Adherence to anticoagulant treatment with dabigatran in a real-world setting

Adherence, persistence and switching rates of apixaban, dabigatran and rivaroxaban in non-valvular atrial fibrillation: a multicentre real-life analysis at 3 years

INTRODUCTION

Adherence to and persistence with long-term treatment with oral anticoagulants play a significant role in preventing adverse events and mortality in patients with cardiac conditions. The aim of this study was to evaluate the adherence, persistence and switching rate at 3 years in real-life patients with non-valvular atrial fibrillation receiving treatment with first-line new oral anticoagulants.

METHODS

The study assessed all patients treated with drugs with the ATC codes B01AA, B01AE, B01AF and dispensed in pharmacies in the Lanciano-Vasto-Chieti and Pescara Local Health Units from 1 January 2011 to 30 September 2021. Adherence was calculated as the proportion of days covered; persistence was calculated as the difference in days between the start and end of treatment; and the switching rate was calculated as the difference in days between the start of treatment and the switch.

RESULTS

A total of 4270 patients were analysed. The absolute adherence figure at 3 years was 0.85. The lowest adherence levels were found in patients treated with dabigatran with an absolute value of 0.72, while the highest levels were found in patients treated with rivaroxaban with an absolute value at 3 years of 0.88. The persistence curves at 3 years of treatment with dabigatran showed a statistically significant difference (p<0.0001) compared with those of rivaroxaban and apixaban.

CONCLUSIONS

The data collected over a 3-year period showed that adherence and persistence levels and switch data were optimal and comparable in patients with non-valvular atrial fibrillation receiving treatment with either rivaroxaban or apixaban. In contrast, patients treated with dabigatran had worrying adherence and persistence levels.

"I just didn't want to trust it at all": Atrial fibrillation patient's treatment experience of rivaroxaban and warfarin

BACKGROUND

In the treatment of atrial fibrillation (AF), anticoagulant medications such as warfarin and rivaroxaban are commonly prescribed to reduce the risk of ischaemic strokes, and other thromboembolic events. Research has highlighted advantages and disadvantages of each of these medications, but there remains an absence of qualitative evidence regarding the lived experiences of AF patients. The present study helps address this gap and obtain a greater understanding of the patient experience and beliefs surrounding their anticoagulant medication.

METHOD

Semi-structured qualitative interviews with a purposive sample of 20 participants (10 warfarin, 10 rivaroxaban). Interviews were transcribed verbatim and thematically analysed.

RESULTS

Data analysis led to the generation of three key themes: positive perceptions of medication, distrust of alternatives, and inconsistencies in support experiences.

CONCLUSIONS

Positive perceptions of one anticoagulant medication (ACM) and distrust of alternatives may influence patients' confidence in switching medications. This is potentially problematic where there is a lack of patient engagement in medication changes, as seen during the COVID pandemic. Gaps in patient understanding of anticoagulation, including lack of clarity around medications selection and misconceptions about treatment, were evident. By addressing these misconceptions, clinicians may be better positioned to support people with AF in self-management of their ACM.

Prospective evaluation of the effect of smartphone electrocardiogram usage on anticoagulant medication compliance

PURPOSE

Compliance with anticoagulation treatment for atrial fibrillation is highly variable. Smartphone electrocardiograms that allow patients to have greater insight into their arrhythmia burden may improve anticoagulant compliance.

METHODS

Patients were enrolled if they had atrial fibrillation with a CHA₂DS₂-VASc score of 2 or more, were eligible for anticoagulation and had a smartphone. Participants were randomly assigned to receive a smartphone electrocardiogram (AliveCor Kardia) to record their electrocardiograms 5 times/week or to the control group. All patients received 6 months of anticoagulant (apixaban) dispensed as 1-month pre-loaded pill boxes.

RESULTS

A total of 100 patients were enrolled from July 2017 to August 2019, but 5 patients in the monitor arm and 1 in the control arm withdrew prematurely. The monitor and control groups did not differ in age, gender, CHA₂DS₂-VASc score, or comorbidities. Median medication compliance was 99.7%, with nonsignificantly greater compliance in the monitor group (100%) than in the control group (99.7%) (p-value = 0.247). There was also no significant difference between missing any dose and use/nonuse of the smartphone monitor (48.9% vs. 55.1%; p-value = 0.692). Mean monitor compliance was 86.8% ± 14.0% with an average of 4.34 recorded electrocardiograms per week. Monitor group patients with perfect medication compliance had significantly higher monitor compliance than those patients who missed doses (median 95.3% vs 86.7%; p-value = 0.02).

CONCLUSIONS

In a study population with higher-than-expected medication compliance, the use of smartphone electrocardiogram did not demonstrate an improvement in medication compliance as compared to usual care. Greater monitor compliance was associated with greater medication compliance.

CLINICAL TRIAL REGISTRATION

BOAT-OAR ClinicalTrials.gov number, NCT03515083.

2021 Focused update of the 2017 consensus guidelines of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation

The consensus of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation (AF) has been published in 2017 which provided useful clinical guidance for cardiologists, neurologists, geriatricians, and general practitioners in Asia-Pacific region. In these years, many important new data regarding stroke prevention in AF were reported. The Practice Guidelines subcommittee members comprehensively reviewed updated information on stroke prevention in AF, and summarized them in this 2021 focused update of the 2017 consensus guidelines of the APHRS on stroke prevention in AF. We highlighted and focused on several issues, including the importance of AF Better Care (ABC) pathway, the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) for Asians, the considerations of use of NOACs for Asian patients with AF with single 1 stroke risk factor beyond gender, the role of lifestyle factors on stroke risk, the use of oral anticoagulants during the "coronavirus disease 2019" (COVID-19) pandemic, etc. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician's decision remains the most important factor in the management of AF.

Big Data and Real-World Data based Cost-Effectiveness Studies and Decision-making Models: A Systematic Review and Analysis

Background: Big data and real-world data (RWD) have been increasingly used to measure the effectiveness and costs in cost-effectiveness analysis (CEA). However, the characteristics and methodologies of CEA based on big data and RWD remain unknown. The objectives of this study were to review the characteristics and methodologies of the CEA studies based on big data and RWD and to compare the characteristics and methodologies between the CEA studies with or without decision-analytic models. Methods: The literature search was conducted in Medline (Pubmed), Embase, Web of Science, and Cochrane Library (as of June 2020). Full CEA studies with an incremental analysis that used big data and RWD for both effectiveness and costs written in English were included. There were no restrictions regarding publication date. Results: 70 studies on CEA using RWD (37 with decision-analytic models and 33 without) were included. The majority of the studies were published between 2011 and 2020, and the number of CEA based on RWD has been increasing over the years. Few CEA studies used big data. Pharmacological interventions were the most frequently studied intervention, and they were more frequently evaluated by the studies without decision-analytic models, while those with the model focused on treatment regimen. Compared to CEA studies using decision-analytic models, both effectiveness and costs of those using the model were more likely to be obtained from literature review. All the studies using decision-analytic models included sensitivity analyses, while four studies no using the model neither used sensitivity analysis nor controlled for confounders. Conclusion: The review shows that RWD has been increasingly applied in conducting the cost-effectiveness analysis. However, few CEA studies are based on big data. In future CEA studies using big data and RWD, it is encouraged to control confounders and to discount in long-term research when decision-analytic models are not used.

Efficacy of a centralized, blended electronic, and human intervention to improve direct oral anticoagulant adherence: Smartphones to improve rivaroxaban ADHEREnce in atrial fibrillation (SmartADHERE) a randomized clinical trial

BACKGROUND

Improving adherence to direct oral anticoagulants (DOAC) is challenging, and simple text messaging reminders have not been effective.

METHODS

SmartADHERE was a randomized trial that tested a personalized digital and human direct oral anticoagulant adherence intervention compared to usual care. Eligibility required age ≥ 18, newly-prescribed (≤90 days) rivaroxaban for atrial fibrillation (AF), 1 of 4 at-risk criteria for nonadherence, and a smartphone. The intervention consisted of combination of a medication management smartphone app, daily app-based reminders, adaptive text messaging, and phone-based counseling for severe nonadherence. The primary outcome was the proportion of days covered by rivaroxaban (PDC) at 6 months. There were 25 U.S. sites, all cardiology and electrophysiology outpatient practices, activated for a target sample size of 378, but the study was terminated by the sponsor prior to reaching target enrollment.

RESULTS

There were 139 participants (age 65±9.6 years, 30% female, median CHA₂DS₂-VASc score 3 with IQR 2 to 4, mean total medication burden 7.7±4.4). DOAC adherence was high in both arms with no difference in the primary outcome (PDC 0.86±0.25 intervention vs 0.88±0.25 control, p=0.62) or in secondary outcomes including PDC ≥ 0.80 and medication persistence. Per protocol analyses had similar results. Because of the high overall PDC, the likelihood to answer the primary hypothesis was only 51% even if target enrollment were achieved. There were no study-related adverse events.

CONCLUSIONS

The use of a centralized digital and human adherence intervention was feasible across multiple sites. Overall adherence was much higher than expected despite prescreening for at-risk individuals. SmartADHERE illustrates the challenges of trials of behavioral and technology interventions, where enrollment itself may lead to selection bias or treatment effects. Pragmatic study designs, such as cluster randomization or stepped-wedge implementation, should be considered to improve enrollment and generalizability.

Adverse drug reactions with oral anticoagulants: data from sicilian spontaneous reporting system database

OBJECTIVE

Direct oral anticoagulants (DOACs) were developed to avoid the limitations of vitamin K antagonists (VKAs). DOACs are associated with a greater incidence of gastrointestinal bleeding and a smaller number of intracranial haemorrhages than VKAs. Therefore, it is important to deepen our knowledge of their safety profiles. The aim of this study was thus to analyse adverse drug reaction (ADR) reports on DOACs and VKAs using the Sicilian Spontaneous Reporting System (SRS) database.

METHODS

All ADR reports with DOACs and VKAs as suspected drugs that were entered into the Sicilian SRS database during the period 2001-2019 were selected. In detail, all reports with the following single active substances were included: dabigatran etexilate, rivaroxaban, apixaban and edoxaban; acenocoumarol and warfarin were included as a comparator group. Descriptive statistical methodology was used to evaluate characteristics of the reported cases with a case-by-case assessment.

RESULTS AND DISCUSSION

Out of 521 reports related to anticoagulants, 444 (85.2%) and 77 (14.8%) involved DOACs and VKAs, respectively. DOAC-related reports were mainly of gastrointestinal disorders. In contrast, VKAs were mostly associated with blood and lymphatic system disorders, injury, investigations and vascular disorders. Many more cases of ADRs in the form of gastrointestinal disorders concerned dabigatran etexilate (n = 179, 73.7%) than the other DOACs, while ADRs in the form of blood disorders were mainly associated with acenocoumarol (n = 27, 57.4%). The most commonly reported Preferred Terms for DOACs were dyspepsia (n = 89, 17.1%), upper abdominal pain (n = 41, 9.2%) and pruritus (n = 26, 5.8%), whereas for VKAs, they were anaemia (n = 21, 27.3%) and hypocoagulable state (n = 18, 3.5%). Potentially interacting concomitant medications particularly included antithrombotic agents (n = 19, 4.3%) for DOACs and proton-pump inhibitors (PPIs) (n = 37, 48.1%) and antithrombotic agents (n = 13, 16.9%) for VKAs.

CONCLUSION

The ADRs most commonly associated with DOACs, especially dabigatran, were gastrointestinal disorders, particularly gastrointestinal bleeding. Our study also highlights the potential role of drug-drug interactions in the ADRs. The cases of gastrointestinal bleeding highlight the need for careful prescribing of DOACs and use of potentially interacting concomitant drugs.

Anti-FXa-IIa activity test in Asian and its potential role for drug adherence evaluation in patients with direct oral anticoagulants: a nationwide multi-center synchronization study

BACKGROUND

The data of anti-FXa-IIa activity detection in Asian population is insufficient, and its potential role for drug adherence evaluation in patients with direct oral anticoagulants (DOACs) remains unclear. This study carried out multi-center anti-FXa-IIa activity detection in Asian, aiming to explore its applicability in Asian population and find its role in adherence evaluation.

METHODS

We assessed patients' self-reported adherence using the Morisky, Green, and Levine Adherence Scale (MGLS) from six hospitals. Plasma samples were collected for peak and trough concentration determination, and anti-FXa-IIa chromogenic assay was conducted using rivaroxaban/dabigatran calibrators and controls. Multivariate logistic regression models, covariate adjustment and spearman's two-tailed test were conducted in the data analysis. This study had been registered in clinical trials (NCT03666962).

RESULTS

In total, 271 patients taking rivaroxaban (n=149) or dabigatran (n=122) were enrolled. Among the 271 patients assessed by MGLS questionnaire, 188 persons (69.4%) showed high adherence, 77 persons (28.4%) was in intermediate adherence group, and only 6 patients (2.2%) had low adherence. Patients are more adherent dosed once daily of rivaroxaban compared to twice daily of dabigatran: 75.6% vs. 63.6%. Anti-FXa-IIa activity had good linear correlation with routine coagulation indexes (P<0.001), but no significant association was found between drug adherence and anti-FXa-IIa activity (P>0.05).

CONCLUSIONS

This study confirms that anti-FXa-IIa activity detection based on target drug calibrations can be used as an effective index for pharmacodynamic evaluation in Asian population, but had limited value in drug adherence evaluation for DOACs. As the limited samples, these findings could serve as a hypothesis-generating effort, and should be validated in further studies with larger sample sizes.

A comprehensive appraisal of dabigatran etexilate clinical evidence and applications: a 10-year-long story

During the last decade, non-vitamin K antagonist oral anticoagulants (NOACs) revolutionized the thromboprophylaxis management of several medical conditions, including atrial fibrillation and venous thromboembolism. Dabigatran etexilate was the first NOAC widely available worldwide, and it is currently the only one that directly inhibits thrombin. More recently, the availability of idarucizumab, a specific reversal agent, has increased the safety of dabigatran use in clinical practice, especially for those patients with severe and life-threatening bleeding. This review aims to summarize current evidence on dabigatran, starting from its pharmacological characteristics, and providing an updated overview of pivotal randomized controlled trials and real-world data on its efficacy and safety.

Engaging Patients in Atrial Fibrillation Management via Digital Health Technology: The Impact of Tailored Messaging

Patients with atrial fibrillation (AF) demonstrate persistent knowledge gaps regarding their condition and a substandard adherence to oral anticoagulant (OAC) medication, which contribute to thromboembolic stroke and other clot-related complications. Tailored patient education and medication reminders may help reduce these negative health outcomes. We sought to improve disease knowledge and medication adherence among a sample of AF patients using tailored education and nudges. The intervention leveraged three digital health technologies: a patient portal, an electronic-prescribing data feed, and a smart pill bottle. The content of the educational messaging, nudges, and cadence were tailored according to findings from our user-centered design studies and delivered via a patient portal (MyChart®; Epic Systems, Verona, WI, USA), with which participants were familiar. In a six-month randomized controlled trial with parallel groups, we used MyChart® to send educational messages and medication reminders according to a decision tree that emerged from our prior user-centered design studies. The intervention group demonstrated higher AF knowledge at study completion than the control group and more MyChart® logins throughout the trial, suggesting intervention uptake. Women were more adherent than men and patients diagnosed more than one year ago were more adherent than those with more recent diagnoses. The intervention and control group adherence rates were 93.1% and 89.5%, respectively; intervention effect was moderated by age, medication type, and prior MyChart® use. Within the intervention group, younger patients, those taking once-daily rivaroxaban, and those who were less active MyChart® users prior to the study benefited relative to their control group counterparts. Tailored educational and reminder messages contributed to increased adherence and disease knowledge among AF patients, though certain patient characteristics moderated the intervention's effectiveness. Technology-based health interventions can be useful for older adults with effective tailoring and training.

Persistence with Anticoagulation for Atrial Fibrillation: Report from the GLORIA-AF Phase III 1-Year Follow-up

Background: We aimed to assess the extent to which drug persistence is better with non-vitamin K antagonist oral anticoagulants (NOACs) than vitamin K antagonists (VKAs) in atrial fibrillation (AF) patients and to estimate the difference in therapy persistence depending on NOAC dosing regimen (once daily (QD) vs. twice daily (BID)). Methods: Consecutive patients were followed for 1 year in phase III of the GLORIA-AF registry. Drug persistence was defined as the use of OAC without any discontinuation in >30 days or switching to alternative therapy. Results: Among 21,109 eligible patients in phase III, 17,266 patients who were prescribed OAC at baseline and those who took ≥1 OAC dose were included. The 1-year proportion of patients receiving NOAC and VKA who persisted on treatment was 80% and 75%, respectively. The 1-year persistence with NOACs BID and NOACs QD was 81% and 80%, respectively. Female gender, hypertension, older age, alcohol use, permanent, asymptomatic, and minimally symptomatic AF were associated with better OAC persistence. Region, medication usage predisposing to bleeding, being a current smoker, treatment reimbursement, and proton pump inhibitors were associated with lower OAC persistence. Conclusions: Drug persistence was higher with NOACs (1-year persistence was 80%) than with VKAs (75%). There was little difference in 1-year persistence between NOAC dosing regimens.

Methodological considerations for investigating oral anticoagulation persistence in atrial fibrillation

Aims 

Reports of long-term oral anticoagulant (OAC) therapy for atrial fibrillation (AF) reveal highly variable, and generally suboptimal estimates of medication persistence. The objective of this review is to summarize current literature and highlight important methodological considerations for interpreting persistence research and designing studies of persistence on OAC treatment.

Methods and results 

We summarize differences in study methodology, setting, timing, treatment, and other factors associated with reports of better or worse persistence. For example, prospective compared with retrospective study designs are associated with higher reported persistence. Similarly, patient factors such as permanent AF or high stroke risk, and treatment with non-vitamin K oral antagonists relative to vitamin K antagonists are associated with higher persistence. Persistence has also been reported to be higher in Europe compared with North America and higher when the treating physician is a general practitioner compared with a specialist. We propose a framework for assessing and designing persistence studies. This framework includes aspects of patient selection, reliability and validity of measures, persistence definitions, clinical utility of measurements, follow-up periods, and analytic approaches.

Conclusions 

Differences in study design, patient selection, treatments, and factors such as the countries/regions where studies are conducted or the type of treating physician may help explain the variability in OAC persistence estimates. A framework is proposed to assess persistence studies. This may have utility to compare and interpret published studies as well as for planning of future studies.

Self-reported therapy adherence and predictors for nonadherence in patients who switched from vitamin K antagonists to direct oral anticoagulants

BACKGROUND

Many patients who used vitamin K antagonists (VKAs) for long-term prevention of thromboembolism are now actively switched to a direct oral anticoagulant (DOAC). Strict adherence to a DOAC is crucial for its success. However, therapy adherence and clinical factors that predict nonadherence are currently not well studied among patients who switched from a VKA to a DOAC.

METHODS

A questionnaire was developed and sent to 2920 former patients of 3 anticoagulation clinics in the Netherlands, who switched from a VKA to a DOAC between January 2016 and December 2017. Questions concerned demographics, treatment persistence, adherence, and the occurrence of bleeding or thromboembolic events on DOACs. To identify predictors for nonadherence, logistic regression models were used to estimate crude and age/sex-adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

A total of 1399 questionnaires (response rate 48%) were used for analysis. DOAC treatment persistence (94%) and adherence (86%) rates were high. Several predictors of nonadherence were identified, including young age (OR, 5.9; 95% CI, 3.6-9.8 for <60 years compared to >75 years), low consultation frequency with a specialist (OR, 1.6; 95% CI, 1.1-2.2), a history of minor bleeding on DOACs (OR, 1.9; 95% CI, 1.3-2.8), and a twice-daily dosing regimen (OR, 1.9; 95% CI, 1.3-2.6).

CONCLUSIONS

Self-reported treatment persistence and adherence were high in our study population, and several predictors of nonadherence were identified. Factors that can be influenced (low consult frequency with medical specialist, daily dosing regimen) may be used to improve therapy adherence.

The optimal drug adherence to maximize the efficacy and safety of non-vitamin K antagonist oral anticoagulant in real-world atrial fibrillation patients

Aims

To investigate the association between adherence to non-vitamin K antagonist oral anticoagulant (NOAC) and clinical outcomes and to determine the optimal cut-off level of NOAC adherence among patients with atrial fibrillation (AF).

Methods and results

Using the Korean National Health Insurance Service database, we identified 96 197 patients with non-valvular AF who initiated NOAC or warfarin in 2013–16. We compared clinical outcomes between adherent [proportion of days covered (PDC) ≥80%] vs. non-adherent (PDC &lt;80%) NOAC users, and further with warfarin users. We assessed the outcomes according to different levels of adherence. The proportion of adherent NOAC users was 64.0%. Compared with non-adherent NOAC users, adherent NOAC users were at lower risks of ischaemic stroke/systemic embolism (SE) [adjusted hazard ratio (aHR) 0.73, 95% confidence interval (CI) 0.69–0.79], and myocardial infarction (aHR 0.82, 95% CI 0.72–0.93), whereas there was no significant risk alteration for major bleeding (aHR 1.01, 95% CI 0.91–1.11). Compared with warfarin, non-adherent NOAC use failed to have better efficacy against ischaemic stroke/SE (aHR 0.99, 95% CI 0.93–1.05) and rather had increased risk of myocardial infarction (aHR 1.13, 95% CI 1.03–1.25). In NOAC users, the risks of adverse outcomes decreased according to gradual increase of adherence rates with the lowest risks in ≥90%, except for major bleeding in which there were no significant associations.

Conclusions

In an adherence level-dependent fashion, adherent use of NOAC showed better clinical outcomes without increasing bleeding risk. Maintaining ≥90% of adherence optimizes effectiveness of NOAC therapy without compromising its safety.

The daily practice of direct oral anticoagulant use in patients with atrial fibrillation; an observational cohort study

BACKGROUND

Direct oral anticoagulants (DOACs) are administered in fixed doses without monitoring. There is still little published data on the impact of the absence of monitoring on adherence to medication and stability of DOAC plasma levels over time.

OBJECTIVES

To explore adherence and stability of DOAC plasma levels over time in patients with atrial fibrillation (NVAF) recently started on DOAC therapy.

PATIENTS AND METHODS

A prospective observational cohort study with structured follow up including assessment of adherence to medication, plasma levels at baseline, 3,6 and 12 months and adverse events.

RESULTS

We included 164 patients; 89% were previous users of a vitamin K antagonist (VKA). One-year adherence was reasonably good: Morisky adherence measurement scores of 6-8 in 92%. The majority of DOAC plasma levels were within reported on-therapy ranges; dabigatran (median 104.4 ng/ml, IQR 110.2), rivaroxaban (median 185.2 ng/ml, IQR 216.1) and on average levels were not different for full and adjusted doses. There was significant variation between patients, but no significant differences over time within individuals. A substantial proportion of patients starting in the upper-or lower 20th percentiles remained there during the entire follow up. Seventeen bleedings (16 minor, 1 major) were reported, no ischemic events and bleeding or thrombotic events were not associated with DOAC plasma levels.

CONCLUSIONS

Adherence was reasonably good in the majority of patients. Our data confirm the stability of DOAC plasma levels over time. Knowledge of such data may, in the individual patient, contribute to optimal drug and dose selection.

Medication taking behaviors in patients taking warfarin versus direct oral anticoagulants: A systematic review

Introduction: This article aims to compare medication adherence and persistence between warfarin and direct oral anticoagulants (DOACs) and identify reported adherence barriers. As with other chronic illness, medication nonadherence continues to be a problem and appropriate adherence to long-term anticoagulation therapy is needed to improve patient health outcomes and to reduce health expenditure associated with hospitalizations and emergency visits. Areas covered: Warfarin and DOACs such as apixaban, rivaroxaban, edoxaban, and dabigatran have demonstrated effectiveness in the management of atrial fibrillation (AF), deep vein thrombosis (DVT), and pulmonary embolism (PE). Adherence and long-term persistence to oral anticoagulants is highly associated with reduced adverse events. A systematic literature search from 2013 to 2018 examined the primary outcome of adherence and persistence. Expert opinion: Currently, warfarin is less preferred over DOACs due to associated complications like narrow therapeutic window, inconvenience, and increased risk of adverse events. At the same time, the lack of monitoring with DOACs in combination with cost issues may negatively impact medication adherence. Examining adherence barriers identified in the literature is the first step to designing effective interventions aimed at enhancing adherence in this high-risk population.

Differences between patient-driven adherence to vitamin K antagonists and direct oral anticoagulants. Do few missed doses matter? ACO-MEMS Study

INTRODUCTION

Lack of INR controls might affect the adherence to direct oral anticoagulants (DOAC). The vast majority of studies that addresses adherence to anticoagulants are retrospective and based on pharmacy refill data. Our aim was to compare the adherence between vitamin K antagonists (VKA) and DOAC and to analyze the clinical relevance of non-adherence.

MATERIALS AND METHODS

A prospective two-arm observational cohort study was performed in two Spanish public hospitals. Adherence was assessed by Medication Event Monitoring System. Relationship between adherence and events during follow-up and time in therapeutic range (TTR) in the VKA group were analyzed.

RESULTS

257 patients were included (132 DOAC and 125 VKA). Monitoring time was 120 days (101-133). Patients in VKA group showed higher taking adherence (97.9% vs. 95.8%) and less non-adherent patients of >5% and >10% of the doses, without differences in >20% of the doses. Taking adherence was strongly associated with TTR (AUC: 0.89, CI 95%: 0.81-0.97 of TTR for detection of non-adherent patients of >10% of doses). During a follow-up of 1.8 years (1.6-2) non-adherent patients of >5% of doses presented more thromboembolic events (HR 6.1, CI95% 1.3-28.1).

CONCLUSIONS

Although adherence to oral anticoagulant therapy was excellent, it was higher to VKA than to DOAC. Time in therapeutic range was highly sensitive to few missed doses of AVK. Non-adherence of >5% of prescribed doses had high clinical relevance.

Persistence on apixaban in atrial fibrillation patients: a retrospective multicentre study

AIMS

Real-world data on treatment persistence, safety and effectiveness of non-Vitamin K antagonist oral anticoagulants (NOACs) play an important role in the assessment of risks and benefits of these drugs. Our aim was to evaluate persistence on treatment, incidence of major bleeding and incidence of a composite endpoint of major events, including all-cause death, myocardial infarction, stroke and systemic thromboembolism, during treatment with apixaban in a cohort of patients with nonvalvular atrial fibrillation (NVAF).

METHODS

In this multicentre retrospective observational study, we retrieved data from medical records of five Italian hospitals on patients with a diagnosis of NVAF who initiated apixaban between 1 January 2014 and 31 March 2016 and had a first subsequent visit at the same hospital.

RESULTS

We studied 766 patients with mean age of 74.2 (standard deviation 11.1) years and median CHADS2 and CHA2DS2VASc scores of 2.0 and 4.0, respectively. Over a median follow-up period of 339 days, persistence on treatment was 83.5% [95% confidence interval (95% CI) 75.5-89.1%]. The rate of major bleeding (per 100 person-years) was 1.15 (95% CI 0.39-1.90 per 100 person-years), while the cumulative incidence was 4.4% (95% CI 1.6-12.0). The rate of major events was 1.97 (95% CI 1.08-2.86) per 100 patient-years, with a cumulative incidence over the entire follow-up period of 7.7% (95% CI 4.6-12.8).

CONCLUSION

In real-life conditions, NVAF patients treated with apixaban show rates of treatment discontinuation and major bleedings, which are comparable to those found in the ARISTOTLE pivotal study, thus supporting its external validity.

Risk factors for medication non-adherence among atrial fibrillation patients

Background

Atrial fibrillation (AF) patients are routinely prescribed medications to prevent and treat complications, including those from common co-occurring comorbidities. However, adherence to such medications may be suboptimal. Therefore, we sought to identify risk factors for general medication non-adherence in a population of patients with atrial fibrillation.

Methods

Data were collected from a large, ethnically-diverse cohort of Kaiser Permanente Northern and Southern California adult members with incident diagnosed AF between January 1, 2006 and June 30, 2009. Self-reported questionnaires were completed between May 1, 2010 and September 30, 2010, assessing patient socio-demographics, health behaviors, health status, medical history and medication adherence. Medication adherence was assessed using a previously validated 3-item questionnaire. Medication non-adherence was defined as either taking medication(s) as the doctor prescribed 75% of the time or less, or forgetting or choosing to skip one or more medication(s) once per week or more. Electronic health records were used to obtain additional data on medical history. Multivariable logistic regression analyses examined the associations between patient characteristics and self-reported general medication adherence among patients with complete questionnaire data.

Results

Among 12,159 patients with complete questionnaire data, 6.3% (n = 771) reported medication non-adherence. Minority race/ethnicity versus non-Hispanic white, not married/with partner versus married/with partner, physical inactivity versus physically active, alcohol use versus no alcohol use, any days of self-reported poor physical health, mental health and/or sleep quality in the past 30 days versus 0 days, memory decline versus no memory decline, inadequate versus adequate health literacy, low-dose aspirin use versus no low-dose aspirin use, and diabetes mellitus were associated with higher adjusted odds of non-adherence, whereas, ages 65–84 years versus < 65 years of age, a Charlson Comorbidity Index score ≥ 3 versus 0, and hypertension were associated with lower adjusted odds of non-adherence.

Conclusions

Several potentially preventable and/or modifiable risk factors related to medication non-adherence and a few non-modifiable risk factors were identified. These risk factors should be considered when assessing medication adherence among patients diagnosed with AF.

Comparison of Drug Switching and Discontinuation Rates in Patients with Nonvalvular Atrial Fibrillation Treated with Direct Oral Anticoagulants in the United States

Introduction

Continuous usage of direct oral anticoagulants (DOACs) among nonvalvular atrial fibrillation (NVAF) patients is essential to maintain stroke prevention. We examined switching and discontinuation rates for the three most frequently initiated DOACs in NVAF patients in the USA.

Methods

Patients who initiated apixaban, rivaroxaban, or dabigatran (index event/date) were identified from the Pharmetrics Plus claims database (Jan 1, 2013–Sep 30, 2016, includes patients with commercial and Medicare coverage) and grouped into cohorts by index DOAC. Patients were required to have a diagnosis of NVAF and continuous health plan enrollment for 12 months prior to the index date (baseline period) and at least 3 months during the follow-up period. Drug switching rates to any other DOAC or warfarin and index DOAC discontinuation rate were evaluated separately with descriptive statistics, Kaplan–Meier analysis, and multivariable Cox regression analysis.

Results

Of the NVAF study population (n = 41,864), 37% initiated apixaban (n = 15,352; mean age 62 years), 51% initiated rivaroxaban (n = 21,250; mean age 61 years), and 13% initiated dabigatran (n = 5262; mean age 61 years). During the follow-up period, the unadjusted drug switching rates of patients treated with apixaban, rivaroxaban, and dabigatran were 3.6%, 6.3%, and 11.1%, respectively (p < 0.001 across the three cohorts); while the index DOAC discontinuation rates were 52.8%, 60.3%, and 62.9%, respectively (p < 0.001). After we controlled for differences in patient characteristics, patients treated with rivaroxaban (HR 1.8; 95% CI 1.6–2.0; p < 0.001) and dabigatran (HR 3.4; 95% CI 3.0–3.8, p < 0.001) had a significantly greater likelihood for drug switching than patients treated with apixaban. Also, both rivaroxaban (HR 1.1; 95% CI 1.1–1.2, p < 0.001) and dabigatran (HR 1.3; 95% CI 1.2–1.3, p < 0.001) treated patients were more likely to discontinue treatment.

Conclusion

In the real-world setting, patients with NVAF newly treated with apixaban were less likely to switch or discontinue treatment compared to patients treated with rivaroxaban or dabigatran.

Funding

Pfizer and Bristol-Myers Squibb.

Non-bleeding Adverse Events with the Use of Direct Oral Anticoagulants: A Sequence Symmetry Analysis

Introduction

Postmarketing pharmacovigilance reports have raised concerns about non-bleeding adverse events associated with direct oral anticoagulants (DOACs), but only limited results are available from large claims databases.

Objective

The aim of this study was to assess the potential association between DOAC initiation and the onset of four types of non-bleeding adverse events by sequence symmetry analysis (SSA).

Methods

SSA was performed using nationwide data from the French National Healthcare databases (Régime Général, 50 million beneficiaries) to assess a cohort of 386,081 DOAC new users for the first occurrence of four types of non-bleeding outcomes: renal, hepatic, skin outcomes identified by using hospitalization discharge diagnoses, and gastrointestinal outcomes by using medication reimbursement. Asymmetry in the distribution of each investigated outcome occurring before and after initiation of DOAC therapy was used to test the association between DOAC therapy and these outcomes. SSA inherently controls for time-constant confounders, and adjusted sequence ratios were computed after correcting for temporal trends. Negative (glaucoma) and positive (bleeding, depressive disorders) control outcomes were used and analyses were replicated on a cohort of 310,195 patients initiating a vitamin K antagonist (VKA).

Results

This study demonstrated the expected positive association between either DOAC or VKA therapy and hospitalised bleeding and initiation of antidepressant therapy, while no association was observed between either DOAC or VKA therapy and initiation of antiglaucoma medications. For DOAC therapy, signals were the associations with hepatic outcomes, including acute liver injury [for the 3-month time window, aSR₃ = 2.71, 95% confidence interval (CI) 1.79–4.52]; gastrointestinal outcomes, including initiation of drugs for constipation and antiemetic drugs (aSR₃ = 1.31, 95% CI 1.27–1.36; and 1.17, 95% CI 1.12–1.22, respectively); and kidney diseases (aSR₃ = 1.33, 95% CI 1.29–1.37).

Conclusion

Results of this nationwide study suggest that DOACs are associated with rare but severe liver injury and more frequent gastrointestinal disorders. A low risk of kidney injury with DOAC therapy can also not be excluded.

Electronic supplementary material

The online version of this article (10.1007/s40264-018-0668-9) contains supplementary material, which is available to authorized users.

Pharmacokinetics of new oral anticoagulants: implications for use in routine care

INTRODUCTION

Since 2008, new oral anticoagulants (NOACs) have been approved for the prevention of venous thromboembolism (VTE) in patients receiving hip or knee replacement surgery, prevention of stroke and systemic embolism in patients with non-valvular atrial fibrillation (NVAF), treatment of deep vein thrombosis (DVT), and pulmonary embolism (PE). Premarketing randomized clinical trials (RCTs) of NOACs demonstrated their non-inferiority in terms of efficacy vs. warfarin (traditional oral anticoagulant - TOA), with lower risk of serious adverse drug reactions, especially cerebral hemorrhages. In clinical practice, pharmacokinetic aspects of NOACs have to be carefully taken into account to optimize the benefit-risk profile of these drugs. Areas covered: An overview of major issues related to pharmacokinetics of NOACs, such as drug-drug interactions, over- and underdosage in special populations (e.g. elderly, underweight, and chronic kidney disease patients), and impact on adherence and persistence to NOACs therapy and ultimately clinical outcomes in real-world setting, is provided. Expert opinion: NOACs have been proven to be a better option than traditional anticoagulants due to better tolerability and ease of use. However, given specific pharmacokinetic characteristics, NOAC therapy has to be carefully tailored and monitored in relation to patient characteristics with the final goal of maximizing benefits and minimizing risks.

Secondary adherence to non-vitamin-K antagonist oral anticoagulants in patients with atrial fibrillation in Sweden and the Netherlands

OBJECTIVE

There is limited evidence on patients' adherence and the impact of the prescribed dosing regimen in non-vitamin-K oral anticoagulants (NOACs). We aimed to assess secondary adherence to NOACs and to determine the impact of the dosing regimen in patients with atrial fibrillation.

METHODS

Patients using a NOAC between 2009 and 2013 were identified from the nation-wide Swedish Prescribed Drug Register and the Dutch regional IADB.nl database. Patients using a consistent dosage for at least 180 consecutive days were included. Adherence was calculated using the medication possession ratio (MPR) and adjusted for overlapping dates. Adherence was defined as a MPR ≥0.8. Sensitivity analyses were performed using a MPR ≥0.9. Logistic regression was performed to compare secondary adherence and to explore the influence of the dosing regimen.

RESULTS

A total of 5254 Swedish and 430 Dutch NOAC users were included. The mean MPR was 96.0% (SD 7.8%) in Sweden and 95.1% (SD 10.1%) in the Netherlands. Multivariable logistic regression analysis showed that a twice daily regimen had a lower likelihood of being secondary adherent compared to a once daily regimen in Sweden (odds ratio [OR] 0.21 [95% CI 0.12-0.35]).

LIMITATIONS

The influence of selection bias introduced by the inclusion criterion of ≥2 dispensations covering at least 180 days could not be excluded.

CONCLUSIONS

This study demonstrated that secondary adherence was high in this specific setting among patients with at least two initial dispensations of a NOAC covering a minimum of 180 days. The use of NOACs in a once daily regimen showed higher adherence compared to a twice daily regimen.

Association between medication adherence and illness perceptions in atrial fibrillation patients treated with direct oral anticoagulants: An observational cross-sectional pilot study

OBJECTIVE

The aim of this study was to examine the association between medication adherence and illness perceptions, and to explore the factors associated with poor medication adherence in atrial fibrillation (AF) patients receiving direct oral anticoagulants (DOACs) in a real-world clinical setting.

METHODS

An observational cross-sectional pilot study was conducted at a single Japanese university hospital. One hundred and twenty-nine patients who were diagnosed with AF and who were taking DOACs were recruited from outpatients between January 4th and April 25th, 2017. We evaluated medication adherence to DOACs using the Morisky Medication Adherence Scale-8 (MMAS-8) and illness perceptions using the Brief Illness Perception Questionnaire (BIPQ). The patients' characteristics and clinical data were collected from electronic medical records.

RESULTS

Ninety-nine (76.7%) patients (male, n = 74; mean age, 71.4±9.8 years) participated in this study. According to the MMAS-8, 21 (21.2%) of the patients were classified into the poor adherence group (MMAS-8 score of <6), and 78 (78.8%) were classified into the good adherence group (MMAS-8 score of 6-8). A multivariate logistic regression analysis revealed that age (per year, odds ratio [OR] 0.912, 95% confidence interval [CI] 0.853-0.965, p = 0.001), a history of warfarin use (OR 0.181, 95% CI 0.033-0.764, p = 0.019), duration of DOAC exposure (per 100 days, OR 1.245, 95% CI 1.084-1.460, p = 0.001), and the BIPQ emotional response score (per 1 point, OR 1.235, 95% CI 1.015-1.527, p = 0.035) were significantly associated with poor medication adherence in AF patients receiving DOACs.

CONCLUSION

Poor medication adherence to DOACs was strongly associated with a stronger emotional response (i.e. stronger feelings of anger, anxiety, and depression), as well as younger age, the absence of a history of warfarin treatment, and longer DOAC exposure. Further evaluation of the factors associated with medication adherence in AF patients and the development and execution of strategies for improving poor adherence are warranted in the real-world clinical setting.

Primary Nonadherence to Oral Anticoagulants in Patients with Atrial Fibrillation: Real-World Data from a Population-Based Cohort

BACKGROUND

Primary nonadherence (not filling a first prescription) is an important yet unstudied aspect of adherence to oral anticoagulant (OAC) therapy.

OBJECTIVE

To estimate the rates of primary nonadherence to OACs and determine associated factors in real-world practice.

METHODS

This population-based retrospective cohort study set in the Valencia region of Spain (about 5 million inhabitants) included all patients with atrial fibrillation who were newly prescribed OACs during 2011-2014 (N = 18,715). Primary nonadherence was obtained by linking electronic prescription and dispensing data and assessed by type of OAC-vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs). Covariates were obtained from diverse databases, including electronic medical records. Multivariate logistic regression models were used to assess characteristics associated with primary nonadherence, adjusting for a propensity score to minimize confounding by indication.

RESULTS

Primary nonadherence to OACs was 5.62% (VKA 4.29% vs. NOAC 10.81%; P < 0.001), with varying rates among specific drugs (acenocoumarol 4.2%, warfarin 10.9%, apixaban 5.0%, dabigatran 7.9%, and rivaroxaban 15.5%). After adjusting for potential confounders, the likelihood of not filling the first prescription was higher for NOAC patients than for VKA patients (OR = 2.76, 95% CI = 2.41-3.15). High coinsurance in the older groups (OR = 2.63, 95% CI = 1.47-4.69 for patients aged 66-75 years and OR = 3.02, 95% CI = 1.58-5.76 for patients aged > 75 years); being a non-Spanish European (OR = 1.49, 95% CI = 1.12-1.99); and having dementia (OR = 1.72, 95% CI = 1.37-2.16) were positively associated with primary nonadherence. Electronic transmission of prescriptions (OR = 0.85, 95% CI = 0.74-0.96); liver disease (OR = 0.73, 95% CI = 0.54-0.99); and polypharmacy (OR = 0.59, 95% CI = 0.50-0.70) were inversely associated with primary nonadherence.

CONCLUSIONS

Overall, primary nonadherence to OACs was relatively low (5%). However, important differences were found between VKAs and NOACs. After adjustment, patients prescribed NOACs nearly tripled the likelihood of nonadherence compared with patients prescribed VKAs, which could negatively affect their effectiveness in clinical practice. Identified correlates were similar to those shown in the limited evidence for other medications.

DISCLOSURES

This work was partially supported by the 2013 Collaboration Agreement between the Fundación para el Fomento de la Investigación Sanitaria y Biomédica (FISABIO) from the Valencia Ministry of Health and Boehringer Ingelheim, a nonconditioned program to conduct independent research in chronic health care, pharmacoepidemiology, and medical practice variation. Rodriguez-Bernal was funded by the Instituto de Salud Carlos III, Spanish Ministry of Health, and cofinanced by the European Regional Development Fund (grant number RD12/0001/0005). The views presented here are those of the authors and not necessarily those of the FISABIO Foundation, the Valencia Ministry of Health, or the study sponsors. The funding sources had no access to study data and did not participate in any way in the design or conduct of the study, data analysis, decisions regarding the dissemination of findings, the development of the manuscript, or its publication. Peiró has received fees for participation in scientific meetings and courses sponsored by Novartis and Ferrer International. In 2014, Sanfélix-Gimeno participated in an advisory meeting of Boehringer Ingelheim. García-Sempere is a former employee of Boehringer Ingelheim. Rodriguez-Bernal and Hurtado have no relationships relevant to the contents of this article to disclose. This work was previously submitted as an abstract (podium presentation) at the 31st International Society of Pharmacoepidemiology (ISPE) Annual Conference; August 22-26, 2015; Boston, Massachusetts.

Strategies for improving dabigatran adherence for stroke prevention in patients with non-valvular atrial fibrillation: education and drug intake reminders (FACILITA study)

Objective To assess the efficacy of a mixed intervention, educational, and reminder calendar of the intake, as a strategy to improve therapeutic adherence with dabigatran in patients with non-valvular atrial fibrillation (NVAF). Methods This was a prospective, longitudinal, multi-center study, carried out in 110 specialized healthcare centers in Spain. Seven hundred and twenty-six patients treated with dabigatran prescribed for stroke prevention were included. A cluster randomization was performed based on two groups: (1) Control Group (CG) as usual clinical practice, and (2) Intervention Group (IG) with a mixed strategy: (a) Healthcare education, and (b) Use of a reminder calendar for taking the anticoagulant medication. Three visits took place: baseline and follow-up at 6 and 12 months. Compliance was measured by using electronic monitors (MEMS). Average adherence percentage (%; Average AP) and daily compliance (%; Daily AP) was calculated. A patient was considered adherent when AP was 80-100%. Results Six hundred and twenty-five patients completed the study (315 in the IG and 310 in the CG). Daily AP was 91.97% at 6 months and 91.05% after 12 months in the IG and 82.26% and 82.63% in the CG. Average adherence was 90.79% and 89.20% in the IG and 64.51% and 63.22% in the CG at 6 and 12 months, respectively. Significant differences were observed in the Daily AP and Average AP, with higher percentages in the IG. In the non-adherents group, the number of concomitant drugs, baseline, and 6 months SBP values, 6 and 12 months DBP values, and weight, total cholesterol, and LDL cholesterol were significantly higher. The number needed to treat (NNT) was 3.84 patients to prevent one non-adherence. Conclusions A mixed intervention, consisting of patient education and a simple calendar reminder of drug intake, is an effective strategy to improve dabigatran therapeutic adherence in patients with NVAF. The percentage of adherence with dabigatran was high.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 2

The choice of oral anticoagulant (OAC) for patients with atrial fibrillation (AF) may be influenced by individual clinical features or by patterns of risk factors and comorbidities. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. non-vitamin K oral anticoagulants (NOACs) for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In addition, we discuss the timing of initiation of anticoagulation. In the second of a two-part review, we discuss the use of NOAC for stroke prevention in the following subgroups of patients with AF: (vii) secondary stroke prevention in patients after stroke or transient ischaemic attack (TIA), (viii) patients with acute stroke requiring thrombolysis or thrombectomy, (ix) those initiating or restarting OAC treatment after stroke or TIA, (x) those with renal impairment on dialysis, (xi) the elderly, (xii) those at high risk of gastrointestinal bleeding, and (xiii) those with hypertension. In addition, we discuss adherence and compliance. Finally, we present a summary of treatment suggestions. In specific subgroups of patients with AF, evidence supports the use of particular NOACs and/or particular doses of anticoagulant. The appropriate choice of treatment for these subgroups will help to promote optimal clinical outcomes.

NOACs replace VKA as preferred oral anticoagulant among new patients: a drug utilization study in 560 pharmacies in The Netherlands

BACKGROUND

In 2012, around 400.000 patients in the Netherlands were treated with Vitamin K Antagonists (VKA) for thromboembolic diseases. Since 2011, non-VKA oral anticoagulants (NOACs) are available. NOACs do not require frequent INR monitoring which benefits patients, but also imposes a risk of reduced therapy adherence. The objective of this study is to describe uptake and patient adherence of NOACs in The Netherlands until October 2016.

METHODS

Prescription data for 247.927 patients across 560 pharmacies were used to describe patient profiles, uptake of NOACs among new naive patients and switch between VKA and NOACs, and calculate therapy adherence as the Proportion of Days Covered (PDC).

RESULTS

During the studied period the share of NOACs in oral anticoagulants has grown to 57% of prescriptions to new patients. More than 70% of new NOAC users were new naive patients and around 26% switched from VKA. The overall share of NOACs among starters is largest in the group of patients of 50-80 years. Calculated compliance rate for NOAC patients shows that 88% of all users are adherent with a PDC higher than 80%.

CONCLUSIONS

NOAC have overtaken VKA as the major treatment prescribed to new oral anticoagulant patients, and the number of starters on VKA is decreasing. Patients are generally adherent to NOACs during the implementation phase, the period that the medication is used. Fear for inadherence by itself does not need to be a reason for not prescribing NOACs instead of VKA.

Drug Adherence in Patients With Nonvalvular Atrial Fibrillation Taking Non-Vitamin K Antagonist Oral Anticoagulants in Turkey: NOAC-TR

Adherence to non-vitamin K antagonist oral anticoagulants (NOACs) is an important factor for ensuring efficacy and safety in nonvalvular atrial fibrillation (NVAF). There are controversial results regarding NOAC adherence in real-world data and there are no data about NOAC adherence in Turkish population. This study investigated the NOAC adherence based on self-report, factors affecting nonadherence, and the relation of the adherence level with efficacy and safety outcomes. This multicenter cross-sectional study included 2738 patients (59% female) using NOAC (dabigatran, apixaban, and rivaroxaban) due to NVAF for more than 3 months with >30 days of supply between September 1, 2015, and February 28, 2016. To measure the adherence level, an 8-item Morisky Medication Adherence Scale was used. The mean age of the patients was 70 ± 10 years. Of the 2738 patients, 44% were receiving dabigatran, 38% rivaroxaban, and 18% apixaban. A total of 630 (23%) patients had high medication adherence, 712 (26%) moderate adherence, and 1396 (51%) low adherence. Nonadherence had related to stroke (5.6% vs 2.5%, P < .001) and minor (21.2% vs 11.1%, P < .001) and major (6.1% vs 3.7%, P = .004) bleeding rates. The adherence to NOAC was found to be quite low in Turkey. Nonadherence is associated with bleeding and thromboembolic cardiovascular events. Age, taking NOAC twice a day, and the additional noncardiac diseases, depression, and dementia were the independent factors affecting poor medication adherence.

Comparison of Prescribing Practices with Direct Acting Oral Anticoagulant Protocols

BACKGROUND

The goal of anticoagulation management programs is to prevent thrombosis while minimizing the risks of hemorrhage. Direct acting oral anticoagulants (DOACs) selectively inhibit coagulation proteins to inhibit thrombosis. Previous studies suggest patient monitoring and education provided through anticoagulation services enhance adherence and decrease adverse outcomes in patients receiving DOAC therapy.

OBJECTIVE

The objectives of this study were to describe DOAC prescribing adherence to anticoagulation service protocols and to observe whether enrollment in an anticoagulation service resulted in greater prescribing adherence to DOAC protocols.

METHODS

A retrospective cohort study evaluated all initial prescriptions of apixaban, dabigatran, and rivaroxaban at Marshfield Clinic from 19 October 2010 to 21 August 2014. Three algorithms analyzed patient and prescription data extracted from the organization's electronic health record and classified prescriptions as per protocol or not per protocol. The algorithms classified not per protocol prescriptions as off-label indication, renal impairment [estimated glomerular filtration rate (eGFR) <30 ml/min], hepatic impairment (rivaroxaban and apixaban), advanced age >74 years (dabigatran), dose too low, or dose too high. The analysis assessed whether enrollment in the Marshfield Clinic Anticoagulation Service DOAC monitoring process was associated with increased adherence to protocols.

RESULTS

In aggregate, 72% of apixaban prescriptions, 52% of dabigatran prescriptions, and 70% of rivaroxaban prescriptions were per protocol. Off-label indications and dosage too low were the most common not per protocol reasons for apixaban and rivaroxaban prescriptions. Age ≥75 years and off-label indication were the most common not per protocol reasons for dabigatran prescriptions. Enrollment in the anticoagulation service process was not associated with increased adherence to protocols.

CONCLUSION

A significant proportion of DOAC prescriptions did not adhere to protocol expectations. While enrollment in DOAC management through the Marshfield Clinic Anticoagulation Service was not associated with increased adherence to protocols, opportunities exist to optimize DOAC prescribing. Defining ideal DOAC management requires additional research.

Effectiveness and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Asian Patients With Atrial Fibrillation

BACKGROUND AND PURPOSE

There are limited real-world data comparing the effectiveness and safety of non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in Asians with nonvalvular atrial fibrillation. We aimed to compare the effectiveness and safety between NOACs and warfarin users in the Korean atrial fibrillation population, with particular focus on high-risk patients.

METHODS

Using the Korean National Health Insurance Service database, we analyzed the risk of ischemic stroke, intracranial hemorrhage (ICH) events, and all-cause death in NOAC users (n=11 611 total, n=5681 taking rivaroxaban, n=3741 taking dabigatran, and n=2189 taking apixaban) compared with propensity score-matched warfarin users (n=23 222) among patients with high-risk atrial fibrillation (CHA₂DS₂-VASc score ≥2) between 2014 and 2015.

RESULTS

NOAC treatment was associated with similar risk of ischemic stroke and lower risk of ICH and all-cause mortality compared with warfarin. All 3 NOACs were associated with a similar risk of ischemic stroke and a lower risk of ICH compared with warfarin. Dabigatran and apixaban were associated with a lower risk of total mortality and the composite net clinical outcome (ischemic stroke, ICH, and all-cause death) compared with warfarin, whereas this was nonsignificant for rivaroxaban. Among previously oral anticoagulant-naive patients (n=23 262), dabigatran and apixaban were superior to warfarin for ICH prevention, whereas rivaroxaban and warfarin were associated with similar risk of ICH.

CONCLUSIONS

In real-world practice among a high-risk Asian atrial fibrillation population, all 3 NOACs demonstrated similar risk of ischemic stroke and lower risk of ICH compared with warfarin. All-cause mortality was significantly lower only with dabigatran and apixaban.

Adherence and outcomes to direct oral anticoagulants among patients with atrial fibrillation: findings from the veterans health administration

Background

The direct oral anticoagulants (DOACs) reduce the risk of stroke in moderate to high-risk patients with non-valvular atrial fibrillation (AF). Yet, concerns remain regarding its routine use in real world practice. We sought to describe adherence patterns and the association between adherence and outcomes to the DOACs among outpatients with AF.

Methods

We performed a retrospective cohort study of patients in the VA Healthcare System who initiated pharmacotherapy with dabigatran, rivaroxaban, or apixaban between November 2010 and January 2015 for non-valvular AF with CHA₂DS₂-VASc score ≥ 2. Adherence was determined using pharmacy refill data and estimated by the proportion of days covered (PDC) over the first year of therapy. Clinical outcomes, including all-cause mortality and stroke, were measured at 6 months and used to assess measures of adherence for each DOAC.

Results

A total of 2882 patients were included. Most were prescribed dabigatran (72.7%), compared with rivaroxaban (19.8%) or apixaban (7.5%). The mean PDC was 0.84 ± 0.20 for dabigatran, 0.86 ± 0.18 for rivaroxaban, and 0.89 ± 0.14 for apixaban (p < 0.01). The proportion of non-adherent patients, PDC <0.80, was 27.6% for all and varied according DOAC. Lower adherence to dabigatran was associated with higher risk of mortality and stroke (HR 1.07; 1.03–1.12 per 0.10 decline in PDC).

Conclusions

In a real-world VA population being prescribed anticoagulation for AF, more than one quarter had sub-optimal adherence. Lower adherence was associated with a higher risk of mortality and stroke. Efforts identifying non-adherent patients, and targeted adherence interventions are needed to improve outcomes.

Once- versus twice-daily direct oral anticoagulants in non-valvular atrial fibrillation

INTRODUCTION

Direct oral anticoagulants (DOACs) have emerged as alternatives to vitamin K antagonists for the prevention of stroke in patients with non-valvular atrial fibrillation (NVAF). Four DOACs: dabigatran, rivaroxaban, apixaban and edoxaban, are currently available. In the absence of head-to-head clinical comparisons of DOACs, dosing regimen may influence drug choice. Areas covered: Edoxaban and rivaroxaban are administered once daily, dabigatran and apixaban twice daily. The selection of these dosage regimens is largely based on studies for the prevention or treatment of venous thromboembolism or acute coronary syndrome. Edoxaban is the only DOAC in which once and twice-daily regimens were compared in patients with NVAF; bleeding rates were higher in the twice-daily groups. Once-daily versus twice-daily regimens have a number of practical implications. Missing a once-daily dose would have a greater impact on anticoagulation. Some real world and retrospective studies found that a once-daily dosing regimen leads to better adherence and persistence to therapy, an important consideration for maintaining optimum anticoagulation. However, other studies have not found increased adherence among once daily regimens. Expert opinion: Prescription of DOACs should be tailored to the individual patient and dosing regimen is only one of the variables that should be taken into account.

Clinical implications, benefits and pitfalls of using and reversing non-vitamin K antagonist oral anticoagulants

INTRODUCTION

The use of non-Vitamin K antagonist oral anticoagulant (NOAC) drugs is increasingly common in clinical practice. As compared to vitamin K antagonists they are more straightforward to initiate, require no hematological monitoring and offer potentially more stable therapeutic indices. Concern has been raised with regard to their safety profiles particularly in the context of acute reversal in major bleeding. Further issues pertain to patient concordance. Areas covered: This review article aims to provide an overview of the current evidence relating to NOAC safety as well as the management of NOAC-related major bleeding with particular emphasis on reversal agents in use and in development following a selective literature review. Second, the effects of medication concordance and dosing regimens on NOAC efficacy will be considered. Expert commentary: The short half-lives and low overall bleeding risk of NOACs is likely to mean that specific reversal agents in development are infrequently required and costly with associated practicality issues with their use in clinical emergencies. Concern regarding patient concordance can be practicably addressed with appropriate medication, dosing regimen and patient selection and continuous education with active, informed patient involvement in the decision-making process.

Adherence with direct oral anticoagulants in nonvalvular atrial fibrillation new users and associated factors: a French nationwide cohort study

Purpose

Direct oral anticoagulants (DOACs) have been promoted in patients with nonvalvular atrial fibrillation (nv‐AF) as a more convenient alternative to vitamin K antagonists. We estimated 1‐year dabigatran and rivaroxaban adherence rates in nv‐AF patients and assessed associations between baseline patient characteristics and nonadherence.

Methods

This cohort study included OAC‐naive nv‐AF patients with no contraindications to OAC, who initiated dabigatran and rivaroxaban, using nationwide data from French national health care databases. One‐year adherence was defined by the proportion of days covered of 80% or more over a fixed 1‐year period after treatment initiation. Associations between nonadherence and baseline patient characteristics were assessed using multivariate logistic regression models.

Results

The population was composed of 11 141 dabigatran (women: 48%; mean age: 74 ± 10.7 y; ≥80 y: 34.9%) and 11 126 rivaroxaban (46.5%; 74 ± 10.9 y; 34.8%) new users. One‐year adherence was 53.3% in dabigatran‐treated and 59.9% in rivaroxaban‐treated patients, consistent with numerous subgroup analyses. A switch to vitamin K antagonist was observed in 14.5% of dabigatran and 11.7% of rivaroxaban patients; 10.2% and 5.9% of patients switched to another DOAC, respectively; and 4.3% of patients died in the 2 cohorts. In patients who did not die or switch during the follow‐up, 1‐year adherence was 69.6% in dabigatran‐treated and 72.3% in rivaroxaban‐treated patients. Having concomitant ischemic heart diseases was associated with an increased risk of nonadherence in the 2 cohorts.

Conclusion

In this real‐life study, 1‐year adherence to DOAC is poor in nv‐AF new users. Despite the introduction of DOAC, adherence to OACs may remain a significant challenge in AF patients.

Use of direct oral anticoagulants in patients with atrial fibrillation in Scotland: Applying a coherent framework to drug utilisation studies

PURPOSE

To report the use of direct oral anticoagulants (DOACs) for stroke prevention in patients with atrial fibrillation in Scotland and advocate the standardisation of drug utilisation research methods.

METHODS

Retrospective cohort study using linked administrative data. Patients included those with a diagnosis of atrial fibrillation (confirmed in hospital) who received a first prescription for a DOAC (dabigatran, rivaroxaban, or apixaban) from September 2011 to June 2014. Drug utilisation measures included discontinuation, persistence, and adherence.

RESULTS

A total of 5398 patients (mean CHA₂ DS₂ -VASc score 2.98 [SD 1.71], 89.7% with ≥5 concomitant medicines) were treated with DOACs for a median of 228 days (interquartile range 105-425). Of 35.6% who discontinued DOAC treatment, 11.0% switched to warfarin, and 48.3% reinitiated DOACs. Persistence after 12 and 18 months was 75.9% and 69.8%, respectively. Differences between individual DOACs were observed: Discontinuation rates ranged from 20.4% (apixaban) to 60.6% (dabigatran) and 12 months persistence from 60.1% (dabigatran) to 85.5% (apixaban). Adherence to treatment with all DOACs was good: Overall DOAC median medication refill adherence was 102.9% (interquartile range 88.9%-115.5%), and 82.3% of patients had a medication refill adherence > 80%.

CONCLUSIONS

In Scotland, adherence to DOAC treatment was good, and switching from DOAC to warfarin was low. However, discontinuation and persistence rates were variable-although treatment interruptions were often temporary. To decrease the inconsistencies in drug utilisation methods and facilitate meaningful study comparison, the use of a coherent framework-using a combination of discontinuation, persistence, and adherence-and the standardisation of measurements is advocated.

Patients' experiences of atrial fibrillation and non-vitamin K antagonist oral anticoagulants (NOACs), and their educational needs: A qualitative study

PURPOSE

Qualitative research on atrial fibrillation (AF) patient's experiences and perceptions of taking the non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention is limited. This study explores patients' experiences of dabigatran and their recommendations for development of educational materials.

PATIENTS AND METHODS

Semi-structured individual interviews with 8 warfarin-naive and 8 warfarin-experienced AF patients, using qualitative deductive thematic analysis.

RESULTS

The four main overarching themes included: understanding the diagnosis; reaching a treatment decision; challenges of living with OAC; and patient perceptions of treatment. Patients discussed their shock of diagnosis, and seeking information and support at that time. Narratives suggest patients preferred to be led by the doctor when making treatment decisions, and would often compare dabigatran to warfarin. Patients reported side-effects and challenges with both treatment options, and discussed their beliefs surrounding medications, including misconceptions. In addition to the original framework, two further themes were added: challenges of living with AF, and patient recommendations. Generally patients found AF symptoms distressing, which impacted their quality of life. Patient recommendations included the content and delivery of educational materials and development of tools to help with their understanding of AF and anticoagulation, as well as treatment adherence and anxiety surrounding symptoms and side effects.

CONCLUSION

Patient recommendations emphasised the need for interventions to relieve anxiety surrounding the diagnosis and possible treatment side effects. Tailored 'disease-specific' support is essential to ensure efficacious treatment. This qualitative study highlights the need for patient involvement in the development of educational materials and resources for patients commencing treatment with NOACs.

New frontiers in anticoagulation: non vitamin-K oral anticoagulants in stroke prevention

INTRODUCTION

Non vitamin-K oral anticoagulants (NOACs) are direct and specific inhibitors of the coagulation factors IIa (dabigatran) and Xa (apixaban, rivaroxaban, edoxaban) which share many pharmacokinetic properties. However, indications are lacking regarding the use of NOACs during thrombolysis, surgery and bleeding events. Areas covered: In this paper, the authors retrospectively analyzed the relevant literature on the NOACs using the PubMed and Google Scholar databases. Expert commentary: Although warfarin is effective in cardioembolic stroke prevention, easier handling and more favorable risk-benefit profile often render NOACs a more preferable therapy choice for neurologists. New evidences have suggested their use in treatment of elderly people, in patients with renal insufficiency or with antiphospholipid antibody syndrome. In addition, the use of antidotes, which rapidly reverse the anticoagulant effect of the NOACs, could be useful in bleeding, during emergency procedures, or in case of overdose.

Therapeutic compliance with rivaroxaban in preventing stroke in patients with non-valvular atrial fibrillation: CUMRIVAFA study

OBJECTIVE

To assess compliance with treatment with rivaroxaban in patients with non-valvular atrial fibrillation.

METHODS

Prospective, longitudinal, multicenter study, developed in 160 Spanish primary or specialized care centers. We included 412 patients treated with rivaroxaban, prescribed for stroke prevention. Three visits were conducted: baseline, 6 and 12 months. Compliance was measured by using electronic monitors (MEMSs) that use a digital record in the form of a microchip in the lid of the drug container that automatically controls its opening and registers the time and date of the opening. We calculated the average compliance percentage (CP), global and daily compliance. We considered compliance to be when CP was 80-100%.

RESULTS

Three hundred and seventy patients ended the study (mean age 75.19, SD: 7.5 years). Global compliance was 84.1% (CI = 79.21-88.99%) and 80.3% (CI = 74.98-85.62%) after 6 and 12 months respectively. Daily compliance was 83.5% (CI = 78.53-88.57%) and 80% (CI = 74.65-85.35%) at 6 and 12 months. Significant differences in the CP between 6 and 12 months were observed. Global CP was 90.77% after 6 months and 89.65% at the end of the study. Daily CP was 90.14% and 87.66% at 6 and 12 months. There were significant CP differences between 6 and 12 months. Non-compliance was associated with a higher number of concomitant diseases, number of drugs taken and weight.

CONCLUSIONS

The percentage of compliance with rivaroxaban was high. A profile of variables that need to be modified in current medical practice, associated with non-compliance, was detected.

Adherence to oral anticoagulant therapy in patients with atrial fibrillation. Focus on non-vitamin K antagonist oral anticoagulants

Oral anticoagulation is pivotal in the management of thromboembolic risk in non-valvular atrial fibrillation (NVAF) patients. Effective anticoagulation is important to avoid major adverse events and medication adherence is central to achieve good anticoagulation control. Non-vitamin K antagonist oral anticoagulants (NOACs) are as effective and safe as vitamin K antagonist (VKAs) in NVAF patients. Due to the absence of routine anticoagulation monitoring with NOACs treatment, concerns have been raised about patient's adherence to NOACs and real-life data demonstrates variability in adherence and persistence. A multi-level approach, including patients' preferences, factors determining physicians' prescribing habits and healthcare system infrastructure and support, is warranted to improve initiation and adherence of anticoagulants. Adherence to NOACs is paramount to achieve a clinical benefit. Implementation of educational programs and easy-to-use tools to identify patients most likely to be non-adherent to NOACs, are central issues in improving the quality of NVAF anticoagulation management.

Improved persistence with non-vitamin-K oral anticoagulants compared with warfarin in patients with atrial fibrillation: recent Australian experience

OBJECTIVE

Long-term anticoagulant therapy in patients with non-valvular atrial fibrillation (AF) is essential to prevent thromboembolic complications, especially ischemic stroke, but treatment persistence with warfarin is poor. This study examines Australian nationwide persistence in AF patients using a non-vitamin-K oral anticoagulant (NOAC) drug.

RESEARCH DESIGN AND METHODS

We assessed national Pharmaceutical Benefit Scheme records November-December 2013 through March 2015 for prescription of NOAC drugs in a 10% random sample of long-term concession card holders. An historical comparison was made with patients prescribed warfarin in 2008. Key outcome measures were (i) the proportion not filling first repeat prescription and (ii) discontinuation within 12 months.

RESULTS

A total of 1471 patients with AF were new users of a NOAC drug (228 apixaban, 645 dabigatran, 598 rivaroxaban) and 1348 were new users of warfarin. Mean age on a NOAC was 76 years (58% male), on warfarin 74 years (54% male). Only 9% (95% CI 7-10) failed to collect the first repeat prescription on a NOAC, 30% (27-32) discontinued within 12 months; corresponding proportions on warfarin were 14% (12-16) and 62% (60-65). In a regression model adjusted for age, gender, heart failure, hypertension and diabetes, warfarin-treated patients were 2.5 times more likely to discontinue over 12 months than those who were NOAC treated (hazard ratio =2.47 [95% CI 2.19-2.79]).

CONCLUSIONS

Persistence with NOAC drugs in patients with AF appears to be superior to warfarin. If continued long-term, this alone will be of clinical importance in the prevention of stroke and death.

A Summary of the Literature Evaluating Adherence and Persistence with Oral Anticoagulants in Atrial Fibrillation

Atrial fibrillation (AF) is a growing public health concern and remains an independent risk factor for ischemic stroke. Warfarin, a commonly used oral anticoagulant, is associated with a 60-70 % relative reduction in stroke risk and a reduction in mortality of 26 %. However, warfarin has several limitations, including a narrow therapeutic window, variable dose response, multiple interactions with other drugs and concurrent illnesses, and the need for frequent laboratory monitoring. In recent years, the direct acting oral anticoagulants (DOACs), including dabigatran, rivaroxaban, apixaban and edoxaban, have been developed to overcome the limitations of warfarin therapy. These treatment strategies are either comparable or superior to warfarin in stroke prevention in AF. Despite the documented effectiveness of oral anticoagulants in AF, patients may not derive optimal benefit if they fail to adhere or fail to continue with their medication. This may lead to treatment failure, increased hospitalization and mortality. This review summarizes the literature regarding adherence and persistence (or discontinuation) rates with oral anticoagulants in the management of AF; the impact of non-adherence and non-persistence on treatment outcomes; and the effectiveness of strategies to improve adherence and persistence with oral anticoagulant therapy.