between Atrial Fibrillation and Dementia: A Meta-Analysis

Background: A potential evidence from previous epidemiological studies remains conflicting findings regarding the association between atrial fibrillation (AF) and dementia risk. We, therefore, carried out a meta-analysis of relevant studies to investigate the magnitude of the association between AF and dementia risk.

Methods: We performed a systematic literature search of PubMed, EMBASE, and Google Scholar for potential studies between January 1, 1990, and December 31, 2018, with no restriction on the publication language. All potential studies were independently assessed by two reviewers. We only included observational studies that calculated the odds ratio (OR)/hazards ratio (HR) for dementia associated with atrial fibrillation. We first assessed the heterogeneity among study-specific HRs using the Q statistic and I² statistic. We then used the random-effects model to obtain the overall HR and its 95% CI for all studies. We also tested and corrected for publication bias by funnel plot–based methods. The quality of each study was assessed with the Newcastle Ottawa Scale.

Results: A total of 16 studies with 2,415,356 individuals, and approximately 200,653 cases of incidence dementia were included in this study. Patients with AF had a greater risk of incidence dementia than those without AF (random-effect hazard ratio HR: 1.36, 95% CI: 1.23–1.51, p < 0.0001; I² = 83.58). Funnel plot and Egger test did not reveal significant publication bias. However, limitations of the study included high heterogeneity and varying degrees of confounder adjustment across individual studies.

Conclusion: This study serves as added evidence supporting the hypothesis that AF is associated with an increased risk of dementia. More studies are needed to establish whether optimal treatment of AF can reduce or mitigate the risk of dementia.

Cognitive dysfunction in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia in adults, and its incidence and prevalence increase with age. The risk of cognitive impairment and dementia also increases with age, and both AF and cognitive impairment or dementia share important risk factors. In meta-analyses of published studies, AF is associated with a 2.4-fold and 1.4-fold increase in the risk of dementia in patients with or without a history of stroke, respectively. This association is independent of shared risk factors such as hypertension and diabetes mellitus. Neuroimaging has illustrated several potential mechanisms of cognitive decline in patients with AF. AF is associated with increased prevalence of silent cerebral infarcts, and more recent data also suggest an increased prevalence of cerebral microbleeds with AF. AF is also associated with a pro-inflammatory state, and the relationship between AF-induced systemic inflammation and dementia remains to be investigated. Preliminary reports indicate that anticoagulation medication including warfarin can reduce the risk of cognitive impairment in patients with AF. Catheter ablation, increasingly used to maintain sinus rhythm in patients with AF, is associated with the formation of new silent cerebral lesions. The majority of these lesions are not detectable after 1 year, and insufficient data are available to evaluate their effect on cognition. Large prospective studies are urgently needed to confirm the association between AF and dementia, to elucidate the associated mechanisms, and to investigate the effect of anticoagulation and rhythm control on cognition.

Atrial Fibrillation in Older People: Concepts and Controversies

Atrial fibrillation (AF) is the commonest cardiac rhythm abnormality and has a significant disease burden. Amongst its devastating complications is stroke, the risk of which increases with age. The stroke risk in an older person with AF is therefore tremendous, and oral-anticoagulation (OAC) therapy is central to minimizing this risk. The presence of age-associated factors such as frailty and multi-morbidities add complexity to OAC prescription decisions in older patients and often, OAC is needlessly withheld from them despite a lack of evidence to support this practice. Generally, this is driven by an over-estimation of the bleeding risk. This review article provides an overview of the concepts and controversies in managing AF in older people, with respect to the existing evidence and current practice. A literature search was conducted on Pubmed and Cochrane using keywords, and relevant articles published by the 1st of May 2019 were included. The article will shed light on common misconceptions that appear to serve as rationale for precluding OAC and focus on clinical considerations that may aid OAC prescription decisions where appropriate, to optimize AF management using an integrated, multi-disciplinary care approach. This is crucial for all patients, particularly older individuals who are most vulnerable to the deleterious consequences of this condition.

Blinded Randomized Trial of Anticoagulation to Prevent Ischemic Stroke and Neurocognitive Impairment in Atrial Fibrillation (BRAIN-AF): Methods and Design

BACKGROUND

Compelling evidence showing a link between atrial fibrillation (AF) and cognitive decline and dementia is accumulating.

METHODS

Blinded Randomized Trial of Anticoagulation to Prevent Ischemic Stroke and Neurocognitive Impairment in Atrial Fibrillation (BRAIN-AF) is a prospective, multicentric, double-blind, randomized-controlled trial, recruiting patients with nonvalvular AF and a low risk of stroke. Patients with a high risk of bleeding will be excluded from the study. Participants will be randomized to receive either rivaroxaban (15 mg daily) or standard of care (placebo in patients without vascular disease or acetylsalicylic acid 100 mg daily in patients with vascular disease).

RESULTS

The primary outcome is the composite of stroke, transient ischemic attack, and cognitive decline (defined by a decrease in the Montreal Cognitive Assessment score ≥ 3 at any follow-up visit after baseline). Approximately 3250 patients will be enrolled in approximately 130 clinical sites until 609 adjudicated primary outcome events have occurred.

CONCLUSIONS

BRAIN-AF determines whether oral anticoagulation therapy with rivaroxaban compared with standard of care reduces the risk of stroke, transient ischemic attack, or cognitive decline in patients with nonvalvular AF and a low risk of stroke.

Atrial Fibrillation and Risk of Dementia: Epidemiology, Mechanisms, and Effect of Anticoagulation

Atrial fibrillation (AF) is one of the cardiovascular risk factors for dementia. Several longitudinal studies have reported an association between AF and dementia independently of stroke history. Although the mechanisms underlying this association are not fully understood, proposed mechanisms include cerebral hypoperfusion, inflammation, genetic factors, cerebral microbleeds, and recurrent silent cerebral ischemia. Oral anticoagulation can be used to minimize risk of cognitive decline and dementia, given that brain insults can be caused by chronic microemboli or microbleeds. However, controversy on the effects of warfarin and direct oral anticoagulants on this risk exists. This article will address these aspects, with data on the studies already published and a critical view on this subject.

Dementia and Atrial Fibrillation: Pathophysiological Mechanisms and Therapeutic Implications

Atrial fibrillation increases the risk of stroke by a factor of four- to fivefold, and dementia is a common consequence of stroke. However, atrial fibrillation has been associated with cognitive impairment and dementia, even in patients without prior overt stroke. Nonischemic mechanisms include cerebral hypoperfusion, vascular inflammation, brain atrophy, genetic factors, and shared risk factors such as age or hypertension. Critical appraisal of studies evaluating the association between atrial fibrillation and dementia in stroke-free patients reveals that several suffer from methodological issues, such as not including silent stroke or anticoagulation therapy in multivariate analyses. Some studies show a close relationship between atrial fibrillation and dementia due to silent stroke, in the absence of overt stroke. Evidence is accumulating that anticoagulation may be effective to decrease the risk of dementia in atrial fibrillation patients. Overall, the pathogenesis linking atrial fibrillation to dementia is likely multifactorial. Cerebral infarctions, including silent stroke, play a central role. These findings underscore the importance of stroke prevention measures in atrial fibrillation patients.

Anticoagulant use in atrial fibrillation and risk of dementia: review of contemporary knowledge

INTRODUCTION

Atrial fibrillation (AF) is strongly associated with dementia, including idiopathic dementias such as Alzheimer's disease. The relative risk of dementia is highest in AF patients 70 years and younger, and the burden of exposure to arrhythmia appears to underlie part of the risk. Areas covered: Anticoagulation choices and approach influence dementia risk. In warfarin patients, inadequate time spent in therapeutic range is highly associated with the increased dementia risk long-term. This risk is further accentuated with frequent over anticoagulation in patients also receiving aspirin. Direct oral anticoagulant therapies in early observational studies show that there is potential for improving long-term risk of dementia when compared to warfarin, although prospective trials are needed. AF and dementia are end manifestations of systemic disease; a systemic approach is needed with early treatment of shared risk factors to prevent disease presentation altogether. Expert commentary: In this review, we will bring together available data with regards to the link between anticoagulant use for AF and dementia. Anticoagulation initiation timing, use, and efficacy remain critical risk factors for dementia in AF patients and consequently provide opportunities to decrease risk.

Association of Atrial Fibrillation With Cognitive Decline and Dementia Over 20 Years: The ARIC-NCS (Atherosclerosis Risk in Communities Neurocognitive Study)

BACKGROUND

Previous studies have reported that atrial fibrillation (AF) is associated with cognitive decline and dementia. These studies, however, had limited follow-up, were based mostly on white and highly selected populations, and did not account for attrition. We evaluated the association of incident AF with 20-year change in cognitive performance (accounting for attrition) and incident dementia in the ARIC (Atherosclerosis Risk in Communities) Study.

METHODS AND RESULTS

We analyzed data from 12 515 participants (mean age, 56.9 [SD, 5.7] years in 1990-1992; 56% women and 24% black) from 1990 to 1992 through 2011 to 2013. Incident AF was ascertained from study ECGs and hospital discharge codes. Cognitive tests were performed in 1990 to 1992, 1996 to 1998, and 2011 to 2013. Incident dementia was clinician adjudicated. We used generalized estimating equations and Cox proportional hazards models to assess the association of time-dependent AF with change in Z scores of cognitive tests and incident dementia, respectively. During 20 years, 2106 participants developed AF and 1157 participants developed dementia. After accounting for cardiovascular risk factors, including ischemic stroke, the average decline over 20 years in global cognitive Z score was 0.115 (95% confidence interval, 0.014-0.215) greater in participants with AF than in those without AF. Further adjustment for attrition by multiple imputation by chained equations strengthened the association. In addition, incident AF was associated with an increased risk of dementia (hazard ratio, 1.23; 95% confidence interval, 1.04-1.45), after adjusting for cardiovascular risk factors, including ischemic stroke.

CONCLUSIONS

AF is associated with greater cognitive decline and increased risk of dementia, independent of ischemic stroke. Because cognitive decline is a precursor to dementia, our findings prompt further investigation to identify specific treatments for AF that will delay the trajectory of cognitive decline and, thus, prevent dementia in patients with AF.

Atrial fibrillation and cognitive decline in the Framingham Heart Study

BACKGROUND

There is a paucity of longitudinal research investigating the relations between atrial fibrillation (AF) and domain-specific cognitive performance.

OBJECTIVE

The purpose of this study was to investigate the association between AF and cognitive performance cross-sectionally and longitudinally.

METHODS

Eligible participants were dementia- and stroke-free at the time of baseline neuropsychological (NP) assessment and underwent at least 1 additional NP assessment with at least 1-year inter-test interval. AF status was examined as a 2-level variable (prevalent AF, no AF) in cross-sectional analyses and then separately as a 3-level variable (prevalent AF, interim AF, no AF) in longitudinal analyses. We examined the association between AF status and cognitive performance with linear regression. We first adjusted models for age and sex and then for vascular risk factors and apolipoprotein ε4 (APOE4) status.

RESULTS

We studied 2682 participants of the Framingham Heart Study original and offspring cohorts. At the baseline NP assessment, 112 participants (4%) had AF (mean age 72 ± 9 years; 32% women). After adjustment for vascular risk factors and APOE4 status, prevalent AF was significantly associated with poorer attention; sex differences were also noted with men performing worse on tests of abstract reasoning and executive function, while women did better on a measure of executive function. Prevalent AF was significantly associated with longitudinal decline in executive function in the original cohort, and interim AF was significantly associated with longitudinal decline in executive function in the offspring cohort.

CONCLUSION

After accounting for vascular risk factor burden and APOE4 status, AF was associated with a vascular profile of change in cognitive function.

Atrial fibrillation, cognition and dementia: A review

Atrial fibrillation (AF) is one of the most common types of cardiac arrhythmia, particularly among older adults. AF confers a 5-fold risk for thromboembolic stroke as well as a 2-fold higher risk for congestive heart failure, morbidity, and mortality. Although stroke remains an important and impactful complication of AF, recent studies have shown that AF is independently associated with other neurological disorders, including cognitive impairment and dementia, even after adjusting for prior ischemic stroke. We performed a review of the published literature on the association between AF and cognitive status. Further, we reviewed studies investigating the underlying mechanisms for this association and/or reporting the impact of AF treatment on cognitive function. While most published studies demonstrate associations between AF and impaired cognition, no AF treatment has yet been associated with a reduced incidence of cognitive decline or dementia.

Age-related decline in task switching is linked to both global and tract-specific changes in white matter microstructure

Task-switching performance relies on a broadly distributed frontoparietal network and declines in older adults. In this study, they investigated whether this age-related decline in task switching performance was mediated by variability in global or regional white matter microstructural health. Seventy cognitively intact adults (43-87 years) completed a cued-trials task switching paradigm. Microstructural white matter measures were derived using diffusion tensor imaging (DTI) analyses on the diffusion-weighted imaging (DWI) sequence. Task switching performance decreased with increasing age and radial diffusivity (RaD), a measure of white matter microstructure that is sensitive to myelin structure. RaD mediated the relationship between age and task switching performance. However, the relationship between RaD and task switching performance remained significant when controlling for age and was stronger in the presence of cardiovascular risk factors. Variability in error and RT mixing cost were associated with RaD in global white matter and in frontoparietal white matter tracts, respectively. These findings suggest that age-related increase in mixing cost may result from both global and tract-specific disruption of cerebral white matter linked to the increased incidence of cardiovascular risks in older adults. Hum Brain Mapp 38:1588-1603, 2017. © 2016 Wiley Periodicals, Inc.

Association between atrial fibrillation and volumetric magnetic resonance imaging brain measures: Framingham Offspring Study

BACKGROUND

The increased risk of stroke and cognitive impairment associated with atrial fibrillation (AF) is well documented. However, there is a paucity of research investigating the relations between AF and brain morphology.

OBJECTIVE

The purpose of this study was to investigate the association between AF and brain volume measures on magnetic resonance imaging (MRI).

METHODS

The study sample included stroke- and dementia-free participants who attended the Framingham Heart Study offspring cohort 7th examination cycle (1999-2005) and underwent contemporaneous MRI. We examined the association between prevalent AF and brain volume measures (total cerebral volume, frontal lobe volume, temporal lobe volume, temporal horn volume, hippocampal volume, and white matter hyperintensity volume) with linear regression. We first adjusted models for age and sex, and then for vascular risk factors and APOE4.

RESULTS

We studied 2144 individuals (mean age 61.8 ± 9.3 years; 54% women); 73 participants (3.4%) had prevalent AF at the time of MRI. In age- and sex-adjusted models, AF was inversely associated with total cerebral brain volume, frontal brain volume, and temporal brain volume. After further adjustment for vascular risk factors and APOE4, AF remained associated with frontal brain volume.

CONCLUSION

After accounting for vascular risk factor burden, prevalent AF was associated with lobar indexes of vascular brain aging but not with expected white matter changes.

Heart failure and Alzheimer's disease

It has recently been proposed that heart failure is a risk factor for Alzheimer's disease. Decreased cerebral blood flow and neurohormonal activation due to heart failure may contribute to the dysfunction of the neurovascular unit and cause an energy crisis in neurons. This leads to the impaired clearance of amyloid beta and hyperphosphorylation of tau protein, resulting in the formation of amyloid beta plaques and neurofibrillary tangles. In this article, we will summarize the current understanding of the relationship between heart failure and Alzheimer's disease based on epidemiological studies, brain imaging research, pathological findings and the use of animal models. The importance of atherosclerosis, myocardial infarction, atrial fibrillation, blood pressure and valve disease as well as the effect of relevant medications will be discussed.

Morphometry of the hippocampal microvasculature in post-stroke and age-related dementias

Background

Optimal vascular function is vital for prevention of dementia. We hypothesized that elderly post-stroke survivors who preserve cognitive function show unperturbed cerebral microvasculature compared with those who develop dementia.

Methods

Using stereological spherical probe software, we compared the length density (Lv, cumulative vessel length per unit tissue volume) of hippocampal microvessels in post mortem brain tissue from post-stroke survivors, Alzheimer's disease (AD), vascular dementia (VaD) and normal ageing control subjects. We also assessed microvessel diameters in the same subjects. Microvessels were identified by markers of endothelial cells (glucose transporter 1; GLUT1), basement membrane (collagen IV; COL4) and smooth muscle cell α-actin (SMA).

Results

We found increased Lv of both GLUT1 and COL4 immunostained microvessels (P < 0.05) in the hippocampal CA1 region of post-stroke demented (PSD) and AD cases compared with post-stroke nondemented (PSND), control and VaD subjects. However, no changes were apparent in the CA2 region. We also noted significant increase in Lv in the entorhinal cortex of AD compared with PSND and PSD subjects. The mean diameter of microvessels was decreased in PSD, compared with PSND, as well as in AD and VaD compared with controls. Cumulative frequency analysis showed PSND subjects to have significantly greater proportion of microvessels with diameters, ranging from 7 to 12 μm.

Conclusions

An increase in microvascular Lv in AD and PSD suggests either an increase in angiogenesis or the formation of newer microvessel loops in response to cerebral hypoperfusion. The decreased vessel diameters found in AD and VaD suggests increased vasoconstriction in dementia.

Cognitive impairment and cardiovascular diseases in the elderly. A heart-brain continuum hypothesis

The aging population is increasing and, therefore, a higher prevalence of cardiac disease is emerging; including hypertension, coronary artery disease, atrial fibrillation and chronic heart failure. Large cohort studies have revealed a relationship among increased risk for cognitive impairment and dementia in cardiovascular diseases probably due to embolic stroke or chronic cerebral hypoperfusion. Thus, the aim of the present review is to overview the studies that investigate the presence and/or the development of cognitive impairments and dementia in patients with varied types of cardiovascular disease. Finally, a continuum among hypertension, coronary artery disease, atrial fibrillation and chronic heart failure with to the development of cognitive impairment and progression to dementia has been hypothesized.

Current readings: neurocognitive impairment and clinical implications after cardiac surgery

The earliest reports of cardiac surgery literatures reported evidence of neurocognitive decline, highlighted in the 1995 statement of Consensus on assessment of neurobehavioral outcomes after cardiac surgery. Until now, the magnitude and clinical importance of neurocognitive outcomes continues to fluctuate and lack clarity. The aim of this review is to evaluate the contemporary status of neurocognitive outcomes in relation to pre-existing impairment, revascularization strategy, broader cardiovascular pathophysiological processes, and any longer-term clinical implications. Five studies published between 2009 and 2013 were reviewed. A meta-analysis did not find differences between on- and off-pump procedures. In other studies, there was evidence for extensive preoperative neurocognitive impairments. Additional 2 studies showed that longer-term neurocognitive impairment, including dementia, was not dissimilar to nonsurgical patients with cardiovascular disease. Currently, there is no convincing evidence to suggest that cardiac surgery, and cardiopulmonary bypass in particular, has a causal role in progression to dementia, or long-term deficit, independent of pre-existing neurocognitive impairments and cardiovascular disease.