An effective treatment of severe intractable bleeding after valve repair by one single dose of activated recombinant factor VII

Localization of Short-Chain Polyphosphate Enhances its Ability to Clot Flowing Blood Plasma

Short-chain polyphosphate (polyP) is released from platelets upon platelet activation, but it is not clear if it contributes to thrombosis. PolyP has increased propensity to clot blood with increased polymer length and when localized onto particles, but it is unknown whether spatial localization of short-chain polyP can accelerate clotting of flowing blood. Here, numerical simulations predicted the effect of localization of polyP on clotting under flow, and this was tested in vitro using microfluidics. Synthetic polyP was more effective at triggering clotting of flowing blood plasma when localized on a surface than when solubilized in solution or when localized as nanoparticles, accelerating clotting at 10-200 fold lower concentrations, particularly at low to sub-physiological shear rates typical of where thrombosis occurs in large veins or valves. Thus, sub-micromolar concentrations of short-chain polyP can accelerate clotting of flowing blood plasma under flow at low to sub-physiological shear rates. However, a physiological mechanism for the localization of polyP to platelet or vascular surfaces remains unknown.

Recombinant activated factor VIIa to treat refractory lower gastrointestinal hemorrhage in a patient with recently implanted mechanical valve: a case report

BACKGROUND

Bleeding is a common complication after cardiac surgery. However, lower gastrointestinal bleeding is not usually associated with this type of surgery.

CASE PRESENTATION

A 50-year-old man with a history of aortic regurgitation underwent elective mechanical valve replacement under cardiopulmonary bypass. He experienced a complicated intraoperative course involving unexplained cardiac arrest following induction of anesthesia. He also developed two episodes of massive lower gastrointestinal bleeding secondary to mucosal ischemia while convalescing in the cardiothoracic surgery intensive care unit. After unsuccessful attempts to control the bleeding, exhaustion of blood products, and consideration of the high risk of mortality associated with surgery and the possibility of early- and long-term surgical complications, the decision was made to administer two successive doses of recombinant activated factor VII at 60 mcg/kg. Hemostasis was achieved without adverse systemic or valvular effects.

CONCLUSIONS

A favorable outcome was achieved after administration of recombinant activated factor VII, which controlled the patient's severe lower gastrointestinal bleeding. This outcome suggests the need to raise awareness about the use of this drug in dire circumstances when other conventional measures fail or are unsuitable.

Recombinant activated factor VII in the treatment of intractable non-surgical bleeding following major vascular procedures

INTRODUCTION A recombinant form of activated factor VII (rFVIIa) is a haemostatic drug that is approved for use in haemophiliacs with antibodies to factor VIII or factor IX. Most recent studies and clinical experience have shown that rFVIIa (NovoSeven ?, Novo Nordisk A/S, Denmark) gives extreme haemostatic effect in patients with severe "non-haemophilic" bleeding produced after trauma and major surgery. OBJECTIVE We present our preliminary experience of the use of rFVIIa in vascular surgery when conventional haemostatic measures are inadequate. METHOD There were 32 patients divided into five groups: Group I - 14 patients with ruptured abdominal aortic aneurysms; Group II - 10 patients with thoracoabdominal aortic aneurysms; Group III - 5 patients with retroperitoneal tumors involving great abdominal vessels; Group IV - 2 patients with portal hypertension and Group V - one patient with iatrogenic injury of brachial artery and vein during fibrinolytic treatment, because of myocardial infarction. RESULTS Clinical improvement was detected following treatment in 29 patients. Bleeding was successfully controlled as evidenced by improved haemodynamic parameters and decreased inotropic and transfusion requirements. CONCLUSION In vascular patients more liberal use of rFVIIa is limited, because no randomized controlled trial has proved its efficacy and safety in such patients; while also keeping in mind that the price of a 4.8 mg of rFVIIa is $4,080. We recommend the use of rFVIIa in vascular surgery only during and after operative treatment of thoracoabdominal aortic aneurysms, ruptured abdominal aortic aneurysms, retroperitoneal tumors involving the aorta and/or inferior vena cava, as well as portal hypertension, when non-surgical massive uncontrolled bleeding are present.

Successful Graft Patency After Factor VIIa Use for Bleeding in Coronary Artery Surgery

There is a growing literature regarding the use of recombinant activated factor VII (rFVIIa) (NovoSeven, NovoNordisk, Copenhagen, Denmark) to control refractory hemorrhage after cardiopulmonary bypass in cardiac surgery. This supporting evidence is mostly documented as case reports on patients, of which only six involve coronary artery grafting. We present our experience of a patient undergoing coronary artery bypass grafting, who suffered an anaphylactic reaction to protamine preventing safe reversal of systemic heparinization. Subsequent management of postoperative bleeding was successfully achieved only after rFVIIa administration.

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.

[Recombinant factor VII (NovoSeven) in intraoperative blood saving during neurosurgical treatment of the brain arteriovenous malformation]

BACKGROUND

Cerebral arteriovenous (AV) malformation causes, due to the increased blood flow through a malformation, a massive intraoperative bleeding complicating, so, surgical treatment. The use of intraoperative blood saving apparatus during surgery and a recombinant factor VII-a (NovoSeven) significantly reduce complications during surgical treatment.

CASE REPORT

We reported a case of surgical treatment of the patient with AV malformation of IV stage according to the Spetzler-Martin scale, in the brain. Due to a possible heavy bleeding we used a apparatus for intrasurgical blood recovery, Cell Saver, Sequestra 1 000, Medtronic, U.S.A., and recombinant human factor VIIa (rFVIIa--NovoSeven, NovoNordisk, Denmark) to control bleeding and restore an adequate hemostasis.

CONCLUSION

The use of an apparatus for intraoperative blood saving, as well as the NovoSeven preparation in the management of AV malformation of IV stage, showed to be successful.

Massive transfusion and coagulopathy: pathophysiology and implications for clinical management

PURPOSE

To review the pathophysiology of coagulopathy in massively transfused, adult and previously hemostatically competent patients in both elective surgical and trauma settings, and to recommend the most appropriate treatment strategies.

METHODS

Medline was searched for articles on "massive transfusion," "transfusion," "trauma," "surgery," "coagulopathy" and "hemostatic defects." A group of experts reviewed the findings.

PRINCIPAL FINDINGS

Coagulopathy will result from hemodilution, hypothermia, the use of fractionated blood products and disseminated intravascular coagulation. The clinical significance of the effects of hydroxyethyl starch solutions on hemostasis remains unclear. Maintaining a normal body temperature is a first-line, effective strategy to improve hemostasis during massive transfusion. Red cells play an important role in coagulation and hematocrits higher than 30% may be required to sustain hemostasis. In elective surgery patients, a decrease in fibrinogen concentration is observed initially while thrombocytopenia is a late occurrence. In trauma patients, tissue trauma, shock, tissue anoxia and hypothermia contribute to the development of disseminated intravascular coagulation and microvascular bleeding. The use of platelets and/or fresh frozen plasma should depend on clinical judgment as well as the results of coagulation testing and should be used mainly to treat a clinical coagulopathy.

CONCLUSIONS

Coagulopathy associated with massive transfusion remains an important clinical problem. It is an intricate, multifactorial and multicellular event. Treatment strategies include the maintenance of adequate tissue perfusion, the correction of hypothermia and anemia, and the use of hemostatic blood products to correct microvascular bleeding.

Recombinant factor VIIa for refractory bleeding after cardiac surgery secondary to anticoagulation with the direct thrombin inhibitor lepirudin

A 56-year-old man with heparin-induced thrombocytopenia with thrombosis syndrome (HITTS) received anticoagulation with recombinant hirudin (lepirudin) for emergency coronary artery bypass graft (CABG) surgery and aortic valve replacement. The patient experienced life-threatening refractory bleeding that was successfully treated with recombinant factor VIIa. He had a history of infective endocarditis that resulted in severe aortic insufficiency, three-vessel coronary artery disease, and acute renal failure requiring hemodialysis. The patient was transferred from another hospital for the emergency surgery, but before his transfer, he developed HITTS secondary to therapeutic heparin for a deep vein thrombosis of the lower extremity. The presence of HITTS, the urgent nature of the case, and the availability of the direct thrombin inhibitor led the surgical team to select lepirudin for anticoagulation to facilitate cardiopulmonary bypass. After separation from cardiopulmonary bypass, the patient was in a coagulopathic state due to the inability to reverse the lepirudin and the slowed elimination of the drug secondary to inadequate renal function. As a result, the patient experienced excessive generalized oozing that was unresponsive to traditional therapies and blood product transfusions. Recombinant factor VIIa 35 microg/kg was given as rescue therapy. The bleeding slowed, which allowed placement of chest tubes and closing of the sternum. The patient was transferred to the intensive care unit in stable condition with no evidence of thrombosis in the freshly placed bypass grafts or on the bioprosthetic valve. Recombinant factor VIIa appears to be a suitable option as salvage therapy in patients with refractory bleeding secondary to anticoagulation with a direct thrombin inhibitor during cardiac surgery.

Recombinant activated factor VII and the anaesthetist

Recombinant activated factor VII is a safe and effective for the treatment and prevention of haemorrhage in haemophiliacs with circulating inhibitors to replacement factors, and patients with Glanzmann's thrombasthenia refractory to platelet transfusion. By restoring thrombin generation on the surface of tissue factor bearing cells, such as activated platelets and monocytes, recombinant activated factor VII has the potential to effect haemostasis in the setting of many coagulopathic states encountered by the anaesthetist in the operating theatre or the intensive care unit. Case reports of successful rescue therapy make up the majority of the literature covering other, numerous, off-label uses of recombinant activated factor VII, although some randomised, controlled studies, mostly underpowered to address safety concerns, have been performed. However, off-label use is becoming increasingly popular judging by the number of published case reports. Additional randomised, controlled trials to determine the safe and appropriate use of this potentially valuable therapy in broader patient groups are eagerly awaited.

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.

Clinical experiences and current evidence for therapeutic recombinant factor VIIa treatment in nontrauma settings

The hemostatic properties of recombinant activated factor VII (rFVIIa) are established in patients with inherited or acquired hemophilia with inhibitors and in patients with congenital factor VII deficiencies. Emerging clinical evidence suggests that there may be a wider role for rFVIIa in the management of hemorrhage associated with traumatic injury/accident and severe bleeding associated with critical surgery. This article considers recent data from studies in which rFVIIa was used in an attempt to control bleeding in clinical situations as diverse as coagulopathy associated with chronic liver disease, massive perioperative bleeding and bleeding during prostatectomy, organ transplantation and orthopedic surgery, uncontrollable obstetric hemorrhage, and intracerebral hemorrhage. In nontrauma settings involving acute and potentially life threatening bleeding, there may be a place for rFVIIa as adjunctive therapy in the control of hemostasis.

Evaluation of the profile of thrombin generation during the process of whole blood clotting as assessed by thrombelastography

The objective of this study was to evaluate the possibility of linking the tracing of whole blood clotting in a thrombelastograph (TEG) hemostasis system with the generation of thrombin assessed by thrombin/antithrombin complex (TAT). Citrated whole blood containing corn trypsin inhibitor from volunteers was clotted in the presence of CaCl2 and tissue factor. Clotting was monitored with the eight channels of a TEG system. At different time points, the whole blood TEG reaction cups were kept in a cold quenching solution, centrifuged, and the supernatants were kept at -80 degrees C until assayed for TAT by ELISA. The total thrombus generation (TTG) was calculated from the first derivative of the TEG waveform and was compared with thrombin generation measured by TAT. The two vector values--the TAT thrombin generation data and the corresponding TEG TTG--were analyzed using Pearson correlation coefficients (r) and linear, non-linear and natural log (ln) transformation of TAT values for least-squares goodness-of-fit curves. The best least-squares fit is an exponential curve. Linearizing using the ln of the TAT thrombin generation variable produces the same r (0.94) as of the exponential curve. The prediction equation is y = 8.0465 + 0.0005x (P < or = 0.0001), where y is the TAT thrombin generation variable in the ln transformation and x is the TEG TTG variable. The high magnitude of r and the high significance of the prediction equation demonstrate the high efficacy of the prediction of TAT thrombin generation by the use of TEG TTG.

Thoughts and Progress. Protracted Bleeding After Hirudin Anticoagulation for Cardiac Surgery in a Patient With HIT II and Chronic Renal Failure

Heparin-induced thrombocytopenia type II (HIT II) requires alternative anticoagulation. Hirudin has been effectively used in patients with HIT II scheduled for cardiac surgery. However, bleeding complications were observed in patients with renal impairment. In vitro hemodialysis (HD) has been questioned over its efficacy in eliminating hirudin. Another approach to stop bleeding is the application of recombinant factor VIIa (rFVIIa). We report on a patient with HIT II and chronic renal failure who suffered from severe hirudin-induced bleeding after cardiac surgery who was safely treated with a combined approach of surgical hemostasis, substitution of blood products, HD, and rFVIIa to stop finally bleeding.

Recombinant factor VIIa (NovoSeven) as a hemostatic agent after surgery for congenital heart disease

BACKGROUND

Postoperative bleeding and blood product requirements can be substantial in children undergoing open-heart surgery, and reexploration is required in 1% of cases. Recombinant activated factor VII (rFVIIa, NovoSeven, NovoNordisk, Denmark) is a hemostatic agent approved for the treatment of hemophilic patients with inhibitors to factor VIII or factor IX. It has also been used with success in other conditions. We present our experience with rFVIIa treatment for uncontrolled bleeding after open-heart surgery in five pediatric patients.

METHODS

The study group consisted of five patients after open-heart surgery with excessive blood loss. The patients were treated with rFVIIa after failure of conventional treatment to control the bleeding. Blood loss, blood product consumption, and coagulation test results were recorded before and after rFVIIa administration.

RESULTS

In all cases, blood loss decreased considerably after rFVIIa administration (mean 7.8 ml x kg(-1) x h(-1)), almost eliminating the need for additional blood products, and the prolonged prothrombin time normalized. In two patients with thrombocytopathy, rFVIIa helped to discriminate surgical bleeding from bleeding caused by a defect in hemostasis. No side effects of rFVIIa treatment were noted.

CONCLUSIONS

These cases support the impression that RFVIIa is efficient and safe in correcting hemostasis in children after cardiopulmonary bypass when other means fail. However, the data are still limited, and more extensive research is needed.

Recombinant factor VIIa for intractable blood loss after cardiac surgery: a propensity score-matched case-control analysis

BACKGROUND

Cardiac surgery is occasionally complicated by massive blood loss that is refractory to standard hemostatic interventions. Recombinant factor VIIa (rF-VIIa) is being increasingly used as rescue therapy in such cases, but little information is available on its safety and efficacy for this indication.

STUDY DESIGN AND METHODS

The outcomes of the first 51 cardiac surgery patients who received rF-VIIa for intractable blood loss (from November 2002 to February 2004) at a single institution according to a standardized clinical guideline were compared to 51 matched control patients, with the control patients identified from a large database and matched based on the propensity for massive blood loss.

RESULTS

Blood loss and blood product usage were significantly decreased after 2.4 to 4.8 mg of rF-VIIa. In those treated after sternal closure (n = 32), there was a significant reduction in blood loss from the hour before to the hour after treatment: 100 (70, 285) mL (median [25th, 75th percentiles]; p < 0.0001). Except for a slower postoperative recovery and higher incidence of acute renal dysfunction, the adverse event rates were similar between the rF-VIIa-treated patients and their matched controls.

CONCLUSIONS

These results suggest that rF-VIIa may be an effective rescue therapy for patients with intractable hemorrhage after cardiac surgery. A clinically important risk of stroke or other major thrombotic complications could not be ruled out by our study. Controlled clinical trials with adequate power to detect the impact of rF-VIIa therapy on morbidity and mortality therefore are necessary before one can recommend its routine use in patients undergoing cardiac surgery who have excessive bleeding.

Recombinant activated factor VII (rFVIIa) as salvage treatment for intractable hemorrhage

BACKGROUND: Recently, there has been an increased use of recombinant activated factor VII (rFVIIa) to promote hemostasis in various hemorrhagic conditions. The objective of this study was to determine the outcome of patients treated with rFVIIa who had intractable bleeding associated with cardiac surgery (CSP) or as a result of other causes (OBP). METHODS: The medical records of 40 consecutive patients treated with rFVIIa were retrospectively reviewed for blood product use before and after treatment. In all patients, rFVIIa was given only after all other measures to stop bleeding had failed. The number of transfused units of red cells (R), platelets (P), fresh frozen plasma (F), and cryoprecipitate (C) were determined both before and after administration of rFVIIa, and the results compared. Mortality at 4 hours and 30 days was assessed. Patients dying within 4 hours of rFVIIa administration were not evaluable for response. Patient characteristics were also assessed as risk factors for mortality. RESULTS: Twelve of 24 CSP survived for more than 4 hours. These 12 patients required an average of 17 units (U) of R, 18 U of P, 18 U of F and 15 U of C pre-treatment compared to an average of 6 U, 10 U, 9 U and 4 U of R, P, F and C respectively, post-treatment. These differences were statistically significant. For the OBP, 11 of 16 survived more than four hours. These 11 patients required an average of 10 U of R, 11 U of P, 14 U of F and 10 U of C pretreatment compared to an average of 1 U, 2 U, 2 U and 0 U of R, P, F, and C respectively, post-treatment. With the exception of C, there was a statistically significant decrease in blood product use following treatment with rFVIIa. Of the survivors in each group, 6 of 12 CSP and 2 of 11 OBP died between 3 and 30 days post-treatment from causes other than bleeding. Mortality at 30 days for CSP and OBP survivors was 50% and 18% respectively, whereas overall 30 day mortality was 75% for CSP and 44% for OBP. CONCLUSIONS: rFVIIa is effective in decreasing blood product use and promoting hemostasis in patients with intractable bleeding associated with cardiac surgery and a variety of other causes.

Recombinant Factor VIIa for Life-Threatening Bleeding in High-Risk Cardiac Surgery Despite Full-Dose Aprotinin

We report the case of an orthotopic heart transplant in a patient with multiple previous cardiac surgeries. The case was prolonged and complicated by severe coagulopathy and bleeding despite the use of full-dose aprotinin throughout. Bleeding was not controlled after 30 U of platelets, 20 U of fresh frozen plasma, and 10 U of cryoprecipitate. However, after the administration of recombinant factor VIIa 90 microg/kg, the rate of bleeding slowed dramatically and no further factor replacement was required. There was no evidence of unwanted clot formation within the newly transplanted heart or around the intraaortic balloon pump that remained in situ for 72 h postoperatively. With the combined risks of coagulopathy and bleeding as well as acute right ventricular failure with increases in pulmonary vascular resistance, the re-do sternotomy for heart transplant seems to be an ideal situation in which to consider the use of recombinant factor VIIa.

Modulation of endothelial cell inflammatory integrins and stress markers with rh-factor VIIa in patients with advanced chronic hepatitis C

Individuals with chronic hepatitis C (CHC) progress to cirrhosis and hepatic cancer. Individuals with advanced CHC are coagulopathic and can manifest fibrinolysis. The coagulopathy is a consequence of hepatocytic dysfunction. The fibrinolysis represents a response to local endothelial cell injury, and is of a low-grade. Based upon this hypothesis, the effect of the infusion of recombinant human factor VIIa (rh-FVIIa) on endothelial cell inflammatory integrins and measures of endothelial stress were determined in 17 individuals with advanced CHC. Immediately prior to the infusion of rh-FVIIa, the plasma levels of tissue factor (TF), Thrombomodulin (TM), human soluble ICAM-1 (hs-ICAM-1), human soluble VCAM-1 (hs-VCAM-1), human soluble L-Selectin (hs-L-Selectin), the prothrombin time and the activated partial thromboplastin time were determined. The same parameters were assayed at 5, 10, 30, 120, 240 and 360 min after infusion. TF and TM levels were very high at baseline consistent with a vascular endothelial stress response. Similarly hs-ICAM-1, hs-VCAM-1 as well as L-Selectin levels were increased. Thirty minutes after the infusion, a marked reduction in ICAM-1 and VCAM-1 and to a lesser degree L-Selectin levels was observed. This reduction persisted for 360 min. No change in measures of fibrinolysis [plasminogen activator inhibitor-1 (PAI-1), total tissue factor pathway inhibitor (t-TFPI), activated tissue factor pathway inhibitor (TFPIa), d-dimers (DD), FSP and fibrinogen levels] occurred. In addition, no change in plasma Annexin-V was observed. Based upon these data it can be concluded that: (1) rh-FVIIa corrects the coagulopathy seen in advanced CHC; (2) reduces endothelial cell injury and/or stress as evidenced by the TF, TM, hs-ICAM-1 and hs-VCAM-1 levels in plasma; (3) these changes in coagulation occurred without inducing a propagated vascular thrombosis.

Management of the patient with coagulation disorders

Understanding normal haemostasis and the pathophysiology of its disorders is essential for providing optimal care and ensuring judicious usage of blood products, as is keeping abreast of novel therapeutic modalities in a rapidly evolving field. The growing availability of synthetic coagulation factors has (at least in the western hemisphere) helped to reduce morbidity and therapeutic complications, while expanding the indications and usage of these agents. Promising advances in gene therapy may indeed introduce a sea change in the next decade or two.