Potential role for rFVIIa in transfusion medicine

Early stage clinical trials for the treatment of hemophilia A

INTRODUCTION

Hemophilia A is a severe bleeding disorder affecting about 1 in 5,000 males. The gold standard for prophylaxis and treatment of acute bleeding has been factor (F) VIII concentrate. A multitude of treatment modalities are now available and under clinical investigation.

AREAS COVERED

This review discusses ongoing/recently completed early-phase clinical trials registered on ClinicalTrials.gov in patients with hemophilia A through April 2022. These new pipeline therapies are focused on addressing the safety and efficacy of new factor-related products, non-factor related products, and gene therapy options for hemophilia.

EXPERT OPINION

Current standard of care effectively prevents and treats acute bleeding and has significantly improved the quality of life in hemophilia. The biggest challenges in the improvement of care are treatment-related burden and the burden of cost in developing countries. New drugs under development are likely to enter practice by the end of this decade and address many of the unmet needs particularly of those with severe disease. Data is limited in unique populations (e.g. congenital/inherited FVIII inhibitors, non-severe hemophilia A, women/girls with hemophilia and children) which are important areas for future research; additional clinical trials and long-term outcome data are necessary prior to incorporating these new therapies in our treatment arsenal.

Use of recombinant activated factor VII for the treatment of perioperative bleeding in noncardiac surgery patients without hemophilia: A systematic review and meta-analysis of randomized controlled trials

PURPOSE

To evaluate the efficacy and safety of perioperative use of recombinant activated factor VII (rFVIIa) in noncardiac patients.

MATERIALS AND METHODS

We searched electronic databases for randomized controlled trials (RCTs) that involved the use of rFVIIa through December 13, 2019 in noncardiac patients without hemophilia. Two investigators extracted the related data and assessed the quality of the included trials.

RESULTS

Eleven RCTs examining 993 perioperative patients were ultimately included. The use of rFVIIa did not decrease all-cause mortality (RR:0.90; 95% CI:0.50,1.64; I² = 0.0%; P = 0.738), shorten the length of ICU (SMD:-0.15; 95% CI:-0.47,0.17; I² = 0.0%; P = 0.346) or hospital (SMD:0.42; 95% CI:-0.05,0.89; I² = 0.0%; P = 0.078) stay, or increase incidence of the thromboembolic events (RR:1.30; 95% CI:0.70,2.41; I² = 0.0%; P = 0.403) among perioperative patients. However, individual RCT analyses showed that the use of rFVIIa could reduce the volume of blood loss (including prostatic cancer, severe acute pancreatitis (SAP), and spinal disease) and the transfusion of RBCs (including prostatic cancer, SAP, and spinal disease) and FFP (SAP) in a subset of perioperative patients. Publication bias was not present.

CONCLUSIONS

For perioperative hemorrhagic patients, rFVIIa-based hemostatic therapy showed no effect on mortality, ICU or hospital LOS, or the rate of thromboembolic events, although it appears to decrease blood loss and reduce the need for blood product transfusion in a subset of patients.

Comparison of Neonatal and Adult Fibrin Clot Properties between Porcine and Human Plasma

BACKGROUND

Recent studies suggest that adult-specific treatment options for fibrinogen replacement during bleeding may be less effective in neonates. This is likely due to structural and functional differences found in the fibrin network between adults and neonates. In this investigation, the authors performed a comparative laboratory-based study between immature and adult human and porcine plasma samples in order to determine if piglets are an appropriate animal model of neonatal coagulopathy.

METHODS

Adult and neonatal human and porcine plasma samples were collected from the Children's Hospital of Atlanta and North Carolina State University College of Veterinary Medicine, respectively. Clots were formed for analysis and fibrinogen concentration was quantified. Structure was examined through confocal microscopy and cryogenic scanning electron microscopy. Function was assessed through atomic force microscopy nanoindentation and clotting and fibrinolysis assays. Lastly, novel hemostatic therapies were applied to neonatal porcine samples to simulate treatment.

RESULTS

All sample groups had similar plasma fibrinogen concentrations. Neonatal porcine and human plasma clots were less branched with lower fiber densities than the dense and highly branched networks seen in adult human and porcine clots. Neonatal porcine and human clots had faster degradation rates and lower clot stiffness values than adult clots (stiffness [mmHg] mean ± SD: neonatal human, 12.15 ± 1.35 mmHg vs. adult human, 32.25 ± 7.13 mmHg; P = 0.016; neonatal pig, 10.5 ± 8.25 mmHg vs. adult pigs, 32.55 ± 7.20 mmHg; P = 0.015). The addition of hemostatic therapies to neonatal porcine samples enhanced clot formation.

CONCLUSIONS

The authors identified similar age-related patterns in structure, mechanical, and degradation properties between adults and neonates in porcine and human samples. These findings suggest that piglets are an appropriate preclinical model of neonatal coagulopathy. The authors also show the feasibility of in vitro model application through analysis of novel hemostatic therapies as applied to dilute neonatal porcine plasma.

Recombinant activated factor VII is associated with postoperative thromboembolic adverse events in bleeding after coronary surgery

OBJECTIVES

To evaluate the impact of recombinant activated factor VII (rFVIIa) administration on thromboembolic adverse events (TAEs) in coronary artery bypass grafting (CABG) surgery patients showing postoperative bleeding.

METHODS

From January 2004 to May 2015, 180 CABG surgery patients with postoperative bleeding were included in the study. All patients were managed conservatively and 81 (45%) also received rFVIIa.

RESULTS

Ten patients developed new TAEs (5.6%), 15 (8.3%) were re-explored, 4 (2.2%) had postoperative dialysis and 6 (3.3%) died by day 30 postoperation. Among those with TAEs, 7 experienced cerebrovascular accidents, 2 had myocardial infarction and 1 had pulmonary embolism. A multivariable regression model confirmed rFVIIa as the only independent factor associated with the development of TAEs (odds ratio 6.19, 95% confidence interval 1.197-31.996; P = 0.0296). Fifteen (8.3%) patients were re-explored for bleeding according to our management protocol. No variables to predict the need for re-exploration were identified by the regression model. Chest tube output was statistically significantly lower in patients who received rFVIIa from 3 h [1.9 (Q1-Q3 1.7-2.1) ml/kg/h vs 3.2 (Q1-Q3 3-3.4) ml/kg/h, P = 0.000] through to 12 h after admission [0.6 (Q1-Q3 0.5-0.6) ml/kg/h vs 0.7 (Q1-Q3 0.6-0.9) ml/kg/h, P = 0.000].

CONCLUSIONS

rFVIIa for the treatment of post-CABG bleeding resulted in increased incidence of TAEs in spite of rapid control of bleeding. Hence, rFVIIa should only be used for selected patients and with extreme caution.

Use of Recombinant Activated Factor VII after Axillofemoral Bypass Grafting

Recombinant activated factor VII (rFVIIa) is a powerful prohaemostatic agent that theoretically predisposes to thrombosis after peripheral vascular surgery. We report the use of rFVIIa to reduce bleeding in a patient after axillofemoral bypass grafting for ruptured aorto-iliac pseudoaneurysm. Despite the increased risk of thrombosis, the patient made an uneventful recovery with preserved graft patency. The favourable result suggests that rFVIIa should be considered even in vascular surgical patients, if the risks of continued bleeding outweigh those of thrombosis. Better risk estimation is only possible if reports of rFVIIa use in vascular patients continue to appear and through controlled trials.

Bloodless Intensive Care: A Case Series and Review of Jehovah's Witnesses in ICU

The objective of this study was to assess the outcome of Jehovah's Witness (JW) patients admitted to a major Australasian ICU and to review the literature regarding the management of critically ill Jehovah's Witness patients.

All Jehovah's Witness patients admitted to the ICU between January 1999 and September 2003 were identified from a prospective database. Their ICU mortality, APACHE II scores, APACHE II risk of death and ICU length of stay were compared to the general ICU population. Twenty-one (0.24%) out of 8869 patients (excluding re-admissions) admitted to the ICU over this period were Jehovah's Witness patients. Their mean APACHE II score was 14.1 (±7.0), the mean APACHE II risk of death was 21.2% (±16.6), and the mean nadir haemoglobin (Hb) was 80.2 g/l (±36.4). Four out of 21 Jehovah's Witness patients died in ICU compared to 782 out of 8848 non- Jehovah's Witness patients (19.0% vs 8.8%, P=0.10, chi square). The median ICU length of stay in both groups was two days (P=0.64, Wilcoxon rank sum). The lowest Hb recorded in a survivor was 23 g/l.

Jehovah's Witness patients appear to be an uncommon patient population in a major Australasian ICU but are not over-represented when compared with their prevalence in the community. Despite similar severity of illness scores and predicted mortality to those in the general ICU population, there was a trend towards higher mortality in Jehovah's Witness patients.

Change of coagulation after NovoSeven® use for bleeding during cardiac surgery

Objectives Recombinant activated factor VII has been used for the treatment of hemophilia, factor VII deficiency, and Glanzmann's thrombasthenia. Off-label uses have recently been increasing, and there are reports that recombinant activated factor VII is effective for the treatment of excessive bleeding during or after cardiovascular surgery. We retrospectively reviewed the effectiveness of recombinant activated factor VII and its influence on the coagulation system as a treatment for uncontrollable bleeding during cardiovascular surgery. Methods Between April 2009 and May 2015, recombinant activated factor VII was used to treat uncontrollable bleeding during cardiovascular surgery in 17 patients at our hospital. The indications for recombinant activated factor VII administration were critical uncontrollable bleeding during surgery and normal platelet and fibrinogen levels. Results Blood loss significantly decreased in every case after recombinant activated factor VII administration ( p < 0.05). No adverse thromboembolic events were encountered. The prothrombin time-international normalized ratio, activated partial thromboplastin time, fibrin degradation product and D-dimer levels decreased significantly after recombinant activated factor VII administration. One day later, all blood coagulation test values were almost within the normal ranges. Conclusions Recombinant activated factor VII has a strong hemostatic action, but it is necessary to exclude surgical bleeding to exhibit the hemostatic effect. Administration that does not comply with the indications for recombinant activated factor VII may lead to serious complications such as thromboembolism. In properly selected patients, recombinant activated factor VII is an effective agent for the treatment of uncontrollable bleeding during cardiovascular surgery.

Liver trauma

Management of blunt or penetrating injury to the liver remains a significant challenge to trauma surgeons. Liver injury remains common in both blunt and penetrating trauma of the abdomen. Unstable patients require immediate laparotomy. Selective patients can be managed without surgery and with careful monitoring. There has been a recent resurgence in the role of temporary packing in the management of liver trauma. Other commonly used techniques are resectional debribement and suture ligation of bleeding vessels. Complications include haemorrhage, bile leak and sepsis. Mortality is mainly due to damage to major hepatic blood vessels or other associated non-hepatic injuries. With improved understanding of the major causes of death from hepatic injury, improved resuscitation and intensive care, mortality has fallen below 10%.

A rare combination: congenital factor VII deficiency with Chiari malformation

Congenital factor (VII) deficiency is a rare bleeding disorder. We present a patient with congenital FVII deficiency and congenital hydrocephalus who underwent a ventriculoperitoneal shunt operation and needed no prophylaxis after the procedure.

NovoSeven (recombinant factor VIIa) for the treatment of bleeding episodes and perioperative management in patients with Glanzmann's thrombasthenia

Glanzmann's thrombasthenia is a rare inherited autosomal recessive bleeding disorder caused by qualitative or quantitative defects of the platelet membrane glycoprotein IIb/IIIa. The ensuing lack of platelet aggregation is frequently associated with mucocutaneous bleeding that may be variable in both frequency and intensity, ranging from minimal bruising to severe and life-threatening hemorrhages. A number of treatment modalities have been proposed to manage the bleeding episodes, which include local measures, antifibrinolytic agents, platelet transfusions and recombinant activated factor VII. The role of this bypassing hemostatic agent for treatment or prevention of bleeding episodes in Glanzmann's thrombasthenia patients is critically analyzed in this review.

Implementation of an off-label recombinant factor VIIa protocol for patients with critical bleeding at an academic medical center

To describe the development of a pharmacy driven off-label recombinant factor seven (rFVIIa) protocol by a multi-disciplinary team for critical bleeding. A multi-disciplinary team made up of members from several critical care and surgical departments within the hospital were formed and charged with developing a standardized approach to how rFVIIa would be used for critical bleeding in an academic medical center. Groups represented on the multi-disciplinary team included clinical pharmacy, emergency medicine, pulmonary, hematology, cardiothoracic surgery, trauma, neurosurgery, and vascular surgery physicians. A pharmacist driven off-label rFVIIa protocol was developed and implemented for the use in those patients with critical bleeding. The protocol was based on the available literature and local expert opinion. Through the use of this protocol a significantly smaller average dose of rFVIIa is now being used when compared to those patients treated prior to the new protocol (47.5 vs. 62.2 mcg/kg, p = 0.036) while all-cause mortality was not significantly altered (35 vs. 48.8%, p = 0.057). An effective and safe pharmacy driven protocol was implemented by a multi-disciplinary team for rFVIIa as seen by providing a significantly lower average dose of rFVIIa while not sacrificing for overall patient mortality.

The Australian and New Zealand Haemostasis Registry: ten years of data on off-licence use of recombinant activated factor VII

BACKGROUND

Recombinant activated factor VII (rFVIIa) has been widely used as an off-licence pan-haemostatic agent in patients with critical bleeding. However, outside the trauma setting, there is relatively little high quality evidence on the risks and benefits of this agent. The Haemostasis Registry was established to investigate the extent of use, dosing, safety and outcomes of patients after off-licence rFVIIa treatment of critical bleeding.

MATERIALS AND METHODS

The Registry recruited non-haemophiliac patients treated with rFVIIa from 2000-2009 (inclusive) in Australia and New Zealand. Detailed information was gathered on patients' demographics, context of bleeding, rFVIIa administration, laboratory results, blood component and other therapies, and outcomes. Outcome measures included subjectively assessed effect of rFVIIa on bleeding (response), adverse events (thromboembolic and other) and 28-day mortality.

RESULTS

The registry included 3,446 cases in 3,322 patients (median [IQR] age 56 [33-70] years, 65% (n=2,147) male). Clinical indications included cardiac surgery (45%), other surgery (18%), trauma (13%), medical bleeding (6%), liver disease (6%), and obstetric haemorrhage (5%). The median [IQR] dose was 91 [72-103] μg/kg and 77% received a single dose. Reduction or cessation of bleeding was reported in 74% and 28-day survival was 71% but outcomes varied depending on clinical context. pH strongly correlated with outcome measures; 81% of patients with pH <7.1 died. Approximately 11% of patients had thromboembolic adverse events. In multivariate analysis, pH prior to administration and bleeding context were independently associated with reported response to rFVIIa and 28-day mortality.

DISCUSSION

The Haemostasis Registry is the largest dataset of its kind and provides observational data on the off-licence use of rFVIIa over a 10-year period. It has been an invaluable resource for rigorously tracking adverse events and helping to inform clinical practice.

Recombinant Activated Factor VII in Patients at High Risk of Bleeding

Currently, recombinant activated factor VII (rFVIIa) (NovoSeven) is indicated for the treatment of spontaneous and surgical bleeding in congenital haemophilia A and B patients with inhibitors to factors VIII (FVIII) and IX (FIX) >5 Bethesda units (BU) worldwide, and in patients with acquired haemophilia, congenital FVII deficiency and Glanzmann's thrombasthenia in Europe. Until April 2003, almost three-quarters of a milion doses of rFVIIa have been administered proving its efficacy and excellent safety record. According to results from initial clinical trials and a large number of case reports, the rFVIIa may be effective not only in treating haemophilia patients but also in treatment of bleeding in patients on oral anticoagulation or heparin, patients with liver diseases, von Willebrand disease (vWD), thrombocytopenia, various platelet defects, congenital or acquired deficiency of FVII, and in subjects without any pre-existing coagulopathy with diffuse life-threatening bleeding triggered by surgery or trauma. This review will briefly summarize rFVIIa mode of action in haemostasis, the current clinical experience with rFVIIa and focus on the alternative use of rFVIIa in patients at the high risk of bleeding in both spontaneous cases and clinical trials reports.

Prediction score for effective bleeding control using recombinant activated factor VII in perioperative nonhemophilic patients

BACKGROUND

Although there has been growing evidence from off-label use of recombinant activated factor VII (rFVIIa) in surgical bleeding, there is limited information on prediction scores.

METHODS

A retrospective study was conducted from 2004 to 2009. The primary outcome was efficacy of bleeding control. Multivariate logistic regression was performed to develop a new prediction score for success of rFVIIa.

RESULTS

A total of 320 bleeding episodes from 243 nonhemophilic patients who underwent surgery were analyzed. Effective bleeding control was demonstrated in 153 patients. The overall in-hospital mortality rate was 40%. Multivariate analysis identified 4 independent predictors for effective bleeding control: timing of rFVIIa administration, intraoperative blood loss, postoperative international normalization ratio values, and total units of platelets transfused. A rFVIIa success prediction score was developed.

CONCLUSIONS

The use of this new prediction score may support decision making by identifying patients with a high probability of obtaining effective bleeding control from rFVIIa therapy.

Timely 'off-label' use of recombinant activated factor VII (NovoSeven(®)) can help in avoiding hysterectomy in intractable obstetric bleeding complicated with disseminated intravascular coagulation: A case report and review of the literature

Massive intra-operative bleeding is not an infrequent occurrence in obstetrics. Worldwide obstetric bleeding remains a major cause of morbidity and mortality. Conventional management of this bleeding consists of resuscitation with fluids, blood, surgical maneuvers, and embolisation of feeding blood vessels. But in most of cases, these measures appear to be ineffective in controlling bleeding. Recently, the 'off-label' use of the recombinant activated factor VII (rFVIIa) concentrate has emerged as promising treatment for such bleeding when conventional measures fail. We came across a similar scenario in which a young lady was admitted with per-vaginal bleeding due to abruptio placentae. In spite of usual surgical and medical interventions, she continued to bleed. rFVIIa was administered as a desperate measure to avoid hysterectomy and the bleeding could be stopped. She recovered successfully without any complication. Thus, the timely use of rFVIIa, hence, can be used to save life and fertility in cases of intractable obstetric bleeding.

Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia

BACKGROUND

Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies and for prophylaxis and treatment of patients with congenital factor VII deficiency. It is also used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means. This is the third version of the 2007 Cochrane review on the use of recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia, and has been updated to incorporate recent trial data.

OBJECTIVES

To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding or prophylactically to prevent (excessive) bleeding in patients without haemophilia.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and other medical databases up to 23 March 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population (except haemophilia). Outcomes were mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed potentially relevant studies for inclusion, extracted data and examined risk of bias. We considered prophylactic and therapeutic rFVIIa studies separately.

MAIN RESULTS

Twenty-nine RCTs were included: 28 were placebo-controlled, double-blind RCTs and one compared different doses of rFVIIa. In the 'Risk of bias' assessment, most studies were found to have some threats to validity although therapeutic RCTs were found to be less prone to bias than prophylactic RCTs.Sixteen trials involving 1361 participants examined the prophylactic use of rFVIIa; 729 received rFVIIa. There was no evidence of mortality benefit (risk ratio (RR) 1.04; 95% confidence interval (CI) 0.55 to 1.97). There was decreased blood loss (mean difference (MD) -297 mL; 95% CI -416 to -178) and decreased red cell transfusion requirements (MD -261 mL; 95% CI -367 to -154) with rFVIIa treatment; however, these values were likely overestimated due to the inability to incorporate data from trials (four RCTs in the outcome of blood loss and three RCTs in the outcome of transfusion requirements) showing no difference of rFVIIa treatment compared to placebo. There was a trend in favour of rFVIIa in the number of participants transfused (RR 0.85; 95% CI 0.72 to 1.01). However, there was a trend against rFVIIa with respect to thromboembolic adverse events (RR 1.35; 95% CI 0.82 to 2.25).Thirteen trials involving 2929 participants examined the therapeutic use of rFVIIa; 1878 received rFVIIa. There were no outcomes where any observed advantage or disadvantage of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality (RR 0.91; 95% CI 0.78 to 1.06). However, there was a trend against rFVIIa for increased thromboembolic adverse events (RR 1.14; 95% CI 0.89 to 1.47).When all trials were pooled together to examine the risk of thromboembolic events, a significant increase in total arterial events was observed (RR 1.45; 95% CI 1.02 to 2.05).

AUTHORS' CONCLUSIONS

The effectiveness of rFVIIa as a more general haemostatic drug, either prophylactically or therapeutically, remains unproven. The results indicate increased risk of arterial events in patients receiving rFVIIa. The use of rFVIIa outside its current licensed indications should be restricted to clinical trials.

Aortic valve replacement in a Jehovah's Witness: a case of multi-disciplinary clinical management for bloodless surgery

An 81-year-old female Jehovah's Witness (JW) patient with severe aortic stenosis required aortic valve replacement (AVR). However, the patient's religious beliefs precluded the use of primary blood components. Since the definitive treatment of AVR required bloodless open heart surgery, careful peri-operative plans were set forth by a multi-disciplinary team involving the cardiothoracic surgeon, haematologist and anaesthetist. The patient went on to successfully recover postoperatively. This case highlights: 1) The importance of carefully navigating through the most recent clinical and ethical protocol involved in the surgical management of JW's. 2) The importance of preparing individually tailored pre, intra and postoperative plans that are delivered through a multi-disciplinary clinical team to ensure the best and safest possible outcomes.

Is EPCR a multi-ligand receptor? Pros and cons

In the last decade, the endothelial cell protein C/activated protein C receptor (EPCR) has received considerable attention. The role initially attributed to EPCR, i.e. the enhancement of protein C (PC) activation by the thrombin-thrombomodulin complex on the surface of the large vessels, although important, did not go beyond the haemostasis scenario. However, the discovery of the cytoprotective, anti-inflammatory and anti-apoptotic features of the activated PC (APC) and the required involvement of EPCR for APC to exert such actions did place the receptor in a privileged position in the crosstalk between coagulation and inflammation. The last five years have shown that PC/APC are not the only molecules able to interact with EPCR. Factor VII/VIIa (FVII/VIIa) and factor Xa (FXa), two other serine proteases that play a central role in haemostasis and are also involved in signalling processes influencing wound healing, tissue remodelling, inflammation or metastasis, have been reported to bind to EPCR. These observations have paved the way for an exploration of unsuspected new roles for the receptor. This review aims to offer a new image of EPCR in the light of its extended panel of ligands. A brief update of what is known about the APC-evoked EPCR-dependent cell signalling mechanisms is provided, but special care has been taken to assemble all the information available about the interaction of EPCR with FVII/VIIa and FXa.

Redistribution and hemostatic action of recombinant activated factor VII associated with platelets

Clinical evidence accumulated from hemophilic patients during prophylaxis with recombinant activated factor VII (rFVIIa) suggests that the duration of the hemostatic action of rFVIIa exceeds its predicted plasma half-life. Mechanisms involved in this outcome have not been elucidated. We have investigated in vitro the redistribution of rFVIIa in platelets from healthy donors, patients with FVII deficiency, and one patient with Bernard-Soulier syndrome. Platelet-rich plasma was exposed to rFVIIa (3 to 60 μg/mL). Flow cytometry, immunocytochemistry, and coagulation tests were applied to detect and quantify rFVIIa. The hemostatic effect of rFVIIa associated to platelets was evaluated using perfusion models. Our studies revealed a dose-dependent association of rFVIIa to the platelet cytoplasm with redistribution into the open canalicular system, and α granules. Mechanisms implicated in the internalization are multiple, involve GPIb and GPIV, and require phospholipids and cytoskeletal assembly. After platelet activation with thrombin, platelets exposed rFVIIa on their membrane. Perfusion studies revealed that the presence of 30% of platelets containing FVIIa improved platelet aggregate formation and enhanced fibrin generation (P < 0.01 versus control). Our results indicate that, at therapeutic concentrations, rFVIIa can be internalized into platelets, where it is protected from physiological clearance mechanisms and can still promote hemostatic activity. Redistribution of rFVIIa into platelets may explain the prolonged prophylactic effectiveness of rFVIIa in hemophilia.

The first case of postpartum acquired hemophilia A in Korea

Acquired hemophilia A (AHA) is a rare coagulopathy caused by autoantibodies to coagulation factor VIII (FVIII). Most patients with AHA have been previously healthy; however, a variety of morbidities have been associated with the condition including pregnancy. A 40-yr-old woman visited our institution with extensive hematoma on the right hip area. Her medical history revealed no personal or familial history of bleeding diathesis. Her coagulation tests showed markedly prolonged aPTT (117 sec), markedly decreased level of FVIII activity (0.4%) and high-titer FVIII inhibitor (77 BU). Collectively, she was diagnosed as having postpartum AHA and was treated with bypassing agents and corticosteroids. Her aPTT was normalized on the 174 th postpartum day and FVIII inhibitor showed negative conversion on the 224 th postpartum day. This is the first case of postpartum AHA with high-titer FVIII inhibitor in Korea. Timely diagnosis and management can reduce morbidity and mortality of this potentially life-threatening condition.

Recombinant activated factor VII usage in life threatening hemorrhage: a pediatric experience

OBJECTIVE

To determine the safety and efficacy of off label usage of Recombinant activated factor VII (rFVIIa) in children with severe bleeding in non-hemophiliac children with diverse etiologies like leukemia, post hematopoietic stem cell transplantation, dengue shock syndrome and Glanzmann thrombasthenia.

METHOD

Medical records of 16 non-hemophiliac children with 20 bleeding episodes where rFVIIa was administered only after failure of standard measures to control bleeding were retrospectively reviewed and data collected regarding patient demographics, diagnosis and location of bleeding. Blood counts, coagulation and other lab parameters, both pre and post rFVIIa, were also noted. Severity of bleeding was assessed using a scoring system used previously by Nevo S et al. A record of usage of the amount of blood components (red blood cells, platelets, fresh frozen plasma, and cryoprecipitate) 24 h pre and post rFVIIa was also made. The dose of rFVIIa and any adverse side effects were recorded.

RESULTS

Bleeding sites were gastrointestinal (13/20), pulmonary hemorrhage (6/20) and intracranial hemorrhage (1/20). Thrombocytopenia (platelet count <50,000/cumm) was present in 50% episodes and five had refractory low platelets. Usage of packed red cells and platelets was significantly less after usage of rFVIIa (p value 0.001 and 0.006, respectively). Mean dosage of rFVIIa was 77 μgm/kg/dose (range 60 to 90 μgm/kg/dose). The bleeding stopped completely in 11(55%), decreased to minimal in 2 (10%), reduced but transfusions needed in 4 (20%) and did not stop in 3 (15%) episodes. Five patients (31%) did not survive the bleeding episode. None of the patients developed thrombosis.

CONCLUSIONS

rFVIIa appears to be safe and effective in controlling life-threatening bleed in non-hemophiliac children.

Update and new developments in the management of the exsanguinating patient

Definitive management of the exsanguinating patient continues to challenge providers in multiple specialties. Significant hemorrhage may be encountered in a variety of patient care circumstances. Over the past two decades, the vast majority of data and evidence regarding transfusion in the exsanguinating patient has been based upon the trauma literature, and a large amount of recent research has investigated this subject area. In addition to the care of trauma patients, the data which have emerged can also be extrapolated to the treatment of nontrauma patients undergoing transfusion for major hemorrhage. The concept of massive transfusion is an evolving paradigm, and numerous investigations have challenged old principles while creating new controversies. The current review will examine the latest developments in the management of patients with profound hemorrhage. The challenges of dealing with the "lethal triad" will be discussed, as will the various aspects of damage control and hemostatic resuscitation. The latest literature and controversy regarding massive transfusions and massive transfusion protocols will be elucidated with inclusion of data from recent military experiences. Finally, adjuncts including the most recent advances in hemorrhage control, identification of early predictors for massive transfusion, and utilization of pharmacologic and complementary factor agent therapy will be discussed.

Reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery

At present, individual techniques, including intraoperative acute normovolemic hemodilution, use of tranexamic acid, use of intrathecal morphine, proper positioning, and modification of operative techniques, seem most promising for reducing perioperative blood loss and allogeneic blood transfusion in patients undergoing major spine surgery. Other techniques including preoperative autologous predonation; mandatory discontinuation of use of antiplatelet agents; intraoperative and postoperative red-blood-cell salvage; use of aprotinin, epsilon-aminocaproic acid, recombinant factor VIIa, or desmopressin; induced hypotension; avoidance of hypothermia; and minimally invasive operative techniques require additional studies to either establish their effectiveness or address safety considerations.

Acute volume resuscitation following obstetric hemorrhage

Hemorrhage remains a leading cause of pregnancy-related morbidity and mortality. A rapid collaborative approach to management of the woman experiencing excessive blood loss is required to optimize outcomes. Successful treatment of the hemorrhaging pregnant woman is dependent on early recognition of bleeding and clinical manifestations of shock, treatment of the underlying cause of the hemorrhage, and simultaneous restoration of adequate circulating volume as well as blood component therapy. Early communication with providers, identified triggers for changes in patient condition, and drills/simulations with the multidisciplinary healthcare team are critical strategies for improving response and outcomes.

Monitoring rFVIIa 90 μg kg⁻¹ dosing in haemophiliacs: comparing laboratory response using various whole blood assays over 6 h

Recombinant FVIIa is a haemostatic agent administered to patients with severe FVIII or FIX deficiency with inhibitors. Although rFVIIa is effective at stopping bleeding, a reliable assay to monitor its effect is lacking. To characterize the pharmacokinetics and global coagulation effects of rFVIIa for 6 h following a IV dose of 90 μg kg⁻¹. Ten non-bleeding subjects with severe FVIII or FIX deficiency were infused with a single-dose of rFVIIa 90 μg k⁻¹ body weight and blood was collected before and at 0.5, 1, 2, 4 and 6 h postdose. Global haemostasis was characterized throughout the study utilizing whole blood analyses (Hemodyne HAS, TEG, ROTEM). The clearance and half-life of factor FVII:C was estimated as 39.0 ± 8.8 mL h⁻¹ kg⁻¹ and 2.1 ± 0.2 h respectively. There was good inter-assay agreement with respect to clot initiation parameters (R, CT and FOT) and these parameters all fell to a mean of approximately 9 min following rFVIIa dosing. The platelet contractile force (PCF) and clot elastic modulus (CEM) were positively correlated to FVII:C (P < 0.0001), and these parameters were dynamic throughout the 6-h period. The MA and MCF did not correlate to FVII:C nor did they significantly change during the study. Prothrombin F1 + 2 significantly increased following rFVIIa dosing (P < 0.001), but remained steady throughout the study. There was no change in D-dimer concentrations over time. The FOT, R and CT characterized clot initiation following rFVIIa dosing. The PCF and CEM were correlated to FVII:C and characterized the dynamics of platelet function and clot strength over the rFVIIa dosing interval. The clinical significance of these findings needs additional study.

Novel approaches to the treatment of intracerebral haemorrhage

Intracerebral haemorrhage is the most devastating subtype of stroke. It affects approximately two million patients worldwide every year and is a major cause of morbidity and mortality. After decades of research, we still face the fact that there is no evidence-based treatment strategy for this disease. However, research has contributed to a better understanding of the pathophysiology of intracerebral haemorrhage and also to the identification of new treatment targets. Several novel aspects of treatment of spontaneous intracerebral haemorrhage are reviewed in the present article.

Recombinant factor VIIa for the prevention and treatment of bleeding in patients without haemophilia

BACKGROUND

Recombinant factor VIIa (rFVIIa) is licensed for use in patients with haemophilia and inhibitory allo-antibodies. It is also increasingly being used for off-license indications to prevent bleeding in operations where blood loss is likely to be high, and/or to stop bleeding that is proving difficult to control by other means.

OBJECTIVES

To assess the effectiveness of rFVIIa when used therapeutically to control active bleeding, or prophylactically to prevent (excessive) bleeding in patients without haemophilia.

SEARCH STRATEGY

We searched the Cochrane Injuries Group Specialised Register, CENTRAL, MEDLINE, EMBASE and other specialised databases up to 25 February 2009.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing rFVIIa with placebo, or one dose of rFVIIa with another, in any patient population (except haemophilia). Outcomes were mortality, blood loss or control of bleeding, red cell transfusion requirements, number of patients transfused and thromboembolic adverse events.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed potentially relevant studies for inclusion, extracted data and examined risk of bias. We considered prophylactic and therapeutic rFVIIa studies separately.

MAIN RESULTS

Twenty-five RCTs were included: 24 were placebo-controlled double-blind RCTs and one compared different doses of rFVIIa.Fourteen trials involving 1137 participants examined the prophylactic use of rFVIIa; 713 received rFVIIa. There was no evidence of mortality benefit (RR 1.06; 95% CI 0.50 to 2.24). There was decreased blood loss (WMD -272 mL; 95% CI -399 to -146) and decreased red cell transfusion requirements (WMD -243 mL; 95% CI -393 to -92) with rFVIIa treatment; however these values were likely overestimated due to the inability to incorporate data from trials showing no difference of rFVIIa treatment compared to placebo. There was a trend in favour of rFVIIa in the number of participants transfused (RR 0.91; 95% CI 0.82 to 1.02). But there was a trend against rFVIIa with respect to thromboembolic adverse events (RR 1.32; 95% CI 0.84 to 2.06).Eleven trials involving 2366 participants examined the therapeutic use of rFVIIa; 1507 received rFVIIa. There were no outcomes where any observed advantage, or disadvantage, of rFVIIa over placebo could not have been observed by chance alone. There was a trend in favour of rFVIIa for reducing mortality (RR 0.89; 95% CI 0.77 to 1.03). However, there was a trend against rFVIIa for increased thromboembolic adverse events (RR 1.21; 95% CI 0.93 to 1.58).

AUTHORS' CONCLUSIONS

The effectiveness of rFVIIa as a more general haemostatic drug, either prophylactically or therapeutically, remains unproven. The use of rFVIIa outside its current licensed indications should be restricted to clinical trials.

Recombinant factor VIIa affects anastomotic patency of vascular grafts in a rabbit model

OBJECTIVE

Recombinant factor VIIa can decrease postoperative bleeding after cardiac surgery. However, the potential for recombinant factor VIIa to cause early vascular graft occlusion at the site of new vascular anastomoses has not been fully explored. We hypothesized that recombinant factor VIIa would cause a dose-dependent reduction in vascular graft patency in rabbits.

METHODS

Reversed end-to-end interpositional vein grafts were sutured into the carotid artery of heparinized rabbits, and then recombinant factor VIIa (300 μg/kg, 90 μg/kg, or 20 μg/kg intravenously) or placebo was administered (n = 16/group). Graft patency was assessed at 24 hours using a vascular ultrasound probe. Factor VII activity levels were measured using a prothrombin time-based assay. In different rabbits, the patency of venous end-to-side anastomoses and simple carotid arterial repairs was assessed (recombinant factor VIIa, 300 μg/kg vs placebo, n = 8/group). Data were analyzed using Fisher's exact test, t tests, or analysis of variance.

RESULTS

Physiologic variables (activated clotting time, hemoglobin, pH, Pao(2)) and vessel diameter were not different between groups. Vein graft patency was reduced (93.8%, 81.2%, 13.8%, and 6.3%) as factor VII activity levels increased (1.8 ± 0.4, 4.4 ± 2.1, 11.8 ± 4.7, and 23.6 ± 16.9 U/mL, respectively) with increasing doses of recombinant factor VIIa administered (0, 20, 90, and 300 μg/kg, respectively, P < .05). Patency in the arterial repairs and end-to-side venous grafts was also reduced in recombinant factor VIIa-treated rabbits (P < .05 for both).

CONCLUSIONS

This study suggests that recombinant factor VIIa is associated with a dose-dependent increase in fresh vascular graft occlusion. Higher doses of recombinant factor VIIa may be associated with increased thrombotic outcomes.

Principles of hemostasis in children: models and maturation

Hemostasis is an active process regulating the formation and dissolution of fibrin clot to preserve vascular integrity. The different phases of hemostasis are coordinated so that effective clotting occurs only at the site of vascular injury while maintaining blood flow in other parts of the circulation. Procoagulant processes culminate in thrombin generation and fibrin clot formation to protect the vasculature against uncontrolled bleeding after injury. Conversely, anticoagulant processes limit clot extension to unaffected portions of the vasculature. Lastly, fibrinolysis is responsible for clot dissolution once tissue repair and regeneration permit the return of normal blood flow. A precise and delicate interplay exists among these processes to ensure normal hemostasis. The hemostatic system is incompletely developed at birth and matures throughout infancy. Both full-term and preterm neonates are born with low levels of most procoagulant proteins including all the contact activation factors and vitamin K-dependent factors. Similarly, levels of the major anticoagulant proteins are low at birth. Although often characterized as 'immature', the neonatal hemostatic system is nevertheless functionally balanced with no tendency toward coagulopathy or thrombosis. In this article, we will review the current models of hemostasis and the maturation of the hemostatic system. Our goal is to help clinicians gain a better understanding of the actions of procoagulant agents and of the disruptive effects of serious systemic illnesses on the precarious hemostatic balance of infants.

Use of Recombinant Activated Factor VII for Intractable Bleeding in Patients Without Hemophilia: A Developing Country Tertiary Care Center’s Experience

Although the use of recombinant activated factor VII (rFVIIa) to control intractable bleeding in nonhemophiliac patients is expanding, several issues pertinent to its potential thrombotic complications and effect on patient mortality are still of concern. We herein describe our experience at a developing country tertiary care center over a period of 4 years. A total of 49 patients were identified of whom 28.6% belong to the pediatric age group. The most common bleeding settings were intracerebral hemorrhage, abdominal aortic surgery, general surgery, and disseminated intravascular coagulopathy. All patients achieved cessation or significant reduction in bleeding. Only 1 patient had a documented postuse thrombotic complication. Of the whole group, 12 patients (24.4%) eventually died with only 1 death having a possible association to rFVIIa use. There was a statistically significant reduction in the need for blood product transfusion after the use of rFVIIa. The use of rFVIIa was in accordance with the hospital’s algorithm (identifying salvageable patients, preconditioning, blood product replacement, and dosing) in 30 (61.2%) patients. We conclude that rFVIIa should continue to be considered in nonhemophiliac patients failing to respond to conventional measures of bleeding control. However, this off-label use should be coupled with strict adherence to the treatment algorithms, which remains essential in developing countries with limited health care resources.

Recombinant activated factor VII in liver patients: a retrospective cohort study from Australia and New Zealand

Recombinant factor VIIa (rFVIIa) is used in the treatment of life-threatening haemorrhage that is refractory to conventional treatment. The evidence supporting this practice in patients with liver disease is very limited. It has been used as a salvage therapy in end-stage liver disease (ESLD), in orthotopic liver transplant (OLT), other surgery, and upper gastrointestinal bleeding (UGIB) subpopulations. It has also been used prior to procedures in patients with ESLD. Data were collected by the Australia and New Zealand Haemostasis Registry (ANZHR) to perform a retrospective cohort study on the different subgroups of liver patients. This included 115 cases of use of rFVIIa in liver patients from 20 hospitals. A retrospective cohort study on the different subgroups of liver patients was performed. Main outcome measures were reduction or cessation of bleeding and 28-day mortality. Variables previously shown to predict response to bleeding after administration of rFVIIa were examined to determine whether correlations exist. Salvage therapy with rFVIIa was associated with reduction or cessation in bleeding in 24 of 36 OLT patients, 24 of 36 UGIB patients and 15 of 26 of other surgery patients. Clinical response to rFVIIa in OLT patients and other surgery patients was associated with a significantly lower mortality compared to nonresponders (P = 0.003 and 0.022, respectively). There was no relationship between mortality and bleeding response in patients with UGIB. Variables including acidosis, hypothermia, hypofibrinogenaemia, thrombocytopenia and Model of End-Stage Liver Disease (MELD) score were not associated with clinical response to rFVIIa. Five cases of use prior to procedures are described. Recombinant FVIIa is used as rescue therapy in surgical patients with ESLD and refractory haemorrhage in Australia and New Zealand. Traditional haemostasis variables were not associated with clinical response to rFVIIa in this cohort. Response to rFVIIa is associated with decreased mortality in ESLD patients undergoing OLT and other surgery, but not in UGIB.

Blood product replacement for postpartum hemorrhage

Hemorrhage requiring blood transfusion is a common occurrence in obstetrics. This article reviews each step in the transfusion process, including laboratory preparation of blood, indications for various blood components, complications of blood transfusion, massive transfusion, and alternatives to homologous blood. Current thinking regarding transfusion-related acute lung injury, transfusion-related immunomodulation, early use of plasma for massive transfusion, and the use of adjuvant agents such as activated recombinant factor VII are also discussed.

Prediction and management of bleeding in cardiac surgery

Excessive bleeding after cardiac surgery can result in increased morbidity and mortality related to transfusion- and hypoperfusion-related injuries to critical organ systems. Our objective was to review mechanisms that result in bleeding after cardiac surgery as well as current and emerging interventions to reduce bleeding and transfusion. We discovered that of point-of-care (POC) tests of hemostatic function can facilitate the optimal management of excessive bleeding and reduce transfusion by facilitating administration of specific pharmacologic or transfusion-based therapy and by allowing physicians to better differentiate between microvascular bleeding and surgical bleeding. Emerging interventions like recombinant FVIIa have the potential to reduce bleeding and transfusion-related sequelae and may be life-saving; however, randomized, controlled trials are needed to confirm safety before they can be used as either first-line therapies for bleeding or bleeding prophylaxis. In conclusion, careful investigation of the role of new interventions is essential as the ability to reduce use of blood products, to decrease operative time and/or re-exploration rates has important implications for overall patient safety and health care costs.

[Reversal of acenocoumarol anticoagulation with activated factor VII in massive hemorrhage following rupture of a splenic artery pseudoaneurysm]

A 66-year-old man with a metallic valve and under treatment with acenocoumarol developed hypovolemic shock after rupture of a splenic artery pseudoaneurysm. We managed to reverse anticoagulation within 60 minutes by administering 20 mg of vitamin K and 4.8 mg of activated recombinant factor VII. No thromboembolic adverse events were observed. We discuss the pharmacologic effects of coumarin derivatives and their antagonists, as well as the use of activated factor VII in the reversal of anticoagulation by these drugs.

Diagnosis and surgical management of spontaneous hepatic rupture associated with HELLP syndrome

Spontaneous hepatic rupture with hemoperitoneum is an uncommon but devastating complication of hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. Although the syndrome has been considered a variant of preeclampsia/eclampsia, its pathogenesis is not completely understood. Hepatic rupture increases the perinatal and maternal morbidity and mortality. This report describes 3 cases of extensive spontaneous hepatic rupture in pregnant women with HELLP syndrome. Early diagnosis and adequate tertiary management of this rare but life-threatening condition reduce the high maternal and newborn mortality.

Emergency reversal of antithrombotic treatment

The most important adverse effect of antithrombotic treatment is the occurrence of bleeding. In case of serious or even life-threatening bleeding in a patient who uses anticoagulant agents or when a patient on anticoagulants needs to undergo an urgent invasive procedure, anticoagulant treatment can be reversed by various specific strategies. Heparin and heparin derivatives can be counteracted by protamine sulphate, whereas the anticoagulant effect of vitamin K antagonists may be neutralized by administration of vitamin K or prothrombin complex concentrates. The anti-hemostatic effect of aspirin and other anti-platelet strategies can be corrected by the administration of platelet concentrate or desmopressin, if needed. Recently, a new generation of anticoagulants with a greater specificity towards activated coagulation factors has been introduced and most of these agents are presently being evaluated in clinical studies. The new generation anticoagulants include specific inhibitors of factor IIa, factor Xa (including pentasaccharides) and agents that interfere with tissue factor activity. A limitation of this new class of anticoagulants may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs, although in some cases the administration of recombinant factor VIIa may be an option.

Can a Subset of Intracerebral Hemorrhage Patients Benefit From Hemostatic Therapy With Recombinant Activated Factor VII?

Background and Purpose— In the Factor Seven for Acute Hemorrhagic Stroke (FAST) trial, 80 μg/kg of recombinant activated factor VII (rFVIIa) significantly reduced intracerebral hemorrhage (ICH) expansion when given within 4 hours of onset. However, in contrast to an earlier Phase 2b study, rFVIIa did not improve survival or functional outcome. In this exploratory analysis, we hypothesized that earlier treatment and exclusion of patients with a poor prognosis at baseline might enhance the benefit of rFVIIa treatment.

Methods— Using the FAST data set, the impact of rFVIIa (80 μg/kg) on poor outcome at 3 months (modified Rankin Score of 5 or 6) was systematically evaluated within subgroups using clinically meaningful cut points in onset-to-treatment time, age, and baseline ICH and intraventricular hemorrhage volume. The effect of treatment on outcome was analyzed using logistic regression, and ICH volume was analyzed with linear mixed models.

Results— A subgroup (n=160, 19% of the FAST population) was identified comprising patients ≤70 years with baseline ICH volume <60 mL, intraventricular hemorrhage volume <5 mL, and time from onset-to-treatment ≤2.5 hours. The adjusted ORs for poor outcome with rFVIIa treatment was 0.28 (95% CI, 0.08 to 1.06), whereas the reduction in ICH growth was almost doubled (7.3±3.2 versus 3.8±1.5 mL, P =0.02). The improved effect was confirmed in an analysis of similar Phase 2 patients.

Conclusions— A prospective trial would be needed to determine whether younger patients with ICH without extensive bleeding at baseline can benefit from 80 μg/kg of rFVIIa given within 2.5 hours of symptom onset.