Age-dependency of prescribing patterns of oral anticoagulant drugs in Austria during 2011-2014

Drug interactions of direct oral anticoagulants in elderly patients with cardiometabolic diseases

In the present review we summarized current knowledge about significant interactions (DIs) of direct oral anticoagulants (DOACs) with other medications frequently prescribed to elderly patients with cardiometabolic diseases.

Literature search was performed using PubMed from 1990 to October 2020. Randomized clinical trials (RCTs), subgroup analyses from RCTs, longitudinal studies, case series and case reports were included. Only studies in humans were considered. Elderly was defined as ≥75 years.

Assessment of DIs with DOACs is often tricky because of the lack of validated tools to routinely assess magnitude of their anti-coagulation effect. Most of reports in the cardiometabolic area regarded the classes of anti-antiarrhythmic, lipid-lowering and platelet-inhibitors drugs, namely drugs that are widely used to reduce cardiovascular risk in patients with common metabolic diseases. Reports about elderly are limited in general, and it is not known whether certain types of DIs occur more frequently in elderly subjects. DIs were more frequently reported in association with dabigatran, which however has been available for a longer period of time compared with other DOACs. In most cases, no complete information about dosages of medications was available. DIs of DOACs leading to adverse events (both ischemic and bleeding ones) were generally facilitated by older age, polymedication and impaired renal function.

Further studies should be carried out to properly investigate DIs of DOACs with cardiometabolic drugs in elderly patients, with particular focus on differences between DOACs and the influence of different dosages.

Prescription patterns of direct oral anticoagulants and concomitant use of interacting medications in the Netherlands

Objectives

To describe the prevalence, temporal and regional trends in prescribing direct oral anticoagulants (DOACs) in conjunction with interacting medications.

Methods

We performed a cross-sectional study of pharmacy dispensing data in the Foundation for Pharmaceutical Statistics (SFK) registry on patients who have had a prescription for a DOAC filled at one of 831 randomly selected pharmacies in the Netherlands between Jan 2014–Jan 2019.

Results

We identified 99,211 patients who had a first DOAC prescription filled. Mean age was 71.6 ± 10.9 years, 58% were male. In 2014, 8,293 patients were treated with DOACs, in 2018, 35,415 were newly started on a DOAC. In 2018, the use of apixaban was most common (52%) in the Eastern region, whereas rivaroxaban was most frequently prescribed (32–48%) in the other regions. At time of first prescription, the vast majority (99.3%) used ≥ 1 concomitant interacting drug, and 3.2% used ≥ 3 interacting medications. Most common were digoxin (37.8%), atorvastatin (31.5%), verapamil (13.7%) and amiodarone (9.7%). While the number of interacting medications remained unchanged over time (median 1, interquartile range 1–1), there was a notable decrease in antiarrhythmic medications and an increase in non-cardiovascular interacting medications (e.g. dexamethasone from 0.9% to 7.1%, antiepileptic drugs from 2.5% to 3.8%, and haloperidol from 0.5% to 2.2% in 2014 and 2018, respectively).

Conclusion

DOAC use has quadrupled in Dutch clinical practice over the 5‑year period from 2014 to 2018. While the number of patients who take interacting medications remained stable, the profile of interacting medications has changed over time from cardiovascular to medications affecting other organ systems.

Supplementary Information

The online version of this article (10.1007/s12471-021-01612-4) contains supplementary material, which is available to authorized users.

Oral anticoagulant therapy and outcome in patients with stroke. A retrospective nation-wide cohort study in Austria 2012-2017

Purpose

Patients with stroke are at high risk of recurrence of vascular events. Non‐vitamin K oral anticoagulant (NOAC) and vitamin K antagonists (VKA) are used as secondary prophylaxis. The aim of this study was to evaluate the utilization of NOAC and VKA, and their impact on re‐stroke or death in Austria.

Methods

We analyzed retrospective data between 2012 and 2017 from medical services covered by the health insurance funds, which provides health care for all residents in Austria. Patients without anticoagulant medication 3 months preceding the index event were eligible.

Results

76 354 patients were discharged with a hospital diagnosis of stroke. From these, 16 436 patients with a median age of 78 years received VKA or NOAC. After adjustment, the recurrence of stroke was less frequent in patients with NOAC compared to those with VKA (HR 0.87; 95%CI 0.77–0.97). However, there was no difference in mortality rate after adjustment for age, sex, and co‐morbidities for patients with NOAC (HR 1.0; 95%CI 0.92–1.08). Diabetes (HR 1.25, 95%CI 1.08–1.45; HR 1.25, 95% CI 1.13–1.38) and cardiovascular disease (HR 1.43, 95%CI 1.24–1.65; HR 1.27, 95%CI 1.16–1.39) were significantly associated with re‐stroke or death. Younger age (p = 0.0028; HR 0.99, 95%CI 0.99–0.99) was significantly associated with re‐stroke, and advanced age (p < 0.0001; HR 1.09, 95%CI 1.08–1.09) with death.

Conclusion

NOAC prescription is related with a reduced risk of re‐stroke but increased mortality compared to patients with VKA. The event risk is associated with diabetes, cardiovascular disease and age.

Epidemiology of Venous Thromboembolism and Treatment Pattern of Oral Anticoagulation in Korea, 2009-2016: a Nationwide Study Based on the National Health Insurance Service Database

BACKGROUND

The annual incidence of venous thromboembolism (VTE) is increasing, and the treatment pattern of oral anticoagulants (OACs) has changed with introduction of new oral anticoagulants (NOACs). The aims of this study were to assess the annual incidence of VTE in a Korean population and the change of treatment pattern with availability of NOACs using a population-based database.

METHODS

Using the Korean National Health Insurance Services database, we identified patients diagnosed with VTE between 2009 and 2016. The annual prevalence of VTE and clinical characteristics and treatment pattern were investigated. The annual incidence of VTE was calculated using direct and indirect methods using the estimated Korean population in 2009 as the reference.

RESULTS

The annual incidence of VTE in Korean has increased yearly from 23.9 per 100,000 in 2009 to 42.2 in 2016. The overall rate of OAC prescription for VTE treatment increased from 55.9% to 68% in the same time period. The rate of initiation of NOAC treatment greatly increased, particularly from 2013 onwards, with a 20-fold increase from 2009 to 2016 (2.1% vs. 54.3%).

CONCLUSIONS

The annual incidence of VTE in Korea increased by almost two-fold from 2009 to 2016. The rate of initiation of NOAC treatment has increased substantially since 2013, and these agents have surpassed VKAs as the anticoagulant of choice for VTE. This temporal pattern of OAC prescription is consistent with the current clinical guidelines, which indicate NOACs over the warfarin in patients with VTE.

Individualised Risk Assessments for Recurrent Venous Thromboembolism: New Frontiers in the Era of Direct Oral Anticoagulants

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality and is associated with high recurrence rates. The introduction of direct oral anticoagulants (DOACs) in the 2010s has changed the landscape of VTE management. DOACs have become the preferred anticoagulant therapy for their ease of use, predictable pharmacokinetics, and improved safety profile. Increasingly, guidelines have recommended long term anticoagulation for some indications such as following first unprovoked major VTE, although an objective individualised risk assessment for VTE recurrence remains elusive. The balance of preventing VTE recurrence needs to be weighed against the not insignificant bleeding risk, which is cumulative with prolonged use. Hence, there is a need for an individualised, targeted approach for assessing the risk of VTE recurrence, especially in those patients in whom the balance between benefit and risk of long-term anticoagulation is not clear. Clinical factors alone do not provide the level of discrimination required on an individual level. Laboratory data from global coagulation assays and biomarkers may provide enhanced risk assessment ability and are an active area of research. A review of the prediction models and biomarkers for assessing VTE recurrence risk is provided, with an emphasis on contemporary developments in the era of DOACs and global coagulation assays.

Prevalence of Intracranial Injury in Adult Patients With Blunt Head Trauma With and Without Anticoagulant or Antiplatelet Use

STUDY OBJECTIVE

We determine the prevalence of significant intracranial injury among adults with blunt head trauma who are receiving preinjury anticoagulant or antiplatelet medications.

METHODS

This was a multicenter, prospective, observational study conducted from December 2007 to December 2015. Patients were enrolled in 3 emergency departments (EDs) in the United States. Adults with blunt head trauma who underwent neuroimaging in the ED were included. Use of preinjury aspirin, clopidogrel, and warfarin was recorded. Data on direct oral anticoagulants were not specifically recorded. The primary outcome was prevalence of significant intracranial injury on neuroimaging. The secondary outcome was receipt of neurosurgical intervention.

RESULTS

Among 9,070 patients enrolled in this study, the median age was 53.8 years (interquartile range 34.7 to 74.3 years) and 60.7% were men. A total of 1,323 patients (14.6%) were receiving antiplatelet medications or warfarin, including 635 receiving aspirin alone, 109 clopidogrel alone, and 406 warfarin alone. Compared with that of patients without any coagulopathy, the relative risk of significant intracranial injury was 1.29 (95% confidence interval [CI] 0.88 to 1.87) for patients receiving aspirin alone, 0.75 (95% CI 0.24 to 2.30) for those receiving clopidogrel alone, and 1.88 (95% CI 1.28 to 2.75) for those receiving warfarin alone. The relative risk of significant intracranial injury was 2.88 (95% CI 1.53 to 5.42) for patients receiving aspirin and clopidogrel in combination.

CONCLUSION

Patients receiving preinjury warfarin or a combination of aspirin and clopidogrel were at increased risk for significant intracranial injury, but not those receiving aspirin alone. Clinicians should have a low threshold for neuroimaging when evaluating patients receiving warfarin or a combination of aspirin and clopidogrel.

Barriers to continued administration of direct oral anticoagulants between acute hospital and subacute or chronic hospitals and geriatric health services facilities in Japan

Objectives: To investigate whether direct oral anticoagulant (DOAC) therapy at acute hospitals is continued after transfer to subacute or chronic hospitals and geriatric health services facilities in Japan.Methods: Acute hospitals routinely transfer patients to nearby subacute or chronic hospitals and geriatric health services facilities after acute stroke treatment. To elucidate the status of antithrombotic therapy, particularly DOAC therapy, we conducted a questionnaire survey of chief physicians at 33 subacute or chronic hospitals and geriatric health services facilities in the vicinity of Kawasaki City.Results: Responses were received from 23 hospitals and geriatric health services facilities (5 convalescent and rehabilitation hospitals, 5 chronic hospitals, 13 geriatric health services facilities). The number of convalescent hospitals responding, 'no problem with DOAC administration' before transfer to subacute or chronic hospitals and geriatric health services facilities increased from 4 (80%) at the introduction of DOACs to 5 (100%) presently. The number of chronic hospitals and geriatric health services facilities also increased from 1 (20%) to 3 (60%) and 4 (30.8%) to 5 (38.5%), respectively, albeit not significantly. The number of convalescent hospitals, chronic hospitals, and geriatric health services facilities requesting pre-transfer change of oral anticoagulants decreased from 20% to 0%, 60% to 40%, and 69.2% to 61.5%, respectively. All convalescent hospitals continued DOAC therapy after transfer. However, only 40.0% of chronic hospitals and 46.2% of geriatric health services facilities used DOACs in the present period. Warfarin was used instead at 3 (60%) chronic hospitals and 7 (53.8%) geriatric health services facilities and antiplatelet drugs were used at 1 hospital/facility each (20% and 7.7%, respectively). Nine (39.1%) hospitals and facilities cited high DOAC costs for the switch.Conclusions: Convalescent hospitals have incorporated DOAC use and readily accept patients receiving DOACs at transferring hospitals. Conversely, many chronic hospitals and geriatric health services facilities eventually switch from DOACs to warfarin or antiplatelet drugs due to cost. Efforts to resolve these barriers to continued administration of DOACs between acute hospitals and subacute or chronic hospitals and geriatric health services facilities in Japan are needed as soon as possible.

Appropriateness of initial dose of non-vitamin K antagonist oral anticoagulants in patients with non-valvular atrial fibrillation in the UK

OBJECTIVE

To evaluate the appropriateness of the initial prescribed daily dose of non-vitamin K antagonist oral anticoagulants (NOACs) according to label in patients with non-valvular atrial fibrillation (NVAF) in the UK.

DESIGN

Population-based cross-sectional study.

SETTING

UK primary care.

POPULATION

30 467 patients with NVAF and a first prescription for apixaban, dabigatran or rivaroxaban between January 2011 and December 2016.

MAIN OUTCOME MEASURES

Percentage of patients prescribed a NOAC dose according to the European Union (EU) labels (appropriately dosed), and not according to the EU labels (inappropriately dosed-including both underdosed and overdosed patients); percentage of patients prescribed an initial NOAC dose according to renal function status.

RESULTS

A total of 15 252 (50.1%) patients started NOAC therapy on rivaroxaban, 10 834 (35.6%) on apixaban and 4381 (14.4%) on dabigatran. Among patients starting NOAC therapy on rivaroxaban, 17.3% were eligible to receive a reduced dose compared with 12.8% of patients starting on apixaban and 53.8% of patients starting on dabigatran. The majority of patients were prescribed an appropriate dose according to the EU labels: apixaban 74.9 %, dabigatran, 74.4%; rivaroxaban, 84.2%. Underdosing occurred in 21.6% (apixaban), 8.7% (dabigatran), 9.1% (rivaroxaban). Overdosing was more frequent for dabigatran (16.9%) than for rivaroxaban (6.6%) or apixaban (3.5%). There was a trend towards dose reduction with increasing renal impairment. Among patients with severe renal impairment, the majority received a reduced dose NOAC: apixaban, 91.1%, dabigatran, 80.0%, rivaroxaban, 83.0%.

CONCLUSION

Between 2011 and 2016, the majority of patients starting NOAC therapy in UK primary care were prescribed a daily dose in line with the approved EU drug label. Underdosing was more than twice as common among patients starting on apixaban than those starting on dabigatran or rivaroxaban. Research into the patient characteristics that may influence inappropriate underdosing of NOACs in UK primary care is warranted.

Perioperative Management of Direct Oral Anticoagulants in Intracranial Surgery

The use of direct oral anticoagulants is increasing rapidly, because of perceived benefits over older agents, such as predictable pharmacokinetics and a reduced risk of bleeding. Elderly patients, who are more likely to be prescribed these drugs, are also presenting for neurosurgical procedures more often. The combination of these factors will result in neurosurgeons and neuroanesthesiologists encountering patients prescribed direct oral anticoagulants on an increasingly frequent basis. This review provides a summary of the current evidence pertaining to the perioperative management of these drugs, in the context of elective and emergency intracranial surgery. It highlights emerging therapies, including specific antidotes, as well as areas where the evidence base is likely to improve in the future.

Trends in the prescription of novel oral anticoagulants in UK primary care

AIMS

Novel oral anticoagulants (NOACs) are alternatives to vitamin-K antagonists (VKAs) for the prevention of thromboembolism. It is unclear how NOACs have been adopted in the UK since first introduced in 2008. The present study was conducted to describe the trends in the prescription of NOACs in the UK, including dabigatran, rivaroxaban and apixaban.

METHODS

Using the UK's Clinical Practice Research Datalink, the rates of new use of NOACs and VKAs from 2009 to 2015 were calculated using Poisson regression. Patient characteristics associated with NOAC initiation were identified using multivariate logistic regression.

RESULTS

The overall rate of oral anticoagulant initiation increased by 58% over the study period [rate ratio (RR) 1.58; 95% confidence interval (CI) 1.23, 2.03], even as the rate of new VKA use decreased by 31% (RR 0.69; 95% CI 0.52, 0.93). By contrast, the rate of initiation of NOAC increased, particularly from 2012 onwards, with a 17-fold increase from 2012 to 2015 (RR 17.68; 95% CI 12.16, 25.71). In 2015, NOACs accounted for 56.5% of oral anticoagulant prescriptions, with rivaroxaban prescribed most frequently, followed by apixaban and then dabigatran. Compared to VKAs, new NOAC users were less likely to have congestive heart failure, coronary artery disease and peripheral vascular disease, and more likely to have a history of ischaemic stroke.

CONCLUSIONS

In the UK, the rate of initiation of NOACs has increased substantially since 2009, and these agents have now surpassed VKAs as the anticoagulant of choice. Moreover, the characteristics of patients initiated on NOACs have changed over time, and this should be accounted for in future studies comparing NOACs and VKAs.