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

Comparative effectiveness and safety of direct oral anticoagulants and warfarin in atrial fibrillation patients with dementia

INTRODUCTION

Developing an effective stroke prevention strategy is crucial for elderly atrial fibrillation (AF) patients with dementia. This is due to the limited and inconsistent evidence available on this topic. In this nationwide, population-based cohort study, we aim to compare the effectiveness and safety of direct oral anticoagulants (DOACs) and warfarin in AF patients with dementia.

PATIENTS AND METHODS

We identified AF patients with dementia, aged 50 years or older, from Taiwan's National Health Insurance Research Database between 2010 and 2019. The primary outcome was a composite of hospitalizations due to ischemic stroke, acute myocardial infarction, intracranial hemorrhage, or major bleeding, as well as all-cause mortality. We used 1:1 propensity score matching and Cox proportional hazard models to adjust for confounding factors when comparing outcomes between warfarin and DOAC (apixaban, dabigatran, edoxaban, or rivaroxaban) users or warfarin and each individual DOAC.

RESULTS

There were 2952 patients in the DOAC-warfarin matched cohort. The apixaban-, dabigatran-, edoxaban-, and rivaroxaban-warfarin matched cohorts had 2346, 2554, 1684, and 2938 patients, respectively. The DOAC group, when compared to warfarin, was associated with a lower risk of both the composite outcome (hazard ratio (HR), 0.81; 95% confidence interval (CI) 0.69-0.95) and ischemic stroke (HR 0.65; 95% CI 0.48-0.87). Apixaban (HR 0.79; 95% CI 0.66-0.94), dabigatran (HR 0.64; 95% CI 0.53-0.77), and rivaroxaban (HR 0.82; 95% CI 0.70-0.97) were also associated with a lower risk of the composite outcome.

DISCUSSION AND CONCLUSION

Compared to warfarin, DOACs, whether as a group or apixaban, dabigatran, or rivaroxaban individually, were associated with a reduced risk of the composite outcome in elderly patients with concurrent AF and dementia.

Comparison of Apixaban, Rivaroxaban, Dabigatran, and Vitamin K Antagonists in Patients With Atrial Fibrillation and Liver Disease: A Network Meta-Analysis

Atrial fibrillation (AF) patients with liver disease present unique challenges in anticoagulation management due to increased risks of both thromboembolism and bleeding. This network meta-analysis aimed to compare the efficacy and safety of direct oral anticoagulants (DOACs), apixaban, rivaroxaban, and dabigatran, with vitamin K antagonists (VKAs) in this specific patient population. We conducted a comprehensive literature search across multiple databases, identifying seven studies (six observational and one randomized controlled trial) that met our inclusion criteria. The primary outcomes were the risk of stroke or systemic embolism (SE) and bleeding events. Our analysis revealed that all three DOACs demonstrated superior efficacy and safety profiles compared to VKAs. Apixaban showed the most favorable outcomes, with the highest probability of being the most effective in preventing both stroke/SE (RR: 0.51, 95% CI: 0.38-0.67) and bleeding events (RR: 0.54, 95% CI: 0.43-0.69). Rivaroxaban and dabigatran also significantly reduced the risk of these outcomes compared to VKAs but to a lesser extent than apixaban. Notably, rivaroxaban was associated with a slightly increased bleeding risk compared to apixaban (RR: 0.76, 95% CI: 0.58-0.99). The consistency of our network model was confirmed through both global and local tests. While these findings provide valuable guidance for clinicians, the study's limitations, including the predominance of observational data, highlight the need for large-scale randomized controlled trials. Future research should focus on clearly defined anticoagulant dosing regimens and comprehensive assessments of cirrhosis status to further optimize anticoagulation strategies in AF patients with liver disease.

The Role of Direct Oral Anticoagulants in the Treatment of Cancer-Associated Venous Thromboembolism: Review by Middle East and North African Experts

Venous thromboembolism is a leading cause of morbidity and mortality in patients with active cancer who require anticoagulation treatment. Choice of anticoagulant is based on careful balancing of the risks and benefits of available classes of treatment: vitamin K antagonists, low-molecular-weight heparin (LMWH), and direct oral anticoagulants (DOACs). Results from randomized controlled trials have shown the consistent efficacy of DOACs versus LMWH in the treatment of cancer-associated venous thromboembolism (VTE). However, increased major gastrointestinal bleeding was observed for edoxaban and rivaroxaban, but not apixaban, compared with LMWH dalteparin. Most guidelines recommend DOACs for the treatment of cancer-associated VTE in patients without gastrointestinal or genitourinary cancer, and with considerations for renal impairment and drug-drug interactions. These updates represent a major paradigm shift for clinicians in the Middle East and North Africa. The decision to prescribe a DOAC for a patient with cancer is not always straightforward, particularly in challenging subgroups of patients with an increased risk of bleeding. In patients with gastrointestinal malignancies who are at high risk of major gastrointestinal bleeds, apixaban may be the preferred DOAC; however, caution should be exercised if patients have upper or unresected lower gastrointestinal tumors. In patients with gastrointestinal malignancies and upper or unresected lower gastrointestinal tumors, LMWH may be preferred. Vitamin K antagonists should be used only when DOACs and LMWH are unavailable or unsuitable. In this review, we discuss the overall evidence for DOACs in the treatment of cancer-associated VTE and provide treatment suggestions for challenging subgroups of patients with cancer associated VTE.

Direct oral anticoagulants in trauma patients

PURPOSE OF REVIEW

Direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. Thus, trauma care providers are facing a steadily raising number of injured patients on DOACs.

RECENT FINDINGS

Despite a predictable pharmacokinetic profile, the resulting plasma levels of trauma patients upon admission and bleeding risks remain uncertain. Therefore, recent guidelines recommend the measurement of DOAC plasma concentrations in injured patients. Alternatively, DOAC specific visco-elastic tests assays can be applied to identify DOAC patients at bleeding risk.Bleeding complications in trauma patients on DOACs are generally higher compared to nonanticoagulated subjects, but comparable to vitamin K antagonists (VKAs). In particular, a traumatic brain injury does not carry an increased risk of intracranial bleeding due to a DOAK intake compared to VKAs. Current studies demonstrated that up to 14% of patients with a hip fracture are on DOACs prior to surgery. However, the majority can be operated safely within a 24h time window without an increased bleeding rate.Specific antagonists facilitate rapid reversal of patients on DOACs. Idarucizumab for dabigatran, and andexanet alfa for apixaban and rivaroxaban have been approved for life threatening bleeding. Alternatively, prothrombin complex concentrate can be used. Dialysis is a potential treatment option for dabigatran and haemoabsorption with special filters can be applied in patients on FXa-inhibitors.

SUMMARY

Current guidelines recommend the measurement of DOAC plasma levels in trauma patients. Compared to VKAs, DOACs do not carry a higher bleeding risk. DOAC specific antagonists facilitate the individual bleeding management.

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.

DOAC plasma concentration upon hospital admission in a cohort of trauma patients. An observational real-life study

PURPOSE

Due to a better safety profile, direct oral anticoagulants (DOACs) are increasingly prescribed for prevention of thromboembolic events. However, little is known about DOAC plasma concentrations in trauma patients upon hospital admission. Thus, we investigated the frequency and extent of DOAC possible over- and underdosing in trauma patients upon hospital admission.

METHODS

In this single-center retrospective study, DOAC plasma concentrations of adult trauma patients were analyzed with specific calibrated anti-IIa (dabigatran) and anti-Xa (apixaban, edoxaban and rivaroxaban) tests within 4 h after hospital admission.

RESULTS

A total of 210 trauma patients, admitted between 2019 and 2022, were included in the analyses. Low DOAC levels < 30 ng/mL were detected in 13.3% of the patients. In 7.1% of the patients, DOAC plasma levels ranged between 300-399 ng/mL and further 7.1% exhibited plasma concentrations > 400 ng/mL. The highest incidence of high to very high DOAC plasma concentration was observed for patients on rivaroxaban and dabigatran. A moderate correlation was observed between dabigatran plasma concentration and estimated glomerular filtration rate (rho = - 0.5338, p = 0.0003). For rivaroxaban no clear association between plasma concentration and liver or renal function could be detected. Patients on statins had significantly higher DOAC concentration in comparison with those not taking statins (153 (76-274) vs 108 (51-217) ng/mL, p = 0.046).

CONCLUSION

The current study revealed that patients on dabigatran and rivaroxaban were prone to higher DOAC plasma levels upon hospital admission in comparison with apixaban and edoxaban. DOAC plasma level measurement in trauma patients might be warranted due to unpredictively low or high plasma concentrations. However, the clinical impact of altered plasma levels on both, bleeding and thromboembolic events, remains to be determined by future studies.

Safe and effective treatment of venous Thromboembolism associated with Cancer: focus on direct Oral Anticoagulants in Asian patients

Cancer-associated thrombosis (CAT) poses a significant disease burden and the incidence in Asian populations is increasing. Anticoagulation is the cornerstone of treatment, but can be challenging due to the high bleeding risk in some cancers and the high risk of recurrent venous thromboembolism (VTE) in patients with malignancies. Direct oral anticoagulants (DOACs) are well established as first-choice treatments for VTE in non-cancer patients, offering a more convenient and less invasive treatment option than low-molecular-weight heparin (LMWH). Asian patients have exhibited comparable efficacy and safety outcomes with other races in trials of DOACs for VTE in the general population. Although no specific data are available in Asian patients with CAT, results from randomized controlled trials of apixaban, edoxaban, or rivaroxaban versus the LMWH, dalteparin, indicate that DOACs are a reasonable alternative to LMWH for anticoagulation in Asian patients with CAT. This is further supported by analyses of real-world data in Asian populations demonstrating the efficacy and safety of DOACs in Asian patients with CAT. Apixaban, edoxaban, or rivaroxaban are recommended in the most recently updated international guidelines as first-line therapy for CAT in patients without gastrointestinal or genitourinary cancers and at low risk of bleeding. An increased risk of major gastrointestinal bleeding was evident with edoxaban or rivaroxaban, but not apixaban, versus dalteparin in the clinical trials, suggesting that apixaban could be a safe alternative to LMWH in patients with gastrointestinal malignancies. Determining the optimal anticoagulant therapy for patients with CAT requires careful consideration of bleeding risk, tumor type, renal function, drug-drug interactions, financial costs, and patients' needs and preferences.

Increased Risk of Stroke Due to Non-adherence and Non-persistence with Direct Oral Anticoagulants (DOACs): Real-World Analyses Using a Nested Case-Control Study from The Netherlands, Italy and Germany

BACKGROUND

A high degree of adherence to direct oral anticoagulants is essential for reducing the risk of ischaemic stroke and systemic embolism in patients with atrial fibrillation, owing to the rapid decline in anticoagulation activity when doses are omitted (i.e. rebound effect).

OBJECTIVE

We aimed to assess the relationship between non-adherence and non-persistence with direct oral anticoagulants and the incidence of ischaemic stroke in patients with atrial fibrillation.

METHODS

A nested case-control study was conducted in the Netherlands, Italy and Germany among patients with atrial fibrillation starting direct oral anticoagulants between the drug approval date and the end of database availability. Patients with an ischaemic stroke during the follow-up were selected as cases and compared with matched controls (matched on age ± 5 years, sex, year of cohort entry date and CHA₂DS₂-VASc-score at cohort entry date). The cohort entry date was the first dispensing date. Study patients were those aged ≥ 45 years, with ≥ 1 year database history, ≥ 1 year follow-up and at least two direct oral anticoagulant dispensings after the cohort entry date. Adherence and persistence to direct oral anticoagulant treatment were defined as the proportion of days covered ≥ 80% or direct oral anticoagulant continuous use between the cohort entry date and the index date (i.e. date of ischaemic stroke), respectively.

RESULTS

In The Netherlands, Italy and Germany, 105 cases and 395 controls, 1580 cases and 6248 controls, and 900 cases and 3570 controls were included, respectively. Odds ratios (ORs) for stroke among current users who were non-adherent compared to adherent users were 0.43 (95% confidence interval [CI] 0.09-1.96) in The Netherlands, 1.11 (95% CI 0.98-1.26) in Italy and 1.21 (95% CI 1.01-1.45) in Germany. The risk of stroke was significantly higher among non-persistent users compared with persistent users in all three databases [OR 1.56 (95% CI 1.00-2.44), OR 1.48 (1.32-1.65) and OR 1.91 (95% CI 1.64-2.22), respectively]. In The Netherlands and Germany, the risk of stroke was higher the longer a patient had stopped using direct oral anticoagulants.

CONCLUSIONS

Both non-adherence (in Germany) and non-persistence increased the risk of stroke, either using a once-daily or twice-daily regime.

Expert Recommendations on the Usage of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) from India: Current Perspective and Future Direction

Non-vitamin K antagonist oral anticoagulants (NOACs) are a new class of anticoagulant drugs used in the prevention and treatment of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulation requires the integration of the correct type and dose of oral anticoagulants based on patient characteristic, and therefore therapy needs to be individualized for each patient. Growing scientific evidence from studies on NOACs has led to a better understanding of their benefits and safety. A large amount of available data creates a necessity for an adaptable practical document for the usage of NOACs in India. The current consensus, developed by experts from India, aims to give recommendations on various frequently raised clinical questions with regards to NOACs and its usage. This practical document provides a platform upon which future guidelines, policies, training, and education for the use of NOACs can be tailored.

Adherence and Persistence with Once-Daily vs Twice-Daily Direct Oral Anticoagulants Among Patients with Atrial Fibrillation: Real-World Analyses from the Netherlands, Italy and Germany

Background

Direct oral anticoagulants are available for patients with atrial fibrillation.

Objective

This study compared adherence and persistence of once-daily (QD) vs twice-daily (BID) direct oral anticoagulants in patients with atrial fibrillation.

Methods

A cohort study was conducted in three databases in the Netherlands, Italy and Germany. Patients with AF starting direct oral anticoagulants after drug approval date were included. The index date was the date of first dispensing. Study patients were restricted to those aged ≥ 18 years, ≥ 1 year database history and ≥ 1 year follow-up. Adherence to treatment was defined as the proportion of days covered ≥ 80% between the index date and the date of last dispensing of the index regimen (i.e. exposure period). The proportion of days covered was also determined during the 12-month follow-up. Persistence was defined as continuous use from index to treatment discontinuation.

Results

In the Netherlands, Italy and Germany, respectively, 6068, 32,260 and 167,445 patients were included. The mean age of the patients was 70, 77 and 74 years, and 31%, 40% and 61% were QD users, all respectively. Among QD/BID users, 93/90%, 88/86% and 77/58%, respectively were adherent during the exposure period. Persistence rates at 1 year in QD/BID users were 60/59%, 13/14% and 46/31%, respectively.

Conclusions

Adherence to treatment was high. In Germany, adherence was markedly higher in QD users compared with BID users. In Italy and the Netherlands, these differences were marginal. Persistence was low in all countries, but discontinuation was temporary. Only in Germany, persistence was markedly lower in BID users vs QD users.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-021-00289-w.

Direct Oral Anticoagulants for the Treatment of Cancer-Associated Venous Thromboembolism: A Latin American Perspective

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with cancer. On the basis of results from randomized controlled trials, direct oral anticoagulants (DOACs) are now recommended for the treatment of cancer-associated VTE. The decision to use a DOAC requires consideration of bleeding risk, particularly in patients with gastrointestinal (GI) malignancies, the cost-benefit and convenience of oral therapy, and patient preference. While efficacy with apixaban, edoxaban, and rivaroxaban versus dalteparin has been consistent in the treatment of cancer-associated VTE, heterogeneity is evident with respect to major GI bleeding, with an increased risk with edoxaban and rivaroxaban but not apixaban. Although cost and accessibility vary in different countries of Latin America, DOACs should be considered for the long-term treatment of cancer-associated VTE in all patients who are likely to benefit. Apixaban may be the preferred DOAC in patients with GI malignancies and LMWH may be preferred for patients with upper or unresected lower GI tumors. Vitamin K antagonists should only be used for anticoagulation when DOACs and low molecular weight heparin are inaccessible or unsuitable.

Long-term adherence to direct acting oral anticoagulants and the influence of health beliefs after switching from vitamin-K antagonists: Findings from the Switching Study

AIMS

Switching non-adherent patients prescribed anticoagulant treatment to a regime with less monitoring could lead to significant non-adherence. Health beliefs are known to influence medication adherence; however, the extent of this influence is unknown in patients switched from vitamin-K antagonists (VKAs) to direct oral anticoagulants (DOACs). This study aimed to determine adherence to long-term therapy in patients switched from VKAs to DOAC due to low time in therapeutic range (TTR) and if adherence is associated with health beliefs.

METHODS

The Switching Study is a longitudinal observational cohort study following patients for at least 1-year. 254 patients anticoagulated with VKAs for stroke prevention in atrial fibrillation (AF) or secondary prevention of venous thromboembolism (VTE) and TTR < 50% were recruited from anticoagulation clinics at King's College Hospital, London, UK. All participants were switched to DOAC and had health beliefs measured at baseline with VKA, 1-month and 12-months after switching.

RESULTS

Of the 220 patients who completed 12-month follow-up 39% had sub-optimal adherence measured by self-report. 23% were non-adherent according to prescriptions issued. Increasing concerns about anticoagulation over time relative to beliefs about necessity was associated with lower self-reported adherence (OR = 0.902 95%C.I: 0.836, 0.974; p = 0.008). At baseline, believing that medications in general were overused in healthcare was negatively associated with adherence to DOAC (β = -1.5, 95%C.I: -2.7, -0.3; p = 0.013).

CONCLUSIONS

Although many patients who switched were adherent to therapy long-term, between 23 and 39% of patients exhibited sub-optimal adherence: these patients can be identified through their modifiable health beliefs at the time of switching.

Electronic monitoring of adherence to once-daily and twice-daily direct oral anticoagulants in patients with atrial fibrillation: Baseline data from the SMAAP-AF trial

BACKGROUND

Nonadherence diminishes the efficacy of direct oral anticoagulants (DOACs) in patients with nonvalvular atrial fibrillation (NVAF). This report presents the baseline survey results regarding medication adherence among NVAF patients who were treated with once-daily edoxaban or twice-daily apixaban from a randomized control trial of the effect of an educational intervention on DOAC adherence.

METHODS

We prospectively studied 301 NVAF patients who were treated with edoxaban (n = 175) or apixaban (n = 126) during the 12-week observation period. Adherence was measured with an electronic monitoring system and is expressed as the percentage of days with the correct doses in the measurement period (days). Adherence to DOAC therapy was defined based on the standard threshold (≥80%) or a strict threshold (≥90%).

RESULTS

Of the 301 patients, 33 had incomplete data or protocol deviations, leaving 268 patients (edoxaban 158 and apixaban 110) for the per-protocol baseline analysis. There was no difference in adherence (threshold ≥80%) between the groups (edoxaban 95% vs apixaban 91%, P = .2), but there was a lower proportion of patients with strict adherence (threshold ≥90%) among apixaban users than among edoxaban users (edoxaban 87% vs apixaban 76%, P = .02). Multivariate analysis showed a negative relationship between apixaban use and an adherence rate ≥90% (odds ratio 0.49, 95% confidence interval [CI]: 0.25-0.94).

CONCLUSIONS

Our study showed that the proportion of DOAC users with adherence (≥80%) did not differ between the groups, but the proportion of patients with strict adherence (≥90%) was lower among those using apixaban than among those using edoxaban.

[Interdisciplinary aspects of oral anticoagulation with NOACs in atrial fibrillation]

Stroke prophylaxis with non-vitamin K-dependent oral anticoagulants (NOAKs) in patients with non-valvular atrial fibrillation (nvVHF) is now firmly established in routine clinical practice. The definition of nvVHF includes the absence of a mechanical heart valve and AF not associated with moderate- or high-grade mitral valve stenosis. The management of oral anticoagulation (OAC) requires a high degree of interdisciplinarity. Not least for this reason, uncertainties are repeatedly observed in practice, which can have far-reaching consequences for the individual patient. For this reason, a committee consisting of representatives from general medicine, geriatrics, cardiology, nephrology and neurology has gathered to identify aspects of practical relevance from the various disciplines and to jointly develop practical guidelines to improve therapy safety for patients in everyday life.

Non-Vitamin K Antagonist Oral Anticoagulants and Factors Influencing the Ischemic and Bleeding Risk in Elderly Patients With Atrial Fibrillation: A Review of Current Evidence

ABSTRACT

Non-vitamin K antagonist oral anticoagulants (NOACs) are a widely prescribed treatment to prevent stroke in patients with nonvalvular atrial fibrillation, and a therapy and preventative measure to prevent recurrences following venous thromboembolism. Optimal use of NOACs requires a thorough knowledge of the pharmacology of these drugs, as well as an understanding of patient factors affecting their use. The 4 NOACs-dabigatran, apixaban, edoxaban, and rivaroxaban are available in a range of doses suitable for differing indications and with a variety of dose reduction criteria. Identification of the correct dose is one of the key challenges in the individualization of treatment. Elderly patients with atrial fibrillation are at a greater risk of both ischemic and bleeding events than younger patients. Consequently, it is essential to achieve balance in anticoagulation strategies. Medication adherence to NOACs is important for safe and effective treatment, particularly in elderly populations. A growing body of evidence shows that once-daily dosing improves adherence and persistence to therapy, without having an impact on bleeding risk.

Dabigatran, the oral anticoagulant of choice at discharge in patients with non-valvular atrial fibrillation and COVID-19 infection: the ANIBAL protocol

Atrial fibrillation is a frequent complication among patients with severe coronavirus disease-2019 (COVID-19) infection. Both direct and indirect mechanisms through COVID-19 have been described to explain this relationship. COVID-19 infection increases the risk of developing both arterial and venous thrombotic complications through systemic coagulation activation, leading to increased mortality. Chronic oral anticoagulation is essential to reduce the thromboembolic risk among AF patients. Switching to low-molecular-weight heparin has been recommended during hospitalization for COVID-19 infection. Of note, at discharge, the prescription of direct oral anticoagulants may offer some advantages over vitamin K antagonists. However, oral anticoagulants should only be prescribed after the consideration of drug-drug interactions with antiviral therapies as well as of the risk of hepatotoxicity, which is common among individuals with severe COVID-19 pneumonia. Not all anticoagulants have the same risk of hepatotoxicity; dabigatran has shown a good efficacy and safety profile and could have a lower risk of hepatotoxicity. Furthermore, its metabolism by cytochrome P450 is absent and it has a specific reversal agent. Therefore, dabigatran may be considered as a first-line choice for oral anticoagulation at discharge after COVID-19 infection. In this review, the available information on the antithrombotic management of AF patients at discharge after COVID-19 infection is updated. In addition, a practical algorithm, considering renal and liver function, which facilitates the anticoagulation choice at discharge is presented.

A Systematic Review of Network Meta-Analyses and Real-World Evidence Comparing Apixaban and Rivaroxaban in Nonvalvular Atrial Fibrillation

There is no direct evidence comparing the 2 most commonly prescribed direct oral anticoagulants, apixaban and rivaroxaban, used for stroke prevention in nonvalvular atrial fibrillation (NVAF). A number of network meta-analyses (NMAs) of randomized control trials and real-world evidence (RWE) studies comparing the efficacy, effectiveness, and safety of apixaban and rivaroxaban have been published; however, a comprehensive evidence review across the available body of evidence is lacking. In this study, we aimed to systematically review and evaluate the clinical outcomes of apixaban and rivaroxaban using a combination of data gleaned from both NMAs and RWE studies. The review identified 21 NMAs and 5 RWE studies. The data demonstrated that apixaban was associated with fewer major bleeding events compared to rivaroxaban. There was no difference in the efficacy/effectiveness profiles between these treatments. Bleeding is a serious complication of anticoagulation therapy for the management of NVAF, and is associated with increased rates of hospitalization, morbidity, mortality, and health-care expenditure. The majority of studies in this comprehensive evidence review suggests that apixaban has a lower risk of major bleeding events compared to rivaroxaban in patients with NVAF.

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.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants: Overview of Systematic Reviews

Direct oral anticoagulants are now recommended by major guidelines as first-choice agents for both stroke prevention in non-valvular atrial fibrillation and treatment/prevention of venous thromboembolism in non-cancer patients. Although there are no published head-to-head trials comparing different direct oral anticoagulants, a growing body of evidence from indirect comparisons and observational studies is suggesting that each direct oral anticoagulant may have a specific risk profile. This review aims to (1) synthesize and critically assess the latest evidence in comparative effectiveness and safety research in the aforementioned consolidated therapeutic uses, by performing an overview of systematic reviews and (2) highlight current challenges, namely underexplored areas, where research should be directed, also considering ongoing unpublished studies. The evidence gathered so far on the risk-benefit profile of direct oral anticoagulants is appraised in the light of existing guidelines to discuss whether further implementation should be proposed.

Adherence to dabigatran etexilate in atrial fibrillation patients intended to undergo electrical cardioversion

AIMS

Effective anticoagulation in patients undergoing electrical cardioversion (ECV) for symptomatic atrial fibrillation is important to prevent adverse events. High medication adherence is a requirement. In patients with newly diagnosed atrial fibrillation (n = 169) who were intended to undergo ECV, the aim of this study was to measure self-reported short- and long-term adherence, evaluate whether dabigatran plasma concentrations reflect adherence, measure treatment satisfaction and assess whether adherence and treatment satisfaction are correlated.

METHODS AND RESULTS

Plasma concentrations (liquid-chromatography tandem mass spectrometry), the 8-point Morisky Medication Adherence Scale (MMAS-8) and the Anti-Clot Treatment Scale (ACTS) were measured after 3 weeks and 7 weeks of treatment. Combined mean peak (1-3 h after intake) and trough (10-16 h after intake) plasma concentrations were 175 (SD 109) ng/mL and 75 (SD 45) ng/mL, respectively. There was no relationship between short-term adherence (last 3 days) or long-term adherence (last 3-4 weeks) and plasma concentrations, unless the last intake was more than 48 h ago. After 7 weeks high, moderate, and low adherence, according to the MMAS-8, was seen in 74%, 21%, and 5% of patients, respectively. Treatment satisfaction was high (median ACTS score 68.5, range 46-75 points). Treatment satisfaction and adherence were not correlated.

CONCLUSION

The percentage of patients in the high adherence group (74%) was lower than expected, which is a matter of concern. Dabigatran plasma concentrations could not detect short- or long-term non-adherence, unless the drug was last taken more than 48 h ago. Treatment satisfaction did not correlate with adherence.

The selectivity and bioavailability improvement of novel oral anticoagulants: An overview

Anticoagulants have exhibited a critical role in the prevention and/or treatment of thrombotic diseases. Up to now, kinds of novel oral anticoagulants, inhibiting plasma serine proteases in the coagulation cascade, have been developed to overcome the clinical limitations of classical anticoagulants (like warfarin and heparins). Some of them, such as Apixaban, Rivaroxaban, Edoxaban, and Dabigatran, have been approved by FDA in recent years. This review summarizes the discovery and optimization of representative novel oral anticoagulants with the aim to improve selectivity and bioavailability of compounds. The impact of different targets in the cascade on bleeding risk also is discussed. We hope some more effective, selective, and safer anticoagulants can be developed in the future on the basis of these design experiences.