Comparison of Adherence to Rivaroxaban Versus Apixaban Among Patients With Atrial Fibrillation

Anticoagulant Treatment Adherence and Persistence in German Patients with Atrial Fibrillation

INTRODUCTION

Treatment adherence and persistence impact the effectiveness of edoxaban for the prevention of thromboembolism in patients with atrial fibrillation (AF). The objective of this analysis was to assess adherence and persistence of edoxaban vs. other non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs).

METHODS

Utilizing a German claims database, adults with AF with the first pharmacy claim identified for edoxaban, apixaban, dabigatran, rivaroxaban, or VKAs from January 2013 to December 2017 were included in a propensity score-matched analysis. The first pharmacy claim was the index claim. Adherence (i.e., proportion of days covered [PDC]) and persistence (proportion of patients who continued therapy) were compared between edoxaban and other therapies. Patients receiving once-daily (QD) vs. twice-daily (BID) NOAC were also analyzed.

RESULTS

Overall, 21,038 patients were included (1236 edoxaban, 6053 apixaban, 1306 dabigatran, 7013 rivaroxaban, and 5430 VKA). After matching, baseline characteristics were well balanced across cohorts. Adherence was significantly higher for edoxaban vs. apixaban, dabigatran, and VKAs (all P < 0.0001). Significantly more edoxaban patients continued therapy vs. rivaroxaban (P = 0.0153), dabigatran (P < 0.0001), and VKAs (P < 0.0001). Time to discontinuation was significantly longer for edoxaban vs. dabigatran, rivaroxaban, and VKAs (all P < 0.0001). More patients receiving NOACs QD had a PDC ≥ 0.8 compared with those receiving NOACs BID (65.3 vs. 49.6%, respectively; P < 0.05); persistence rates were comparable between QD and BID groups.

CONCLUSIONS

Patients with AF receiving edoxaban had significantly higher adherence and persistence compared with those receiving VKAs. This trend was also seen in NOAC QD regimens vs. NOAC BID regimens for adherence. These results provide insight into how adherence and persistence may contribute to the effectiveness of edoxaban for stroke prevention in patients with AF in Germany.

Development and verification of a physiologically based pharmacokinetic model of dronedarone and its active metabolite N-desbutyldronedarone: Application to prospective simulation of complex drug-drug interaction with rivaroxaban

AIMS

Despite potential enzyme- and transporter-mediated drug-drug interactions (DDIs) between dronedarone and rivaroxaban in atrial fibrillation (AF) patients, pharmacokinetic/pharmacodynamic data remain limited to guide clinical practice. We aimed to develop, verify and validate a physiologically based pharmacokinetic (PBPK) model of dronedarone and its major metabolite, N-desbutyldronedarone (NDBD), to prospectively interrogate this clinically relevant DDI in healthy and mild renal impairment populations.

METHODS

The middle-out development of our PBPK model combined literature-derived or in-house in vitro data, predicted in silico data and in vivo clinical data. Model verification was performed for intravenous and oral (single and multiple) dosing regimens. Model validation for the accurate prediction of cytochrome P450 (CYP)3A4- and P-glycoprotein-mediated DDI utilized simvastatin and digoxin as respective victim drugs. Rivaroxaban-specific inhibitory parameters of dronedarone and/or NDBD against CYP3A4, CYP2J2, OAT3 and P-glycoprotein were incorporated into the PBPK-DDI model for prospective dronedarone-rivaroxaban DDI simulation.

RESULTS

Dronedarone and NDBD PK following clinically relevant doses of 400 mg dronedarone across single and multiple oral dosing were accurately simulated by incorporating effect of auto-inactivation on dose nonlinearities. Following successful model validation, nondose-adjusted rivaroxaban-dronedarone DDI in healthy and mild renal impairment populations revealed simulated rivaroxaban area under the plasma concentration-time curve up to 24 h fold change greater than dose exposure equivalence (0.70-1.43) at 1.65 and 1.84, respectively. Correspondingly, respective major bleeding risk was 4.24 and 4.70% compared with threshold of 4.5% representing contraindicated rivaroxaban-ketoconazole DDI.

CONCLUSION

Our PBPK-DDI model predicted clinically significant dronedarone-rivaroxaban DDI in both healthy and mild renal impairment subjects. Greater benefit vs. risk could be achieved with rivaroxaban dose reductions to at least 15 mg in mild renal impairment subjects on concomitant dronedarone and rivaroxaban.

Adherence to rivaroxaban for the treatment of venous thromboembolism-Results from the FIRST registry

BACKGROUND

Medication nonadherence can result in poor clinical outcomes and significant costs to health care providers. When treating venous thromboembolism (VTE), subtherapeutic anticoagulation may contribute to complications such as recurrent VTE or postthrombotic syndrome.

OBJECTIVES

To describe the extent, reasons for, and predictors of nonadherence to rivaroxaban for the treatment of VTE in clinical practice in the United Kingdom reported by participants of the FIRST registry.

PATIENTS/METHODS

The FIRST registry was an observational, multicenter registry reporting on the use of rivaroxaban in routine clinical practice. FIRST registry participants completed an adherence screening questionnaire during their treatment and follow-up.

RESULTS

In total, 1028 participants completed 1660 questionnaires over 2 years. One hundred thirteen of 1028 (11%) reported nonadherence at 28 days (interquartile range, 21-45). Reasons given for nonadherence at 1 month were forgetfulness (8.6% vs 74.7%; P < .001), carelessness (2.7% vs 27.3%; P < .001) or a change in routine (7.4% vs 25.5%; P < .001) reported by adherent and nonadherent participants, respectively. Older age (10-year increments) was the strongest predictor of good adherence (adjusted odds ratio, 1.21; 95% confidence interval, 1.06-1.39; 1 = adherent).

CONCLUSIONS

Overall adherence to rivaroxaban was high, and most nonadherence was unintentional. Identification of those at risk of nonadherence may reduce the risk of VTE recurrence and long-term complications.

Antiplatelet and anticoagulant agents have minimal impact on traumatic brain injury incidence, surgery, and mortality in geriatric ground level falls: A multi-institutional analysis of 33,710 patients

BACKGROUND

Falls are the leading cause of traumatic brain injury (TBI) and TBI-related deaths for older persons (age, ≥65 years). Antiplatelet and/or anticoagulant therapy (antithrombotics [ATs]) is generally felt to increase this risk, but the literature is inconsistent. The purpose of this study was to determine the impact of AT use on the rate, severity, and outcomes of TBI in older patients following ground level falls.

METHODS

Ground level fall patients from 90 hospitals' trauma registries were selected. Patients were excluded if younger than 65 years or had an Abbreviated Injury Scale score of >2 in a region other than head. Electronic medical record data for preinjury AT therapy were obtained. Patients were grouped by regimen for no AT, single, or multiple agents. Groups were compared on rates of diagnosed TBI, TBI surgery, and mortality.

RESULTS

There were 33,710 patients (35% male; mean age, 80.5 years; mean Glasgow Coma Scale, 14.6), with 47.6% on single or combination AT therapy. The proportion of patients with TBI diagnoses did not differ between those on no AT (21.25%) versus AT (21.61%; p = 0.418). Apixaban (15.7%; p < 0.001) and rivaroxaban (13.19%; p = 0.011) were associated with lower rates of TBI, and acetylsalicylic acid-clopidogrel was associated with a higher TBI rate (24.34%; p = 0.002) versus no AT. acetylsalicylic acid-clopidogrel was associated with a higher cranial surgery rate (2.9%; p = 0.006) versus no AT (1.96%), but surgery rates were similar for all other regimens. No regimen was associated with higher mortality.

CONCLUSION

In this large multicenter study, the intake of ATs in older patients with ground level falls was associated with inconsistent effects on risk of TBI and no significant increases in mortality, indicating that AT use may have negligible impact on patient clinical management. A large, confirmatory, prospective study is needed because the commonly held belief that ATs uniformly increase the risk of traumatic intracranial bleeding and mortality is not supported.

LEVEL OF EVIDENCE

Therapeutic/care management, level II.

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.

Real-World Adherence and Persistence to Direct Oral Anticoagulants in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND

Stroke reduction with direct oral anticoagulants (DOACs) in atrial fibrillation (AF) is dependent on adherence and persistence in the real-world setting. Individual study estimates of DOAC adherence/persistence rates have been discordant. Our aims were to characterize real-world observational evidence for DOAC adherence/persistence and evaluate associated clinical outcomes in patients with AF.

METHODS AND RESULTS

PubMed, EMBASE, and CINAHL were searched from inception to June 2018. Observational studies that reported real-world DOAC adherence/persistence in patients with AF were included. Study quality was assessed using the Newcastle-Ottawa Scale. Meta-analyses for pooled estimates were performed using DerSimonian and Laird random-effects models. Outcomes included DOAC mean proportion of days covered or medication possession ratio, proportion of good adherence (proportion of days covered/medication possession ratio ≥80%), persistence, DOAC versus vitamin K antagonists persistence, and clinical outcomes associated with nonadherence/nonpersistence. Forty-eight observational studies with 594 784 unique patients with AF (59% male; mean age 71 years) were included. The overall pooled mean proportion of days covered/medication possession ratio was 77% (95% CI, 75%-80%), proportion of patients with good adherence was 66% (95% CI, 63%-70%), and proportion persistent was 69% (95% CI, 65%-72%). The pooled proportion of patients with good adherence was 71% (95% CI, 64%-78%) for apixaban, 60% (95% CI, 52%-68%) for dabigatran, and 70% (95% CI, 64%-75%) for rivaroxaban. Similar patterns were found for pooled persistence by agent. The pooled persistence was higher with DOACs than vitamin K antagonists (odds ratio, 1.44 [95% CI, 1.12-.86]). DOAC nonadherence was associated with an increased risk of stroke (hazard ratio, 1.39 [95% CI, 1.06-1.81]).

CONCLUSIONS

Suboptimal adherence and persistence to DOACs was common in patients with AF, with 1 in 3 patients adhering to their DOAC <80% of the time, which was associated with poor clinical outcomes in nonadherent patients. Although it is convenient that DOACs do not require laboratory monitoring, greater effort in monitoring for and interventions to prevent nonadherence may be necessary to optimize stroke prevention. Increased clinician awareness of DOAC nonadherence may help identify at-risk patients.

Direct Oral Anticoagulants in Patients With Nonvalvular Atrial Fibrillation: Update and Periprocedural Management

Vitamin K antagonists (eg, warfarin) have been the standard of care for stroke prophylaxis in atrial fibrillation. The direct oral anticoagulants dabigatran (direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (direct factor Xa inhibitors) are as efficacious as and in some instances superior to vitamin K antagonists in the prevention of stroke, systemic embolism, and major bleeding compared with warfarin for nonvalvular atrial fibrillation. Benefits of direct oral anticoagulants include a rapid onset of therapeutic effect, fixed dose-response relationships without the need for routine monitoring, a short half-life, and infrequent need for periprocedural bridging with a parenteral agent. However, direct oral anticoagulants differ in subsets of patients. Critical care and advanced practice nurses must understand these differences, prescribing considerations, drug aherence interventions, drug-drug interactions, and periprocedural management. This article presents an update and review of direct oral antigcoagulants based on the latest national guidelines.

The 2018 European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

The current manuscript is the second update of the original Practical Guide, published in 2013 [Heidbuchel et al. European Heart Rhythm Association Practical Guide on the use of new oral anticoagulants in patients with non-valvular atrial fibrillation. Europace 2013;15:625-651; Heidbuchel et al. Updated European Heart Rhythm Association Practical Guide on the use of non-vitamin K antagonist anticoagulants in patients with non-valvular atrial fibrillation. Europace 2015;17:1467-1507]. Non-vitamin K antagonist oral anticoagulants (NOACs) are an alternative for vitamin K antagonists (VKAs) to prevent stroke in patients with atrial fibrillation (AF) and have emerged as the preferred choice, particularly in patients newly started on anticoagulation. Both physicians and patients are becoming more accustomed to the use of these drugs in clinical practice. However, many unresolved questions on how to optimally use these agents in specific clinical situations remain. The European Heart Rhythm Association (EHRA) set out to coordinate a unified way of informing physicians on the use of the different NOACs. A writing group identified 20 topics of concrete clinical scenarios for which practical answers were formulated, based on available evidence. The 20 topics are as follows i.e., (1) Eligibility for NOACs; (2) Practical start-up and follow-up scheme for patients on NOACs; (3) Ensuring adherence to prescribed oral anticoagulant intake; (4) Switching between anticoagulant regimens; (5) Pharmacokinetics and drug-drug interactions of NOACs; (6) NOACs in patients with chronic kidney or advanced liver disease; (7) How to measure the anticoagulant effect of NOACs; (8) NOAC plasma level measurement: rare indications, precautions, and potential pitfalls; (9) How to deal with dosing errors; (10) What to do if there is a (suspected) overdose without bleeding, or a clotting test is indicating a potential risk of bleeding; (11) Management of bleeding under NOAC therapy; (12) Patients undergoing a planned invasive procedure, surgery or ablation; (13) Patients requiring an urgent surgical intervention; (14) Patients with AF and coronary artery disease; (15) Avoiding confusion with NOAC dosing across indications; (16) Cardioversion in a NOAC-treated patient; (17) AF patients presenting with acute stroke while on NOACs; (18) NOACs in special situations; (19) Anticoagulation in AF patients with a malignancy; and (20) Optimizing dose adjustments of VKA. Additional information and downloads of the text and anticoagulation cards in different languages can be found on an EHRA website (www.NOACforAF.eu).

Improved Dosing and Administration of Rivaroxaban when Prescribed by a Cardiologist

Rivaroxaban is a direct oral anticoagulant (DOAC) indicated to reduce risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF). A discrepancy exists between the recommended dosage and real-world use of DOACs, especially rivaroxaban, thus putting patients at risk of thromboembolic events.

METHODS

This retrospective study assessed real-world prescribing and patient adherence to dietary requirements during use of rivaroxaban in 116 patients with AF. Associations between prescriber specialty and the correct dosing and administration were assessed using the Chi-Square test.

RESULTS

Most rivaroxaban prescriptions were ordered by cardiologists (50.9%). Sixty-nine patients (59.5%) were taking the right dose at the correct time with an adequate meal. Of the 47 (40.5%) taking rivaroxaban incorrectly, 39 (33.6%) had not been administered an adequate meal and eight (6.9%) were not prescribed the correct dose. Compared with other prescribers, patients were most likely to be taking the correct dose and administration when prescribed by cardiologists (72.9% versus 45.6%; p=0.003). Patients were least likely to be taking the correct dose and administration when prescribed by primary care providers (44.4% versus 69.0%; p=0.009). This difference was driven by patients who did not take the treatment with an adequate meal.

CONCLUSION

Inappropriate prescribing, administration and non-adherence to DOACs can have devastating consequences. This highlights the importance of formal systematic education of patients prescribed DOACs across the whole health system. Future studies are warranted to explore the impact of non-adherence to rivaroxaban dietary requirements on clinical outcomes.

Predictors of self-reported adherence to direct oral anticoagulation in a population of elderly men and women with non-valvular atrial fibrillation

There is a general lack of studies evaluating medication adherence with self-report scales for elderly patients in treatment with direct oral anticoagulants (DOACs). The aim of the study was to assess the degree of adherence to DOAC therapy in a population of elderly outpatients aged 65 years or older affected by non-valvular atrial fibrillation (NVAF), using the 4-item Morisky Medication Adherence Scale, and to identify potential factors, including the geriatric multidimensional evaluation, which can affect adherence in the study population. A total of 103 subjects, anticoagulated with DOACs for NVAF in primary or secondary prevention, were eligible; 76 showed adequate adhesion to anticoagulant therapy, while 27 showed inadequate adherence. Participants underwent biochemical assessment and Morisky Scale, Instrumental Activities of Daily Living, CHA2DS2-VASc, HAS-BLED, mental status and nutritional evaluations were performed. 2% of subjects assumed Dabigatran at low dose, while 7.8% at standard dose, 9.7% assumed low-dose of Rivaroxaban and 30.1% at standard dose, 6.8% assumed Apixaban at low dose and 39.7% at standard dose, and finally 1% assumed Edoxaban at low dose and 2.9% at standard dose. Most subjects took the DOACs without help (80.6%), while 16 subjects were helped by a family member (15.5%) and 4 were assisted by a caregiver (3.9%). Binary logistic regression considered inappropriate adherence as a dependent variable, while age, male sex, polypharmacotherapy, cognitive decay, caregiver help for therapy assumption, duration of DOAC therapy and double daily administration were considered as independent variables. The double daily administration was an independent factor, determining inappropriate adherence with an OR of 2.88 (p = 0.048, CI 1.003-8.286).

Real-world adherence to oral anticoagulants in atrial fibrillation patients: a study protocol for a systematic review and meta-analysis

INTRODUCTION

Atrial fibrillation (AF) is one of the leading causes of cerebrovascular mortality and morbidity. Oral anticoagulants (OACs) have been shown to reduce the incidence of cardioembolic stroke in patients with AF, adherence to treatment being an essential element for their effectiveness. Since the release of the first non-vitamin K antagonist oral anticoagulant, several observational studies have been carried out to estimate OAC adherence in the real world using pharmacy claim databases or AF registers. This systematic review aims to describe secondary adherence to OACs, to compare adherence between OACs and to analyse potential biases in OAC secondary adherence studies using databases.

METHODS AND ANALYSIS

We searched on PubMed, SCOPUS and Web of Science databases (completed in 26 September 2018) to identify longitudinal observational studies reporting days' supply adherence measures with OAC in patients with AF from refill databases or AF registers. The main study endpoint will be the percentage of patients exceeding the 80% threshold in proportion of days covered or the medication possession ratio. Two reviewers will independently screen potential studies and will extract data in a structured format. A random-effects meta-analysis will be carried out to pool study estimates. The risk of bias will be assessed using the Newcastle-Ottawa Scale for observational studies and we will also assess some study characteristics that could affect days' supply adherence estimates.

ETHICS AND DISSEMINATION

This systematic review using published aggregated data does not require ethics approval according to Spanish law and international regulations. The final results will be published in a peer-review journal and different social stakeholders, non-academic audiences and patients will be incorporated into the diffusion activities.

PROSPERO REGISTRATION NUMBER

CRD42018095646.

Estimating Adherence Based on Prescription or Dispensation Information: Impact on Thresholds and Outcomes. A Real-World Study With Atrial Fibrillation Patients Treated With Oral Anticoagulants in Spain

Objective: To estimate drug exposure, Proportion of Days Covered (PDC) and percentage of patients with PDC ≥ 80% from a cohort of atrial fibrillation patients initiating oral anticoagulant (OAC) treatment. We employed three different approaches to estimate PDC, using either data from prescription and dispensing (PD cohort) or two common designs based on dispensing information only, requiring at least one (D1) or at least two (D2) refills for inclusion in the cohorts. Finally, we assessed the impact of adherence on health outcomes according to each method. Methods: Population-based retrospective cohort of all patients with Non Valvular Atrial Fibrillation (NVAF), who were newly prescribed acenocoumarol, apixaban, dabigatran or rivaroxaban from November 2011 to December 2015 in the region of Valencia (Spain). Patients were followed for 12 months to assess adherence using three different approaches (PD, D1 and D2 cohorts). To analyze the relationship between adherence (PDC ≥ 80) defined according to each method of calculation and health outcomes (death for any cause, stroke or bleeding) Cox regression models were used. For the identification of clinical events patients were followed from the end of the adherence assessment period to the end of the available follow-up period. Results: PD cohort included all patients with an OAC prescription (n = 38,802), D1 cohort excluded fully non-adherent patients (n = 265) and D2 cohort also excluded patients without two refills separated by 180 days (n = 2,614). PDC ≥ 80% ranged from 94% in the PD cohort to 75% in the D1 cohort. Drug exposure among adherent (PDC ≥ 80%) and non-adherent (PDC < 80%) patients was different between cohorts. In adjusted analysis, high adherence was associated with a reduced risk of death [Hazard Ratio (HR): from 0.82 to 0.86] and (except in the PD cohort) the risk for ischemic stroke (HR: from 0.61 to 0.64) without increasing the risk of bleeding. Conclusion: Common approaches to assess adherence using measures based on days' supply exclude groups of non-adherent patients and, also, misattribute periods of doctors' discontinuation to patient non-adherence, misestimating adherence overall. Physician-initiated discontinuation is a major contributor to reduced OAC exposure. When using the PDC80 threshold, very different groups of patients may be classified as adherent or non-adherent depending on the method used for the calculation of days' supply measures. High adherence and high exposure to OAC treatment in NVAF patients is associated with better health outcomes.

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.

Role of rivaroxaban in the management of atrial fibrillation: insights from clinical practice

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and it leads to significant morbidity and mortality, predominantly from ischemic stroke. Vitamin K antagonists, mainly warfarin, have been used for decades to prevent ischemic stroke in AF, but their use is limited due to interactions with food and other drugs, as well as the requirement for regular monitoring of the international normalized ratio. Rivaroxaban, a direct factor Xa inhibitor and the most commonly used non-vitamin K oral anticoagulant, avoids many of these challenges and is being prescribed with increasing frequency for stroke prevention in non-valvular AF. Randomized controlled trial (RCT) data from the ROCKET-AF(Rivaroxaban once daily oral direct Factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and embolism trial in atrial fibrillation) trial have shown rivaroxaban to be non-inferior to warfarin in preventing ischemic stroke and systemic embolism and to have comparable overall bleeding rates. Applicability of the RCT data to real-world practice can sometimes be limited by complex clinical scenarios or multiple comorbidities not adequately represented in the trials. Available real-world evidence in non-valvular AF patients with comorbidities - including renal impairment, acute coronary syndrome, diabetes mellitus, malignancy, or old age - supports the use of rivaroxaban as safe and effective in preventing ischemic stroke in these subgroups, though with some important considerations required to reduce bleeding risk. Patient perspectives on rivaroxaban use are also considered. Real-world evidence indicates superior rates of drug adherence with rivaroxaban when compared with vitamin K antagonists and with alternative non-vitamin K oral anticoagulants - perhaps, in part, due to its once-daily dosing regimen. Furthermore, self-reported quality of life scores are highest among patients compliant with rivaroxaban therapy. The generally high levels of patient satisfaction with rivaroxaban therapy contribute to overall favorable clinical outcomes.

Pharmacological and Non-pharmacological Treatments for Stroke Prevention in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is associated with significant risk of stroke and other thromboembolic events, which can be effectively prevented using oral anticoagulation (OAC) with either vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, or edoxaban. Until recently, VKAs were the only available means for OAC treatment. NOACs had similar efficacy and were safer than or as safe as warfarin with respect to reduced rates of hemorrhagic stroke or other intracranial bleeding in the respective pivotal randomized clinical trials (RCTs) of stroke prevention in non-valvular AF patients. Increasing “real-world” evidence on NOACs broadly confirms the results of the RCTs. However, individual patient characteristics including renal function, age, or prior bleeding should be taken into account when choosing the OAC with best risk–benefit profile. In patients ineligible for OACs, surgical or interventional stroke prevention strategies should be considered. In patients undergoing cardiac surgery for other reasons, the left atrial appendage excision, ligation, or amputation may be the best option. Importantly, residual stumps or insufficient ligation may result in even higher stroke risk than without intervention. Percutaneous left atrial appendage occlusion, although requiring minimally invasive access, failed to demonstrate reduced ischemic stroke events compared to warfarin. In this review article, we summarize current treatment options and discuss the strengths and major limitations of the therapies for stroke risk reduction in patients with AF.

Medium- to long-term persistence with non-vitamin-K oral anticoagulants in patients with atrial fibrillation: Australian experience

OBJECTIVE

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

RESEARCH DESIGN AND METHODS

We assessed national Pharmaceutical Benefit Scheme records December 2013 through September 2016 for initial prescription of a NOAC in a 10% random sample of concessional patients. Key outcome measures were: (a) proportions filling first repeat prescription, (b) proportions persisting with NOAC over 12 and 30 months and (c) proportions switching to another NOAC or warfarin.

RESULTS

A total of 8656 patients with AF initiated a NOAC (3352 apixaban, 1340 dabigatran, 3964 rivaroxaban). Mean age was 77 years, 53% male; 91% collected the first repeat prescription for any NOAC, 70% and 57% collected any NOAC or subsequent warfarin prescription over 12 months and 30 months respectively; 8.9% had switched to warfarin. The proportions switching from apixaban, dabigatran and rivaroxaban to a different NOAC were 14%, 31% and 17% respectively. In a regression model adjusting for age, gender and comorbidity, apixaban-initiated patients over 30 months were 28% more likely to persist with any anticoagulant therapy compared with dabigatran-initiated patients (hazard ratio [95% CI] 1.28 [1.16-1.42]) and 15% more likely to persist compared with rivaroxaban-initiated (1.15 [1.06-1.24]). Rivaroxaban-initiated patients were 12% more likely to persist compared with dabigatran-initiated patients (1.12 [1.02-1.24]).

CONCLUSIONS

Long-term persistence with anticoagulation in patients with AF remains a concern, even with NOACs. Patients initiated to apixaban appear to experience better medium-term persistence compared with rivaroxaban or dabigatran.