High-Dose Recombinant Factor VIIa Therapy in Hemophilia Patients With Inhibitors

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.

High incidence of thromboembolic events in left ventricular assist device patients treated with recombinant activated factor VII

BACKGROUND

Dosing of recombinant activated factor VII (rFVIIa) is controversial and unstandardized, and there is growing concern about thromboembolic complications, especially in left ventricular assist device (LVAD)-supported patients. We reviewed our experience with rFVIIa administration in patients with LVADs and examined its effectiveness and adverse effects, including the incidence of thromboembolic events and its correlation with increasing doses.

METHODS

We retrospectively reviewed the records of 62 patients who received an LVAD and rFVIIa at our center between January 2004 and November 2006. Patients who received a single dose of 10 to 20 microg/kg (n = 32; 52%) constituted the "low-dose" cohort, and patients who received 30 to 70 microg/kg (n = 30; 48%) constituted the "high-dose" cohort. Laboratory values obtained before and after rFVIIa administration, as well as patients' transfusion requirements, were compared to determine the effectiveness of rFVIIa in reversing coagulopathy and reducing blood loss. We also compared the incidence of thromboembolic events in the low- and high-dose groups.

RESULTS

Administration of rFVIIa was associated with significant decreases in prothrombin time, activated partial thromboplastin time and transfusion requirements. This association was seen in both the low- and high-dose groups. In addition, the incidence of thromboembolic events was significantly higher in the high-dose group (36.7%) than in the low-dose group (9.4%) (p < or = 0.001).

CONCLUSIONS

Although rFVIIa administration seemed helpful in controlling life-threatening hemorrhage, patients requiring higher doses (30 to 70 microg/kg) had a dramatically higher incidence of serious thromboembolic events.

An overview of the history, clinical practice concerns, comparative studies and strategies to optimize therapy of bypassing agents

Despite significant advances in the treatment of haemophilia, including availability of recombinant coagulation factor replacement products and the use of prophylactic infusion regimens, the segment of haemophilic patients who develop inhibitory antibodies remain at higher risk for morbidity and mortality associated with recurrent or uncontrolled bleeding events. Bypassing agents represent the mainstay of treatment and prevention of bleeding. The most commonly used of the currently available therapeutic agents are a plasma-based therapy, factor eight inhibitor bypassing activity, vapour heated, and a recombinant therapy, NovoSeven (recombinant activated factor VIIa). A substantial body of literature exists to document efficacy and adverse event profiles for these two products. There is, however, a paucity of data arising from adequately powered prospective trials to determine optimal treatment and dosing in various clinical situations. Certain clinical circumstances, patient profiles, individual responses, or provider predilection may lead to preferential use of one of these products over the other; however, the continued presence of both agents in the therapeutic armamentarium remains critically important to this fragile population. The historical use, clinical practice concerns, published comparative studies and methods for optimization of these two bypassing agents are reviewed.

Rescue treatment with recombinant factor VIIa is effective in patients with life-threatening bleedings secondary to major wound excision: a report of four cases

Major burn wound excision is associated with excessive perioperative blood loss. Treatment of massive microvascular bleeding represents a special problem in the burn setting, characterized by extensive damage at the capillary level, and resulting in a profound blood loss; which together with the consumptive states makes adequate replacement therapy with coagulation factors and platelets difficult. We described our experience with rescue treatment with rFVIIa in four patients undergoing major wound excision, developing life-threatening perioperative bleeding, and not responding to conventional therapy. Hemostasis was achieved within 15 minutes of intravenous rFVIIa administration, at a dose of 100 microg/kg, in all patients. No treatment-related adverse events, in particular, no thromboembolic events were observed. We conclude that rFVIIa may be an effective hemostatic treatment for patients undergoing major wound excision developing life-threatening bleedings.