Association of Oral Anticoagulant Type With Risk of Dementia Among Patients With Nonvalvular Atrial Fibrillation

Population Dementia Incidence and Direct Oral Anticoagulant Use in a Representative Population With Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Incidence and prevalence of atrial fibrillation (AF), a risk factor of dementia, have been increasing over time. Oral anticoagulation reduces risk of stroke and other negative outcomes of AF and may reduce dementia health inequities. The objective of this study was to estimate dementia incidence in patients with newly-diagnosed AF and taking an anticoagulant as use of direct oral anticoagulants (DOACs) increased.

METHODS

We used a retrospective cohort design with annual incident AF cohorts of community-dwelling Medicare Fee-for-Service beneficiaries, enrolled in Parts A, B, and D from 2007 to 2017. The sample was limited to beneficiaries aged 67 years and older with incident AF; no prior dementia; and use of anticoagulants warfarin, dabigatran, rivaroxaban, apixaban, or edoxaban in year t.

RESULTS

A total of 1,083,338 beneficiaries were included in the study, 58.5% female, with mean (SD) age 77.2 (6.75) years. Among anticoagulated, incident AF cohorts, use of DOACs increased from 10.6% in their first year of availability (2011) to 41.4% in 2017. Among incident AF cohorts taking any oral anticoagulant, 3-year dementia incidence did not change significantly over the cohorts after adjusting for confounders. For example, incidence was 9.1% (95% CI 8.9-9.4) among White persons diagnosed with AF in 2007 and 2008 and 8.9% (95% CI 8.7-9.1) in 2017. Across cohorts, dementia incidence was consistently highest for Black persons, followed by American Indian/Alaska Native and White persons, and lowest for Asian persons. In 2017, 10.9% (95% CI 10.4-11.3) of Black persons in the cohort developed dementia within 3 years, 9.4% (95% CI 8.0-10.9) of American Indian/Alaska Native, 8.9% (95% CI 8.7-9.1) of White, 8.7% (95% CI 8.2-9.1) of Hispanic, and 6.9% (95% CI 6.4-7.4) of Asian persons. Across race/ethnicity, 3-year stroke risk decreased consistently over time; however, the increasing availability of DOACs did not alter the trend.

DISCUSSION

Increased use of DOACs among incident AF cohorts from 2007 to 2017 was not associated with significant declines in dementia or stroke risk. Consideration of similar stroke and dementia risk, as well as differences in cost, is warranted when weighing the risks and benefits of available oral anticoagulants.

Oral anticoagulants and cognitive impairment in patients with atrial fibrillation: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

This systematic review assesses the likelihood of developing dementia and cognitive impairment in patients with atrial fibrillation (AF) receiving non-vitamin K antagonist oral anticoagulants (NOACs) as opposed to vitamin K antagonists (VKAs).

METHODS

We performed a systematic review with meta-analysis and trial sequential analysis (TSA), which encompassed both randomized controlled trials (RCTs) and observational studies. The objective was to assess the impact of NOACs and VKAs on the incidence of dementia in individuals diagnosed with AF.

RESULTS

Out of 1914 studies that were screened, 31 studies were included in the final analysis, which consisted of nine RCTs or their subsequent post-hoc analyses, in addition to 22 observational studies. The meta-analysis shows that NOACs were associated with a decreased probability of developing dementia of any cause [Rate Ratio (RR): 0.88; 95 % confidence interval (95 % CI): 0.82-0.94], especially in patients below the age of 75 (RR: 0.78; 95 % CI: 0.73-0.84). Consistent patterns were observed across all forms of dementia and cognitive function decline. The overall evidence indicates notable variability in the outcome with a moderate-to-low degree of certainty. The TSA suggests that the total sample size of the included trials (155,647 patients) was significantly smaller than the required information size of 784,692 patients to discern the true effect of NOAC versus VKA in terms of reducing dementia risk.

CONCLUSION

NOACs may reduce the likelihood of developing dementia in patients with AF, particularly in those under the age of 75. This review highlights the urgent necessity for thorough research to determine the efficacy of NOACs in safeguarding cognitive health.

The effect of oral anticoagulants on the incidence of dementia in patients with atrial fibrillation: A systematic review and meta-analysis

Background

Dementia is a recognized complication of atrial fibrillation (AF). Oral anticoagulant (OAC) therapy can potentially be protective against this complication.

Methods

A comprehensive search of MEDLINE and Embase for comparative observational studies reporting the efficacy of OAC therapy for the incidence of dementia in patients with AF was conducted from its inception until March 2023. Studies that had patients with prior use of OAC or with a previous history of dementia were excluded.

Results

A total of 22 studies were included in this review involving 617,204 participants. The pooled analysis revealed that OAC therapy, including direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs), was associated with a reduced incidence of dementia in AF patients. Specifically, compared to non-OAC treatment, OACs demonstrated a significant reduction in dementia incidence (HR 0.68, 95 % CI [0.58, 0.80], p < 0.00001), with similar findings observed for DOACs (HR 0.69, 95 % CI [0.51, 0.94], p = 0.02) and VKAs (HR 0.73, 95 % CI [0.56, 0.95], p = 0.02). The comparison of DOAC vs VKA revealed that DOACs are associated with reduced risk of dementia (HR 0.87, 95 % CI [0.79, 0.96], p = 0.004).

Conclusion

Our SR and meta-analysis showed that the use of OAC therapy is associated with a reduced risk of dementia in individuals with AF. However, our results are limited by the potential influence of confounding bias and significant heterogeneity in the analyses.

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.

Effect of different oral anticoagulants on cognitive function in patients with atrial fibrillation: A Bayesian network meta-analysis

BACKGROUND

Atrial fibrillation (AF) is 1 of the most common types of arrhythmias. At present, the treatment for patients with AF mainly includes oral anticoagulants (OACs). Studies have shown that OACs are associated with cognitive decline in patients with atrial fibrillation; however, there is a lack of relevant evidence. This study used Bayesian network meta-analysis (NMA) to investigate the effects of different oral anticoagulants on cognitive decline in patients with AF.

METHODS

We systematically searched for clinical studies on oral anticoagulants in patients with AF in PubMed, Web of Science, Embase, and the Cochrane Library as of July 3, 2023. Cochrane's randomized controlled trial bias risk assessment tool and the Newcastle-Ottawa Scale were used to assess the bias risk of the included studies. The main outcome measure was decreased cognitive functioning.

RESULTS

Ten studies were included, including 2 RCTs and 7 RCSs, including 882,847 patients with AF. Five oral anticoagulants and 2 anticoagulants were included: VKAs (especially warfarin), Dabigatran, Edoxaban, Rivaroxaban, Apixaban, and Aspirin, Clopidogrel. The results of the mesh meta-analysis showed that VKAs were superior to warfarin in reducing the risk of cognitive decline in patients with AF (OR = -1.19, 95% CI (-2.35, -0.06), P < .05) (Table 5). The top 3 drugs in terms of the probability of reducing the incidence of cognitive impairment in patients with AF with different oral anticoagulants were VKAs (87%), rivaroxaban (62.2%), and dabigatran (60.8%).

CONCLUSION

Based on the results of this study, VKAs may be the best intervention measure for reducing the risk of cognitive decline in patients with AF. Owing to the limitations of this study, more high-quality randomized controlled trials with large sample sizes and multiple centers are required to provide more evidence.

Association evaluations of oral anticoagulants with dementia risk based on genomic and real-world data

BACKGROUND

Several observational studies have suggested that oral anticoagulants (OACs) might reduce the risk of dementia in the elderly, but the evidence is inconclusive. And the consistency of this relationship across different OAC classes and dementia subtypes is still uncertain.

METHODS

To comprehensively evaluate this association, we applied Mendelian randomization (MR) combined with pharmacovigilance analysis. MR was used to assess the associations between genetic proxies for three target genes of OACs (VKORC1, F2, and F10) and dementia, including Alzheimer's disease (AD) and vascular dementia (VaD). This genetic analysis was supplemented with real-world pharmacovigilance data, employing disproportionality analysis for more reliable causal inference.

RESULTS

Increased expression of the VKORC1 gene was strongly associated with increased risk of dementia, especially for AD (OR = 1.28, 95% CI = 1.14-1.43; p value < 0.001). Based on pharmacovigilance data, vitamin K antagonists (VKAs, inhibitors targeting VKORC1) exhibited a protective effect against dementia risk (ROR = 0.43, 95% CI = 0.28-0.67). Additional sensitivity analyses, including different MR models and cohorts, supported these results. Conversely, no strong causal associations of genetically proxied F2 and F10 target genes with dementia and its subtypes were found.

CONCLUSIONS

This study reveals that the inhibition of genetically proxied VKORC1 expression or VKAs exposure is associated with a reduced risk of Alzheimer's dementia. However, there is little evidence to support similar associations with direct oral anticoagulants (F2 inhibitors and F10 inhibitors). Further research is warranted to clinically validate our findings.

Oral anticoagulants: A plausible new treatment for Alzheimer's disease?

Alzheimer's disease (AD) and cardiovascular disease (CVD) are strongly associated. Both are multifactorial disorders with long asymptomatic phases and similar risk factors. Indeed, CVD signatures such as cerebral microbleeds, micro-infarcts, atherosclerosis, cerebral amyloid angiopathy and a procoagulant state are highly associated with AD. However, AD and CVD co-development and the molecular mechanisms underlying such associations are not understood. Here, we review the evidence regarding the vascular component of AD and clinical studies using anticoagulants that specifically evaluated the development of AD and other dementias. Most studies reported a markedly decreased incidence of composite dementia in anticoagulated patients with atrial fibrillation, with the highest benefit for direct oral anticoagulants. However, sub-analyses by differential dementia diagnosis were scarce and inconclusive. We finally discuss whether anticoagulation could be a plausible preventive/therapeutic approach for AD and, if so, which would be the best drug and strategy to maximize clinical benefit and minimize potential risks. LINKED ARTICLES: This article is part of a themed issue From Alzheimer's Disease to Vascular Dementia: Different Roads Leading to Cognitive Decline. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.6/issuetoc.

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.

Direct oral anticoagulants vs vitamin K antagonist on dementia risk in atrial fibrillation: systematic review with meta-analysis

Oral anticoagulation significantly reduces the incidence of dementia in atrial fibrillation patients. However, this protective effect has not been compared between Direct Oral Anticoagulants (DOAC) and Vitamin K antagonists' anticoagulants (VKA). We conducted an electronic search for potentially eligible studies through the bibliographic databases MEDLINE, CENTRAL, ClinicalTrials.gov, EMBASE and Web of Science. The outcome of interest was dementia. Random-effects meta-analysis was performed. Nine observational studies were included and 1,175,609 atrial fibrillation patients were enrolled. DOAC therapy was associated with a significant reduction when compared with patients under VKA therapy (hazard ratio 0.89; 95% confidence interval 0.80-0.99). The grade of confidence of our results was very low due to the risk of bias. DOAC therapy is associated with a significant decrease in the risk of dementia when compared with VKA therapy. However, the low certainty of the evidence along with the paucityof clinical trials dedicated to answering this important question underscores a need for global clinical research initiatives.

A comparison of the effects of NOAC and VKA therapy on the incidence of dementia in patients with atrial fibrillation: A systematic review and meta-analysis

Atrial fibrillation (AF) patients are more susceptible to dementia, but the results about the effect of oral anticoagulants (OACs) on the risk of dementia are not consistent. We hypothesize that OAC is associated with a reduced risk of dementia with AF and that nonvitamin K antagonist oral anticoagulants (NOAC) are superior to vitamin K antagonists (VKA). Four databases were systematically searched until July 1, 2022. Two reviewers independently selected literature, evaluated quality, and extracted data. Data were examined using pooled hazard ratios (HRs) and 95% confidence intervals (CIs). Fourteen research studies involving 910 patients were enrolled. The findings indicated that OACs were associated with a decreased risk of dementia (pooled HR: 0.68, 95% CI: 0.55-0.82, I2  = 87.7%), and NOACs had a stronger effect than VKAs (pooled HR: 0.87, 95% CI: 0.79-0.95, I2  = 72%), especially in participants with a CHA2DS2VASc score ≥ 2 (pooled HR: 0.85, 95% CI: 0.72-0.99). Subgroup analysis demonstrated no statistical significance among patients aged <65 years old (pooled HR: 0.83, 95% CI: 0.64-1.07), patients in "based on treatment" studies (pooled HR: 0.89, 95% CI: 0.75-1.06), or people with no stroke background (pooled HR: 0.90, 95% CI: 0.71-1.15). This analysis revealed that OACs were related to the reduction of dementia incidence in AF individuals, and NOACs were better than VKAs, remarkably in people with a CHA2DS2VASc score ≥ 2. The results should be confirmed by further prospective studies, particularly in patients in "based on treatment" studies aged <65 years old with a CHA2DS2VASc score < 2 or without a stroke background.

Managing older people with atrial fibrillation and preventing stroke: a review of anticoagulation approaches

INTRODUCTION

Oral anticoagulants (OACs) are the cornerstone of stroke prevention in atrial fibrillation (AF), but prescribing decisions in older people are complicated. Clinicians must assess the net clinical benefit of OAC in the context of multiple chronic conditions, polypharmacy, frailty and life expectancy. The under-representation of high-risk, older adult sub-populations in clinical trials presents the challenge of choosing the right OAC, where a 'one-size-fits-all' approach cannot be taken.

AREAS COVERED

This review discusses OAC approaches for stroke prevention in older people with AF and presents a prescribing aid to support clinicians' decision-making. High-risk older adults with multiple chronic conditions, specifically chronic kidney disease, dementia/cognitive impairment, previous stroke/transient ischemic attack or intracranial hemorrhage, polypharmacy, frailty, low body weight, high falls risk, and those aged ≥75 years are considered.

EXPERT OPINION

Non-vitamin K antagonist OACs are the preferred first-line OAC in older adults with AF, including high-risk subpopulations, after individual assessment of stroke and bleeding risk, except those with mechanical heart valves and moderate-to-severe mitral stenosis. Head-to-head comparisons of NOACs are not available, therefore the choice of drug (and dose) should be based on an individual's risk (stroke and bleeding) and incorporate their treatment preferences. Treatment decisions must be person-centered and principles of shared decision-making applied.

Anticoagulants and Dementia: A Systematic Review

Many patients diagnosed with atrial fibrillation (AF) develop dementia. Most AF patients are also prescribed some antithrombotic medication to reduce the incidence of stroke, as clots can form within the left atrium. Some research has found that, excluding patients who have experienced strokes, anticoagulants may serve as protective agents against dementia in AF. This systematic review aims to analyze the incidence of dementia in patients who were prescribed anticoagulants. A comprehensive literature review was conducted using the databases PubMed, ProQuest, and ScienceDirect. Only experimental studies and meta-analyses were chosen. The search included the keywords "dementia and anticoagulant" and "cognitive decline and anticoagulants". Our initial search generated 53,306 articles, which were narrowed down to 29 by applying strict inclusion and exclusion algorithms. There was a decreased risk of dementia in patients who had been prescribed oral anticoagulants (OACs) in general, but only studies investigating direct oral anticoagulants OACs (DOACs) suggested that they were protective against dementia. Vitamin K antagonist (VKA) anticoagulants showed conflicting results, with some studies indicating they might increase the risk for dementia, while others suggested that they are protective against it. Warfarin, a specific VKA, was mainly shown to reduce the risk of dementia but was not as effective as DOACs or other OACs. Lastly, it was found that antiplatelet therapy may increase the risk of dementia in AF patients.

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.

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.

Protective Effects of Rivaroxaban on White Matter Integrity and Remyelination in a Mouse Model of Alzheimer's Disease Combined with Cerebral Hypoperfusion

BACKGROUND

Alzheimer's disease (AD) is characterized by cognitive dysfunction and memory loss that is accompanied by pathological changes to white matter. Some clinical and animal research revealed that AD combined with chronic cerebral hypoperfusion (CCH) exacerbates AD progression by inducing blood-brain barrier dysfunction and fibrinogen deposition. Rivaroxaban, an anticoagulant, has been shown to reduce the rates of dementia in atrial fibrillation patients, but its effects on white matter and the underlying mechanisms are unclear.

OBJECTIVE

The main purpose of this study was to explore the therapeutic effect of rivaroxaban on the white matter of AD+CCH mice.

METHODS

In this study, the therapeutic effects of rivaroxaban on white matter in a mouse AD+CCH model were investigated to explore the potential mechanisms involving fibrinogen deposition, inflammation, and oxidative stress on remyelination in white matter.

RESULTS

The results indicate that rivaroxaban significantly attenuated fibrinogen deposition, fibrinogen-related microglia activation, oxidative stress, and enhanced demyelination in AD+CCH mice, leading to improved white matter integrity, reduced axonal damage, and restored myelin loss.

CONCLUSIONS

These findings suggest that long-term administration of rivaroxaban might reduce the risk of dementia.

Risk Factors for Dementia in Patients With Atrial Fibrillation

Although dementia and atrial fibrillation (AF) are common in older adults, risk factors for dementia have not been sufficiently characterized in patients with AF. We studied 621,773 patients with AF without dementia at the time of AF diagnosis who were enrolled in the MarketScan Commercial and Medicare Supplemental databases from 2007 to 2015. Dementia incidence and presence of predictors at the time of AF diagnosis (cardiometabolic conditions, mental and neurologic disorders, and other chronic conditions) were based on International Classification of Diseases, Ninth Revision, Clinical Modification codes in outpatient and inpatient claims, whereas medication usage was based on outpatient pharmacy claims. A frailty score was calculated using a previously established algorithm. The associations between the predictors of interest and dementia were assessed with multivariable Cox models. Patients had a mean age of 68 years (SD 14 years) and 41% were women. During a mean follow-up of 2.0 years, there were 16,073 cases of dementia. The strongest predictors of dementia were frailty (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.40 to 1.45, per 1-SD increase in the score), cognitive impairment (HR 1.50, 95% CI 1.36 to 1.65), mood disorders (HR 1.49, 95% CI 1.32 to 1.70), schizophrenia (HR 1.86, 95% CI 1.75 to 1.98), and substance abuse (HR 1.58, 95% CI 1.39 to 1.80). Among cardiometabolic conditions, only stroke (HR 1.17, 95% CI 1.13 to 1.22) and diabetes mellitus (HR 1.14, 95% CI 1.11 to 1.18) were associated with small increases in dementia risk after adjusting for demographics, frailty, co-morbidities, and medications. We have identified several risk factors for dementia in patients with AF.

Impact of Medication Adherence on the Association Between Oral Anticoagulant Use and Risk of Dementia: A Retrospective Cohort Study using the Japanese Claims Database

Background

Atrial fibrillation (AF) is a major risk factor for the development of stroke and silent cerebral infarct (SCI). Additionally, AF is independently associated with neurological disorders, including cognitive impairment and dementia. Although oral anticoagulants (OACs) are used to reduce the risk of development of stroke and SCI in patients with AF, it is unclear whether OACs reduce the risk of dementia.

Objective

This study aimed to investigate the association between OAC use and dementia in relatively young patients with AF. Moreover, the impact of medication adherence on the association between OAC use and the risk of dementia was examined.

Patients and Methods

This retrospective cohort study was conducted using a large claims database—Japan Medical Data Center, Inc. (JMDC)—from which newly diagnosed patients with AF younger than 75 years of age were identified. We analyzed medication adherence using the medication possession ratio (MPR). The dementia risk was compared between the OAC and non-OAC groups using Cox proportional hazards regression analysis and the Kaplan–Meier method after propensity score matching. Similarly, the MPR-classified and non-OAC groups were also compared.

Results

OAC administration was not associated with the risk of dementia in the entire cohort (hazard ratio [HR] 0.66, 95% confidence interval [CI] 0.40–1.08; p = 0.098); however, OAC administration in patients with an MPR ≥90% was significantly associated with a lower risk of dementia (HR 0.45, 95% CI 0.25–0.81; p = 0.008). Meanwhile, direct OAC (DOAC) and warfarin (WF) administration was not associated with the risk of dementia regardless of MPR. Kaplan–Meier analysis revealed a significant difference in the incidence of dementia between the MPR ≥ 90% OAC and non-OAC groups (log-rank test: p = 0.006). However, no difference was observed in the incidence of dementia between the MPR ≥ 90% WF and non-OAC groups, or between the MPR ≥ 90% DOAC and non-OAC groups.

Conclusions

OAC administration was not associated with the risk of dementia in relatively young patients with AF; however, when limited to patients with an MPR ≥ 90%, OAC administration reduced the risk of dementia. Our results suggest that the association between OAC use and dementia should be evaluated while considering medication adherence.

[Modern issues of improving the prognosis in patients with atrial fibrillation after ischemic stroke]

The anticoagulant therapy with a priority of direct oral anticoagulants is an approach to the prevention of recurrent stroke in patients with atrial fibrillation (AF) that has presently proved its efficacy and is stated in international clinical guidelines. An extensive evidence-based database demonstrates advantages of rivaroxaban over other drugs of this class in secondary prevention of stroke in AF. Furthermore, these advantages are combined with the optimal safety profile. The rivaroxaban treatment may provide the most favorable prognosis due to the prevention of recurrent stroke in AF, reducing the rate of kidney disease progression, and slowing vascular atherosclerosis. An important beneficial feature of rivaroxaban is once-a-day intake, which is important in the context of a high incidence of cognitive disorders in this patient category, and may improve their compliance and, thus, help achieving the expected profile of treatment efficacy. Thus, rivaroxaban can be regarded as a drug of choice for secondary prevention of stroke in AF.

Oral Anticoagulant Treatment and the Risk of Dementia in Patients With Atrial Fibrillation: A Population-Based Cohort Study

Background

We compared the dementia incidence rate between users and nonusers of oral anticoagulants (OACs) in a large cohort of primary care patients with atrial fibrillation.

Methods and Results

We performed a retrospective study using an Australia‐wide primary care data set, MedicineInsight. Patients aged ≥18 years and newly diagnosed with atrial fibrillation between January 1, 2010, and December 31, 2017, and with no recorded history of dementia or stroke were included and followed until December 31, 2018. We applied a propensity score for 1:1 pair matching of baseline covariates and Cox regression for comparing the dementia incidence rates for OAC users and nonusers. Data were analyzed for 18 813 patients with atrial fibrillation (aged 71.9±12.6 years, 47.1% women); 11 419 had a recorded OAC prescription for at least 80% of their follow‐up time. During the mean follow‐up time of 3.7±2.0 years, 425 patients (2.3%; 95% CI, 2.1%–2.5%) had a documented diagnosis of dementia. After propensity matching, the incidence of dementia was significantly lower in OAC users (hazard ratio [HR], 0.59; 95% CI, 0.44–0.80; P<0.001) compared with nonusers. Direct‐acting oral anticoagulant users had a lower incidence of dementia than non‐OAC users (HR, 0.49; 95% CI, 0.33–0.73; P<0.001) or warfarin users (HR, 0.46; 95% CI, 0.28–0.74; P=0.002). No significant difference was seen between warfarin users and non‐OAC users (HR, 1.08; 95% CI, 0.70–1.70; P=0.723).

Conclusions

In patients with atrial fibrillation, direct‐acting oral anticoagulant use may result in a lower incidence of dementia compared with treatment with either warfarin or no anticoagulant.

Direct Oral Anticoagulants and Warfarin for Atrial Fibrillation Treatment: Rural and Urban Trends in Medicare Beneficiaries

BACKGROUND

Data are needed on the use of oral anticoagulation in patients with atrial fibrillation (AF) in rural versus urban areas, including the initiation of direct oral anticoagulants (DOACs).

OBJECTIVE

We used Medicare data to examine rural/urban differences in anticoagulation use in patients with AF.

METHODS

We identified incident AF in a 20% sample of fee-for-service Medicare beneficiaries (aged ≥ 65 years) from 2011 to 2016 and collected ZIP code and covariates at the time of AF. We identified the first anticoagulant prescription filled, if any, following AF diagnosis. We categorized beneficiaries into four rural/urban areas using rural-urban commuting area codes and used Poisson regression models to compare anticoagulant use.

RESULTS

We included 447,252 patients with AF (mean age 79 ± 8 years), of which 82% were urban, 9% large rural, 5% small rural, and 4% isolated. The percentage who initiated an anticoagulant rose from 34% in 2011 to 53% in 2016, paralleling the uptake of DOACs. In a multivariable-adjusted analysis, those in rural areas (vs. urban) were more likely to initiate an anticoagulant. However, rural beneficiaries (vs. urban) were less likely to initiate a DOAC; those in isolated areas were 17% less likely (95% confidence interval [CI] 13-20), those in small rural areas were 12% less likely (95% CI 9-15), and those in large rural areas were 10% less likely (95% CI 8-12).

CONCLUSION

Among Medicare beneficiaries with AF, anticoagulation use was low but increased over time with the introduction of DOACs. Rural beneficiaries were less likely to receive a DOAC.

Effects of Dabigatran on Dementia Pathogenesis and Neuropsychological Function: A Review

BACKGROUND

Patients with atrial fibrillation (AF) carry higher risks of cognitive consequences and psychological burden. An optimal anticoagulant therapy would be expected to better preserve neuropsychological function in addition to effective prevention of stroke and systemic thromboembolism.

OBJECTIVE

The aim of this review is to explore the effects of the non-vitamin K antagonist oral anticoagulant (NOAC) dabigatran, a direct thrombin inhibitor, on cognitive and psychological function as well as dementia pathogenesis.

METHODS

We performed a comprehensive search of PubMed/Medline for all types of relevant articles using a combination of dabigatran and associated keywords updated to August 31, 2021. All titles and abstracts were screened for eligibility, and potentially relevant papers were collected for inclusion.

RESULTS

The pooled results demonstrated neutral to positive impacts of dabigatran on cognitive and psychological outcomes, including laboratory results in animal models of Alzheimer's disease, and reduced incidences of anxiety/depression and dementia for AF patients. Dabigatran also exhibited better therapeutic profiles than warfarin in preclinical and observational research.

CONCLUSION

Given limited strength of evidence from heterogeneous studies, our review proposed modest beneficial effects of dabigatran on neuropsychological function. Further clinical trials are warranted to affirm the pleiotropic protective effects of NOACs on dementia treatment.

Comparative Safety and Effectiveness of Sotalol Versus Dronedarone After Catheter Ablation for Atrial Fibrillation

Background Atrial tachyarrhythmias are common after atrial fibrillation ablation, so adjunctive antiarrhythmic drug therapy is often used. Data on the effectiveness and safety of dronedarone and sotalol after AF ablation are limited. Here, we compared health outcomes of ablated patients treated with dronedarone versus sotalol. Methods and Results A comparative analysis of propensity score-matched retrospective cohorts was performed using IBM MarketScan Research Databases. Patients treated with dronedarone after atrial fibrillation ablation were matched 1:1 to patients treated with sotalol between January 1, 2013 and March 31, 2018. Outcomes of interest included cardiovascular hospitalization, proarrhythmia, repeat ablation, and cardioversion. This study was exempt from institutional review board review. Among 30 696 patients who underwent atrial fibrillation ablation, 2086 were treated with dronedarone and 3665 with sotalol after ablation. Propensity-score matching resulted in 1815 patients receiving dronedarone matched 1:1 to patients receiving sotalol. Risk of cardiovascular hospitalization was lower with dronedarone versus sotalol at 3 months (adjusted hazard ratio [aHR], 0.77 [95% CI, 0.61-0.97]), 6 months (aHR, 0.76 [95% CI, 0.63-0.93]), and 12 months after ablation (aHR, 0.70 [95% CI, 0.66-0.93]). Risk of repeat ablation and cardioversion generally did not differ between the 2 groups. A lower risk of proarrhythmia was associated with dronedarone versus sotalol at 3 months (aHR, 0.76 [95% CI, 0.64-0.90]), 6 months (aHR, 0.80 [95% CI, 0.70-0.93]), and 12 months (aHR, 0.83 [95% CI, 0.73-0.94]) after ablation. Conclusions These data suggest that dronedarone may be a more effective and safer alternative after ablation than sotalol.

[Atrial fibrillation and cognitive impairment: features of the relationship, developmental and prevention mechanisms]

The article discusses the development of cognitive deficit in patients with atrial fibrillation (AF) and provides data on mechanisms of the development of cognitive disorders in AF. Under discussion are a possibility of reducing the risk of cognitive disorders with the anticoagulant therapy for prevention of stroke in AF and different properties of different anticoagulants, which may be important for patients. Thus, patients with cognitive disorders are more prone to missing the dose, which may entail serious, possibly fatal consequences. Therefore, the convenience of dosing may be essential. The drug rivaroxaban that has once-a-day dosing schedule and a calendar package, may help the patient better adhere to the doctor's recommendations. Therefore, rivaroxaban may help improving the compliance, which is the major condition for comprehensive, necessary protection of an elderly patient with AF, including the protection, with high safety, from stroke, from the risk of coronary complications, and from the impairment of kidney function.

Protective Effect of Rivaroxaban Against Amyloid Pathology and Neuroinflammation Through Inhibiting PAR-1 and PAR-2 in Alzheimer's Disease Mice

BACKGROUND

Recent studies have revealed that atrial fibrillation (AF) patients have a high risk of developing cognitive impairment, vascular dementia, and Alzheimer's disease (AD). Some reports suggest that the application of oral anticoagulant with an appropriate dose may have a preventive effect on AD. However, which oral anticoagulant drug is more appropriate for preventing AD and the underlying mechanism(s) is still unknown.

OBJECTIVE

The aim of the present study was to assess the treatment effect of rivaroxaban administration as well as investigate the roles of PAR-1 and PAR-2 in the AD + CAA mice model.

METHODS

In the present study, we compared a traditional oral anticoagulant, warfarin, and a direct oral anticoagulant (DOAC), rivaroxaban, via long-term administration to an AD with cerebral amyloid angiopathy (CAA) mice model.

RESULTS

Rivaroxaban treatment attenuated neuroinflammation, blood-brain barrier dysfunction, memory deficits, and amyloid-β deposition through PAR-1/PAR-2 inhibition in the AD + CAA mice model compared with warfarin and no-treatment groups.

CONCLUSION

The present study demonstrates that rivaroxaban can attenuate AD progress and can be a potential choice to prevent AD.

Lower dementia risk with anticoagulation and ablation in patients with atrial fibrillation

Atrial fibrillation (AF), the most common cardiac arrhythmia in the elderly population, has been associated with an impairment of cognitive function and an increased risk of dementia. Even though there does not appear to be solid evidence that any specific treatment prevents or delays AF-associated cognitive decline, evidence is accumulating regarding the possible treatment strategies for preventing dementia. Oral anticoagulation, especially non-vitamin K antagonist oral anticoagulants rather than warfarin use, has been suggested to be associated with reduced risk of dementia. Successfully maintaining sinus rhythm using catheter ablation might be also helpful in preventing subsequent dementia in patients with AF. In this review, we critically appraise the proposed treatment strategies for preventing AF-associated cognitive decline.

Comparing Warfarin and 4 Direct Oral Anticoagulants for the Risk of Dementia in Patients With Atrial Fibrillation

Background and Purpose

Atrial fibrillation is a risk factor for dementia, and oral anticoagulant use is associated with a decreased risk of dementia in patients with atrial fibrillation. We aimed to investigate whether the risk of dementia would be different between patients treated with direct oral anticoagulants (DOACs) compared with those with warfarin.

Methods

Using the Korean nationwide claims database from January 2014 to December 2017, we identified oral anticoagulant–naive nonvalvular atrial fibrillation patients aged ≥40 years. For the comparisons, warfarin and DOAC groups were balanced using the inverse probability of treatment weighting method. The primary outcome was incident dementia.

Results

Among 72 846 of total study patients, 25 948 were treated with warfarin, and 46 898 were treated with DOAC (17 193 with rivaroxaban, 9882 with dabigatran, 11 992 with apixaban, and 7831 with edoxaban). During mean 1.3±1.1 years of follow-up, crude incidence of dementia was 4.87 per 100 person-years (1.20 per 100 person-years for vascular dementia and 3.30 per 100 person-years for Alzheimer dementia). Compared with warfarin, DOAC showed a comparable risks of dementia, vascular dementia, and Alzheimer dementia. In subgroup analyses, DOAC was associated with a lower risk of dementia than warfarin, particularly in patients aged 65 to 74 years (hazard ratio, 0.815 [95% CI, 0.709–0.936]) and in patients with prior stroke (hazard ratio, 0.891 [95% CI, 0.820–0.968]). When comparing individual DOACs with warfarin, edoxaban was associated with a lower risk of dementia (hazard ratio, 0.830 [95% CI, 0.740–0.931]).

Conclusions

In this large Asian population with atrial fibrillation, DOAC showed a comparable risk of dementia with warfarin overall. DOACs appeared more beneficial than warfarin, in those aged 65 to 74 years or with a history of stroke. For specific DOACs, only edoxaban was associated with a lower risk of dementia than warfarin.

Association of anticoagulant therapy with risk of dementia among patients with atrial fibrillation

AIMS

To investigate the risk of dementia in atrial fibrillation (AF) patients treated with different oral anticoagulants (OACs).

METHODS AND RESULTS

This observational, population-based cohort study enrolled 53 236 dementia-free individuals with non-valvular AF who were aged ≥50 years and newly prescribed OACs from 1 January 2013 to 31 December 2016 from the Korean National Health Insurance Service database. Propensity score matching was used to compare the rates of dementia between users of non-vitamin K antagonist oral anticoagulant (NOAC) (dabigatran, rivaroxaban, and apixaban) and warfarin and to compare each individual NOAC with warfarin. Propensity score weighting analyses were also performed. In the study population (41.3% women; mean age: 70.7 years), 2194 had a diagnosis of incident dementia during a mean follow-up of 20.2 months. Relative to propensity-matched warfarin users, NOAC users tended to be at lower risk of dementia [hazard ratio (HR) 0.78, 95% confidence interval (CI) 0.69-0.90]. When comparing individual NOACs with warfarin, all the three NOACs were associated with lower dementia risk. In pairwise comparisons among NOACs, rivaroxaban was associated with decreased dementia risk, compared with dabigatran (HR 0.83, 95% CI 0.74-0.92). Supplemental propensity-weighted analyses showed consistent protective associations of NOACs with dementia relative to warfarin. The associations were consistent irrespectively of age, sex, stroke, and vascular disease and more prominent in standard dose users of NOAC.

CONCLUSION

In this propensity-matched and -weighted analysis using a real-world population-based cohort, use of NOACs was associated with lower dementia risk than use of warfarin among non-valvular AF patients initiating OAC treatment.

Atrial fibrillation and Alzheimer's disease: A conundrum

During ageing, the prevalence of Alzheimer's disease (AD) and of cardiovascular disease CVD) increases. Our aim is to investigate the relationship between AD and CVD and its risk factors, with a view to explaining the underlying mechanisms of this association. This review is based on the material obtained via MEDLINE (PubMed), Embase and Clinical Trials databases, from January 1980 until May 2019. The search term used was "Alzheimer's disease", combined with "cardiovascular disease", "hypertension", "dyslipidaemia", "diabetes mellitus", "atrial fibrillation", "coronary artery disease", "heart valve disease", "heart failure". Out of the 1328 papers initially retrieved, 431 duplicates and 216 records in languages other than English were removed; thus, only 98 papers were included in our research material. We have found that AD and CVD are frequently associated, while both of them, alone may be considered deleterious to health, the study of their combination constitutes a clinical challenge. Further research will help to clarify the real impact of CVD and its risk factors on AD, in order to better comprehend the effects of subclinical and clinical cardiovascular diseases on the brain. It may be hypothesized that there are various mechanisms underlying the association between AD and CVD, the main ones being: hypoperfusion and emboli, atherosclerosis, furthermore in both the heart and brain of AD patients, amyloid deposits may be present, thus causing damage to these organs. We need to clarify the real impact of these underlying hypothesized mechanisms and to investigate gender issues.

Association between Circulating Protein C Levels and Incident Dementia: The Atherosclerosis Risk in Communities Study

INTRODUCTION

Hemostasis depends on the delicate balance between coagulants and anticoagulants. Higher levels of circulating coagulants have been associated with higher risk of cerebral infarctions and dementia. In contrast, higher levels of circulating protein C, an endogenous anticoagulant, have been associated with lower risk of cerebral infarctions, and the association between protein C levels and the risk of dementia is unknown. The goal of this study was to evaluate the association of circulating protein C levels in midlife and late life with incident dementia.

METHODS

Circulating protein C levels were measured using blood samples collected at the midlife baseline (1987-1989) and the late-life baseline (2011-2013) among 14,462 and 3,614 participants, respectively, in the Atherosclerosis Risk in Communities study. Protein C levels were measured using enzyme-linked immunosorbent assay at midlife and a modified aptamer-based assay at late life. Participants were followed up to 2013 from midlife and up to 2017 from late life. Incident dementia was ascertained during the follow-up periods using in-person cognitive and functional assessment, informant interviews, and International Classification of Diseases codes at hospitalization discharge and on death certificates. Cause-specific Cox regression models were used to evaluate the association between quintiles of circulating protein C and incident dementia.

RESULTS

From midlife (mean age of 54), 1,389 incident dementia events were observed over a median follow-up of 23 years. From late life (mean age of 75), 353 incident dementia events were observed over a median follow-up of 4.9 years. At both midlife and late life, circulating protein C had an inverse association with incident dementia after adjusting for demographic, vascular, and hemostatic risk factors, incident stroke as time-dependent covariate, and incorporating stabilized weights based on propensity scores (quintile 5 vs. quintile 1 as the reference, midlife hazard ratio 0.80, 95% confidence interval 0.66-0.96, p value for trend 0.04; late-life hazard ratio 0.84, 95% confidence interval: 0.55-1.28, p value for trend 0.04).

DISCUSSION/CONCLUSION

Circulating protein C has an inverse association with incident dementia independent of established risk factors, including stroke. Our results suggest studying anticoagulants in addition to coagulants can increase our understanding on the relationship between hemostasis and dementia.

Association of Type of Antidepressant Initiation with Bleeding Risk in Atrial Fibrillation Patients Taking Oral Anticoagulants

Background

Inconsistent evidence suggests that use of certain antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), in patients using oral anticoagulants (OACs) might be associated with an elevated risk of bleeding.

Objective

This study aims to investigate the risk of bleeding associated with initiation of different types of antidepressants among atrial fibrillation (AF) patients on OAC therapy.

Patients and methods

A total of 30,336 AF patients (mean age 72.2 years; 54% female) on OAC therapy that started antidepressant treatment were identified from the Truven Health Analytics MarketScan Commercial and Medicare Databases for the period 2007–2015. Exposure was defined as filling a prescription for antidepressant, and categorized as SSRI, serotonin/norepinephrine reuptake inhibitors (SNRIs), serotonin reuptake inhibitors (SRIs), tricyclic antidepressants (TCAs), or other antidepressants. The primary outcome was incident hospitalized bleeding. Associations of antidepressant type with bleeding were assessed calculating hazard ratios (HRs) and 95% confidence intervals (CIs) with adjusted Cox models in pairwise propensity score-matched cohorts.

Results

During a mean follow-up of 21 months, we identified 1612 bleeding episodes. In pairwise comparisons, SSRI use was associated with an increased risk of bleeding when compared to most other antidepressants (HR 1.22, 95% CI 0.96–1.54 vs SNRI; HR 1.10, 95% CI 0.90–1.35 vs SRI; HR 1.03, 95% CI 0.82–1.30 vs TCA). SNRI use was associated with the lowest bleeding risk. Results did not differ by OAC type, age, and sex.

Conclusions

Among AF patients on OAC initiating antidepressants, risk of bleeding varied across antidepressant type. This information can inform treatment choices among patients receiving OAC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00258-3.

Impact of Oral Anticoagulation Therapy Versus Left Atrial Appendage Occlusion on Cognitive Function and Quality of Life in Patients With Atrial Fibrillation

Background

We compared the cognitive status and quality of life in patients with atrial fibrillation undergoing left atrial appendage occlusion (LAAO) or remaining on oral anticoagulation (OAC) after atrial fibrillation ablation.

Methods and Results

Cognition was assessed by the Montreal Cognitive Assessment (MoCA) survey at baseline and follow‐up. Consecutive patients receiving LAAO or OAC after atrial fibrillation ablation were screened, and patients with a score of ≤17 were excluded from the study. Quality of life was measured at baseline and 1 year using the Atrial Fibrillation Effect on Quality of Life survey. A total of 50 patients (CHA₂DS₂‐VASc [congestive heart failure, hypertension, age≥75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65–74 years, sex category] score: 3.30±1.43) in the LAAO group and 48 (CHA₂DS₂‐VASc score 2.73±1.25) in the OAC group were included in this prospective study. Mean baseline MoCA score was 26.18 and 26.08 in the LAAO and OAC groups, respectively (P=0.846). At 1 year, scores were 26.94 and 23.38 in the respective groups. MoCA score decreased by an estimated −2.74 (95% CI, −3.61 to −1.87; P<0.0001) points in the OAC group, whereas the change in the LAAO group was nonsignificant (0.79; (95% CI, −0.06 to 1.64; P=0.07). After adjusting for baseline clinical characteristics, remaining on OAC was an independent predictor of MoCA change at 1 year (regression coefficient, −3.38; 95% CI, −4.75 to −2.02; P<0.0001). Change in Atrial Fibrillation Effect on Quality of Life score did not differ significantly in achieving a clinically important difference between groups.

Conclusions

In this series, a significant difference in the postprocedure MoCA score was observed in postablation patients with atrial fibrillation receiving LAAO versus remaining on OAC with a substantial decline in the score in the OAC group. However, quality of life improved similarly across groups.

Registration

https://www.ClinicalTrials.gov. Unique identifier: NCT01816308

Outcome of older hip fracture patients on anticoagulation: a comparison of vitamin K-antagonists and Factor Xa inhibitors

INTRODUCTION

Older hip fracture patients are still challenging in daily clinical practice. Due to the high prevalence of osteoporosis and atrial fibrillation in this age group, the number of fragility fracture patients under oral anticoagulation (OAC) increases. The outcome is still disappointing, short- and long-term mortality and morbidity is high. The impact of pre-existing OAC is not yet clear, especially regarding new OAC drugs like Factor Xa inhibitors (FXa). The purpose of our study was to compare the short-term outcome of older hip fracture patients, without OAC (controls), on Vitamin K antagonists (VKA) and on FXa.

MATERIALS AND METHODS

The study is a retrospective case-control study including patients older than 70 years who sustained hip fractures caused by an inadequate trauma and treated at a level 1 trauma center from February 2017 to June 2018. Patient's information was taken from patient's charts. 102 cases were analysed, 61 controls, 41 on OAC (15 on VKA and 26 on FXa). As outcome parameter we defined mortality, perioperative complications, bleeding, need of blood supplements, delay of surgery, length of stay, and a combined outcome parameter (mortality, myocardial infarction, stroke, thromboembolic events, blood preservations, re-vision surgery, major bleeding and decline of hemoglobin).

RESULTS

Eight patients died during hospital stay, in-hospital mortality was 7.8%. The highest mortality rate was found in patients on VKA (20%), compared to patients on FXa (3.8%) and controls (6.6%). However, mortality rate did not differ significantly within the groups. The combined endpoint was significantly more frequently seen in patients on OAC compared to controls (p = 0.006). No difference was observed between patients on VKA or FXa. Mean time to surgery and LOS was significantly longer in patients on OAC compared to controls. No significant differences were seen between VKA and FXa.

CONCLUSIONS

In our study OAC was significantly associated with worse outcome compared to controls. Marginal differences were observed between patients on FXa or VKA. Further studies involving a higher number of patients are necessary to confirm our results. At that time, some our results have to interpreted carefully and need confirmation.

New Avenues for Optimal Treatment of Atrial Fibrillation and Stroke Prevention

One in 3 individuals free of atrial fibrillation (AF) at index age 55 years is estimated to develop AF later in life. AF increases not only the risk of ischemic stroke but also of dementia, even in stroke-free patients. In this review, we address recent advances in the heart-brain interaction with focus on AF. Issues discussed are (1) the timing of direct oral anticoagulants start following an ischemic stroke; (2) the comparison of direct oral anticoagulants versus vitamin K antagonists in early secondary stroke prevention; (3) harms of bridging with heparin before direct oral anticoagulants; (4) importance of appropriate direct oral anticoagulants dosing; (5) screening for AF in high-risk populations, including the role of wearables; (6) left atrial appendage occlusion as an alternative to oral anticoagulation; (7) the role of early rhythm-control therapy; (8) effect of lifestyle interventions on AF; (9) AF as a risk factor for dementia. An interdisciplinary approach seems appropriate to address the complex challenges posed by AF.

Lower Risk of Dementia in Patients With Atrial Fibrillation Taking Non-Vitamin K Antagonist Oral Anticoagulants: A Nationwide Population-Based Cohort Study

Background A higher risk of developing dementia is observed in patients with atrial fibrillation (AF). Results are inconsistent regarding the risk of dementia when patients with AF use different anticoagulants. We aimed to investigate the risk of dementia in patients with AF receiving non-vitamin K antagonist oral anticoagulants (NOACs) compared with those receiving warfarin. Methods and Results We conducted a nationwide population-based cohort study of incident cases using the Taiwan National Health Insurance Research Database. We initially enlisted all incident cases of AF and then selected those treated with either NOACs or warfarin for at least 90 days between 2012 and 2016. First-ever diagnosis of dementia was the primary outcome. We performed propensity score matching to minimize the difference between each cohort. We used the Fine and Gray competing risk regression model to calculate the hazard ratio (HR) for dementia. We recruited 12 068 patients with AF (6034 patients in each cohort). The mean follow-up time was 3.27 and 3.08 years in the groups using NOACs and warfarin, respectively. Compared with the HR for the group using warfarin, the HR for dementia was 0.82 (95% CI, 0.73-0.92; P=0.0004) in the group using NOACs. Subgroup analysis demonstrated that users of NOAC aged 65 to 74 years, with a high risk of stroke or bleeding were associated with a lower risk of dementia than users of warfarin with similar characteristics. Conclusions Patients with AF using NOACs were associated with a lower risk of dementia than those using warfarin. Further randomized clinical trials are greatly needed to prove these findings.

Prevention of Dementia in Patients with Atrial Fibrillation

Atrial fibrillation (AF) has been associated with an increased risk of dementia. Although there does not appear to be solid evidence that any specific treatment prevents or delays AF-associated cognitive decline, evidence is accumulating regarding the possible treatment strategies for preventing dementia. In this review, we summarize the evidence linking AF to dementia and critically appraise the proposed treatment strategies.

Atrial fibrillation (AF) is the most common form of arrhythmia in the elderly population and increases stroke risk by a factor of 4- to 5-fold. There is increasing evidence to suggest that incident AF may contribute to the development of dementia, independent of overt stroke. In particular, relatively younger patients with AF are more prone to dementia development than older patients with AF. Evidence is accumulating regarding the possible treatment strategies for preventing dementia in patients with AF. Oral anticoagulation may be effective for reducing the risk of dementia, even in patients with low stroke risks. Among oral anticoagulants, the use of non-vitamin K antagonists have been associated with a considerably decreased risk of dementia than warfarin. Moreover, successful catheter ablation for AF has also been associated with decreased dementia risk compared to medical therapy, suggesting that restoration of sinus rhythm, and not the ablation procedure itself, as the important mechanism in the prevention of AF-associated dementia. Among midlife patients with AF, there appeared to be a U-shaped association of blood pressure (BP) and a linear association of hypertension with dementia risk. A BP of 120 to 129/80 to 84 mmHg has been identified as the optimal range. Finally, integrated management of AF was associated with a reduced risk of dementia in AF patients.

Association of Risk of Dementia With Direct Oral Anticoagulants Versus Warfarin Use in Patients With Non-valvular Atrial Fibrillation: A Systematic Review and Meta-analysis

ABSTRACT

Atrial fibrillation (AF) is associated with an increased risk of dementia. Studies have shown the beneficial effects of anticoagulants in preventing dementia in this population. However, evidence around the use of direct oral anticoagulants (DOACs) versus warfarin in AF-related dementia prevention remains sparse. This systematic review and meta-analysis aimed to evaluate the use of DOACs versus warfarin in dementia prevention in this population. MEDLINE, EMBASE, PsycINFO, and the CENTRAL databases were systematically searched from its inception until May 2020. Nine studies (n = 611,069) were included for quantitative meta-analysis. DOACs use was associated with a lower risk of composite dementia outcomes compared with warfarin use [odds ratio (OR) 0.56, 95% confidence interval (CI) 0.34-0.94, P = 0.03]. No significant difference was found in subtypes of dementia (vascular dementia, Alzheimer's disease, and cognitive disorder) between both groups. No significant difference in the risk of composite dementia outcomes between the dabigatran and warfarin groups (OR 0.97, 95% CI 0.88-1.08, P = 0.61). Apixaban (OR 0.58, 95% CI 0.50-0.67, P < 0.00001) and rivaroxaban (OR 0.67, 95% CI 0.61-0.75, P < 0.00001) use were both associated with a significantly lower risk of composite dementia outcomes compared with warfarin use. Findings need to be interpreted with caution because of low certainty of evidence. In conclusion, this systematic review and meta-analysis of 9 comparative studies demonstrated the superiority of DOACs over warfarin in prevention of dementia in AF. Future prospective trials with adequate follow-up period are warranted to ascertain its causal relationship.

Factors influencing cognitive performance after 1-year treatment with direct oral anticoagulant in patients with atrial fibrillation and previous ischemic stroke: a pilot study

Anticoagulant treatment as stroke prevention, particularly direct oral anticoagulant (DOAC), may reduce the risk of dementia in patients with atrial fibrillation (AF). We aimed to assess factors influencing cognitive performance after 1-year treatment with DOAC in patients with AF and previous ischemic stroke. We recruited 33 ischemic stroke patients who were discharged from Verona Stroke Unit with diagnosis of AF and prescription of treatment with DOAC. For each cognitive test, we estimated the effect of T0 (first session) variables on T1 (1-year session) cognitive performance using ordinal logistic regression fitted to a 1 point-shift from 4 to 0 on ESs. The effect of T0 clinical variables was presented as odds ratio (OR) with 95% confidence interval (CI) after adjustment for T0 total score of the corresponding cognitive test. Sustained AF (OR: 4.259, 95% CI 1.071-16.942) and ischemic heart disease (OR: 6.654, 95% CI 1.329-33.300) showed a significant effect on T1 MoCA Test; congestive heart failure on T1 RAVLT Immediate recall (OR: 9.128, 95% CI 1.055-78.995), T1 RAVLT Delayed recall (OR: 7.134, 95% CI 1.214-52.760), and T1 Trail Making Test (Part A) (OR: 16.989, 95% CI 1.765-163.565); sustained AF (OR: 5.055, 95% CI 1.224-20.878) and hyperlipidemia (OR: 4.764, 95% CI 1.175-19.310) on T1 Digit span forward Test; ischemic heart disease (aOR: 8.460, 95% CI 1.364-52.471) on T1 Stroop Color and Word Test (time); Dabigatran use (aOR: 0.084, 95% CI 0.013-0.544) on FAB; age ≥ 75 years (aOR: 0.058, 95% CI 0.006-0.563) and hyperlipidemia (aOR: 5.809, 95% CI 1.059-31.870) on T1 Phonemic word fluency Test; female sex (aOR: 6.105, 95% CI 1.146-32.519), hyperlipidemia (aOR: 21.099, 95% CI 2.773-160.564), total Modified Fazekas Scale score > 1 (aOR: 78.530, 95% CI 3.131-1969.512) on Semantic word fluency Test. Sustained AF, ischemic heart disease, congestive heart failure, hyperlipidemia, and female sex were the factors influencing cognitive performance after 1-year treatment with DOAC in patients with AF and previous ischemic stroke. Modified Fazekas Scale score in the first session was the only radiological variable that had a significant effect on cognitive performance.

Thrombin, a Mediator of Coagulation, Inflammation, and Neurotoxicity at the Neurovascular Interface: Implications for Alzheimer's Disease

The societal burden of Alzheimer’s disease (AD) is staggering, with current estimates suggesting that 50 million people world-wide have AD. Identification of new therapeutic targets is a critical barrier to the development of disease-modifying therapies. A large body of data implicates vascular pathology and cardiovascular risk factors in the development of AD, indicating that there are likely shared pathological mediators. Inflammation plays a role in both cardiovascular disease and AD, and recent evidence has implicated elements of the coagulation system in the regulation of inflammation. In particular, the multifunctional serine protease thrombin has been found to act as a mediator of vascular dysfunction and inflammation in both the periphery and the central nervous system. In the periphery, thrombin contributes to the development of cardiovascular disease, including atherosclerosis and diabetes, by inducing endothelial dysfunction and related inflammation. In the brain, thrombin has been found to act on endothelial cells of the blood brain barrier, microglia, astrocytes, and neurons in a manner that promotes vascular dysfunction, inflammation, and neurodegeneration. Thrombin is elevated in the AD brain, and thrombin signaling has been linked to both tau and amyloid beta, pathological hallmarks of the disease. In AD mouse models, inhibiting thrombin preserves cognition and endothelial function and reduces neuroinflammation. Evidence linking atrial fibrillation with AD and dementia indicates that anticoagulant therapy may reduce the risk of dementia, with targeting thrombin shown to be particularly effective. It is time for “outside-the-box” thinking about how vascular risk factors, such as atherosclerosis and diabetes, as well as the coagulation and inflammatory pathways interact to promote increased AD risk. In this review, we present evidence that thrombin is a convergence point for AD risk factors and as such that thrombin-based therapeutics could target multiple points of AD pathology, including neurodegeneration, vascular activation, and neuroinflammation. The urgent need for disease-modifying drugs in AD demands new thinking about disease pathogenesis and an exploration of novel drug targets, we propose that thrombin inhibition is an innovative tactic in the therapeutic battle against this devastating disease.

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.

Association of Oral Anticoagulant Type With Risk of Dementia Among Patients With Nonvalvular Atrial Fibrillation

Background

Oral anticoagulants (OACs) in patients with atrial fibrillation (AF), in addition to reducing stroke risk, could also prevent adverse cognitive outcomes. The purpose of this study was to compare the risk of dementia incidence across patients with AF initiating different OACs.

Methods and Results

We identified patients with nonvalvular AF initiating OACs in 2 US healthcare claim databases, MarketScan (2007–2015) and Optum Clinformatics (2009–2015). Dementia, comorbidities, and use of medications were defined on the basis of inpatient and outpatient claims. We performed head‐to‐head comparisons of warfarin, dabigatran, rivaroxaban, and apixaban in propensity score–matched cohorts. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) of incident dementia for each propensity score–matched cohort and meta‐analyzed database‐specific results. We analyzed 307 099 patients with AF from the MarketScan database and 161 346 from the Optum database, of which 6572 and 4391, respectively, had a diagnosis of incident dementia. The mean follow‐up of each cohort ranged between 0.7 and 2.2 years. Patients initiating direct OACs experienced lower rates of dementia than those initiating warfarin (dabigatran: HR, 0.85; 95% CI, 0.71–1.01; rivaroxaban: HR, 0.85; 95% CI, 0.76–0.94; apixaban: HR, 0.80; 95% CI, 0.65–0.97). There were no differences in rates of dementia comparing direct OAC user groups (dabigatran versus rivaroxaban: HR, 1.02; 95% CI, 0.79–1.32; dabigatran versus apixaban: HR, 0.92; 95% CI, 0.63–1.36; apixaban versus rivaroxaban: HR, 1.01; 95% CI, 0.86–1.19).

Conclusions

Patients with AF initiating direct OACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular direct OAC in relation to dementia rates.

Nonvitamin K Antagonist Oral Anticoagulants Versus Warfarin in Atrial Fibrillation Patients and Risk of Dementia: A Nationwide Propensity-Weighted Cohort Study

Background It is unclear whether nonvitamin K antagonist oral anticoagulants ( NOAC s) can mitigate dementia development in atrial fibrillation. We compared dementia development among users of NOACs or warfarin in patients with atrial fibrillation with no prior neurological diagnoses. Methods and Results We conducted a Danish nationwide cohort study including 33 617 new oral anticoagulant users with nonvalvular atrial fibrillation, of which 11 052 were aged 60 to 69 years, 13 237 were aged 70 to 79 years, and 9238 were aged 80 years and older. To exclude prevalent non -oral anticoagulants- associated dementia, we considered the at-risk population of patients alive and free of dementia at 180 days following inclusion. We compared rates of new-onset dementia by age and treatment regimen using inverse probability of treatment weighting to account for confounding. Approximately 60% of patients were NOAC users and 40% were warfarin users. Mean follow-up was 3.4 years. Dementia occurred in 41 patients aged 60 to 69 years, 276 patients aged 70 to 79 years, and 441 patients aged 80 years and older. Relative to warfarin users, dementia rates were nonsignificantly lower among NOAC users aged 60 to 69 years (0.11 events/100 person-years versus 0.12 events/100 person-years; weighted hazard ratio, 0.92 [95% CI, 0.48-1.72]) and NOAC users aged 70 to 79 years (0.64 events/100 person-years versus 0.78 events/100 person-years; weighted hazard ratio , 0.86 [95% CI, 0.68-1.09]), whereas NOAC s were associated with significantly higher dementia rates (2.16 events/100 person-years versus 1.70 events/100 person-years; weighted hazard ratio , 1.31 [95% CI, 1.07-1.59]) in patients 80 years and older. Conclusions This nationwide cohort of patients with atrial fibrillation revealed no clinically meaningful difference in dementia development between users of NOACs or warfarin apart from a higher risk in NOAC users 80 years and older, which may relate to residual confounding from selective prescribing and unobserved comorbidities.