Trends and Predictors of Oral Anticoagulant Use in People with Alzheimer’s Disease and the General Population in Australia

Is It Safe to Resume Direct Oral Anticoagulants upon Discharge after Hip Fracture Surgery? A Retrospective Study

This study aimed to examine the incidence rate of early reoperations following hip fracture surgery and determine the safety of resuming direct oral anticoagulants. Many orthopedic surgeons are reluctant to resume chronic anticoagulation therapy for patients after surgical intervention for hip fractures. One of the main reasons is the potential for reoperation in the case of surgical complications. We conducted a retrospective cohort study at an Academic Level I trauma center, reviewing the records of 425 geriatric patients (age > 60) who underwent hip fracture surgery between 2018 and 2020, including a subgroup treated with direct oral anticoagulants prior to hospitalization. The study assessed the incidence rate of complications requiring early reoperation. Out of the 425 patients, only nine (2%) required reoperation within a month after discharge, with two (0.5%) on chronic anticoagulation therapy. None of the reoperations were urgent, and all were performed at least 24 h after re-admission. The findings revealed a very low incidence rate of reoperations in patients who underwent hip fracture surgery, with no reoperations performed within 24 h of re-admission. Consequently, we believe that resuming chronic direct oral anticoagulants is a safe and effective approach when discharging patients after hip fracture surgery.

Validity of three risk prediction models for dementia or cognitive impairment in Australia

BACKGROUND

no studies have compared the predictive validity of different dementia risk prediction models in Australia.

OBJECTIVES

(i) to investigate the predictive validity of the Australian National University-Alzheimer's Disease Risk Index (ANU-ADRI), LIfestyle for BRAin Health (LIBRA) Index and cardiovascular risk factors, ageing and dementia study (CAIDE) models for predicting probable dementia/cognitive impairment in an Australian cohort. (ii) To develop and assess the predictive validity of a new hybrid model combining variables from the three models.

METHODS

the Hunter Community Study (HCS) included 3,306 adults aged 55-85 years with a median follow-up of 7.1 years. Probable dementia/cognitive impairment was defined using Admitted Patient Data Collection, dispensing of cholinesterase inhibitors or memantine, or a cognitive test. Model validity was assessed by calibration and discrimination. A hybrid model was developed using deep neural network analysis, a machine learning method.

RESULTS

120 (3.6%) participants developed probable dementia/cognitive impairment. Mean calibration by ANU-ADRI, LIBRA, CAIDE and the hybrid model was 19, 0.5, 4.7 and 3.4%, respectively. The discrimination of the models was 0.65 (95% CI 0.60-0.70), 0.65 (95% CI 0.60-0.71), 0.54 (95% CI 0.49-0.58) and 0.80 (95% CI 0.78-0.83), respectively.

CONCLUSION

ANU-ADRI and LIBRA were better dementia prediction tools than CAIDE for identification of high-risk individuals in this cohort. ANU-ADRI overestimated and LIBRA underestimated the risk. The new hybrid model had a higher predictive performance than the other models but it needs to be validated independently in longitudinal studies.

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.

Factor XI Inhibitors for Prevention and Treatment of Venous Thromboembolism: A Review on the Rationale and Update on Current Evidence

Although anticoagulation therapy has evolved from non-specific drugs (i.e., heparins and vitamin K antagonists) to agents that directly target specific coagulation factors (i.e., direct oral anticoagulants, argatroban, fondaparinux), thrombosis remains a leading cause of death worldwide. Direct oral anticoagulants (i.e., factor IIa- and factor Xa-inhibitors) now dominate clinical practice because of their favorable pharmacological profile and ease of use, particularly in venous thromboembolism (VTE) treatment and stroke prevention in atrial fibrillation. However, despite having a better safety profile than vitamin K antagonists, their bleeding risk is not insignificant. This is true for all currently available anticoagulants, and a high bleeding risk is considered a contraindication to anticoagulation. As a result, ongoing research focuses on developing future anticoagulants with an improved safety profile. Several promising approaches to reduce the bleeding risk involve targeting the intrinsic (or contact activation) pathway of coagulation, with the ultimate goal of preventing thrombosis without impairing hemostasis. Based on epidemiological data on hereditary factor deficiencies and preclinical studies factor XI (FXI) emerged as the most promising candidate target. In this review, we highlight unmet clinical needs of anticoagulation therapy, outlay the rationale and evidence for inhibiting FXI, discuss FXI inhibitors in current clinical trials, conduct an exploratory meta-analysis on their efficacy and safety, and provide an outlook on the potential clinical application of these novel anticoagulants.

Changing paradigms: from prevention of thromboembolic events to improved survival in patients with atrial fibrillation

Atrial fibrillation is associated with a five-fold increase in the risk of stroke. Current guidelines recommend the use of the CHA2DS2-VASc score to stratify the risk of stroke. In addition, guidelines recommend the identification of the conditions that increase the risk of haemorrhage to be modified and thus decrease the risk of bleeding. Nevertheless, many patients with a high thromboembolic risk are prescribed antiplatelet treatment or do not receive any antithrombotic therapy. In addition, therapeutic inertia is common in anticoagulated patients taking vitamin K antagonists, and underdosing is an emerging problem with direct oral anticoagulants, probably because many physicians consider the risk of stroke and the risk of major bleeding to be equal. It is necessary to develop a new approach to risk stratification, an approach that moves from morbidity to mortality, i.e., from stratification of the risk of stroke and major bleeding to stratification of the risk of mortality associated with stroke and the risk of mortality associated with bleeding. In this article, we propose a novel risk stratification approach based on the mortality associated with stroke and bleeding, illustrated by data derived from the literature.

Patterns and factors influencing oral anticoagulant prescription in people with atrial fibrillation and dementia: Results from UK primary care

AIMS

Oral anticoagulant (OAC) is recommended for preventing stroke in atrial fibrillation (AF). However, the OAC utilisation in AF patients with dementia or cognitive impairment (CI) is limited. This study aimed to examine the prevalence of OAC prescriptions in AF patients with dementia/CI and to identify factors associated with OAC treatment within 180 days after dementia/CI diagnosis.

METHODS

Using The Health Improvement Network database, the annual trends of OAC between 2000 and 2015 were calculated. Multivariable logistic regression was performed to identify factors associated with OAC treatment.

RESULTS

The prevalence rate of OAC prescriptions increased from 6.1% in 2000 to 45.9% in 2015. Among OAC users, the proportion of direct oral anticoagulants (DOACs) use increased significantly from 0.1% in 2011 to 33.8% in 2015 (P-trend < 0.001), while the proportion of vitamin K antagonist use decreased by 28.6% from 100% in 2000 to 71.4% in 2015 (P-trend < 0.001). In the multivariable analysis, younger age, very old age, female sex, higher Charlson Comorbidity Index, having a HAS-BLED score ≥3, a history of intracranial bleeding, falls and polypharmacy were significantly associated with lower odds of receiving OAC.

CONCLUSIONS

In UK primary care, OAC use increased from 2000 to 2015 in AF patients with dementia/CI, with a substantial increase in use of DOACs. Characteristics related to frailty are associated with lower odds of OAC prescription. Given the increasing use of DOACs in patients with dementia/CI, further studies are needed to investigate the safety and effectiveness of DOACs in this important patient group.

Using clinical registries, administrative data and electronic medical records to improve medication safety and effectiveness in dementia

PURPOSE OF REVIEW

Clinical registries, routinely collected administrative data and electronic medical records (EMRs) provide new opportunities to investigate medication safety and effectiveness. This review outlines the strengths and limitations of these data, and highlights recent research related to safe and effective medication use in dementia.

RECENT FINDINGS

Clinical registries, administrative data and EMRs facilitate observational research among people often excluded from randomized controlled trials (RCTs). Larger sample sizes and longer follow-up times permit research into less common adverse events not apparent in RCTs. The validity of diagnoses recorded in administrative data and EMRs remains variable, although positive predictive values are typically high and sensitivity is low. Dispensing records are a rich source of data for estimating medication exposure. Recent research has investigated medications and prescribing patterns as risk factors for incident dementia, strategies to alleviate behavioural symptoms and the management of comorbidity. Common study protocols and common data models are examples of distributed network approaches increasingly used to conduct large and generalizable multi-database studies across different countries.

SUMMARY

Greater availability of electronic health data provides important opportunities to address evidence-practice gaps in relation to medication use and safety in people with dementia.

Application of Healthcare 'Big Data' in CNS Drug Research: The Example of the Neurological and mental health Global Epidemiology Network (NeuroGEN)

Neurological and psychiatric (mental health) disorders have a large impact on health burden globally. Cognitive disorders (including dementia) and stroke are leading causes of disability. Mental health disorders, including depression, contribute up to one-third of total years lived with disability. The Neurological and mental health Global Epidemiology Network (NeuroGEN) is an international multi-database network that harnesses administrative and electronic medical records from Australia, Asia, Europe and North America. Using these databases NeuroGEN will investigate medication use and health outcomes in neurological and mental health disorders. A key objective of NeuroGEN is to facilitate high-quality observational studies to address evidence-practice gaps where randomized controlled trials do not provide sufficient information on medication benefits and risks that is specific to vulnerable population groups. International multi-database research facilitates comparisons across geographical areas and jurisdictions, increases statistical power to investigate small subpopulations or rare outcomes, permits early post-approval assessment of safety and effectiveness, and increases generalisability of results. Through bringing together international researchers in pharmacoepidemiology, NeuroGEN has the potential to be paradigm-changing for observational research to inform evidence-based prescribing. The first focus of NeuroGEN will be to address evidence-gaps in the treatment of chronic comorbidities in people with dementia.