Costs and Healthcare Resource Utilization Associated with Idarucizumab or Andexanet Alfa Oral Anticoagulant Reversal in Patients Hospitalized with Life-Threatening Bleeds.

Purpose: To assess costs and healthcare resource utilization (HCRU) associated with the use of idarucizumab for the reversal of dabigatran and andexanet alfa for the reversal of direct oral Factor Xa inhibitors. Methods: This retrospective study utilizing Premier Healthcare Database (PHD) included patients aged ≥18 years on direct oral anticoagulants (DOACs) who experienced life-threatening bleeds, discharged from the hospital during 5/1/2018-6/30/2019, and received idarucizumab or andexanet alfa. Inverse of treatment probability weighting (IPTW) method was used to balance patient and clinical characteristics between treatment cohorts. Results: Idarucizumab patients were older than andexanet alfa patients (median age 81 vs 77 years; p < 0.001), and less likely to experience intracranial hemorrhage (ICH) (37.1%vs 73.8%; p = 0.001). After IPTW adjustment, idarucizumab patients incurred lower mean total hospital costs ($30,413 ± $33,028 vs $44,477 ± $30,036; p < 0.001),and mean intensive care unit (ICU) cost ($25,114 ± $30,433 vs $43,484 ± $29,335; p < 0.001). Conclusions: Anticoagulant reversal therapy with idarucizumab was associated with significantly lower adjusted mean total hospital and ICU costs compared with andexanet alfa. However, a higher prevalence of ICH bleeds was noted in the andexanet alfa group. Trial Registration: Not applicable.

Cost-effectiveness of andexanet alfa versus four-factor prothrombin complex concentrate for the treatment of oral factor Xa inhibitor-related intracranial hemorrhage in the US.

AIM: To conduct a cost-effectiveness analysis (CEA) on the use of andexanet alfa for the treatment of factor Xa inhibitor-related intracranial hemorrhage (ICH) from the US third-party payer and societal perspectives. METHODS: CEA compared andexanet alfa to prothrombin complex concentrate for the treatment of patients receiving factor Xa inhibitors admitted to hospital inpatient care with an ICH. The model comprised two linked phases. Phase 1 utilized a decision tree to model the acute treatment phase (admission of a patient with ICH into intensive care for the first 30 days). Phase 2 modeled long-term costs and outcomes using three linked Markov models comprising the six health states defined by the modified Rankin score. RESULTS: The analysis showed that the strategy of using andexanet alfa for the treatment of factor Xa inhibitor-related ICH is cost-effective, with incremental cost-effectiveness per quality-adjusted life-year gained of $35,872 from a third-party payer perspective and $40,997 from a societal perspective over 20 years. LIMITATIONS: (1) Absence of head-to-head trials comparing therapies included in the economic model, (2) lack of comparative long-term data on treatment efficacy, and (3) bias resulting from the study designs of published literature. CONCLUSION: Given these results, the use of andexanet alfa for the reversal of anticoagulation in patients with factor Xa inhibitor-related ICH may improve quality of life and is likely to be cost-effective in a US context.

Impact of a pharmacist driven anticoagulation reversal program at a large academic medical center.

In major/life-threatening bleeding, administration of timely and appropriate reversal agents is imperative to reduce morbidity and mortality. Due to complexities associated with the use of reversal agents, a clinical pharmacist-driven anticoagulation reversal program (ARP) was developed. The goal of this program was to ensure appropriateness of reversal agents based on the clinical scenario, optimize selection and avoid unintended consequences. This study describes the impact of a pharmacist-driven anticoagulation program on patient outcomes and cost. A single center retrospective chart review of adult patients whom the ARP was consulted from October 2018 to January 2020 was performed. Patients were included in the efficacy analysis if they were > 18 years of age and presented with acute bleeding. Patients were excluded from the efficacy analysis if the recommended reversal agent was not administered, if a repeat head CT was not available for patients who presented with intracranial hemorrhage (ICH), or if the patient was not bleeding. All patients were included in the economic evaluation. The primary outcome was the percentage of patients who achieved effective hemostasis within 24 h of anticoagulation reversal. Secondary outcomes include incidence of thromboembolic events, in-hospital mortality, and cost avoidance. One hundred twenty-one patients were evaluated by the ARP with 92 patients included in the efficacy analysis. The primary sites of bleeding were ICH in 46% and gastrointestinal (GI) in 29%. Hemostasis was achieved in 84% of patients. Thrombotic events occurred in 7.4% of patients and in-hospital mortality was 26.4%. Total cost avoidance was $1,005,871.78. To our knowledge, this is the first study to evaluate the impact of a pharmacist-driven ARP on clinical and economic outcomes. Implementation of a pharmacist-driven ARP was associated with favorable outcomes and cost savings.

Economic Evaluation of Andexanet Versus Prothrombin Complex Concentrate for Reversal of Factor Xa-Associated Intracranial Hemorrhage.

[Figure: see text].

Elevated anti-human factor Xa activity in rabbit and rodent plasma: Implications for preclinical assessment of human factor X in animal models of hemostasis.

A wide variety of animal models on thrombosis and hemostasis are used in thrombosis and hemostasis research for the preclinical assessment of hemostatic agents. While the vertebrate coagulome is highly conserved, human and animal plasmas differ considerably when evaluated in coagulation assays such as prothrombin time (PT), activated partial thromboplastin time (APTT), and calibrated automated thrombography (CAT). Here, we have aimed to provide a reference framework for the evaluation of coagulation assays and inhibition of activated human FXa (hFXa) in various animal plasmas. To do so, a side-by-side evaluation of the extrinsic and intrinsic pathway of coagulation was performed by means of PT, APTT, and CAT measurements on (diluted) pooled plasmas from goats, pigs, rabbits, rats, mice, and humans. Plasma anti-FXa activity was assessed by determining the rate of recombinant hFXa inhibition through chromogenic activity analyses and immunoblotting. In general, rabbit, rat, and mouse plasmas exhibited robust clotting upon stimulation of both the extrinsic and intrinsic pathway, produced more thrombin during CAT upon plasma dilution, and displayed relatively high hFXa inhibitory activities. By comparison, goat, porcine, and human plasma displayed a similar profile in PT and APTT assays, produced less thrombin during CAT upon plasma dilution, and displayed comparable hFXa inhibitory activities. In conclusion, the observed differences in clotting parameters and anti-hFXa activity point to a higher anticoagulant threshold in plasma from rabbits, rats, and particularly in mice relative to human, goat, and porcine plasma. Finally, rat plasma was found to be more relevant to the preclinical assessment of human FX(a) in comparison to murine plasma.

Emergent reversal of oral factor Xa inhibitors with four-factor prothrombin complex concentrate.

BACKGROUND: Controversy exists regarding first-line use of the recently approved reversal agent andexanet alfa due to limitations of the ANEXXA-4 study, thrombotic risks, and high medication acquisition cost. The purpose of this study was to evaluate the safety and effectiveness of 4F-PCC for the reversal of emergent oral fXa inhibitor-related bleeding. Furthermore, we aimed to evaluate a subgroup using strict ANNEXA-4 patient selection criteria. METHODS: This was a retrospective study conducted utilizing chart review of adult patients that received 4F-PCC for oral fXa inhibitor-related bleeding. The primary endpoint was the rate of clinical success defined as achieving excellent or good hemostatic effectiveness following the administration of 4F-PCC. Secondary endpoints included in-hospital mortality and arterial/venous thromboembolism, and cost compared with andexanet alfa. RESULTS: A total of 119 patients were included, with 83 patients in the ANNEXA-4 criteria subgroup. Eighty-five of the 119 patients (71%) required reversal due to intracranial bleeding. Prior to reversal, 70 patients (59%) were taking apixaban and 49 patients (41%) were taking rivaroxaban. Clinical success was achieved in 106 of 119 patients (89%) and 74 of 83 patients (90%) in the strict criteria subgroup. Three of 119 patients (2.5%) had a thrombotic event during hospital stay and the overall mortality rate was 13%. The average cost increase of andexanet alfa compared to 4F-PCC would have been $29,500 per patient. CONCLUSIONS: Administration of 4F-PCC for the reversal of oral fXa inhibitors was effective with relatively low thrombotic risk. Further direct prospective comparison of 4F-PCC to andexanet alfa is warranted.

Clinical implications of assessment of apixaban levels in elderly atrial fibrillation patients: J-ELD AF registry sub-cohort analysis.

PURPOSE: To investigate the distribution of plasma apixaban levels and their relationships with clinical outcomes in elderly patients with atrial fibrillation (AF). METHOD: The J-ELD AF Registry is a multicenter prospective observational study of Japanese non-valvular AF patients aged ≥75 years taking an on-label dose of apixaban (3015 patients from 110 institutions). Among them, plasma apixaban levels at trough were estimated by anti-Xa assay (Api-AXA) in 943 patients. Patients with standard (5 mg bid; n = 431) and reduced (2.5 mg bid; n = 512) dose were further divided into two groups with low and high Api-AXA levels (boundary: median value). RESULTS: The incidence rates (per 100 person-years) of events in the low- and high-Api-AXA groups were as follows: 1.48 and 1.99 (log-rank test, P = 0.695) for stroke or systemic embolism, 0.98 and 1.49 (P = 0.652) for bleeding requiring hospitalization, and 0.49 and 0.99 (P = 0.565) for total deaths in patients with standard dose, versus 0.84 and 1.68 (P = 0.414), 0.42 and 4.64 (P = 0.004), and 2.52 and 6.65 (P = 0.035) in patients with a reduced dose, respectively. In multivariate Cox regression analysis among patients with a reduced dose, a high Api-AXA level was independently associated with bleeding requiring hospitalization (HR 12.12, 95% CI: 1.56-94.22) and nonsignificantly with total deaths. CONCLUSIONS: A high trough apixaban level in patients indicated for standard dose was not associated with adverse events, while a high apixaban level in patients indicated for a reduced dose was associated with bleeding requiring hospitalization.

Request for an Andexxa Value Analysis.

This perspective is a formal request to the American College of Cardiology and American Heart Association (ACC/AHA) to perform a value analysis on andexanet (Andexxa) similar to what was completed for the PCSK9 inhibitors in the 2018 ACC/AHA Blood Cholesterol guidelines. Based on the safety and efficacy concerns of andexanet alfa, a value statement in and or as an addendum to society guidelines is vital considering the high cost of therapy. In this era of ever-increasing health care costs, every clinician, health system, national society, insurer, and pharmaceutical company should work to be good stewards of our society's resources.

Cost comparison of andexanet versus prothrombin complex concentrates for direct factor Xa inhibitor reversal after hemorrhage.

Andexanet-alpha is a specific reversal agent for direct factor Xa inhibitors (dFXaI). We aimed to project utilization rates and cost of andexanet for reversal of dFXaI-related major hemorrhage compared to 4-factor prothrombin complex concentrates (4F-PCC). A retrospective, multicenter review was conducted between 1/1/2014 and 7/15/2018 of patients who received 4F-PCC for reversal of dFXaI-related life-threatening hemorrhages. Total hospital reimbursements/patient were calculated based on national average MS-DRG payments adjusting for Medicare discounts. The projected cost for andexanet (based on dose and insurance) and % reimbursement/patient was compared to the actual cost of 4F-PCC. Hemostasis at 24 h (excellent/good vs. poor) and 30-day thrombotic complications were assessed. Of 126 patients who received 4F-PCC to reverse dFXaI, 46 (~ 10 per-year) met inclusion criteria. The median projected cost of andexanet was $22,120/patient, compared to $5670/patient for 4F-PCC (P < 0.001). The median hospital reimbursement was $11,492/hospitalization. The projected cost of andexanet alone would exceed the entire hospital reimbursement in 74% of patients by a median of $7604, while 4F-PCC cost exceeded the total hospital payments in 7% of patients in the same cohort (P < 0.001). Hemostasis was excellent/good in 72% of patients post-4F-PCC, compared to 82% in andexanet trials. Thromboembolic events occurred in 4% of patients following 4F-PCC versus 10% in andexanet trials. The projected cost of andexanet would exceed the national average hospital reimbursement/patient in nearly 75% of patients by over $7500/hospitalization. 4F-PCC was significantly less expensive, had lower rates of thrombosis, but also lower rates of good/excellent hemostasis compared to published data for andexanet.

Andexanet Alfa (Andexxa) Formulary Review.

Andexanet alfa, a recombinant modified human "decoy" factor Xa (FXa) protein, is the first and only available antidote approved by the Food and Drug Administration to manage life-threatening or uncontrolled bleeding associated with the anti-Xa agents. It binds to direct and indirect anti-Xa oral anticoagulants with high specificity to reverse their inhibitory effects and restore the activity of FXa. Andexanet alfa is administered via two different dosing regimens, standard and high dose, based on the specific FXa inhibitor, dose, and time since the patient's last dose of FXa inhibitor. The approval for andexanet alfa is supported by data from two phase 3 studies (ANNEXA-A, ANNEXA-R) and preliminary data from the phase 3b/4 ANNEXA-4 trial. The first study found that andexanet alfa rapidly reduced anti-Xa activity by 92%-94% in healthy volunteers taking apixaban or rivaroxaban. The ANNEXA-4 study found that the median anti-Xa activity decreased by 89%-93% in patients with major bleeding taking apixaban or rivaroxaban. However, thrombotic events occurred in 12 of 67 patients (18%) during the 30-day follow-up in ANNEXA-4. Additionally, only 40% of patients had restarted anticoagulation and, in this group, the rate of thrombotic events was 12%. Four patients had a thrombotic event within 3 days after andexanet alfa treatment. The wholesale acquisition cost of the standard dose regimen is $24,750, and the high-dose regimen is $49,500. The estimated annual drug budget of treating 10-100 patients ranges from $248K to $495M. Effective October 1, 2018, Medicare will provide an add-on payment for andexanet alfa of up to $14,063 per qualifying case to Inpatient Prospective Payment System-participating acute care hospitals. In this formulary review for a health system's pharmacy and therapeutics committee, andexanet alfa clinical trials and medication package insert were summarized and, after consulting with clinical experts from our institutions, practical recommendations for use were generated to ensure appropriate and safe use of this agent.

Safety, efficacy, and cost of four-factor prothrombin complex concentrate (4F-PCC) in patients with factor Xa inhibitor-related bleeding: a retrospective study.

Oral factor Xa (fXa) inhibitor-related bleeding is a concerning drug safety problem. There is considerable controversy surrounding available reversal strategies. The recently approved reversal agent andexanet alfa has limited data, an unclear safety profile, and imparts a substantial financial burden. This has led to the off-label use of four-factor prothrombin complex concentrates (4F-PCC) for this indication. This study aimed to assess the safety and efficacy of 4F-PCC for the management of major bleeding related to oral fXa inhibitors. This observational, retrospective study included adult patients admitted from 2014 to 2018 who received 4F-PCC (Kcentra®) for fXa inhibitor-related major bleeding. Efficacy was assessed using criteria described by Sarode et al. Secondary outcomes included the incidence of thromboembolism, mortality, and a cost analysis comparing 4F-PCC to andexanet alfa for reversal of oral fXa inhibitors. Thirty-one patients received 4F-PCC for major bleeding associated with apixaban (55%) or rivaroxaban (45%). Intracranial hemorrhage (58%) and pericardial effusion (16%) accounted for the majority of bleeding events. Most patients received a single weight-based 4F-PCC dose of 25 units/kg (38.7%) or 50 units/kg (51.6%). Effective hemostasis was achieved in 80.6% of patients. Five patients (16%) died due to acute bleeding and no thromboembolic events were observed. Administration of 4F-PCC was effective for most patients requiring emergent reversal of anticoagulation with apixaban or rivaroxaban and was associated with a low risk of thromboembolic events. Considerable cost differences limit the use of andexanet alfa and may warrant further study of 4F-PCC for fXa inhibitor reversal.

Utilizing Plasma Composition Data to Help Determine Procoagulant Dynamics in Patients with Thermal Injury: A Computational Assessment.

INTRODUCTION: The development of methods that generate individualized assessments of the procoagulant potential of burn patients could improve their treatment. Beyond its role as an essential intermediate in the formation of thrombin, factor (F)Xa has systemic effects as an agonist to inflammatory processes. In this study, we use a computational model to study the FXa dynamics underlying tissue factor-initiated thrombin generation in a small cohort of burn patients. MATERIALS AND METHODS: Plasma samples were collected upon admission (Hour 0) from nine subjects (five non-survivors) with major burn injuries and then at 48 hours. Coagulation factor concentrations (II, V, VII, VIII, IX, X, TFPI, antithrombin (AT), protein C (PC)) were measured and used in a computational model to generate time course profiles for thrombin (IIa), FXa, extrinsic tenase, intrinsic tenase and prothrombinase complexes upon a 5 pM tissue factor stimulus in the presence of 1 nM thrombomodulin. Parameters were extracted from the thrombin and FXa profiles (including max rate (MaxRIIa and MaxRFXa) and peak level (MaxLIIa and MaxLFXa)). Procoagulant potential was also evaluated by determining the concentration of the complexes at select times. Parameter values were compared between survivors and non-survivors in the burn cohort and between the burn cohort and a simulation based on the mean physiological (100%) concentration for all factor levels. RESULTS: Burn patients differed at Hour 0 (p < 0.05) from 100% mean physiological levels for all coagulation factor levels except FV and FVII. The concentration of FX, FII, TFPI, AT and PC was lower; FIX and FVIII were increased. The composition differences resulted in all nine burn patients at Hour 0 displaying a procoagulant phenotype relative to 100% mean physiological simulation (MaxLIIa (306 ± 90 nM vs. 52 nM), MaxRIIa (2.9 ± 1.1 nM/s vs. 0.3 nM/s), respectively p < 0.001); MaxRFXa and MaxLFXa were also an order of magnitude greater than 100% mean physiological simulation (p < 0.001). When grouped by survival status and compared at the time of admission, non-survivors had lower PC levels (56 ± 18% vs. 82 ± 9%, p < 0.05), and faster MaxRFXa (29 ± 6 pM/s vs. 18 ± 6 pM/s, p < 0.05) than those that survived; similar trends were observed for all other procoagulant parameters. At 48 hours when comparing non-survivors to survivors, TFPI levels were higher (108 ± 18% vs. 59 ± 18%, p < 0.05), and MaxRIIa (1.5 ± 1.4 nM/s vs. 3.6 ± 0.7 nM/s, p < 0.05) and MaxRFXa (13 ± 12 pM/s vs. 35 ± 4 pM/s, p < 0.05) were lower; similar trends were observed with all other procoagulant parameters. Overall, between admission and 48 hours, procoagulant potential, as represented by MaxR and MaxL parameters for thrombin and FXa, in non-survivors decreased while in survivors they increased (p < 0.05). In patients that survived, there was a positive correlation between FX levels and MaxLFXa (r = 0.96) and reversed in mortality (r= -0.91). CONCLUSIONS: Thrombin and FXa generation are increased in burn patients at admission compared to mean physiological simulations. Over the first 48 hours, burn survivors became more procoagulant while non-survivors became less procoagulant. Differences between survivors and non-survivors appear to be present in the underlying dynamics that contribute to FXa dynamics. Understanding how the individual specific balance of procoagulant and anticoagulant proteins contributes to thrombin and FXa generation could ultimately guide therapy and potentially reduce burn injury-related morbidity and mortality.

Differential Assessment of Factor Xa Activity and Global Blood Coagulability Utilizing Novel Dielectric Coagulometry.

An easy-to-use assessment for activated factor X (FXa) is lacking despite its pivotal role in the coagulation. Dielectric blood coagulometry (DBCM) was recently invented as a novel assessment tool for determining the whole blood coagulability by measuring the temporal change in the permittivity of blood. We previously reported that it could evaluate the global blood coagulability. This study aimed to apply the DBCM for assessing FXa activity and its inhibition by anticoagulants. We performed the DBCM analysis along with measurement of the FXa activity by a fluorometric assay in samples from healthy subjects, and identified a new index named maximum acceleration time (MAT) that had a correlation to the FXa activity. Next the DBCM analysis was performed using blood samples mixed with anticoagulants (unfractionated heparin, dalteparin, and edoxaban). Blood samples with three anticoagulants had different profiles of the temporal change in the permittivity, reflecting their different selectivity for FXa. We compared the MAT with the anti-FXa activity assay, and found that the prolongation of MAT was similarly correlated with the anti-FXa activity regardless of the type of anticoagulants. In conclusion, the DBCM has the possibility for evaluating the innate FXa activity and effect of anticoagulants focusing on their FXa inhibition.

Andexanet alfa for the treatment of hemorrhage.

INTRODUCTION: While associated life-threatening and fatal bleeding events are less frequent with the direct factor Xa inhibitors compared to vitamin K antagonists, significant concern surrounding management of major bleeds and urgent periprocedural interruption of these agents exists among clinicians. Andexanet alfa is a recombinant human factor Xa decoy protein developed in response to this clinical gap in the care of patients receiving anticoagulation with factor Xa inhibitors. Areas covered: This paper reviews results from preclinical and healthy-volunteer studies demonstrating the ability of andexanet to rapidly and reliably normalize coagulation indices in patients treated with both direct and indirect factor Xa inhibitors. An interim analysis from an ongoing phase 3/4b clinical study assessing the efficacy and safety of andexanet in patients experiencing life-threatening hemorrhage in association with factor Xa inhibitors is discussed. It also provides an overview of the major safety concerns reported in these trials which include allergic and infusion reactions, development of anti-andexanet antibodies and, importantly, thrombosis. Expert commentary: While initial reports on restoration of hemostasis and safety are promising, further study of andexanet is required to gauge its efficacy and toxicity, including a potential prothrombotic effect. Further, its use in patients requiring urgent surgery should be studied.

Assessment of an Extended Interval Fondaparinux Dosing Regimen for Venous Thromboembolism Prophylaxis in Critically Ill Patients with Severe Renal Dysfunction Using Antifactor Xa Levels.

OBJECTIVE: Pharmacologic options for venous thromboembolism (VTE) prophylaxis are often limited in critically ill patients due to thrombocytopenia and multisystem organ dysfunction. Fondaparinux offers potential advantages in the critically ill; however, it is currently contraindicated in severe renal dysfunction (SRD). We evaluated anti-factor Xa levels in critically ill patients with SRD who were receiving an extended interval dosing regimen of fondaparinux for VTE prophylaxis. METHODS: A prospective, single-arm, interventional study was conducted at two academic hospitals of the Detroit Medical Center. Eligible patients were in the intensive care unit, had an estimated creatinine clearance of less than 30 ml/minute, and had either acute kidney injury or end-stage renal disease; several patients were taking renal replacement therapy. Fondaparinux was administered at an extended interval dosing regimen of 2.5 mg subcutaneously every 48 hours. Fondaparinux peak and trough anti-factor Xa levels were obtained. Lower extremity venous duplex studies were performed at baseline and study completion to assess for deep vein thrombosis (DVT), and patients were monitored for bleeding complications. RESULTS: Thirty-two patients were enrolled. Patients received a median of four doses (interquartile range two to five) of fondaparinux. Fondaparinux peak (n=98) and trough (n=86) anti-factor Xa levels were 0.36 ± 0.18 mg/L and 0.17 ± 0.11 mg/L (mean ± SD), respectively, and were similar to levels reported in patients with normal renal function receiving conventional once-daily dosing. No lower extremity DVTs or suspected VTE events occurred. Two (6%) patients had significant bleeding events. CONCLUSIONS: In critically ill patients with SRD, an extended interval fondaparinux dosing regimen of 2.5 mg every 48 hours for VTE prophylaxis achieved peak and trough anti-factor Xa levels similar to those reported in noncritically ill patients with normal renal function receiving once-daily fondaparinux. This regimen offers an alternative for patients with SRD when heparinoids must be avoided.

New Functional Tools for Antithrombogenic Activity Assessment of Live Surface Glycocalyx.

OBJECTIVE: It is widely accepted that the presence of a glycosaminoglycan-rich glycocalyx is essential for endothelialized vasculature health; in fact, a damaged or impaired glycocalyx has been demonstrated in many vascular diseases. Currently, there are no methods that characterize glycocalyx functionality, thus limiting investigators' ability to assess the role of the glycocalyx in vascular health. APPROACH AND RESULTS: We have developed novel, easy-to-use, in vitro assays that directly quantify live endothelialized surface's functional heparin weights and their anticoagulant capacity to inactivate Factor Xa and thrombin. Using our assays, we characterized 2 commonly used vascular models: native rat aorta and cultured human umbilical vein endothelial cell monolayer. We determined heparin contents to be ≈10 000 ng/cm(2) on the native aorta and ≈10-fold lower on cultured human umbilical vein endothelial cells. Interestingly, human umbilical vein endothelial cells demonstrated a 5-fold lower anticoagulation capacity in inactivating both Factor Xa and thrombin relative to native aortas. We verified the validity and accuracy of the novel assays developed in this work using liquid chromatography-mass spectrometry analysis. CONCLUSIONS: Our assays are of high relevance in the vascular community because they can be used to establish the antithrombogenic capacity of many different types of surfaces such as vascular grafts and transplants. This work will also advance the capacity for glycocalyx-targeting therapeutics development to treat damaged vasculatures.