Anticoagulation Therapy for Atrial Fibrillation in Patients With Alzheimer's Disease

Methods for Economic Evaluations of Novel Oral Anticoagulants in Patients with Atrial Fibrillation: A Systematic Review

BACKGROUND

Atrial fibrillation (AF) is a severe epidemiological and public health concern among the elderly population worldwide, with substantial economic and social burdens. Economic evaluations can play an essential role in optimizing the utilization of scarce resources. In recent years, the number of economic evaluation studies related to AF has increased due to the rising number of AF patients, the continuous updating of clinical data, and the emergence of real-world evidence. However, there are still deficiencies in model settings and parameter sources in relevant studies.

OBJECTIVE

This study aims to review the existing economic evaluations of novel oral anticoagulants (NOACs) in patients with AF and summarize the evidence and methods applied.

METHODS

A comprehensive and systematic search was conducted on electronic databases, including PubMed, Embase, Web of Science (WOS), and The Cochrane Library, from the date of database creation to November 2022. The reporting quality of included literature was assessed using the Consolidated Health Economic Evaluation Reporting Standards 2022 (CHEERS 2022) statement.

RESULTS

A total of 102 studies were included in the review, with 200 comparisons between NOACs and vitamin K antagonists (VKAs), as well as 58 comparisons between different NOACs. The healthcare sector and payer perspectives were the most common, and accordingly, the majority of the evaluations considered only direct medical costs. Most studies used Markov cohort models with the number of health states ranging from 4 to 29. Of included studies, 80 (78%) considered event recurrence and complications, and 78 (76%) considered discontinuation and second-line therapy. All of the studies applied uncertainty analysis to explore the robustness of the results. Of all 200 NOACs-VKAs comparisons, 149 (75%) showed that NOACs were more cost-effective; this proportion was 84% (139 out of 165) in high-income countries but decreased to 29% (10 out of 35) in middle- and low-income countries. Most (82%) of the 28 items in the CHEERS 2022 checklist were elucidated in the majority of included studies. A minority (only 39%) of included studies demonstrated high reporting quality.

CONCLUSION

NOACs may be more cost-effective than VKAs in patients with AF, but this conclusion applies to high-income countries, whereas VKAs may be more cost-effective in middle- and low-income countries. The reporting quality of included studies was variable, and certain methodological issues were presented. This study highlights the economic evaluation methodology of NOACs in patients with AF and provides recommendations for modeling methods and future studies.

Clinical benefits of oral anticoagulants in atrial fibrillation patients with dementia: a systematic review and meta-analysis

Background

The management of atrial fibrillation (AF) with oral anticoagulants (OAC) is generally recommended to reduce the risk of stroke. However, the decision to prescribe these medications for patients with AF and dementia remains controversial.

Methods

A systematic review and meta-analysis of retrospective cohort studies were conducted. The search encompassed PubMed, Cochrane Library, Web of Science, and Embase databases from inception until May 1st, 2023, with language limited to English. Eligible studies included comparisons between exposure to OAC vs. non-OAC in the AF population with dementia or cognitive impairment. Studies that compared the effects of direct oral anticoagulants (DOAC) and vitamin-K antagonists were also included. The primary outcome was all-cause mortality, and the secondary outcomes were ischemic stroke and major bleeding. This study was registered with PROSPERO (No. CRD42023420678).

Results

A total of five studies (N = 21,962 patients) met the eligibility criteria and were included in this review. The follow-up duration ranged from 1 to 4 years. Meta-analysis demonstrated that OAC treatment was associated with a lower risk of all-cause mortality in AF patients with dementia with a hazard ratio (HR) of 0.79 and a 95% confidence interval (CI) ranging from 0.68 to 0.92, compared to non-OAC treatment. No statistical differences were observed in the risk of major bleeding (HR = 1.12, 95% CI: 0.88-1.42) or ischemic stroke (HR = 0.77, 95% CI: 0.58-1.00). Three studies reported comparisons between DOAC and warfarin; however, pooled analysis was not performed due to heterogeneity.

Conclusion

The use of OACs in individuals diagnosed with both AF and dementia holds the potential to reduce all-cause mortality rates, thereby improving the overall clinical prognosis within this specific population.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023420678, PROSPERO identifier, CRD42023420678.

Cost Effectiveness of Strategies to Manage Atrial Fibrillation in Middle- and High-Income Countries: A Systematic Review

BACKGROUND

Atrial fibrillation (AF) remains the most common form of cardiac arrhythmia. Management of AF aims to reduce the risk of stroke, heart failure and premature mortality via rate or rhythm control. This study aimed to review the literature on the cost effectiveness of treatment strategies to manage AF among adults living in low-, middle- and high-income countries.

METHODS

We searched MEDLINE (OvidSp), Embase, Web of Science, Cochrane Library, EconLit and Google Scholar for relevant studies between September 2022 and November 2022. The search strategy involved medical subject headings or related text words. Data management and selection was performed using EndNote library. The titles and abstracts were screened followed by eligibility assessment of full texts. Selection, assessment of the risk of bias within the studies, and data extraction were conducted by two independent reviewers. The cost-effectiveness results were synthesised narratively. The analysis was performed using Microsoft Excel 365. The incremental cost effectiveness ratio for each study was adjusted to 2021 USD values.

RESULTS

Fifty studies were included in the analysis after selection and risk of bias assessment. In high-income countries, apixaban was predominantly cost effective for stroke prevention in patients at low and moderate risk of stroke, while left atrial appendage closure (LAAC) was cost effective in patients at high risk of stroke. Propranolol was the cost-effective choice for rate control, while catheter ablation and the convergent procedure were cost-effective strategies in patients with paroxysmal and persistent AF, respectively. Among the anti-arrhythmic drugs, sotalol was the cost-effective strategy for rhythm control. In middle-income countries, apixaban was the cost-effective choice for stroke prevention in patients at low and moderate risk of stroke while high-dose edoxaban was cost effective in patients at high risk of stroke. Radiofrequency catheter ablation was the cost-effective option in rhythm control. No data were available for low-income countries.

CONCLUSION

This systematic review has shown that there are several cost-effective strategies to manage AF in different resource settings. However, the decision to use any strategy should be guided by objective clinical and economic evidence supported by sound clinical judgement.

REGISTRATION

CRD42022360590.

Prevalence of oral anticoagulant use among people with and without Alzheimer’s disease

Background

Although cardio- and cerebrovascular diseases are common among people with Alzheimer’s disease (AD), it is unknown how the prevalence of oral anticoagulant (OAC) use changes in relation to AD diagnosis. We investigated the prevalence of OAC use in relation to AD diagnosis in comparison to a matched cohort without AD.

Methods

Register-based Medication use and Alzheimer’s disease (MEDALZ) cohort includes 70 718 Finnish people with AD diagnosed between 2005–2011. Point prevalence of OAC use (prescription register) was calculated every three months with three-month evaluation periods, from five years before to five years after clinically verified diagnosis and compared to matched cohort without AD. Longitudinal association between AD and OAC use was evaluated by generalized estimating equations (GEE).

Results

OAC use was more common among people with AD until AD diagnosis, (OR 1.17; 95% CI 1.13–1.22), and less common after AD diagnosis (OR 0.87; 95% CI 0.85–0.89), compared to people without AD. At the time of AD diagnosis, prevalence was 23% and 20% among people with and without AD, respectively. OAC use among people with AD began to decline gradually two years after AD diagnosis while continuous increase was observed in the comparison cohort. Warfarin was the most common OAC, and atrial fibrillation was the most common comorbidity in OAC users.

Conclusion

Decline in OAC use among people with AD after diagnosis may be attributed to high risk of falling and problems in monitoring. However, direct oral anticoagulants (DOACs) that are nowadays more commonly used require less monitoring and may also be safer for vulnerable people with AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03144-x.

Management of Atrial Fibrillation in Patients 75 Years and Older: JACC State-of-the-Art Review

The prevalence of atrial fibrillation (AF) is increasing as the population ages. AF treatment-related complications also increase markedly in older adults (defined as ≥75 years of age for this review). The older AF population has a high risk of stroke, bleeding, and death. Syncope and fall-related injuries are the most common reasons for nonprescription of oral anticoagulation (OAC), and are more common in older adults when OACs are used with antiarrhythmic drugs. Digoxin may be useful for rate control, but associations with increased mortality limit its use. Beyond rate and rhythm control considerations, stroke prophylaxis is critical to AF management, and the benefits of direct OACs, compared with warfarin, extend to older adults. Invasive procedures such as AF catheter ablation, pacemaker implantation/atrioventricular junction ablation, and left atrial appendage occlusion may be useful in appropriately selected cases. However, older adults have generally been under-represented in clinical trials.

Predicting the Potency of Anti-Alzheimer’s Drug Combinations Using Machine Learning

Clinical trials of single drugs intended to slow the progression of Alzheimer’s Disease (AD) have been notoriously unsuccessful. Combinations of repurposed drugs could provide effective treatments for AD. The challenge is to identify potentially effective combinations. To meet this challenge, machine learning (ML) was used to extract the knowledge from two leading AD databases, and then “the machine” predicted which combinations of the drugs in common between the two databases would be the most effective as treatments for AD. Specifically, three-layered artificial neural networks (ANNs) with compound, gated units in their internal layer were trained using ML to predict the cognitive scores of participants, separately in either database, given other data fields including age, demographic variables, comorbidities, and drugs taken. The predictions from the separately trained ANNs were statistically highly significantly correlated. The best drug combinations, jointly determined from both sets of predictions, were high in nonsteroidal anti-inflammatory drugs; anticoagulant, lipid-lowering, and antihypertensive drugs; and female hormones. The results suggest that the neurodegenerative processes that underlie AD and other dementias could be effectively treated using a combination of repurposed drugs. Predicted drug combinations could be evaluated in clinical trials.