Anticoagulant Reversal Strategies in the Emergency Department Setting: Recommendations of a Multidisciplinary Expert Panel

Andexanet alfa versus non-specific treatments for intracerebral hemorrhage in patients taking factor Xa inhibitors - Individual patient data analysis of ANNEXA-4 and TICH-NOAC

BACKGROUND

Data comparing the specific reversal agent andexanet alfa with non-specific treatments in patients with non-traumatic intracerebral hemorrhage (ICH) associated with factor-Xa inhibitor (FXaI) use are scarce.

AIM

The study aimed to determine the association between the use of andexanet alfa compared with non-specific treatments with the rate of hematoma expansion and thromboembolic complications in patients with FXaI-associated ICH.

METHODS

We performed an individual patient data analysis combining two independent, prospective studies: ANNEXA-4 (180 patients receiving andexanet alfa, NCT02329327) and TICH-NOAC (63 patients receiving tranexamic acid or placebo ± prothrombin complex concentrate, NCT02866838). The primary efficacy outcome was hematoma expansion on follow-up imaging. The primary safety outcome was any thromboembolic complication (ischemic stroke, myocardial infarction, pulmonary embolism, or deep vein thrombosis) at 30 days. We used binary logistic regression models adjusted for baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively.

RESULTS

Among 243 participants included, the median age was 80 (IQR 75-84) years, baseline hematoma volume was 9.1 (IQR 3.4-21) mL and anti-Xa activity 118 (IQR 78-222) ng/mL. Times from last FXaI intake and symptom onset to treatment were 11 (IQR 7-16) and 4.7 (IQR 3.0-7.6) h, respectively. Overall, 50 patients (22%) experienced hematoma expansion (ANNEXA-4: n=24 (14%); TICH-NOAC: n=26 (41%)). After adjusting for pre-specified confounders (baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively), treatment with andexanet alfa was independently associated with decreased odds for hematoma expansion (aOR 0.33, 95% CI 0.13-0.80, p = 0.015). Overall, 26 patients (11%) had any thromboembolic complication within 30 days (ANNEXA-4: n=20 (11%); TICH-NOAC: n=6 (10%)). There was no association between any thromboembolic complication and treatment with andexanet alfa (aOR 0.70, 95% CI 0.16-3.12, p = 0.641).

CONCLUSION

The use of andexanet alfa compared to any other non-specific treatment strategy was associated with decreased odds for hematoma expansion, without increased odds for thromboembolic complications.

Is reversal of anticoagulants necessary in neurologically intact traumatic intracranial hemorrhage?

INTRODUCTION

Falls are the leading cause of injury in older individuals, with intracranial hemorrhage (ICH) being a common complication. Anticoagulants, such as vitamin K antagonist and direct oral anticoagulants, are increasingly utilized, and clinicians may question the necessity of reversal in patients with minor ICH, especially in the setting of increased risk of adverse events. This study aimed to identify a population of patients with minor traumatic ICH at low risk for poor-neurologic status where anticoagulant reversal may not improve outcomes.

METHODS

This retrospective cohort study utilized data accessed from 35 trauma centers from 2018 to 2021. Patients included had a preinjury anticoagulant regimen, ICH due to blunt trauma, Glasgow Coma Scale score of 15, an Abbreviated Injury Scale (AIS) head score from 2 to 4, and an AIS of ≤1 for non-head regions within 24 h of hospital arrival. Patients were excluded if they required an emergent neurosurgical procedure or were on a preinjury purinergic-P2 receptor-12 protein (P2Y12) inhibitor. The primary outcome was the rate of in-hospital mortality or hospice.

RESULTS

There were 654 patients on preinjury anticoagulation who were included with a minor traumatic ICH without neurologic deficits. Overall, 263 patients were reversed and 391 were not reversed. Twelve (4.6%) patients with in-hospital mortality or hospice were reversed compared with 19 (4.91%) patients who were not reversed (p = 0.861). A composite of hospital complications occurred in 21 (8%) reversed patients and 34 (8.7%) not reversed patients (p = 0.748). The average intensive care unit length of stay was 1.4 ± 3.4 days in the reversed group and 1.1 ± 1.8 days in the not reversed group (p = 0.069).

CONCLUSION

This study found no difference in hospital outcomes between patients with minor traumatic ICH on oral anticoagulants who were neurologically intact that were reversed versus those who were not reversed. Further studies should continue to define the subset of traumatic ICH patients who may not require reversal of anticoagulation.

Mortality after major bleeding in Asian atrial fibrillation patients receiving different direct oral anticoagulants: a nationwide, propensity score study

In this research, we assessed mortality after major bleeding events in atrial fibrillation (AF) patients taking four direct oral anticoagulants (DOACs). Drawing data from the Taiwan National Health Insurance Research Database between 2016 and 2019, we focused on AF patients on DOACs who had major bleeding episodes. Using propensity score stabilized weighting, we established four comparable pseudo-DOAC groups. Among 2770 patients (460 dabigatran, 1322 rivaroxaban, 548 apixaban, 440 edoxaban), 85.3% were prescribed low-dose regimens. The 7-day mortality rate was 9.0%, surging to 16.0% by the 30th day. Compared with dabigatran, there was a distinct divergence in 7-day mortality of factor Xa inhibitors (p = 0.012), with hazard ratios of 1.83 (95% CI 1.11-3.00, p = 0.017) for rivaroxaban, 2.13 (95% CI 1.23-3.66, p = 0.007) for apixaban, and 2.41 (95% CI 1.39-4.19, p = 0.002) for edoxaban. This pattern remained consistent when analyzing the subgroup that received lower dosages of DOACs. In conclusion, factor Xa inhibitors were associated with a significantly higher risk of 7-day mortality following major bleeding events than dabigatran among AF patients.

Use of Andexanet Alfa for Factor Xa Inhibitor Reversal in US Verified Trauma Centers: A National Survey

Direct oral factor Xa inhibitors are replacing vitamin K-dependent antagonists as anticoagulation treatment in many clinical scenarios. Trauma centers are noting an increase in patients presenting on these medications. The 2018 Food and Drug Administration approval of andexanet alfa provides an alternative anticoagulation reversal. Barriers may limit utilization of new medications including a lack of grade 1A evidence supporting the use of prothrombin complex concentrate (PCC) versus andexanet alfa and cost. To evaluate barriers of andexanet alfa utilization by trauma surgeons, a 15-question survey was conducted. There was a 9% completion rate (n = 89). The results revealed 23.5% would choose andexanet alfa as first-line treatment in children, and 25.8% as first-line treatment in adults. The majority of respondents, 64.7% and 67.4%, would use PCC preferentially in children and adults, respectively. Respondents indicated that cost burden was an overriding factor (76.3%); 42.4% cited lack of high-level efficacy data of andexanet alfa for reversal of factor Xa inhibitors. Additional double-blinded multi-institutional randomized controlled trials comparing 4F-PCC and andexanet alfa for factor Xa inhibitor reversal are needed to support efficacy especially with the increased cost associated.

Definition of factor Xa inhibitor-related, life-threatening gastrointestinal bleeding and guidance on when to use reversal therapy: A Delphi panel

Objective

To define and contextualize life-threatening gastrointestinal (GI) bleeding in the setting of factor Xa (FXa) inhibitor therapy and to derive a consensus-based, clinically oriented approach to the administration of FXa inhibitor reversal therapy.

Methods

We convened an expert panel of clinicians representing specialties in emergency medicine, gastroenterology, vascular medicine, and trauma surgery. Consensus was reached among the clinician panelists using the Delphi technique, which consisted of 2 survey questionnaires followed by virtual, real-time consensus-building exercises.

Results

Hypovolemia and hemodynamic instability were considered the most important clinical signs of FXa inhibitor-related, life-threatening GI bleeds. Clinician panelists agreed that potentially life-threatening GI bleeding should be determined on the basis of hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. Last, the panel agreed that all patients with life-threatening, FXa inhibitor-associated GI bleeding should be considered for FXa inhibitor reversal therapy; the decision to reverse FXa inhibition should be individualized, weighing the risks and benefits of reversal; and when reversal is elected, therapy should be administered within 1 h after initial emergency department evaluation, when possible.

Conclusions

Consensus-based definitions of life-threatening GI bleeding and approaches to FXa inhibitor reversal centered on hemodynamic instability, signs of shock, individual patient characteristics, and clinical judgment. The results from this Delphi panel may inform clinical decision-making for the treatment of patients experiencing GI bleeding associated with FXa inhibitor use in the emergency department setting.

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.

Lower mortality with andexanet alfa vs 4-factor prothrombin complex concentrate for factor Xa inhibitor-related major bleeding in a U.S. hospital-based observational study

Background

Well-designed studies with sufficient sample size comparing andexanet alfa vs 4-factor prothrombin complex concentrate (4F-PCC) in routine clinical practice to evaluate clinical outcomes are limited.

Objectives

To compare in-hospital mortality in patients hospitalized with rivaroxaban- or apixaban-related major bleeding who were treated with andexanet alfa or 4F-PCC.

Methods

An observational cohort study (ClinicalTrials.gov identifier: NCT05548777) was conducted using electronic health records between May 2018 and September 2022 from 354 U.S. hospitals. Inclusion criteria were age ≥18 years, inpatient admission with diagnosis code D68.32 (bleeding due to extrinsic anticoagulation), a record of use of the factor Xa inhibitors rivaroxaban or apixaban, andexanet alfa or 4F-PCC treatment during index hospitalization, and a documented discharge disposition. Multivariable logistic regression on in-hospital mortality with andexanet alfa vs 4F-PCC was performed. The robustness of the results was assessed via a supportive propensity score-weighted logistic regression.

Results

The analysis included 4395 patients (andexanet alfa, n = 2122; 4F-PCC, n = 2273). There were 1328 patients with intracranial hemorrhage (ICH), 2567 with gastrointestinal (GI) bleeds, and 500 with critical compartment or other bleed types. In the multivariable analysis, odds of in-hospital mortality were 50% lower for andexanet alfa vs 4F-PCC (odds ratio [OR], 0.50; 95% CI, 0.39-0.65; P < .01) and were consistent for both ICH (OR, 0.55; [0.39-0.76]; P < .01) and GI bleeds (OR, 0.49 [0.29-0.81]; P = .01). Similar results were obtained from the supporting propensity score-weighted logistic regression analyses.

Conclusion

In this large observational study, treatment with andexanet alfa in patients hospitalized with rivaroxaban- or apixaban-related major bleeds was associated with 50% lower odds of in-hospital mortality than 4F-PCC. The magnitude of the risk reduction was similar in ICH and GI bleeds.

Recommendations for the use of andexanet alfa in the management of bleeding in patients on oral factor Xa inhibitors in Switzerland: Guideline from the Working Party Hemostasis of the Swiss Society of Hematology

Anticoagulants are essential in preventing and treating thrombosis. Unfortunately, their use is accompanied by an enhanced risk of bleeding. Since the introduction of direct oral anticoagulants (DOACs), the risk of major bleeding has been reduced but not eliminated. Major bleeding events related to the use of factor Xa inhibitors can be challenging to manage. In recent years, four-factor prothrombin complex concentrates have been used in patients with severe bleeding taking oral direct factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). Andexanet alfa (OndexxyaTM, AstraZeneca AG) is a specially designed recombinant version of human factor Xa that acts as a decoy receptor to reverse the effects of factor Xa inhibitors. Since 2 December 2020, andexanet alfa has been used in Switzerland for adult patients receiving apixaban or rivaroxaban when reversal of anticoagulation is required because of life-threatening or uncontrolled bleeding. However, the use of andexanet alfa remains a challenge owing to its cost, the reported thrombotic complications and the fact that its efficacy mainly relates to intracranial haemorrhage. Moreover, the use of nonspecific reversal agents together with andexanet alfa is controversial. The present recommendations on the use of andexanet alfa in the management of bleeding in patients on factor Xa inhibitors in Switzerland were developed by a group of Swiss experts from the Working Party Hemostasis of the Swiss Society of Hematology. These recommendations aim to provide support to clinicians in their decision-making in the management of patients with major bleeding receiving factor Xa inhibitors.

Propensity matched analysis examining the effect of passive reversal of direct oral anticoagulants on blood loss and the need for transfusions among traumatic geriatric hip fractures

BACKGROUND

Reversal of direct oral anticoagulants (DOACs) is currently recommended prior to emergent surgery, such as surgical intervention for traumatic geriatric hip fractures. However, reversal methods are expensive and timely, often delaying surgical intervention, which is a predictor of outcomes. The study objective was to examine the effect of DOAC reversal on blood loss and transfusions among geriatric patients with hip fractures.

METHODS

This retrospective propensity-matched study across six level I trauma centers included geriatric patients on DOACs with isolated fragility hip fractures requiring surgical intervention (2014-2017). Outcomes included: intraoperative blood loss, intraoperative pRBCs, and hospital length of stay (HLOS).

RESULTS

After matching there were 62 patients (31 reversed, 31 not reversed), 29 patients were not matched. The only reversal method utilized was passive reversal (waiting ≥ 24 hours for elimination). Passively reversed patients had a longer time to surgery (mean, 43 vs. 18 hours, p < 0.01). Most patients (92%) had blood loss (90% passively reversed, 94% not reversed); the median volume of blood loss was 100 mL for both those groups, p = 0.97. Thirteen percent had pRBCs transfused (13% passively reversed and 13% not reversed); the median volume of pRBCs transfused was 525 mL for those passively reversed and 314 mL for those not reversed, p = 0.52. The mean HLOS was significantly longer for those passively reversed (7 vs. 5 days, p = 0.001).

CONCLUSIONS

Passive DOAC reversal for geriatric patients with isolated hip fracture requiring surgery may be contributing to delayed surgery and an increased HLOS without having a significant effect on blood loss or transfusions. These data suggest that passive DOAC reversal may not be necessary prior to surgical repair of isolated hip fracture.

Real-world clinical outcomes among US Veterans with oral factor xa inhibitor-related major bleeding treated with andexanet alfa or 4-factor prothrombin complex concentrate

Oral factor Xa (FXa) inhibitors significantly reduce incidence of stroke and thromboembolic events in patients with atrial fibrillation or venous thromboembolism. Due to various factors and the lack of a randomized controlled trial comparing andexanet alfa to usual care, non-specific replacement agents including 4 F-PCC are still used off-label for FXa inhibitor bleed management. Clinical and mortality data were extracted from the inpatient medical data and Veteran Affairs (VA) vital status files over the time of March 2014 through December 2020. Propensity score-weighted models were used for this retrospective cohort study using data from the Veterans Affairs Informatics and Computing Infrastructure (VINCI). The study included 255 patients (85-andexanet alfa and 170-4 F-PCC) exposed to an oral factor Xa inhibitor and hospitalized with an acute major, gastrointestinal (GI), intracranial (ICH) or other bleed. In-hospital mortality was significantly lower in the andexanet alfa cohort compared to the 4 F-PCC cohort (10.6% vs. 25.3%, p = 0.01). Propensity score-weighted Cox models reveal a 69% lower hazard of in-hospital mortality for those treated with andexanet alfa (HR 0.31, 95% CI 0.14-0.71) compared to those treated with 4 F-PCC. Additionally, those treated with andexanet alfa had a lower 30-day mortality rate and lower 30-day hazard of mortality in the weighted Cox model (20.0% vs. 32.4%, p = 0.055; HR 0.54, 95% CI 0.30-0.98) compared to those treated with 4 F-PCC. Among 255 US veterans with major bleeding in the presence of an oral factor Xa inhibitor, treatment with andexanet alfa was associated with lower in-hospital and 30-day mortality than treatment with 4 F-PCC.

A review of emerging factor XI inhibitors

INTRODUCTION

Whilst the introduction of direct oral anticoagulants (DOACs) has improved the prevention of thromboembolic events, there is still a need for safer anticoagulants. This is particularly so, for specific populations of patients, such as those with an increased bleeding risk or those with severely reduced kidney function. People with Factor XI (FXI) deficiency are at reduced risk of thromboembolic events, without an increased risk of spontaneous bleeding. FXI inhibition, therefore, presents the ideal target for novel anticoagulants.

AREAS COVERED

In this review, we provide an overview of the currently available anticoagulants and the emerging FXIa inhibitors in clinical trials. The need for availability of novel anticoagulants and the potential issues that will hinder the development and marketing of factor XIa inhibitors is also discussed.

EXPERT OPINION

Evidence suggests that FXI inhibition presents a promising drug target for novel anticoagulation therapies. The FXIa inhibitors in development have advantages over DOACs with lower renal clearance and long half-lives. Overall, FXI inhibition presents a promising target, it is likely that the clinical use of FXIa inhibitors is on the horizon.

Pharmacist authors of emergency medicine organization work products pertaining to pharmacotherapy

PURPOSE

Despite the expertise that emergency medicine (EM) pharmacists bring to multidisciplinary teams in the emergency department (ED) setting, they are not commonly present on writing groups for guidelines, policies, or task forces pertaining to EM pharmacotherapy. The purpose of this article is to quantify EM pharmacist involvement on author bylines of guidelines, position statements, and other official documents that specifically encompass EM pharmacotherapy.

METHODS

Official work products released between January 1, 2010, and May 1, 2021, were collected from the American College of Emergency Physicians (ACEP), Society for Academic Emergency Medicine (SAEM), and American Academy of Emergency Medicine (AAEM) and the table of contents of the following journals: Annals of Emergency Medicine, Academic Emergency Medicine, and Journal of Emergency Medicine. A modified Delphi approach was used to gain consensus amongst the authors on which work products to include in the initial review and which works pertained to pharmacotherapy. The primary endpoint was the percentage of pharmacists listed as authors on EM work products pertaining to pharmacotherapy.

RESULTS

Overall, 76 EM work products were identified. Forty-seven work products with a total of 248 authors contained at least 1 recommendation pertaining to pharmacotherapy. Of these 47 EM work products, 23 (49%) were from AAEM, 16 (34%) were from Annals of Emergency Medicine (published on behalf of ACEP), 5 (11%) were from Journal of Emergency Medicine (published on behalf of AAEM), and 3 (6%) were from SAEM. The median number of authors per work product was 4. There were 5 pharmacists listed on work products (2% of the total of 248 authors). Additionally, there were 9 nonpharmacist/nonphysician authors (4% of the total).

CONCLUSION

Pharmacist inclusion on author lists of recently published EM work products pertaining to pharmacotherapy is extremely low. Given their unique knowledge pertaining to EM pharmacotherapy, an effort should be made to increase inclusion of pharmacists as authors of EM work products with recommendations that pertain to pharmacotherapy.

Direct Oral Anticoagulant Reversal in the Pediatric Emergency Department

ABSTRACT

Direct oral anticoagulants have been used in the adult population for years and are being used more frequently in pediatrics. Direct oral anticoagulants are chosen preferentially because they do not require close outpatient monitoring, have an equal or better safety profile, and are easy for patients to take. Warfarin is the previous, more commonly used oral anticoagulant and acts as a vitamin K antagonist. Direct oral anticoagulants mechanism of action is different in that they directly inhibit part of the coagulation cascade accomplishing the same end goal. Given their differing mechanisms, they require alternate medications for proper reversal when concerned about overdose of life-threatening bleeds. This review will outline the most commonly used direct oral anticoagulants in pediatric populations and the supporting (mainly adult) data available for proper reversal of these medications in times of need.

Reversal of apixaban and rivaroxaban with andexanet alfa prior to invasive or surgical procedures

BACKGROUND

Outcomes following andexanet alfa reversal of factor Xa inhibitors in patients requiring urgent or emergent invasive procedures are lacking. This study aimed to describe efficacy and safety outcomes following andexanet alfa administration within 24 h of an invasive procedure.

METHODS

This single-center, observational, retrospective study included patients who received andexanet alfa within 24 h of an invasive or surgical procedure. The primary outcome was hemostatic efficacy graded as excellent, good, or poor using similar definitions to the ANNEXA-4 criteria. Secondary outcomes included hospital discharge disposition, intensive care unit (ICU) and hospital length of stay, 30-day mortality, 30-day thromboischemic event rates, and serum coagulation assay changes pre- and postreversal.

RESULTS

Forty-four patients met inclusion criteria; of these, 27 (62.8%) received apixaban and 16 (37.2%) were treated with rivaroxaban prior to admission. The indications for reversal were categorized as intracranial (n = 20 [45.5%]) or extracranial (n = 24 [54.5%]) sites. Majority of patients required emergent operative procedures (18 [40.9%]), followed by invasive device placement (10 [22.7%]) or arterial embolization (9 [20.5%]). Thirty-eight (86.4%) patients were able to be adequately graded for hemostatic efficacy. Overall, 30 (78.9%) patients achieved excellent or good hemostasis within 24 h after periprocedural administration of andexanet alfa (19 [82.6%] apixaban vs. 11 [78.6%] rivaroxaban; 12 [80.0%] intracranial events vs. 18 [78.3%] extracranial events). Discharge disposition was most often to a short- or long-term care facilities (27 [61.4%]). Thirty-day mortality and thromboischemic complications occurred in 15 (34.1%) and 12 (27.3%) patients, respectively. Prothrombin time and antifactor Xa assay results were significantly decreased after andexanet alfa administration (p < 0.05) while thromboelastogram assay values (reaction time, kinetic time, and activated clotting time) showed nonsignificant changes pre- versus postreversal.

CONCLUSION

Andexanet alfa may be used for urgent or emergent reversal of apixaban and rivaroxaban peri-procedurally with promising hemostatic outcomes. Further prospective, comparative clinical research is warranted.

Dosing Medications for Coagulopathy Reversal in Patients with Extreme Obesity

BACKGROUND

The reversal of anticoagulant or antiplatelet medications is a priority in the management of patients with severe injury with the goal of minimizing further bleeding without thrombotic complications. There are few studies, however, evaluating the dosing of reversal agents in the setting of trauma specific to patients with extreme obesity. Nevertheless, clinicians must still make decisions, balancing concerns of ongoing bleeding with excessive thrombosis.

OBJECTIVES

We describe the literature pertaining to dosing of medications used for the reversal of both drug-induced and trauma-related coagulopathy with the intent of providing a framework for clinicians to make dosing decisions in this challenging population.

DISCUSSION

Obesity is known to impact both the volume of distribution and the clearance of medications, but these changes are not usually linear with size nor are they uniform across drugs. Current strategies for dosing reversal agents in obesity include a capped dose (e.g., prothrombin complex concentrates), fixed dosages (e.g., andexanet alfa, idarucizumab, and tranexamic acid), and weight-based dosing (e.g., desmopressin). Extreme obesity, however, was not highly prevalent in the studies that have validated these dosing strategies. In fact, many of the clinical studies fail to report the average weight of the patients included.

CONCLUSION

Future studies should make efforts to increase reporting of patients with obesity included in clinical trials along with results stratified by weight class. In the meantime, doses listed in product labels should be used. Desmopressin should be dosed using either ideal body weight or a dose-capping strategy.

Performance of a Qualitative Point-of-Care Strip Test to Detect DOAC Exposure at the Emergency Department: A Cohort-Type Cross-Sectional Diagnostic Accuracy Study

An accurate point-of-care test for detecting effective anticoagulation by direct oral anticoagulants (DOACs) in emergencies is an unmet need. We investigated the accuracy of a urinary qualitative strip test (DOAC Dipstick) to detect relevant DOAC exposure in patients who presented to an emergency department. In this prospective single-center cohort-type cross-sectional study, adults on DOAC treatment were enrolled. We assessed clinical sensitivity and specificity of DOAC Dipstick factor Xa and thrombin inhibitor pads to detect DOAC plasma levels ≥30 ng/mL using urine samples as the testing matrix. Liquid chromatography coupled with tandem-mass spectrometry was used as the reference standard method for plasma and urine measurement of DOAC concentrations. Of 293 patients enrolled, 265 patients were included in the analysis, of whom 92 were treated with rivaroxaban, 65 with apixaban, 77 with edoxaban, and 31 with dabigatran. The clinical sensitivity and specificity of the dipstick on urine samples to detect ≥30 ng/mL dabigatran plasma levels were 100% (95% confidence interval [CI]: 87–100%) and 98% (95% CI: 95–99%), respectively. The sensitivity and specificity of the dipstick to detect ≥30 ng/mL factor Xa inhibitor plasma levels were 97% (95% CI: 94–99%) and 69% (95% CI: 56–79%), respectively. The DOAC Dipstick sensitively identified effective thrombin and factor Xa inhibition in a real-world cohort of patients presenting at an emergency department. Therefore, the dipstick might provide a valuable test to detect relevant DOAC exposure in emergencies, although further studies will be needed to confirm these findings.

Andexanet alfa versus four-factor prothrombin complex concentrate for the reversal of apixaban- or rivaroxaban-associated intracranial hemorrhage: a propensity score-overlap weighted analysis

BACKGROUND

Andexanet alfa is approved (FDA "accelerated approval"; EMA "conditional approval") as the first specific reversal agent for factor Xa (FXa) inhibitor-associated uncontrolled or life-threatening bleeding. Four-factor prothrombin complex concentrates (4F-PCC) are commonly used as an off-label, non-specific, factor replacement approach to manage FXa inhibitor-associated life-threatening bleeding. We evaluated the effectiveness and safety of andexanet alfa versus 4F-PCC for management of apixaban- or rivaroxaban-associated intracranial hemorrhage (ICH).

METHODS

This two-cohort comparison study included andexanet alfa patients enrolled at US hospitals from 4/2015 to 3/2020 in the prospective, single-arm ANNEXA-4 study and a synthetic control arm of 4F-PCC patients admitted within a US healthcare system from 12/2016 to 8/2020. Adults with radiographically confirmed ICH who took their last dose of apixaban or rivaroxaban < 24 h prior to the bleed were included. Patients with a Glasgow Coma Scale (GCS) score < 7, hematoma volume > 60 mL, or planned surgery within 12 h were excluded. Outcomes were hemostatic effectiveness from index to repeat scan, mortality within 30 days, and thrombotic events within five days. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated using propensity score-overlap weighted logistic regression.

RESULTS

The study included 107 andexanet alfa (96.6% low dose) and 95 4F-PCC patients (79.3% receiving a 25 unit/kg dose). After propensity score-overlap weighting, mean age was 79 years, GCS was 14, time from initial scan to reversal initiation was 2.3 h, and time from reversal to repeat scan was 12.2 h in both arms. Atrial fibrillation was present in 86% of patients. Most ICHs were single compartment (78%), trauma-related (61%), and involved the intracerebral and/or intraventricular space(s) (53%). ICH size was ≥ 10 mL in volume (intracerebral and/or ventricular) or ≥ 10 mm in thickness (subdural or subarachnoid) in 22% of patients and infratentorial in 15%. Andexanet alfa was associated with greater odds of achieving hemostatic effectiveness (85.8% vs. 68.1%; OR 2.73; 95% CI 1.16-6.42) and decreased odds of mortality (7.9% vs. 19.6%; OR 0.36; 95% CI 0.13-0.98) versus 4F-PCC. Two thrombotic events occurred with andexanet alfa and none with 4F-PCC.

CONCLUSIONS

In this indirect comparison of patients with an apixaban- or rivaroxaban-associated ICH, andexanet alfa was associated with better hemostatic effectiveness and improved survival compared to 4F-PCC. Trial registration NCT02329327; registration date: December 31, 2014.

Andexanet alfa after 4-factor PCC administration for intracranial hemorrhage: a case series

The ongoing controversy regarding optimal reversal agent for factor Xa-inhibitors is mainly due to lack of comparative data of andexanet alfa (AA) to 4-factor prothrombin complex concentrate (4F-PCC), institutional formulary restrictions, and navigation of clinical scenarios involving patients clinically worsen despite initial reversal efforts. The combination use of 4F-PCC and AA has not been evaluated in clinical trials and the outcomes of such patients with FXA-inhibitor associated intracranial hemorrhage (ICH) are unknown. A total of five patients, including four outside hospital transfers, received 4F-PCC prior to AA for FXa-inhibitor associated ICH (n = 3 apixaban, n = 2 rivaroxaban; n = 4 ICH, n = 1 TBI). The doses of 4F-PCC ranged from 25 to 60 units/kg and were administered within a range of 1.5-4.2 h prior to AA. One patient required surgical intervention with craniotomy and three patients underwent external ventricular drain placement. Two of the five patients developed an ischemic or thromboembolic complication within one week from 4F-PCC and AA administration. This case series discusses multiple unique patient cases in which 4F-PCC and AA were both administered for FXa-inhibitor associated ICH. The results highlight the potentially increased thrombotic risk associated with combination use. Ongoing post-marketing data collection of real patient case scenarios are essential to the establishment of consensus guidelines on how to prioritize initial reversal efforts and manage these patients during the course of their bleed.

Four-factor prothrombin complex concentrate plus andexanet alfa for reversal of factor Xa inhibitor-associated bleeding: Case series

DISCLAIMER

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PURPOSE

To manage factor Xa (FXa) inhibitor-associated bleeding, andexanet alfa or 4-factor prothrombin concentrate (4F-PCC) has been used to restore hemostasis. However, literature on the outcomes for patients who received both andexanet alfa and 4F-PCC is limited.

SUMMARY

We report a case series of 5 patients who received andexanet alfa plus 4F-PCC for reversal of FXa inhibitor-associated bleeding. Patients were included in this case series if they received both andexanet alfa and 4F-PCC for reversal of FXa inhibitor-associated bleeding. They were followed to either discharge or death, and in-hospital complications related to concurrent use of andexanet alfa and 4F-PCC were documented. We report an incidence of thromboembolism of 40% (2 of 5 cases) and an in-hospital mortality rate of 60% (3 of 5 cases). Taking these cases together with those in the existing literature, we found a total of 23 reported cases of safety outcomes with andexanet alfa plus 4F-PCC. The overall incidence of thromboembolism was 35% (8 of 23 cases).

CONCLUSION

This case series adds to the limited literature describing the outcomes for patients receiving andexanet alfa plus 4F-PCC. We encourage other institutions to report safety data on administering both agents.

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.

Management of Coagulopathy in Bleeding Patients

Early recognition of coagulopathy is necessary for its prompt correction and successful management. Novel approaches, such as point-of-care testing (POC) and administration of coagulation factor concentrates (CFCs), aim to tailor the haemostatic therapy to each patient and thus reduce the risks of over- or under-transfusion. CFCs are an effective alternative to ratio-based transfusion therapies for the correction of different types of coagulopathies. In case of major bleeding or urgent surgery in patients treated with vitamin K antagonist anticoagulants, prothrombin complex concentrate (PCC) can effectively reverse the effects of the anticoagulant drug. Evidence for PCC effectiveness in the treatment of direct oral anticoagulants-associated bleeding is also increasing and PCC is recommended in guidelines as an alternative to specific reversal agents. In trauma-induced coagulopathy, fibrinogen concentrate is the preferred first-line treatment for hypofibrinogenaemia. Goal-directed coagulation management algorithms based on POC results provide guidance on how to adjust the treatment to the needs of the patient. When POC is not available, concentrate-based management can be guided by other parameters, such as blood gas analysis, thus providing an important alternative. Overall, tailored haemostatic therapies offer a more targeted approach to increase the concentration of coagulation factors in bleeding patients than traditional transfusion protocols.

Hematoma Expansion and Clinical Outcomes in Patients With Factor-Xa Inhibitor-Related Atraumatic Intracerebral Hemorrhage Treated Within the ANNEXA-4 Trial Versus Real-World Usual Care

BACKGROUND AND PURPOSE

It is unestablished whether andexanet alfa, compared with guideline-based usual care including prothrombin complex concentrates, is associated with reduced hematoma expansion (HE) and mortality in patients with factor-Xa inhibitor-related intracerebral hemorrhage (ICH). We compared the occurrence of HE and clinical outcomes in patients treated either with andexanet alfa or with usual care during the acute phase of factor-Xa inhibitor-related ICH.

METHODS

Data were extracted from the multicenter, prospective, single-arm ANNEXA-4 trial (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) and a multicenter observational cohort study, RETRACE-II (German-Wide Multicenter Analysis of Oral Anticoagulant-Associated Intracerebral Hemorrhage - Part Two). HE was based on computed tomography scans performed within 36 hours from baseline imaging. Inverse probability of treatment weighting was performed to adjust for baseline comorbidities and ICH severity. Patients presenting with atraumatic ICH while receiving apixaban or rivaroxaban within 18 hours of admission were included. Patients with secondary ICH or not fulfilling the inclusion criteria for the ANNEXA-4 trial were excluded. We compared ANNEXA-4 patients, who received andexanet alfa for hemostatic treatment, with RETRACE-II patients who were treated with usual care, primarily administration of prothrombin complex concentrates. Primary outcome was rate of HE defined as relative increase of ≥35%. Secondary outcomes comprised mean absolute change in hematoma volume, as well as in-hospital mortality and functional outcome.

RESULTS

Overall, 182 patients with factor-Xa inhibitor-related ICH (85 receiving andexanet alfa versus 97 receiving usual care) were selected for analysis. There were no relevant differences regarding demographic or clinical characteristics between both groups. HE occurred in 11 of 80 (14%) andexanet alfa patients compared with 21 of 67 (36%) usual care patients (adjusted relative risk, 0.40 [95% CI, 0.20-0.78]; P=0.005), with a reduction in mean overall hematoma volume change of 7 mL. There were no statistically significant differences among in-hospital mortality or functional outcomes. Sensitivity analysis including only usual care patients receiving prothrombin complex concentrates demonstrated consistent results.

CONCLUSIONS

As compared with usual care, andexanet alfa was associated with a lower rate of HE in atraumatic factor-Xa inhibitor-related ICH, however, without translating into significantly improved clinical outcomes. A comparative trial is needed to confirm the benefit on limiting HE and to explore clinical outcomes across patient subgroups and by time to treatment.

Review of Prothrombin Complex Concentrates Use in Apixaban and Rivaroxaban Associated Intracranial Hemorrhages

STUDY OBJECTIVE

Summarize the studies evaluating the use of 4-factor prothrombin complex concentrates in the management of apixaban and rivaroxaban associated intracranial hemorrhages.

METHODS

A PubMed literature search was conducted for articles published between 2013 and 2020 which contained the following terms in their title: (1) apixaban, rivaroxaban, or factor Xa inhibitor*, and (2) prothrombin complex concentrate*.

RESULTS

Eighteen observational studies were included. When a ∼25 units/kg (range: 25-26.9 units/kg) non-activated 4 factor prothrombin complex concentrate dose was administered, the hemostatic effectiveness rates were ≥ 79% in 2/4 studies that utilized the Sarode et al criteria, in comparison to 4/5 studies that administered a 50 units/kg dose. The mortality rates were < 20% in 7/9 studies with hemostatic effectiveness rates ≥ 79%. Mortality rates were lower in the studies demonstrating higher hemostatic effectiveness rates and including patients with higher Glasgow coma scale scores and lower intracerebral hemorrhage volumes. Overall, the thromboembolic event rates were 0-18%, with 16/18 studies demonstrating rates ≤ 10%. The thromboembolic event rates were not dose or agent dependent.

CONCLUSION

Rates of hemostatic effectiveness were influenced by the definition of hemostatic effectiveness, dose administered, and patient severity. Studies suggest that higher doses may result in higher hemostatic effectiveness rates without increasing the risk of experiencing a thromboembolic event. This review may be used by providers to modify or validate their reversal strategy approach until well designed studies are available.

Four-factor Prothrombin Complex Concentrate for Reversal of Factor Xa Inhibitors versus Warfarin in Life-threatening Bleeding

INTRODUCTION

Factor Xa (fXa) inhibitor reversal for life-threatening bleeding is controversial due to a lack of high-quality evidence. The purpose of this study was to determine the hemostatic efficacy of four-factor prothrombin complex concentrate (4F-PCC) for the reversal of fXa inhibitors compared to warfarin for life-threatening bleeding.

METHODS

This was a multicenter, retrospective cohort study at two academic medical centers between January 1, 2014-December 31, 2019, which included patients who presented to the emergency department with a life-threatening bleed necessitating anticoagulation reversal with 4F-PCC. The primary endpoint was achievement of hemostatic efficacy after 4F-PCC administration.

RESULTS

Of the 525 patients who had an order for 4F-PCC during the study period, 148 patients met the criteria for inclusion (n = 48 fXa inhibitor group; n = 100 warfarin group). Apixaban (52.1%) and rivaroxaban (45.8%) were the most commonly used fXa inhibitors. Effective hemostasis was similar between groups (79.2% fXa inhibitor group vs 85% warfarin group, p = 0.38). This was consistent across all types of bleeding. Thrombotic events were rare in both groups (2% vs 3%).

CONCLUSION

This multicenter, retrospective cohort study demonstrated that using 4F-PCC for treatment of life-threatening bleeding produced effective hemostasis in patients on fXa inhibitors and warfarin.

Major publications in the critical care pharmacotherapy literature: 2019

PURPOSE

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2019.

MATERIALS AND METHODS

The Critical Care Pharmacotherapy Literature Update (CCPLU) Group screened 36 journals monthly for impactful articles and reviewed 113 articles during 2019 according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Articles with a 1A grade, including three clinical practice guidelines, six meta-analyses, and five original research trials are reviewed here from those included in the monthly CCPLU. Clinical practice guidelines on the use of polymyxins and antiarrhythmic drugs in cardiac arrest as well as meta-analyses on antipsychotic use in delirium, stress ulcer prophylaxis (SUP), and vasoactive medications in septic shock and cardiac arrest were summarized. Original research trials evaluated delirium, sedation, neuromuscular blockade, SUP, anticoagulation reversal, and hemostasis.

CONCLUSION

This clinical review and expert opinion provides summary and perspectives of clinical practice impact on influential critical care pharmacotherapy publications in 2019.

The Association of ICH Exclusion Criteria With Mortality and Disability Rates in ICH Patients Receiving 4F-PCC for Anticoagulation Reversal

BACKGROUND

Intracranial hemorrhage (ICH) exclusion criteria in the landmark four-factor prothrombin complex concentrate (4F-PCC) trial have not been incorporated into clinical practice and incremental predictive ability is unknown.

OBJECTIVES

Evaluate the association of meeting at least 1 ICH exclusion criterion with the composite end point in-hospital mortality and modified Rankin Scale [mRS] score 5 or 6. Determine the number and combination of criteria associated with poor outcomes.

METHODS

Retrospective review of adult ICH patients who received 4F-PCC for anticoagulant reversal. Patient demographics, ICH exclusion criteria, in-hospital mortality, disability, and disposition were collected. χ² Analysis and logistic regression were used to assess differences between patients with and without ICH exclusion criteria.

RESULTS

Data from 167 patients were analyzed: 103 (61.7%) met at least 1 ICH exclusion criterion. The composite end point occurred more in those with at least 1 ICH exclusion criterion (74.8% vs 39%; P < 0.0001). Presence of 2 or more ICH exclusion criteria was associated with higher odds of the composite end point, higher mRS score, and long-term care facility disposition (P < 0.0001). Glasgow Coma Scale score <7 and at least 1 other ICH exclusion criterion had negative effects on composite end point and mortality: 95% to 100% and 85% to 100%, respectively.

CONCLUSION AND RELEVANCE

Patients meeting at least 1 ICH exclusion criterion had greater death/disability compared with those who did not. More ICH exclusion criteria were associated with higher rates of death, disability, and worse disposition. These data may aid in developing optimal 4F-PCC use criteria.

Idarucizumab Reverses Dabigatran Anticoagulant Activity in Healthy Chinese Volunteers: A Pharmacokinetics, Pharmacodynamics, and Safety Study

INTRODUCTION

Idarucizumab is a humanized monoclonal antibody fragment that specifically binds to dabigatran with high affinity and reverses its anticoagulant effect. This study investigated the pharmacokinetics (PK) and pharmacodynamics (PD) of idarucizumab in healthy Chinese subjects at steady state of dabigatran and explored the effect of idarucizumab on PK and PD of dabigatran.

METHODS

Twelve subjects received dabigatran etexilate treatment alone (220 mg twice daily, b.i.d., oral). After a washout period, the 12 subjects again received dabigatran etexilate (220 mg b.i.d., oral) and idarucizumab (2.5 + 2.5 g, intravenous) 2 h after the last administration of dabigatran etexilate.

RESULTS

The geometric mean (gMean) values of area under the plasma concentration-time curve (AUC_0-∞) and maximum concentration (C_max) were 44,200 nmol h/L and 30,900 nmol/L, respectively. An amount of 35.3 μmol of idarucizumab, corresponding to 33.8% of the total dose, was excreted by urine over 72 h. The area under the effect (AUEC_above,2-12) in the presence and absence of idarucizumab was close to zero for all coagulation parameters, diluted thrombin time (dTT), ecarin clotting time (ECT), activated partial thromboplastin time (aPTT), and thrombin time (TT), which indicated the reversal of dabigatran anticoagulation by idarucizumab. There were no serious adverse events reported in this study. No subject tested positive for anti-idarucizumab antibodies.

CONCLUSION

Idarucizumab was well tolerated and no subject tested positive for anti-idarucizumab antibodies in this study. PK and PD of idarucizumab in healthy Chinese subjects at a steady state of dabigatran were comparable with those in Japanese and Caucasian subjects.

CLINICAL REGISTRATION

ClinicalTrials.gov Identifier No. NCT03086356.

Association of Reversal of Anticoagulation Preoperatively on 30-Day Mortality and Outcomes for Hip Fracture Surgery

BACKGROUND

Hip fracture is common in the elderly, many of whom are on anticoagulation. However, data are limited on outcomes with anticoagulation reversal in patients undergoing hip fracture surgery.

METHODS

Adults ≥60 years old on oral anticoagulation who underwent hip fracture surgery at 21 hospitals in Northern California from 2006 to 2016 were identified through electronic databases. Outcomes were compared among patients treated and untreated with anticoagulation reversal preoperatively.

RESULTS

Of 1984 patients on oral anticoagulation who underwent hip fracture surgery, 1943 (97.9%) were on warfarin and 41 (2.1%) were on direct oral anticoagulants. Reversal agents were administered to 1635 (82.4%). Compared to a watch-and-wait strategy, patients receiving reversal agents were more likely to be white, male, comorbid, and with higher admission and preoperative international normalized ratios (P <0.001 for all comparisons). No difference for 30-day mortality was detected between reversal vs non-reversal (7.8% vs 6.0%, respectively; hazard ratio [HR], 1.30 [95% confidence interval (CI), 0.82-2.07]). For secondary outcomes, reversal was associated with higher risk of delirium (8.6% vs 4.9%, risk ratio [RR], 1.77 [95% CI, 1.08-2.89]) and increased mean length of stay (6.4 vs 5.8 days, P <0.05). After adjustment, associations were no longer significant for delirium (RR 1.60, 95% CI, 0.97-2.65) or length of stay (mean difference 0.08, 95% CI, -0.55-0.71). No associations were detected between reversal and other secondary outcomes.

CONCLUSION

No significant associations were found between reversal agents and 30-day mortality or other outcomes in patients on oral anticoagulation who underwent hip fracture surgery. Further investigation is needed.

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.