Edoxaban versus Warfarin in high-risk patients with atrial fibrillation: A comprehensive analysis of high-risk subgroups

Dose Reduction of Edoxaban in Patients 80 Years and Older With Atrial Fibrillation: Post Hoc Analysis of the ENGAGE AF-TIMI 48 Randomized Clinical Trial

Importance

In older patients with atrial fibrillation who take anticoagulants for stroke prevention, bleeding is increased compared with younger patients, thus, clinicians frequently prescribe lower than recommended doses in older patients despite limited randomized data.

Objective

To evaluate ischemic and bleeding outcomes in patients 80 years and older with atrial fibrillation receiving edoxaban, 60 mg vs 30 mg, and edoxaban, 30 mg vs warfarin.

Design, Setting, and Participants

The ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) was a parallel-design, double-blind, global clinical trial that randomized patients with atrial fibrillation to either one of 2 edoxaban dosing regimens or warfarin. This secondary analysis focused on patients 80 years or older without dose-reduction criteria receiving edoxaban, 60 mg vs 30 mg, as well as patients with or without dose-reduction criteria receiving edoxaban, 30 mg, vs warfarin. Study data were analyzed between October 2022 and December 2023.

Interventions

Oral edoxaban, 30 mg once daily; edoxaban, 60 mg once daily; or warfarin.

Main Outcomes and Measures

Primary net clinical outcome of death, stroke or systemic embolism, and major bleeding and each individual component.

Results

The current analysis included 2966 patients 80 years and older (mean [SD] age, 83 [2.7] years; 1671 male [56%]). Among 1138 patients 80 years and older without dose-reduction criteria, those receiving edoxaban, 60 mg vs 30 mg, had more major bleeding events (hazard ratio [HR], 1.57; 95% CI, 1.04-2.38; P = .03), particularly gastrointestinal hemorrhage (HR, 2.24; 95% CI, 1.29-3.90; P = .004), with no significant difference in efficacy end points. Findings were supported by analyses of endogenous factor Xa inhibition, a marker of anticoagulant effect, which was comparable between younger patients receiving edoxaban, 60 mg, and older patients receiving edoxaban, 30 mg. In 2406 patients 80 years and older with or without dose-reduction criteria, patients receiving edoxaban, 30 mg, vs warfarin had lower rates of the primary net clinical outcome (HR, 0.78; 95% CI, 0.68-0.91; P = .001), major bleeding (HR, 0.59; 95% CI, 0.45-0.77; P < .001), and death (HR, 0.83; 95% CI, 0.70-1.00; P = .046), whereas rates of stroke or systemic embolism were comparable.

Conclusions and Relevance

In this post hoc analysis of the ENGAGE AF-TIMI 48 randomized clinical trial, in patients 80 years and older with atrial fibrillation, major bleeding events were lower in patients randomized to receive edoxaban, 30 mg per day, compared with either edoxaban, 60 mg per day (in patients without dose-reduction criteria), or warfarin (irrespective of dose-reduction status), without an offsetting increase in ischemic events. These data support the concept that lower-dose anticoagulants, such as edoxaban, 30 mg, may be considered in older patients with atrial fibrillation even in the absence of dose-reduction criteria.

Trial Registration

ClinicalTrials.gov Identifier: NCT00781391.

Direct Oral Anticoagulants in Older and Frail Patients with Atrial Fibrillation: A Decade of Experience

INTRODUCTION

Both the prevalence of atrial fibrillation (AF) and its subsequent use of direct oral anticoagulants (DOACs) are rapidly increasing in patients of older age. In the absence of contra-indications, guidelines advocate anticoagulation based on the CHA2DS2-VASc score for all AF patients aged 75 and above. However, some practitioners are hesitant to prescribe anticoagulants to older and frail patients due to perceived elevated bleeding risks. This review delves into the comparative treatment outcomes of DOACs versus vitamin K antagonists (VKAs) in older patients with AF, particularly focusing on those of advanced age, frailty, increased risk of falling, chronic kidney disease (CKD), or with a history of major bleeding. Additionally, considerations on the use of off-label DOAC doses, the role of left atrial appendage (LAA) closure and future developments in factor XIa-inhibitors will be discussed.

RESULTS

While strong evidence supports the use of DOACs in the vital older patients with nonvalvular AF, it remains scant in frail patient groups. There is some evidence from non-randomized studies suggesting that the effect of DOACs compared with VKAs is consistent between frail and nonfrail patients. However, recent findings from a single randomized trial showed increased bleeding risks but comparable thromboembolic outcomes in frail individuals switching from VKAs to DOACs. In patients with an increased risk of falling, data suggest no relevant interaction of increased risk of falling on the effectiveness and safety of DOACs compared with warfarin. Resuming oral anticoagulants in patients with Af after major bleeding seems to be beneficial. Off-label low-dose DOAC is often prescribed to patients who were underrepresented in larger randomized trails because of an elevated risk of bleeding or overexposure to DOACs, but its effect on clinical outcomes remains uncertain.

CONCLUSIONS

DOACs are the recommended oral anticoagulant for vital older patients with AF. The scarcity of data backing DOAC use in frail individuals, those with renal impairments, or significant bleeding history underscores the necessity for further investigation. However, existing evidence suggests at least similar effectiveness and safety and potential benefits for DOACs in these patient subsets. Therefore, there is no reason to suggest these patients should be treated differently than the established guidelines regarding anticoagulation.

Differences in quality of anticoagulation care delivery according to ethnoracial group in the United States: A scoping review

Anticoagulation therapy is standard for conditions like atrial fibrillation, venous thromboembolism, and valvular heart disease, yet it is unclear if there are ethnoracial disparities in its quality and delivery in the United States. For this scoping review, electronic databases were searched for publications between January 1, 2011 - March 30, 2022. Eligible studies included all study designs, any setting within the United States, patients prescribed anticoagulation for any indication, outcomes reported for ≥ 2 distinct ethnoracial groups. The following four research questions were explored: Do ethnoracial differences exist in 1) access to guideline-based anticoagulation therapy, 2) quality of anticoagulation therapy management, 3) clinical outcomes related to anticoagulation care, 4) humanistic/educational outcomes related to anticoagulation therapy. A total of 5374 studies were screened, 570 studies received full-text review, and 96 studies were analyzed. The largest mapped focus was patients' access to guideline-based anticoagulation therapy (88/96 articles, 91.7%). Seventy-eight articles made statistical outcomes comparisons among ethnoracial groups. Across all four research questions, 79 articles demonstrated favorable outcomes for White patients compared to non-White patients, 38 articles showed no difference between White and non-White groups, and 8 favored non-White groups (the total exceeds the 78 articles with statistical outcomes as many articles reported multiple outcomes). Disparities disadvantaging non-White patients were most pronounced in access to guideline-based anticoagulation therapy (43/66 articles analyzed) and quality of anticoagulation management (19/21 articles analyzed). Although treatment guidelines do not differentiate anticoagulant therapy by ethnoracial group, this scoping review found consistently favorable outcomes for White patients over non-White patients in the domains of access to anticoagulation therapy for guideline-based indications and quality of anticoagulation therapy management. No differences among groups were noted in clinical outcomes, and very few studies assessed humanistic or educational outcomes.

Impact of the PATH Statement on Analysis and Reporting of Heterogeneity of Treatment Effect in Clinical Trials: A Scoping Review

Background

The Predictive Approaches to Treatment Effect Heterogeneity (PATH) Statement provides guidance for using predictive modeling to identify differences (i.e., heterogeneity) in treatment effects (benefits and harms) among participants in randomized clinical trials (RCTs). It distinguished risk modeling, which uses a multivariable model to predict risk of trial outcome(s) and then examines treatment effects within strata of predicted risk, from effect modeling, which predicts trial outcomes using models that include treatment, individual participant characteristics and interactions of treatment with selected characteristics.

Purpose

To describe studies of heterogeneous treatment effects (HTE) that use predictive modeling in RCT data and cite the PATH Statement.

Data Sources

The Cited By functions in PubMed, Google Scholar, Web of Science and SCOPUS databases (Jan 7, 2020 - June 5, 2023).

Study Selection

42 reports presenting 45 predictive models.

Data Extraction

Double review with adjudication to identify risk and effect modeling and examine consistency with Statement consensus statements. Credibility of HTE findings was assessed using criteria adapted from the Instrument to assess Credibility of Effect Modification Analyses (ICEMAN). Clinical importance of credible HTE findings was also assessed.

Data Synthesis

The numbers of reports, especially risk modeling reports, increased year-on-year. Consistency with consensus statements was high, except for two: only 15 of 32 studies with positive overall findings included a risk model; and most effect models explored many candidate covariates with little prior evidence for effect modification. Risk modeling was more likely than effect modeling to identify both credible HTE (14/19 vs 5/26) and clinically important HTE (10/19 vs 4/26).

Limitations

Risk of reviewer bias: reviewers assessing credibility and clinical importance were not blinded to adherence to PATH recommendations.

Conclusions

The PATH Statement appears to be influencing research practice. Risk modeling often uncovered clinically important HTE; effect modeling was more often exploratory.

Effect of edoxaban compared with other oral anticoagulants for stroke prevention in patients with atrial fibrillation: A meta-analysis

Background and aim

Current observational studies have compared the effectiveness and safety of edoxaban with other oral anticoagulants in patients with AF, but the results are still disputed. This meta-analysis was conducted to compare the effect of edoxaban in patients with AF.

Methods

We performed systematic research from the PubMed, EMBASE, and Cochrane Library databases until November 2022 to obtain relevant observational studies. Adjusted risk ratios (RRs) and 95 % confidence intervals (CIs) of the outcomes were collected and pooled by a random-effects model. This study was prospectively registered in PROSPERO (CRD42022314222).

Results

A total of 17 observational studies were included in this meta-analysis. Compared with vitamin K antagonists, edoxaban was associated with lower risks of stroke or systemic embolism (RR = 0.67, 95 % CI:0.61-0.74), major bleeding (RR = 0.54, 95 % CI:0.44-0.67), and intracranial hemorrhage (RR = 0.51, 95 % CI:0.29-0.90). Compared with dabigatran or rivaroxaban, edoxaban was associated with reduced risks of stroke or systemic embolism (dabigatran [RR = 0.76, 95 % CI:0.66-0.87]; rivaroxaban [RR = 0.81, 95 % CI:0.70-0.94]) and major bleeding (dabigatran [RR = 0.82, 95 % CI:0.69-0.98]; rivaroxaban [RR = 0.81, 95 % CI:0.70-0.94]). Compared with apixaban, edoxaban was associated with a reduced risk of stroke or systemic embolism (RR = 0.87, 95 % CI:0.79-0.97), but had similar risks of bleeding events.

Conclusions

Our current evidence suggested that edoxaban might have superior effectiveness and/or safety outcomes than vitamin K antagonists, dabigatran, rivaroxaban, and apixaban for stroke prevention in patients with AF.

Early experiences with edoxaban for stroke prevention in atrial fibrillation in the Southeast Asia region

Edoxaban, a once-daily, direct-acting oral anticoagulant, is approved to prevent stroke or systemic embolism in non-valvular atrial fibrillation (NVAF) and treat venous thromboembolism. The clinical benefit of edoxaban for stroke prevention in Asian patients with NVAF has been demonstrated in clinical and real-world studies. We share early clinical experiences with once-daily edoxaban and discuss its evidence-based use in patients with NVAF in Southeast Asia through several cases of patients at high risk, including frail patients, elderly patients with multiple comorbidities and patients with increased bleeding risk. These cases demonstrate the effectiveness and safety of once-daily edoxaban in patients with NVAF in Southeast Asia.

Very Elderly Patients With Atrial Fibrillation Treated With Edoxaban: Impact of Frailty on Outcomes

Background

Age and frailty are associated with underuse of anticoagulation in elderly patients with atrial fibrillation (AF).

Objectives

This study aimed at assessing major clinical outcomes in very elderly patients with AF treated with recommended dose edoxaban and look for a possible relation with frailty measured by a validated score.

Methods

This prospective multicenter cohort study enrolled consecutive very elderly (age ≥80 years) anticoagulation-naïve patients starting recommended doses of edoxaban. Upon entry into the study, patients were categorized into nonfrail, prefrail and frail with the SHARE-FI (Survey of Health, Ageing, and Retirement in Europe-Frailty Index) score. The primary outcome was a composite incidence of stroke/systemic embolism, major bleeding, clinically relevant nonmajor bleeding, and death between frail and fitter patients over 2 years follow-up. Secondary outcomes were frailty-related incidence of the individual components part of the composite outcome.

Results

Of the 180 screened patients, 176 were enrolled in the study. Of these, 58 (32.9%) were frail, 35 (19.8%) prefrail, and 83 (47.2%) nonfrail. The composite outcome occurred in 49 patients (18.9% per patient-year). No difference in the primary endpoint between frail and fitter patients (incidence rate ratio: 1.2; 95% CI: 0.6-2.2) was observed. On multivariable analysis, anemia was significantly related to the primary outcome (HR: 3.6; 95% CI: 1.8-7.3; P < 0.001), while frailty was not (frail vs nonfrail HR: 0.9; 95% CI: 0.5-1.8). No difference across frailty categories of the individual components of composite events was observed, except for death.

Conclusions

Anticoagulation with recommended dose edoxaban is feasible in very elderly patients with AF even if frail. (ESCAPE [Edoxaban and Frailty in Senior Individuals]; NCT03524924).

External validation of AF-BLEED for predicting major bleeding and for tailoring NOAC dose in AF patients: A post hoc analysis in the ENGAGE AF-TIMI 48

OBJECTIVE

AF-BLEED, a simple bleeding risk classifier, was found to predict major bleeding (MB) in patients with atrial fibrillation (AF) and identify AF patients at high risk of MB who might potentially benefit from a lower direct oral anticoagulant dose. This post hoc study aimed to externally validate these findings in the ENGAGE AF-TIMI 48 (Effective aNticoaGulation with factor Xa next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction study 48) trial.

METHODS

The ENGAGE AF-TIMI 48 trial randomized AF patients to higher-dose edoxaban regimen (HDER 60/30 mg) versus lower-dose edoxaban regimen (LDER 30/15 mg), with prespecified dose reduction criteria. AF-BLEED was calculated in the modified intention-to-treat cohort (n = 21,026 patients) used for primary outcome analysis. Annualized event rates and hazard ratios (HRs) were obtained for the primary composite outcome (PCO) and its single components (MB, ischemic stroke/systemic embolism and death) to compare LDER 30 mg with HDER 60 mg in both AF-BLEED classes.

RESULTS

AF-BLEED classified 2882 patients (13.7 %) as high-risk, characterized by a two- to three-fold higher MB risk than AF-BLEED classified low-risk patients. AF-BLEED classified high-risk patients randomized to LDER 30 mg demonstrated a 3.3 % reduction in MB at the cost of a 0.5 % increase in ischemic stroke/systemic embolism. LDER 30 mg resulted in a 3.1 % reduction of PCO compared to HDER 60 mg (HR of 0.81; 95%CI 0.65-1.01). Additional to existing dose reduction criteria, another 6 % of patients could potentially benefit of this dose adjustment strategy.

CONCLUSION

AF-BLEED could identify AF patients to be at high risk of major bleeding. Our findings support the hypothesis that LDER 30 mg might provide a reasonable option in AF patients with legitimate bleeding concerns.