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

Factors associated with cognitive impairment in patients with atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is associated with an increased risk of cognitive impairment. Therefore, exploring factors which may be associated with cognitive impairment is important. Correspondingly, this study aimed to systematically evaluate factors associated with cognitive impairment in AF patients by synthesizing relevant evidence.

METHODS

A database search of the PubMed, Embase, Cochrane Library, Web of Science, CBM, CNKI, Wanfang, and VIP databases was conducted from inception until December 21, 2023. The effect size was expressed as a combined odds ratio (OR) and 95 % confidence interval (95 % CI). The heterogeneity was qualitatively analyzed by Cochran's Q test and quantified by the I2 statistic.

RESULTS

A total of 7,128 studies were identified from the 8 databases, and 39 studies of 3,491,423 participants were included. A meta-analysis was performed on 19 influencing factors. Advanced age (OR=1.38, 95 % CI: 1.11-1.71), female sex (OR=2.19, 95 % CI: 1.18-4.06), smoking (OR=2.44, 95 % CI: 1.24-4.80), hypertension (OR=1.61, 95 % CI: 1.27-2.03), diabetes (OR=1.42, 95 % CI: 1.20-1.67), and hearing impairment (OR=1.37, 95 % CI: 1.05-1.81) were risk factors for cognitive impairment. A higher education level (OR=0.57, 95 % CI: 0.46-0.72), oral anticoagulants (OR=0.61, 95 % CI: 0.48-0.78), novel oral anticoagulants (OR=0.63, 95 % CI: 0.54-0.73), warfarin (OR=0.55, 95 % CI: 0.39-0.79), novel oral anticoagulants relative to warfarin (OR=0.88, 95 % CI: 0.81-0.97), catheter ablation (OR=0.74, 95 % CI: 0.58-0.94) and exercise (OR=0.66, 95 % CI: 0.61-0.72) were protective factors for cognitive impairment.

CONCLUSIONS

Age, sex, education level, smoking, exercise, hypertension, diabetes, hearing impairment, anticoagulation therapy, and catheter ablation were associated with cognitive impairment in AF patients.

Clinical Correlates and Prognostic Impact of Cognitive Dysfunction in Patients With Heart Failure and Preserved Ejection Fraction: Insights From PARAGON-HF

BACKGROUND

Cognitive impairment is common in patients with heart failure and preserved ejection fraction but its clinical correlates and prognostic associations are poorly understood.

METHODS

We analyzed cognitive function, using the Mini-Mental State Examination (MMSE), in patients with heart failure and preserved ejection fraction enrolled in a prespecified substudy of the PARAGON-HF trial (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Global Outcomes in Heart Failure With Preserved Ejection Fraction). Logistic regression analyses were performed to determine the variables associated with lower MMSE scores at baseline and postbaseline decline in MMSE scores at 48 weeks. Cox proportional hazards regression and semiparametric proportional rates models were used to examine the risk of clinical outcomes related to baseline MMSE scores, and decline in MMSE scores during follow-up, adjusted for prognostic variables including NT-proBNP (N-terminal pro-B-type natriuretic peptide).

RESULTS

At baseline, cognitive function was normal (MMSE score 28-30) in 1809 of 2895 patients (62.5%), borderline (score 24-27) in 794 (27.4%), and impaired (score <24) in 292 (10.1%). Variables associated with both a lower MMSE score at baseline and a decline in score from baseline included older age, a history of stroke or transient ischemic attack, and lower serum albumin. Compared with those with baseline MMSE scores of 28 to 30, patients in the lower MMSE score categories had a stepwise increase in the risk of the composite of time to first heart failure hospitalization or cardiovascular death, with an adjusted hazard ratio of 1.27 (95% CI, 1.06-1.53) for those with scores of 24 to 27 and 1.58 (95% CI, 1.21-2.06) for those with scores <24, respectively. These associations were also found for the individual components of the composite and all-cause death. Likewise, cognitive impairment was associated with a 50% higher risk of total (first and repeat) heart failure hospitalizations and cardiovascular deaths. Examining the change in MMSE score from baseline, a decrease in MMSE score during follow-up was associated with a higher risk of death.

CONCLUSIONS

In patients with heart failure and preserved ejection fraction, even modest baseline impairment of cognitive function was associated with worse outcomes, including death. A decline in MMSE score during follow-up was a strong predictor of mortality, independent of other prognostic variables.

Vascular cognitive impairment and dementia: Mechanisms, treatment, and future directions

Worldwide, around 50 million people live with dementia, and this number is projected to triple by 2050. It has been estimated that 20% of all dementia cases have a predominant cerebrovascular pathology, while perhaps another 20% of vascular diseases contribute to a mixed dementia picture. Therefore, the vascular contribution to dementia affects 20 million people currently and will increase markedly in the next few decades, particularly in lower- and middle-income countries.In this review, we discuss the mechanisms of vascular cognitive impairment (VCI) and review management. VCI refers to the spectrum of cerebrovascular pathologies that contribute to any degree of cognitive impairment, ranging from subjective cognitive decline, to mild cognitive impairment, to dementia. While acute cognitive decline occurring soon after a stroke is the most recognized form of VCI, chronic cerebrovascular disease, in particular cerebral small-vessel disease, can cause insidious cognitive decline in the absence of stroke. Moreover, cerebrovascular disease not only commonly co-occurs with Alzheimer's disease (AD) and increases the probability that AD pathology will result in clinical dementia, but may also contribute etiologically to the development of AD pathologies.Despite its enormous health and economic impact, VCI has been a neglected research area, with few adequately powered trials of therapies, resulting in few proven treatments. Current management of VCI emphasizes prevention and treatment of stroke and vascular risk factors, with most evidence for intensive hypertension control. Reperfusion therapies in acute stroke may attenuate the risk of VCI. Associated behavioral symptoms such as apathy and poststroke emotionalism are common. We also highlight novel treatment strategies that will hopefully lead to new disease course-modifying therapies. Finally, we highlight the importance of including cognitive endpoints in large cardiovascular prevention trials and the need for an increased research focus and funding for this important area.

Clinical profile and outcomes in very elderly patients with atrial fibrillation anticoagulated with rivaroxaban: data from the EMIR study

Objectives

To analyze the clinical profile, adequacy of treatment with rivaroxaban and outcomes in octogenarians with atrial fibrillation (AF), taking rivaroxaban in clinical practice.

Methods

Observational and non-interventional study that included AF adults recruited from 79 Spanish centers, anticoagulated with rivaroxaban ≥ 6 months before being included. Data were analyzed according to age (≥ 80 vs. < 80 years) at baseline.

Results

Out of 1433 patients, 453 (31.6%) were octogenarians at baseline. Compared to younger patients, octogenarians had more comorbidities, higher CHA2DS2-VASc (4.5 ± 1.3 vs. 3.0 ± 1.4; P < 0.001) and HAS-BLED scores (2.0 ± 1.0 vs. 1.4 ± 1.0; P < 0.001). Overall, the dose of rivaroxaban was adequately prescribed in 83.4% of patients, but more frequently in the younger population (71.1% vs. 89.1%; P = 0.039). After a mean follow-up of 2.2 ± 0.6 years, annual rates of stroke + systemic embolism + transient ischemic attack, MACE, cardiovascular death and major bleeding were 1.03%, 1.24%, 1.03% and 1.75%, respectively, in octogenarian patients. Except for progressive heart failure death and major bleeding, rates of outcomes in octogenarians were similar compared to younger patients. In octogenarians, the concomitant use of antiplatelet agents and non-severe dementia were independently associated with the development of ischemic stroke, whereas previous coronary revascularization and heart failure with MACE, and higher HAS-BLED score with major bleeding.

Conclusions

In clinical practice, around one third of patients taking rivaroxaban are octogenarians. These patients have many comorbidities and a high thromboembolic risk. Despite that, rates of adverse events remain low. Rivaroxaban is adequately prescribed in the majority of octogenarians.

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 anticoagulant therapy in older adults

Patients aged ≥65 years not only account for the majority of patients with atrial fibrillation (AF) and venous thromboembolism (VTE), they are also at a higher risk of morbidity, mortality, and undertreatment than younger patients. Several age-related physiological changes with effects on drug pharmacokinetics/-dynamics and blood vessel fragility as well as the higher prevalence of geriatric conditions such as frailty, multimorbidity, polypharmacy, fall risk, dementia, and malnutrition make older persons more vulnerable to disease- and anticoagulation-related complications. Moreover, because older patients with AF/VTE are underrepresented in oral anticoagulation (OAC) trials, evidence on OAC in older adults with AF/VTE is mainly based on subgroup analyses from clinical trials and observational studies. A growing body of such limited evidence suggests that direct oral anticoagulants (DOACs) may be superior in terms of efficacy and safety compared to vitamin K antagonists in older persons with AF/VTE and that specific DOACs may have a differing risk-benefit profile. In this narrative review, we summarize the evidence on epidemiology of AF/VTE, impact of age-related physiological changes, efficacy/safety of OAC, specifically considering individuals with common geriatric conditions, and review OAC guideline recommendations for older adults with AF/VTE. We also propose a research agenda to improve the evidence basis on OAC older individuals with AF/VTE, including the conduct of advanced age-specific and pragmatic studies using less restrictive eligibility criteria and patient-reported health outcomes, in order to compare the effectiveness and safety of different DOACs, and investigate lower-dose regimens and optimal OAC durations in older patients.

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.

Disease latency and new-user versus prevalent-user cohort designs: Implications for pharmacoepidemiology in dementia

See the Reply by Lee et al. in this issue.

Diagnosis and Management of Atrial Fibrillation in Acute Ischemic Stroke in the Setting of Reperfusion Therapy: Insights and Strategies for Optimized Care

Reperfusion therapy in the form of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) has revolutionised the field of stroke medicine. Atrial fibrillation (AF) patients constitute a major portion of the overall stroke population; however, the prevalence of AF amongst acute ischemic stroke (AIS) patients receiving reperfusion therapy remains unclear. Limitations in our understanding of prevalence in this group of patients are exacerbated by difficulties in appropriately diagnosing AF. Additionally, the benefits of reperfusion therapy are not consistent across all subgroups of AIS patients. More specifically, AIS patients with AF often tend to have poor prognoses despite treatment relative to those without AF. This article aims to present an overview of the diagnostic and therapeutic management of AF and how it mediates outcomes following stroke, most specifically in AIS patients treated with reperfusion therapy. We provide unique insights into AF prevalence and outcomes that could allow healthcare professionals to optimise the treatment and prognosis for AIS patients with AF. Specific indications on acute neurovascular management and secondary stroke prevention in AIS patients with AF are also discussed.