Rapid reversal of oral anticoagulation with warfarin by a prothrombin complex concentrate (Beriplex): efficacy and safety in 42 patients

Rapid administration of Kcentra® during cardiopulmonary arrest

We present a case of cardiopulmonary arrest secondary to rivaroxaban related oropharyngeal hemorrhage, which required rapid intravenous (IV) push administration of 4-factor prothrombin complex concentrate (4F-PCC). Manufacturers recommend administering 4F-PCC IV at a rate of 0.12 mL/kg/min (approximately 3 units/kg/min) up to a maximum rate of 8.4 mL/min (approximately 210 units/min) [1]. The concern with rapid administration is increased potential for thromboembolic complications. There have been small studies assessing infusion rates greater than the manufacturer's recommendation with few reported thromboembolic events [2-5]. Our patient was an 81-year-old female presenting to the emergency department (ED) with sudden onset oropharyngeal hemorrhage. The patient had a pertinent history of oral and esophageal cancer and was prescribed rivaroxaban 20 mg once daily for treatment of deep vein thrombosis. Within moments of the patient arriving, she produced a large volume of blood from her nose and mouth. The source of the bleeding could not be determined, and as suctioning was attempted to clear her airway, the patient became unresponsive and pulseless. Advanced Cardiac Life Support (ACLS) procedures were initiated and 1000 mg of tranexamic acid were administered. Once the patient's active medication list was discovered, 2000 units of 4F-PCC was given as an IV push over roughly 20 s. Bleeding was controlled enough to secure the patient's airway within 5 min after 4F-PCC administration and subsequently return of spontaneous circulation was achieved. Unfortunately, the patient suffered a poor neurologic outcome and the family withdrew care after discussion with the treatment team and the patient's oncologist. This case report demonstrates rapid administration of 4F-PCC may be an effective intervention to treat immediately life threatening rivaroxaban related bleeding.

Combination Therapy Using Prothrombin Complex Concentrate and Vitamin K in Anticoagulated Patients with Traumatic Intracranial Hemorrhage Prevents Progressive Hemorrhagic Injury: A Historically Controlled Study

Warfarin remains crucially involved in the treatment of patients at thrombotic or thromboembolic risk. However, warfarin increases the mortality rate among patients with traumatic intracranial hemorrhage (TICH) through progressive hemorrhagic injury (PHI). Therefore, a rapid anticoagulation reversal could be required in patients with TICH to prevent PHI. Differences in the warfarin reversal effect between combination therapy of prothrombin complex concentrate (PCC) with vitamin K (VK) and VK monotherapy remain unclear. However, studies have reported that PCC has greater effectiveness and safety for warfarin reversal compared with fresh frozen plasma (FFP). This retrospective study aimed to evaluate the warfarin reversal effects of combination therapy of PCC with VK and VK monotherapy on TICH. We compared the clinical outcomes between the periods before and after the PCC introduction in our hospital. There were 13 and 7 patients who received VK monotherapy and PCC with VK, respectively. PHI predictors were evaluated using univariate regression analyses. Warfarin reversal using PCC had a significant negative association with PHI (odds ratio: 0.03, 95% confidence interval: 0.00-0.41, P = 0.004). None of the patients presented with thrombotic complications. Warfarin reversal through a combination of PCC with VK could be more effective for inhibiting post-trauma PHI compared with VK monotherapy. This could be attributed to a rapid and stable warfarin reversal. PCC should be administered to patients with TICH taking warfarin for PHI prevention.

A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures

BACKGROUND

Reversal of therapeutic anticoagulation prior to emergency neurosurgical procedures is required in the setting of intracranial hemorrhage. Multifactor prothrombin complex concentrate (PCC) promises rapid efficacy but may increase the probability of thrombotic complications compared to fresh frozen plasma (FFP).

OBJECTIVE

To compare the rate of thrombotic complications in patients treated with PCC or FFP to reverse therapeutic anticoagulation prior to emergency neurosurgical procedures in the setting of intracranial hemorrhage at a level I trauma center.

METHODS

Sixty-three consecutive patients on warfarin therapy presenting with intracranial hemorrhage who received anticoagulation reversal prior to emergency neurosurgical procedures were retrospectively identified between 2007 and 2016. They were divided into 2 cohorts based on reversal agent, either PCC (n = 28) or FFP (n = 35). The thrombotic complications rates within 72 h of reversal were compared using the χ2 test. A multivariate propensity score matching analysis was used to limit the threat to interval validity from selection bias arising from differences in demographics, laboratory values, history, and clinical status.

RESULTS

Thrombotic complications were uncommon in this neurosurgical population, occurring in 1.59% (1/63) of treated patients. There was no significant difference in the thrombotic complication rate between groups, 3.57% (1/28; PCC group) vs 0% (0/35; FFP group). Propensity score matching analysis validated this finding after controlling for any selection bias.

CONCLUSION

In this limited sample, thrombotic complication rates were similar between use of PCC and FFP for anticoagulation reversal in the management of intracranial hemorrhage prior to emergency neurosurgical procedures.

Prothrombin complex concentrate for vitamin K antagonist reversal in acute bleeding settings: efficacy and safety

Introduction: Current guidelines recommend the administration of prothrombin complex concentrate in combination with vitamin K for normalization of coagulation in patients presenting with vitamin K antagonist-associated major bleeding, but until recently no adequately powered comparative trials had been conducted to support these recommendations. In this article, the authors review the evidence from studies assessing prothrombin complex concentrate treatment in these patients. Areas covered: A PubMed search (spanning January 1900 to September 2018) was conducted using the following search terms: prothrombin complex concentrate* AND (warfarin or (vitamin K antagonist*)), and papers relevant to major hemorrhagic events were identified; results from studies that used a randomized controlled trial (RCT) or a prospective design are presented here. Overall, the identified studies support the current guideline recommendations and indicate that prothrombin complex concentrates have at least similar safety profiles to other treatment options, such as fresh frozen plasma and recombinant activated factor VII. Expert opinion: It is hoped that the results from studies discussed here will inform future guideline updates; however, local clinical practice may also occasionally act as a barrier to adoption of guideline recommendations. There is an urgent need for further RCTs/prospective trials directly comparing PCC and plasma administration in acute bleeding settings.

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

Background

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

Methods

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

Results

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

Conclusion

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

Effectiveness of four-factor prothrombin complex concentrates versus plasma on vitamin K antagonist associated plasma international normalized ratio reversal: a systematic review protocol

REVIEW QUESTION

The question of this review is: what is the effectiveness of Kcentra/Beriplex/Confidex compared to plasma for international normalized ratio (INR) reduction in adult patients (18 years and over) on any vitamin K antagonist therapy?

Utility of the Aspirin and P2Y12 Response Assays to Determine the Effect of Antiplatelet Agents on Platelet Reactivity in Traumatic Brain Injury

BACKGROUND

Premorbid antithrombotic medication may worsen intracranial injury and outcome after traumatic brain injury (TBI). Routine laboratory tests are insufficient to evaluate platelet activity.

OBJECTIVE

To profile the spectrum of platelet inhibition, as measured by aspirin and P2Y12 response unit assays, in a TBI population on antiplatelet therapy.

METHODS

This single-center, prospective cohort study included patients presenting to our institution between November 2010 and January 2015 with a clinical history of TBI. Serum platelet reactivity levels were determined immediately on admission and analyzed using the aspirin and P2Y12 response unit assays; test results were reported as aspirin response units and P2Y12 response units. We report congruence between assay results and clinical history as well as differences in assay results between types of antiplatelet therapy.

RESULTS

A sample of 317 patients was available for analysis, of which 87% had experienced mild TBI, 7% moderate, and 6% severe; the mean age was 71.5 years. The mean aspirin response units in patients with a history of any aspirin use was 456 ± 67 (range, 350-659), with 88% demonstrating therapeutic platelet inhibition. For clopidogrel, the mean P2Y12 response unit was 191 ± 70 (range, 51-351); 77% showed therapeutic response.

CONCLUSION

Rapid measurement of antiplatelet function using the aspirin and P2Y12 response assays indicated as many as one fourth of patients on antiplatelet therapy do not have platelet dysfunction. Further research is required to develop guidelines for the use of these assays to guide platelet transfusion in the setting of TBI.

Prothrombin Complex Concentrates for Bleeding in the Perioperative Setting

Prothrombin complex concentrates (PCCs) contain vitamin K-dependent clotting factors (II, VII, IX, and X) and are marketed as 3 or 4 factor-PCC formulations depending on the concentrations of factor VII. PCCs rapidly restore deficient coagulation factor concentrations to achieve hemostasis, but like with all procoagulants, the effect is balanced against thromboembolic risk. The latter is dependent on both the dose of PCCs and the individual patient prothrombotic predisposition. PCCs are approved by the US Food and Drug Administration for the reversal of vitamin K antagonists in the setting of coagulopathy or bleeding and, therefore, can be administered when urgent surgery is required in patients taking warfarin. However, there is growing experience with the off-label use of PCCs to treat patients with surgical coagulopathic bleeding. Despite their increasing use, there are limited prospective data related to the safety, efficacy, and dosing of PCCs for this indication. PCC administration in the perioperative setting may be tailored to the individual patient based on the laboratory and clinical variables, including point-of-care coagulation testing, to balance hemostatic benefits while minimizing the prothrombotic risk. Importantly, in patients with perioperative bleeding, other considerations should include treating additional sources of coagulopathy such as hypofibrinogenemia, thrombocytopenia, and platelet disorders or surgical sources of bleeding. Thromboembolic risk from excessive PCC dosing may be present well into the postoperative period after hemostasis is achieved owing to the relatively long half-life of prothrombin (factor II, 60-72 hours). The integration of PCCs into comprehensive perioperative coagulation treatment algorithms for refractory bleeding is increasingly reported, but further studies are needed to better evaluate the safe and effective administration of these factor concentrates.

Safety of a Four-factor Prothrombin Complex Concentrate Versus Plasma for Vitamin K Antagonist Reversal: An Integrated Analysis of Two Phase IIIb Clinical Trials

OBJECTIVES

Clinicians often need to rapidly reverse vitamin K antagonists (VKAs) in the setting of major hemorrhage or urgent need for surgery. Little is known about the safety profile of the traditional reversal agent, plasma, or the newly approved agent, four-factor prothrombin complex concentrate (4F-PCC), in a randomized setting. This is an integrated analysis of safety data from two clinical trials that evaluated 4F-PCC versus plasma for the treatment of patients requiring rapid VKA reversal for acute major bleeding or prior to an urgent surgical/invasive procedure.

METHODS

This descriptive analysis comprised adverse event (AE) data from two phase IIIb, randomized, controlled trials. The bleeding and surgical studies were performed across 36 and 33 sites, respectively, in nine countries, with the integrated analysis comprising 388 patients (4F-PCC, n = 191; plasma, n = 197) aged ≥ 18 years, who required VKA reversal due to major bleeding or prior to an urgent surgical/invasive procedure. Patients received either 4F-PCC, containing nonactivated factors II, VII, IX, and X and proteins C and S (Beriplex/Kcentra, CSL Behring) or plasma, both dosed according to baseline international normalized ratio and body weight. Patients were also to receive vitamin K1. AEs and serious AEs (SAEs) were assessed up to days 10 and 45, respectively.

RESULTS

The proportion of patients with AEs (4F-PCC, 115/191 [60.2%]; plasma, 124/197 [62.9%]) and SAEs (4F-PCC, 54/191 [28.3%]; plasma, 49/197 [24.9%]) was similar between groups. The proportion of patients with thromboembolic events was also similar between groups (4F-PCC, 14/191 [7.3%]; plasma, 14/197 [7.1%]). There were 13 (6.8%) deaths in the 4F-PCC group and 13 (6.6%) in the plasma group. Fluid overload events occurred in more patients in the plasma group than the 4F-PCC group (25 [12.7%] and 9 [4.7%], respectively).

CONCLUSIONS

These safety data represent the largest controlled assessment of a 4F-PCC to date. For patients requiring urgent VKA reversal, 4F-PCC had a safety profile similar to that of plasma (AEs, SAEs, thromboembolic events, and deaths), but was associated with fewer fluid overload events.

Brodifacoum Inhalation and its Clinical Manifestations in a 21-Year-Old Caucasian Man

Exposure to brodifacoum, a superwarfarin substance, can lead to severe coagulopathic manifestations. Brodifacoum is a lipophilic, vitamin K antagonist with a long half-life. Clinical manifestations are challenging to diagnose if the patient cannot provide information regarding exposure. Herein, we report the first case in the literature, to our knowledge, of a patient who had intentionally inhaled brodifacoum. We performed coagulation studies such as prothrombin time (PT) and international normalized ratio (INR) to monitor vitamin K dependent coagulation factors in the patient, a 21-year-old Caucasian man. On admission to the hospital, the INR of the patient was 12.9; a computed tomography (CT) angiogram detected a mediastinal hemorrhage. In the absence of 4-factor PCC, the patient received 30 plasma transfusions during a 4-day period due to persistent left pleural effusions, along with vitamin K therapy to normalize his coagulation factors. His high-performance liquid chromatography (HPLC) results on hospital day 3 and day 26 confirmed the presence of brodifacoum in his body. We believe that inhalation led the poison to bypass the initial metabolism process of the liver, resulting in rapid anticoagulation and subsequent bleeding diathesis. Management of brodifacoum poisoning is case dependent on the amount of exposure and INR status. Constant INR monitoring, large dose vitamin K therapy and initial plasma transfusions (in the absence of PCC) were able to prevent severe internal bleeding in the patient.

Perioperative blood conservation strategies for major spine surgery

BACKGROUND

Orthopedic surgery, especially spine and spinal deformity surgery, may be associated with high perioperative blood loss. In order to reduce the risk of excessive blood loss and unnecessary blood transfusions, strategies such as Patient Blood Management including goal-directed coagulation management have been developed.

RECENT FINDINGS

Adverse effects of allogeneic blood transfusions have been shown for most surgical fields including orthopedic surgery. Several efforts have been made to increase the preoperative red blood cell (RBC) mass, to reduce the intraoperative blood loss, and to use restrictive transfusion triggers in order to minimize or avoid RBC transfusions. Measures to reduce intraoperative blood loss include new surgical techniques, use of cell salvage where possible, bedside coagulation management with point-of-care devices, substitution of coagulation factors, antifibrinolytic agents, and desmopressin, induced hypotension, and avoidance of hypothermia.

SUMMARY

Blood conservation in spinal surgery is a multidisciplinary approach and the efficacy of most single measures has been shown. Cost-effectiveness and the benefits of long-term patient outcomes are the subjects of current and future research.

Point of care and factor concentrate-based coagulation algorithms

In the last years it has become evident that the use of blood products should be reduced whenever possible. There is increasing evidence regarding serious adverse events, including higher mortality and morbidity, related to transfusions. The use of point of care (POC) devices integrated in algorithms is one of the important mechanisms to limit blood product exposure. Any type of algorithm, especially the POC-based ones, allows goal-directed transfusions of blood products and even better targeted factor concentrate substitutions. Different types of algorithms in different surgical settings (cardiac surgery, trauma, liver surgery etc.) have been established with growing interest in their use as they offer objective therapy for management and reduction of blood product use. The use of POC devices with evidence-based algorithms is important in the bleeding patient independent of its origin (traumatic vs. surgical). The use of factor concentrates compared to the classical blood products can be cost-saving, beneficial for the patient, and in agreement with the WHO-requested standard of care. The empiric and uncontrolled use of blood products such as fresh frozen plasma, red blood cells, and platelets without POC monitoring should no longer be followed with regard to actual evidence in literature. Furthermore, the use of factor concentrates may provide better outcomes and potential for cost saving.

Comparative analysis of activity of coagulation Factors V and VIII and level of fibrinogen in fresh frozen plasma and frozen plasma

Background:

The aim of this study was to analyse and compare the activity of factor V, VIII and fibrinogen level in fresh frozen plasma and frozen plasma frozen after 8 hrs but within 24 hours after phlebotomy.

Materials and Methods:

Fresh frozen plasma separated from whole blood within 8 hours was compared with plasma separated within 24 hours after phlebotomy in terms of coagulation factors V and VIII and level of fibrinogen by standard methods using semi automated coagulometer sysmex CA50.

Results:

Longer storage of whole blood before processing resulted in significant decrease (18.4%) in activity of factor VIII but the fall in activity of factor V (6.52%) or level of fibrinogen (1.81%) was not significant.

Discussion:

These data suggest that there is good retention of coagulation factors in both types of plasma. Although there is significant fall in activity of factor VIII, but it is an acute phase reactant and raised in most of the diseases so it is suggested that frozen plasma would be an acceptable product for most patients requiring fresh frozen plasma.

Four factor prothrombin complex concentrate (human): review of the pharmacology and clinical application for vitamin K antagonist reversal

Vitamin K antagonists (VKAs) have been used for decades for the treatment and prophylaxis of thromboembolic events. Due to their wide range of therapeutic indications, they are the most prescribed oral anticoagulant worldwide. However, they are associated with bleeding complications due to their narrow therapeutic range, variability in individual dose responses and laboratory monitoring, and overdoses. Despite off-label use of 3-factor prothrombin complex concentrates and recombinant activated factor VII, until recently, vitamin K and plasma were the only recommended therapeutic options for reversing VKAs in the USA. In 2013, a 4-factor prothrombin complex concentrate (4F-PCC) was approved in the USA for VKA reversal in patients with bleeding or requiring emergency surgery and invasive procedure. Recent randomized controlled clinical trials have shown that 4F-PCC (Kcentra™) is non-inferior for hemostatic efficacy and superior for international normalized ratio correction as compared to plasma and has a similar safety profile.

The role of prothrombin complex concentrates in reversal of target specific anticoagulants

Over the past several years a new era for patients requiring anticoagulation has arrived. The approval of new target specific oral anticoagulants offers practitioners several advantages over traditionally used vitamin K antagonist agents including predictable pharmacokinetics, rapid onset of action, comparable efficacy and safety, all without the need for routine monitoring. Despite these benefits, hemorrhagic complicates are inevitable with any anticoagulation treatment. One of the major disadvantages of the new oral anticoagulants is lack of specific antidotes or reversal agents for patients with serious bleeding or need for urgent surgery. As use of the new target specific oral anticoagulants continues to increase, practitioners will need to understand both the pharmacodynamics and pharmacokinetic properties of the agents, as well as, the available literature with use of non-specific therapies to reverse anticoagulation. Four factor prothrombin complex concentrates have been available for several years in Europe, and recently became available in the United States with approval of Kcentra. These products have shown efficacy in reversing anticoagulation from vitamin K antagonists, however their usefulness with the new target specific oral anticoagulants is poorly understood. This article will review the properties of dabigatran, rivaroxaban and apixaban, as well as the limited literature available on the effectiveness of prothrombin complex concentrates in reversal of their anticoagulant effects. Additional studies are needed to more accurately define the role of prothrombin complex concentrates in patients with life threatening bleeding or who require emergent surgery, as current data is both limited and conflicting.

Use of Confidex to control perioperative bleeding in pediatric heart surgery: prospective cohort study

Bleeding during and after cardiac surgery is a major issue in pediatric patients. A prospective cohort study was conducted to evaluate the effect of a commercially available prothrombin complex (Confidex) administered in cardiac surgery after weaning from cardiopulmonary bypass of infants with nonsurgical bleeding. In this study, 14 patients younger than 1 year received a Confidex bolus and were matched with 11 patients of a similar age who did not receive the drug. The preoperative coagulation profile was similar in the two groups. No side effects, including anaphylaxis or thrombotic events, were observed. The numbers of units of packed red blood cells and fresh frozen plasma administered both intra- and postoperatively were similar. The postoperative coagulation examination results and thromboelastographic parameters did not differ significantly between the two groups. However, the Confidex patients bled significantly less than the control subjects during the first 24 postoperative hours. The median volume of drained blood was 0.0 ml/kg h (range 0-1.9 ml/kg h) compared with 1.9 ml/kg h (range 1-3 ml/kg h) (p = 0.009). At least one unit of packed red blood cells in the postoperative phase was required by 2 patients (14 %) in the Confidex group and six patients (54 %) in the control group (odds ratio [OR], 0.13; 95 % confidence interval [CI], 0.02-0.9; p = 0.03). The median duration of mechanical ventilation was 3 days (range 2-4 days) in the Confidex group and 4 days (range 0-8 days) in the control group (p = 0.66). The median stay in the intensive care unit was 6 days (range 5-9 days) in the Confidex group and 7 days (range 4-12 days) in the control group (p = 0.88). The use of Confidex for infants undergoing cardiac surgery was safe and effective. It reduced postoperative bleeding and allowed fewer units of packed red blood cells to be infused in the postoperative phase without major side effects.

Prothrombin complex concentrate

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The December 2013 monograph topics are vortioxetine, mechlorethamine gel, brimonidine tartrate topical gel, obinutuzumab, and miltefosine. The DUE/MUE is on vortioxetine.

Rapid reversal of warfarin-associated hemorrhage in the emergency department by prothrombin complex concentrates

Life-threatening warfarin-associated hemorrhage is common, with a high mortality. In the United States, the most commonly used therapies--fresh frozen plasma and vitamin K--are slow and unpredictable and can result in volume overload. Outside of the United States, prothrombin complex concentrates are often used instead; these pooled plasma products reverse warfarin anticoagulation in minutes rather than hours. This article reviews the literature relating to warfarin reversal with fresh frozen plasma, prothrombin complex concentrates, and recombinant factor VIIa and provides elements for a management protocol based on this literature.

Current State of Knowledge on Oral Anticoagulant Reversal Using Procoagulant Factors

OBJECTIVE:

To discuss current trends and challenges in the use of procoagulants for treating bleeding caused by use of oral anticoagulants.

DATA SOURCES:

Literature searches of PubMed (MEDLINE), Google, and Medscape were conducted in February 2013. There were no date limitations. Search terms included anticoagulation agents, anticoagulation reversal, anticoagulation reversal agents, apixaban, clinical studies, dabigatran, 3-factor PCCs, 4-factor PCCs, FEIBA, fresh frozen plasma, human studies, pharmacology, prescribing information, rFVIIa, rivaroxaban, vitamin K, and warfarin.

DATA SYNTHESIS:

Warfarin has been the mainstay for the treatment and prevention of primary and secondary thrombosis in patients with cardiovascular disorders such as atrial fibrillation, deep vein thrombosis, pulmonary embolism, and stroke. Three oral anticoagulants have recently become available in the US: a direct thrombin inhibitor, dabigatran etexilate, and 2 direct factor Xa inhibitors, rivaroxaban and apixaban. Reversal strategies for anticoagulant-associated bleeding are well established for warfarin; however, strategies to stop bleeding in a patient who has taken one of the newer anticoagulants are less clear. In the US, agents available for oral anticoagulant reversal include activated prothrombin complex concentrate (APCC), 3-factor PCCs, and recombinant activated factor VII (rFVIIa). Few studies have evaluated the 3-factor PCCs, and current evidence for APCC and rFVIIa as reversal agents for dabigatran and rivaroxaban is based primarily on laboratory or animal studies, or on small studies in healthy humans and case reports.

CONCLUSIONS:

Patients contemplating using the new oral anticoagulants should be informed about specific clinical situations that could pose a bleeding risk such as the need for emergency surgery because no reliable antidote is available to stop the bleeding, which could prove fatal.

Intracerebral hemorrhage in patients receiving oral anticoagulation therapy

Intracerebral hemorrhage (ICH) in patients with oral anticoagulation therapy is an increasingly prevalent problem in large part due to the aging population and the increased use of anticoagulants for patients at high risk of thrombosis. Warfarin has been virtually the only outpatient anticoagulant choice until fairly recently. The development of subcutaneously injected heparinoids, and more recently, of direct thrombin inhibitors, has made the treatment and prognostication of ICH in anticoagulated patients more difficult. In this review, we will review the current state of diagnosis, prognostication, and treatment for patients with this often-devastating type of bleeding. We will focus on warfarin therapy, because the preponderance of evidence comes from studies of warfarin treatment. Where there is evidence, we will contrast warfarin with some of the newer treatment modalities. We review the evidence of the 4 major reversal agents for warfarin, vitamin K, prothrombin complex concentrates, activated factor VII, and fresh frozen plasma as well as rational treatment choices. We offer possible treatments for the newer anticoagulants based on the limited evidence available. Finally, we review recommendations from the major societies and studies that support early and aggressive therapies in intensive care units with dedicated neurological specialists.

Long-term safety and efficacy of a pasteurized nanofiltrated prothrombin complex concentrate (Beriplex P/N): a pharmacovigilance study

Background

The rapid reversal of the effects of vitamin K antagonists is often required in cases of emergency surgery and life-threatening bleeding, or during bleeding associated with high morbidity and mortality such as intracranial haemorrhage. Increasingly, four-factor prothrombin complex concentrates (PCCs) containing high and well-balanced concentrations of vitamin K-dependent coagulation factors are recommended for emergency oral anticoagulation reversal. Both the safety and efficacy of such products are currently in focus, and their administration is now expanding into the critical care setting for the treatment of life-threatening bleeding and coagulopathy resulting either perioperatively or in cases of acute trauma.

Methods

After 15 yr of clinical use, findings of a pharmacovigilance report (February 1996–March 2012) relating to the four-factor PCC Beriplex P/N (CSL Behring, Marburg, Germany) were analysed and are presented here. Furthermore, a review of the literature with regard to the efficacy and safety of four-factor PCCs was performed.

Results

Since receiving marketing authorization (February 21, 1996), ∼647 250 standard applications of Beriplex P/N have taken place. During this time, 21 thromboembolic events judged to be possibly related to Beriplex P/N administration have been reported, while no incidences of viral transmission or heparin-induced thrombocytopenia were documented. The low risk of thromboembolic events reported during the observation period (one in ∼31 000) is in line with the incidence observed with other four-factor PCCs.

Conclusions

In general, four-factor PCCs have proven to be well tolerated and highly effective in the rapid reversal of vitamin K antagonists.

Contemporary Anticoagulation Reversal Focus on Direct Thrombin Inhibitors and Factor Xa Inhibitors

Several oral direct thrombin inhibitors (DTIs) and factor Xa (FXa) inhibitors have recent Food and Drug Administration approval or are under investigation in late-stage clinical trials for the prevention and treatment of thromboembolic events. Rapid reversal of anticoagulation is typically recommended in patients with severe or life-threatening bleeding and in patients requiring surgery or invasive procedures. However, no antidote exists for DTIs or FXa inhibitors though replacement of coagulation factors using clotting factor concentrates is routinely considered in some clinical scenarios. Clotting factor concentrates available in the United States include prothrombin complex concentrate, activated prothrombin complex concentrate, and recombinant factor VII, activated. Coagulation tests to confirm adequate reversal of anticoagulation should be considered and commonly include activated partial thromboplastin time and thrombin time (TT) for DTIs, and chromogenic FXa assay and TT for FXa inhibitors. Monitoring of coagulation tests should continue for 1 to 2 days after achievement of hemostasis, since the duration of the clotting factor concentrate may be shorter than the oral anticoagulant, especially in patients with organ dysfunction. Utilization of decision-support tools and use of standardized reversal protocols are recommended to prevent errors in prescribing and dispensing for clotting factor concentrates.

Prothrombin complex concentrates in emergency bleeding disorders

The use of prothrombin complex concentrates (PCCs), a heterogeneous combination of coagulation factors and counterbalancing inhibitor components, has broadened in recent years beyond single-factor replacement in conditions such as hemophilia B, to encompass emergency reversal of anticoagulation secondary to oral vitamin K antagonists, ie, warfarin therapy. PCCs also have been studied in other bleeding disorders, such as surgery-related and trauma-related bleeding. This review provides an updated examination of the differences among PCC formulations, their potential role in the management of bleeding disorders, and the primary safety issues affecting their use. Am. J. Hematol. 2012. © 2012 Wiley Periodicals, Inc.

Reversal of dabigatran anticoagulation by prothrombin complex concentrate (Beriplex P/N) in a rabbit model

BACKGROUND

One limitation of the direct thrombin inhibitor dabigatran is the lack of specific antidotes that allow acute bleeding events to be managed or urgent interventional procedures performed. Prothrombin complex concentrates (PCCs) have served as a standard treatment for the reversal of coumarin anticoagulation.

OBJECTIVES

This study was designed to determine in an animal model whether a PCC (Beriplex P/N) can effectively reverse the effects of dabigatran. An additional objective was to evaluate markers of dabigatran-associated bleeding diathesis.

METHODS

Anesthetized rabbits were treated with 0.4 mg kg(-1) dabigatran followed by PCC doses of 20, 35 or 50 IU kg(-1) or placebo. After a standardized kidney incision, volume of blood loss and time to hemostasis were determined.

RESULTS

From an initial mean of 29 mL, blood loss progressively declined by 5.44 mL with a 95% confidence interval (CI) of 2.21-8.67 mL per 10 IU kg(-1) increment in PCC dose (P = 0.002). At a PCC dose of 50 IU kg(-1) blood loss was fully normalized. Increasing PCC doses shortened the median time to hemostasis from 20.0 to 5.7 min (P < 0.001). The rate of hemostasis was nearly trebled with each 10 IU kg(-1) increment in PCC dose (rate ratio, 2.89; CI, 1.64-5.09).

CONCLUSIONS

In this animal study, PCC showed potential as an agent for reversing the effects of dabigatran. Further investigation is warranted.

Experience with prothrombin complex for the emergent reversal of anticoagulation in rural geriatric trauma patients

BACKGROUND

Therapeutic anticoagulation in the geriatric trauma population is increasingly common. Fresh frozen plasma, while the criterion standard for correction, has limited availability and associated transfusion risks. We examined our use of prothrombin complex concentrate for immediate reversal of therapeutically anticoagulated geriatric trauma patients.

METHODS

This was a 1-year, retrospective review of 25 geriatric trauma patients who received either fresh frozen plasma alone or prothrombin complex concentrate and met the inclusion criteria of age >55 years, current warfarin use, and an admission international normalized ratio of >1.5. Fifteen patients received prothrombin complex concentrate and 10 patients received fresh frozen plasma alone. We examined demographics, laboratory values, and blood product use.

RESULTS

The mean ages were similar (77 vs 80 years). Patients had similar mean Injury Severity Score (19.1 vs 19.2). Survivor duration of hospital stay (7.7 vs 9.5; P = .37) and duration of stay in the intensive care unit (4.4 vs 7.1; P = .25) trended positively in the prothrombin complex concentrate group. The prothrombin complex concentrate group received fewer units of fresh frozen plasma (1.6 [range, 0-6] vs 2.7 [range, 2-4]; P = .05), with a greater decrease in international normalized ratio (51% vs 43%; P = .05). Six patients (40%) in the prothrombin complex concentrate group avoided fresh frozen plasma transfusion altogether.

CONCLUSION

Prothrombin complex may be used safely and effectively to reverse emergently anticoagulation in geriatric trauma patients.

Reversal of warfarin-induced hemorrhage in the emergency department

Warfarin, an oral vitamin K antagonist, is used to prevent arterial and venous thromboembolism in patients suffering from a multitude of diseases. In 2004, 31 million warfarin prescriptions were dispensed in the United States. Warfarin inhibits the activation of the vitamin K-dependent clotting factors (Factors II, VII, IX, and X) and regulatory proteins (proteins C, S, and Z). It is one of the leading drugs implicated in emergency room visits for adverse drug reactions. Annually the frequency of bleeding complications associated with overanticoagulation is 15% to 20%, with fatal bleeds measuring as high as 1% to 3%. The most effective method of warfarin reversal involves the use of Four Factor Prothrombin Complex Concentrate (PCC), which is widely used throughout Europe but is unavailable in the United States. The current therapies available to emergency room physicians in the United States are fresh frozen plasma, recombinant Factor VIIa (rFVIIa), Factor Eight Inhibitory Bypassing Activity, or Three Factor PCC concomitantly administered with vitamin K. We review the advantages and disadvantages of these therapies and recommend Three Factor PCC with small doses of rFVIIa and with vitamin K in life-threatening situations if Four Factor PCC is unavailable.

Experience on Using Prothrombin Complex Concentrate in Urgent Warfarin Reversal

We evaluated the effectiveness and safety of prothrombin complex concentrate (PCC) in urgent warfarin reversal in Iran. This is a nonrandomized, pre–post intervention study. Thirty-seven high-risk patients with prolonged international normalized ratio ([INR] >8) or with bleeding symptoms were enrolled in this study. Prothrombin complex concentrate was infused with a dose of 22.4 ± 11.2 IU/kg. The INR was measured 30 minutes postinfusion. Mean age of the participants was 63.9 ± 14.5 (22-89 years). After 30 minutes of PCC injection, INR reversed to <3.5 in 31 patients (84%) in whom 12 patients achieved INR 1.5 to 2.5, and 19 patients achieved INR 2.5 to 3.5. Bleeding symptoms were subsided during 0.5 hour after PCC infusion in patients with hemorrhagic symptoms. Not any adverse reaction was observed in patients during 3-month follow-up. Our experience in use of single injection of PCC in high-risk patients with prolonged INR or with bleeding symptoms was successful without any complication.

Massive sublingual hematoma secondary to anticoagulant therapy complicated by a traumatic denture: a case report

Introduction

Sublingual hematoma secondary to excessive anticoagulation is a rare but potentially fatal condition, and few cases have been documented in the literature.

Case presentation

We report the case of a 73-year-old Caucasian woman who attended our Accident and Emergency department with massive sublingual hematoma causing superior displacement of the tongue. The condition was found to be the result of an elevated international normalized ratio, further complicated by a traumatic mandibular denture.

Conclusions

In summary, we recommend the immediate reversal of anticoagulation therapy on admission of patients with severe sublingual hematoma. We further advise surgical decompression/drainage if required and to continue meticulous monitoring. In all cases of early recognition of sublingual hematoma, prompt medical treatment and continuous clinical monitoring is essential, and may prevent the need for a surgical airway procedure.

An observational, prospective, two-cohort comparison of a fixed versus variable dosing strategy of prothrombin complex concentrate to counteract vitamin K antagonists in 240 bleeding emergencies

BACKGROUND

Despite years of experience with vitamin K antagonist-associated bleeding events, there is still no evidence to help identify the optimal treatment with prothrombin complex concentrates. Variable dosing and fixed dose strategies are being used. In this observational prospective two-cohort study, we aimed to assess the non-inferiority of a low fixed PCC dose (1,040 IU Factor IX) compared to the registered variable dosing regimen based on baseline International Normalized Rate, bodyweight, and target International Normalized Rate, to counteract vitamin K antagonists in a bleeding emergency in a daily clinical practice setting.

DESIGN AND METHODS

Non-inferiority of the fixed prothrombin complex concentrate dose was hypothesized with a margin of 4%. Main end points were proportion of patients reaching the target International Normalized Rate (< 2.0) after prothrombin complex concentrate treatment, and successful clinical outcome.

RESULTS

Target International Normalized Rate was reached in 92% of the fixed dose patients (n=101) versus 95% of variable dose patients (n=139) resulting in a risk difference of -2.99% (90% CI: - 8.6 to 2.7) (non-inferiority not confirmed). Clinical outcome was successful in 96% and 88% of fixed versus variable dose, respectively, with a risk difference of 8.3% (90% CI: 2.7-13.9; non-inferiority confirmed).

CONCLUSIONS

Although a lower fixed prothrombin complex concentrate dose was associated with successful clinical outcome, fewer patients reached the target International Normalized Rate.