Recombinant factor VIIa (NovoSeven RT) use in high risk cardiac surgery

Comparison of low- and high-dose recombinant activated factor VII for postcardiac surgical bleeding

Aim of the Study:

A retrospective observational study to compare safety and efficacy of high and low doses of recombinant activated factor VIIa (rFVIIa) in severe postcardiac surgical bleeding.

Patients and Methods:

From 2004 to 2014, all patients who received rFVIIa for bleeding after cardiac surgery were included and arranged in two groups; Group 1: Low dose (40–50 mcg/kg) (n = 98) and Group 2: High dose (90–120 mcg/kg) (n = 156).

Results:

There was no significant difference in demographic and surgical characteristics of both groups on admission to Cardiac Surgical Intensive Care Unit (CSICU). There was no significant difference between the two groups regarding the reduction in chest tube bleeding in the first 6 h or the transfusion requirement in the 24 h after admission to CSICU. A total of 15 patients (5.9%) had thromboembolic adverse events. (Seven (7.1%) patients in Group 1 compared to 8 (5.1%) patients in Group 2, P = 0.58). There were no significant differences in all-cause mortality at 30 days (2% in Group 1 vs. 3.2% in Group 2, P = 0.6) and at hospital discharge between the two study groups (6.1% in Group 1 vs. 8.3% in Group 2, P = 0.5), respectively. There was no significant difference between the two groups regarding the need for re-exploration, days on mechanical ventilation, CSICU, or hospital stay.

Conclusion:

In this report, Low-dose rFVIIa showed equivalent efficacy and safety to high-dose rFVIIa. Further prospective randomized studies are needed to confirm these findings.

Recombinant Activated Factor VII Significantly Reduces Transfusion Requirements in Cardiothoracic Surgery

Background

The off-label use of recombinant activated factor VII (rFVIIa) for intractable bleeding is associated with a risk of thrombotic events. The objective of this study was to evaluate the incidence and predictors of rFVIIa-related thrombotic events and its efficacy in the reduction of transfusion requirements during various surgeries.

Methods

Ninety-two cases received rFVIIa for uncontrollable bleeding despite medical and surgical hemostasis. The incidence and risk factors of thrombotic events were analyzed. Blood products transfused in the 24 h before and after rFVIIa injection were calculated. Subgroup analysis was performed to see which types of surgeries benefited most from rFVIIa.

Results

The main indication for rFVIIa administration was uncontrollable bleeding during cardiothoracic surgery followed by coagulopathy due to liver failure followed by neurosurgical procedures. Requirements of blood products after rFVIIa decreased significantly by 45 % (p = 0.012), 52 % (p = 0.0001), and 75 % (p = 0.0001) for red blood cells, plasma, and cryoprecipitate, respectively. Subgroup analysis showed that cardiothoracic surgery was the sole group that benefited from rFVIIa with a reduction in transfusion of red blood cells (p = 0.013), plasma (p = 0.0001), and cryoprecipitate (p = 0.0001). Thrombotic events occurred in 9.8 % of the cases mostly on the arterial side (89 %) and have not contributed to mortality.

Conclusion

rFVIIa can significantly reduce transfusion requirements when given for intractable bleeding during cardiothoracic surgery at the expense of thrombotic events in approximately one tenth of the cases. Further prospective studies are necessary to study if this effect of rFVIIa is translated to a favorable outcome.

Electronic supplementary material

The online version of this article (doi:10.1007/s40268-015-0093-9) contains supplementary material, which is available to authorized users.

Correcting thrombin generation ex vivo using different haemostatic agents following cardiac surgery requiring the use of cardiopulmonary bypass

Recently, lower thrombin generation has been associated with excess bleeding post-cardiopulmonary bypass (CPB). Therefore, treatment to correct thrombin generation is a potentially important aspect of management of bleeding in this group of patients. The objective of the present study was to investigate the effects of fresh frozen plasma (FFP), recombinant factor VIIa (rFVIIa), prothrombin complex concentrate (PCC) and tissue factor pathway inhibitor (TFPI) inhibition on thrombin generation when added ex vivo to the plasma of patients who had undergone cardiac surgery requiring CPB. Patients undergoing elective cardiac surgery were recruited. Blood samples were collected before administration of heparin and 30 min after its reversal. Thrombin generation was measured in the presence and absence of different concentrations of FFP, rFVIIa, PCC and an anti-TFPI antibody. A total of 102 patients were recruited. Thrombin generation following CPB was lower compared with pre-CPB (median endogenous thrombin potential pre-CPB 339 nmol/l per min, post-CPB 155 nmol/l per min, P < 0.0001; median peak thrombin pre-CPB 35 nmol/l, post-CPB 11 nmol/l, P < 0.0001). Coagulation factors and anticoagulants decreased, apart from total TFPI, which increased (55-111 ng/ml, P < 0.0001), and VWF (144-170 IU/dl, P < 0.0001). Thrombin generation was corrected to pre-CPB levels by the equivalent of 15 ml/kg FFP, 45 μg/kg rFVIIa and 25 U/kg of PCC. Inhibition of TFPI resulted in an enhancement of thrombin generation significantly beyond pre-CPB levels. This study shows that FFP, rFVIIa, PCC and inhibition of TFPI correct thrombin generation in the plasma of patients who have undergone surgery requiring CPB. Inhibition of TFPI may be a further potential therapeutic strategy for managing bleeding in this group of patients.

The Effect of Intravenous Administration of Active Recombinant Factor VII on Postoperative Bleeding in Cardiac Valve Reoperations; A Randomized Clinical Trial

BACKGROUND

Postoperative bleeding after cardiac reoperations is among the most complicating problems, both for the physicians and for the patients. Many modalities have been used to decrease its adverse effects and the need for blood products administration.

OBJECTIVES

In a randomized double-blinded clinical trial of redo cardiac valve surgery in adult, the effect of active recombinant factor VII (rFVIIa) on postoperative bleeding was compared with placebo. Chest tube drainage was used for comparison of bleeding between the two groups.

PATIENTS AND METHODS

Two groups of 18 patients undergoing redo valve surgeries were treated and compared regarding chest tube drainage, need for blood products, prothrombin time (PT), partial thromboplastin time (PTT), hemoglobin and hematocrit, platelet count, and international normalized ratio (INR) in first 24 hours after surgery. Bleeding was assessed at 3rd, 12th, and 24th hour after operation. In rFVIIa group, 40 µg/kg of AryoSeven was administered before end of surgery and same volume of normal saline was administered as placebo in the control group.

RESULTS

Study groups showed no difference regarding baseline variables. Three patients in rFVIIa group (16.67%) and 13 in placebo group (72.23%) received blood products (P < 0.01). Chest tube blood drainage at 24th hour after operation was 315 ± 177 mL in rFVIIa group and 557 ± 168 mL in control group (P = 0.03). At third and 12th hour after operation, the difference was not statistically significant (P = 0.71 and P = 0.22, respectively). Postoperative ICU stay was not different; while extubation was longer in the placebo group (352 ± 57 vs. 287 ± 46 minutes; P = 0.003).

CONCLUSIONS

Our study demonstrated the efficacy of rFVIIa in controlling postoperative bleeding in redo cardiac valve surgeries regarding subsequent blood loss and transfusion requirement; however, outcome results remains to be defined.

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.

Intraoperative use of low-dose recombinant activated factor VII during thoracic aortic operations

BACKGROUND

Numerous studies have supported the effectiveness of recombinant activated factor VII (rFVIIa) for the control of bleeding after cardiac procedures; however safety concerns persist. Here we report the novel use of intraoperative low-dose rFVIIa in thoracic aortic operations, a strategy intended to improve safety by minimizing rFVIIa exposure.

METHODS

Between July 2005 and December 2010, 425 consecutive patients at a single referral center underwent thoracic aortic operations with cardiopulmonary bypass (CPB); 77 of these patients received intraoperative low-dose rFVIIa (≤60 μg/kg) for severe coagulopathy after CPB. Propensity matching produced a cohort of 88 patients (44 received intraoperative low-dose rFVIIa and 44 controls) for comparison.

RESULTS

Matched patients receiving intraoperative low-dose rFVIIa got an initial median dose of 32 μg/kg (interquartile range [IQR], 16-43 μg/kg) rFVIIa given 51 minutes (42-67 minutes) after separation from CPB. Patients receiving intraoperative low-dose rFVIIa demonstrated improved postoperative coagulation measurements (partial thromboplastin time 28.6 versus 31.5 seconds; p=0.05; international normalized ratio, 0.8 versus 1.2; p<0.0001) and received 50% fewer postoperative blood product transfusions (2.5 versus 5.0 units; p=0.05) compared with control patients. No patient receiving intraoperative low-dose rFVIIa required postoperative rFVIIa administration or reexploration for bleeding. Rates of stroke, thromboembolism, myocardial infarction, and other adverse events were equivalent between groups.

CONCLUSIONS

Intraoperative low-dose rFVIIa led to improved postoperative hemostasis with no apparent increase in adverse events. Intraoperative rFVIIa administration in appropriately selected patients may correct coagulopathy early in the course of refractory blood loss and lead to improved safety through the use of smaller rFVIIa doses. Appropriately powered randomized studies are necessary to confirm the safety and efficacy of this approach.