Direct Oral Anticoagulant Use: A Practical Guide to Common Clinical Challenges

Direct oral anticoagulant therapy in adolescent venous thromboembolism: A systematic review

Adolescent venous thromboembolism (VTE) has unique challenges in management, complications, and compliance to anticoagulants. Direct oral anticoagulants (DOACs) have been approved for pediatric VTE management, with an increasing use especially in adolescents. Primary objective is to evaluate the safety and efficacy of DOAC therapy in adolescent VTE. Secondary objectives include adverse events, bleeding events, and overall mortality. A SR protocol was registered in PROSPERO 2022 (CRD42022363928). Databases were searched from inception to September 22, 2022. Studies with children aged 10-18 years, VTE diagnosis, DOAC therapy, randomized control trials (RCTs), cohort, and relevant study types were included. Studies including prophylaxis, non-DOAC therapy, arterial thrombosis, age outliers, non-relevant study types were excluded. Findings are reported in accordance to PRISMA 2020. Nine reports from five studies, published between 2016 and 2022, were included. Rivaroxaban was the most common DOAC. VTE recurrence was 0.02% in the rivaroxaban phase III trial and one patient in the dabigatran phase IIb/III trial. Complete/partial thrombus resolution (CR/PR) was 76.6% in the rivaroxaban phase III trial, and 83.9% in the dabigatran phase IIb/III trial. CR/PR was found to be 68.4% in Dhaliwal et al. study and 83.3% in Hassan et al. study. Major bleeding occurred in one patient. Headache and gastrointestinal symptoms were commonly seen. All-cause mortality occurred in a patient due to cancer progression. DOAC therapy in adolescent VTE had CR/PR in two-thirds of the patients, with low incidence of VTE recurrence and major bleeding. As there are only two randomized controlled trial (RCTs), future adolescents' studies are required to validate our results.

Safety and Effectiveness of Four-Factor Prothrombin Complex Concentrate in Special Populations with INR Below 2: A Post-Marketing Surveillance Study

INTRODUCTION

We previously conducted a prospective, observational post-marketing surveillance study to assess the safety and effectiveness of four-factor prothrombin complex concentrate (4F-PCC) for rapid vitamin K antagonist (VKA) reversal in Japanese patients.

METHODS

This subgroup analysis compared the safety, especially thromboembolic events (TEEs), and effectiveness of 4F-PCC by stratifying patients into two subgroups according to baseline international normalized ratio (INR) levels with < 2.0 and ≥ 2.0.

RESULTS

Of 1271 eligible patients, 215 (17.9%) had INR < 2.0 and 987 (82.1%) had INR ≥ 2.0. Overall baseline characteristics were similar between groups; age (74.0 years vs 74.0 years), body mass index (22.1 kg/m2 vs 21.9 kg/m2), ratio of inpatients (90.2% vs 88.7%), manifested atrial fibrillation (46.0% vs 48.8%). Median INRs at baseline were 1.72 (minimum 0.92, maximum 1.99) in the INR < 2.0 group and 2.95 (2.00, 27.11) in the INR ≥ 2.0 group. The most common reason for 4F-PCC administration was intracranial hemorrhage (67.0% vs 59.5%), and lesser gastrointestinal bleeding (0.9% vs 7.5%). After 4F-PCC administration (average doses 24.5 IU/kg [INR < 2.0 group] and 29.2 IU/kg [INR ≥ 2.0 group]), INRs were significantly reduced to 1.21 (- 28%) and 1.31 (- 68%), respectively, and resulted in hemostasis in a similarly rapid manner. The incidences of adverse drug reactions were 3.7% in each group. TEEs occurred in 4 (1.9%) patients in the INR < 2.0 group and 11 (1.1%) patients in the INR ≥ 2.0 group and were predominantly composed of stroke, while similar rates (67.0% vs 62.9%) of bleeding events post-anticoagulant resumption were observed between groups.

CONCLUSION

This study supports the favorable tolerability and efficacy of 4F-PCC regardless of baseline INR (< 2.0 or ≥ 2.0), with a prompt reduction of INR and substantial hemostatic effectiveness in the real-world setting for patients requiring urgent VKA reversal, although no indicated 4F-PCC dose for VKA reversal exists for INR < 2.0 to date.

Comparative effectiveness of warfarin management strategies: a systematic review and network meta-analysis

Background

The management of warfarin therapy presents clinical challenges due to its narrow therapeutic index. We aimed to evaluate the comparative effectiveness of different management strategies in patients using warfarin.

Methods

PubMed, Embase, Cochrane CENTRAL, CINAHL, and EBSCO Open Dissertation were searched from inception to 8 May 2024. Randomized controlled trials that compared the following interventions: patient self-management (PSM), patient self-testing (PST), anticoagulation management services (AMS), and usual care in patients prescribed warfarin for any indication were included. Risk ratios (RR) with 95% confidence interval (CI) were estimated using a random-effects model. Surface under the cumulative ranking curves (SUCRA) were used to rank different interventions. The certainty of evidence was assessed using the Confidence in Network Meta-Analysis (CINeMA) online platform. This study is registered with PROSPERO (CRD42023491978).

Findings

Twenty-eight trials involving 8100 participants were included, with follow-up periods of 1-24 months. Mean warfarin dosages were 4.9-7.2 mg/day. Only PSM showed a significant reduction of major TE risk compared with usual care (RR = 0.41; 95% CI: 0.24, 0.71; I2 = 0.0%) with moderate certainty of evidence. The 97.6% SUCRA also supported the beneficial effects of PSM over other interventions. The combined direct and indirect evidence showed significantly higher TTR in PSM compared with usual care (MD = 7.39; 95% CI: 2.39, 12.39), with very low certainty. However, direct evidence showed non-significant TTR improvement (MD = 6.49; 95% CI: -3.09, 16.07, I2 = 96.1%). No differences across various strategies were observed in all-cause mortality, major bleeding, stroke, transient ischemic attack, and hospitalization.

Interpretation

PSM reduces the risk of major TE events compared with usual care, tends to improve anticoagulation control, and should be considered where appropriate.

Funding

Agency for Healthcare Research and Quality (grant ID 5R18HS027960).

Efficacy and Safety of Direct Oral Anticoagulants for Acute Treatment of Venous Thromboembolism in Older Adults: A Network Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

This systematic review and network meta-analysis aimed to evaluate the efficacy and safety of direct oral anticoagulants (DOACs) in adults aged 75 and over undergoing acute venous thromboembolism (VTE) treatment.

METHODS

PubMed, Embase and the CENTRAL were searched up to 25 December 2023. The incidence of VTE recurrence and bleeding events was assessed. Employing a frequentist network meta-analysis approach, interventions not directly compared could be indirectly assessed through the 95% confidence interval (CI), enhancing the interpretability of the search results. The surface under the cumulative ranking curves (SUCRA) was utilized to generate the relative ranking probabilities for each group.

RESULTS

Our study, analysing 6 randomised controlled trials with 3665 patients, compares direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in adults aged 75 and over with acute venous thromboembolism. Edoxaban reduces VTE recurrence risk compared with VKAs (risk ratio [RR] .50, 95% CI 0.27 - .95), while apixaban significantly decreases bleeding risk compared with VKAs (RR .23, 95% CI 0.08 - .69), edoxaban (RR .28, 95% CI 0.09 - .86) and rivaroxaban (RR .28, 95% CI 0.09 - .86). Despite low overall evidence quality, apixaban consistently ranks highest for both efficacy and safety. Findings underscore the nuanced efficacy-safety balance in this population, emphasizing cautious interpretation due to evidence limitations.

CONCLUSION

Apixaban emerges as a favourable choice for acute VTE treatment in the elderly, displaying reduced bleeding risk compared to other treatments while maintaining comparable efficacy. Future studies should explore diverse anticoagulants efficacy and safety in older populations. Additionally, clinical prediction models tailored to geriatric cohorts are crucial for guiding treatment duration decisions.

Hypersensitivity reaction to rivaroxaban with a successful switch to apixaban: A case report

Key Clinical Message

The precise management of hypersensitivity reactions to direct oral anticoagulants (DOACs) and the potential for cross-reactivity among different DOACs remain unclear. In such cases, switching between DOACs may be feasible and could be considered, but close monitoring for adverse effects is essential, tailored to individual patient responses and tolerability.

Abstract

Hypersensitivity reactions to DOACs, though considered rare, have been documented. This report describes the case of a 28-year-old male with a history of testicular cancer who was recently diagnosed with deep vein thrombosis. He was referred to an outpatient pharmacotherapy clinic due to suspected rivaroxaban-induced cutaneous reactions. Following a thorough evaluation, his anticoagulant therapy was switched from rivaroxaban to apixaban. This change was successfully implemented, and no hypersensitivity symptoms recurred during subsequent follow-up. This case demonstrates the importance of recognizing potential adverse reactions to DOACs and illustrates the feasibility of switching anticoagulants under close medical supervision to ensure patient safety and effective treatment.

Design and rationale for REVERXaL: A real-world study of patients with factor Xa inhibitor-associated major bleeds

BACKGROUND

The prevalence of anticoagulation treatment is increasing as an aging global population faces a high burden of cardiovascular comorbidities. Direct oral anticoagulants, including factor Xa inhibitors (FXai), are replacing vitamin K antagonists as the most commonly prescribed treatment for reducing risk of thrombotic events. While the risk of FXai-associated spontaneous bleeds is established, less is understood about their management and the effect of treatment on clinical and patient-reported outcomes. The primary objectives of the REVERXaL study are to describe patient characteristics, health care interventions during the acute-care phase, in-hospital outcomes, and associations between timing of reversal/replacement agent administration and in-hospital outcomes. Secondary/exploratory objectives focus on clinical assessments and patient-reported outcome measures (PROMs) at 30 and 90 days.

METHODS

REVERXaL is a multinational, observational study of hospitalized patients with FXai-associated major bleeds in Germany, Japan, the United Kingdom, and the United States. The study includes 2 cohorts of approximately 2000 patients each. Cohort A is a historic cohort for whom medical chart data will be collected from hospitalization to discharge for patients admitted for major bleeds during FXai use within 2 years prior to enrollment of Cohort B. Cohort B will prospectively enroll patients administered any reversal/replacement agent during hospitalization to manage FXai-associated major bleeds and will include the collection of clinical outcomes and PROMs data over 3 months.

CONCLUSIONS

REVERXaL will generate insights on patient characteristics, treatment approaches, and associated outcomes in patients hospitalized with FXai-associated major bleeds. These data may inform clinical practice and streamline treatment pathways in this population.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; unique identifier: NCT06147830.

Direct Oral Anticoagulants: Probability of Recurrent Venous Thromboembolism and Bleeding Risk in an Obese Population

BACKGROUND

Direct-acting oral anticoagulants (DOACs) have become the preferred drugs for managing venous thromboembolism (VTE). Despite their advantages over vitamin K antagonists such as warfarin, their use in obese patients remains controversial with many providers reluctant to switch patients managed on warfarin. Outcome research that opts to increase provider confidence when prescribing DOACs for patients with obesity will be invaluable.

OBJECTIVE

This investigation evaluated whether patients with a body mass index (BMI) 35 kg/m2 or greater who were prescribed a DOAC had a higher risk for a recurrent VTE or bleed event relative to warfarin.

METHODS

The study was conducted in West Virginia which has the highest rate of obesity in the United States.

RESULTS

Of the total study population (1633), 2.3% (37) had a recurrent thrombotic event, 5.5% (89) had a major bleed event, and 10.7% (174) had some type of bleeding event. No individual patient characteristic was associated with recurrent thrombosis-including BMI. Older age, antiplatelet use, and taking a medication with a theoretical risk of increasing the effect of DOACs were associated with any and major bleeding events. The use of warfarin was associated with major bleeding events more frequently versus a DOAC. Body mass index was not a predictor for recurrent VTE or any bleed or major bleed events.

CONCLUSIONS

These findings support the conclusion that DOACs are an appropriate and effective drug class for the management of VTE in patients with obesity.

Effectiveness and safety in non-valvular atrial fibrillation patients switching from warfarin to direct oral anticoagulants in US healthcare claims

INTRODUCTION

There is a paucity of real-world studies examining the risks of stroke/systemic embolism (SE) and major bleeding (MB) among non-valvular atrial fibrillation (NVAF) patients switching from warfarin to a direct oral anticoagulant (DOAC). This retrospective study was conducted to compare the stroke/SE and MB risks between patients switched from warfarin to apixaban, dabigatran, or rivaroxaban in real-world clinical practice.

MATERIALS AND METHODS

This study used data from four United States commercial claims databases from January 1, 2012 to June 30, 2019. The study population included NVAF patients initially treated with warfarin and switched to apixaban, dabigatran, or rivaroxaban within 90 days of their warfarin prescription ending. Patients were matched 1:1 between the DOACs in each database using propensity scores and then pooled for the final analysis. Cox proportional hazards models were used to calculate the risk of stroke/SE and MB.

RESULTS AND CONCLUSIONS

The final population consisted of 2,611 apixaban-dabigatran, 12,165 apixaban-rivaroxaban, and 2,672 dabigatran-rivaroxaban pairs. Apixaban vs. dabigatran was associated with a lower risk of stroke/SE (hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.39-0.96) and MB (HR: 0.67; 95% CI: 0.50-0.91). Apixaban vs. rivaroxaban was associated with a similar risk of stroke/SE (HR: 0.88; 95% CI: 0.73-1.07) and a lower risk of MB (HR: 0.60; 95% CI: 0.52-0.68). There was no significant difference in either risk between dabigatran and rivaroxaban. These results provide important insights into how the risks of stroke/SE and MB for NVAF patients vary when switching from warfarin to different DOACs.

Therapeutic Potential of FXI Inhibitors: Hype or Hope?

Significant advancements have shaped the landscape of anticoagulant therapy in the past two decades, including the introduction of direct oral anticoagulants (DOACs), characterized by favorable safety and efficacy profiles and reduced drug-to-drug or food interaction resulting in excellent patient compliance. However, residual concerns still exist with standard-of-care anticoagulant therapy, including the inability to use DOACs in several clinical settings and the need to further reduce the risk of bleeding. Recent improvements in the understanding of the mechanisms behind thrombus formation have led to the awareness that the intrinsic pathway of the coagulation cascade may play an important role in pathological thrombosis, but not in hemostasis. This has represented the rationale for targeting this pathway with factor XI (FXI) inhibitors, with the aim of uncoupling hemostasis and thrombosis. Clinical evidence from patients with FXI deficiency further supports this concept. A number of compounds with different mechanisms of action have been developed to target FXI (i.e., asundexian, abelacimab, Ionis-FXIRx, milvexian, osocimab, and Xisomab 3G). To date, the majority of available trials have not gone beyond completion of phase 2 and results are conflictive making it difficult to appraise the clinical benefit of these compounds in the different clinical settings where they have been tested (i.e., atrial fibrillation, acute ischemic stroke, acute myocardial infarction, end-stage renal disease, total knee arthroplasty). Moreover, the largest phase 3 randomized trial designed to test the efficacy of asundexian over apixaban in patients with atrial fibrillation, the OCEANIC-AF, has been prematurely stopped as a result of the inferior efficacy of asundexian. In this review we discuss the pharmacological properties and available evidence generated thus far for factor XI inhibitors, providing a perspective on the current state of these drugs.

predicTTE: An accessible and optimal tool for time-to-event prediction in neurological diseases

Time-to-event prediction is a key task for biological discovery, experimental medicine, and clinical care. This is particularly true for neurological diseases where development of reliable biomarkers is often limited by difficulty visualising and sampling relevant cell and molecular pathobiology. To date, much work has relied on Cox regression because of ease-of-use, despite evidence that this model includes incorrect assumptions. We have implemented a set of deep learning and spline models for time-to-event modelling within a fully customizable 'app' and accompanying online portal, both of which can be used for any time-to-event analysis in any disease by a non-expert user. Our online portal includes capacity for end-users including patients, Neurology clinicians, and researchers, to access and perform predictions using a trained model, and to contribute new data for model improvement, all within a data-secure environment. We demonstrate a pipeline for use of our app with three use-cases including imputation of missing data, hyperparameter tuning, model training and independent validation. We show that predictions are optimal for use in downstream applications such as genetic discovery, biomarker interpretation, and personalised choice of medication. We demonstrate the efficiency of an ensemble configuration, including focused training of a deep learning model. We have optimised a pipeline for imputation of missing data in combination with time-to-event prediction models. Overall, we provide a powerful and accessible tool to develop, access and share time-to-event prediction models; all software and tutorials are available at www.predictte.org.

To treat or not to treat: a comparative effectiveness analysis of oral anticoagulant outcomes among U.S. nursing home residents with atrial fibrillation

BACKGROUND

Nursing home residents with atrial fibrillation are at high risk for ischemic stroke, but most are not treated with anticoagulants. This study compared the effectiveness and safety between oral anticoagulant (OAC) users and non-users.

METHODS

We conducted a new-user retrospective cohort study by using Minimum Data Set 3.0 assessments linked with Medicare claims. The participants were Medicare fee-for-service beneficiaries with atrial fibrillation residing in US nursing homes between 2011 and 2016, aged ≥ 65 years. The primary outcomes were occurrence of an ischemic stroke or systemic embolism (effectiveness), occurrence of intracranial or extracranial bleeding (safety) and net clinical outcome (effectiveness or safety outcomes). Secondary outcomes included total mortality and a net clinical and mortality outcome. Cox proportional hazards and Fine and Grey models estimated multivariable adjusted hazard ratios (aHRs) and sub-distribution hazard ratios (sHRs).

RESULTS

Outcome rates were low (effectiveness: OAC: 0.86; non-users: 1.73; safety: OAC: 2.26; non-users: 1.75 (per 100 person-years)). OAC use was associated with a lower rate of the effectiveness outcome (sHR: 0.69; 95% Confidence Interval (CI): 0.61-0.77), higher rates of the safety (sHR: 1.70; 95% CI: 1.58-1.84) and net clinical outcomes (sHR: 1.20; 95% CI: 1.13-1.28) lower rate of all-cause mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61), and lower rate of the net clinical and mortality outcome (sHR: 0.60; 95% CI: 0.59-0.61). Warfarin users, but not DOAC users, had a higher rate of the net clinical outcome versus OAC non-users.

CONCLUSIONS

Our results support the benefits of treatment with OACs to prevent ischemic strokes and increase longevity, while highlighting the need to weigh apparent benefits against elevated risk for bleeding. Results were consistent with net favorability of DOACs versus warfarin.

Safety, tolerability, pharmacokinetics and pharmacodynamics of milvexian with aspirin and/or clopidogrel in healthy participants

Milvexian, an oral activated Factor XI (FXIa) inhibitor, is in clinical studies where it may be combined with antiplatelet agents, including aspirin and/or clopidogrel, to prevent thromboembolic diseases. This phase I trial assessed safety, pharmacokinetics, and pharmacodynamics of milvexian coadministration with aspirin and/or clopidogrel in healthy participants through 3 drug-drug interaction studies using a 3-period, 3-treatment, crossover design. A total of 113 participants were randomized to receive milvexian (200 mg; twice daily for 5 days) or matched placebo coadministered with once-daily aspirin (325 mg for 5 days) and/or clopidogrel (Day 1: 300 mg; Days 2-5: 75 mg). Milvexian was safe and well tolerated, with and without aspirin and/or clopidogrel. Eight mild bleeding adverse events (AEs) were reported in 5 of 113 participants across various treatment arms. Peak and total exposures of milvexian were similar with or without clopidogrel and/or aspirin. Exposure-dependent prolongation of activated partial thromboplastin time and reduction of FXI clotting activity by milvexian were similar with coadministration of aspirin and/or clopidogrel. Milvexian, with or without coadministration of aspirin and/or clopidogrel, did not affect bleeding time or platelet aggregation. Administration of milvexian alone or with aspirin and/or clopidogrel was safe and well tolerated without increased incidence of AEs, including bleeding. Pharmacokinetic and pharmacodynamic effects of milvexian, including bleeding time, were similar with or without aspirin and/or clopidogrel.ClinicalTrials.gov Identifier: NCT03698513.

To stop or not to stop novel oral anticoagulants prior to performing joint interventional maneuvers? Evidence from a prospective study that the therapy can be maintained

Anticoagulation is common in patients undergoing routine musculoskeletal interventional maneuvers. Previous retrospective studies have established the safety of continuing anticoagulation with novel oral anticoagulants (NOACs) when performing this kind of interventions. Indeed, ultrasound (US)-guided interventional maneuvers have shown a superior safety profile compared to blind anatomical maneuvers. To evaluate prospectively the periprocedural bleeding events in NOAC-anticoagulated patients undergoing interventional articular or periarticular procedures. Consecutive patients diagnosed with inflammatory or degenerative rheumatologic pathology requiring interventional maneuvers were prospectively recruited. Group 1 was treated with NOACs, group 2 was treated with vitamin K antagonists, and group 3 was not anticoagulated. Prior to the international maneuver, NOAC therapy was continuously administered, in regimens dictated by the underlying anticoagulation indication. Demographics, comorbidities, laboratory parameters, locally administered medication (corticosteroids or viscosupplementation), interventional maneuver location, needle size, and local bleeding events were recorded. Post-procedural control was performed at 30 min, 48 h, and 7 days. No articular/periarticular bleeding event occurred in patients treated with NOACs, regardless of their type and dosage, locally administered medication, needle size, location, and number of interventions per individual. Several patients in all groups developed small superficial ecchymoses at the injection site. Our results suggest that NOACs are safe to be used in a continuous regimen prior to US-guided injections, even as dual antithrombotic therapy (in combination with aspirin). The use of lower gauge needles, chosen for viscosupplementation therapy, was not burdened with adverse effects on the procedural outcome. Key Points • Currently, no prospective studies have been performed to establish the safety of continuous NOAC anticoagulation when performing routine intra- or periarticular interventional maneuvers. • The study offers an extensive view on a wide spectrum of intra- and periarticular interventional maneuvers including anatomic targets and needle sizes that were not previously assessed. • The study offers a perspective into performing repetitive maneuvers in the same patient, both over a short time and at longer intervals. • The zero periprocedural bleeding risk observed in our study may reassure practitioners and suggest that US-guided interventional therapeutic interventions are safe in patients treated with a continuous regimen of different NOACs.

Direct Oral Anticoagulants Exhibit Lower Risks of Mortality and Bleeding Compared to Vitamin K Antagonists in Atrial Fibrillation Patients on Chronic Hemodialysis: A Systematic Review and Meta-Analysis

This meta-analysis aimed to assess the outcomes of patients with atrial fibrillation undergoing chronic hemodialysis, comparing the effectiveness of direct oral anticoagulants (DOACs) and vitamin K antagonists. A systematic search was conducted across various databases including PubMed, Embase, and Google Scholar. Efficacy outcomes focused on the risk of stroke and mortality, whereas safety outcomes assessed the risk of bleeding. Review Manager generated forest plots for data synthesis. Statistical significance was set at P < 0.05, and random-effects models were used. Subgroup analysis identified the sources of heterogeneity. Nine studies met the inclusion criteria for the final analysis. The risk of all-cause stroke [risk ratio (RR): 0.64; 95% confidence interval (CI): 0.51-0.81; P = 0.0001; I2 = 0%], ischemic stroke (RR: 0.53; 95% CI: 0.29-0.96; P = 0.04; I2 = 0%), all-cause mortality (RR: 0.73; 95% CI: 0.60-0.88; P = 0.001; I2 = 71%), major bleeding (RR: 0.63; 95% CI: 0.52-0.76; P < 0.00001; I2 = 44%), gastrointestinal bleeding (RR: 0.67; 95% CI: 0.53-0.85; P = 0.0009; I2 = 36%), intracranial hemorrhage (RR: 0.57; 95% CI: 0.38-0.84; P = 0.004; I2 = 0%) were lower in the DOAC group compared with the vitamin K antagonist group. The risk of cardiovascular-related death (RR: 1.34; 95% CI: 0.69-2.60; P = 0.39; I2 = 0%), clinically relevant nonmajor bleeding (RR: 0.90; 95% CI: 0.75-1.08; P = 0.26; I2 = 28%), and hemorrhagic stroke (RR: 0.36; 95% CI: 0.06-2.24; P = 0.28; I2 = 10%) showed no significant differences. In conclusion, the risks of all-cause stroke, ischemic stroke, all-cause mortality, major bleeding, gastrointestinal bleeding, and intracranial hemorrhage in patients with atrial fibrillation undergoing chronic hemodialysis were lower in the DOAC group.

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-Acting Oral Anticoagulants and Antiseizure Medications for Atrial Fibrillation and Epilepsy and Risk of Thromboembolic Events

Importance

Direct-acting oral anticoagulants (DOACs) are commonly prescribed with antiseizure medications (ASMs) due to concurrency of and the association between atrial fibrillation (AF) and epilepsy. However, enzyme-inducing (EI) ASMs may reduce absorption and accelerate metabolism of DOACs, potentially lowering DOAC levels and elevating thromboembolism risk.

Objective

To assess the rates of thromboembolic and major bleeding events in adults with AF and epilepsy dispensed DOACs and EI ASMs vs DOACs with non-EI ASMs.

Design, Setting, and Participants

This active-comparator, new-user cohort study included US health care data from the Clinformatics Data Mart database from October 2010 to September 2021 for a nationally representative population of adults with AF and epilepsy.

Exposure

Evaluations included episodes of contiguous coadministration of DOACs for AF with EI ASMs (exposed) or non-EI ASMs (referent) for epilepsy.

Main Outcomes and Measures

Thromboembolic events (primary outcome) and major bleeding events (secondary outcome) were identified based on a series of validated, diagnosis-based coding algorithms. Data-adaptive, high-dimensional propensity score matching was used to control for observed confounders and proxies for unobserved confounders. Adjusted hazard ratios (AHRs) were estimated using Cox proportional hazards regression models with robust variance estimators to account for clustering within matched pairs.

Results

This study included 14 078 episodes (median age, 74 [IQR, 67-81]; 52.4% female) and 14 158 episodes (median age, 74 [IQR, 67-81]; 52.4% female) of incident DOAC and ASM use that met eligibility criteria for assessment of thromboembolic and major bleeding outcomes, respectively. Incidence was 88.5 per 1000 person-years for thromboembolic events and 68.3 per 1000 person-years for bleeding events. Compared with use of non-EI ASMs, use of EI ASMs with DOACs was not associated with a difference in risk of thromboembolic events (AHR, 1.10; 95% CI, 0.82-1.46) but was associated with a reduction in risk of major bleeding events (AHR, 0.63; 95% CI, 0.44-0.89).

Conclusions and Relevance

In this cohort study, EI ASMs were not associated with alteration in DOAC efficacy. Further research is needed on the reduction in bleeding risk associated with EI ASMs, as this may suggest that pharmacokinetic interactions are associated with lowering DOAC levels without negating therapeutic effects.

Anesthetic Choice for Percutaneous Transcatheter Closure of the Left Atrial Appendage: A National Anesthesia Clinical Outcomes Registry Analysis

CONTEXT

Left atrial appendage closure (LAAC) was developed as a novel stroke prevention alternative for patients with atrial fibrillation, particularly for those not suitable for long-term oral anticoagulant therapy. Traditionally, general anesthesia (GA) has been more commonly used primarily due to the necessity of transesophageal echocardiography.

AIMS

Compare trends of monitored anesthesia care (MAC) versus GA for percutaneous transcatheter LAAC with endocardial implant and assess for independent variables associated with primary anesthetic choice.

SETTINGS AND DESIGN

Multi-institutional data collected from across the United States using the National Anesthesia Clinical Outcomes Registry.

MATERIAL AND METHODS

Retrospective data analysis from 2017-2021.

STATISTICAL ANALYSIS USED

Independent-sample t tests or Mann-Whitney U tests were used for continuous variables and Chi-square tests or Fisher's exact test for categorical variables. Multivariate logistic regression was used to assess patient and hospital characteristics.

RESULTS

A total of 19,395 patients underwent the procedure, and 352 patients (1.8%) received MAC. MAC usage trended upward from 2017-2021 (P < 0.0001). MAC patients were more likely to have an American Society of Anesthesiologists (ASA) physical status of≥ 4 (33.6% vs 22.89%) and to have been treated at centers in the South (67.7% vs 44.2%), in rural locations (71% vs 39.5%), and with lower median annual percutaneous transcatheter LAAC volume (102 vs 153 procedures) (all P < 0.0001). In multivariate analysis, patients treated in the West had 85% lower odds of receiving MAC compared to those in the Northeast (AOR: 0.15; 95% CI 0.03-0.80, P = 0.0261).

CONCLUSIONS

While GA is the most common anesthetic technique for percutaneous transcatheter closure of the left atrial appendage, a small, statistically significant increase in MAC occurred from 2017-2021. Anesthetic management for LAAC varies with geographic location.

Heparin-Induced Thrombocytopenia (HIT) in the Direct Oral Anticoagulants (DOAC) Era

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is an uncommon complication of heparin therapy with significant risk for severe morbidity and mortality. We investigated the role and outcome of direct oral anticoagulants (DOACs) for the management of HIT.

METHODS

After institutional review board (IRB) approval, a retrospective review was performed identifying all patients with positive HIT serotonin-release assays between 2020 and 2022 at two hospitals. The demographic and clinical variables were collected as follows: initial anticoagulant, dosing and indication, interval before onset of HIT, thrombotic complications, platelet nadir and recovery, direct thrombin inhibitor (DTI) and DOAC usage, and clinical outcomes.

RESULTS

15 patients were included in the study. 8 underwent a vascular procedure, 3 had cardiac surgery, 1 patient had both and was included in both groups, and 5 patients had either noncardiac, nonvascular surgery, or no surgery. 14 patients received unfractionated heparin (93% with therapeutic dosing), and 1 received prophylactic enoxaparin prior to diagnosis of HIT. The average time to diagnosis of HIT was 10.77 days after initial anticoagulation. In-hospital mortality was 27%, related to Covid-19 infection (3/4) and intracranial hemorrhage (1/4). 40% developed thrombosis (67% venous, 33% arterial) after the diagnosis of HIT. 8/11 survivors were discharged on a DOAC. With DOAC therapy, platelet counts rebounded to an average of 265K ( ± 104.6 K) within an average of 2.3 days and 364K ( ± 273.9 K) within 30 days after initiation of a DOAC. No recurrent thrombosis occurred after DOAC administration and only one patient had persistent thrombocytopenia within 30 days.

CONCLUSIONS

Mortality and thrombosis (arterial and venous) are common complications in patients diagnosed with HIT. In patients who survive to discharge, DOACs are the most common discharge antithrombotic agent, with low rates of recurrent thrombosis and thrombocytopenia.

Observational study of frailty in older Japanese patients with non-valvular atrial fibrillation receiving anticoagulation therapy

The number of patients with atrial fibrillation is increasing, and frailty prevalence increases with age, posing challenges for physicians in prescribing anticoagulants to such patients because of possible harm. The effects of frailty on anticoagulant therapy in older Japanese patients with nonvalvular atrial fibrillation (NVAF) are unclear. Herein, we prescribed rivaroxaban to Japanese patients with NVAF and monitored for a mean of 2.0 years. The primary endpoint was stroke or systemic embolism. The secondary endpoints were all-cause or cardiovascular death, composite endpoint, and major or non-major bleeding. Frailty was assessed using the Japanese long-term care insurance system. A multiple imputation technique was used for missing data. The propensity score (PS) was obtained to estimate the treatment effect of frailty and was used to create two PS-matched groups. Overall, 5717 older patients had NVAF (mean age: 73.9 years), 485 (8.5%) were classified as frail. After PS matching, background characteristics were well-balanced between the groups. Rivaroxaban dosages were 10 and 15 mg/day for approximately 80% and the remaining patients, respectively. Frailty was not associated with the primary endpoint or secondary endpoints. In conclusion, frailty does not affect the effectiveness or safety of rivaroxaban anticoagulant therapy in older Japanese patients with NVAF.Trial registration: UMIN000019135, NCT02633982.

Adverse events of direct factor Xa inhibitors: a disproportionality analysis of the FAERS database

OBJECTIVES

Direct factor Xa inhibitors rivaroxaban, apixaban, and edoxaban, commonly used direct oral anticoagulant (DOAC), are widely used to prevent and treat stroke and venous thromboembolic events in patients with atrial fibrillation (AF). This study aimed to assess and compare reports of adverse events associated with rivaroxaban, apixaban, and edoxaban, including hemorrhagic and non-hemorrhagic events.

METHODS

Reporting odds ratio (ROR), proportional reporting ratio (PRR), Medications and Health Care Products Regulatory Agency (MHRA), and the information component (IC) were used to perform a risk assessment of adverse event reports in the FDA Adverse Event Reporting System (FAERS) database for the years 2018-2022.

RESULTS

Combined with disproportionality analysis in different backgrounds, the salient risks of the three-factor Xa inhibitors varied. Rivaroxaban had the most significant risk of hemorrhage, apixaban had a higher incidence and risk of death, cardiac and cerebral adverse events, and edoxaban showed a more prominent risk in the kidneys and urinary system.

CONCLUSION

Hemorrhage is a common risk with factor Xa inhibitors, with rivaroxaban being the most significant. Apixaban and edoxaban also showed significant association with non-hemorrhagic adverse events, and increased attention to non-hemorrhagic adverse events is needed in clinical use.

A Pilot Study Describing DOAC Level Results and Association With Clinical Outcomes

Purpose: Describe direct oral anticoagulant (DOAC) level ordering and interpretation practices in association with clinical outcomes at a vascular medicine clinic. Methods: This study was a retrospective, observational study including patients who had a DOAC level ordered and assessed while on DOAC therapy. The primary outcome was the proportion of DOAC levels within previously reported ranges. Secondary outcomes included thrombotic events, major and clinically relevant non-major bleeding events, and the proportion of DOAC level results which prompted a change in the therapeutic plan. Results: A total of 43 patients who had a DOAC level ordered while on DOAC therapy were included in the study. More patients were on apixaban than other DOACs, and the most common indication for anticoagulation was deep vein thrombosis (DVT) or pulmonary embolism (PE). The most common reasons for ordering DOAC levels included history of gastric bypass (n = 20) and drug-drug interactions (n = 8). Most patients on apixaban had in-range levels (n = 24) compared to out of-range levels (5 patients). More patients on rivaroxaban had a level out-of-range (n = 10) than in-range (n = 4). One patient had a DVT, resulting in hospitalization and change in DOAC therapy. Two patients had bleeding events, with 1 hospitalization and change in DOAC therapy. DOAC level results also prompted changes in therapeutic plans for 9 of the patients. Conclusion: DOAC level results did not always correlate with expected outcomes, and further research is warranted to clarify which clinical situations may benefit from ordering DOAC levels.

Common P-glycoprotein (ABCB1) polymorphisms do not seem to be associated with the risk of rivaroxaban-related bleeding events: Preliminary data

Introduction

Considering conflicting previous reports, we aimed to evaluate whether the common ABCB1 polymorphisms (rs1128503, rs2032582, rs1045642, rs4148738) affected the risk of bleeding in rivaroxaban-treated patients.

Materials and methods

We report preliminary data from a larger nested case-control study. Consecutive adults started on rivaroxaban for any indication requiring > 6 months of treatment were followed-up to one year. Patients who experienced major or non-major clinically relevant bleeding during the initial 6 months were considered cases, whereas subjects free of bleeding over > 6 months were controls. The polymorphisms of interest (rs1128503, rs2032582, rs1045642, rs4148738) were in a strong linkage disequilibrium, hence patients were classified regarding the "load" of variant alleles: 0-2, 3-5 or 6-8. The three subsets were balanced regarding a range of demographic, comorbidity, comedication and genetic characteristics. A logistic model was fitted to probability of bleeding.

Results

There were 60 cases and 220 controls. Raw proportions of cases were similar across the subsets with increasing number of ABCB1 variant alleles (0-2, N = 85; 3-6, N = 133; 6-8, N = 62): 22.4%, 21.8%, and 19.4%, respectively. Fully adjusted probabilities of bleeding were also similar across the subsets: 22.9%, 27.5% and 17.7%, respectively. No trend was observed (linear, t = -0.63, df = 273, P = 0.529; quadratic, t = -1.10, df = 273, P = 0.272). Of the 15 identified haplotypes, the completely variant (c.1236T_c.2677T(A)_c.3435T_c.2482-2236A) (40.7%) and completely wild-type (C_G_C_G) (39.5%) haplotypes prevailed, and had a closely similar prevalence of cases: 21.1% vs. 23.1%, respectively.

Conclusions

The evaluated common ABCB1 polymorphisms do not seem to affect the risk of early bleeding in patients started on rivaroxaban.

Risk of bleeding with concomitant use of oral anticoagulants and aspirin: A systematic review and meta-analysis

PURPOSE

Oral anticoagulants (OACs) and aspirin can trigger bleeding events when used alone or in combination. The purpose of this study was to compare the risk of any type of bleeding in individuals exposed to a combination of OAC and aspirin with the risk in those taking an OAC or aspirin alone.

METHODS

MEDLINE and Web of Science were queried in January 2021 for eligible articles. Studies were included if they were either randomized controlled trials (RCTs) or observational studies and evaluated the number of any bleeding events in two groups, one with exposure to both OAC and aspirin and one with exposure to OAC alone or aspirin alone. Pooled odds ratios were calculated using a random-effects model.

RESULTS

Forty-two studies were included. In an analysis of 15 RCTs and 19 observational studies evaluating OAC plus aspirin versus OAC alone, a significant difference in the risk of bleeding was observed in the combination groups, with an odds ratio [OR] of, 1.36 (95% CI, 1.15-1.59) for RCTs and an OR of 1.42 (95% CI-, 1.09-1.87) for observational studies. When OAC plus aspirin was compared to aspirin alone, a higher rate of bleeding was found in the combination group (OR, 2.36; 95%CI, 1.91-2.92) in the analysis of 15 RCTs, but no significant difference was found among 10 observational studies (OR, 1.93; 95% Cl, 0.99-3.75).

CONCLUSION

The risk of any type of bleeding was significantly increased among patients taking aspirin plus OAC compared to those taking OAC alone in both RCTs and observational studies. Evaluation of RCTs comparing OAC plus aspirin to aspirin alone suggests increased bleeding risk as well.

Carbonization of quercetin into nanogels: a leap in anticoagulant development

Quercetin, a flavonoid abundantly found in onions, fruits, and vegetables, is recognized for its pharmacological potential, especially for its anticoagulant properties that work by inhibiting thrombin and coagulation factor Xa. However, its clinical application is limited due to poor water solubility and bioavailability. To address these limitations, we engineered carbonized nanogels derived from quercetin (CNGsQur) using controlled pyrolysis and polymerization techniques. This led to substantial improvements in its anticoagulation efficacy, water solubility, and biocompatibility. We generated a range of CNGsQur by subjecting quercetin to varying pyrolytic temperatures and then assessed their anticoagulation capacities both in vitro and in vivo. Coagulation metrics, including thrombin clotting time (TCT), activated partial thromboplastin time (aPTT), and prothrombin time (PT), along with a rat tail bleeding assay, were utilized to gauge the efficacy. CNGsQur showed a pronounced extension of coagulation time compared to uncarbonized quercetin. Specifically, CNGsQur synthesized at 270 °C (CNGsQur270) exhibited the most significant enhancement in TCT, with a binding affinity to thrombin exceeding 400 times that of quercetin. Moreover, variants synthesized at 310 °C (CNGsQur310) and 290 °C (CNGsQur290) showed the most substantial delays in PT and aPTT, respectively. Our findings indicate that the degree of carbonization significantly influences the transformation of quercetin into various CNGsQur forms, each affecting distinct coagulation pathways. Additionally, both intravenous and oral administrations of CNGsQur were found to extend rat tail bleeding times by up to fivefold. Our studies also demonstrate that CNGsQur270 effectively delays and even prevents FeCl3-induced vascular occlusion in a dose-dependent manner in mice. Thus, controlled pyrolysis offers an innovative approach for generating quercetin-derived CNGs with enhanced anticoagulation properties and water solubility, revealing the potential for synthesizing self-functional carbonized nanomaterials from other flavonoids for diverse biomedical applications.

Role of Clinical Pharmacy anticoagulation service on Apixaban prescribing appropriateness in atrial fibrillation in Saudi Arabia

BACKGROUND

Inappropriate DAOC dosing is precuarious and frequently encountered. Apixaban is the most reported DOAC to be inappropriately dosed. We examined the effect of adding a Clinical Pharmacist to the cardiology team rounds to the standard practice in Apixaban prescription patterns in a tertiary center in KSA.

OBJECTIVE

To determine the effect of clinical pharmacy services on Apixaban dose appropriateness upon discharge in Atrial Fibrillation patient pobulation.

METHODS

This is a single-center, retrospective cohort of patients with atrial fibrillation using a quasi-experiment of pre-post design to evaluate Apixaban dose appropriateness using clinical pharmacy services. Clinical pharmacist was added to the team to evaluate and change the regimen according to FDA dosing. Data were collected for 9 months for each, patients were followed up for efficacy and safety outcomes for 1 year.

RESULTS

A total of 550 patients were initially collected after follow-up, the number of patients was in the pre-phase cohort (NO CCP; n= 112) from July 2018 to the March 2019 and compared to post phase cohort (CCP, n=103) from July 2019 to March 2020. 215 Patients were included, For primary end point, CCP cohort had significantly appropriate prescriptions of apixaban compared to Non-CCP (90.2 % vs 71.5 %, p<0.001)., no differences in thromboembolic and hemorrhagic adverse events betewwn 2 cohorts.

CONCLUSION

A multidisciplinary team approach including clinical pharmacy services is effective in increasing the appropriate use of Apixaban upom discharge without apparent increased risk of bleeding or Adverse events.

Epidemiology and outcomes of intracerebral hemorrhage associated with oral anticoagulation over 10 years in a population-based stroke registry

BACKGROUND

Recent years have seen a change in the use of anticoagulants in the general population due to the availability of direct oral anticoagulants (DOACs) as an alternative to vitamin K antagonists (VKAs) and increased detection of atrial fibrillation. It is important to have updated epidemiological data to understand how this change is impacting on the occurrence and outcome of intracerebral hemorrhage (ICH).

PATIENTS AND METHODS

Our prospective population-based registry included patients with first-ever ICH occurring from January 2011 to December 2020. Oral anticoagulants (OAC)-related ICH was defined as an ICH occurring within 48 h from the intake of DOAC or VKAs, regardless of the measured international normalized ratio on hospital admission.

RESULTS

We included 748 first-ever ICH, of whom 108 (14.4%) were OAC-related. Specifically, 75 (69.4%) ICHs occurred on VKA and 33 (30.6%) on DOAC. The incidence of oral anticoagulation-associated intracerebral hemorrhage (OAC-ICH) was stable over time (p = 0.226). Among OAC-ICHs, we observed an increase in the overall incidence of DOAC-ICH (p for trend < 0.001) which overcome that of VKA-ICH in 2020 (incidence rate ratio (IRR) 4.71, 95% confidence interval (CI): 1.22-33.54; p = 0.022). Patients with OAC-ICH showed higher 30-day case fatality rates than those with non-OAC-ICH (48.1% vs 34.1%; p = 0.007).

CONCLUSION

No changes over time were detected in the incidence of OAC-ICH, but throughout the study period, there was a change in OAC-ICH from mostly VKA-related to mostly DOAC-related. Mortality in patients with OAC-ICH was higher than in patients with non-OAC-ICH.

Risk of stroke in patients with prior VKA or DOAC: A population-based real-world registry analysis

INTRODUCTION

To date, risk assessment of suffering ischemic and hemorrhagic stroke in individuals under oral anticoagulation (OAC) is limited to hospital-based cohorts and patients with atrial fibrillation.

PATIENTS AND METHODS

Through the combination of three individual datasets, (1) the population-based Tyrolean Stroke Pathway database, prospectively documenting all (unselected) stroke patients in the entire federal state of the Tyrol and (2) nation-wide prescription data, detailing each reimbursed prescription in Austria as well as (3) the Austrian Stroke Unit Registry, a nation-wide registry comprising data on all patients admitted to any of the 38 stroke units in Austria, we assessed risk of stroke in patients with prior oral anticoagulation and compared characteristics of patients taking direct oral anticoagulants and Vitamin-K-Antagonists.

RESULTS

In Austria, oral anticoagulant prescription reimbursements increased from 292,475 in 2015 to 389,407 in 2021. In the Tyrol, prior oral anticoagulation treatment was evident in 586 of 3861 (15.2%) patients with ischemic and 131 of 523 (25.0%) with hemorrhagic stroke, with 20% and 35% of those stroke patients respectively having prior oral anticoagulation due to other indications than non-valvular atrial fibrillation. Considering prescription rates, treatment with direct oral anticoagulants was associated with a reduced stroke risk compared to Vitamin-K-Antagonists, especially in ischemic (1.05% vs 0.62%; RR 0.59, p < 0.001) but also in hemorrhagic stroke, even if less pronounced (0.21% vs 0.14%; RR 0.68, p = 0.06). In Austria, prior intake of direct oral anticoagulants was associated with lower risk of suffering acute large vessel occlusion stroke (RR 0.79, p = 0.003).

DISCUSSION AND CONCLUSIONS

One in seven patients suffering ischemic and one in four suffering hemorrhagic stroke had prior oral anticoagulation treatment. Both ischemic and hemorrhagic strokes are less frequent in those with direct oral anticoagulant intake compared to those taking Vitamin-K-Antagonists. Establishment of clear standard operating procedures on how to best care for acute stroke patients with oral anticoagulation is essential.

Uninterrupted direct-acting oral anticoagulation in patients undergoing transradial percutaneous coronary procedures: The DOAC-NOSTOP study rationale and design

BACKGROUND

patients with atrial fibrillation (AF) under treatment with chronic oral anticoagulation (OAC) often require coronary angiography with or without percutaneous coronary intervention (PCI). Deciding the management of OAC during this periprocedural period requires balancing the risks of hemorrhage and thrombotic complications. Guidelines recommend an uninterrupted strategy in patients receiving Vitamin-K Antagonists (VKA). However, for patients undergoing coronary angiography or PCI while on direct oral anticoagulants (DOACs), withdrawal 12-24 h prior to the procedure is still recommended. This is based on expert opinions given the lack of evidence. Therefore, whether DOAC discontinuation prior to trans-radial coronary procedures should be the strategy of choice is a matter of debate and solid evidence is needed to guide clinical decision making.

METHODS

The DOAC-NOSTOP study is a prospective, single-arm, open-label study evaluating the safety of DOACs continuation in 200 patients undergoing transradial percutaneous coronary procedures. DOAC treatment will not be interrupted throughout the periprocedural period. Primary outcome will be Bleeding Academic Research Consortium (BARC) type 2, 3, or 5 events, assessed at a 30-day follow-up.

CONCLUSIONS

The DOAC-NOSTOP is the first study prospectively assessing the risk of bleeding with uninterrupted DOAC in patients undergoing trans-radial percutaneous coronary procedures.

Direct Oral Anticoagulants: Navigating Through Clinical Challenges

PURPOSE

Direct oral anticoagulants (DOACs) have been approved, for over a decade, by both European and American medicine agencies, for treatment and prevention of several cardiovascular conditions. Since then, an increasing amount of data has been added to the medical literature day by day, resulting in a dichotomy in selection of the appropriate agent, dosage, and duration of treatment for special populations with multiple comorbidities. Considering these issues, we have prepared a comprehensive review for the clinical practitioner, to optimize the DOAC utilization in clinical practice.

METHODS

A thorough literature search and review was conducted, concerning mainly the last decade. Our review focused on the current guidelines and the most recently published studies in PubMed, Science Direct Scopus, and Google Scholar to date.

CONCLUSION

The purpose of this study is to provide guidance for healthcare professionals for making proper decisions when confronted with clinical challenges. Nevertheless, further research is required to establish DOAC superiority in complicated cases, where there is clinical uncertainty.

Role of anticoagulation in non-ST-elevation myocardial infarction: a contemporary narrative review

INTRODUCTION

Anticoagulants play a vital role as part of the antithrombotic therapy of myocardial infarction and are complementary to antiplatelet therapies. In the acute setting, the rationale for their use is to antagonize the ongoing clotting cascade including during percutaneous coronary intervention. Anticoagulation may be an important part of the longer-term antithrombotic strategy especially in patients who have other existing indications (e.g. atrial fibrillation) for their use.

AREAS COVERED

In this narrative review, the authors provide a contemporary summary of the anticoagulation strategies of patients presenting with NSTEMI, both in terms of anticoagulation during the acute phase as well as suggested antithrombotic regimens for patients who require long-term anticoagulation for other indications.

EXPERT OPINION

Patients presenting with non-ST-elevation myocardial infarction (NSTEMI) should be initiated on anticoagulation (e.g. heparin/low molecular weight heparin) for the initial hospitalization period for those medically managed or until percutaneous coronary intervention. Longer term management of NSTEMI for patients with an existing indication for long-term anticoagulation should comprise triple antithrombotic therapy of anticoagulant (preferably DOAC) with aspirin and clopidogrel for up to 1 month (typically 1 week or until hospital discharge), followed by DOAC plus clopidogrel for up to 1 year, and then DOAC monotherapy thereafter.

Head-to-head ex vivo comparison of clinically used direct anticoagulant drugs

An imbalance in coagulation is associated with cardiovascular events. For prevention and treatment, anticoagulants, currently mainly xabans and gatrans, are used. The purpose of the present study was to provide a head-to-head comparison since there are no studies directly evaluating these novel anticoagulants. An additional aim was to find whether selected anthropological and biochemical factors can affect their anticoagulant properties as they are used in fixed doses. In this cross-sectional study, blood from 50 generally healthy donors was collected, and coagulation responses to dabigatran, argatroban, rivaroxaban, and apixaban, at a concentration of 1 μM, were analyzed. Heparin was used as a positive control. Prothrombin time (PT) expressed as international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were measured and compared. Rivaroxaban was the most active according to PT/INR while argatroban according to aPTT. The ex vivo anticoagulant effect measured by INR correlated inversely with body mass index (BMI) in all four anticoagulants tested. Shortening of aPTT was associated with higher cholesterol and triglyceride levels. No sex-related differences were observed in response to the anticoagulant treatments. As this was an ex vivo study and pharmacokinetic factors were not included, the influence of BMI is of high therapeutic importance.

Perioperative Management of Valvular Heart Disease in Patients Undergoing Non-Cardiac Surgery

Postoperative cardiovascular complications (either in a hospital or within 30 days after the operation) are among the most common problems with non-cardiac surgeries (NCSs). Pre-existing cardiac comorbidities add significant risk to the development of such complications. Valvular heart disease (VHD), a rather frequent cardiac comorbidity (especially in the elderly population), can pose serious life-threatening peri-/postoperative complications. Being familiar with the recommended perioperative management of patients with VHD or an implanted prosthetic heart valve who are scheduled for NCS is of great importance in daily clinical practice. Although recently published guidelines by the European Society of Cardiology (ESC) and the American College of Cardiology and American Heart Association (ACC/AHA) for the management of VHD and perioperative management of patients undergoing NCS addresses the mentioned problem, a comprehensive review of the guidelines that provides an easy-to-use summary of the recommendations and their similarities and differences is missing in the published literature. In this review article, we summarize all of the relevant important information based on the latest data published in both guidelines needed for practical decision-making in the perioperative management of patients with VHD or after valvular repair (with prosthetic heart valve) who are scheduled for NCS.

Machine Learning - Based Bleeding Risk Predictions in Atrial Fibrillation Patients on Direct Oral Anticoagulants

Importance

Accurately predicting major bleeding events in non-valvular atrial fibrillation (AF) patients on direct oral anticoagulants (DOACs) is crucial for personalized treatment and improving patient outcomes, especially with emerging alternatives like left atrial appendage closure devices. The left atrial appendage closure devices reduce stroke risk comparably but with significantly fewer non-procedural bleeding events.

Objective

To evaluate the performance of machine learning (ML) risk models in predicting clinically significant bleeding events requiring hospitalization and hemorrhagic stroke in non-valvular AF patients on DOACs compared to conventional bleeding risk scores (HAS-BLED, ORBIT, and ATRIA) at the index visit to a cardiologist for AF management.

Design

Prognostic modeling with retrospective cohort study design using electronic health record (EHR) data, with clinical follow-up at one-, two-, and five-years.

Setting

University of Pittsburgh Medical Center (UPMC) system.

Participants

24,468 non-valvular AF patients aged ≥18 years treated with DOACs, excluding those with prior history of significant bleeding, other indications for DOACs, on warfarin or contraindicated to DOACs.

Exposures

DOAC therapy for non-valvular AF.

Main Outcomes and Measures

The primary endpoint was clinically significant bleeding requiring hospitalization within one year of index visit. The models incorporated demographic, clinical, and laboratory variables available in the EHR at the index visit.

Results

Among 24,468 patients, 553 (2.3%) had bleeding events within one year, 829 (3.5%) within two years, and 1,292 (5.8%) within five years of index visit. We evaluated multivariate logistic regression and ML models including random forest, classification trees, k-nearest neighbor, naive Bayes, and extreme gradient boosting (XGBoost) which modestly outperformed HAS-BLED, ATRIA, and ORBIT scores in predicting clinically significant bleeding at 1-year follow-up. The best performing model (random forest) showed area under the curve (AUC-ROC) 0.76 (0.70-0.81), G-Mean score of 0.67, net reclassification index 0.14 compared to 0.57 (0.50-0.63), G-Mean score of 0.57 for HASBLED score, p-value for difference <0.001. The ML models had improved performance compared to conventional risk across time-points of 2-year and 5-years and within the subgroup of hemorrhagic stroke. SHAP analysis identified novel risk factors including measures from body mass index, cholesterol profile, and insurance type beyond those used in conventional risk scores.

Conclusions and Relevance

Our findings demonstrate the superior performance of ML models compared to conventional bleeding risk scores and identify novel risk factors highlighting the potential for personalized bleeding risk assessment in AF patients on DOACs.

Changes in Time in Therapeutic Range Within a Warfarin Anticoagulation Clinic Following Introduction of Direct Oral Anticoagulants

Background: As direct oral anticoagulants (DOACs) have become widely recommended as first-line anticoagulation therapy, patients who remain on warfarin are likely those unable to afford, adhere to, or utilize DOAC therapy due to the presence of a contraindication. It is currently unknown how availability of DOACs have affected populations being managed at warfarin (VKA) anticoagulation clinics. Methods: This was a retrospective chart review assessing warfarin-treated patients at an outpatient anticoagulation clinic. The primary endpoint was the 6-month time in therapeutic range (TTR) before and after DOACs were recommended as first-line therapy by clinical guidelines. Study periods were January to June 2015, before DOACs were recommended over VKA, and January to June 2022, when DOACs were often recommended over VKA. TTR, demographic changes, and the presence of contraindications to DOAC therapy in the clinic population between the two time periods were assessed. Results: No difference in 6-month TTR was observed between study periods (59% in 2015 vs 63% in 2022; P = .45). Patient demographics did not significantly vary, which may be due to the clinic retaining 45% of patients between both time periods. Contraindications to DOAC therapy were identified in 39% of the 2015 group and 49% of the 2022 group (P = .18). The most common contraindication was indication for anticoagulation. Conclusion: Availability of DOACs did not seem to significantly affect the population or management of warfarin-treated patients at an outpatient anticoagulation clinic, however, contraindications and potential challenges to use of DOAC therapy are present in many patients.

Factor XI as a new target for prevention of thromboembolism in cardiovascular disease: a meta-analysis of randomized controlled trials

Anticoagulant therapy is a mainstay in the management of patients with cardiovascular disease. The use of conventional anticoagulants carries potential side effects, mainly bleeding. Drugs targeting Factor XI (FXI) have been investigated in randomized controlled trials as a new option with more favorable outcomes. A comprehensive literature search was conducted to identify relevant studies comparing FXI inhibitors to placebo or standard therapy. The primary outcomes were incidence of all bleeding events, major bleeding, and thromboembolism. Secondary outcomes included incidence of all adverse events (AE), serious AE, and all-cause mortality. A total of 11 studies involving 10,536 patients were included. FXI inhibitors were associated with a trend toward reduction of bleeding events and incidence of thromboembolism compared to the control group (placebo/standard therapy). There was no statistically significant difference between both groups in terms of adverse events and all-cause mortality. When compared to enoxaparin, FXI inhibitors significantly reduced the risk of bleeding events (RR = 0.42, 95% CI: 0.23-0.76, P = 0.004) and thromboembolism (RR = 0.59, 95% CI: 0.44-0.77, P = 0.001). On the other hand, when compared to DOACs, FXI inhibitors were associated with a significant reduction in bleeding events but not thromboembolism. Whereas, compared to placebo, FXI inhibitors did not increase the risk of bleeding events, adverse events, or all-cause mortality (P > 0.05). FXI inhibitors could be a safer and more potent option for prevention of thromboembolism than conventional therapy.

Comparing clinical outcomes of vitamin K antagonists vs non-vitamin K antagonists in anticoagulant therapy for mesenteric venous thrombosis

OBJECTIVE

Non-vitamin K antagonist oral anticoagulants have shown similar efficacy and lower bleeding rates than vitamin K antagonists for venous thromboembolism. However, this has not been proven in mesenteric vein thrombosis. This study aimed to compare the clinical outcomes of vitamin K antagonists and non-vitamin K antagonist oral anticoagulants.

METHODS

Between January 2014 and July 2022, mesenteric vein thrombosis was diagnosed on computed tomography in 225 patients in a tertiary hospital. Among them, a total of 44 patients who underwent long-term anticoagulation therapy over 3 months were enrolled in this study. Patients were divided into two groups based on the anticoagulant used: vitamin K antagonists (Group 1, n = 21) and non-vitamin K antagonist oral anticoagulants (Group 2, n = 23). The efficacy outcomes were symptom recurrence and thrombus resolution on follow-up computed tomography, and the safety outcome was bleeding complications.

RESULTS

The median age of the patients was 56 years (range, 46-68 years), and 52% were men. The most common risk factors were unprovoked intra-abdominal infections (30%). The median duration of anticoagulation therapy was 13 months (20 months in Group 1 vs 6 months in Group 2; P = .076). Of the 44 patients, 17 (39%) received the standard treatment. The median follow-up period was longer in Group 1 than in Group 2 (57 vs 28 months; P = .048). No recurrence of mesenteric vein thrombosis-related symptoms were observed in either group. The median duration of follow-up computed tomography was 31 months (42 months in Group 1 vs 18 months in Group 2; P = .064). Computed tomography revealed complete thrombus resolution, partial resolution, and no changes in 71%, 19%, and 10%, respectively (P = .075). Regarding bleeding complications, varix bleeding and melena developed in two patients in Group 2, and anticoagulation treatment thereafter ceased.

CONCLUSIONS

Despite the short follow-up duration in the non-vitamin K antagonist oral anticoagulants group, there was no clinically significant difference in the thrombus resolution rate or bleeding complications when compared with the vitamin K antagonists group. Although research on the long-term effects of non-vitamin K antagonist oral anticoagulants in patients is limited, non-vitamin K antagonist oral anticoagulants can be considered an alternative to conventional treatments.

Engineering and evaluation of FXa bypassing agents that restore hemostasis following Apixaban associated bleeding

Direct oral anticoagulants (DOACs) targeting activated factor Xa (FXa) are used to prevent or treat thromboembolic disorders. DOACs reversibly bind to FXa and inhibit its enzymatic activity. However, DOAC treatment carries the risk of anticoagulant-associated bleeding. Currently, only one specific agent, andexanet alfa, is approved to reverse the anticoagulant effects of FXa-targeting DOACs (FXaDOACs) and control life-threatening bleeding. However, because of its mechanism of action, andexanet alfa requires a cumbersome dosing schedule, and its use is associated with the risk of thrombosis. Here, we present the computational design, engineering, and evaluation of FXa-variants that exhibit anticoagulation reversal activity in the presence of FXaDOACs. Our designs demonstrate low DOAC binding affinity, retain FXa-enzymatic activity and reduce the DOAC-associated bleeding by restoring hemostasis in mice treated with apixaban. Importantly, the FXaDOACs reversal agents we designed, unlike andexanet alfa, do not inhibit TFPI, and consequently, may have a safer thrombogenic profile.

Pharmacological and clinical appraisal of factor XI inhibitor drugs

The evolution of anticoagulation therapy, from vitamin K antagonists to the advent of direct oral anticoagulants (DOACs) almost two decades ago, marks significant progress. Despite improved safety demonstrated in pivotal trials and post-marketing observations, persistent concerns exist, particularly regarding bleeding risk and the absence of therapeutic indications in specific subgroups or clinical contexts. Factor XI (FXI) has recently emerged as a pivotal contributor to intraluminal thrombus formation and growth, playing a limited role in sealing vessel wall injuries. Inhibiting FXI presents an opportunity to decouple thrombosis from haemostasis, addressing concerns related to bleeding events while safeguarding against thromboembolic events. Notably, FXI inhibition holds promise for patients with end-stage renal disease or cancer, where clear indications for DOACs are currently lacking. Various compounds have undergone design, testing, and progression to phase 2 clinical trials, demonstrating a generally favourable safety and tolerability profile. However, validation through large-scale phase 3 trials with sufficient power to assess both safety and efficacy outcomes is needed. This review comprehensively examines FXI inhibitors, delving into individual classes, exploring their pharmacological properties, evaluating the latest evidence from randomized trials, and offering insights into future perspectives.

Predictors of adherence to direct oral anticoagulants after cardiovascular or bleeding events in Medicare Advantage Plan enrollees with atrial fibrillation

BACKGROUND

Direct oral anticoagulants (DOACs) are recommended for patients with atrial fibrillation (AF) given their improved safety profile. Suboptimal adherence to DOACs remains a significant concern among individuals with AF. However, the extent of adherence to DOACs following a cardiovascular or bleeding event has not been fully evaluated.

OBJECTIVE

To evaluate the pattern of adherence trajectories of DOACs after a cardiovascular or bleeding event and to investigate the sociodemographic and clinical predictors associated with each adherence trajectory by using claims-based data.

METHODS

This retrospective study was conducted among patients with AF prescribed with DOACs (dabigatran/apixaban/rivaroxaban) between July 2016 and December 2017 and who were continuously enrolled in the Texas-based Medicare Advantage Plan. Patients who experienced a cardiovascular or bleeding event while using the DOACs were further included in the analysis. The sample was limited to patients who experienced a clinical event such as a cardiovascular or bleeding event while using the DOACs. The clinical events considered in this study were cardiovascular (stroke, congestive heart failure, myocardial infarction, systemic embolism) and bleeding events. To assess adherence patterns, each patient with a DOAC prescription was followed up for a year after experiencing a clinical event. The monthly adherence to DOACs after these events was evaluated using the proportion of days covered (PDC). A group-based trajectory model incorporated the monthly PDC to classify groups of patients based on their distinct patterns of adherence. Predictors associated with each trajectory were assessed using a multinomial logistic regression model, with the adherent trajectory serving as the reference group in the outcome variable.

RESULTS

Among the 694 patients with AF who experienced clinical events after the initiation of DOACs, 3 distinct adherence trajectories were identified: intermediate nonadherent (30.50%), adherent (37.7%), and low adherent (31.8%); the mean PDC was 0.47 for the intermediate nonadherent trajectory, 0.93 for the adherent trajectory, and 0.01 for low adherent trajectory. The low-income subsidy was significantly associated with lower adherence trajectories (odds ratio [OR] = 4.81; 95% CI = 3.07-7.51) and with intermediate nonadherent trajectories (OR = 1.57; 95% CI = 1.06-2.34). Also, nonsteroidal anti-inflammatory drug use was significantly associated with lower adherence trajectories (OR = 5.10; 95% CI = 1.95-13.36) and intermediate nonadherent trajectories (OR = 3.17; 95% CI = 1.26-7.93). Other predictors significantly associated with both nonadherent trajectories are type of DOACs (OR = 0.53; 95% CI = 0.35-0.79), presence of coronary artery disease (OR = 1.89; 95% CI = 1.01-3.55), and having 2 or more clinical events (OR = 1.65; 95% CI = 1.09-2.50).

CONCLUSIONS

Predictors identified provide valuable insights into the suboptimal adherence of DOACs among Medicare Advantage Plan enrollees with AF, which can guide the development of targeted interventions to enhance adherence in this high-risk patient population.

Development of immediate-release formulation with reliable absorption of rivaroxaban in various meal regimes

The bioavailability of rivaroxaban at the higher doses (15 and 20 mg) is considerably reduced when the drug is administered on an empty stomach. This can lead to inadequate anticoagulant effect, and therefore, it is recommended to use the higher doses at fed state. However, proper posology may represent a barrier for some patients. Therefore, the aim of this study was to evaluate innovative rivaroxaban-containing formulations designed to eliminate the food effect to ensure reliable absorption and thus to improve patient adherence with the treatment. Three prototypes (Cocrystal, HPMCP and Kollidon) with rivaroxaban were developed and their bioavailability and food effect in comparison to the reference product was tested in open label, randomized, single oral dose, crossover studies, where test products were administered under fasting and fed conditions and the reference product was administered under fed conditions. Comparable bioavailability for all tested prototypes both under fed and fasting conditions was demonstrated as the 90% confidence intervals of the geometric mean ratios for area under the concentration-time curve remained within the standard acceptance range of 80.00%-125.00%. An innovative immediate release form of rivaroxaban with no food effect on drug bioavailability has been developed, which may represent an important step toward increasing adherence, improving treatment outcome and reducing health care costs.

Emulation of randomized trials of direct oral anticoagulants with claims data and implications for new Factor XI inhibitors

Direct oral anticoagulants (DOACs) revolutionized the management of thromboembolic disorders. Clinical care may be further improved as Factor XIs undergo large-scale outcome trials. What role can non-randomized database studies play in expediting understanding of these drugs in clinical practice? The RCT-DUPLICATIVE Initiative emulated the design of eight DOAC randomized clinical trials (RCT) using non-randomized claims database studies. RCT study design parameters and measurements were closely emulated by the database studies and produced highly concordant results. The results of the single database study that did not meet all agreement metrics with the specific RCT it was emulating were aligned with a meta-analysis of six trials studying similar questions, suggesting the trial result was an outlier. Well-designed database studies using fit-for-purpose data came to the same conclusions as DOAC trials, illustrating how database studies could complement RCTs for Factor XI inhibitors-by accelerating insights in underrepresented populations, demonstrating effectiveness and safety in clinical practice, and testing broader indications.

Racial and Ethnic Disparities in Initiation of Direct Oral Anticoagulants Among Medicare Beneficiaries

Importance

The influence of race and ethnicity on initiation of direct oral anticoagulants (DOACs) is relatively understudied in Medicare data.

Objective

To investigate disparities in the initiation of DOACs compared with warfarin by race, ethnicity, and social vulnerability.

Design, Setting, and Participants

This retrospective cohort study used a 50% sample of Medicare fee-for-service data from January 1, 2010, to December 31, 2019 (mean patient enrollment duration, 7.7 years). Analysis took place between January 2023 and February 2024. A cohort of older adults (aged ≥65 years) with atrial fibrillation who newly initiated warfarin or DOACs (dabigatran, rivaroxaban, apixaban, and edoxaban) was identified.

Exposure

Patients were classified as non-Hispanic White, non-Hispanic Black, and Hispanic.

Main Outcomes and Measures

The likelihood of starting use of DOACs compared with warfarin was modeled, adjusting for race, ethnicity, age, sex, county-level social vulnerability, and other clinical factors.

Results

Among 950 698 anticoagulation initiations, consisting of 680 974 DOAC users and 269 724 warfarin users (mean [SD] age, 78.5 [7.6] years; 52.6% female), 5.2% were Black, 4.3% were Hispanic, and 86.7% were White. During the 10-year study period, DOAC use increased for all demographic groups. After adjustment, compared with White patients, Black patients were 23% less likely (adjusted odds ratio [AOR, 0.77; 95% CI, 0.75-0.79) and Hispanic patients were 13% less likely (AOR, 0.87; 95% CI, 0.85-0.89) to initiate DOAC use. Disparities in DOAC initiation were greatest among Black patients in the earlier years but attenuated during the study period. For instance, in 2010, the OR of Black patients initiating DOACs was 0.54 (95% CI, 0.50-0.57), attenuating linearly over time to 0.69 by 2013 (95% CI, 0.65-0.74) and 0.83 (95% CI, 0.78-0.89) by 2017. By 2019, these differences became nonsignificant (OR, 1.08; 95% CI, 0.99-1.18).

Conclusions and Relevance

In this cohort study of Medicare patients with atrial fibrillation, Black and Hispanic patients were less likely to initiate DOACs for atrial fibrillation, although these differences diminished over time. Identifying the factors behind these early disparities is crucial for ensuring equitable access to novel therapies as they emerge for Black and Hispanic populations.

Practical guidance for direct oral anticoagulant use in the treatment of venous thromboembolism in primary and metastatic brain tumor patients

Management of venous thromboembolism (VTE) in patients with primary and metastatic brain tumors (BT) is challenging because of the risk of intracranial hemorrhage (ICH). There are no prospective clinical trials evaluating safety and efficacy of direct oral anticoagulants (DOACs), specifically in patients with BT, but they are widely used for VTE in this population. A group of neuro-oncology experts convened to provide practical clinical guidance for the off-label use of DOACs in treating VTE in patients with BT. We searched PubMed for the following terms: BTs, glioma, glioblastoma (GBM), brain metastasis, VTE, heparin, low-molecular-weight heparin (LWMH), DOACs, and ICH. Although prospective clinical trials are needed, the recommendations presented aim to assist clinicians in making informed decisions regarding DOACs for VTE in patients with BT.

How to explain the beneficial effects of platelet-rich plasma

Platelet-rich plasma (PRP) is the platelet and leukocyte-containing plasmatic fraction of anticoagulated autologous blood. While evidence supporting the clinical use of PRP in dentistry is low, PRP is widely used in sports medicine, orthopedics, and dermatology. Its beneficial activity is commonly attributed to the growth factors released from platelets accumulating in PRP; however, evidence is indirect and not comprehensive. There is thus a demand to revisit PRP with respect to basic and translational science. This review is to (i) recapitulate protocols and tools to prepare PRP; (ii) to discuss the cellular and molecular composition of PRP with a focus on platelets, leukocytes, and the fibrin-rich extracellular matrix of coagulated plasma; and finally (iii) to discuss potential beneficial effects of PRP on a cellular and molecular level with an outlook on its current use in dentistry and other medical fields.

A real-world exploration into clinical outcomes of direct oral anticoagulant therapy in people with chronic kidney disease: a large hospital-based study

BACKGROUND

There is limited evidence to support definite clinical outcomes of direct oral anticoagulant (DOAC) therapy in chronic kidney disease (CKD). By identifying the important variables associated with clinical outcomes following DOAC administration in patients in different stages of CKD, this study aims to assess this evidence gap.

METHODS

An anonymised dataset comprising 97,413 patients receiving DOAC therapy in a tertiary health setting was systematically extracted from the multidimensional electronic health records and prepared for analysis. Machine learning classifiers were applied to the prepared dataset to select the important features which informed covariate selection in multivariate logistic regression analysis.

RESULTS

For both CKD and non-CKD DOAC users, features such as length of stay, treatment days, and age were ranked highest for relevance to adverse outcomes like death and stroke. Patients with Stage 3a CKD had significantly higher odds of ischaemic stroke (OR 2.45, 95% Cl: 2.10-2.86; p = 0.001) and lower odds of all-cause mortality (OR 0.87, 95% Cl: 0.79-0.95; p = 0.001) on apixaban therapy. In patients with CKD (Stage 5) receiving apixaban, the odds of death were significantly lowered (OR 0.28, 95% Cl: 0.14-0.58; p = 0.001), while the effect on ischaemic stroke was insignificant.

CONCLUSIONS

A positive effect of DOAC therapy was observed in advanced CKD. Key factors influencing clinical outcomes following DOAC administration in patients in different stages of CKD were identified. These are crucial for designing more advanced studies to explore safer and more effective DOAC therapy for the population.

Management of patients with proximal femur fractures under DOACs

PURPOSE

In the past, preinjury direct oral anticoagulant (DOAC) intake has led to delays in time to surgery (TTS) in patients with proximal femur fractures and delays in surgery have been associated with impaired outcomes. Although healthcare institutions/federal committees have set rules for treatment within 24 h of injury, comprehensive guidelines for the perioperative management of these patients, in particular when on preinjury DOACs, are still lacking. This contribution aims to summarize the current evidence on the safe time window for surgery in patients with proximal femur fractures on preinjury DOACs and to outline therapeutic options if emergency DOAC reversal becomes necessary.

METHODS

Narrative review based upon selective review of the pertinent literature.

RESULTS

For the majority of patients with proximal femur fractures and on preinjury DOACs, early surgery appears safe as soon as medical clearance has been obtained. There may be an increase in the need for blood products but with data not yet conclusive. Work-up including assessment of remaining anticoagulant activity and potential reversal should be restricted to patients at risk for bleeding complications, in particular in the presence of renal/hepatic impairment. Methodology for rapid assessment of DOACs including quantitative/qualitative concentration levels is work in progress. In the case of bleeding, rapidly acting reversal agents are available.

CONCLUSION

Preinjury DOAC use should not routinely delay surgery in patients with proximal femur fractures.

Comparative Effectiveness and Safety of Direct Oral Anticoagulants Compared with Warfarin in Patients with Low Bodyweight who have Atrial Fibrillation: A Systematic Review and Meta-analysis

INTRODUCTION

oral anticoagulant (DOAC) agents are becoming the anticoagulation strategy of choice for most clinical risks for which they are indicated. However, residual uncertainty remains regarding their use in preventing stroke in patients with low bodyweight [< 60 kg or body mass index (BMI) < 18 kg/m2]. We have carried out pooled systematic analyses of published studies to determine the efficacy and safety of these agents compared with warfarin in stroke prevention in patients with low bodyweight.

METHODS

We carried out a comprehensive search of electronic databases from inception to June 2023 for eligible studies reporting on the efficacy and safety of direct oral anticoagulants versus warfarin in patients with atrial fibrillation who had low bodyweight. These include PubMed, EMBASE, the Cochrane Database of Systematic Reviews, the Science Citation Index, and the Database of Abstracts of Reviews of Effectiveness. Using the random effects model, derived pooled odd ratios (with their corresponding confidence intervals) of mortality outcomes in patient cohorts exposed to direct oral anticoagulants versus warfarin in patients with atrial fibrillation who had low bodyweight.

RESULTS

Nine studies (n = 159,514 patients) were included in our meta-analysis. DOAC analogs were associated with lower stroke recurrence compared with warfarin [odds ratio (OR) 0.66, 95% confidence interval (CI) 0.49-0.9]; however, there was no significant difference in the composite outcome (OR 0.81, 95% CI 0.59-1.09) and mortality (OR 0.82, 95% CI 0.48-1.41). Additionally, DOAC analogs showed a significant reduction in major bleeding events by 30% compared with warfarin (OR 0.70, 95% CI 0.62-0.80).

CONCLUSION

In this pooled meta-analytical synthesis of studies comprising both real-world and randomized controlled data, the use of DOAC analogs in patients with atrial fibrillation and low bodyweight (< 60 kg or BMI < 18 kg/m2) was associated with a significant reduction in risks of stroke and major bleeding compared with patient cohorts stabilized on warfarin-based therapy. There was uncertainty regarding the composite outcome and mortality point estimate between these two anticoagulation strategies. This finding helps to resolve the uncertainty associated with the use of DOACs in this cohort. Additionally, it suggests the need for confirmatory non-inferiority randomized controlled trials evaluating DOACs versus warfarin in this cohort of patients.

Complex management of pulmonary embolism in APLA syndrome: a case study of ECMO and bivalirudin utilization

We report a case of a 22-year-old female with antiphospholipid antibody (APLA) syndrome who presented with severe dyspnea. Diagnostic imaging confirmed pulmonary embolism (PE), and treatment comprised unfractionated heparin and apixaban. APLA syndrome was diagnosed based on clinical, serological, and radiological findings. During evaluation, the patient developed cardiogenic shock necessitating catheter-directed thrombolysis, followed by veno-arterial extracorporeal membrane oxygenation (VA-ECMO) due to deteriorating condition and suspected heparin-induced thrombocytopenia (HIT). Surgical embolectomy with bivalirudin use followed, and a hybrid veno-arterial-venous (VAV) ECMO setup was implemented. Postoperatively, the patient improved, transitioning to veno-venous (VV) ECMO and eventually ECMO withdrawal. ECMO is a valuable tool for managing complex cardiorespiratory cases like PE. In the context of HIT and APLA syndrome, prompt anticoagulant transition is vital, and bivalirudin is an effective heparin alternative. Our study highlights the challenges involved in managing patients needing ECMO support with immunothrombotic conditions like HIT and APLA syndrome.

Exploring the level of agreement among different drug-drug interaction checkers: a comparative study on direct oral anticoagulants

BACKGROUND

Direct oral anticoagulants (DOACs) may be involved in drug-drug interactions (DDIs) potentially increasing the risk of adverse drug reactions. This study aimed to evaluate the level of agreement among interaction checkers (ICs) and DOACs' summary of product characteristics (SPCs), in listing DDIs and in attributing DDIs' severity.

RESEARCH DESIGN AND METHODS

The level of agreement among five ICs (i.e. INTERCheck WEB, Micromedex, Lexicomp, Epocrates, and drugs.com) in identifying potential DDIs and in attributing severity categories was evaluated using Gwet's AC1 on all five ICs and by comparing groups of four- and two-pair sets of ICs.

RESULTS

A total of 486 potentially interacting drugs with dabigatran, 556 for apixaban, 444 for edoxaban, and 561 for rivaroxaban were reported. The level of agreement among the ICs in identifying potential DDIs was poor (range: 0.12-0.16). Similarly, it was low in 4 and 2 sets analyses. The level of agreement among the ICs in classifying the severity of potential DDIs was poor (range: 0.32-0.34), also in 4 and 2 sets analyses.

CONCLUSIONS

The heterogeneity among different ICs and SPCs underscores the need to standardize DDI datasets and to conduct real-world studies to generate evidence regarding the frequency and clinical relevance of potential DOAC-related DDIs.

Toward Genetic Testing of Rivaroxaban? Insights from a Systematic Review on the Role of Genetic Polymorphism in Rivaroxaban Therapy

BACKGROUND

Investigations into the rivaroxaban response from the perspective of genetic variation have been relatively recent and wide in scope, whereas there is no consensus on the necessity of genetic testing of rivaroxaban. Thus, this systematic review aims to thoroughly evaluate the relationship between genetic polymorphisms and rivaroxaban outcomes.

METHODS

The PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese databases were searched to 23 October 2022. We included cohort studies reporting the pharmacogenetic correlation of rivaroxaban. Outcomes measured included efficacy (all-cause mortality, thromboembolic events and coagulation-related tests), safety (major bleeding, clinically relevant non-major bleeding [CRNMB] and any hemorrhage), and pharmacokinetic outcomes. A narrative synthesis was performed to summarize findings from individual studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the reporting guideline for Synthesis Without Meta-Analysis.

RESULTS

A total of 12 studies published between 2019 and 2022 involving 1364 patients were included. Ten, one, and six studies focused on the ABCB1, ABCG2, and CYP gene polymorphisms, respectively. Pharmacokinetic outcomes accounted for the majority of the outcomes reported (n = 11), followed by efficacy (n = 5) [including prothrombin time (PT) or international normalized ratio (n = 3), platelet inhibition rate (PIR) or platelet reactivity units (PRUs; n = 1), thromboembolic events (n = 1)], and safety (n = 5) [including major bleeding (n = 2), CRNMB (n = 2), any hemorrhage (n = 1)]. For ABCB1 gene polymorphism, the relationship between PT and ABCB1 rs1045642 was inconsistent across studies, however there was no pharmacogenetic relationship with other efficacy outcomes. Safety associations were found in ABCB1 rs4148738 and major bleeding, ABCB1 rs4148738 and CRNMB, ABCB1 rs1045642 and CRNMB, and ABCB1 rs2032582 and hemorrhage. Pharmacokinetic results were inconsistent among studies. For ABCG2 gene polymorphism, no correlation was observed between ABCG2 rs2231142 and dose-adjusted trough concentration (Cmin/D). For CYP gene polymorphisms, PIR or PRUs have a relationship with CYP2C19 rs12248560, however bleeding or pharmacokinetic effects did not show similar results.

CONCLUSIONS

Currently available data are insufficient to confirm the relationship between clinical or pharmacokinetic outcomes of rivaroxaban and gene polymorphisms. Proactive strategies are advised as a priority in clinical practice rather than detection of SNP genotyping.

CLINICAL TRIALS REGISTRATION

PROSPERO registration number CRD42022347907.