Recombinant activated factor VII for the treatment of life-threatening haemorrhage

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.

Local and Systemic Hemostatics as an Adjunct to Control Bleeding in Trauma

Although surgical and angiointervention techniques remain the cornerstone for the management of severe bleeding after trauma, adjunct therapeutic strategies such as local or systemic hemostatic agents can play an important role. This article reviews the role and efficacy of the available hemostatic agents.

Prolonged prothrombin time after recombinant activated factor VII therapy in critically bleeding trauma patients is associated with adverse outcomes

BACKGROUND

In trauma patients with significant hemorrhage, it is hypothesized that failure to normalize prothrombin time (PT) after recombinant activated factor VII (rFVIIa) treatment predicts poor clinical outcomes and potentially indicates a need for additional therapeutic interventions.

METHODS

To assess the value of PT to predict outcomes after rFVIIa or placebo therapy, we performed a post hoc analysis of data from 169 severely injured, critically bleeding trauma patients who had 1-hour postdose PT measurements from two randomized clinical trials. Baseline characteristics and outcome parameters were compared between subjects with 1-hour postdose PT >or=18 seconds and PT <18 seconds.

RESULTS

In rFVIIa-treated subjects, prolonged postdose PT values >or=18 seconds were associated with significantly higher 24-hour mortality (60% vs. 3%; p < 0.001) and 30-day mortality, increased incidence of massive transfusion, and fewer intensive care unit-free days compared with postdose PT values <18 seconds. Recombinant rFVIIa-treated subjects with postdose PT >or=18 seconds had significantly lower baseline hemoglobin levels, fibrinogen levels, and platelet counts than subjects with postdose PT values <18 seconds even though they received similar amounts of blood products before rFVIIa dosing. Placebo-treated subjects with postdose PT >or=18 seconds had significantly increased incidence of massive transfusion, significantly decreased intensive care unit-free days, and significantly lower levels of fibrinogen and platelets at baseline compared with subjects with postdose PT values <18 seconds.

CONCLUSIONS

The presence of prolonged PT after rFVIIa or placebo therapy was associated with poor clinical outcomes. Because subjects with postdosing PT >or=18 seconds had low levels of hemoglobin, fibrinogen, and platelets, this group may benefit from additional blood component therapy.

Recombinant Activated Factor VII (rFVIIa) in the Management of Major Obstetric Haemorrhage: A Case Series and a Proposed Guideline for Use

Major obstetric haemorrhage remains a significant cause of maternal morbidity and mortality. Previous case reports suggest the potential benefit of recombinant activated factor VII (rFVIIa: NovoSeven^R) as a haemostatic agent. We performed a retrospective review of the use of rVIIa in major obstetric haemorrhage in the Northern Region between July 2004 and February 2007. Fifteen women received rFVIIa. The median patient age was 34 years. Major haemorrhage occurred antepartum (5 patients), intrapartum (1), and postpartum (9). All women received an initial dose of 90 mcg/kg rFVIIa and one received 2 further doses. Bleeding stopped or decreased in 12 patients (80%). Additional measures included antifibrinolytic and uterotonic agents, Rusch balloon insertion, uterine curettage/packing, and vessel embolisation. Eight patients required hysterectomy. All women survived to discharge from hospital. No adverse events, including thrombosis, were recorded. This study provides further support for the safety and efficacy of rFVIIa as adjunct therapy in major obstetric haemorrhage.

Abnormal coagulation tests are associated with progression of traumatic intracranial hemorrhage

BACKGROUND

Intracranial hemorrhage (ICH) is common in traumatic brain injury (TBI) and a major determinant of death and disability. ICH commonly increases in size and coagulopathy has been implicated in such progression. We investigated the association between coagulopathy diagnosed by routine laboratory tests and ICH progression.

METHODS

Subgroup post hoc analysis from a randomized controlled trial including adult patients with blunt severe TBI (Glasgow Coma Scale score <or=8) and repeat computerized tomography scans in 48 hours. Coagulopathy was defined as international normalized ratio >or=1.3, activated partial thromboplastin time >or=35, or platelet count (PLT) <or=100 x 10/L any time in the first 24 hours. Progression was any size increase or new ICH. TBI-associated coagulopathy was investigated measuring soluble tissue factor (TF) and d-dimer.

RESULTS

The ICH progressed in 37 of 72 patients (51%), in 80% if any abnormal laboratory test (coagulopathic patients) versus 36% in noncoagulopathic (p = 0.0004). Abnormal international normalized ratio (odds ratio [OR] = 4.09; 95% confidence interval [CI] = 1.29-12.95; p = 0.017), PLT (OR = 12.59; 95% CI = 1.52-108.57; p = 0.019), head Abbreviated Injury Scale (AIS) (OR = 1.82; 95% CI = 1.15-2.88; p = 0.011) were significantly associated with progression (univariate analysis). In a multiple logistic regression, only head AIS (OR = 1.81; 95% CI 1.10-2.98; p = 0.0198) and PLT (OR = 11.8; 95% CI = 1.38-101.23; p = 0.024) correlated with progression. All patients with abnormal partial thromboplastin time experienced progression. ICH progression carried a 5-fold higher odds of death; 32% with progression died versus 8.6% without. Age, head AIS, Injury Severity Score, and d-dimer were also associated with mortality. Tissue factor was not associated with progression or mortality.

CONCLUSION

This study demonstrates an association between coagulopathy, diagnosed by routine laboratorial tests in the first 24 hours, with ICH progression; and ICH progression with mortality in patients with severe TBI. The causal relationship between coagulopathy and ICH progression will require further studies.

Use of recombinant factor VIIa in the treatment of massive retroperitoneal bleeding due to severe necrotizing pancreatitis

Background. Recently, a growing number of case reports and case series have suggested that the use of recombinant activated factor VII (rFVIIa) may be effective in treatment of patients with non-hemophilic acquired coagulopathy not responding to conventional treatment such as major surgery, major trauma, sepsis, necrotizing pancreatitis and bleeding due to cerebral arteriovenous malformations. Case report. We presented a septic patient with massive, lifethreatening bleeding caused by retroperitoneal necrosis, due to severe acute necrotizing pancreatitis. As conservative treatment (blood, plasma, cryoprecipitates and platelet transfusions) failed to induce cessation of bleeding, the patient was urgently operated on. In spite of usual procedures of surgical hemostasis (ligation, suture, thermocauterisation, fibrin glue, temporary tamponade), hemorrhage could not be stopped. The patient manifested the signs of hypothermia and metabolic acidosis and, therefore, the decision was made to use recombinant activated factor VII (Novo Seven?). The application of rFVIIa resulted in significant discontinuation of hemorrhage, restoration to normal blood count as well as other relevant coagulation parameters. Conclusion. Although application of rFVIIa is still in the initial clinical phase, and the experience is based mainly on uncontrolled series as well as on individual observations, it seems that this drug can be promising, potent and attractive adjunctive prohemostatic agent. This drug may play a beneficial role in the treatment of serious and unresponsive, 'nonsurgical', life-threatening bleeding due to severe acute necrotizing pancreatitis.

Current Evidence Based Guidelines for Factor VIIa Use in Trauma: The Good, the Bad, and the Ugly

Recombinant factor VII (rFVIIa) has arisen as an option for the control of life-threatening traumatic bleeding unresponsive to other means. The timing of administration, dosage, mortality, units of blood transfusion saved, risk of thrombotic events, and risk/benefits ratio are presently poorly defined. A Medline search from 1995 through March 2008 was conducted. All English language articles containing the terms “trauma” and “factor VII” or its variants were retrieved. Letters to the editor, animal studies, and general reviews were excluded. A total of 19 articles met inclusion criteria. These articles were then reviewed and stratified into three classes of evidence according to the quality assessment instrument developed by the Brain and Trauma Foundation. Levels of recommendation were developed. A total of 118 articles were identified. Only one Class I study was identified. This study demonstrated that three doses of rFVIIa given in blunt traumatic hemorrhage yielded a significant reduction of 2.6 of red blood cells used. These findings were not statistically significant for penetrating trauma patients. There was no reduction in mortality and no increase in thromboembolic events. Four Class II studies were identified; three showed a significant decrease of blood product usage and one demonstrated significant reductions in 24-hour and 30 day death from hemorrhage in patients receiving rFVIIa. The remaining 14 studies were Class III reviews of databases, registries, case series, and case reports. No identified study specifically addressed the cost/benefit analysis of rFVIIa usage in trauma hemorrhage. Utility of rFVIIa in trauma-associated hemorrhage remains controversial. There is Level I supporting the use of rFVIIa for blunt trauma patients only. There is no Class I evidence supporting decreased mortality or differences in thromboembolic events. Minimal effective dosing regimens and cost/benefit analyses have not yet been examined.

Successful use of recombinant activated factor VII for postoperative associated haemorrhage: a case report

Background

Coagulopathy is a major contributing factor to bleeding related mortality even after achieving adequate surgical control of the haemorrhage in trauma and surgical patients.

Case presentation

A 65 years old Greek man was admitted in our ICU with critical haemorrhage following renal biopsy. Despite surgical exploration the patient continued to bleed resulting in a vicious cycle of transfusion, coagulopathy and re-bleeding. After all standard management options were exhausted, the patient was given rFVIIa (total dose 4,8 mg). Clinical improvement was noted without adverse thrombotic complications. One month later the same patient was operated on for a suspected retroperitoneal infected collection that it was assumed to be the cause of persistent pyrexia. After abdominal washout, he suffered haemorrhagic shock with postoperative coagulopathy. Standard transfusion therapy was again unsuccessful. The patient was given rFVIIa again resulting in an immediate reduction in coagulopathic haemorrhage accompanied by a significant improvement in laboratory measurements and reduction in blood products requirements.

Conclusion

Published clinical experiences for the use of rFVIIa in trauma patients are limited to small series and case reports. However, in trauma patients, administration of rFVIIa appears to be effective in addition to prompt surgical intervention as an adjunctive haemostatic measure to control life threatening bleeding in appropriately selected patients.

Low-dose recombinant factor VIIa for trauma patients with coagulopathy

INTRODUCTION

Coagulopathy in injured patients is common and is generally treated with fresh frozen plasma (FFP). Response can be variable, thus complete correction may take hours and require large volumes of fluids. High-dose recombinant factor VIIa (FVIIa, Novoseven, Novo Nordisk, Bagsvaerd, Denmark) has been used off-label to treat severe coagulopathy following trauma. Expense has limited use. Recently, we began administering low dose FVIIa (1.2mg) to patients with mild to moderate coagulopathy after trauma, hypothetising that it would be effective and safe.

PATIENTS AND METHODS

We retrospectively reviewed consecutive patients who received a low dose of 1.2mg of FVIIa over a 2-year period. Factor VIIa is administered after approval by a gatekeeper at the discretion of the treating physician. Demographics, injury and laboratory data were abstracted as were indications for use, source of coagulopathy, effectiveness, and complications. A two-tailed paired t-test was used to determine significant changes in coagulation parameters and blood product utilisation.

RESULTS

Eighty-one patients received 84 low doses of FVIIa. The mean age of the patients was 51 (+/-22) with a mean ISS of 29 (+/-11). Seventy-three per cent were male and 67% had a traumatic brain injury (TBI) as their primary injury. The aetiology of the coagulopathy in the study population included; TBI (40%), warfarin use (22%), and cirrhosis (13%). Mean prothrombin time (PT) fell from 17.0 s (+/-3.2) to 10.6s (+/-1.4) (p<0.0001). All patients had a good clinical response with no bleeding complications. Utilisation of packed red blood cells and fresh frozen plasma were significantly less in the 24h after FVIIa administration as compared to the 24h prior. Subsequent thromboembolic events were observed in 12 of the 81 patients (15%) and included; cerebrovascular accident (CVA) (6), mesenteric thrombosis (2), myocardial infarction (MI) (1), pulmonary embolism/deep venous thrombosis (PE/DVT) (2), and atrial thrombus (1). Only four of these events were thought to be related to the FVIIa administration, with two of the four contributing to a lethal outcome.

CONCLUSIONS

Low dose FVIIa rapidly and effectively treats mild to moderate coagulopathy following injury. This low dose (1.2mg) FVIIa is the smallest available unit dose. It costs approximately the same as 8 units of plasma and may be cost-effective in patients who require high volume factor administration. Low dose FVIIa may be effective in coagulopathic trauma patients who are not in shock but require rapid normalisation of clotting function.

A benefit-risk review of systemic haemostatic agents: part 1: in major surgery

Systemic haemostatic agents play an important role in the management of blood loss during major surgery where significant blood loss is likely and their use has increased in recent times as a consequence of demand for blood products outstripping supply and the risks associated with transfusions. Their main application is as prophylaxis to reduce bleeding in major surgery, including cardiac and orthopaedic surgery and orthotopic liver transplantation. Aprotinin has been the predominant agent used in this setting; of the other antifibrinolytic agents that have been studied, tranexamic acid is the most effective and epsilon-aminocaproic acid may also have a role. Eptacog alfa (recombinant factor VIIa) has also shown promise. Tranexamic acid, epsilon-aminocaproic acid and eptacog alfa are generally well tolerated; however, when considering the methods to reduce or prevent blood loss intra- and postoperatively, the benefits of these agents need to be weighed against the risk of adverse events. Recently, concerns have been raised about the safety of aprotinin after an association between increased renal dysfunction and mortality was shown in retrospective observational studies and an increase in all-cause mortality with aprotinin relative to tranexamic acid or epsilon-aminocaproic acid was seen after a pre-planned periodic analysis of the large BART (Blood conservation using Antifibrinolytics in a Randomized Trial) study. The latter finding resulted in the trial being halted, and aprotinin has subsequently been withdrawn from the market pending detailed analysis of efficacy and safety results from the study. Part 1 of this benefit-risk review examines the efficacy and adverse effect profiles of systemic haemostatic agents commonly used in surgery, and provides individual benefit-risk profiles that may assist clinicians in selecting appropriate pharmacological therapy in this setting.

Treatment of Diffuse Pulmonary Hemorrhage with Factor VIIa

Blunt thoracic trauma resulting in lung contusion with severe diffuse pulmonary hemorrhage and massive hemoptysis is rare and has a poor prognosis. Treatment options are limited. We report a case of the successful use of recombinant activated factor VII (NovoSeven™) in the treatment of life-threatening diffuse pulmonary hemorrhage secondary to an isolated blunt force thoracic injury without relevant traumatic coagulopathy.

In vitro effect of activated recombinant factor VII (rFVIIa) on coagulation properties of human blood at hypothermic temperatures

BACKGROUND

Recombinant activated factor VII (rFVIIa) is currently administered off-label to control diffuse coagulopathic bleeding of patients with traumatic injuries. These patients are often cold, acidotic, and coagulopathic upon arrival and each responds differently to rFVIIa therapy. This study investigated the effects of hypothermia on clotting and the potential benefit of rFVIIa administration on blood coagulation at different hypothermic temperatures.

METHOD

Citrated blood samples were collected from eight healthy volunteers (20-45 years old) and incubated at 37 degrees C, 34 degrees C, 31 degrees C, and 28 degrees C for 30 minutes. rFVIIa (1.26 microg/mL equivalent to 90 microg/kg in vivo dose) or vehicle solution (saline) was added to each blood sample, incubated (10 minutes), and analyzed at the respective temperatures by standard coagulation tests and thrombelastography.

RESULTS

The clot reaction time of blood samples, measured as prothrombin time, activated partial thromboplastin time, and R time (thrombelastography analysis), was significantly prolonged at 31 degrees C or below compared with at 37 degrees C. The clot formation rate ([alpha] angle, maximum clotting velocity [Vmax]) was decreased at all cold temperatures. Maximum clot strength (maximum amplitude) was only affected (reduced) at 28 degrees C. Addition of rFVIIa shortened the prothrombin time, activated partial thromboplastin time, and R times at every temperature, surpassing the normal (37 degrees C) temperature values in 31 degrees C and 34 degrees C cold samples. Similarly, clot formation rate parameters (clotting time, [alpha] angle, Vmax) were also improved by rFVIIa addition and normothermic values were restored in 31 degrees C and 34 degrees C cold blood samples. rFVIIa did not affect maximum amplitude at any temperature.

CONCLUSIONS

Mild to moderate hypothermia delayed the initial clot reaction and reduced clot formation rate without affecting ultimate clot strength. FVIIa effectively compensated for the adverse effects of hypothermia except in severe cases. These results suggest that administration of FVIIa should be beneficial in enhancing hemostasis in hypothermic trauma patients without the need for prior correction of the patient's body temperature.

[Recombinant factor VIIa (rFVIIa). Description of use in a cohort of critical patients and prognostic markers]

OBJECTIVE

Describe and identify the factors associated with the survival of the patients who received treatment with rFVIIa in an Intensive Care Unit (ICU).

DESIGN

Longitudinal, ambispective, observational, descriptive study in a series of clinical cases performed from July 20, 2004 to July 20, 2006.

SCOPE

The study population included 16 hospitalized patients in the Intensive Medicine Department (ICU) of the Hospital Marqués de Valdecilla (Santander).

PATIENTS

Inclusion criteria were: Patients who required rFVIIa at some time of their stay in the ICU.

RESULTS

Hemodynamic improvement of the patients treated with rFVIIa in an ICU, within the first 3 hours of the infusion (evaluated by an increase of SBP > 20 mmHg and/or increase of DBP > 8 mmHg) was associated to greater survival.

CONCLUSIONS

The present series of cases, with the disadvantage of its heterogeneity and the limited number of patients, stresses the role of hemodynamic improvement as a differentiating factor between those patients who survive and those who do not.

Use of recombinant activated factor VII in intractable bleeding during pediatric neurosurgical procedures

OBJECTIVE:: To report the use of recombinant activated factor VII (NovoSeven; Novo Nordisk A/S, Bagsvaerd, Denmark) in children undergoing major neurosurgical procedures and experiencing massive uncontrolled hemorrhagic shock. DESIGN:: Retrospective review of patients and analysis of clinical and biological effects of an intravenous administration of recombinant activated factor VII. SETTING:: Neurosurgical anesthesia and critical care unit of a pediatric university hospital. PATIENTS/SUBJECTS:: Four children, <12-kg body weight, experiencing life-threatening perioperative hemorrhage required conventional treatment (massive red blood cells, fresh frozen plasma, platelet transfusion, and surgical hemostatic maneuvers) that failed to obtain definite hemostasis. INTERVENTIONS:: Intravenous administration of recombinant activated factor VII (100 mug/kg). RESULTS:: Intravenous administration resulted in a significant decrease in blood loss within minutes (preventing further need of transfusion), normalization of biological hemostasis markers, and improved surgical hemostasis. No side effects of recombinant activated factor VII were noted, and all patients, except one, had a good recovery. CONCLUSIONS:: These four patients support the use of recombinant activated factor VII as a useful adjunct to control massive life-threatening bleeding during pediatric neurosurgical procedures when other means failed. However, the data are still limited in children, and more extensive research is needed to define the indications of recombinant activated factor VII in massive surgical hemorrhage in low-weight children.

Recombinant factor VIIa (rFVIIa): its potential role as a hemostatic agent

Recombinant activated coagulation factor VII (rFVIIa) was developed for the treatment of patients with hemophilia who have developed inhibitors against the factor they are missing. Hemophilia is a serious bleeding disorder and patients with hemophilia develop repeated spontaneous CNS, joint and muscle bleeding. Any trauma, even mild events, may cause life-threatening bleeding, and without treatment, these patients have a life expectancy of about 16 years. Thus, hemophilia can be regarded as a model of severe bleeding, and an agent capable of inducing hemostasis in severe hemophilia independent of the hemophilia proteins (FVIII or FIX) may also be effective in patients without hemophilia who experience serious bleeds. The availability of rFVIIa stimulated research on the role of FVII and tissue factor (TF) in the hemostatic process. As a result, a picture partly different from the one suggested by previous models has emerged. These previous models basically neglected the role of cells and cell membranes. The importance of platelets and platelet membrane phospholipids in hemostasis has been demonstrated, and the new concept of the hemostatic process, focusing on cell surfaces, has been outlined.

[Systemic hemostatic drugs]

Understanding the haemostatic changes is crucial in developing strategies for the management of haemorrhage syndroma. In recent years, the revised model of coagulation ("cell based" model) provided a much more authentic description of the coagulation process. Pharmacological intervention, especially desmopresin, antifibrinolytics (synthetics and nature) and increasingly recombinant activated factor VII are being used in prevention and therapeutically to control bleeding of variety etiologies. Skillfull surgery combined with blood saving methods and careful management of blood coagulation will all help in sucessfull haemorrhage prevention and treatment, and reduce unnecessary blood loss and transfusion requirements and its attendant risks. Among the all avalaible tests, the use of thromboelastography has allowed for more detailed dynamic assessment of the various steps of hemostasis.

Use of activated recombinant factor VII for severe coagulopathy post ventricular assist device or orthotopic heart transplant

BACKGROUND

Ventricular assist devices(VAD) implantation/removal is a complex surgical procedure with perioperative bleeding complications occurring in nearly half of the cases. Recombinant activated factor VII (rFVIIa) has been used off-label to control severe hemorrhage in surgery and trauma. We report here our experience with rFVIIa as a rescue therapy to achieve hemostasis in patients undergoing orthotopic heart transplant (OHT) and/or VAD implantation.

METHODS

A retrospective review was conducted from Jan 03 to Aug 05 for patients who received rFVIIa for the management of intractable bleeding unresponsive to standard hemostatic blood component therapy. Blood loss and the quantity of blood products, prior to, and for at least 12 hours after, administration of rFVIIa were recorded.

RESULTS

Mean patient age was 53, (38-64 yrs), mean dose of rFVIIa administered was 78.3 microg/kg (24-189 microg/kg) in 1-3 doses. All patients received the drug either intraoperatively or within 6 hours of arrival in ICU. Mean transfusion requirements and blood loss were significantly reduced after rFVIIa administration (PRBC's; 16.9 +/- 13.3 to 7.1 +/- 6.9 units, FFP; 13.1 +/- 8.2 to 4.1 +/- 4.9 units, platelets; 4.0 +/- 2.8 to 2.1 +/- 2.2 units, p < 0.04 for all). 5 patients expired including 3 with thromboembolic cause. One patient developed a lower extremity arterial thrombus, and another deep vein thrombosis.

CONCLUSION

In this review, there was a significant decrease in transfusion requirement and blood loss after rFVIIa administration. Although, 5/17 developed thromboembolic complications, these patients may have been at higher risk based on the multiple modality therapy used to manage intractable bleeding. Nevertheless, the exact role of rFVIIa with respect to development of thromboembolic complications cannot be clearly determined. Further investigation is needed to determine rFVIIa's safety and its effectiveness in improving postoperative morbidity and mortality.

The role of recombinant factor VIIa in on-pump cardiac surgery: Proceedings of the Canadian Consensus Conference

PURPOSE

Recombinant activated factor VII (rFVIIa) is currently not approved by Health Canada or the Food and Drug Administration for treating excessive blood loss in nonhemophiliac patients undergoing on-pump cardiac surgery, but is increasingly being used "off-label" for this indication. A Canadian Consensus Conference was convened to generate recommendations for rFVIIa use in on-pump cardiac surgery.

METHODS

The panel undertook a literature review of the use of rFVIIa in both cardiac and non-cardiac surgery. Appropriateness, timing, and dosage considerations were addressed for three cardiac surgery indications: prophylactic, routine, and rescue uses. Recommendations were based on evidence from the literature and derived by consensus following recognized grading procedures.

RESULTS

The panel recommended against prophylactic or routine use of rFVIIa, as there is no evidence at this time that the benefits of rFVIIa outweigh its potential risks compared with standard hemostatic therapies. On the other hand, the panel made a weak recommendation (grade 2C) for the use of rFVIIa (one to two doses of 35-70 microg.kg(-1)) as rescue therapy for blood loss that is refractory to standard hemostatic therapies, despite the lack of randomized controlled trial data for this indication.

CONCLUSIONS

In cardiac surgery, the risks and benefits of rFVIIa are unclear, but current evidence suggests that its benefits may outweigh its risks for rescue therapy in selected patients. Methodologically rigorous studies are needed to clarify its riskbenefit profile in cardiac surgery patients.

Coronary artery stents and non-cardiac surgery

The utility of interventional cardiology has developed significantly over the last two decades with the introduction of coronary angioplasty and stenting, with the associated antiplatelet medications. Acute coronary stent occlusion carries a high morbidity and mortality, and the adoption of therapeutic strategies for prophylaxis against stent thrombosis has major implications for surgeons and anaesthetists involved in the management of these patients in the perioperative period. Currently, there is limited published information to guide the clinician in the optimal care of patients who have had coronary stents inserted when they present for non-cardiac surgery. This review examines the available literature on the perioperative management of these patients. A number of key issues are identified: the role of surgery vs percutaneous coronary intervention for coronary revascularization in the preoperative period; the different types of coronary stents currently available; the emerging issues related to drug-eluting stents; the pathophysiology of coronary stent occlusion; and the recommended antiplatelet regimes that the patient with a coronary stent will be receiving. The role of preoperative platelet function testing is also discussed, and the various available tests are listed. Appropriate management by all the clinicians involved with patients with coronary stents undergoing a variety of non-cardiac surgical procedures is essential to avoid a high incidence of postoperative cardiac mortality and morbidity. The review examines the evidence available for the perioperative strategies aimed at reducing adverse outcomes in a number of different clinical scenarios.

A study of blood product use in patients with major trauma in Scotland: analysis of a major trauma database

OBJECTIVES

(1) To define blood product requirements in patients with trauma whose underlying injuries are consistent with major blood loss; (2) to use these data to estimate the annual number of patients in Scotland who sustain significant trauma and require substantial blood product replacement; and (3) to place these data in the context of recent findings concerning the efficacy of recombinant factor VIIa in patients with major trauma.

METHODS

A retrospective case note review study was conducted for patients who presented with trauma at each of four Scottish hospitals. The four sites were selected from the 26 hospitals that were the source of data for the Scottish Trauma Audit Group (STAG) database. Collected between 1991 and 2002, STAG encompasses approximately 53 000 patients. 129 patients whose trauma codes were likely to be linked to injuries associated with major blood loss were selected. Data on the use of blood products for each patient were collected and analysed for three periods: (1) time spent in the emergency department (ED); (2) time from leaving the ED to the end of the first 24 h; and (3) time from the end of the first 24 h to 7 days. Blood product use for each period and for the entire first week of care was described for all patients and for blunt and penetrating injury subgroups. Using national population data estimates, the incidence of major trauma requiring blood transfusion was calculated for Scotland.

RESULTS

Among the patients with trauma codes predicting significant blood loss, the proportion of patients requiring any blood transfusion within the first 7 days was 53.9%. 27.4% of patients received > or =8 units of red cell concentrate (RCC) within the first 24 h of hospitalisation. By direct extrapolation, we estimated that the annual number of Scotland's patients (aged >13 years) with a significant blood transfusion requirement secondary to traumatic injury was 67. Of these, 35 patients would require > or =8 units of RCC within the first 24 h.

CONCLUSION

In summary, this study estimates that approximately 67 patients annually in Scotland, above the age of 13 years, require blood transfusion as a direct result of significant traumatic injury. Of these 67 patients, an estimated 35 patients (28 of whom had a blunt form of trauma) require > or =8 units of RCC during the first 24 h in hospital. On the basis of the current limited trial evidence, the potential benefit in using recombinant factor VIIa in such patients, in Scotland, is small-approximately seven patients per million population aged >13 years, per year.

Recombinant Activated Factor VII in Cardiac Surgery: A Systematic Review

Postoperative hemorrhage is a common complication in cardiac surgery, and it is associated with a considerable increase in morbidity, mortality, and cost. Recombinant activated factor VII (rFVIIa) is an emerging hemostatic agent, increasingly used in cardiac surgery. This article systematically reviews the evidence regarding the efficacy, safety, and cost of rFVIIa in this setting. Although definitive evidence from randomized controlled trials is lacking, the use of rFVIIa in patients experiencing refractory postoperative hemorrhage seems promising and relatively safe. However further research is required to definitively establish its clinical utility in the postoperative cardiac patient.

Recombinant activated coagulation factor VII and bleeding trauma patients

BACKGROUND

Recombinant activated coagulation factor VII (rFVIIa) is increasingly being administered to massively bleeding trauma patients. rFVIIa has been shown to correct coagulopathy and to decrease transfusion requirements. However, there is no conclusive evidence to suggest that rFVIIa improves the survival of these patients. The purpose of this study was to determine whether or not rFVIIa has an effect on the in-hospital survival of massively bleeding trauma patients.

METHODS

A retrospective cohort study was conducted from January 1, 2000 to January 31, 2005, at a Level I trauma center in Toronto, Canada. Inclusion criteria included trauma patients requiring transfusion of 8 or more units of packed red cells within the first 12 hours of admission. The primary exposure of interest was the administration of rFVIIa. Primary outcome was a 24-hour survival and secondary outcome was overall in-hospital survival.

RESULTS

There were 242 trauma patients identified who met inclusion criteria; 38 received rFVIIa. rFVIIa patients were younger, had more penetrating injuries, and fewer head injuries. However, rFVIIa patients required more red cell transfusions initially, and were more acidotic. Administering rFVIIa was associated with improved 24-hour survival, after adjusting for baseline demographics and injury factors. The odds ratio (OR) for survival was 3.4 (1.2-9.8). Furthermore, there was a strong trend toward increased overall in-hospital survival. The OR of in-hospital survival was 2.5 (0.8-7.6). Also, subgroup analysis of rFVIIa patients showed that 24-hour survivors required a slower initial rate of red cell transfusion (4.5 vs. 2.9 units/hr, p = 0.002), had higher platelet counts (175 vs. 121 [x10(-9)/L], p = 0.05) and smaller base deficits (7.1 vs. 14.3, p = 0.001) compared with rFVIIa patients who died during the first 24 hours.

CONCLUSION

rFVIIa may be able to improve the early survival of massively bleeding trauma patients. However, surgical control of massive hemorrhage still has primacy, as rFVIIa did not appear efficacious if extremely high red cell transfusion rates were required. Also, correction of acidosis and thrombocytopenia may be important for rFVIIa efficacy. Prospective studies are required.

Rescue treatment with recombinant factor VIIa is effective in patients with life-threatening bleedings secondary to major wound excision: a report of four cases

Major burn wound excision is associated with excessive perioperative blood loss. Treatment of massive microvascular bleeding represents a special problem in the burn setting, characterized by extensive damage at the capillary level, and resulting in a profound blood loss; which together with the consumptive states makes adequate replacement therapy with coagulation factors and platelets difficult. We described our experience with rescue treatment with rFVIIa in four patients undergoing major wound excision, developing life-threatening perioperative bleeding, and not responding to conventional therapy. Hemostasis was achieved within 15 minutes of intravenous rFVIIa administration, at a dose of 100 microg/kg, in all patients. No treatment-related adverse events, in particular, no thromboembolic events were observed. We conclude that rFVIIa may be an effective hemostatic treatment for patients undergoing major wound excision developing life-threatening bleedings.

Pathophysiology of bleeding in surgery

Bleeding is a major surgical complication. Although mortality rates of 0.1% are observed for surgical procedures, it may be 5% to 8% for elective vascular surgery, and increase to 20% in the presence of severe bleeding. In major surgery for liver diseases, as well as in cardiac surgery, excessive blood loss is associated with increased mortality, morbidity, and intensive care stay. Approximately 75% to 90% of intraoperative and early postoperative bleeding is due to technical factors. However, in some cases either acquired or congenital coagulopathies may favor, if not directly cause, surgical hemorrhage. Uncontrolled bleeding leads to a combination of hemodilution, hypothermia, consumption of clotting factors, and acidosis, which in turn worsen the clotting process, further exacerbating the problem in a vicious bloody circle. At present, the standard treatment for surgical bleeding is the rapid control of the source of bleeding by either surgical or radiological techniques. Blood-derived products as well as hemostatic agents, such as aprotinin, tranexamic acid, and DDAVP, are widely used to improve hemostatic balance in bleeding patients. Recombinant activated factor VII (rFVIIa) has been reported to be effective for the treatment of surgical or traumatic massive bleeding unresponsive to conventional therapy. Although most reports are anecdotal, and therefore exposed to a "positive" selection bias, the number of cases is impressive, strongly suggesting that in such patients rFVIIa may afford a hemostatic advantage beyond that of conventional replacement therapy.

Mechanism of action, development and clinical experience of recombinant FVIIa

Recombinant FVIIa has been developed for treatment of bleedings in hemophilia patients with inhibitors, and has been found to induce hemostasis even during major surgery such as major orthopedic surgery. Recombinant FVIIa is being produced in BHK cell cultures and has been shown to be very similar to plasma-derived FVIIa. The use of rFVIIa in hemophilia treatment is a new concept of treatment and is based on the low affinity binding of FVIIa to the surface of thrombin activated platelets demonstrated in a cell-based in vitro model. By the administration of pharmacological doses of exogenous rFVIIa the thrombin generation on the platelet surface at the site of injury is enhanced independently of the presence of FVIII/FIX. As a result of the increased and rapid thrombin formation, a tight fibrin hemostatic plug is being formed. A tight fibrin structure has been found to be more resistant to fibrinolytic degradation thereby helping to maintain hemostasis. The general mechanism of action of pharmacological doses of rFVIIa shown to induce hemostasis not only in hemophilia, but also in patients with platelet defects, and with profuse bleedings triggered by extensive surgery or trauma, may very well be the capacity of generating a tight fibrin hemostatic plug through the increased thrombin generation. Such a fibrin plug will help to resist the overwhelming mostly local release of fibrinolytic activity triggered by the vast tissue damage occurring in extensive trauma. A release of fibrinlytic activity locally has also been demonstrated to occur in the gastrointestinal tract as well as during profuse postpartum bleedings. Pharmacological doses of rFVIIa have in fact, also been shown to induce hemostasis in such cases.

The Clinical and Laboratory Response to Recombinant Factor VIIa in Trauma and Surgical Patients with Acquired Coagulopathy

OBJECTIVE

In bleeding patients who are coagulopathic, the clinical response to administration of recombinant factor VIIa (rFVIIa) relates to the changes in prothrombin time (PT).

DESIGN

Retrospective review of all surgical and trauma patients who were coagulopathic and received factor VIIa at the authors' institution over the past 27 months.

SETTING

Academic tertiary referral facility and level I trauma center.

PARTICIPANTS

Eighteen patients met inclusion criteria, 10 trauma and 8 surgical. Mean age 50 years (range, 17-84).

RESULTS

Overall mortality was 39%. All but 1 patient (17/18) had resolution of coagulopathic bleeding with rFVIIa, and all clinical responders (n = 17) (defined as clinical cessation of bleeding within 24 hours determined by either attending surgeon or chief resident progress note) had a decrease in PT to normal range. In contrast, the single clinical nonresponder had an insignificant PT decrease (19 to 18 seconds). Prothrombin time decreased from 20 +/- 4 seconds to 12 +/- 2 seconds, p < 0.05 (n = 17). International Normalized Ratio (INR) decreased from 1.59 to 0.86, p < 0.05 (n = 17). Fibrinogen before administration was 299.73 (range, 105-564) (n = 15). pH before administration was 7.25 (+/-0.18) (n = 10). Patient temperature was 98.64 (+/-2.06). Effect in partial thromboplastin time (PTT) was inconsistent (50 +/- 49 seconds to 34 +/- 6 seconds, p > 0.05). Transfusion requirements for red blood cells (14 to 3 units) and plasma (12 to 3 units) were significantly reduced after rFVIIa. There were no significant differences in percentage PT decrease between dose > or =100 mcg/kg vs <100 mcg/kg, surgical vs trauma patients, survivors vs nonsurvivors, and those with pretreatment platelet count > or =100 K vs <100 K.

CONCLUSIONS

The administration of rFVIIa caused a decrease in the PT in nearly all patients. There were an insufficient number of patients to support the use of PT as a clinical predictor of response; however, the data are suggestive of such utility. If the PT does not correct, then it is likely that there is a deficiency of other factors of the coagulation cascade.

Recombinant activated factor VIIa in uncontrolled bleeding: a haemostasis laboratory study in non-haemophilia patients

Extensive surgery and massive tissue trauma are often associated with severe bleeding. We present retrospective data on the use of recombinant factor VIIa in haemostatic emergencies in13 non-hemophilia patients with uncontrolled bleeding. Recombinant factor VIIa was administered in doses ranging from 16 mug/kg bodyweight to 60 microg/kg bodyweight. Blood loss during 24 h before and after the infusion was registered, showing that 10 out of 13 patients (77%) had a 70% or greater reduction in transfusion requirement decreasing significantly in mean from 28.1 to 9.9 red blood cell units. Coagulation parameters were studied in blood samples collected 10 min before and 10-15 min after the injection of recombinant factor VIIa. Factors VII:C, II:C, and X:C increased significantly while the activated partial thromboplastin time, platelet numbers, and concentration of fibrinogen and D-dimers were unchanged. The dose of rFVIIa correlated significantly with the rise in factor X:C and inversely with transfusion requirements. Dynamic clot velocity of whole blood was recorded before and after rFVIIa infusion in four patients. Judged from red blood cell usage no improvement in haemostasis was seen in one patient suffering thrombocytopenia and low fibrinogen. This patient died 6 h after recombinant factor VIIa infusion, and three other patients died before 1 month. None of the fatalities appeared to be related to recombinant factor VIIa usage. No thromboembolic complications were seen. In conclusion, 12 out of 13 patients survived the first 24 h after treatment with relatively low doses of recombinant factor VIIa for large-scale bleeding. Recombinant factor VIIa was well tolerated and safe in these non-hemophilia patients. With quite low doses of recombinant factor VIIa (<or= 60 microg/kg), the dose of recombinant factor VIIa correlated positively with efficacy. Activation of factor X appeared to predict haemostatic efficacy.

Human recombinant factor VII for emergency reversal of coagulopathy in neurosurgical patients: a retrospective comparative study

OBJECTIVE

Severe coagulopathy in a neurosurgical patient with intracranial hemorrhage is a common and serious problem. Current therapy with vitamin K and fresh-frozen plasma (FFP) may be too slow in certain situations. There are reports of rapid reversal of coagulopathy using human recombinant factor VII. We present a retrospective controlled study of our experience with factor VII.

METHODS

We used factor VII as a second-line therapy after initial attempts at reversal with FFP had failed. Factor VII was given to 29 patients in the neurosurgical intensive care unit; 24 patients treated before the introduction of factor VII were control subjects. The groups were matched by age, sex, cause of coagulopathy, and presence of intracranial hemorrhage.

RESULTS

After initial FFP administration, the international normalized ratio (INR) changed from a mean of 2.57 to 1.67 in the factor VII group and from 2.17 to 1.85 in control subjects. In all patients, INR tended to rebound. Before administration of factor VII, the mean INR was 2.206. After 1.4 mg of factor VII, mean INR decreased to 1.12 (P < 0.05). Measured from admission, INR in the factor VII group normalized within 6.78 +/- 2.68 hours, and in control subjects, within 47.44 +/- 9.88 hours (P < 0.0005). Six factor VII patients and six control subjects died. The number of patients with good functional outcome (Glasgow Outcome Scale score of 5) was greater among patients treated with factor VII compared with those who received only vitamin K and FFP (nine versus two, P = 0.04). None of the deaths were the result of a thrombotic complication. There were no thrombotic complications in the factor VII group.

CONCLUSION

Factor VII is safe and highly effective when emergency reversal of coagulopathy is desired and may improve the functional outcome. We speculate that the use of factor VII as first choice may result in decreased use of FFP and thus increase patient safety.

Small-Dose Recombinant Activated Factor VII (NovoSeven??) in Cardiac Surgery

Recombinant activated factor VII (rFVIIa) has been used at different doses in cardiac surgery patients. We tested the efficacy of small-dose rFVIIa in patients with intractable bleeding after cardiac surgery. The study group comprised 15 cardiac surgery patients with intractable bleeding treated with small-dose (1.2 mg) rFVIIa as a slow IV bolus at the end of complete step-by step transfusion protocol. Fifteen matched patients undergoing the same transfusion protocol in the pre-rFVIIa era represented the control group. Blood loss at the end of the transfusion protocol was a primary outcome. Median, 25th-75th 24-h blood loss percentiles were 1685 (1590-1770) mL versus 3170 (2700-3850) mL in study group and controls, respectively (P = 0.0004). Transfused red blood cells, fresh-frozen plasma, and platelets in the study group and controls were as follows: 7 (4-8) U versus 18 (12-21) U (P = 0.001); 7.5 (6-11) U versus 11 (9-15) U (P = 0.003); 0 (0-4) U versus 9 (6-13) U (P = 0.001). In addition, significant improvements of prothrombin time (P = 0.015), international normalized ratio (P = 0.006), activated partial prothrombin time (P = 0.01), and platelet count (P = 0.003) were detected in the study group versus controls. Finally, patients receiving rFVIIa showed a reduced intensive care unit length of stay (chi2 = 15.9, P = 0.0001) and had infrequent surgical re-exploration (chi2 = 16.2,P < 0.0001). Small-dose rFVIIa showed satisfactory results in cardiac patients with intractable bleeding. Further randomized studies are necessary to confirm our findings.

Traumatic Hemoptysis Treated With Recombinant Human Factor VIIa

Blunt thoracic trauma resulting in massive hemoptysis is rare. Although there are several indications for the administration of recombinant factor VIIa, we are unaware of a report of its utilization in the treatment of hemoptysis following chest trauma. We report a case of the successful use of factor VIIa in the treatment of life-threatening hemoptysis secondary to blunt force thoracic injury and traumatic coagulopathy.

Recombinant Activated Factor VII: Treating Postoperative Hemorrhage in Cardiac Surgery

BACKGROUND

The purpose of this study is to review the effect of recombinant activated factor VII (rFVIIa) as rescue therapy in continuing severe postoperative hemorrhage, despite conventional measures in a series of cardiac patients at our institution.

METHODS

A series of all patients who received rFVIIa as rescue therapy for uncontrollable postoperative hemorrhage after cardiac surgery over a 2-year period was analyzed. We assessed and compared the use of blood products, coagulation indicators (international normalized ratio [INR], activated partial thromboplastin [APTT], and fibrinogen), and platelet levels immediately before and after the rFVIIa was given.

RESULTS

Twelve patients received rFVIIa. Eight patients (75%) had thoracic aortic surgery. Bleeding stopped in all cases. Prior to the administration of rFVIIa, mean blood product usage was the following: fresh frozen plasma (FFP) 18.7 units (range, 10-40); packed cells 7.7U (range, 0-18); cryoprecipitate 19.5U (range, 8-32); and platelets 22.5U (range, 10-40). The mean coagulation results immediately prior to rFVIIa were the following: INR 2.0 (range, 1.3-8.5); APTT 60 seconds (range, 30-220); fibrinogen 3.2 gm/L (range, 1.6-6.4), and platelet count was 174,000 (range, 78,000-257,000). After rFVIIa administration the mean blood product usage was the following: FFP 0U (range, 0-2); red cells 0U (range, 0-1); cryoprecipitate 0 (range, 0); and platelets 0 (range, 0); p less than 0.0005. The mean INR was 0.9 (range, 0.7-1.5), p less than 0.001; mean APTT was 42 seconds (range, 30-87), mean fibrinogen was 3.1 (range, 1.7-4.5), and the mean platelet count was 170,000 (range, 93,000-289,000); p values not significant. There were no thrombotic complications, no cardiac ischemic events, and no deaths.

CONCLUSIONS

Our results support the use of rFVIIa as rescue therapy in severe, uncontrollable, nonsurgical, postoperative hemorrhage after cardiac surgery as efficacious and safe.

Recombinant activated factor VII (rFVIIa/NovoSevenR) in intractable haemorrhage: use of a clinical scoring system to predict outcome

BACKGROUND AND OBJECTIVES

Recombinant activated factor VII (rFVIIa/NovoSeven) has been advocated in the treatment of life-threatening haemorrhage, but appropriate clinical indications remain uncertain. The aim of this study was to detect factors predictive of outcome and to incorporate them into a prognostically significant scoring system.

MATERIALS AND METHODS

Thirty-six patients received rFVIIa for uncontrolled surgical, traumatic or obstetric bleeding in the Northern Region of the UK over a 45-month period. Clinical, laboratory and outcome data were examined. Characteristics of survivor and non-survivor groups were compared. A prognostic scoring system was evaluated retrospectively according to the presence of coagulopathy, renal impairment, hypothermia, greater than 10 units of red cell transfusion, advanced age and obstetric indication, with patients allocated to low, intermediate and high-risk groups.

RESULTS

Clinical response occurred in 26 patients (72%) with a reduction in prothrombin time and blood product requirements. Death occurred in 19 (53%). Four patients (11%) suffered thrombotic events. Survivors were younger than non-survivors and less likely to have coagulopathy, renal impairment or hypothermia at the time of administration. Survivors were more likely to have had an initial clinical response in terms of an immediate reduction in haemorrhage. Non-survivors were transfused a greater number of red cell units prior to administration. Survival varied according to prognostic score; low-risk patients had a survival rate of 85%, intermediate-risk patients had a survival rate of 50% and high-risk patients had a survival rate of 18%.

CONCLUSIONS

FVIIa has a role in the cessation of haemorrhage, but may not improve survival. Use of a clinical scoring system may help to predict outcome.

The emerging role of recombinant activated Factor VII (rFVIIa) in the treatment of blunt traumatic haemorrhage

Recombinant activated Factor VII (rFVIIa; eptacog alpha [activated], NovoSeven) is currently used for the management of a subgroup of haemophilia patients with inhibitors to Factors VIII or IX, and is under investigation as an adjuvant therapy for critical bleeding from other causes, including trauma. rFVIIa has a mode of action founded on physiological coagulation processes, and causes localised haemostasis at injury sites, both spontaneous and traumatic, with the capacity to correct the systemic coagulopathy associated with massive blood loss and its management. This review charts the development of rFVIIa as a new and potent adjuvant therapy for severe bleeding and coagulopathy caused by blunt trauma, where it is reported to produce rapid and significant haemostasis, reducing transfusion requirements and improving clinical outcome.

Mechanistic implications for the use and monitoring of recombinant activated factor VII in trauma

As interest in the use of activated recombinant factor VII (rFVIIa) in trauma grows, questions arise regarding how best to monitor rFVIIa therapy and when rFVIIa may be expected to improve hemostasis. Knowledge of the mechanisms of action may be combined with available data on laboratory monitoring and efficacy in various coagulopathic states in coming to clinically relevant conclusions. This review addresses the physiology of hemostasis, placing emphasis on how rFVIIa influences the process by both tissue factor dependent and tissue factor independent mechanisms. This is extended to a mechanistic consideration of how rFVIIa may function under acidotic, hypothermic, and hemodilutional and/or consumptive conditions of trauma related coagulopathy. When these considerations are viewed alongside the available clinical data, it becomes apparent that rFVIIa has potential to improve hemostasis during trauma coagulopathy, within limitations. Common laboratory procedures are discussed with reference to mechanisms of action of rFVIIa and the available clinical data. Although there is no single assay that can predict rFVIIa efficacy in trauma, the prothrombin time (PT) is recommended as a minimum. Although a shortened PT does not predict success, correction of PT into the normal range may be a better indicator. A nonresponding PT appears to indicate that rFVIIa alone will not lead to hemostasis, and that additional blood products and other measures must be applied. Once the patient is more stable, PT and thromboelastography are recommended.

Recombinant activated factor VIIa and hemostasis in critical care: a focus on trauma

In this article we describe the current use of recombinant activated factor VII (rFVIIa; NovoSeven) in trauma patients. Emphasis is placed on current uses as defined by key studies, efficacy data, and safety data. Most published studies in trauma patients are retrospective case studies and reports, although an international, double-blind, randomized, controlled, phase II study has been conducted that reported on the efficacy of rFVIIa in reducing the amount of blood products transfused in blunt trauma patients. That study demonstrated the efficacy and safety profile of this hemostatic agent as compared with placebo as adjunctive therapy in the management of severe bleeding associated with trauma. Further prospective, randomized, and placebo-controlled clinical trials will yield more information on the role of rFVIIa in the management of traumatic bleeding.