Direct oral anticoagulants: a review on the current role and scope of reversal agents

Safety and Outcomes with Direct Oral Anticoagulants Versus Vitamin-K Antagonists in Chronic Thromboembolic Pulmonary Hypertension: A Systematic Review, Meta-Analysis, and Meta-Regression

Chronic thromboembolic pulmonary hypertension (CTEPH) is a subtype of pulmonary hypertension characterized by organized thrombi inside the pulmonary vasculature, leading to an increase in pulmonary artery pressure. CTEPH is seen in about 3-4% of patients with acute pulmonary embolism and is associated with poor outcomes. Apart from surgical intervention, lifelong anticoagulation is the mainstay of CTEPH management. Traditionally, CTEPH is managed with vitamin-K antagonists (VKA); however, direct oral anticoagulants (DOACs) are recently gaining popularity. However, the current literature comparing DOACs versus VKAs in CTEPH has inconsistent results. An electronic search of the major bibliographic databases was performed to retrieve studies comparing DOACs versus VKAs in CTEPH patients. For dichotomous outcomes, the odds ratio (ORs) with 95% confidence intervals (CI) were pooled using the DerSimonian and Laird random-effects model to generate forest plots. Statistical significance was considered at P < 0.05. Ten studies were included with 3936 patients (1269 in the DOAC group and 2667 in the VKA group). Treatment with DOAC was associated with no statistically significant difference in the risk of all-cause mortality (OR, 0.78; 95% CI, 0.35-1.71; P < 0.53), venous thromboembolism (OR, 1.19; 95% CI, 0.59-2.40; P = 0.63), major bleeding (OR, 0.68; 95% CI, 0.38-1.22; P = 0.20), and clinically relevant nonmajor bleeding (OR, 1.22; 95% CI, 0.80-1.86; P = 0.37). Our analysis demonstrates that DOACs are noninferior to VKAs in terms of their safety and outcomes profile in CTEPH. Further trials are needed to evaluate more robust evidence and to compare additional outcomes.

Principles for management of hip fracture for older adults taking direct oral anticoagulants: an international consensus statement

Hip fracture is a common serious injury among older adults, yet the management of hip fractures for patients taking direct oral anticoagulants remains inconsistent worldwide. Drawing from a synthesis of available evidence and expert opinion, best practice approaches for managing patients with a hip fracture and who are taking direct oral anticoagulants pre-operatively were considered by a working group of the Fragility Fracture Network Hip Fracture Audit Special Interest Group. The literature and related clinical guidelines were reviewed and a two-round modified Delphi study was conducted with a panel of experts from 16 countries and involved seven clinical specialities. Four consensus statements were achieved: peripheral nerve blocks can reasonably be performed on presentation for patients with hip fracture who are receiving direct oral anticoagulants; hip fracture surgery can reasonably be performed for patients taking direct oral anticoagulants < 36 h from last dose; general anaesthesia could reasonably be administered for patients with hip fracture and who are taking direct oral anticoagulants < 36 h from last dose (assuming eGFR > 60 ml.min-1.1.73 m-2); and it is generally reasonable to consider recommencing direct oral anticoagulants (considering blood loss and haemoglobin) < 48 h after hip fracture surgery. No consensus was achieved regarding timing of spinal anaesthesia. The consensus statements were developed to aid clinicians in their decision-making and to reduce practice variations in the management of patients with hip fracture and who are taking direct oral anticoagulants. Each statement will need to be considered specific to each individual patient's treatment.

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.

Clinical Relevance of Preclinical and Clinical Studies of Four-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Direct Oral Anticoagulants

Direct oral anticoagulants (DOACs) are widely used for the prevention and treatment of venous thromboembolism and stroke. When emergency reversal of DOAC-related anticoagulation is required, specific DOAC reversal agents are recommended, including idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. However, specific reversal agents are not always available, andexanet alfa has not been approved for urgent surgery, and clinicians need to know the patient's anticoagulant medication before administering these treatments. Four-factor prothrombin complex concentrates (4F-PCCs) are recognized as nonspecific, alternative hemostatic agents for treatment of DOAC-related bleeding. Evidence from preclinical and clinical studies shows that they may reduce the anticoagulant effects of DOACs and may help control DOAC-related bleeding. However, randomized controlled trials are lacking, and most data are from retrospective or single-arm prospective studies in bleeding associated with activated factor X inhibitors. There are no clinical data showing the efficacy of 4F-PCC for the treatment of bleeding in dabigatran-treated patients. This review focuses on the current evidence of 4F-PCC use in controlling bleeding associated with DOACs and provides an expert opinion on the relevance of these data for clinical practice. The current treatment landscape, unmet needs, and future directions are also discussed.

Prothrombin Complex Concentrate Utilization in Children's Hospitals

Prothrombin complex concentrates (PCCs) are used to manage bleeding in critically ill children. We performed a repeat cross-sectional study using the Pediatric Health Information System registry to describe PCC utilization in the U.S. children's hospitals over time and determine the relationship between PCC use and specific risk factors for bleeding. We included children < 18 years who received three-factor or four-factor PCC during hospital admission between January 2015 and December 2020 to describe the association between PCC therapy, anticoagulation therapies, and inherited or acquired bleeding diatheses. PCC use steadily increased over the 6-year study period (from 1.3 to 4.6 per 10,000 encounters). Patients exhibited a high degree of critical illness, with 85.0% requiring intensive care unit admission and a mortality rate of 25.8%. PCCs were used in a primarily emergent or urgent fashion (32.6 and 39.3%, respectively) and more frequently in surgical cases (79.0% surgical vs. 21.0% medical). Coding analysis suggested a low rate of chronic anticoagulant use which was supported by review of concomitant anticoagulant medications. PCC use is increasing in critically ill children and does not correlate with specific anticoagulant therapy use or other bleeding risk factors. These findings suggest PCC use is not limited to vitamin K antagonist reversal. Indications, efficacy, and safety of PCC therapy in children require further study.

Rivaroxaban-loaded SLNs with treatment potential of deep vein thrombosis: in-vitro, in-vivo, and toxicity evaluation

OBJECTIVES

Rivaroxaban (RXB), a novel Xa inhibitor having groundbreaking therapeutic potential. However, this drug is associated with few limitations, including its pharmacokinetics related toxicities. Here, we developed RXB-loaded SLNs (RXB-SLNs) to improve its biopharmaceutical profile. Methods: High pressure homogenizer was used to prepare RXB-SLNs, followed by their particle characterization, Transmission electron microscopy (TEM), Dynamic light scattering (DSC), and Powder X-ray diffraction (PXRD) analysis. Beside this, in-vitro, ex-vivo, and in-vivo evaluation, prothrombin time assessment and toxicity was investigated.

RESULTS

RXB-SLNs had their particle size in nano range (99.1 ± 5.50 nm) with excellent morphology and low polydispersity index (0.402 ± 0.02) and suitable zeta potential (-25.9 ± 1.4 mV). The incorporation efficiency was observed around 95.9 ± 3.9%. In-vitro release profiles of the RXB-SLNs exhibited enhanced dissolution (89 ± 9.91%) as compared to pure drug (11 ± 1.43%) after 24 h of the study. PK study demonstrated a seven times enhanced bioavailability of RXB-SLNs when compared with pure drug. Furthermore, RXB-SLNs exhibited an expressive anti-coagulant behavior in human and rat blood plasma. Also, the final formulation exhibited no toxicity after oral administration of the SLNs.

CONCLUSIONS

All together, these studies revealed the capability of the SLNs for carrying the RXB with enhanced therapeutic efficacy and no toxicity, most importantly for the treatment of deep vein thrombosis.

Anticoagulation for Stroke Prevention in Atrial Fibrillation

Cardioembolic stroke from atrial fibrillation causes substantial death and disability in the United States. Treatment with oral anticoagulants provides safe and effective stroke prevention for high-risk patients. This article reviews strategies for the use of anticoagulation and highlights the nurse's role in patient education.

Multidisciplinary consensus document on the management of massive haemorrhage. First update 2023 (document HEMOMAS-II)

This document is an update of the multidisciplinary document HEMOMAS, published in 2016 with the endorsement of the Spanish Scientific Societies of Anaesthesiology (SEDAR), Intensive Care (SEMICYUC) and Thrombosis and Haemostasis (SETH). The aim of this document was to review and update existing recommendations on the management of massive haemorrhage. The methodology of the update was based on several elements of the ADAPTE method by searching and adapting guidelines published in the specific field of massive bleeding since 2014, plus a literature search performed in PubMed and EMBASE from January 2014 to June 2021. Based on the review of 9 guidelines and 207 selected articles, the 47 recommendations in the original article were reviewed, maintaining, deleting, or modifying each of them and the accompanying grades of recommendation and evidence. Following a consensus process, the final wording of the article and the resulting 41 recommendations were approved by all authors.

Multidisciplinary consensus document on the management of massive haemorrhage. First update 2023 (document HEMOMAS-II)

This document is an update of the multidisciplinary document HEMOMAS, published in 2016 with the endorsement of the Spanish Scientific Societies of Anaesthesiology (SEDAR), Intensive Care (SEMICYUC) and Thrombosis and Haemostasis (SETH). The aim of this document was to review and update existing recommendations on the management of massive haemorrhage. The methodology of the update was based on several elements of the ADAPTE method by searching and adapting guidelines published in the specific field of massive bleeding since 2014, plus a literature search performed in PubMed and EMBASE from January 2014 to June 2021. Based on the review of 9 guidelines and 207 selected articles, the 47 recommendations in the original article were reviewed, maintaining, deleting, or modifying each of them and the accompanying grades of recommendation and evidence. Following a consensus process, the final wording of the article and the resulting 41 recommendations were approved by all authors.

Association between genetic polymorphisms in fibrinogen genes and bleeding risk in patients treated with direct oral anticoagulants

Introduction

This study aimed to investigate the association between polymorphisms in fibrinogen genes and bleeding risk in patients receiving direct oral anticoagulants (DOACs).

Method

Patients treated with DOACs from June 2018 to December 2021 were enrolled in the study. Genotyping was done for rs2070011, rs6050, and rs2070022 in fibrinogen alpha chain (FGA); rs1800788, rs4220, and rs4463047 in fibrinogen beta chain (FGB); and rs2066865 and rs1800792 in fibrinogen gamma chain (FGG), along with F2 rs5896 and F10 rs5960. Multivariable logistic regression analysis was performed to investigate the risk factors for bleeding and to develop a risk scoring system.

Results

A total of 468 patients were included in the analysis, 14 of whom experienced major bleeding and 36 experienced clinically relevant non-major bleeding. In the multivariable analysis, overdose, anaemia, F2 rs5896, and FGG rs1800792 were found to be significantly associated with bleeding risk. Specifically, patients with the TT genotype of F2 rs5896 and the CC genotype of FGG rs1800792 had 2.1 times (95% confidence interval [CI] 1.1-3.9) and 2.7 times (95% CI 1.2-5.9) higher bleeding risk than the C allele and T allele carriers, respectively. Based on the risk scoring system, patients with 0, 1, 2, 3, 4, and 5 points were predicted to have 5.2%, 10.8%, 22.4%, 32.3%, 42.3%, and 61.8% of bleeding risk, respectively.

Conclusion

To our knowledge, this is the first study to investigate the effects of polymorphisms in fibrinogen genes on DOAC response. After validation, these results will be useful for personalised DOAC therapy.

Management of Gastrointestinal Bleeding and Resumption of Oral Anticoagulant Therapy in Patients with Atrial Fibrillation: A Multidisciplinary Discussion

Direct oral anticoagulants (DOACs) are recommended for the prevention of thromboembolism in patients with atrial fibrillation (AF), and are now preferred over vitamin K antagonists due to their beneficial efficacy and safety profile. However, all oral anticoagulants carry a risk of gastrointestinal (GI) bleeding. Although the risk is well documented and acute bleeding well codified, there is limited high-quality evidence and no guidelines to guide physicians on the optimal management of anticoagulation after a GI bleeding event. The aim of this review is to provide a multidisciplinary critical discussion of the optimal management of GI bleeding in patients with AF receiving oral anticoagulants to help physicians provide individualized treatment for each patient and optimize outcomes. It is important to perform endoscopy when a patient presents with bleeding manifestations or hemodynamic instability to determine the bleed location and severity of bleeding and then perform initial resuscitation. Administration of all anticoagulants and antiplatelets should be stopped and bleeding allowed to resolve with time; however, anticoagulant reversal should be considered for patients who have life-threatening bleeding or when the bleeding is not controlled by the initial resuscitation. Anticoagulation needs to be timely resumed considering that bleeding risk outweighs thrombotic risk when anticoagulation is resumed early after the bleeding event. To prevent further bleeding, physicians should prescribe anticoagulant therapy with the lowest risk of GI bleeding, avoid medications with GI toxicity, and consider the effect of concomitant medications on potentiating the bleeding risk.

Designing Smaller, Synthetic, Functional Mimetics of Sulfated Glycosaminoglycans as Allosteric Modulators of Coagulation Factors

Natural glycosaminoglycans (GAGs) are arguably the most diverse collection of natural products. Unfortunately, this bounty of structures remains untapped. Decades of research has realized only one GAG-like synthetic, small-molecule drug, fondaparinux. This represents an abysmal output because GAGs present a frontier that few medicinal chemists, and even fewer pharmaceutical companies, dare to undertake. GAGs are heterogeneous, polymeric, polydisperse, highly water soluble, synthetically challenging, too rapidly cleared, and difficult to analyze. Additionally, GAG binding to proteins is not very selective and GAG-binding sites are shallow. This Perspective attempts to transform this negative view into a much more promising one by highlighting recent advances in GAG mimetics. The Perspective focuses on the principles used in the design/discovery of drug-like, synthetic, sulfated small molecules as allosteric modulators of coagulation factors, such as antithrombin, thrombin, and factor XIa. These principles will also aid the design/discovery of sulfated agents against cancer, inflammation, and microbial infection.

Direct Oral Anticoagulants: How Do These Drugs Work, How to Monitor, and What Is Their Role in Orthopaedic Surgery

Postoperative venous thromboembolism is a major adverse event associated with orthopaedic surgery. With the addition of perioperative anticoagulation and antiplatelet therapy, the rates of symptomatic venous thromboembolism have dropped to 1% to 3%, and as such, practicing orthopaedic surgeons must be familiar with these medications, including aspirin, heparin, or warfarin, and the use of direct oral anticoagulants (DOACs). DOACs are increasingly being prescribed due to their predictable pharmacokinetics and increased convenience, as they do not require routine monitoring, and 1% to 2% of the general population is currently anticoagulated. Although the introduction of DOACs has yielded additional treatment options, this has also led to confusion and uncertainty regarding treatment, specialized testing, and when and what reversal agents are appropriate. This article provides a basic overview of DOAC medications, their suggested use in the perioperative setting, effects on laboratory testing, and consideration for when and how to use reversal agents in orthopaedic patients.

Influencia del índice de privación social en resultados durante la pandemia de COVID-19

Objetivo

Determinar la relación del índice de privación de la población con la utilización del sistema sanitario, la mala evolución y la mortalidad durante la pandemia de COVID-19.

Método

Estudio de cohorte retrospectivo de personas con infección por SARS-CoV-2 del 1 de marzo de 2020 al 9 de enero de 2022. Se recopilaron datos sociodemográficos, comorbilidad y tratamientos basales prescritos, otros datos basales y el índice de privación, estimado por sección censal. Se realizaron modelos multivariable de regresión logística multinivel para cada variable de resultado: fallecimiento, mala evolución (definida como fallecimiento o ingreso en la unidad de cuidados intensivos), ingreso y visitas a urgencias.

Resultados

La cohorte se compone de 371.237 personas con infección por SARS-CoV-2. En los modelos multivariable se observó un mayor riesgo de fallecimiento, de mala evolución, de ingreso hospitalario o de visita a urgencias en los quintiles de mayor privación en comparación con el quintil de menor privación. Para el riesgo de ser hospitalizado o de acudir a urgencias, en términos generales hubo diferencias entre todos los quintiles. También se observó que estas diferencias se daban en el primer y el tercer periodos de la pandemia para la mortalidad y la mala evolución, y en todos para el riesgo de ser ingresado o de acudir a urgencias.

Conclusiones

Los colectivos con mayor nivel de privación han tenido mayores tasas de mortalidad y de ingreso en comparación con los colectivos con unas tasas de privación más bajas. Es necesario realizar intervenciones que minimicen estas desigualdades.

Evaluation of Direct Oral Anticoagulant Reversal Agents in Intracranial Hemorrhage: A Systematic Review and Meta-analysis

IMPORTANCE

Direct oral anticoagulant (DOAC)-associated intracranial hemorrhage (ICH) has high morbidity and mortality. The safety and outcome data of DOAC reversal agents in ICH are limited.

OBJECTIVE

To evaluate the safety and outcomes of DOAC reversal agents among patients with ICH.

DATA SOURCES

PubMed, MEDLINE, The Cochrane Library, Embase, EBSCO, Web of Science, and CINAHL databases were searched from inception through April 29, 2022.

STUDY SELECTION

The eligibility criteria were (1) adult patients (age ≥18 years) with ICH receiving treatment with a DOAC, (2) reversal of DOAC, and (3) reported safety and anticoagulation reversal outcomes. All nonhuman studies and case reports, studies evaluating patients with ischemic stroke requiring anticoagulation reversal or different dosing regimens of DOAC reversal agents, and mixed study groups with DOAC and warfarin were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were used for abstracting data and assessing data quality and validity. Two reviewers independently selected the studies and abstracted data. Data were pooled using the random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcome was proportion with anticoagulation reversed. The primary safety end points were all-cause mortality and thromboembolic events after the reversal agent.

RESULTS

A total of 36 studies met criteria for inclusion, with a total of 1832 patients (967 receiving 4-factor prothrombin complex concentrate [4F-PCC]; 525, andexanet alfa [AA]; 340, idarucizumab). The mean age was 76 (range, 68-83) years, and 57% were men. For 4F-PCC, anticoagulation reversal was 77% (95% CI, 72%-82%; I2 = 55%); all-cause mortality, 26% (95% CI, 20%-32%; I2 = 68%), and thromboembolic events, 8% (95% CI, 5%-12%; I2 = 41%). For AA, anticoagulation reversal was 75% (95% CI, 67%-81%; I2 = 48%); all-cause mortality, 24% (95% CI, 16%-34%; I2 = 73%), and thromboembolic events, 14% (95% CI, 10%-19%; I2 = 16%). Idarucizumab for reversal of dabigatran had an anticoagulation reversal rate of 82% (95% CI, 55%-95%; I2 = 41%), all-cause mortality, 11% (95% CI, 8%-15%, I2 = 0%), and thromboembolic events, 5% (95% CI, 3%-8%; I2 = 0%). A direct retrospective comparison of 4F-PCC and AA showed no differences in anticoagulation reversal, proportional mortality, or thromboembolic events.

CONCLUSIONS AND RELEVANCE

In the absence of randomized clinical comparison trials, the overall anticoagulation reversal, mortality, and thromboembolic event rates in this systematic review and meta-analysis appeared similar among available DOAC reversal agents for managing ICH. Cost, institutional formulary status, and availability may restrict reversal agent choice, particularly in small community hospitals.

Antibodies to the phosphatidylserine/prothrombin complex in the diagnosis of antiphospholipid syndrome

Aim. To determine the significance of antibodies to the phosphatidylserine/prothrombin complex (aPS/PT) in patients with systemic lupus erythematosus (SLE) antiphospholipid syndrome (APS). Materials and methods. A total of 190 patients were included in the study: 123 (64.7%) with reliable SLE and 55 (29%) with PAPS. The control group included 100 relatively healthy subjects of comparable age. All patients were tested for classical aPL as well as IgG/IgM-anti-PS/PT by enzyme immunoassay. Results. Based on the average values of IgG/IgM aPS/PT of the control group, the levels of positivity were allocated mean (M) + 3 or 5 standard deviations (SD): M+3SD and M+5SD. IgG aPS/PT levels above 73.6 U/ml (M+5SD) were more accurate diagnostic, for IgM aPS/PT above 18.0 U/ml. IgG-aPS/PT were detected in 84 (44%) of 190 patients. Levels above diagnostic levels were detected in 68 (65%) of 104 patients with APS (55 with PAPS and 59 with SLE+APS). Thrombosis was significantly more common in patients with IgG aPS/PT compared with patients negative for IgG aPS/PT. Arterial but not venous thrombosis was associated with IgG aPS/PT positivity. Conclusion. The frequency of detection of IgG aPS/PT in the examined patients was 44%, IgM aPS/PT 29% and their combination 19% of 190 patients. Half of the patients with probable APS had positive IgG aPS/PT and third IgM aPS/PT. Median IgG aPS/PT were significantly higher in patients with APS compared to patients without APS and the control group. Thrombosis was associated with IgG aPS/PT. Arterial thrombosis was significantly more frequently reported in patients with IgG aPS/PT. The sensitivity of IgG aPS/PT for reliable APS at levels greater than 73.6 units/ml was 59%, specificity 92%, for IgM aPS/PT 35% and 91%, respectively.

Association of direct oral anticoagulant-proton pump inhibitor cotherapy with adverse outcomes: protocol for a population-based cohort study

INTRODUCTION

Proton pump inhibitors (PPIs) are widely used for primary and secondary prevention of upper gastrointestinal bleeding. However, there remains controversy about the overall net clinical benefit of PPIs (omeprazole, rabeprazole, pantoprazole, lansoprazole) when coprescribed with direct oral anticoagulants (DOACs; dabigatran, rivaroxaban, apixaban, edoxaban). Our objective is to explore the risk of clinically relevant events, including bleeding, thromboembolic events and death, in patients prescribed DOACs while taking PPIs versus no PPI.

METHODS AND ANALYSIS

The protocol describes a retrospective cohort study of all Ontario residents aged 66 years or older with atrial fibrillation and at least one pharmacy dispensation for a DOAC identified using linked administrative healthcare databases covering 2009-2020. Ontario drug benefit dispensation records will be used to ascertain PPI exposure during DOAC therapy. The primary outcome is a composite of clinically relevant bleeding, thrombotic events or all-cause death. A minimum of 520 patients in total with at least one of the components of the composite outcome are needed. Poisson regression with a generalised estimating equation model will be used to calculate the adjusted incidence rate difference, incidence rate ratios 95% CI, adjusting for propensity for PPI use using inverse probability of treatment weights.

ETHICS AND DISSEMINATION

This research is exempt from REB review under section 45 of Ontario's Personal Health Information Protection Act. We will report our findings in a peer-reviewed biomedical journal and present them at conferences. The study will provide useful evidence to optimise the coprescription of DOACs and PPIs in practice.

Direct oral anticoagulants and therapeutic adherence: do not let your guard down

BACKGROUND

Direct oral anticoagulants (DOAC) and vitamin K antagonist drugs (VKA) are recommended for stroke prevention in atrial fibrillation and for treatment of venous thromboembolism. Undoubtedly, DOAC have contributed to improve quality of life of these patients, but unfortunately, available 'real world' data show a very high variable compliance to DOAC.

AIMS AND OBJECTIVES

to evaluate predictors that adversely affect therapeutic adherence in patients naive naïve  to DOAC.

METHODS AND POPULATION

this study was conducted on an outpatient population in oral anticoagulant therapy in a period between January 2019 and February 2020. Patients naiveto DOAC and treated for at least 6 months were enrolled. Non-Italian-speaking patients, cognitive or psychiatric disorders, refusal to participate or non-consent to the interview were exclusion criteria. A socio-demographic scale and the 8-item Morisky scale (MMAS-8) questionnaire assessed therapeutic adherence.

RESULTS

One hundred two DOAC-naïve patients were selected from a population of 407 patients on the first visit at our centre. The population was homogeneously represented for gender (males 48%). The mean age was 79.5 years. Atrial fibrillation (65.7%) resulted the main reason for DOAC prescription and a polypharmacy was detected in 47.1% of the patients. Moreover, an optimal adherence to DOAC therapy was assessed in less than 30% of patients.

CONCLUSIONS

Polypharmacy, patient's isolation, such as a low education level were statistically associated with a low therapeutic adherence. Therapeutic adherence remains an unsolved problem for anticoagulated patient. To identify patients at higher risk of poor compliance and therapeutic failure and establish targeted care pathways is a priority.

Direct oral anticoagulants are associated with potentially bleeding lesions in suspected mid-gastrointestinal bleeding

BACKGROUND AND AIM

Direct oral anticoagulants (DOACs) became a widespread alternative in anticoagulant therapy. Nevertheless, concerns are raised about their safety, with increased gastrointestinal bleeding rates being described. There are scarce studies regarding DOACs effect on small-bowel capsule endoscopy (SBCE) findings. We aimed to assess if the detection of lesions with high bleeding potential on SBCE was significantly different in patients treated with DOACs when compared to non-anticoagulated patients and to patients anticoagulated with other agents.

METHODS

Cohort study including consecutive patients who underwent SBCE for suspected mid-gastrointestinal bleeding (MGIB) in 2019 and 2020.

RESULTS

From 148 patients, 38 (25.7%) were anticoagulated, of which 26 (68.4%) with DOACs. P2 lesions were detected in 36.5% (n = 54) of the patients. These lesions were more frequently detected in patients under DOACs treatment when compared to non-anticoagulated patients (69.2% vs. 29.1%; p=.001), and also when compared to patients treated with other anticoagulants (69.2% vs. 33.3%; p=.037). No differences in P2 lesions detection were observed between patients treated with other anticoagulants and non-anticoagulated patients (33.3% vs. 29.1%; p=.747). In multivariate analysis, DOACs usage was significantly associated with higher detection rates of P2 lesions on SBCE, when adjusted for classical risk factors for MGIB (OR: 3.38; 95%CI = 1.23-9.26; p=.018).

CONCLUSIONS

Despite their undeniable cardiovascular benefits and easy applicability, DOACs should still be considered with caution. These drugs were significantly associated with higher risk of potentially bleeding lesions on SBCE when compared to other anticoagulants and represent an independent risk factor for MGIB when adjusted for other variables.

Impact of the Genotype and Phenotype of CYP3A and P-gp on the Apixaban and Rivaroxaban Exposure in a Real-World Setting

Apixaban and rivaroxaban are the two most prescribed direct factor Xa inhibitors. With the increased use of DOACs in real-world settings, safety and efficacy concerns have emerged, particularly regarding their concomitant use with other drugs. Increasing evidence highlights drug−drug interactions with CYP3A/P-gp modulators leading to adverse events. However, current recommendations for dose adjustment do not consider CYP3A/P-gp genotype and phenotype. We aimed to determine their impact on apixaban and rivaroxaban blood exposure. Three-hundred hospitalized patients were included. CYP3A and P-gp phenotypic activities were assessed by the metabolic ratio of midazolam and AUC0−6h of fexofenadine, respectively. Relevant CYP3A and ABCB1 genetic polymorphisms were also tested. Capillary blood samples collected at four time-points after apixaban or rivaroxaban administration allowed the calculation of pharmacokinetic parameters. According to the developed multivariable linear regression models, P-gp activity (p < 0.001) and creatinine clearance (CrCl) (p = 0.01) significantly affected apixaban AUC0−6h. P-gp activity (p < 0.001) also significantly impacted rivaroxaban AUC0−6h. The phenotypic switch (from normal to poor metabolizer) of P-gp led to an increase of apixaban and rivaroxaban AUC0−6h by 16% and 25%, respectively, equivalent to a decrease of 38 mL/min in CrCl according to the apixaban model. CYP3A phenotype and tested SNPs of CYP3A/P-gp had no significant impact. In conclusion, P-gp phenotypic activity, rather than known CYP3A/P-gp polymorphisms, could be relevant for dose adjustment.

Synthesis of the evidence on the impact of pre-operative direct oral anticoagulants on patient health outcomes after hip fracture surgery: rapid systematic review

Purpose

To synthesise the evidence on the impact of pre-operative direct oral anticoagulants (DOACs) on health outcomes for patients who sustain a hip fracture.

Method

A rapid systematic review of three databases (MEDLINE, Embase and Scopus) for English-language articles from January 2000 to August 2021 was conducted. Abstracts and full text were screened by two reviewers and articles were critically appraised. Data synthesis was undertaken to summarise health outcomes examined for DOAC users versus a no anticoagulant group. Key information was extracted for study type, country and time frame, population and sample size, type of DOACs, comparator population(s), key definitions, health outcome(s), and summary study findings.

Results

There were 21 articles identified. Of the 18 studies that examined time to surgery, 12 (57.1%) found DOAC users had a longer time to surgery than individuals not using anticoagulants. Five (83.3%) of six studies identified that DOAC users had a lower proportion of surgery conducted within 48 h Four (40.0%) of ten studies reporting hospital length of stay (LOS) identified a higher LOS for DOAC users. Where reported, DOAC users did not have increased mortality, blood loss, transfusion rates, complication rates of stroke, re-operation or readmissions compared to individuals not using anticoagulants.

Conclusions

The effect of DOAC use on hip fracture patient health was mixed, although patients on DOACs had a longer time to surgery. The review highlights the need for consistent measurement of health outcomes in patients with a hip fracture to determine the most appropriate management of patients with a hip fracture taking DOACs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-022-01937-8.

Endoscopy-Related Bleeding and Thromboembolic Events in Patients on Direct Oral Anticoagulants or Vitamin K Antagonists

BACKGROUND & AIMS

Few prospective studies have assessed the safety of direct oral anticoagulants (DOACs) in elective endoscopy. Our primary aim was to compare the risks of endoscopy-related gastrointestinal bleeding and thromboembolic events in patients on DOACs or vitamin K antagonists (VKAs) in this setting. Secondarily, we examined the impact of the timing of anticoagulant resumption on the risk of delayed bleeding in high-risk therapeutic procedures.

METHODS

We conducted a multicenter, prospective, observational study from January 2018 to March 2020 of 1602 patients on oral anticoagulants (1004 on VKAs and 598 on DOACs) undergoing 1874 elective endoscopic procedures. Our primary outcomes were 90-day thromboembolic events and 30-day endoscopy-related gastrointestinal bleeding. The inverse probability of treatment weighting propensity score method was used for baseline covariate adjustment.

RESULTS

The 2 groups had similar risks of endoscopy-related gastrointestinal bleeding (VKAs vs DOACs, 6.2% vs 6.7%; adjusted odds ratio [OR], 1.05; 95% CI, 0.67-1.65) and thromboembolic events (VKAs vs DOACs, 1.3% vs 1.5%; adjusted OR, 0.90; 95% CI, 0.34-2.38). In high bleeding risk procedures (n = 747), delayed anticoagulant resumption (> 48 hours or 24-48 hours vs < 24 hours) did not reduce the risk of postprocedural bleeding (10.3%, 9%, and 5.8%, respectively; adjusted P = .43). Hot and cold snare polypectomy were the most frequent high-risk interventions (41.8% and 39.8%, respectively).

CONCLUSION

In a prospective study of patients on DOACs or VKAs undergoing elective endoscopy, endoscopy-related bleeding and thromboembolic events showed similar risk. Our study suggests that early anticoagulant resumption is safe in most patients, but more data are needed for advanced high-risk therapeutic procedures.

Effect of a Novel Pocket Compression Device on Hematomas Following Cardiac Electronic Device Implantation in Patients Receiving Direct Oral Anticoagulants

Background

A pocket hematoma is a well-recognized complication that occurs after pacemaker or defibrillator implantation. It is associated with increased pocket infection and hospital stay. Patients suffering from atrial fibrillation and undergoing cardiovascular electronic implantable device (CIED) surgery are widely prescribed and treated with direct oral anticoagulants (DOACs). In this study, the use of a novel compression device was evaluated to examine its ability to decrease the incidence of pocket hematomas following device implantation with uninterrupted DOACs.

Methods

A total of 204 participants who received DOACs and underwent CIED implantation were randomized into an experimental group (novel compression device) and a control group (elastic adhesive tape with a sandbag). The primary outcome was pocket hematoma, and the secondary outcomes were skin erosions and patient comfort score. Grade 3 hematoma was defined as a hematoma that required anticoagulation therapy interruption, re-operation, or prolonged hospital stay.

Results

The baseline characteristics of both groups had no significant differences. The incidence of grades 1 and 2 hematomas was significantly lower in the compression device group than in the conventional pressure dressing group (7.8 vs. 23.5 and 2.0 vs. 5.9%, respectively; P &lt; 0.01). Grade 3 hematoma occurred in 2 of 102 patients in the experimental group and 7 of 102 patients in the control group (2.0 vs. 6.9%; P = 0.03). The incidence rates of skin erosion were significantly lower, and the patient comfort score was much higher in the compression device group than in the control group (P &lt; 0.01). Multivariable logistic regression analysis showed that the use of novel compression device was a significant protective factor for pocket hematoma (OR = 0.42; 95% CI, 0.29–0.69, P = 0.01).

Conclusions

The incidence of pocket hematomas and skin erosions significantly decreases when the proposed compression device is used for patients undergoing device implantation with uninterrupted DOACs. Thus, the length of hospital stay and re-operation rate can be reduced, and patient comfort can be improved.

Clinical Trial Registration

http://www.chictr.org.cn, identifier: ChiCTR2100049430.

Severe Bleeding Risks of Direct Oral Anticoagulants in the Prevention and Treatment of Venous Thromboembolism: A Network Meta-Analysis of Randomised Controlled Trials

OBJECTIVE

The aim of this study was to determine the severe bleeding safety of direct oral anticoagulants (DOACs) for the prevention and treatment of venous thromboembolism (VTE).

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were searched up to 6 January 2021. The incidence of severe bleeding (major, gastrointestinal [GI], intracranial, and fatal) was investigated. Using frequentist network meta-analysis, interventions that were not compared directly could be compared indirectly by the 95% confidence interval (CI), making the search results more intuitive. Based on surface under the cumulative ranking curves (SUCRA), the relative ranking probability of each group was generated.

RESULTS

Thirty-one randomised controlled trials (76 641 patients) were included. For the treatment of VTE, the risk of major bleeding with apixaban was significantly lower than dabigatran (odds ratio [OR] 2.10, 95% CI 1.07 - 4.12) and edoxaban (OR 2.64, 95% CI 1.36 - 5.15). The safety of the drugs was ranked from highest to lowest as follows: major bleeding: apixaban (SUCRA 98.0), rivaroxaban (SUCRA 69.6), dabigatran (SUCRA 50.7), edoxaban (SUCRA 26.5), and vitamin K antagonists (VKAs; SUCRA 5.1); GI bleeding: apixaban (SUCRA 80.7), rivaroxaban (SUCRA 66.8), edoxaban (SUCRA 62.3), VKAs (SUCRA 34.4), and dabigatran (SUCRA 5.8); intracranial bleeding: rivaroxaban (SUCRA 74.4), edoxaban (SUCRA 70.4), dabigatran (SUCRA 58.2), apixaban (SUCRA 44.4), and VKAs (SUCRA 5.6); fatal bleeding: edoxaban (SUCRA 82.7), rivaroxaban (SUCRA 59.2), dabigatran (SUCRA 48.6), apixaban (SUCRA 43.0), and VKAs (SUCRA 16.3). For the prevention of VTE, the risk of major bleeding with apixaban was significantly lower than rivaroxaban (OR 2.14, 95% CI 1.02 - 4.52). Among the four types of bleeding, apixaban had the lowest bleeding risk among DOACs (major bleeding: SUCRA 81.6; GI bleeding: SUCRA 75.4; intracranial bleeding: SUCRA 64.1; fatal bleeding: SUCRA 73.6).

CONCLUSIONS

For the treatment of VTE, in terms of major bleeding and GI bleeding, apixaban had the lowest bleeding risk; in terms of intracranial bleeding, rivaroxaban had the lowest bleeding risk; in terms of fatal bleeding, edoxaban had the lowest bleeding risk. For the prevention of VTE, apixaban had the lowest bleeding risk.

Anti-Phosphatidylserine/Prothrombin Antibodies at Two Points: Correlation With Lupus Anticoagulant and Thrombotic Risk

Antibodies to phospholipids (aPL) and associated proteins are a hallmark in the diagnosis of anti-phospholipid syndrome (APS). Those included in the classification criteria are the lupus anticoagulant (LA) and the IgG and IgM isotypes of anticardiolipin (aCL) and anti-beta-2 glycoprotein I (β2GPI) antibodies. Non-classification criteria markers such as autoantibodies that recognize the phosphatidylserine/prothrombin (aPS/PT) complex have been proposed as biomarkers for APS. Studies of aPS/PT antibodies have shown a strong correlation to clinical manifestations and LA. We aimed to study the value and the persistence of aPS/PT IgG and IgM antibodies in a cohort of consecutive patients with clinical suspicion of APS and their utility as thrombotic risk markers. Our study, with 103 patients, demonstrates that persistently positive results for aPS/PT IgG antibodies were significantly associated with APS classification, thrombosis, triple aPL positivity, LA positive result, and the Global APS Score (GAPSS) > than 9 points (p < 0.01, for each condition). On the other hand, no association was seen with pregnancy morbidity (p = 0.56) and SLE (p = 0.07). Persistence of aPS/PT antibodies, defined according to the current laboratory classification criteria, likely improves the diagnosis and clinical assessment of patients with APS.

Predictors of mortality of COVID-19 in the general population and nursing homes

The factors that predispose an individual to a higher risk of death from COVID-19 are poorly understood. The goal of the study was to identify factors associated with risk of death among patients with COVID-19. This is a retrospective cohort study of people with laboratory-confirmed SARS-CoV-2 infection from February to May 22, 2020. Data retrieved for this study included patient sociodemographic data, baseline comorbidities, baseline treatments, other background data on care provided in hospital or primary care settings, and vital status. Main outcome was deaths until June 29, 2020. In the multivariable model based on nursing home residents, predictors of mortality were being male, older than 80 years, admitted to a hospital for COVID-19, and having cardiovascular disease, kidney disease or dementia while taking anticoagulants or lipid-lowering drugs at baseline was protective. The AUC was 0.754 for the risk score based on this model and 0.717 in the validation subsample. Predictors of death among people from the general population were being male and/or older than 60 years, having been hospitalized in the month before admission for COVID-19, being admitted to a hospital for COVID-19, having cardiovascular disease, dementia, respiratory disease, liver disease, diabetes with organ damage, or cancer while being on anticoagulants was protective. The AUC was 0.941 for this model's risk score and 0.938 in the validation subsample. Our risk scores could help physicians identify high-risk groups and establish preventive measures and better follow-up for patients at high risk of dying.ClinicalTrials.gov Identifier: NCT04463706.

Factor Xa inhibitors: critical considerations for clinical development and testing

The selection of factor (F) X and its activated protease FXa for targeted inhibition to prevent and treat thrombotic conditions is based on an understanding of coagulation biochemistry, sequential steps that occur on tissue factor bearing cells and the interface of coagulation proteins, platelets, mononuclear cells and the nuclear constituents of inflammatory cells. The goal for developing direct oral FXa inhibitors was to achieve rapid, selective, predictable, safe and effective anticoagulation across a broad group of patients expected to derive benefit. The history and development in patient care are exemplars of knowledge, translation and collaboration between the public and private sectors.

Stroke due to Left Atrial Appendage Thrombus after Pulmonary Vein Isolation despite Novel Oral Anticoagulant: A Case Report

In patients with atrial fibrillation, catheter ablation is suggested to reduce the mortality rate and is thus frequently performed. However, peri- and postprocedural thromboembolic complications as well as high recurrence rates of atrial fibrillation limit its advantages and require concomitant anticoagulation. With the advent of novel oral anticoagulants (NOACs), fixed dosing without routine laboratory monitoring became feasible. Nevertheless, several factors are associated with either an overdose or an insufficient drug activity of NOACs. We report on a patient with atrial fibrillation undergoing catheter ablation and cardioversion suffering from ischemic stroke despite being under oral anticoagulation. It turned out that the drug activity of the NOACs used was repeatedly insufficient in spite of regular intake and adequate dosing. In sum, drug activity controls should be taken into consideration in patients with thrombotic events despite oral anticoagulation with NOACs.

Delayed lumbar plexus palsy due to giant psoas hematoma associated with vertebral compression fracture and direct oral anticoagulants: a case report

Background

Osteoporotic vertebral compression fractures (VCFs) are commonly observed in elderly people and can be treated by conservatively with minimal risk of complications in most cases. However, utilization of direct oral anticoagulants (DOACs) increases the risks of secondary hematoma even after insignificant trauma. The use of DOACs increased over the past decade because of their approval and recommendation for both stroke prevention in non-valvular atrial fibrillation and treatment of venous thromboembolism. It is well known that DOACs are safer anticoagulants than warfarin in terms of major and nonmajor bleeding; however, we noted an increase in the number of bleeding events associated with DOACs that required medical intervention. This report describes the first case of delayed lumbar plexus palsy due to DOAC-associated psoas hematoma after VCF to draw attention to potential risk of severe complication associated with this type of common and stable trauma.

Case presentation

An 83-year-old man presented with his left inguinal pain and inability to ambulate after falling from standing position and was prescribed DOACs for chronic atrial fibrillation. Computed tomography angiography revealed a giant psoas hematoma arising from the ruptured segmental artery running around fractured L4 vertebra. Because of motor weakness of his lower limbs and expansion of psoas hematoma revealed by contrast computed tomography on day 8 of his hospital stay, angiography aimed for transcatheter arterial embolization was tried, but could not demonstrate any major active extravasation; therefore spontaneous hemostasis was expected with heparin replacement. On day 23 of his stay, hematoma turned to decrease, but dysarthria and motor weakness due to left side cerebral infarction occurred. His pain improved and bone healing was achieved about 2 months later from his admission, however the paralysis of the left lower limb and aftereffects of cerebral infarction remained after 1 year.

Conclusion

In patients using DOACs with multiple risk factors, close attention must be taken in vertebral injury even if the fracture itself is a stable-type such as VCF, because segmental artery injury may cause massive psoas hematoma followed by lumbar plexus palsy and other complications.

Novel rivaroxaban-loaded poly(lactic-co-glycolic acid)/poloxamer nanoparticles: preparation, physicochemical characterization, in vitro evaluation of time-dependent anticoagulant activity and toxicological profile

Rivaroxaban (RXB), an oral direct factor Xa inhibitor, presents innovative therapeutic profile. However, RXB has shown adverse effects, mainly due to pharmacokinetic limitations, highlighting the importance of developing more effective formulations. Therefore, this work aims at the preparation, physicochemical characterization and in vitro evaluation of time-dependent anticoagulant activity and toxicology profile of RXB-loaded poly(lactic-co-glycolic acid) (PLGA)/poloxamer nanoparticles (RXBNps). RXBNp were produced by nanoprecipitation method and physicochemical characteristics were evaluated. In vitro analysis of time-dependent anticoagulant activity was performed by prothrombin time test and toxicological profile was assessed by hemolysis and MTT reduction assays. The developed RXBNp present spherical morphology with average diameter of 205.5 ± 16.95 nm (PdI 0.096 ± 0.04), negative zeta potential (-26.28 ± 0.77 mV), entrapment efficiency of 91.35 ± 2.40%, yield of 41.81 ± 1.68% and 3.72 ± 0.07% of drug loading. Drug release was characterized by an initial fast release followed by a sustained release with 28.34 ± 2.82% of RXB available in 72 h. RXBNp showed an expressive time-dependent anticoagulant activity in human and rat blood plasma and non-toxic profile. Based on the results presented, it is possible to consider that RXBNp may be able to assist in the development of promising new therapies for treatment of thrombotic disorders.

The in vitro addition of idarucizumab to plasma samples from patients increases thrombin generation

Dabigatran interferes with many coagulation tests. To overcome this obstacle the use of idarucizumab as an in vitro antidote to dabigatran has been proposed. The aim of this study was to test the effect of idarucizumab as an in vitro antidote to dabigatran in ex vivo plasma samples from routine clinical patients examined by a thrombin generation assay (TGA). From 44 patients with atrial fibrillation five blood samples were collected. Thrombin generation was measured in all samples before and after the addition of idarucizumab. When idarucizumab was added to baseline plasma (no dabigatran), it caused a significantly shorter Lag Time and Time to Peak Thrombin, and a higher Peak Thrombin and Endogenous Thrombin Potential (ETP) of TGA. Similar results were obtained when idarucizumab was added to dabigatran-containing plasma, with TGA parameters comparable to baseline + idarucizumab plasma, but not to baseline plasma. In summary, our study showed that in vitro addition of idarucizumab to plasma samples from patients increases thrombin generation. The use of idarucizumab to neutralize dabigatran in patient plasma samples as well as the clinical relevance of in vitro increased thrombin generation induced by idarucizumab needs further investigation.

Rivaroxaban-associated intracranial hemorrhage in Saudi atrial fibrillation patients

Atrial fibrillation is the most common cardiac arrhythmia. Anticoagulation therapy effectively reduces systemic embolization in patients with non-valvular atrial fibrillation, but intracranial hemorrhage (ICH) is a major possible complication. This study assessed the real-time rate of rivaroxaban-associated ICH in Saudi patients.We retrospectively reviewed patients with ICH during rivaroxaban therapy, assessing clinical features and outcomes.Four cases out of 690 patients were identified in total, indicating an incidence of ICH during rivaroxaban therapy of 0.58%. Hematoma expansion developed in 1 case. Three out of four patients were discharged after ICH, and 1 patient died.The incidence of rivaroxaban-related ICH was similar to that previously reported, and the risk of hematoma expansion was low. Further studies are required to validate our results.

Prediction and treatment of bleeding in patients under anticoagulant treatment

Major bleeding is a common complication of anticoagulant treatment. Risk assessment tools are relevant in the management of patients with atrial fibrillation and venous thromboembolism. The combination of clinical, biological and genetic markers is incorporated to build predictive scores to help in the decision process about intensity and duration of treatment. The optimal management of bleeding involves the application of predictive scores in combination with anticoagulant reversal strategies.

Direct oral anticoagulants in patients with severe inherited thrombophilia: a single-center cohort study

We investigated the safety and efficacy of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) associated with severe inherited thrombophilia. In this single-center cohort study, we enrolled 56 consecutive VTE patients with severe inherited thrombophilia, defined as the presence of antithrombin (n = 18), protein C (n = 12) and protein S (n = 12) deficiencies, homozygous Factor V Leiden (n = 3) and prothrombin G20210AA (n = 4) mutations, or combined defects (n = 7). During a median follow-up of 44.5 (IQR 30-52.5) months, rivaroxaban was used in 30 (53.6%), apixabanin 14 (25%), and dabigatran in 12 (21.4%) subjects. Recurrent nonfatal VTE was observed in 5 (8.9%) patients (2.4 per 100 patient-years), treated with rivaroxaban (n = 4) and apixaban (n = 1). Major bleeding and clinically relevant non-major bleeding (CRNMB) occurred in 2 (3.5%) and 4 (7%) subjects, respectively (0.96 per 100 patient-years and 1.92 per 100 patient-years, respectively), including 4 patients on rivaroxaban. The event-free survival analysis showed that the use of rivaroxaban was associated with increased risk of recurrent VTE or bleeding, compared with apixaban or dabigatran (HR 2.76, 95% CI 1.26-3.92, p = 0.039). In conclusion, the results of our cohort study indicate that full-dose dabigatran or apixaban are effective and safe in patients with severe inherited thrombophilia.

Binding of direct oral anticoagulants to the FA1 site of human serum albumin

The anticoagulant therapy is widely used to prevent and treat thromboembolic events. Until the last decade, vitamin K antagonists were the only available oral anticoagulants; recently, direct oral anticoagulants (DOACs) have been developed. Since 55% to 95% of DOACs are bound to plasma proteins, the in silico docking and ligand-binding properties of drugs apixaban, betrixaban, dabigatran, edoxaban, and rivaroxaban and of the prodrug dabigatran etexilate to human serum albumin (HSA), the most abundant plasma protein, have been investigated. DOACs bind to the fatty acid (FA) site 1 (FA1) of ligand-free HSA, whereas they bind to the FA8 and FA9 sites of heme-Fe(III)- and myristic acid-bound HSA. DOACs binding to the FA1 site of ligand-free HSA has been validated by competitive inhibition of heme-Fe(III) recognition. Values of the dissociation equilibrium constant for DOACs binding to the FA1 site (ie, ^calc K_DOAC ) derived from in silico docking simulations (ranging between 1.2 × 10^-8 M and 1.4 × 10^-6 M) agree with those determined experimentally from competitive inhibition of heme-Fe(III) binding (ie, ^exp K_DOAC ; ranging between 2.5 × 10^-7 M and 2.2 × 10^-6 M). In addition, this study highlights the inequivalence of rivaroxaban binding to mammalian serum albumin. Given the HSA concentration in vivo (~7.5 × 10^-4 M), values of K_DOAC here determined indicate that the formation of the HSA:DOACs complexes in the absence and presence of FAs and heme-Fe(III) may occur in vivo. Therefore, HSA appears to be an important determinant for DOACs transport.

Management of Anticoagulation and Antiplatelet Therapy in Glaucoma Surgery

The use of antithrombotic therapy is rising as the population of older adults grows and novel agents with wider indications emerge. Likewise, surgical treatment of glaucoma may become increasingly common as the prevalence of glaucoma increases and innovative treatment options are developed. These trends highlight the need to understand how best to manage antithrombotic therapy in the context of glaucoma surgery. This review article describes current literature on antithrombotic therapy and perioperative thromboembolic risk evaluation based on individual factors. In addition, guidance is offered on the management of antithrombotic therapy in the setting of each type of glaucoma surgery, with an emphasis on a multidisciplinary approach involving the patients' treating physicians.

Anti-factor IIa (FIIa) heparin assay for patients on direct factor Xa (FXa) inhibitors

BACKGROUND

Direct factor Xa (FXa) inhibitors are increasingly prescribed for outpatients, and those transitioning to unfractionated heparin (UFH) for hospital admission are monitored via an anti-FXa assay. Because of assay interference, UFH results would often be critically elevated, confounding dosing.

OBJECTIVES

An anti-factor IIa (FIIa) UFH assay was evaluated for clinical use.

METHODS

The BIOPHEN ANTI-IIa (Aniara Diagnostica) assay and anti-FXa INNOVANCE Heparin assay (Siemens Healthcare Diagnostics Products GmbH) were compared on the Siemens BCS XP system. Samples included UFH controls and calibrators and specimens from patients transitioning from apixaban or rivaroxaban to UFH. Method comparison, linearity, recovery, precision, and interference by direct FXa inhibitors were evaluated. The effect of the BIOPHEN ANTI-IIa assay on the rate of critically high UFH results was retrospectively reviewed 4 months after implementation.

RESULTS

Accuracy studies using 0.24 and 0.50 IU/mL UFH yielded means and standard deviations of 0.26 ± 0.01 and 0.58 ± 0.01 IU/mL, respectively. Within-run and between-run coefficients of variation were 4.6% and 15.5% for the low control, and 1.8% and 10.6% for the high control. The method comparison slope was 0.9965 (r2  = 0.9468). The linear range was 0.1 to 1.3 IU/mL. The assay measured UFH in the presence of 192 ng/mL apixaban or 158 ng/mL rivaroxaban. Introduction of the assay for clinical use reduced the monthly percentage of critically high results from 9.4% to 3.8% for admitted heparinized patients who recently discontinued apixaban or rivaroxaban.

CONCLUSIONS

The BIOPHEN ANTI-IIa assay is suitable for patients transitioning off apixaban or rivaroxaban.

A Review on the Use of Reversal Agents of Direct Oral Anticogulant Drugs in Case of Gastrointestinal Bleeding

BACKGROUND

Major bleeding is a life-threatening condition and a medical emergency with high mortality risk. It is often the complication of anticoagulant's intake. Anticoagulants are commonly used for the prevention and treatment of thrombotic events. The standard therapy with vitamin K antagonist (warfarin) has been frequently replaced by direct oral anticoagulants (DOACs). The latter agents (rivaroxaban, apixaban, edoxaban, dabigatran, and betrixaban) showed better efficacy and safety compared to standard warfarin treatment and they are recommended for the reduction of ischemic stroke. Literature data reported a high risk of gastrointestinal bleeding with DOACs, in particular with dabigatran and rivaroxaban. In case of life-threatening gastrointestinal bleeding, these patients could benefit from the use of reversal agents.

METHODS

We performed an electronic search on PUBMED of the literature concerning reversal agents for DOACs and gastrointestinal bleeding in the Emergency Department from 2004 to 2020.

AIM

This review summarizes the current evidence about three reversal agents idarucizumab, andexanet alfa and ciraparantag, and the use of the first two in the emergency setting in patients with active major bleeding or who need urgent surgery which physicians indicate for a better management approach in order to increase patient's safety.

CONCLUSION

Although these agents have been marketed for five years (idarucizumab) and two years (andexanet alfa) respectively, and despite guidelines considering antidotes as first-line agents in treating life-threatening hemorrhage when available, these antidotes seem to gain access very slowly in the clinical practice. Cost, logistical aspects and need for plasma level determination of DOAC for an accurate therapeutic use probably have an impact on this phenomenon.. An expert multidisciplinary bleeding team should be established so as to implement international guidelines based on local resources and organization.

Updates in periprocedural management of direct oral anticoagulants

PURPOSE OF REVIEW

As the prevalence of patients on antithrombotics is increasing, anesthesiologists must have a firm understanding of these medications and considerations for their periprocedural management. This review details up-to-date periprocedural management of direct oral anticoagulants (DOACs).

RECENT FINDINGS

DOACs have favorable pharmacokinetics including quick onset of action and short half-lives. Periprocedural management of DOACs relies heavily on drug half-life as well as procedural risk of bleeding. Other than a few exceptions, the American College of Cardiologists generally recommends complete clearance of oral anticoagulants prior to high-risk bleeding procedures and partial clearance prior to low-risk bleeding procedures. Procedures with little to no clinical risk of bleeding can be performed without any drug interruption or during trough levels. Exceptions to periprocedural DOAC management pertain to electrophysiology procedures.

SUMMARY

With the exception of no clinically relevant bleeding risk or certain electrophysiology procedures, DOACs should be discontinued periprocedurally in accordance with bleeding risks and drug's half-life. Bridging is generally not recommended for DOACs.

Percutaneous left atrial appendage closure for cerebrovascular accident prevention: rationale, indications, technical aspects, clinical results and future perspective

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The most feared complication of AF is thromboembolism. Oral anticoagulation (OAC) is the standard treatment to reduce thromboembolism occurrence in patients with AF. The rate of relevant bleeding, medical interactions and incompliance under OAC remains consistent. In this context, patients with AF at high risk for thromboembolism and with a contraindication to OAC may be considered as candidates for percutaneous left atrial appendage closure. In this review, we discuss the rationale, indications, technical aspects and clinical results of left atrial appendage closure by means of the WATCHMAN^® (Boston Scientific, MA, USA) device.