Management of Bleeding With Non-Vitamin K Antagonist Oral Anticoagulants in the Era of Specific Reversal Agents

Efficacy of pro-haemostatic agents in the management of factor Xa inhibitor-associated intracranial haemorrhages

BACKGROUND

An increasing number of patients in Australia are taking direct oral anticoagulants for a variety of indications since their introduction in the treatment landscape. There has always been some concern about the optimal management approach in the setting of major and/or life-threatening bleeding. In particular, patients who present with factor Xa inhibitor-associated intracranial haemorrhages are associated with high morbidity and mortality.

AIM

To determine the efficacy of pro-haemostatic agents in the management of factor Xa inhibitor-related intracranial haemorrhages.

METHODS

A retrospective audit of rivaroxaban and apixaban-associated intracranial haemorrhages was performed between January 2015 and December 2021, inclusive.

RESULTS

The bleeding-related mortality was similar between the patients who received pro-haemostatic agents versus patients who did not receive pro-haemostatic agents (90% vs 93% respectively). The mean volume expansion for those who received pro-haemostatic agents was +1.0mL versus -6.8 mL for patients who did not receive pro-haemostatic agents (P = 0.51, 95% confidence interval: -11.7 to +5.9).

CONCLUSION

Patients who presented with intracranial haemorrhages in the presence of clinically significant direct oral anticoagulant levels had a higher risk of mortality that does not appear to change with the use of prohaemostatic agents. The efficacy of prohaemostatic agents may not be as clinically significant based on real-world experience in contrast to previously reported studies.

Beyond Anticoagulation: A Comprehensive Review of Non-Vitamin K Oral Anticoagulants (NOACs) in Inflammation and Protease-Activated Receptor Signaling

Non-vitamin K oral anticoagulants (NOACs) have revolutionized anticoagulant therapy, offering improved safety and efficacy over traditional agents like warfarin. This review comprehensively examines the dual roles of NOACs-apixaban, rivaroxaban, edoxaban, and dabigatran-not only as anticoagulants, but also as modulators of inflammation via protease-activated receptor (PAR) signaling. We highlight the unique pharmacotherapeutic properties of each NOAC, supported by key clinical trials demonstrating their effectiveness in preventing thromboembolic events. Beyond their established anticoagulant roles, emerging research suggests that NOACs influence inflammation through PAR signaling pathways, implicating factors such as factor Xa (FXa) and thrombin in the modulation of inflammatory responses. This review synthesizes current evidence on the anti-inflammatory potential of NOACs, exploring their impact on inflammatory markers and conditions like atherosclerosis and diabetes. By delineating the mechanisms by which NOACs mediate anti-inflammatory effects, this work aims to expand their therapeutic utility, offering new perspectives for managing inflammatory diseases. Our findings underscore the broader clinical implications of NOACs, advocating for their consideration in therapeutic strategies aimed at addressing inflammation-related pathologies. This comprehensive synthesis not only enhances understanding of NOACs' multifaceted roles, but also paves the way for future research and clinical applications in inflammation and cardiovascular health.

Latest advances in the reversal strategies for direct oral anticoagulants

BACKGROUND

Since the late 2000s, Europe has granted approval for various thrombotic risk-related uses of direct oral anticoagulants (DOACs). Unlike traditional anticoagulants, DOACs do not necessitate routine coagulation monitoring. Nevertheless, clinical practice often encounters bleeding events associated with these medications, making the need for effective reversal strategies evident.

OBJECTIVES

The study aims to take stock of current reversal strategies for DOACs, with a particular emphasis on the latest compounds that have been developed or are currently under development.

METHODS

For obtaining information regarding the ongoing reversal strategies and the compounds under development, we referred to ClinicalTrials website, PubMed, and Google Scholar.

RESULTS

In 2024, two specific antidotes to DOACs have already received approval when reversal of anticoagulation is needed owing to life-threatening or uncontrolled bleeding: idarucizumab that reverses the effects of dabigatran, and andexanet alfa, designed to counteract activated factor X inhibitors such as apixaban and rivaroxaban. Furthermore, ciraparantag, a potential universal reversal agent, is currently in advanced stages of clinical development. Concerns remain regarding the safety of specific reversal agents, especially concerning the risk of thrombosis. Additionally, the cost of these antidotes remains high. Consequently, nonspecific strategies to counteract anticoagulant medications, including activated charcoal, hemodialysis, and concentrates of coagulation factors, still have utility.

CONCLUSION

With the validation of specific and nonspecific antidotes, DOACs could supplant traditional oral anticoagulants. This progress represents a significant advancement in anticoagulation therapy. However, ongoing research is crucial to address remaining safety concerns of the specific reversion agents of DOACs in clinical practice.

Edoxaban treatment in atrial fibrillation in routine clinical care: One-year outcomes of the prospective observational ETNA-AF study in South Korean patients

Background

The real-world outcomes of edoxaban treatment in patients with atrial fibrillation (AF) were analyzed in the ETNA-AF (Edoxaban Treatment in Routine Clinical Practice) study involving data from multiple regional registries. This report addresses effectiveness and safety of edoxaban in the Korean ETNA-AF population.

Methods

One-year data from 1887 Korean ETNA-AF participants were analyzed according to edoxaban dose and patient age and compared with results of other ETNA-AF registries.

Results

Approximately 70% of patients received the recommended doses of edoxaban (60 mg/30 mg); non-recommended 60 mg and 30 mg doses were prescribed to 9.6% and 19.8% of the patients, respectively. The proportions of reference age (<65 years), youngest-old (65-74 years) and middle-old/oldest-old (≥75 years) groups were 21.4%, 40.2%, and 38.4%, respectively. Incidence of major or clinically relevant nonmajor bleeding was similar within dose (0.57%-1.71%) and age subgroups (1.26%-1.63%). Incidence of net clinical outcome, a composite of stroke, systemic embolic event, major bleeding, and all-cause mortality, was also comparable among dose subgroups (1.14%-3.10%) and age subgroups (2.28%-2.78%). The percentage of Korean patients receiving non-recommended 30 mg (19.8%) was over twice that of the European population (8.4%). However, the clinical outcomes were generally similar among different populations included in the ETNA-AF study.

Conclusions

The outcomes in the Korean ETNA-AF population are like those in the global ETNA-AF population, with overall low event rates of stroke, major bleeding and all-cause mortality across age and dose subgroups. Edoxaban can be used effectively and safely in specific populations of Korean AF patients, including the elderly.

Potential clinical benefits of warfarin in end-stage cancers: A retrospective analysis

Background and Aims

Coagulopathy and thromboembolism are common comorbidities in cancer, and anticoagulants, such as warfarin, are needed in specific situations. This study aimed to determine the clinical relevance of prothrombin time (PT) monitoring and the clinical usefulness of warfarin in patients with malignancy.

Methods

We retrospectively investigated patients with PT lower than 10% treated in our hospital between April 2006 and March 2013. Cases of false coagulopathy, including those due to technical errors during blood sampling, were excluded. The cause of coagulopathy was determined or estimated by physicians.

Results

This study included 338 cases comprising 155 females and 183 males with a median age was 68 (0-97) years. Among them, 89 (26.3%) had cancer, and 163 (48.2%) received warfarin at a median dose of 2.23 (0.5-8.0) mg/day. PT prolongation caused by warfarin overdose and malignancy exacerbation were observed in 75 (22.2%) and 64 (18.9%) patients, respectively. The leading reasons for warfarin administration were arterial fibrillation, chronic heart failure, and deep vein thrombosis. Univariate analysis revealed that the overall survival was higher in the warfarin and nononcology groups than in the nonwarfarin and oncology groups (both p < 0.001). In multivariate analysis, survival was significantly decreased in older adults (p = 0.049), those with malignancy (p < 0.001), and those without warfarin therapy (p < 0.001). Early mortality (within 3 days after PT prolongation) was observed in 65 patients and was mostly related to emergent diseases (36.9%, 24/65) and end-stage malignancy (32.3%, 21/65).

Conclusion

Patients with malignancy may experience subclinical PT prolongation upon disease progression. Warfarin treatment mitigates panic PT values in patients with malignancy. Conversely, those not treated with warfarin have poor survival, suggesting that coagulopathy without warfarin treatment can lead to death. Warfarin enhances hemostatic conditions, thereby preventing malignancy-related lethal hemorrhagic or thromboembolic events.

Saner F, Stark K, Mayerle J, M. Lange C. Platelet Aggregation Inhibitors and Anticoagulants in Gastroenterological and Visceral Surgical Procedures

BACKGROUND

The proper management of patients being treated with platelet aggregation inhibitors or anticoagulant drugs is a common clinical problem for both elective and emergency procedures in gastroenterology and visceral surgery. The essential matters that must be kept in mind in this situation are the hemorrhagic risk of the procedure, the indication for anticoagulation, and the pharmacology of anticoagulant drugs and platelet aggregation inhibitors.

METHODS

This review is based on publications retrieved by a selective search in PubMed and on the guidelines of the relevant specialist societies.

RESULTS

Nearly all procedures in gastroenterology and visceral surgery can be performed under monotherapy with acetyl - salicylic acid. Other platelet aggregation inhibitors, such as clopidogrel or prasugrel, or anticoagulant drugs generally do not need to paused before diagnostic endoscopic procedures with a low risk of bleeding (<1.5%), but they must be paused before procedures in gastroenterology and visceral surgery where the risk of bleeding is high (≥ 1.5%). Bridging with heparin is reserved for patients with a very high risk of thromboembolism ( ≥ 5%).

CONCLUSION

Knowledge of the current recommendations on the management of anticoagulants before gastroenterological and visceral surgical procedures gives the clinician a well-founded means of dealing with this complex and common clinical situation.

CM-352 EFFICACY IN A MOUSE MODEL OF ANTICOAGULANT-ASSOCIATED INTRACRANIAL HAEMORRHAGE

BACKGROUND

Intracranial haemorrhage (ICH) is one of the major devastating complications of anticoagulation. Matrix metalloproteinases (MMPs) inhibition has been proposed as a novel pharmacological approach for ICH treatment.

OBJECTIVES

We evaluated the effects of CM-352 (MMPs-fibrinolysis inhibitor) in an experimental ICH model associated with oral anticoagulants as compared with clinically used prothrombin concentrate complex (PCC).

METHODS

ICH was induced by collagenase injection into the striatum of WT (C57BL/6J) anticoagulated mice (warfarin or rivaroxaban) and Mmp10 -/- mice. Hematoma volume and neurological deficits were measured 24h later by diaminobenzidine staining and different behavioural test. Circulating plasminogen activator inhibitor-1 (PAI-1) activity and interleukin-6 (IL-6) were measured in plasma samples and local inflammation was assessed by neutrophil infiltration. Finally, fibrinolytic effects of MMP-10 and rivaroxaban were evaluated by thromboelastometry and thrombin-activatable fibrinolysis inhibitor (TAFI) activation assays.

RESULTS

Only PCC reduced haemorrhage volume and improved functional outcome in warfarin-ICH, but both, PCC and CM-352 treatments, diminished haemorrhage volume (46%, p<0.01 and 64%, p<0.001, respectively) and ameliorated functional outcome in rivaroxaban-ICH. We further demonstrated that CM-352, but not PCC decreased neutrophil infiltration in the haemorrhage area at 24h. The effect of CM-352 could be related to MMP-10 inhibition since Mmp10-/- mice showed lower haemorrhage volume, better neurological score, reduced IL-6 levels and neutrophil infiltration, and increased PAI-1 after experimental ICH. Finally, we found that CM-352 reduced MMP-10 and rivaroxaban-related fibrinolytic effects in thromboelastometry and TAFI activation.

CONCLUSIONS

CM-352 treatment, by diminishing MMPs and rivaroxaban-associated fibrinolytic effects, might be a novel antihaemorrhagic strategy for rivaroxaban-associated ICH.

Direct (New) Oral Anticoagulants (DOACs): Drawbacks, Bleeding and Reversal

BACKGROUND AND OBJECTIVE

Direct (new) Oral Anticoagulants (DOACs) have emerged as a contemporary and promising option in the treatment of thromboses and VTE, while protecting the coagulation cascade against untoward bleeding events. They are used in the management and prophylaxis of Venous Thromboembolism (VTE) and other thrombotic diseases. The most prominent complication of these agents is bleeding. These agents have similar or lower rates of major intracranial hemorrhages, while they had a higher risk of major gastrointestinal bleeding when compared to warfarin. This manuscript is aimed to revise and update the literature findings to outline the side effects of DOACs in various clinical scenarios.

METHODS

A narrative review of currently published studies was performed. Online database searches were performed for clinical trials published before July 2021, on the efficacy and adverse effects attributed to the anticoagulant treatment, especially DOACs. A literature search via electronic databases was carried out, beginning with the usage of the agents in the Western Languages papers. The search terms initially included direct (new) oral anticoagulants, dabigatran, rivaroxaban, apixaban, edoxaban, idarucizumab, andexanet, prothrombin complex concentrates, and fresh frozen plasma. Papers were examined for methodological soundness before being included.

RESULTS

Severe bleeding episodes require aggressive interventions for successful management. Therefore, bleeding should be evaluated in special regard to the location and rate of hemorrhage, and total volume of blood loss. Patient's age, weight and organ dysfunctions (e.g., kidney/liver failure or chronic respiratory diseases) directly affect the clinical course of overdose.

CONCLUSION

Management recommendations for hemorrhage associated with DOAC use vary, depending on the class of the culprit agent (direct thrombin inhibitor vs. FXa inhibitor), the clinical status of the patient (mild/ moderate vs. severe/life-threatening), and capabilities of the institution. Specific reversal agents (i.e., idarucizumab and andexanet alfa) can be used if available, while prothrombin complex concentrates, fresh frozen plasma and/ or tranexamic acid can also be employed as nonspecific replacement agents in the management of DOAC-related bleeding diathesis.

Associations of anemia with death and major bleeding in patients with atrial fibrillation: A report from the Chinese Atrial Fibrillation Registry Study

Background

Anemia is a common comorbidity in patients with atrial fibrillation (AF). Reports on the association of anemia and adverse events in patients with AF, especially from Asia, are limited.

Methods and Results

Based on data from the Chinese Atrial Fibrillation Registry Study (CAFR), a total of 18,106 AF patients enrolled between August 2011 and December 2018 had hemoglobin (Hb) values recorded at baseline. Patients were classified into three groups according to Hb levels: 15,606 patients (86.2%) into the no anemia group (male Hb≥130 g/L; female Hb≥120 g/L), 1800 (9.9%) with mild anemia (male 110≤Hb<129 g/L; female 110≤Hb<119 g/L), and 700 (3.9%) with moderate to severe anemia (Hb≤109 g/L). Multivariable Cox regression models were used to determine if anemia was independently associated with all‐cause death, cardiovascular death, or major bleeding, after adjusting for confounders.

Anemia was present in 13.8% of the population at baseline. During a median follow‐up of 4.01 years, the incidences of all‐cause death (1.8, 4.9, and 8.9 per 100 person‐years), cardiovascular death (1.0, 2.9, and 4.5 per 100 person‐years), and major bleeding (0.5, 0.6, and 0.7 per 100 person‐years) were gradually accentuated in patients with no anemia, mild anemia, and moderate to severe anemia, respectively. Compared with patients with no anemia, those with anemia had higher risks for all‐cause death (mild anemia; adjusted hazard ratio [HR]: 1.22, 95% confidence interval [CI]: 1.08–1.38; moderate to severe anemia; adjusted HR: 1.53, 95% CI: 1.31–1.77); and cardiovascular death (mild anemia; adjusted HR: 1.29, 95% CI: 1.10–1.52; moderate to severe anemia; adjusted HR: 1.27, 95% CI: 1.03–1.57), but not for major bleeding. The association between anemia and all‐cause death was similar among subgroups stratified by sex, kidney function, anticoagulant, or ablation therapy.

Conclusions

Anemia was associated with increased risks of all‐cause death, cardiovascular death, but no major bleeding in AF patients. The effect of anemia correction on the prognosis of patients with AF requires further study.

Efficacy and safety of antithrombotic therapy with non-vitamin K antagonist oral anticoagulants after transcatheter aortic valve replacement: a systematic review and meta-analysis

Objective:

A meta-analysis was performed to compare the efficacy and safety of antithrombotic therapy with non-vitamin K antagonist oral anticoagulants (NOACs) versus standard care in patients after successful transcatheter aortic valve replacement (TAVR).

Methods:

A systematic search of PubMed, Cochrane Central Register of Controlled Trials, and EMBASE databases and ClinicalTrials.gov website (through 21 October 2020) was performed. Risk ratios (RRs) with 95% confidence intervals (CIs) for all outcomes were calculated using random-effects models.

Results:

Twelve studies (two studies were randomized controlled trials) comprising 6943 patients were included (5299 had indications for oral anticoagulation (OAC) and 1644 had none). No significant differences were found between NOACs and the standard care in the incidences of all stroke, a composite endpoint, and major/life-threatening bleeding. NOACs were associated with lower all-cause mortality than vitamin K antagonists (VKAs) in post-TAVR patients with indications for OAC after more than 1 year of follow-up [RR = 0.64; 95% CI, (0.42, 0.96); p = 0.03], whereas NOACs exhibited poor outcomes than antiplatelet therapy (APT) in patients without indications for OAC [RR = 1.66; 95% CI, (1.12, 2.45); p = 0.01]. In the prevention of valve thrombosis, NOACs and VKAs were not significantly different in patients with indications for OAC [RR = 0.66; 95% CI, (0.24, 1.84); p = 0.43], whereas NOACs were better than APT in patients without indications for OAC [RR = 0.19; 95% CI, (0.04, 0.83); p = 0.03].

Conclusions:

In patients with indications for OAC, post-TAVR antithrombotic therapy with NOACs was more favorable due to its lower all-cause mortality after more than 1 year of follow-up. In those without indications for OAC, NOACs presented poorer outcomes due to its higher all-cause mortality.

A strategy of idarucizumab for pericardial tamponade during perioperative period of atrial fibrillation ablation

OBJECTIVE

To investigate theoptimal idarucizumab (dabigatran antagonist) usage strategy for patients with acute pericardial tamponade receiving uninterrupted dabigatran during catheter ablation for atrial fibrillation (AF).

METHODS

Ten patients presenting acute pericardial tamponade while receiving uninterrupted dabigatran during catheter ablation for AF in Beijing Anzhen Hospital from January 2019 to July 2020 were enrolled and retrospectively analyzed. A "wait and see" strategy of idarucizumab was carried out for all patients; in brief, idarucizumab was applied following pericardiocentesis, comprehensive evaluation of bleeding and hemostasis.

RESULTS

There were five males, five paroxysmal AF, and the average age of the patients was 64.0 ± 9.8 years. Among the 10 patients, four were treated with dabigatran 110 mg, six were treated with dabigatran 150 mg, and one was simultaneously given clopidogrel. The average time from pericardial tamponade to the last dose of dabigatran was 8.2 ± 3.4 h. All patients underwent pericardiocentesis successfully, and the average drainage volume was 322.5 ml (220.0 ± 935.0 ml). For reversal anticoagulation, six patients received protamine, and five patients received idarucizumab. Of the five patients who were treated with idarucizumab, four presented exact hemostasis, except for one patient who underwent continuous drainage and finally received surgery repair. The average time to restart anticoagulation was 1.1 ± 0.3 days after the procedure, and no rebleeding, embolism or deaths were observed.

CONCLUSION

The "wait and see" strategy of idarucizumab for acute pericardial tamponade during the perioperative period of catheter ablation for AF may be safe and feasible.

Pre-injury use of antiplatelet and anticoagulations therapy are associated with increased mortality in a cohort of 1038 hip fracture patients

BACKGROUND

Hip fractures are a large burden on the health care systems of developed nations. Patients usually have multiple co-morbidities and the pre-injury use of anticoagulants and anti-platelet medication is common.

MATERIALS AND METHODS

This study used a single hospital hip fracture database to facilitate a retrospective analysis of the impact of anti-coagulation and anti-platelet therapy on mortality and complications after surgical management of hip fractures. There were 92 patients on warfarin, 69 on DOAC, 260 antiplatelet patients and 617 control patients.

RESULTS

Mortality rates at 30 days were 4.8% for the control group, 12.6% for the antiplatelet group, warfarin 7.0%, 9.5% for Direct Oral Anticoagulant (DOAC) group, p = 0.004. Mortality rates at 1 year were 22.4% for the control group, 32.3% for the antiplatelet group, 29.3% for the warfarin group and 29.0% for DOAC group (p=0.007). Amongst complications, significant differences were found in transfusion (DOAC) and wound ooze (warfarin) rates, but the study did not detect significant clinical consequences arising from these differences. A matched analysis for age, sex, and ASA was undertaken to look in more detail at mortality data. Some mortality differences remained between groups with anti-platelet medication associated with increased mortality, but the differences no longer appeared to be significant. Our data suggests that this is a non-causal association, which could be incorporated into predictive mortality risk scores such as the Nottingham hip fracture score.

CONCLUSION

We believe that pre-injury antiplatelet therapy is a strong indicator for high risk patients with higher expected mortality after hip fracture surgery. We saw no evidence to support delayed surgery in patients taking DOACs.

Use of direct-acting oral anticoagulants in solid organ transplantation: A systematic review

The use of direct-acting oral anticoagulants (DOACs) has increased secondary to the mounting evidence for comparable efficacy and potentially superior safety to vitamin K antagonists (VKAs) in the general population. However, insufficient data regarding DOAC use in solid organ transplant (SOT) recipients and numerous pharmacokinetic and pharmacodynamic considerations limit their use in this highly selected patient population. A systematic review of recent clinical evidence on the safety and efficacy of DOACs compared to VKAs in SOT recipients was conducted. Additional considerations including transplant-specific strategies for DOAC reversal and common pharmacokinetic/pharmacodynamic concerns were also reviewed. Although current evidence is limited to single-center retrospective analyses, DOACs, especially apixaban, appear to be a safe and effective alternative to VKAs for SOT recipients with stable graft function and without drug-drug interactions. Reliable data on DOAC reversal at the time of transplant surgery are lacking, and clinicians should consider idarucizumab, andexanet alfa, and other non-specific reversal agents on an individual patient basis. There is no evidence supporting deviations from the Food and Drug Administration labeling recommendations for DOAC dosing in the setting of drug-drug interactions, obesity, and renal function, especially in patients on hemodialysis.

The Pharmacological Approach to Oncologic Patients with Acute Coronary Syndrome

Among acute coronary syndrome (ACS) patients, 15% have concomitant cancer, especially in the first 6 months after their diagnosis, as well as in advanced metastatic stages. Lung, gastric, and pancreatic cancers are the most frequent malignancies associated with ACS. Chemotherapy and radiotherapy exert prothrombotic, vasospastic, and proinflammatory actions. The management of cancer patients with ACS is quite challenging: percutaneous revascularization is often underused, and antiplatelet and anticoagulant pharmacological therapy should be individually tailored to the thrombotic risk and to the bleeding complications. Sometimes oncological patients also show different degrees of thrombocytopenia, which further complicates the pharmacological strategies. The aim of this review is to summarize the current evidence regarding the treatment of ACS in cancer patients and to suggest the optimal management and therapy to reduce the risk of adverse coronary events after ACS in this high-risk population.

Non-vitamin K antagonist oral anticoagulants for stroke prevention in atrial fibrillation: safety issues in the elderly

INTRODUCTION

Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly used for stroke prevention in patients with atrial fibrillation (AF). Since NOACs are predominantly used in the elderly with AF at high risk for stroke and bleeding and with comorbidities requiring polypharmacy, it is important to assess their safety and efficacy in this population.

AREAS COVERED

We review changes in pharmacokinetics and pharmacodynamics observed with senescence and the effect on NOACs and drug and food interactions. We also provide an update on challenges related to NOAC use in situations that increases the risk for bleeding or require temporary discontinuation and address practical issues in the elderly AF patients managed on NOACs. Clinical studies and trials with cardiovascular outcomes reported from January 1990 to August 2020 were identified through the Medline database using PubMed, Cochrane Library, and EMBASE database.

EXPERT OPINION

NOACs are highly effective in preventing stroke in AF patients with non-inferior or superior efficacy to warfarin, with reduced risk of major bleeding. However, in the older-elderly, evidence comes mainly from observational studies or extrapolation from studies in populations with minimal functional limitations or comorbidities. The high upfront cost and out-of-pocket expense for copayment or deductibles also limit the use of this effective therapy in a substantial number of patients. The cost reduction may further improve long-term use for NOACs in stroke prevention in elderly patients with AF.

Reversal of rivaroxaban anticoagulant effect by prothrombin complex concentrates: which dose is sufficient to restore normal thrombin generation?

Rivaroxaban has the most available data to support the use of prothrombin complex concentrates (PCC) as a reversal agent. However, PCC might increase the incidence of thrombotic events by shifting the haemostatic balance towards hypercoagulability. We assessed the in vitro efficacy and safety of three 4-factor PCCs for reversing rivaroxaban anticoagulant effect. Our in vitro finding indicates that 4-factor PCCs at the dose of 25 U.kg^− 1 may be sufficient to reverse rivaroxaban anticoagulant effect.

Direct oral anticoagulants in oral surgery: a prospective cohort

BACKGROUND

Quantitative assessment of bleeding in dental extractions is rarely reported in the literature. The assessment of bleeding might provide additional evidence to predict and minimize postoperative outcomes. The aim of this study was to evaluate the pattern of bleeding in individuals taking direct oral anticoagulants (DOACs) submitted to dental extractions.

METHODS

Intraoperative bleeding was evaluated by using total collected bleeding corrected by absorbance reading (dental bleeding score). To monitoring bleeding episodes from the day of surgery, this cohort was followed up until the seventh postoperative day.

RESULTS

Forty-five procedures were performed in three comparative groups, patients under DOACs, individuals taking vitamin K antagonists (VKAs) and without anticoagulant therapy. No bleeding events were observed in procedures carried out in individuals of the DOAC group. Additional hemostatic measures were required in two procedures in the VKA group and one in the non-anticoagulated group. The dental bleeding scores obtained for the DOAC and VKA groups were similar.

CONCLUSIONS

Our data suggest that the DOAC therapy did not result in increased bleeding outcomes in this sample.

Annexin A4 inhibits sulfatide-induced activation of coagulation factor XII

BACKGROUND

Factor XII (FXII) is a plasma serine protease that initiates the intrinsic pathway of blood coagulation upon contact with anionic substances, such as the sulfated glycolipid sulfatide. Annexins (ANXs) have been implicated in the regulation of the blood coagulation reaction by binding to anionic surfaces composed of phospholipids and sulfated glycoconjugates, but their physiological importance is only partially understood.

OBJECTIVE

To test the hypothesis that ANXs are involved in suppressing the intrinsic pathway initiated by sulfatide, we examined the effect of eight recombinant ANX proteins on the intrinsic coagulation reaction and their sulfatide binding activities.

METHODS

Recombinant ANXs were prepared in Escherichia coli expression systems and their anticoagulant effects on the intrinsic pathway initiated by sulfatide were examined using plasma clotting assay and chromogenic assay. ANXA4 active sites were identified by alanine scanning and fold deletion in the core domain.

RESULTS AND CONCLUSIONS

We found that ANXA3, ANXA4, and ANXA5 strongly inhibited sulfatide-induced plasma coagulation. Wild-type and mutated ANXA4 were used to clarify the molecular mechanism involved in inhibition. ANXA4 inhibited sulfatide-induced auto-activation of FXII to FXIIa and the conversion of its natural substrate FXI to FXIa but showed no effect on the protease activity of FXIIa or FXIa. Alanine scanning showed that substitution of the Ca2+ -binding amino acid residue in the fourth fold of the core domain of ANXA4 reduced anticoagulant activity, and deletion of the entire fourth fold of the core domain resulted in complete loss of anticoagulant activity.

Direct oral anticoagulants and cardiac surgery: A descriptive study of preoperative management and postoperative outcomes

OBJECTIVE

Recommendations for perioperative management of direct oral anticoagulant (DOAC) treatment in cardiac surgery are lacking. To establish a standardized approach for these patients, we compared hemorrhagic complications and clinical outcomes in patients on DOAC medication, patients on vitamin K antagonists (VKA), and patients without preoperative anticoagulation.

METHODS

All 3 groups underwent major cardiac surgery and were retrospectively analyzed: patients on DOAC were advised to take their last DOAC dose 4 days before hospital admission, and DOAC plasma levels were measured the day before surgery. In patients with plasma levels of >30 ng/mL, surgery was postponed until plasma level was below this threshold level. Postoperative chest tube drainage, bleeding complications, use of blood products, and thromboembolic events were collected for all groups.

RESULTS

A total of 5439 patients no anticoagulation, 239 patients on VKA, and 487 patients on DOAC medication were included between April 2014 and July 2017. Adjusted postoperative chest tube drainage did not differ between the DOAC and VKA groups for the strategy applied in this study (380 mL/12 hours vs 360 mL/12 hours). Moreover, secondary endpoint measures, such as rethoracotomy (30 [6.16%] vs 15 [6.28%]), 30-day-mortality 12 [2.46%] vs 7 [2.93%]), blood-product use, and stroke, were not significantly different through implementation of our standardized study management (P > .05).

CONCLUSIONS

Our standardized management for perioperative discontinuation of DOAC therapy may provide a safe approach to minimize hemorrhagic complications in cardiac surgery in patients on DOACs.

Clinical benefits and risks of antithrombotic therapy in patients with atrial fibrillation with comorbidities - A report from the CHART-2 Study

BACKGROUND

The benefits of antithrombotic therapy (ATT) for atrial fibrillation (AF) are occasionally offset by major bleeding complications. However, the clinical benefits and risks of ATT in AF patients, with special references to comorbidities, such as heart failure (HF), coronary artery disease (CAD), and the patterns of AF, remain to be fully elucidated.

METHODS

A total of 3221 consecutive AF patients from our Chronic Heart Failure Analysis and Registry in the Tohoku District-2 (CHART-2) Study (N = 10,219) were divided into 4 groups based on ATT at enrollment; no-ATT, anticoagulant alone, antiplatelet alone, and both of them (AC&AP). Then, efficacy and safety outcomes including thromboembolic events, major bleeding, and mortality were evaluated among the 4 groups.

RESULTS

Anticoagulant monotherapy was associated with reduced risk of ischemic stroke in patients with but not in those without HF, CAD, or non-paroxysmal AF. Although there was no significant difference in major bleeding among the 4 groups, a composite of thromboembolism and major bleeding occurred more frequently in the AC&AP group, even in combination with anticoagulants and single antiplatelet therapy, indicating that the combination therapy is more harmful than anticoagulant monotherapy for AF patients, especially for those with HF or CAD. Lastly, no-ATT group was associated with worse prognosis compared with other 3 groups.

CONCLUSIONS

These results indicate that ATT is beneficial for AF patients particularly for those with HF, CAD, or non-paroxysmal AF and that among ATT, anticoagulant monotherapy may be most profitable for both clinical benefits and risks for AF patients.

Continued vs. interrupted direct oral anticoagulants at the time of device surgery, in patients with moderate to high risk of arterial thrombo-embolic events (BRUISE CONTROL-2)

Aims

Guidelines recommend warfarin continuation rather than heparin bridging for pacemaker and defibrillator surgery, after the BRUISE CONTROL trial demonstrated an 80% reduction in device pocket haematoma with this approach. However, direct oral anticoagulants (DOACs) are now used to treat the majority of patients with atrial fibrillation. We sought to understand the best strategy to manage the DOACs at the time of device surgery and specifically hypothesized that performing device surgery without DOAC interruption would result in a reduced haematoma rate.

Methods and results

We randomly assigned patients with atrial fibrillation and CHA2DS2-VASc score ≥2, to continued vs. interrupted DOAC (dabigatran, rivaroxaban, or apixaban). The primary outcome was blindly evaluated, clinically significant device pocket haematoma: resulting in re-operation, interruption of anticoagulation, or prolonging hospital stay. In the continued arm, the median time between pre- and post-operative DOAC doses was 12 h; in the interrupted arm the median time was 72 h. Clinically significant haematoma occurred in of 7 of 328 (2.1%; 95% CI 0.9-4.3) patients in the continued DOAC arm and 7 of 334 (2.1%; 95% CI 0.9-4.3) patients in the interrupted DOAC arm (P = 0.97). Complications were uncommon, and included one stroke and one symptomatic pericardial effusion in each arm.

Conclusions

These results suggest that, dependent on the clinical scenario, either management strategy (continued DOAC or interrupted DOAC) might be reasonable, at least for patients similar to those enrolled in our trial.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

Perioperative Management of Patients Receiving New Anticoagulants

There is an increased use of oral anticoagulants for the prevention of venous and arterial thrombosis. Vitamin-K antagonists have been used for decades as the main oral anticoagulants but they have the draback a complex therapeutic management, slow onset of action and by a different oral intake caused by dietary vitamin K intake. New non-vitamin K antagonist oral anticoagulants (NOACs) have been developed to overcome the limitations of warfarin. Their management is easier as it requires a fixed daily dose without coagulation monitoring. Although their therapeutic profile is safe, proper attention should be paid in case of unexpected need for the reversal of their coagulation effect and in case a patient needs to have a scheduled surgery. For non-acute cardiac surgery, discontinuation of NOACs should start at least 48 hours prior surgery. Intracranial bleedings associated with NOACs are less dangerous comparing to those warfarin-induced. NOACs need to be stopped ≥24 hours in case of elective surgery for low bleeding-risk procedures and ≥48 hours for high bleeding-risk surgery in patients with normal renal function and 72 hours in case of reduced CrCl < 80. The therapy with NOACs should be resumed from 48 to 72 hours after the procedure depending on the perceived bleeding, type of surgery and thrombotic risks. There are some available NOAC reversal agents acting within 5 to 20 minutes. In case of lack of reversal agent, adequate diuresis, renal replacement therapy and activated charcoal in case of recent ingestion should be considered.

Idarucizumab, but not procoagulant concentrates, fully restores dabigatran-altered platelet and fibrin components of hemostasis

BACKGROUND

Comparative studies on the restoration of hemostasis with different reversal agents after dabigatran therapy have not been performed. We compared the efficacy and prothrombotic potential of the specific antidote idarucizumab with that of previously recommended non-specific procoagulant concentrates.

STUDY DESIGN AND METHODS

We explored the in vitro effects of dabigatran (184 ng/mL) on fibrin and platelet-aggregate formation onto a damaged vessel under flow conditions (600 s^-1 ). The reversal mechanisms and efficacy of idarucizumab (0.3-3 mg/mL) were compared with that of the non-specific procoagulant concentrates aPCC (25-75 U/Kg), PCC (70 U/Kg), or rFVIIa (120 μg/Kg). Generation of thrombin and prothrombin fragment (F1 + 2), and thromboelastometry parameters of clot formation were measured.

RESULTS

Dabigatran caused pronounced reductions in fibrin (87%) and platelet interactions (36%) with damaged vessels (p < 0.01) and significantly impaired thrombin generation and thromboelastometric parameters (delayed dynamics and reduced firmness). Idarucizumab completely normalized rates of fibrin and platelet coverage to baseline values in flow studies; and reversed the alterations in thrombin generation, F1 + 2 and thromboelastometry parameters produced by dabigatran. In comparison, aPCC and PCC only partially compensated for the dabigatran-induced alterations in fibrin deposition, but were unable to fully restore them to baseline values. Reversal with aPCC or PCC improved the majority of alterations in coagulation-related tests, but tended to overcompensate thrombin generation kinetics and significantly increased F1 + 2 levels.

CONCLUSION

Idarucizumab antagonizes alterations of direct and indirect biomarkers of hemostasis caused by dabigatran. In our studies, idarucizumab was clearly more efficacious than strategies with non-specific procoagulant concentrates and devoid of the excessive procoagulant tendency observed with the latter.

NOACs in Anesthesiology

Background

Due to increasing use of new oral anticoagulants (NOACs), clinicians are faced more and more frequently with clinical issues related to these drugs.

Objective

The objective of this publication is to make practical suggestions for the perioperative management of NOACs as well as for their handling in overdoses and bleedings.

Recommendations

In elective surgery and creatinine clearance ≥ 50 ml/min, a NOAC should be discontinued 24-36 h before the intervention, and even earlier in case of reduced kidney function. In emergency interventions that cannot be delayed, the management is dependent on the NOAC plasma levels. With levels ≤ 30 ng/ml, surgery can be performed. With levels >30 ng/ml, reversal agents should be considered. In low bleeding risk surgery, NOACs can be re-started 24 h after the intervention, which is prolonged to 48-72 h after surgery with high bleeding risk. In case of NOAC overdose and minor bleedings, temporary discontinuation and supportive care are usually sufficient to control the situation. In severe or life-threatening bleedings, nonspecific and specific reversal agents should be considered.

Evaluation of combined idarucizumab and prothrombin complex concentrate treatment for bleeding related to dabigatran in a lethal porcine model of double trauma

BACKGROUND

Idarucizumab (IDA) is approved for emergency reversal of dabigatran; prothrombin complex concentrates (PCCs) are recommended in the absence of specific antidote. The combined effects of IDA and PCC in trauma-related bleeding are unknown. The efficacy and safety of combined IDA + PCC were assessed in a lethal porcine model of double trauma under dabigatran anticoagulation.

STUDY DESIGN AND METHODS

Male pigs (n = 28) received oral dabigatran etexilate (30 mg/kg bid) for 3 days; a non-dabigatran control group (n = 7) received placebo. On Day 4, dabigatran-treated animals were randomized 1:1:1:1 to receive placebo + placebo (dabigatran-treated control), IDA + PCC (60 mg/kg + 50 IU/kg), PCC + IDA, or IDA + IDA. Trauma was induced at t = 0 (bilateral femur fractures and blunt liver injury) and t = 60 minutes (second blunt liver injury). Study treatment was administered 15 minutes after each trauma. Animals were monitored for 5 hours or until death.

RESULTS

Total blood loss in IDA + PCC, PCC + IDA, and IDA + IDA was 1673 ± 370, 1981 ± 361, and 1417 ± 135 mL, respectively, with 100% survival at 5 hours. Blood loss in dabigatran-treated controls was 4427 ± 162 mL with 100% mortality. With IDA + IDA, plasma coagulation parameters and thrombin generation were similar to non-dabigatran control group levels after the second dose and remained stable over time. In the IDA + PCC and PCC + IDA groups, thrombin generation and d-dimer levels after the second dose were higher than with IDA + IDA. No thromboembolic complications were found.

CONCLUSION

IDA and PCC are effective in treating trauma-related bleeding with dabigatran anticoagulation. IDA is preferable for emergency reversal of dabigatran, but PCC may be valuable when the anticoagulant is unknown.

Compartment syndrome secondary to an atraumatic gastrocnemius tear in a patient on NOACs: presentation and complications of treatment

Acute compartment syndrome is a limb-threatening condition often associated with high-energy injury. We present the case of a man who sustained compartment syndrome secondary to an atraumatic tear in the gastrocnemius muscle and the complications which arose in his treatment due to his being on rivaroxaban.

Plasma contact factors as therapeutic targets

Direct oral anticoagulants (DOACs) are small molecule inhibitors of the coagulation proteases thrombin and factor Xa that demonstrate comparable efficacy to warfarin for several common indications, while causing less serious bleeding. However, because their targets are required for the normal host-response to bleeding (hemostasis), DOACs are associated with therapy-induced bleeding that limits their use in certain patient populations and clinical situations. The plasma contact factors (factor XII, factor XI, and prekallikrein) initiate blood coagulation in the activated partial thromboplastin time assay. While serving limited roles in hemostasis, pre-clinical and epidemiologic data indicate that these proteins contribute to pathologic coagulation. It is anticipated that drugs targeting the contact factors will reduce risk of thrombosis with minimal impact on hemostasis. Here, we discuss the biochemistry of contact activation, the contributions of contact factors in thrombosis, and novel antithrombotic agents targeting contact factors that are undergoing pre-clinical and early clinical testing.

Anti-Xa Oral Anticoagulant Plasma Concentration Assay in Real Life: Rivaroxaban and Apixaban Quantification in Emergency With LMWH Calibrator

BACKGROUND

Oral anti-Xa inhibitors have demonstrated noninferiority to vitamin K antagonists (VKAs) for the prevention of stroke in patients with atrial fibrillation and recurrent venous thromboembolism. They are associated with a decrease in major bleeding. In contrast with VKA, no coagulation monitoring is required. However, in clinical practice, determination of drug concentration is sometimes necessary.

OBJECTIVE

The objective of this study was to evaluate a low-molecular-weight heparin (LMWH) calibrated anti-Xa assay for the quantification of rivaroxaban and apixaban plasma concentration in emergency.

METHODS

The anti-Xa plasma concentration of rivaroxaban and apixaban were measured in emergency in 210 patients using STA anti-Xa liquid assay. For each plasma concentration <150 ng/mL of rivaroxaban or apixaban, an anti-Xa assay calibrated with LMWH was performed.

RESULTS

We demonstrated a significant correlation between LMWH anti-Xa activity and rivaroxaban ( R² = 0.947) or apixaban ( R² = 0.959) concentration and a significant correlation between rivaroxaban and apixaban plasma concentration ( R² = 0.972). A LMWH anti-Xa activity <0.50 IU/mL could exclude a plasma concentration of rivaroxaban and apixaban >30 ng/mL and indicate the feasibility of invasive procedure. Conclusion and Relevance: In the absence of a specific test, LMWH-calibrated anti-Xa assay could be used to determine the presence and evaluate the plasma concentration of oral anti-Xa inhibitors. However, these initial findings require confirmation using other chromogenic calibrated oral anti-Xa assays.

Antidotes for the direct oral anticoagulants: What news?

The direct oral anticoagulants (DOACs) are recommended as the first-choice anticoagulants for both stroke prevention in patients with non-valvular atrial fibrillation and the treatment and secondary prevention of venous thromboembolism. DOACs cause bleeding, albeit less than warfarin. Most bleeding complications can be controlled by general reversal strategies and supportive care. However, in case of life-threatening bleeding, or when urgent invasive procedures are needed, a more rapid and thorough reversal may be required. Idarucizumab, andexanet alfa and ciraparantag have been developed as reversal agents for the DOACs. To date idarucizumab is the only approved antidote and is specific for dabigatran. Andexanet alfa, a reversal agent for the factor Xa inhibitors, is still under investigation, but its approval by regulatory agencies is expected soon. Ciraparantag, a universal antidote, is in an earlier stage of development. Based on the results of clinical trials to date, these compounds appear to be breakthrough for urgent and emergency reversal. When administered at fixed doses, they ensured a rapid, efficient and safe restoration of haemostasis. From a practical perspective, all hospitals should develop local protocols to ensure safe and efficient clinical implementation of reversal strategies. Post-marketing studies will be essential to assess the evolution of management strategies and to confirm the safety and effectiveness of these agents.

Bleeding in patients receiving non-vitamin K oral anticoagulants: clinical trial evidence

In optimizing anticoagulation therapy, it is essential to balance treatment efficacy with the major adverse effect of anticoagulant treatment, bleeding risk. This narrative review examines the efficacy and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran, rivaroxaban, apixaban, and edoxaban compared with standard anticoagulation or placebo. NOAC therapies provide equivalent to superior protection versus standard therapy, with similar or superior safety, and potential benefits in convenience. We will review the phase III evidence for each of the available NOACs in different antithrombotic indications, including atrial fibrillation (in the absence of significant mitral stenosis or mechanical heart valves); prophylaxis of venous thromboembolism (VTE) in patients undergoing orthopedic surgery; and acute and long-term treatment of VTE. Further, we will illustrate scenarios in which the evidence is stronger for a particular agent in the context of the overall positive safety and efficacy profile of NOACs in general. Limitations of the factor Xa inhibitors include the lack of a specific antidote in case of a bleeding emergency (an approved agent is available for reversing the effect of the direct thrombin inhibitor). We discuss the options for mitigating bleeding and describe the ongoing developments towards specific reversal agents. In conclusion, the available data for efficacy and safety, together with reliable pharmacokinetics obviating the need for regular monitoring, indicate that NOACs may offer substantial benefits for patients with nonvalvular atrial fibrillation or VTE.

Non-Vitamin K Oral Anticoagulants Associated Bleeding and Its Antidotes

Oral anticoagulant-associated intracerebral hemorrhage (OAC-ICH) accounts for nearly 20% of all ICH. The number of patients with an indication for oral anticoagulant therapy (OAT) increases with increasing age. OAT became less complicate with the introduction of non-vitamin K oral anticoagulants (NOAC) OAT because of easier handling, favorable risk-benefit profile, reduced rates of ICH compared to vitamin K antagonists and no need for routine coagulation testing. Consequently, despite a better safety profile of NOAC the number of patients with OAC-ICH will increase. The mortality and complication rates of OAC-ICH are high and therefore they are the most feared complication of OAT. Immediate normalization of coagulation is the main goal and therefore knowledge of pharmacodynamics and coagulation status is essential. Laboratory measurements of anticoagulant activity in NOAC patients is challenging as specific tests are not widely available. More accessible tests such as the prothrombin time and activated partial thromboplastin time have important limitations. In dabigatran-associated ICH 5 g Idarucizumab should be administered. In rivaroxaban and apixaban-associated ICHs administration of andexanet alpha should be considered. Prothrombin complex concentrate may be considered if andexanet alpha is not available or in case of an ICH associated with edoxaban.

Management of Anticoagulation in Patients with Atrial Fibrillation Undergoing PCI: Double or Triple Therapy?

PURPOSE OF REVIEW

This review aims to discuss the use of antithrombotic therapy in patients with atrial fibrillation who undergo coronary stenting with emphasis on the use of double vs triple therapy.

RECENT FINDINGS

When combined with systemic anticoagulation, dual antiplatelet therapy results in an unacceptable increase in bleeding without any improvement in prevention of thrombotic events. Direct oral anticoagulants combined with single antiplatelet therapy have reduced bleeding compared with warfarin plus dual antiplatelet therapy. Triple anticoagulation therapy with warfarin or direct oral anticoagulants leads to an excess of bleeding and is not superior in preventing thrombotic events. Recent randomized, controlled trials have shown a significant reduction in major bleeding events in patients treated with dual antithrombotic therapy compared with triple therapy without any difference in efficacy. These findings call into question whether triple therapy should remain a part of standard practice.

Safety of 4-factor prothrombin complex concentrate (4F-PCC) for emergent reversal of factor Xa inhibitors

Background

Although factor Xa inhibitors have become a popular choice for chronic oral anticoagulation, effective drug reversal remains difficult due to a lack of specific antidote. Currently, 4-factor prothrombin complex concentrate (4F-PCC) is considered the treatment of choice for factor Xa inhibitor-related major bleeding. However, safety of 4F-PCC and its risk of thrombosis when used for this off-label purpose remain unclear. The purpose of this retrospective study is to determine the rate of thromboembolism when 4F-PCC is used for the emergent reversal of factor Xa inhibitors.

Methods

We conducted a single-center retrospective review of medical records between 2013 and 2017. Patients were included if they received 4F-PCC to reverse rivaroxaban, apixaban, or edoxaban for emergent invasive procedures or during episodes of major bleeding defined as bleeding with hemodynamic instability, fall in hemoglobin of 2 g/dL, or bleeding requiring blood transfusion. Thrombotic events including myocardial infarction, pulmonary embolism, deep vein thrombosis, cerebral vascular accident, and arterial thrombosis of the limb or mesentery were recorded if they occurred within 14 days of 4F-PCC administration. Data was analyzed using point and interval estimation to approximate the rate and confidence interval of thromboembolic events.

Results

Forty-three patients were identified in our review. Doses of 4F-PCC were determined by the treating physician and mainly ranged from 25 to 50 IU/kg. Twenty-two patients (51.2%) received both sequential compression devices (SCDs) and subcutaneous heparin for DVT prophylaxis. Twenty-one patients (48.8%) were placed on SCDs only. Three patients received concomitant FFP. Thrombotic events within 14 days of 4F-PCC administration occurred in 1 out of 43 patients (2.1%, 95% CI [0.1–12.3]). This thrombotic event was an upper extremity DVT which occurred 1 day after the patient received 1325 IU (25 IU/kg) of 4F-PCC to reverse rivaroxaban for traumatic intracranial hemorrhage. The patient was taken for emergent decompressive craniotomy after rivaroxaban reversal. In patients who did not undergo surgery or who underwent minor invasive procedures, no thrombotic events were noted.

Conclusion

Based on our preliminary data, the thromboembolic rate of 4F-PCC when given at a dose of 25–50 IU/kg to emergently reverse rivaroxaban and apixaban appears acceptable. Since many patients who require 4F-PCC to emergently reverse factor Xa inhibitors will be at high risk of developing thrombotic events, practitioners should be highly vigilant of these complications. Large, multicenter prospective trials are needed to further determine this risk.

Management of venous thromboembolism with non-vitamin K oral anticoagulants: A review for nurse practitioners and pharmacists

BACKGROUND AND PURPOSE

Venous thromboembolism (VTE), comprising deep-vein thrombosis and pulmonary embolism, is associated with significant morbidity and mortality. Non-vitamin K oral anticoagulants (NOACs), including apixaban, betrixaban, dabigatran, edoxaban, and rivaroxaban, are as effective and safe as vitamin K antagonists (VKAs) for primary prophylaxis, treatment, and/or secondary prevention of VTE and present significant advantages in convenience of use. This review provides guidance to nurse practitioners (NPs) and pharmacists on NOAC usage for the management of VTE and examines how traditional anticoagulation clinics can adapt to cater to patients on NOACs.

METHODS

A review of the scientific literature pertaining to treatment guideline recommendations, large randomized clinical trials, and real-world evidence studies related to VTE management was conducted.

CONCLUSIONS

With current data suggesting that NOACs may present as better alternatives over VKAs for the management of VTE, comprehensively educating NPs and pharmacists can help incorporate these agents in their clinical practice.

IMPLICATIONS FOR PRACTICE

Repurposing anticoagulation clinics, led by well-informed NPs and pharmacists, will allow effective integration and optimal management of patients with VTE taking NOACs as well as those taking VKAs.

Andexanet alfa effectively reverses edoxaban anticoagulation effects and associated bleeding in a rabbit acute hemorrhage model

INTRODUCTION

Increasing use of factor Xa (FXa) inhibitors necessitates effective reversal agents to manage bleeding. Andexanet alfa, a novel modified recombinant human FXa, rapidly reverses the anticoagulation effects of direct and indirect FXa inhibitors.

OBJECTIVE

To evaluate the ability of andexanet to reverse anticoagulation in vitro and reduce bleeding in rabbits administered edoxaban.

MATERIALS AND METHODS

In vitro studies characterized the interaction of andexanet with edoxaban and its ability to reverse edoxaban-mediated anti-FXa activity. In a rabbit model of surgically induced, acute hemorrhage, animals received edoxaban vehicle+andexanet vehicle (control), edoxaban (1 mg/kg)+andexanet vehicle, edoxaban+andexanet (75 mg, 5-minute infusion, 20 minutes after edoxaban), or edoxaban vehicle+andexanet prior to injury.

RESULTS

Andexanet bound edoxaban with high affinity similar to FXa. Andexanet rapidly and dose-dependently reversed the effects of edoxaban on FXa activity and coagulation pharmacodynamic parameters in vitro. In edoxaban-anticoagulated rabbits, andexanet reduced anti-FXa activity by 82% (from 548±87 to 100±41 ng/ml; P<0.0001), mean unbound edoxaban plasma concentration by ~80% (from 100±10 to 21±6 ng/ml; P<0.0001), and blood loss by 80% vs. vehicle (adjusted for control, 2.6 vs. 12.9 g; P = 0.003). The reduction in blood loss correlated with the decrease in anti-FXa activity (r = 0.6993, P<0.0001) and unbound edoxaban (r = 0.5951, P = 0.0035).

CONCLUSION

These data demonstrate that andexanet rapidly reversed the anticoagulant effects of edoxaban, suggesting it could be clinically valuable for the management of acute and surgery-related bleeding. Correlation of blood loss with anti-FXa activity supports the use of anti-FXa activity as a biomarker for assessing anticoagulation reversal in clinical trials.

Comparison of Anticoagulant Therapy for Atrial Fibrillation - Novel Oral Anticoagulants Versus Vitamin K Antagonists

In patients with non-valvular atrial fibrillation (NVAF), oral anticoagulation is important for prevention of stroke and systemic embolism (SE). While Vitamin K antagonists (VKAs) have historically been the standard of care, these medications are limited by numerous food and drug interactions with onerous requirements for frequent monitoring and dose adjustments. Over the past decade, several novel oral anticoagulants (NOACs) have been developed to directly inhibit factor IIa/thrombin (dabigatran) or activated factor X (apixaban, rivaroxaban, edoxaban). These medications have been shown to be at least as effective as warfarin for stroke prevention in NVAF with more favorable safety profiles. However, their advantages are underscored by a lack of specific antidotes and assays quantifying their anticoagulant effects. This paper addresses the use of NOACs compared to VKAs in patients with NVAF, with a special focus on high-risk populations, including the elderly, those with renal disease, diabetes mellitus, coronary artery disease, and previous stroke. The current literature surrounding special clinical scenarios including the treatment of bleeding, perioperative management, and the use of NOACs in cardioversion and catheter ablation will be also discussed.