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

Trends in the Use of Recombinant Activated Factor VII and Prothrombin Complex Concentrate in Heart Transplant Patients in Virginia

OBJECTIVES

To explore trends in intraoperative procoagulant factor concentrate use in patients undergoing heart transplantation (HTx) in Virginia. Secondarily, to evaluate their association with postoperative thrombosis.

DESIGN

Patients who underwent HTx were identified using a statewide database. Trends in off-label recombinant activated factor VII (rFVIIa) use and on-label and off-label prothrombin complex concentrate (PCC) use were tested using the Mantel-Haenszel test. Multivariate logistic regression was used to test for an association between procoagulant factor concentrate administration and thrombosis.

SETTING

Virginia hospitals performing HTx.

PARTICIPANTS

Adults undergoing HTx between 2012 and 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 899 patients who required HTx, 100 (11.1%) received off-label rFVIIa, 69 (7.7%) received on-label PCC, and 80 (8.9%) received off-label PCC. There was a downward trend in the use of rFVIIa over the 10-year period (p = 0.04). There was no trend in on-label PCC use (p = 0.12); however, there was an increase in off-label PCC use (p < 0.001). Patients who received rFVIIa were transfused more and had longer cardiopulmonary bypass time (p < 0.001). Receipt of rFVIIa was associated with increased thrombotic risk (odds ratio [OR] 1.92; 95% CI 1.12-3.29; p = 0.02), whereas on-label and off-label PCC use had no association with thrombosis (OR 0.98, 95% CI 0.49-1.96, p = 0.96 for on-label use; and OR 0.61, 95% CI 0.29-1.30, p = 0.20 for off-label use).

CONCLUSIONS

Use of rFVIIa in HTx decreased over the past decade, whereas off-label PCC use increased. Receipt of rFVIIa was associated with thrombosis; however, patients who received rFVIIa were more severely ill, and risk adjustment may have been incomplete.

rFVIIa in trauma: a review and opinion-based guidelines

Recombinant activated factor seven (rFVIIa) is a novel and emerging therapy for the acquired coagulopathy associated with massive bleeding and hemorrhagic shock. The intent of this paper is to review the mechanism of action of rFVIIa, to discuss the current state of evidence regarding the safety and efficacy of rFVIIa, and to offer guidance regarding its use in severely traumatized patients. No study has demonstrated a survival benefit in humans. rFVIIa, is safe to use in the setting of severe trauma associated with ongoing bleeding and acquired coagulopathy. Doses of 80—200 μg/kg may be used after correction of thrombocytopenia and acidosis. Hypothermia should be corrected in any traumatized patient, but should not be a barrier to its administration. Definitive evidence supporting the use of rFVIIa is lacking, but ongoing studies will delineate survival benefits, dosing regimens, and adverse events associated with its use.

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

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

Recombinant factor VII is associated with worse survival in complex cardiac surgical patients

BACKGROUND

Recombinant activated factor VII (rFVIIa) decreases requirements for allogeneic blood transfusion and chest reexploration in patients undergoing cardiac surgery. Whether rFVIIa increases the risk of postoperative adverse events is unclear. We tested whether rFVIIa administration was associated with increased mortality and neurologic and renal morbidity in patients undergoing cardiac surgery. Risk of thromboembolic complications and the dose-response of rFVIIa on mortality and morbidity were also evaluated.

METHODS

Of 27,977 patients who had complex cardiac surgery, 164 patients (0.59%) received rFVIIa perioperatively. Using propensity-matching techniques, patients were matched to a maximum of 3 control patients. Patients who received rFVIIa were compared with control patients on risk of mortality, neurologic and renal morbidity, and thromboembolic complications, including a composite of myocardial infarction, pulmonary embolism, and deep venous thrombosis. A corresponding dose-response analysis using multivariable logistic regression was also performed.

RESULTS

Propensity techniques successfully matched 144 patients (88%) with 359 control patients. Of patients who received rFVIIa, 40% experienced in-hospital mortality compared with 18% of control patients (odds ratio, 2.82; 98.3% confidence interval, 1.64 to 4.87; p<0.001). Furthermore, 31% of patients treated with rFVIIa versus 17% of control patients experienced renal morbidity (odds ratio, 2.07; 98.3% confidence interval, 1.19 to 3.62; p=0.002); however, neurologic morbidity and thromboembolic complications were not different among groups. High-dose rFVIIa (>60 μg/kg) did not increase the risk for mortality compared with treatment with low-dose rFVIIa (<60 μg/kg).

CONCLUSIONS

Administration of rFVIIa is associated with increased mortality and renal morbidity in patients undergoing cardiac surgery.

Off-label use of recombinant factor VIIa in pediatric patients

OBJECTIVE

To examine off-label recombinant factor VIIa (rFVIIa) use in pediatric patients including clinical indications, dose, adverse events, and outcomes.

METHODS

All pediatric patients entered into the Haemostasis Registry from 75 participating hospitals were analyzed.

RESULTS

Three hundred and eighty-eight pediatric patients received off-label rFVIIa from 2003 to 2009. Median age was 12 months (interquartile range 1 month to 11 years). Clinical context included cardiac surgery (52.1%), medical (11.6%), other surgery (10.8%), hematology/oncology (10.3%), trauma (9.3%), intracranial hemorrhage (3.1%), and liver disease (2.8%). Twenty-six patients received extracorporeal membrane oxygenation at the time of rFVIIa administration. Median first dose was 114 μg/kg (interquartile range 90-181; range 7-2250). Thirty-four percent received >1 dose. There was a reduction in usage of red blood cells, platelets, fresh-frozen plasma, and cryoprecipitate in the 24 hours after the first dose for all patients (all P values < .001). Thromboembolic adverse events (TEAs) were reported in 5.4%. No association between TEA and size of first dose was found. Where data were available, 82% of patients were subjectively classified as responding to rFVIIa. Overall 28-day mortality was 27%. In multivariate analysis, pH values before administration and clinical context were independently associated with response to first dose and 28-day mortality.

CONCLUSIONS

There was a significant reduction in blood product administration after rFVIIa and a subjective response rate of 82%. Both pH and clinical context were associated with response to rFVIIa and mortality. Overall, 5.4% had a TEA reported.

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.

Fresh frozen plasma and recombinant factor VIIa use in neonates

BACKGROUND

Little recent data are available describing fresh frozen plasma (FFP) use in neonates. The purpose of this study was to determine the outcomes of FFP transfusions in neonates.

PATIENTS AND METHODS

A single institution, observational, and retrospective review of each transfusion of FFP given to neonates admitted to a neonatal intensive care unit over a 2-year period.

RESULTS

One hundred and seventy-three neonates were identified as having received FFP, giving a prevalence of FFP use at 12%. By far the most common determining factor for FFP use was an association with an abnormal activated partial thromboplastin time or prothrombin time (52%). Other factors included bleeding, invasive procedures, volume expansion, necrotizing enterocolitis, cardiopulmonary bypass, and hydrops fetalis. Of objectively accessible responses, FFP was able to correct abnormal coagulation tests into the normal range only 40% of the time. Twenty-four neonates received recombinant factor VIIa (rFVIIa) after first receiving FFP. The prevalence of thrombotic events was not higher in neonates receiving rFVIIa than those receiving FFP alone.

CONCLUSIONS

FFP was widely used in this neonatal unit. As data showing the predictive value of coagulation tests in neonates are discrepant, it is unclear if FFP was being appropriately used. Prospective, controlled data are required.

Thromboelastography as a better indicator of hypercoagulable state after injury than prothrombin time or activated partial thromboplastin time

OBJECTIVES

To investigate the hemostatic status of critically ill, nonbleeding trauma patients. We hypothesized that a hypercoagulable state exists in patients early after severe injury and that the pattern of clotting and fibrinolysis are similar between burned and nonburn trauma patients.

MATERIALS

Patients admitted to the surgical or burn intensive care unit within 24 hours after injury were enrolled. Blood samples were drawn on days 0 through 7. Laboratory tests included prothrombin time (PT), activated partial thromboplastin time (aPTT), levels of activated factor XI, D-dimer, protein C percent activity, antithrombin III percent activity, and thromboelastography (TEG).

RESULTS

Study subjects were enrolled from April 1, 2004, to May 31, 2005, and included nonburn trauma patients (n = 33), burned patients (n = 25), and healthy (control) subjects (n = 20). Despite aggressive thromboprophylaxis, three subjects (2 burned and 1 nonburn trauma patients [6%]) had pulmonary embolism during hospitalization. Compared with controls, all patients had prolonged PT and aPTT (p < 0.05). The rate of clot formation (alpha angle) and maximal clot strength were higher for patients compared with those of controls (p < 0.05), indicating a hypercoagulable state. Injured patients also had lower protein C and antithrombin III percent activities and higher fibrinogen levels (p < 0.05 for all). Activated factor XI was elevated in 38% of patients (control subjects had undetectable levels).

DISCUSSION

Thromboelastography analysis of whole blood showed that patients were in a hypercoagulable state; this was not detected by plasma PT or aPTT. The high incidence of pulmonary embolism indicated that our current prophylaxis regimen could be improved.

Hemostatic therapy for the treatment of intracranial hemorrhage

Intracranial hemorrhage results in poor neurologic outcomes and high mortality. Current management is limited to supportive care. In addition to the initial bleeding event, rebleeding and hematoma expansion have been identified as major risk factors for poor outcomes in these patients. The antifibrinolytic agents tranexamic acid, aminocaproic acid, and recombinant activated factor VII (rFVIIa) have been studied with the hopes of achieving early hemostasis and improving outcomes. Available data suggest that tranexamic acid and aminocaproic acid are more harmful than beneficial for this indication; therefore, they have no role in the treatment of intracranial bleeding. Alternatively, rFVIIa, has shown promising results in the management of spontaneous intracerebral hemorrhage. Clinicians should be aware of the available evidence regarding the use of these hemostatic agents in the management of intracranial hemorrhage, including traumatic brain injury, intracerebral hemorrhage, and subarachnoid hemorrhage.

Failure of recombinant factor VIIa in a patient with severe polymicrobial sepsis and postoperative uncontrolled intraabdominal bleeding

Background

This report discusses a case of unsuccessful treatment with recombinant factor VIIa (rFVIIa) in off-label use. The need for international guidelines concerning the off-label use of rFVIIa is outlined as well as the need for methods to control the efficacy of rFVIIa objectively.

Case presentation

54 year old male with severe polymicrobial sepsis due to a perforated diverticulitis of the sigmoid colon and consecutive overt disseminated intravascular coagulation. He suffered severe intraabdominal bleeding after abdominal surgery despite conventional haemostatic support. Repeated applications of factor VIIa temporarily improved coagulation essays but did not stop clinical bleeding. The patient died in multiorgan failure due to septic and haemorrhagic shock.

Conclusion

Off-label use of rFVIIa could result in more side effects than could be expected from literature because of a publication bias. However for most off-label applications large prospective, randomised and controlled trials to confirm the positive findings are missing. For the future, not only guidelines concerning the off-label use of rFVIIa are urgently needed but also guidelines for monitoring the efficacy of rFVIIa.

Pharmacology and clinical use of recombinant activated factor seven in neurosciences

Recombinant activated factor VII (rFVIIa, NovoSeven, NovoNordisc, Danemark) has been approved for the treatment of patients with hemophilia with inhibitors, further indications, at least in some countries, include the treatment of factor VII deficiency and Glanzmann thrombasthenia refractory to conventional therapy. Apart from these indications, the agent is increasingly used for the treatment of severe and potentially life-threatening bleeding manifestations, irrespective of the underlying hemostatic abnormality. The agent has successfully been used for the treatment of both inherited and acquired coagulopathies as well as thrombocytopathia or thrombocytopenia, however, most information on off-label use derives from case reports and retrospective studies and therefore publication bias can-not be excluded. In this review, we focus on the use of rFVIIa for the treatment of spontaneous and perioperative intracranial hemorrhage as well as trauma patients. We review the current knowledge regarding the physiology of hemostasis, the pharmacology of rFVIIa, and its clinical use in neurosciences. Further studies are urgently needed to define the efficacy and safety of recombinant activated factor VII in patients without hemophilia, factor VII deficiency, or Glanzmann thrombasthenia. At time, its use can be justified in life-threatening bleeding situations refractory to conventional treatment.

Prophylactic recombinant factor VIIa administration to an infant with congenital systemic juvenile xanthogranuloma

We report the case of an infant affected with congenital systemic juvenile xanthogranuloma scheduled for central venous access system implantation (Port-a-Cath) and a liver and bone marrow biopsy. The patient had impaired liver function, thrombocytopenia, and coagulopathy which was refractory to daily fresh-frozen plasma and platelet infusions: 80 microg x kg(-1) dose(-1) of recombinant factor VIIa (rFVIIa) was administered i.v. every 2 h starting 30 min before the procedure and ending 6 h afterwards. Very minor bleeding was observed during the procedure. In conclusion, rFVIIa therapy was effective as prophylaxis for both invasive procedures in this patient with a coagulopathy which was refractory to other different therapies.