Heart transplant in a factor VIII-deficient patient with a high-titre inhibitor: perioperative management using high-dose continuous infusion factor VIII and recombinant factor VIIa

In vitro effects of emicizumab on activated clotting time in blood samples from cardiac surgical patients

BACKGROUND

Heparin management in hemophilia A (HA) patients with a factor VIII (FVIII) inhibitor can be challenging due to severe activated clotting time (ACT) prolongations. It is important to better understand the impact of emicizumab, a FVIII mimetic on ACT, and tissue factor (TF)-based coagulation assays.

METHODS

Whole blood from 18 patients undergoing cardiopulmonary bypass (CPB) were mixed in vitro with pooled normal plasma, FVIII-deficient or FVIII-inhibitor plasma to affect functional FVIII levels. ACTs and heparin concentration by protamine titration were measured in whole blood mixture with/without emicizumab (50-100 μg/ml). Thrombin generation and plasmin generation were measured in the patient's plasma mixed with normal plasma or FVIII-inhibitor plasma to assess the impact of emicizumab under low TF activation.

RESULTS

FVIII inhibitors prolonged ACTs by 2.2-fold compared to those in normal plasma mixture at baseline. During CPB, ACTs in normal plasma mixture, and FVIII-deficient mixture were in 400s, but ACTs reached 900s in FVIII-inhibitor mixture. Emicizumab shortened ACTs by up to 100s in normal plasma mixture, and FVIII-deficient mixtures. ACTs remained over 600s in FVIII-inhibitor mixture, despite adding emicizumab at 100 μg/ml. Heparin concentration measured by TF-based protamine titration was unaffected. Emicizumab enhanced thrombin peak in the presence of FVIII inhibitors, whereas plasmin generation was mainly affected by thrombin generation, and systemic use of ɛ-aminocaproic acid.

CONCLUSIONS

FVIII inhibitors extensively prolong ACTs in heparinized whole blood, and clinical levels of emicizumab partially reverse ACT values. Protamine titration should be considered for optimal heparin monitoring in emicizumab-treated patients with FVIII inhibitors.

Perioperative Management of Hemophilia A Patients Undergoing Cardiac Surgery: A Literature Review of Published Cases

OBJECTIVE

To investigate the perioperative management of patients with hemophilia A (HA) who undergo cardiac surgery.

DESIGN

Retrospective analysis of the published literature.

SETTING

University hospital.

PARTICIPANTS

HA patients undergoing cardiac surgery.

INTERVENTIONS

The PubMed, Embase, Web of Science Core Collection, CNKI, VIP, and WANFANG databases were searched with the terms "hemophilia A," "cardiac surgery," "cardiopulmonary bypass," "coronary artery bypass graft," "valve disease," and "congenital heart disease" to identify relevant articles. Data regarding patient characteristics, perioperative management protocols, and clinical outcomes were extracted and analyzed.

MEASUREMENTS AND MAIN RESULTS

Fifty articles, with 72 patients aging from 12 days to 80 years, were included. The analyzed population consisted of 36 (50%) mild HA, 10 (14%) moderate HA, and 25 (35%) severe HA patients. Factor VIII inhibitors were detected in 7 cases. Surgical procedures included 27 coronary artery bypass grafting procedures, 15 valve surgeries, 8 combined coronary artery bypass grafting with valve surgery procedures (1 with left ventricular assist device), 1 ventricular aneurysm resection with valve surgery, 11 corrections of congenital heart disease, 7 adult aortic surgeries, 3 heart transplantations, and 1 repair of heart injury. Factor VIII concentrates were used as a substitution therapy to ensure normalization of perioperative coagulation function. Although an uneventful clinical outcome was achieved in the majority of cases, 20% of patients developed complications with different severities.

CONCLUSIONS

Execution of a perioperative management strategy with a multidisciplinary approach, a thorough factor replacement protocol, and careful monitoring of factor levels facilitate an optimal outcome for HA patients undergoing cardiac surgery.

Consensus review of the treatment of cardiovascular disease in people with hemophilia A and B

With advances in care, increasing numbers of people with hemophilia (PWH) achieve near-normal life expectancies and present with typical age-related cardiovascular conditions. Evidence-based guidelines for medical or surgical management of cardiovascular conditions in individuals with hemophilia are limited. Published recommendations exist for the management of some common cardiovascular conditions (eg, ischemic heart disease, atrial fibrillation), but identifying optimal strategies for anticoagulant or antithrombotic therapy constitutes the primary challenge of managing nonoperative cardiovascular disease (CVD) in PWH. In general, as long as factor concentrates or other hemostatic therapies maintain adequate hemostasis, the recommended medical and surgical management of CVD in PWH parallels that in individuals without hemophilia. The presence of factor inhibitors complicates hemophilia management. Published outcomes of CVD treatment in PWH are similar to those in the general population. Specific knowledge about factor replacement, factor inhibitors, and disease-specific treatment distinguishes the cardiovascular care of PWH from similar care of individuals without this rare bleeding disorder. Furthermore, a multidisciplinary approach incorporating a hematologist with an onsite coagulation laboratory, ideally associated with a hemophilia treatment center, is integral to the management of CVD in PWH.

Successful aortic valve replacement surgery in a patient with severe haemophilia a with low titre inhibitor

In spite of the modern day innovations, managing severe Haemophilia patients with inhibitors continues to be a challenge. The management of patients with severe haemophilia with inhibitors who are undergoing major surgeries like open heart surgery is technically demanding, fraught with peri-operative complications and needs a multidisciplinary approach. We describe a young man with severe haemophilia with low titre inhibitors who underwent a successful open heart surgery and aortic valve replacement, supported only with bolus doses of Factor VIII and tranexamic acid without any complications.

Comprehensive care of the patient with haemophilia and inhibitors undergoing surgery: practical aspects

Congenital haemophilia is a rare and complex condition for which dedicated specialized and comprehensive care has produced measurable improvements in clinical outcomes and advances in patient management. Among these advances is the ability to safely perform surgery in patients with inhibitor antibodies to factors VIII and IX, in whom all but the most necessary of surgeries were once avoided due to the risk for uncontrollable bleeding due to ineffectiveness of replacement therapy. Nevertheless, surgery continues to pose a major challenge in this relatively rare group of patients because of significantly higher costs than in patients without inhibitors, as well as a high risk for bleeding and other complications. Because of the concentration of expertise and experience, it is recommended that any surgery in patients with haemophilia and inhibitors be planned in conjunction with a haemophilia treatment centre (HTC) and performed in a hospital that incorporates a HTC. Coordinated, standard pre-, intra- and postoperative assessments and planning are intended to optimize surgical outcome and utilization of resources, including costly factor concentrates and other haemostatic agents, while minimizing the risk for bleeding and other adverse consequences both during and after surgery. This article will review the special considerations for patients with inhibitors as they prepare for and move through surgery and recovery, with an emphasis on the roles and responsibilities of individual members of the multidisciplinary team in facilitating this process.

Ventricular assist device as a bridge to transplant, and extracorporeal membrane oxygenation for primary graft failure in a child with hemophilia A

OBJECTIVE

To report the management of hemophilia in a patient with dilated cardiomyopathy during application of the Berlin-Heart biventricular assist.

DESIGN

Case report.

INTERVENTIONS AND RESULTS

The Berlin-Heart biventricular assist was successfully used as a bridge to heart transplantation (178 days) in a child with hemophilia A; post-transplant extracorporeal membrane oxygenation was implanted until the patient recovered from primary graft failure. Anticoagulant therapy varied as a function of patient status: 1) postoperative bleeding was treated by partial replacement of deficient factors (VII and VIII) and hemoderivatives in order to maintain factor VIII at 50% of normal levels; 2) once the bleeding had stopped, the effect of the hemophilia itself maintained the degree of anticoagulation required by the ventricular assist device; and 3) transplant surgery was followed by complete replacement of factor VIII and intravenous heparinization (a simple way of preventing clot formation in the device and to ensure proper scarring of surgical wounds).

CONCLUSIONS

Selection of anticoagulant therapy as a function of patient status in terms of bleeding and surgical-wound scarring progress is vital for the proper functioning of support techniques (Berlin-Heart biventricular assist and extracorporeal membrane oxygenation) in hemophiliac patients. Collagen dressings placed on surgical wounds achieved good functional and aesthetic results, as well as mechanically isolating the scars from the exterior.

Successful cryoablation of atrioventricular nodal reentrant tachycardia in a child with hemophilia A

We report the hematologic and invasive electrophysiologic management of a 12-year-old boy with mild hemophilia A (factor VIII deficiency) and atrioventricular nodal reentrant tachycardia. Thoughtful preparation with detailed input from the patient's comprehensive hemophilia center combined with vigilant pericatheterization hematologic management allowed for safe and successful cryoablation of this arrhythmia. Strategies for the management of patients with bleeding disorders who require invasive cardiac catheterization or surgery are reviewed.

Defining the role of recombinant activated factor VII in pediatric cardiac surgery: where should we go from here?

OBJECTIVES

Postoperative hemorrhage is a recognized complication of pediatric cardiac surgery. Both the immature coagulation system and increased susceptibility to hemodilution increase the likelihood of pediatric patients developing coagulopathy when compared with adult counterparts. Treatment options remain limited. Recombinant factor VII (rFVIIa) is a hemostatic agent increasingly used to reduce hemorrhage in other surgical settings, the role of which is unclear in this population. This article systematically reviews the published literature on the use of rFVIIa in pediatric cardiac surgery.

DATA SOURCES AND STUDY SELECTION

A systematic literature search identified reports of rFVIIa administration in pediatric patients undergoing cardiac surgery. Where possible, individual patient-specific data were extracted and pooled statistical analysis was performed.

DATA EXTRACTION AND SYNTHESIS

Twenty-nine articles reporting on the administration of rFVIIa to 169 patients were identified. rFVIIa has been administered to patients with predefined congenital abnormalities of hemostasis to arrest hemorrhage refractory to other interventions and prophylactically in the hope of reducing blood loss. Treatment regimens vary widely, in terms of both first and cumulative dose. Data on chest tube blood loss and two markers of coagulation were pooled and analyzed, and significant improvements were demonstrated. Mortality was 4.4% for the entire cohort but 20% of patients on extracorporeal membrane oxygenation suffered significant thromboembolic complications.

CONCLUSIONS

rFVIIa has an increasingly accepted role in the management of patients with congenital coagulopathies undergoing major surgery. However, randomized trials are required to define the role of rFVIIa as an adjunct to control major hemorrhage in the pediatric cardiac surgical population. Any future work must focus not only on benefits but also on patient safety, particularly, risk of morbid thromboembolic complication.

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.

Successful use of recombinant factor VIIa (NovoSeven) during cardiac surgery in a pediatric patient with Glanzmann thrombasthenia

Glanzmann thrombasthenia is a rare, hereditary, congenital disorder of platelet function characterized by inappropriate bleeding that is difficult to control. Recombinant activated factor VII (rFVIIa) is a new treatment that is used to stop bleeding and provide surgical support for these patients. This report describes the use of rFVIIa to prevent serious bleeding during and after open-heart surgery in a child with Glanzmann thrombasthenia.

Catastrophic microangiopathy induced by high-titre factor VIII inhibitors after liver transplantation for haemophilia A with cirrhosis

Liver transplantation may induce immune tolerance to factor VIII inhibitors but de novo development of inhibitors after transplantation may cause intractable haemorrhage. We report a patient with mild haemophilia A and high-titre FVIII inhibitors who received an orthotopic liver transplantation for complications of hepatitis C virus cirrhosis. Recombinant activated FVII was used in addition to routine haemostatic agents. Conventional immunosuppression was supplemented with antithymocyte globulin and cyclophosphamide. FVIII inhibitors disappeared from the circulation with liver transplantation but they were found to have bound to the graft endothelium, which became activated and induced catastrophic microangiopathy. A subsequent anamnestic response resulted in FVIII inhibitor titres of 1000 Bethesda Units. Uncontrollable haemorrhage persisted until the recipient's death. In patients with high-titre FVIII inhibitors resilient desensitization is required before liver transplantation.

Cardiac surgery in patients on antiplatelet and antithrombotic agents

The widespread application of antithrombotic agents carries significant potential for inducing excessive peri-operative hemorrhage during cardiac surgery. Specific surgical and medical strategies can be employed to attenuate this bleeding. These antithrombotic agents and anti-hemorrhagic measures will be reviewed in depth.

Intraoperative Recombinant Activated Factor VII for Emergent Epidural Hematoma Evacuation

We report a case of a chronically anticoagulated 59-yr-old woman who underwent an L4 to L5 epidural block to relieve her low back pain and subsequently developed a T7 to L5 epidural hematoma with cauda equina and conus compression. Fresh frozen plasma and vitamin K were given before surgery, whereas recombinant activated factor VII was administered during surgery to reverse the coagulopathy and to enable the emergent laminectomy and hematoma evacuation. Recombinant activated factor VII administration proved to be a useful adjunct in the emergent surgical management of a thoracolumbar epidural hematoma.

Reversal of Direct Thrombin Inhibition After Cardiopulmonary Bypass in a Patient with Heparin-Induced Thrombocytopenia

We treated persistent hemorrhage after cardiopulmonary bypass in a heart transplant recipient who had received anticoagulation with the direct thrombin inhibitor bivalirudin by a combination therapy aimed at reducing the plasma concentration of the thrombin antagonist (hemodialysis and modified ultrafiltration), increasing the concentration of thrombin at bleeding sites (recombinant factor VIIa), and increasing the plasma concentration of other coagulation factors (fresh frozen plasma and cryoprecipitate). The bleeding was controlled, and there was no thrombotic complication.

IMPLICATIONS

A combination of modified ultrafiltration, hemodialysis, and the administration of recombinant factor VIIa, fresh frozen plasma, and cryoprecipitate may reverse the anticoagulant effect of bivalirudin.

Novel hemostatic alternatives in reconstructive surgery

Congenital vascular lesions are classed as hemangiomas, vascular malformations, or vascular tumors according to their histology and etiology. The majority of hemangiomas are benign and often involute before the child reaches the age of 12. Severe hemangiomas and vascular malformations were historically viewed as effectively inoperable due to the high risk of potentially catastrophic bleeding during surgery. An effective system of classification and increasing range of therapeutic options have improved the prognosis for many patients, but surgical resection of these lesions remains a serious undertaking. Topical hemostatic agents are widely used and effective in many cases for the control of intraoperative bleeding. The main limitations of these agents are their variability and lack of efficacy in severe bleeding, or in coagulopathic or anticoagulant-treated patients. This paper reviews recent developments in this field, including the possible placental origin of hemangiomas, and discusses current approaches to hemostasis during reconstructive surgery. We also discuss the recent introduction of recombinant activated factor VII (rFVIIa) as a systemic hemostatic agent, including our own experience using this treatment.

Use of recombinant factor VIIa as a rescue treatment for intractable bleeding following repeat aortic arch repair

Hemorrhage, refractory to aggressive conventional therapy, at a rate of 16 L/hr following separation from cardiopulmonary bypass for aortic arch repair, was controlled with a dose of 90 microg/kg of recombinant factor VIIa, repeated once after 2 hours.

Extracorporeal membrane oxygenation as a bridge to cardiac transplantation in a patient with cardiomyopathy and hemophilia A

OBJECTIVE

To report the use of extracorporeal membrane oxygenation (ECMO) as a bridge to cardiac transplantation in a patient with hemophilia A and dilated cardiomyopathy.

DESIGN

Case report.

INTERVENTIONS AND RESULTS

During ECMO factor VIII concentrate was administered to maintain a factor VIII level close to 50% of normal control both to decrease the risk of bleeding and to allow standard anticoagulation with heparin. The patient developed an inhibitor to exogenous factor VIII during hospitalization, which was successfully managed with a high-dose continuous infusion of factor VIII during ECMO, the transplant operation, and the postoperative period.

CONCLUSIONS

We report the successful use of ECMO as a bridge to cardiac transplantation in a patient with hemophilia A and low-level factor VIII inhibitors.

First-time development of FVIII inhibitor in haemophilia patients during the postoperative period

Development of inhibitor to FVIII in haemophilia patients is well-known and is not uncommon. However, their development for the first time during the postoperative period has hardly been reported. In a developing country such as India, where resources are limited, development of such an eventuality may prove disastrous. However, as many of our patients are sparingly treated, therefore, even if they test negative for the inhibitor preoperatively, they may get the requisite FVIII antigenic stimulation during the preoperative and immediate postoperative period, leading to the development of inhibitors during this critical time of wound healing. We describe here six patients who developed such an inhibitor, from a group of 35 patients with haemophilia A who underwent various surgical procedures (19%). We stress that such an eventuality may not remain rare in developing countries as more patients of severe haemophilia undergo surgery and are therefore challenged for the first time in their life with large amounts of FVIII concentrate during their preoperative period.

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.