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

Recombinant Activated Factor VII (rFVIIa) for Bleeding After Thoracic Aortic Surgery: A Scoping Review of Current Literature

BACKGROUND

Bleeding after surgery on the thoracic aorta is a frequent complication, and can be associated with a significant increase in morbidity and mortality. Recombinant activated factor VII (rFVIIa) was developed initially for treating patients with hemophilia; however, it has been used increasingly "off-label" to achieve hemostasis after thoracic aortic procedures.

OBJECTIVE

This scoping review aimed to present the available literature on the role of rFVIIa in the management of refractory postoperative bleeding after thoracic aortic surgery.

METHODS/RESULTS

An electronic database search was conducted using Medline, Embase, Cochrane Library, and Google Scholar in June 2023. The authors included studies that reported the use of rFVIIa in patients undergoing surgical repair of ascending or descending aortic aneurysm or dissection. Single-case reports were excluded. Ten publications with a pooled number of 649 patients (319 patients received rFVIIa and 330 in the control groups) were identified: 3 case series, 6 retrospective studies, and 1 nonrandomized clinical trial. All studies reported the potential role of rFVIIa in correcting coagulopathy and reducing postoperative blood loss in this group of patients. Overall, there was not enough evidence to suggest that rFVIIa was associated with higher rates of thromboembolic complications or mortality.

CONCLUSION

Limited evidence suggests that rFVIIa may be useful in managing postoperative refractory bleeding in patients undergoing thoracic aortic surgery. However, the impact of rFVIIa on thromboembolic complications and mortality rates remains unclear.

Factor VIIa administration in orthotopic heart transplant recipients and its impact on thromboembolic events and post-transplant outcomes

Recombinant, activated factor VIIa (rFVIIa) is used during cardiac surgeries to mitigate refractory coagulopathic bleeding. The purpose of this study was to examine whether rFVIIa use in orthotopic heart transplant (OHT) recipients was associated with a higher incidence of thromboembolic (TE) events compared to patients who did not. A single-center, retrospective, cohort study was performed on OHT recipients who received rFVIIa for refractory coagulopathic bleeding from January 2013 to December 2015. Patients were evaluated for up to 6 months after transplantation and assessed for TE events, rejection, readmissions, graft survival, and patient survival. Categorical variables were analyzed using the Chi square test while student's t or ANOVA testing was utilized for continuous variables. Of the 62 patients who met inclusion criteria, 27 patients received rFVIIa, and 35 patients were selected for the control group. The overall incidence of TE events was not significantly different between patients who received rFVIIa compared to patients in the control group (14.8% vs 11.4%) (p = 0.69). Within 14 days, 14.81% of rFVIIa patients suffered a TE event compared to 5.7% of the control group (p = 0.23). Rejection, readmissions, graft survival, and patient survival were not significantly different at any time points. Use of rFVIIa in heart transplantation showed no difference in the overall rate of TE events, however, there was a nonsignificant trend toward higher risk of early TE development in the rFVIIa group compared to the control group.

Combination use of platelets and recombinant activated factor VII for increased hemostasis during acute type a dissection operations

Background

Refractory blood loss is a common problem in surgeries for acute type A aortic dissections. Significant evidence has supported the benefit of using recombinant activated factor VII (rFVIIa) to control of intractable bleeding in patients after cardiac surgery. In this prospective clinical study, we present a novel method to achieve intraoperative hemostasis by using a combination of platelets and rFVIIa during operations for acute type A aortic dissections.

Methods

Between May 2009 and August 2012, 71 patients with acute type A dissections who underwent emergency surgery were prospectively included and allocated to one of the following two intervention groups for hemostasis: 3 units platelets combined with 2.4 mg rFVIIa (n = 25), and conventional methods (n = 46).

Results

The patients who received the combination of platelets and rFVIIa required fewer transfusions of red blood cells (6.2 ± 3.1 units vs 9.8 ± 2.8 units; p < 0.05), fresh frozen plasma (736.9 ± 178.3 ml vs 1264.3 ± 245.2 ml, p < 0.05), platelet concentrates (3 units vs 5.0 ± 1.8 units, p < 0.001), and cryoprecipitate (2.8 ± 0.9 units vs 8.2 ± 2.3 units, p < 0.05). These patients also required less time for sternal closure (76.9 ± 17.2 min vs 102.3 ± 10.7 min, p < 0.05) compared with the conventional therapy patients. There was no statistically significant difference in the incidence of serious adverse events between these two groups.

Conclusions

Using a combination of platelets and rFVIIa is an effective strategy for achieving hemostasis during acute type A dissection surgery. This hemostatic strategy does not appear to be associated with an increase in postoperative adverse events.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0156-y) contains supplementary material, which is available to authorized users.

The hemostatic profile of recombinant activated factor VII. Can low concentrations stop bleeding in off-label indications?

BACKGROUND

High concentrations of recombinant activated factor VII (rFVIIa) can stop bleeding in hemophilic patients. However the rFVIIa dose needed for stopping haemhorrage in off-label indications is unknown. Since thrombin is the main hemostatic agent, this study investigated the effect of rFVIIa and tissue factor (TF) on thrombin generation (TG) in vitro.

METHODS

Lag time (LT), time to peak (TTP), peak TG (PTG), and area under the curve after 35 min (AUCo-35 min) with the calibrated automated thrombography was used to evaluate TG. TG was assayed in platelet-rich plasma (PRP) samples from 29 healthy volunteers under basal conditions and after platelet stimulation with 5.0 mug/ml, 2.6 mug/ml, 0.5 mug/ml, 0.25 mug/ml, and 0.125 mug/ml rFVIIa alone and in normal platelet-poor plasma (PPP) samples from 22 healthy volunteers, rFVIIa in combination with various concentrations of TF (5.0, 2.5, 1.25 and 0.5 pM).

RESULTS

In PRP activated by rFVIIa, there was a statistically significant increase in TG compared to basal values. A significant TF dose-dependent shortening of LT and increased PTG and AUCo-->35 min were obtained in PPP. The addition of rFVIIa increased the effect of TF in shorting the LT and increasing the AUCo-->35 min with no effect on PTG but were independent of rFVIIa concentration.

CONCLUSION

Low concentrations of rFVIIa were sufficient to form enough thrombin in normal PRP or in PPP when combined with TF, and suggest low concentrations for normalizing hemostasis in off-label indications.

Use of rFVIIa for critical bleeding in cardiac surgery: dose variation and patient outcomes

BACKGROUND AND OBJECTIVES

Recombinant activated factor VIIa (rFVIIa) is increasingly being used in non-haemophiliac patients for the treatment of severe bleeding refractory to standard interventions. Optimal dosing regimens remain debated in cardiac surgery. Therefore, this study investigated the use of different rFVIIa dosing practices on response to bleeding and patient outcomes in cardiac surgery patients using data from the Haemostasis Registry.

METHODS

Data were extracted from the Haemostasis Registry that records cases of off-licence rFVIIa use in participating institutions. Univariate analyses compared patients receiving < or =40 microg/kg, 41-60 microg/kg, 61-80 microg/kg, 81-100 microg/kg and >100 microg/kg of rFVIIa on key parameters. Logistic regression models investigated the relationship between independent variables and 28-day mortality.

RESULTS

Complete data was available on 804 cardiac surgery patients who received rFVIIa. Of these, 42 (5.2%) were treated with doses < or =40 microg/kg, while the dose group containing the most patients was 81-100 microg/kg (368, 45.77%). Results demonstrated no significant differences in the rate of thromboembolic adverse events, response to bleeding or 28-day mortality.

CONCLUSIONS

These findings raise the important question of whether lower doses of rFVIIa may be as effective as higher doses in the treatment of severe bleeding in cardiac surgery patients.

Variation in the use of recombinant activated factor VII in critical bleeding

BACKGROUND

Recombinant activated factor VII (rFVIIa) is being increasingly used as a treatment option in settings of uncontrolled bleeding. Despite this, national practice guidelines are lacking, resulting in widespread practice variation between providers. This investigation aimed to describe the differences in use of rFVIIa across Australian and New Zealand hospitals.

METHODS

Data were extracted from the Haemostasis Registry that collects both contemporaneous and retrospective cases of off-licence (i.e. in non-haemophilia patients) rFVIIa use in participating institutions. Hospitals were classified according to geographical location and service provision.

RESULTS

2075 cases from 87 hospitals were recorded on the Haemostasis Registry. Across all hospital categories, over 41% of cases received rFVIIa in relation to cardiac surgery. Case complexity varied between providers, with large urban centres treating more severely ill patients. This was reflected in significant differences in the use of blood components and products before rFVIIa administration. Despite differences in patient complexity and use of blood products between hospital categories, response to treatment and patient outcomes remained similar across providers, with survival rates ranging from 68.29% to 70.41%.

CONCLUSION

This is the largest study of off-licence use of rFVIIa. There is significant regional variation in the administration of rFVIIa in Australian and New Zealand hospitals, with little documentation of adherence to guidelines. National consensus guidelines based on available evidence should be developed and promulgated to ensure optimal outcomes.

Pediatric off-label use of recombinant factor VIIa

OBJECTIVE

Our goal was to report our institutional experience with recombinant factor VIIa for the treatment and/or prevention of bleeding in nonhemophiliac children.

METHODS

This was a retrospective case series in a tertiary pediatric referral hospital.

RESULTS

During 1999-2006, 135 patients received recombinant factor VIIa for off-label use. The median number of doses was 2; the median dose was 88 mug/kg. The most common diagnoses among patients receiving recombinant factor VIIa were disseminated intravascular coagulation/sepsis (28), surgical bleeding (19), procedural prophylaxis (16), and trauma (15). The median volume of blood products administered 24 hours before recombinant factor VIIa treatment was 29.7 vs 11.7 mL/kg 24 hours after treatment. Only 1 high-risk patient had significant bleeding after receiving prophylactic recombinant factor VIIa before an invasive procedure. Nonsurvivors had significantly increased incidence of multiple organ dysfunction syndrome (75%) compared with survivors (23%). The largest group of patients (n = 28) received recombinant factor VIIa for bleeding and/or coagulopathy because of disseminated intravascular coagulation; the mortality in this group was 26 (93%) of 28. Eleven patients received multiple doses of recombinant factor VIIa to treat bleeding complications after hematopoietic stem cell transplant, without improvement in blood use. Mortality in medical patients was 58% vs 16% in surgical patients. Three patients had significant thrombotic adverse events after receiving recombinant factor VIIa, resulting in 2 deaths and 1 leg amputation.

CONCLUSIONS

Off-label use of recombinant factor VIIa significantly decreases blood-product administration; surgical patients had control of life-threatening bleeding with low associated mortality. Prophylactic recombinant factor VIIa may be effective in preventing bleeding if given before invasive procedures in children at high risk. Prolonged use of recombinant factor VIIa for bleeding complications after hematopoietic stem cell transplant is not effective in preventing packed red blood cell transfusion. Presence of disseminated intravascular coagulation and mulitorgan dysfunction syndrome may help predict futility of recombinant factor VIIa treatment. Off-label use of recombinant factor VIIa is associated with thromboembolic events in children.

Formulary management of recombinant factor VIIa at an academic medical center

BACKGROUND

Recombinant human coagulation factor VIIa (rVIIa) is a procoagulant indicated for treatment of bleeding in patients with hemophilia. A large proportion of rVIIa utilization is for off-label administration in nonhemophiliac patients with acute hemorrhage. Concerns of potentially inappropriate use, safety, and cost of rVIIa led to efforts to standardize use of this agent.

OBJECTIVE

To comparatively describe the utilization of rVIIa upon implementation of an evidence-based guideline at a university hospital.

METHODS

With advisory direction from a multidisciplinary task force, an evidence-based guideline for use of rVIIa was developed, approved, and fully implemented. Assessment of appropriateness of use and retrospective review were required for all cases. Effects of these actions were evaluated by auditing and comparing rVIIa use in patients treated in two 6-month observation periods before and after guideline implementation. Outcomes assessed were proportions of patients deemed appropriate to receive rVIIa, compliance with dosing recommendations, and acquisition costs.

RESULTS

Twenty-two and 29 patients were treated in the periods before and after guideline implementation, respectively. Patient characteristics were similar, except more cardiothoracic surgeries were performed in patients treated before implementation of the guideline. Indications for rVIIa use were judged appropriate in 21 (95.5%) before-cases and in all (100%) after-cases. The dose was compliant in 1 (4.6%) before-case and 27 (93.1%) after-cases (p < 0.001). Mean dosages of rVIIa administered were 81.8 microg/kg and 45.3 microg/kg in before- and after-cases, respectively (p < 0.001). During the respective periods of observation, amounts of rVIIa purchased monthly averaged 42.6 mg and 21.8 mg, a 49% difference. Semiannual expenditures for rVIIa decreased approximately $110,000 following guideline implementation. Patient outcomes were similar.

CONCLUSIONS

A guideline based on currently available evidence can serve to sustain the clinical appropriateness of rVIIa therapy and substantially decrease costs.