Comparative analysis of andexanet alfa and prothrombin complex concentrate in reversing anticoagulation by rivaroxaban ex vivo.

BACKGROUND: The comparative effectiveness of the specific antidote andexanet alfa vs the nonspecific therapy four-factor prothrombin complex concentrates (4F-PCCs) as reversal agents for direct factor Xa (FXa) inhibitors in severely bleeding patients is unclear. We hypothesised that specific reversal using andexanet alfa would be more effective than a high dose of PCC (50 IU kg-1) for reversing the FXa inhibitor rivaroxaban. METHODS: The reversal potential of andexanet alfa, various 4F-PCCs, and activated PCC was investigated ex vivo in human blood anticoagulated with rivaroxaban (37.5, 75, 150, and 300 ng ml-1) using a panel of coagulation parameters, including conventional coagulation assays, thrombin generation, and a newly developed viscoelastometric device. We simulated in vivo conditions of coagulation activation and fibrin formation using flow chamber experiments of thrombogenicity potential under arterial flow conditions. RESULTS: The 4F-PCCs normalised clotting profiles only at low rivaroxaban concentrations, whereas andexanet alfa and activated PCC significantly shortened clotting time at all rivaroxaban concentrations. Only andexanet alfa restored thrombin generation to baseline. Flow chamber results showed that various 4F-PCCs concentration-dependently restored clot formation. CONCLUSIONS: In contrast to thrombin generation measurements, haemostatic reversal of rivaroxaban using high-dose 4F-PCCs exhibited similar efficacy as andexanet alfa in flow chamber experiments. The haemostatic effects of 4F-PCCs and andexanet alfa in the context of bleeding patients taking FXa inhibitors requires further study.

Andexanet alfa or prothrombin complex concentrate for acute reversal of oral factor Xa inhibitors: monitoring of antidote effects.

This study in vitro comprehensively assessed reversal of the anticoagulant effects of rivaroxaban, an oral factor Xa inhibitor, using andexanet alfa and various prothrombin complex concentrate (PCC) products in a battery of tests. In static coagulation assays, andexanet alpha outperformed PCCs except for activated PCC being more effective in standard coagulation times. However, in a flow chamber model mimicking arterial shear, both andexanet alpha and high-concentration PCC restored fibrin formation, but not platelet adhesion. In the Russell's viper venom test and anti-Xa assay, only andexanet alpha could be tested for efficacy. The antidote effects of andexanet alpha and PCCs in restoring coagulation can be qualitatively or selectively demonstrated using in vitro coagulation tests.

Reversal of pre-injury factor-Xa inhibitors with prothrombin complex concentrates in patients following traumatic brain injury.

INTRODUCTION: There is substantial debate on the best method to reverse factor Xa-inhibitors in patients following traumatic brain injury (TBI). Prothrombin complex concentrates (PCC) have been used for this indication but their role has been questioned. This study reported failure rates with PCC in patients following TBI and as a secondary objective, compared 4-factor (4 F-PCC) and activated PCC (APCC). MATERIAL AND METHODS: Consecutive patients with TBI on factor Xa-inhibitors admitted to one of two trauma centers were retrospectively identified. Patients with penetrating TBI, delays in PCC administration (>6 h), receipt of tranexamic acid, factor VIIa or no follow up CT-scan were excluded. The primary outcome was treatment failure defined as hematoma expansion > 20% from baseline for SDH, EDH or IPH, a new hematoma not present on the initial CT scan or any expansion of a SAH or IVH. Hematoma expansion was further categorized as symptomatic or asymptomatic, designated by a change in the motor GCS score, neurologic exam or change ≥ 3 in NIH Stroke Scale. Multi-variate analysis was performed. RESULTS: There were 43 patients with a mean age of 77 ± 13 years with primarily mild TBI (95%) after a ground level fall (79%). The mean dose was 41 ± 12 units/kg. Sixty percent received 4 F-PCC and 40% APCC. The incidence of treatment failure was 28% (12/43). Of the 12 patients with hematoma expansion, only 3 were symptomatic (9.3%). Hematoma expansion with 4 F-PCC and APCC were similar (27% vs. 29%,p = .859). Only sex was associated with hematoma expansion on multivariate analysis [OR (95% CI) = 6.7 (1.1 - 40.9)]. CONCLUSION: PCC was an effective option for factor Xa inhibitor reversal following TBI. The relationship between radiographic expansion and clinical expansion was poor.

Coagulation management during liver transplantation: monitoring and decision making for hemostatic interventions.

PURPOSE OF REVIEW: Rebalanced hemostasis describes the precarious balance of procoagulant and antithrombotic proteins in patients with severe liver failure. This review is aimed to discuss currently available coagulation monitoring tests and pertinent decision-making process for plasma coagulation factor replacements during liver transplantation (LT). RECENT FINDINGS: Contemporary viscoelastic coagulation monitoring systems have demonstrated advantages over conventional coagulation tests in assessing the patient's coagulation status and tailoring hemostatic interventions. There is increasing interest in the use of prothrombin complex and fibrinogen concentrates, but it remains to be proven if purified factor concentrates are more efficacious and safer than allogeneic hemostatic components. Furthermore, the decision to use antifibrinolytic therapy necessitates careful considerations given the risks of venous thromboembolism in severe liver failure. SUMMARY: Perioperative hemostatic management and thromboprophylaxis for LT patients is likely to be more precise and patient-specific through a better understanding and monitoring of rebalanced coagulation. Further research is needed to refine the application of these tools and develop more standardized protocols for coagulation management in LT.

Outcomes of 4-factor Prothrombin Complex Concentrate in Patients With Liver Disease and Nonvitamin K Antagonist-Related Coagulopathy: A Retrospective Study.

The administration of 4-factor prothrombin complex concentrate (4F-PCC) has expanded beyond its Food and Drug Administration (FDA)-approved indication for the emergent reversal of vitamin K antagonists (VKAs). Therefore, this study aimed to evaluate the risks and benefits associated with the expanded use of 4F-PCC. We conducted a single-center retrospective review of 4F-PCC administrations at our university hospital. Of the 159 patients who received 4F-PCC, 76% (n = 121) and 24% (n = 38) received it for the FDA-approved indication in the vitamin K-related coagulopathy (VKA) group and for expanded use in the nonvitamin K-related coagulopathy (nVKA) group, respectively. The expanded use of 4F-PCC was associated with a less robust reduction in the international normalized ratio (INR) (INR of -0.7 ± 1.3 vs INR of -1.6 ± 1.8, P = .002), and fewer patients in the nVKA group achieved a postadministration INR of less than1.5 (11% vs 79%, P = .001) than those in the VKA group. Furthermore, the 30-day mortality rate was significantly higher in the nVKA cohort than in the VKA cohort (42% vs 20%, P = .04). Notably, based on our data, underlying differences in the patient's comorbidities, particularly advanced liver disease, may have contributed to the observed outcome variations, including mortality rate. Therefore, factors, including comorbidities and the underlying etiology of coagulopathy, should be considered when deciding on the expanded use of 4F-PCC. Further research is needed to better understand the potential risks and benefits of 4F-PCC in expanded use scenarios, and the clinical decision to use 4F-PCC outside its FDA-approved indication should be made carefully, considering this information.

The effects of coagulation factors and their inhibitors on proliferation and migration in colorectal cancer.

BACKGROUND/AIM: Clotting factors promote cancer development. We investigated if coagulation proteins promote proliferation and migration in colorectal cancer (CRC) cell lines and whether their direct inhibitors can attenuate these effects. MATERIALS AND METHODS: DLD-1 and SW620 cells were treated with tissue factor (0, 50, 100 and 500 pg/mL ± 10 µg/mL 10H10 [anti-tissue factor antibody]), thrombin (0.0, 0.1, 1.0 and 10.0 U/mL ± 0.5 µM dabigatran [thrombin inhibitor]) and Factor Xa, FXa (0.0, 0.1, 1.0 and 10.0 U/mL ± 100 ng/mL rivaroxaban [FXa inhibitor]) and their effects on proliferation and migration were quantified using the PrestoBlue® and transwell migration assays, respectively. RESULTS: Thrombin increased proliferation from 48 h treatment compared to its control (48 h 6.57 ± 1.36 u vs. 2.42 ± 0.13 u, p = 0.001, 72 h 9.50 ± 1.54 u vs. 4.50 ± 0.47 u, p = 0.004 and 96 h 10.77 ± 1.72 u vs. 5.57 ± 0.25 u, p = 0.008). This increase in proliferation was attenuated by dabigatran at 72 h (2.23 ± 0.16 u vs. 3.26 ± 0.43 u, p = 0.04). Tissue factor (0 pg/mL 20.7 ± 1.6 cells/view vs. 50 pg/mL 32.4 ± 1.9 cells/view, p = 0.0002), FXa (0.0 U/mL 8.9 ± 1.1 cells/view vs. 10.0 U/mL 17.7 ± 1.7 cells/view, p < 0.0001) and thrombin (0.0 U/mL 8.9 ± 1.3 cells/view vs. 10.0 U/mL 20.2 ± 2.0 cells/view, p < 0.0001) all increased migration compared to their controls. However, their direct inhibitors did not attenuate these increases. CONCLUSION: Thrombin, FXa and TF all increase migration in CRC in vitro. Thrombin induced increase in proliferation is abrogated by dabigatran. Dabigatran may have potential as an anti-cancer therapy in CRC.

Hemostatic efficacy of four factor prothrombin complex concentrate in intracerebral hemorrhage patients receiving warfarin vs. factor Xa inhibitors.

INTRODUCTION: 4-F PCC is administered for reversal of factor Xa inhibitor-associated coagulopathy despite a lack of quality evidence demonstrating hemostatic efficacy. The aim of this study was to evaluate the hemostatic efficacy of 4-F PCC in intracerebral hemorrhage patients who received factor Xa inhibitors versus warfarin. MATERIALS AND METHODS: This was a multi-center, retrospective, observational cohort study at a large healthcare system. Patients taking warfarin received 4-F PCC 25-50 units/kg based on the presenting INR, while patients taking a factor Xa inhibitor received 35 units/kg. The primary outcome was the percentage of patients with good or excellent hemostatic efficacy as assessed by modified Sarode scale, with neurologic outcomes assessed as a secondary endpoint. Patients were included in the primary outcome population if they had a repeat CT scan within 24 h. RESULTS: One hundred fifty-seven patients were included in the primary outcome population; [warfarin (n = 76), factor Xa inhibitors (n = 81)]. Hemostatic efficacy was 83 % in the warfarin group versus 75 % in the factor Xa inhibitor group (p = 0.24). The hemostatic efficacy risk difference between the groups was 7.6 % (95 % CI 5.1 %, 20.2 %). Good neurologic outcome (mRS 0-2) at discharge was 17 % in warfarin patients versus 12 % in the factor Xa inhibitor patients (p = 0.40). CONCLUSIONS: There was no significant difference in hemostatic efficacy or clinical outcomes between patients taking warfarin or a factor Xa inhibitor following reversal with 4-F PCC. This study provides further support that 4-F PCC can be used for the reversal of factor Xa inhibitor-associated coagulopathy.

Safety of FEIBA and emicizumab (SAFE): Dose escalation study evaluating the safety of in vivo administration of activated prothrombin complex concentrate in haemophilia A patients on emicizumab.

INTRODUCTION: Emicizumab is a humanized bispecific monoclonal antibody licensed for patients with severe haemophilia A. Breakthrough bleeding still occurs in patients on emicizumab and can be managed with recombinant factor VIIa (rFVIIa) or activated prothrombin complex concentrate (aPCC). Thrombotic events were reported when patients on emicizumab received concomitant aPCC at relatively high doses. We studied the effect of infusing various doses of aPCC to patients on emicizumab. MATERIAL AND METHODS: Nine patients with severe haemophilia A with inhibitors who are on emicizumab were recruited to participate. Patients were infused with varying doses of aPCC in vivo. Samples were tested with thrombin generation (TG) assay. RESULTS: In the current in vivo arm of the study four out of nine patients reached the highest dose, 75 U/kg of aPCC and six out of nine patients were actually eligible for the highest dose. In the previous in vitro arm of the study seven out of eight patients reached the normal plasma with spiking aPCC at a very low concentration equivalent to 5 U/kg. CONCLUSION: The in vitro portion of the study demonstrated that clinically relevant concentrations of aPCC resulted in excessive TG, however, in vivo administration of aPCC to the same patients demonstrated that most of the patients had normal TG at the approved doses of aPCC. In the management of breakthrough bleeding clinicians should heed the boxed warning for concomitant use of emicizumab and aPCC, however, should also be aware that low doses of aPCC may not result in sufficient TG.

Keel venom: Rhabdophis subminiatus (Red-Necked Keelback) venom pathophysiologically affects diverse blood clotting pathways.

Venoms are evolutionary novelties that have real-world implications due to their impact upon human health. However, relative to the abundant studies of elapid and viperid snake venoms, fewer investigations have been undertaken on those of rear-fanged snakes as they are more problematic for obtaining venom. While most rear-fanged venomous snakes are not considered to be of great medical importance, several species are capable of producing fatalities. Most notable among these are snakes from the genus Rhabdophis, the Asian "keelback" snakes. Prior work have described potent procoagulant toxicity suggesting Factor X and prothrombin activation, but did not investigate the ability to activate other clotting factors. Here we show that in addition to activating both Factor X and prothrombin (with prothrombin twice that of FX), the venom of Rhabdophis subminiatus is able to more potently activate Factor VII (ten times that of prothrombin), while also activating FXII and FIX equipotently to prothrombin, and with FXI also activated but at a much lower level. The ability to activate FVII represents a third convergent evolution of this trait. The Australian elapid clade of [Oxyuranus (taipans) + Pseudonaja (brown snakes)] was the first identified to have evolved this trait. and only recently was it shown to be independently present in another lineage (the Central American viperid species Porthidium volcanicum). In addition, the abilities to activate FXI and FXII are also convergent between R. subminiatus and P. volcanicum, but with R. subminiatus being much more potent. By testing across amphibian, avian, and mammalian plasmas we demonstrate that the venom is potently procoagulant across diverse plasma types. However, consistent with dietary preference, R. subminiatus venom was most potent upon amphibian plasma. While a Rhabdophis antivenom is produced in Japan to treat R. tigrinus envenomings, it is scarce even within Japan and is not exported. As this genus is very wide-ranging in Asia, alternate treatment options are in need of development. Hence we tested the ability of candidate, broad-spectrum enzyme inhibitors to neutralize R. subminiatus venom: marimastat was more effective than prinomastat but both marimastat and prinomastat were significantly more effective than DMPS (2,3-Dimercapto-1-propanesulfonic acid). The findings of this study shed light on the evolution of these fascinating rear-fanged snakes as well as explored their systemic effects upon blood coagulation and point to potential treatment options for the rare, but potentially lethal encounters.

Characterization of 2 Different Prothrombin Complex Concentrates by Different Hemostatic Assays in an In Vitro Hemodilution Model.

BACKGROUND: Viscoelastically guided coagulation factor concentrate-based algorithms for the treatment of trauma-induced coagulopathy include the administration of prothrombin complex concentrates (PCCs). However, the exact role of PCC preparations in this context is a matter of debate. Particularly, the ideal diagnostic trigger for their administration and potential differences between heparin-containing and heparin-free preparations remain unclear. We investigated the hypothesis that 2 different PCCs might have distinct influences on in vitro blood coagulation. METHODS: We conducted a direct comparison of 2 commercially available PCC preparations (the heparin-containing Beriplex P/N and the heparin-free Cofact) in an in vitro hemodilution model. Sole fibrinogen substitution served as the control group. To characterize the hemostatic changes, we utilized conventional coagulation tests, a thrombin generation assay (TGA), and 2 different viscoelastic hemostatic assays (VHAs; ROTEM delta and ClotPro). RESULTS: Irrespective of the diagnostic assay used, no significant differences between the 2 PCC groups were observed. Fibrinogen levels remained stable from the baseline throughout every dilution level. The control group already showed an increased endogenous thrombin potential (ETP; nM·L -1 ·min -1 ) at all dilution levels compared to baseline (baseline, 2829.4 (432.8); 40% dilution, 4211.7 (391.6); 60% dilution, 4290.9 (300.8); 80% dilution, 3861.4 (303.5); all P < .001). Spiking with both PCC preparations led to a further-pronounced thrombin elevation in comparison to the control group (ETP at 40% dilution, PCC1: 4913.3 [370.2], PCC2: 4988.1 [265.7]; 60% dilution, PCC1: 5174.5 [234.7], PCC2: 5390.4 [334.9]; 80% dilution, PCC1: 5253.8 [357.9], PCC2: 5392.6 [313.4]; all P < .001). Conventional coagulation tests did not mirror the TGA results. Despite increased thrombin generation, prothrombin time was significantly prolonged at all dilution levels for the control group, and both PCC groups exhibited significant prolongations at the 60% and 80% dilution levels (all P < .001) compared to baseline. Similarly, VHA did not depict the thrombin elevation. Furthermore, descriptive analyses revealed relevant differences between the 2 VHA devices, particularly at baseline. CONCLUSIONS: Both PCC preparations (ie, irrespective of heparin content) induced significant elevation of thrombin generation, which was not depicted by conventional coagulation tests or VHA. Our in vitro results suggest that diagnostic assays routinely used to guide PCC administration might not adequately reflect thrombin generation in bleeding patients.

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.

Evaluation of fixed-dose versus variable-dose prothrombin complex concentrate for warfarin reversal.

INTRODUCTION: The purpose was to compare hemostatic efficacy rates for fixed- and variable-dose four-factor prothrombin complex concentrate (4F-PCC) for warfarin reversal. MATERIAL AND METHODS: Retrospective study of patients with non-intracranial major bleeding or undergoing emergent surgery/procedure who received 4F-PCC for warfarin reversal from September 2013 through August 2020. Hemostatic efficacy at 48 h following fixed- or variable-dose 4F-PCC was evaluated using modified International Society on Thrombosis and Hemostasis (ISTH) criteria for major bleeding. Secondary outcomes included occurrence of post-4F-PCC INR ≤ 1.5, in-hospital mortality, time to 4F-PCC administration, and 4F-PCC cost. Univariate analyses were completed and logistic regression used to identify patient-specific factors associated with hemostatic efficacy. RESULTS: A total of 265 patients, 90 (34%) fixed- and 175 (66%) variable-dose 4F-PCC, were included. Hemostatic efficacy was achieved in 34 (37.8%) and 38 (21.7%) in fixed- and variable-dose groups, respectively, p = 0.005. Achievement of INR ≤ 1.5 occurred in 55 (62.5%) in the fixed- and 120 (69.4%) in the variable-dose groups, p = 0.26, and there was no in-hospital mortality difference. Time to administration was a mean 20 min faster and cost was reduced by a mean $1881/dose in the fixed-dose group. The unadjusted odds of achieving hemostatic efficacy was 2.27 among those receiving fixed-dose compared to variable-dose 4F-PCC (95% CI 1.30, 3.98); this was not confounded by initial INR or patient weight. CONCLUSION: Fixed-dose 4F-PCC is associated with a higher likelihood of achieving hemostatic efficacy, quicker time to administration, and reduced cost compared to variable-dose 4F-PCC for warfarin reversal.

Impact of Factor Xa Inhibitor Reversal with Prothrombin Complex Concentrate in Patients with Traumatic Brain Injuries.

BACKGROUND: Anticoagulant use prior to trauma has been associated with increased incidence of traumatic brain injury (TBI), intracranial hemorrhage (ICH) progression, and mortality. Prothrombin complex concentrates (PCCs) are commonly used as off-label treatments for factor Xa inhibitor-associated life-threatening hemorrhage. At this time, there is no consensus regarding appropriate indication, target dose, or outcomes of PCC administration in patients presenting with traumatic ICH. This study seeks to evaluate the impact of reversal with PCC on hemorrhage progression and outcomes in patients with TBI on preinjury factor Xa inhibitors. METHODS: This single-center retrospective cohort study included patients ≥ 18 years presenting with an acute TBI of any severity on apixaban or rivaroxaban from September 1, 2016, to September 1, 2019. Patients were grouped on the basis of receipt of PCCs for reversal (i.e., reversal or no reversal). Exclusion criteria included spontaneous ICH or known coagulopathy. Propensity score matching was conducted with the following variables: age, Abbreviated Injury Scale (head) score, and Charlson Comorbidity Index score. The primary outcome was hemorrhage stability within 48 h. Secondary outcomes included degree of hemorrhage progression, in-hospital mortality, discharge disposition, and incidence of thromboembolic events. RESULTS: Of the 115 patients meeting inclusion criteria, 84 were included in the propensity score matched data set. Baseline characteristics, comorbidities, and TBI severity were similar. The majority of patients in the reversal group (35 [83.3%]) and the no reversal (NR) group (40 [95.2%]) experienced a mild TBI (admission Glasgow Coma Scale score of 14 to 15). In the reversal group, patients received 34.3 units/kg activated PCC, 30.5 units/kg four-factor PCC, or 54.9 units/kg four-factor PCC and activated PCC on average. There was no difference observed in the incidence of hemorrhage progression (10.8% NR vs. 15.0% reversal; p = 0.739) or in median change in ICH volume (0 mL NR vs. 1 mL reversal; p = 0.2199) between groups. Additionally, reversal did not affect in-hospital mortality (3 [7.1%] NR vs. 4 [9.5%] reversal; p > 0.999). One patient in the reversal group developed a deep vein thrombosis (DVT) during the hospitalization; however, this did not result in a statistically significant difference in the occurrence of DVT (p > 0.999). CONCLUSIONS: This study demonstrated that PCC used for the treatment of factor Xa inhibitor-associated ICH related to mild TBI did not significantly impact the incidence or degree of hemorrhage progression, and PCC treatment did not result in increased thromboembolic events.

Comparative hemostatic efficacy of 4F-PCC in patients with intracranial hemorrhage on factor Xa inhibitors versus warfarin.

OBJECTIVE: Patients experiencing an intracranial hemorrhage (ICH) on oral anticoagulants often require rapid reversal. This study evaluated patients taking factor Xa inhibitors or warfarin that received reversal with 4-factor prothrombin complex concentrate (4F-PCC) for an ICH. The objective of the study was to determine if the efficacy of 4F-PCC for the reversal of factor Xa inhibitors is noninferior to its use in warfarin reversal in patients with ICH. METHODS: This was a retrospective, single center, noninferiority trial. Patients presenting to the emergency department with ICH were divided into two cohorts: those taking factor Xa inhibitors versus those taking warfarin. In each cohort, patients received anticoagulation reversal with weight-based 4F-PCC. The primary endpoint was hemostatic efficacy defined as ≤20% expansion in hematoma volume on repeat computed tomography imaging. A pre-specified noninferiority margin of -10% was selected to evaluate the difference between groups for the primary endpoint. RESULTS: A total of 221 patients were included in the study (factor Xa inhibitors, n = 87; warfarin, n = 134). Effective hemostasis was achieved in 70 patients (81%) on factor Xa inhibitors compared to 111 patients (83%) on warfarin, (-2.4% difference, [95% confidence interval, -12.87 to 8.12]; p = 0.654). There was no statistically significant difference between groups with regards to the primary outcome; however, the use of 4F-PCC in factor Xa inhibitor reversal was not noninferior when compared to 4F-PCC use for warfarin reversal. Hospital length of stay and discharge disposition were similar between cohorts. CONCLUSIONS: The efficacy of 4F-PCC in reversing factor Xa inhibitor-related ICH compared to warfarin-related ICH was not significantly different between groups; however, these results did not prove noninferiority. Further study is warranted to delineate 4F-PCC's role in reversing factor Xa inhibitors in patients with ICH.

High versus low fixed-dose four factor-prothrombin complex concentrate for warfarin reversal in patients with intracranial hemorrhage.

BACKGROUND: Four-factor prothrombin complex concentrate 4F-PCC is the standard of care for warfarin reversal in patients with major bleed or requiring urgent surgery. Although the 4F-PCC dose is weight and international normalized ratio (INR) based, for practical purposes, a fixed-dose approach has been explored, especially for rapid reversal. We report our experience using two different fixed-dose 4F-PCC for warfarin reversal in patients presenting with intracranial hemorrhage (ICH). STUDY DESIGN AND METHODS: We completed a retrospective chart review comparing high (4000 units) versus low (2000 units) dose 4F-PCC by evaluating patient characteristics, laboratory data, and pre-and post-4F-PCC brain imaging. RESULTS: There was no significant difference between patient characteristics or INR correction (≤1.5) between the two groups. Eighty percent (12/15) of patients who received the low dose 4F-PCC had either improved or stable brain imaging as compared to 88% (14/16) of patients who received the high dose PCC. When the eight patients (4 from each arm of the study) who required neurosurgery were excluded, only two patients in each arm had worse imaging after 4F-PCC. CONCLUSION: There was no significant difference between the INR correction and the brain imaging changes in patients with an ICH who received either the high or the low fixed-dose 4F-PCC for warfarin reversal.

Andexanet alfa versus four-factor prothrombin complex concentrate for the reversal of apixaban- or rivaroxaban-associated intracranial hemorrhages.

BACKGROUND: Existing research recommends either andexanet alfa (AA) or four-factor prothrombin complex concentrate (4F-PCC) as an antidote for major bleeding events due to apixaban or rivaroxaban. Currently, there is limited published research that directly compares the risks and benefits of the two agents in patients with oral factor Xa inhibitor related traumatic and spontaneous intracerebral hemorrhages. Additional head-to-head data is needed to support favoring either AA or 4F-PCC when it comes to efficacy, safety, and cost. METHODS: A retrospective chart review was conducted to assess patients admitted to a multi-center healthcare system and a stand-alone teaching hospital in central Florida from June 2016 to December 2020. Patients included in the study were at least 18 years of age, taking apixaban or rivaroxaban prior to admission, had radiographical evidence of an intracranial hemorrhage, and received either AA or 4F-PCC as a reversal agent. The primary outcome analyzed was the level of excellent hemostasis achieved, based on a standardized rating system for effective hemostasis defined by the International Society of Thrombosis and Hemostasis (ISTH), after administration of AA or 4F-PCC. Secondary outcomes analyzed included changes in the initial hemorrhage volume as reported on computed tomography (CT) scan and at 12 to 24 h post treatment, rate of thromboembolic events, rate of inpatient mortality, and total cost of treatment after AA or 4F-PCC administration. RESULTS: A total of 109 patients were included in the study with 47 in the AA group (43.1%) and 62 in the 4F-PCC group (56.9%). There were no statistically significant differences between AA and 4F-PCC in terms of the primary and secondary outcomes with the exception of total cost of treatment. The level of excellent hemostasis achieved after reversal administration of AA was seen in 27 patients (71.1%) and 41 patients (70.7%) after 4F-PCC administration (p = 1, p adjusted = 0.654 after controlling for age, ICH score, regional mass effect, and midline shift). There was no statistically significant difference in the median percentage change in hemorrhagic volume from baseline to 12-24 h after reversal treatment (0 [-0.17--0.24] vs. 0 [-0.021-0.29], p = 0.439, adjusted p = 0.601) in the AA and 4F-PCC groups, respectively. The total incidence of thromboembolic events (4 [8.5%] vs. 6 [9.7%], p = 1, adjusted p = 0.973) and rate of inpatient mortality was similar between the two groups (16 [34.0%] vs. 13 [21.0%], p = 0.134, adjusted p = 0.283). A statistically significant difference was observed with the total cost of reversal treatment: $23,602 for treatment with AA and $6692 for treatment with 4F-PCC. CONCLUSIONS: No statistically significant differences were identified in primary or secondary outcomes between the two agents with the exception of total treatment cost. There is insufficient evidence based on this study to recommend AA over 4F-PCC for patients with intracranial hemorrhages associated with the use of apixaban or rivaroxaban.

FFP maintains normal coagulation while Kcentra induces a hypercoagulable state in a porcine model of pulmonary contusion and hemorrhagic shock.

BACKGROUND: Moderate injury can lead to a coagulopathy. Fresh frozen plasma (FFP) corrects coagulopathy by means of a balanced array of clotting factors. We sought to compare the late effects of FFP and a prothrombin complex concentrate (PCC) on the coagulopathy of trauma using a porcine model of pulmonary contusion (PC) and hemorrhagic shock (HS) designed to evaluate the organ protective effects of these treatments. METHODS: Female Yorkshire swine (40-50 kg) were randomized to receive PC + HS or control (instrumented and uninjured). A blunt PC was created using a captive bolt gun. To induce HS, a liver crush injury was performed. Eighty minutes after injury, swine were treated with 25 U·kg-1 PCC, 1 U FFP, or 50 mL lactated Ringer's vehicle in a blinded manner. Arterial blood samples were drawn every 6 hours. Swine were euthanized 48 hours postinjury. Data were analyzed by Pearson χ2, analysis of variance and Kruskal-Wallis tests with Tukey's or Mann-Whitney U tests for post hoc analysis. RESULTS: Twenty-seven swine received PC + HS, 3 groups of 9 per group received PCC, FFP, or vehicle. Nine were noninjured controls. When compared with control, PC + HS swine had significantly shortened R time at 6 hours, 36 hours, and 42 hours, decreased LY30 at 12 hours, shortened K time at 30 hours and reduced α angle at 42 hours. PC + HS swine showed significant differences between treatment groups in K and α angle at 3 hours, LY30 at 12 hours and 18 hours, and MA at 12 hours, 18 hours, and 30 hours. Post hoc analysis was significant for higher α angle in PCC versus vehicle at 3 hours, higher MA in vehicle versus PCC at 12 hours and 18 hours, and higher LY30 in PCC versus vehicle at 18 hours (p < 0.012) with no significant differences between FFP and vehicle. CONCLUSION: Severe injury with HS induced a coagulopathy in swine. While FFP maintained normal coagulation following injury, PCC induced more rapid initial clot propagation in injured animals.

Effects of replacement therapies with clotting factors in patients with hemophilia: A systematic review and meta-analysis.

BACKGROUND: Different prophylactic and episodic clotting factor treatments are used in the management of hemophilia. A summarize of the evidence is needed inform decision-making. OBJECTIVE: To compare the effects of factor replacement therapies in patients with hemophilia. METHODS: We performed a systematic search in PubMed, Central Cochrane Library, and Scopus. We included randomized controlled trials (RCTs) published up to December 2020, which compared different factor replacement therapies in patients with hemophilia. Random-effects meta-analyses were performed whenever possible. The certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The study protocol was registered in PROSPERO (CRD42021225857). RESULTS: Nine RCTs were included in this review, of which six compared episodic with prophylactic treatment, all of them performed in patients with hemophilia A. Pooled results showed that, compared to the episodic treatment group, the annualized bleeding rate was lower in the low-dose prophylactic group (ratio of means [RM]: 0.27, 95% CI: 0.17 to 0.43), intermediate-dose prophylactic group (RM: 0.15, 95% CI: 0.07 to 0.36), and high-dose prophylactic group (RM: 0.07, 95% CI: 0.04 to 0.13). With significant difference between these subgroups (p = 0.003, I2 = 82.9%). In addition, compared to the episodic treatment group, the annualized joint bleeding rate was lower in the low-dose prophylactic group (RM: 0.17, 95% CI: 0.06 to 0.43), intermediate-dose prophylactic group (RM of 0.14, 95% CI: 0.07 to 0.27), and high-dose prophylactic group (RM of 0.08, 95% CI: 0.04 to 0.16). Without significant subgroup differences. The certainty of the evidence was very low for all outcomes according to GRADE methodology. The other studies compared different types of clotting factor concentrates (CFCs), assessed pharmacokinetic prophylaxis, or compared different frequencies of medication administration. CONCLUSIONS: Our results suggest that prophylactic treatment (at either low, intermediate, or high doses) is superior to episodic treatment for bleeding prevention. In patients with hemophilia A, the bleeding rate seems to have a dose-response effect. However, no study compared different doses of prophylactic treatment, and all results had a very low certainty of the evidence. Thus, future studies are needed to confirm these results and inform decision making.

Variations and obstacles in the use of coagulation factor concentrates for major trauma bleeding across Europe: outcomes from a European expert meeting.

PURPOSE: Trauma is a leading cause of mortality, with major bleeding and trauma-induced coagulopathy (TIC) contributing to negative patient outcomes. Treatments for TIC include tranexamic acid (TXA), fresh frozen plasma (FFP), and coagulation factor concentrates (CFCs, e.g. prothrombin complex concentrates [PCCs] and fibrinogen concentrate [FCH]). Guidelines for TIC management vary across Europe and a clear definition of TIC is still lacking. METHODS: An advisory board involving European trauma experts was held on 02 February 2019, to discuss clinical experience in the management of trauma-related bleeding and recommendations from European guidelines, focusing on CFC use (mainly FCH). This review summarises the discussions, including TIC definitions, gaps in the guidelines that affect their implementation, and barriers to use of CFCs, with suggested solutions. RESULTS: A definition of TIC, which incorporates clinical (e.g. severe bleeding) and laboratory parameters (e.g. low fibrinogen) is suggested. TIC should be treated immediately with TXA and FCH/red blood cells; subsequently, if fibrinogen ≤ 1.5 g/L (or equivalent by viscoelastic testing), treatment with FCH, then PCC (if bleeding continues) is suggested. Fibrinogen concentrate, and not FFP, should be administered as first-line therapy for TIC. Several initiatives may improve TIC management, with improved medical education of major importance; generation of new and stronger data, simplified clinical practice guidance, and improved access to viscoelastic testing are also critical factors. CONCLUSIONS: Management of TIC is challenging. A standard definition of TIC, together with initiatives to facilitate effective CFC administration, may contribute to improved patient care and outcomes.