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

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.

Recombinant factor VIIa reduces rebleed hemorrhage volume in a swine aortotomy model: a randomized double-blinded study

Noncompressible hemorrhage requires hypotensive resuscitation until definitive measures can be taken to prevent rebleeding by sustaining blood pressure at subphysiological levels. Previous studies have demonstrated that a 180- or 720-microg kg(-1) dose of recombinant factor VIIa (rFVIIa) increases the MAP at which rebleeding occurs in a swine aortotomy model. The purpose of the current study was to determine the efficacy of a lower dose of 90 microg kg(-1) given prophylactically to prevent or reduce rebleeding in a prospective, randomized, blinded study using a porcine model of uncontrolled hemorrhage and resuscitation. Fourteen female 40-kg Yorkshire-cross pigs were splenectomized and instrumented with venous and arterial catheters. The infrarenal aorta was exposed, and suction catheters were placed along the right and left paracolic gutters. After a 10-min baseline, 90 microg kg(-1) (i.v.) of either rFVIIa (n = 6) or vehicle (n = 8) was administered. Five minutes later, an aortotomy was created using a 2.5-mm biopsy punch. The weight of the shed blood was continuously recorded. Lactated Ringer's was given (100 mL kg(-1) min(-1)) 10 min after aortotomy until rebleeding occurred. The MAP at rebleed and the subsequent rebleed hemorrhage volume was recorded over the 2-h study period. After rebleed occurred, lactated Ringer's sufficient to maintain MAP at baseline levels was given. Initial hemorrhage volume and rebleed MAP (P = 0.31) did not differ significantly between groups. Rebleed hemorrhage volume was reduced by 54% in the rFVIIa group from 79 +/- 4 mL kg(-1) in the vehicle group to 43 +/- 6 mL kg(-1) in the rFVIIa group (mean +/- SEM; P < 0.005). The MAP at which rebleed occurred was not different between the groups, 71 +/- 4 mmHg in the rFVIIa group versus 59 +/- 5 in the vehicle group. Prophylactic administration of rFVIIa at 90 microg kg(-1), a dose similar to the recommended dose in hemophilia patients with inhibitors, reduced rebleed hemorrhage volume, suggesting that this dose is effective in this swine aortotomy model.

Dosing factor VIIa (recombinant) in nonhemophiliac patients with bleeding after cardiac surgery

PURPOSE

The dosing of factor VIIa (recombinant) in nonhemophiliac patients with cardiac-surgery-associated bleeding (CSAB) is discussed.

SUMMARY

Factor VIIa (recombinant) is a vitamin K-dependent glycoprotein that is FDA-approved for use in patients with hemophilia A or B with inhibitors to factor VIII or IX and for patients with factor VII deficiency. Case reports and observational studies indicate that factor VIIa (recombinant) may be efficacious for the treatment of acute bleeding episodes related to trauma, surgery, and coagulopathies. The use of factor VIIa (recombinant) for CSAB is increasing. No controlled clinical trials have been conducted to determine the safety and efficacy of factor VIIa (recombinant) in the treatment of CSAB; therefore, the appropriate dosing scheme remains unclear. In addition, thromboembolic events associated with factor VIIa (recombinant) have been reported, so the safety of factor VIIa (recombinant) in patients with normal coagulation systems is unclear. Data from one randomized, controlled, clinical trial of the use of factor VIIa (recombinant) in intracerebral hemorrhage showed a dose-related trend toward adverse events when factor VIIa (recombinant) was compared with placebo.

CONCLUSION

No particular dose of factor VIIa (recombinant) is strongly supported in the literature for off-label use, and thromboembolic events may be dose dependent. Use of the smallest possible dose is warranted because of the high cost of factor VIIa (recombinant) and the potential for thromboembolic events. A single dose of 2.4 or 4.8 mg or 45 microg/kg should be considered.

Safety and efficiency of recombinant activated factor VII in postcardiotomy massive hemorrhage

Postoperative massive hemorrhage is a difficult clinical situation after cardiac surgery. Recombinant activated factor VII (rf-VIIa) can be a useful adjunct to surgical hemostasis and blood product transfusion. Four cases of massive hemorrhage treated with rf-VIIa after complex cardiac surgery are reported. A review of the literature and possible guidelines for the use of rf-VIIa in cardiac surgery are provided.

Blood management

CONTEXT

We provide an overview of the principles of blood management: the appropriate use of blood and blood components, with a goal of minimizing their use.

OBJECTIVE

To review the strategies that exploit combinations of surgical and medical techniques, technologic devices, and pharmaceuticals, along with an interdisciplinary team approach that combines specialists who are expert at minimizing allogeneic blood transfusion.

DATA SOURCES

A search on Medline and PubMed for the terms English and humans used in articles published within the last 20 years.

CONCLUSIONS

Blood management is most successful when multidisciplinary, proactive programs are in place so that these strategies can be individualized to specific patients.

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.

Recombinant activated factor VII for refractory bleeding after acute aortic dissection surgery: A propensity score analysis*

OBJECTIVE

The aim of this study was to assess safety and effectiveness of recombinant activated factor VII (rFVIIa) in patients with refractory bleeding undergoing acute aortic dissection surgery with deep hypothermic circulatory arrest.

DESIGN

Propensity score-matched analysis.

SETTING

University hospital.

PATIENTS

Twenty-three cardiac surgery patients receiving rFVIIa compared with 23 matched controls.

INTERVENTIONS

An intravenous bolus of rFVIIa (70 microg/kg) was administered at the end of a complete transfusion protocol. Five patients received rFVIIa in the operating room, and 18 patients received rFVIIa in the intensive care unit. Four of the intensive care unit patients required a second dose.

MEASUREMENTS AND MAIN RESULTS

Blood loss and transfusion requirements were significantly reduced in the period after rFVIIa administration. A highly significant reduction in hourly blood loss was found at -1 hr vs. 0 hrs and 0 hrs vs. 1 hr (-194 and -77.5 mL, respectively; both adjusted p < .001). In addition, significant improvements of international normalized ratio (p < .001), partial thromboplastin time (p < .001), platelet count (p < .001), fibrinogen (p < .001), and antithrombin (p < .001) were detected after rFVIIa administration. The two groups did not differ regarding adverse events.

CONCLUSIONS

rFVIIa was successfully used as an additional therapy both during and after acute aortic dissection surgery with deep hypothermic circulatory arrest, when bleeding was refractory to conventional methods. Randomized studies are necessary to confirm the safety and efficacy of rFVIIa in this setting.

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 VIIa (NovoSeven®): current development

Recombinant activated coagulation factor VII (rFVIIa) was developed initially for treatment of patients with hemophilia and neutralizing antibodies ("inhibitors") to coagulation factors VIII or IX. Owing to the unique and selective mechanism of action of rFVIIa and encouraged by clinical experience with other circumstances of inadequate hemostasis, a broad development program has been pursued to test potential efficacy and evaluate safety of this biologic for indications other than hemophilia. This review summarizes the current development of rFVIIa, focusing on results of prospective, randomized clinical trials.