Safety and Efficacy of Recombinant Activated Factor VII: A Randomized Placebo-Controlled Trial in the Setting of Bleeding After Cardiac Surgery

Outcomes associated with absent blood product utilization in Jehovah's witness patients compared to the standard of care in cardiac surgery: A ten-year experience

INTRODUCTION

For Jehovah's Witness (JW) patients requiring cardiac surgery, various strategies such as preoperative use of erythropoietin stimulating agents (ESAs), intravenous iron (IVI), and non-pharmacologic interventions have emerged to prevent complications from blood loss given transfusion is not acceptable in this population.

METHODS

Retrospective case-control of cardiac surgeries performed by the same surgeon between 1/1/2011 and 8/30/2021. JW patients were matched to non-JW who received blood products and non-JW who did not receive blood products on a 1:2:2 basis. Patients were matched on procedure, age, gender, and Society of Thoracic Surgeons morbidity score. Eligible patients were aged >18 years and had a sternotomy procedure. The primary efficacy and safety outcomes included mean hematocrit values perioperatively and thrombotic events.

RESULTS

A total of 27 JW, 52 non-JW transfused, and 53 non-JW not transfused patients were included in the analysis. JW patients had significantly higher mean hematocrits at every time point when compared to non-JW transfused patients and at all time points except clinic and the last recorded operating room value when compared to non-JW not transfused patients. No significant differences in thrombotic rates were found between groups, however there was a numerically higher incidence in the JW population (JW: 7.4%; non-JW transfused: 0%; non-JW not transfused: 1.9%; p = .106).

CONCLUSION

A blood conservation protocol in a JW population was associated with higher perioperative hematocrit values when compared to matched controls. Further prospective study is warranted before applying similar protocols to other populations given the possibility for an increased rate of venous thromboembolism.

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.

Comparison of Low Dose Recombinant Factor VIIa and 4-Factor Prothrombin Complex Concentrate for Treatment of Bleeding Related to Cardiac Surgery

Background: Recombinant factor VIIa (rFVIIa) and prothrombin concentrate complex (PCC) are used for uncontrolled bleeding in cardiac surgery (CS), however, there are limited direct comparisons of these agents. Objective: To evaluate the efficacy and safety of rFVIIa and PCC in CS related bleeding. Methods: This retrospective study included adult CS patients who received either low dose rFVIIa (<30 mcg/kg) or 4-factor PCC. The primary outcome was transfusion requirements of packed red blood cells (pRBC) within 6 hours of factor administration. Secondary efficacy outcomes included transfusion requirements 0-18 hours, doses of additional factor product, thrombotic events, and acute kidney injury (AKI). Results: A total of 179 patients were included (n = 78 rFVIIa; n = 101 PCC). Of patients who received blood products, there was no difference in the requirement of pRBCs within 6 hours (73.8 vs 68.9%, P = .5359) or in the median amount of pRBC transfused (500 mL vs 640 mL, P = .0723) in the rFVIIa and PCC groups respectively. Patients in the PCC group were more likely to require additional factor products (24.4% vs 47.5%, P = .0015), develop AKI (12.8% vs 25.7%, P = .0325), have longer ICU lengths of stay [2 (IQR 1-5) vs 4 (IQR 2-6), P = .0487] and greater in-hospital mortality (2.6% vs 10.9%, P = .033). There was no difference in thrombotic events. Conclusion: Although, there was no difference in pRBC transfusion requirements between PCC and rFVIIa, more patients in the PCC group required additional factor products and had increased adverse effects. Further comparisons of PCC and rFVIIa are warranted.

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.

The Year in Coagulation and Transfusion: Selected Highlights from 2022

This is an annual review to cover highlights in transfusion and coagulation in patients undergoing cardiovascular surgery. The goal of this article is to provide readers with a focused summary of the most important transfusion and coagulation topics published in 2022. This includes a discussion covering the management of anemia and red blood cell transfusion, the management of factor Xa inhibitors, updates in coagulation testing, updates in the use of factor concentrates, advances in platelet therapy, advances in anticoagulation management of patients on extracorporeal membrane oxygenation and other forms of mechanical circulatory support, and advances in the diagnosis and management of heparin-induced thrombocytopenia.

Development of the Modern Cardiothoracic Intensive Care Unit and Current Management

The modern cardiothoracic intensive care unit (CTICU) developed as a result of advances in critical care, cardiology, and cardiac surgery. Patients undergoing cardiac surgery today are sicker, frailer, and have more complex cardiac and noncardiac morbidities. CTICU providers need to understand postoperative implications of different surgical procedures, complications that can occur in CTICU patients, resuscitation protocols for cardiac arrest, and diagnostic and therapeutic interventions such as transesophageal echocardiography and mechanical circulatory support. Optimum CTICU care requires a multidisciplinary team with collaboration between cardiac surgeons and critical care physicians with training and experience in the care of CTICU patients.

Off-label Use of Recombinant Activated Factor VII for Cardiac Surgical Bleeding

Recombinant activated factor VII has been widely used in an off-label manner for cardiac surgical bleeding. Recent reports have administered recombinant activated factor VII earlier in the course of bleeding and at lower doses than initially reported. This review will discuss the history, mechanism, current recommendations for use, and recent data on the use of recombinant activated factor VII in cardiac surgical bleeding.

Effect of Desmopressin on Bleeding After Heart Surgeries: A Narrative Review

Desmopressin is an analog of the antidiuretic hormone (vasopressin), which causes anticoagulant activity by increasing plasma factor 8. The use of desmopressin dates back to 1977, when this hormone was used to prevent bleeding during tooth extraction and surgery in patients with hemophilia A and von Willebrand disease. After that, this hormone was expanded to prevent bleeding in congenital defects and conditions such as chronic kidney and liver failure. Also, this hormone is used to prevent bleeding in major surgeries such as heart surgery, where the patient loses much blood and needs a blood transfusion. Considering the importance of desmopressin in bleeding control, the present study was conducted to investigate the possible effect of this hormone in heart surgery.

Comparison of Prothrombin Complex Concentrate with Activated Factor VII Use for Bleeding Following Cardiopulmonary Bypass in Children

OBJECTIVE

This study aims to compare the efficacy and safety of activated recombinant factor VII (rFVIIa) and prothrombin complex concentrate (PCC) in the treatment of bleeding complications following surgery requiring cardiopulmonary bypass (CPB) in children.

DESIGN/METHODS

This is a retrospective chart review of a single institution comprising patients aged 0 to 18 years old with congenital heart disease. Patients must have received either PCC or rFVIIa after coming off CPB. Our primary efficacy endpoint is time in the operating room from off-CPB to pediatric intensive care unit admission. Our primary safety endpoint is thrombosis through 30 days.

RESULTS

Our primary efficacy outcome was significantly shorter in the PCC group compared with the rFVIIa group (P < .0001). Similarly, secondary efficacy outcomes of packed red blood cell administration, chest tube output, and transfusion exposures all significantly favored PCC administration. However, CPB time was significantly longer, and body temperatures were significantly lower, in the rFVIIa group. Safety outcomes, including our primary safety outcome of thrombosis through 30 days, were similar between the two groups.

CONCLUSION

This study questions whether PCC could be favored over rFVIIa for hemostasis in children with congenital heart disease following CPB surgery. In addition, this study has found no difference when comparing PCC and rFVIIa in terms of safety outcomes, particularly thrombosis events. There are several limitations to this study due to the retrospective nature of the design and the differences between the two study groups. Despite the limitations, this study suggests that relatively early administration of PCC could be favored over delayed administration of rFVIIa to control recalcitrant post-CPB bleeding in the operating room.

Recombinant Activated Factor VII in Aortic Surgery for Patients Under Hypothermic Circulatory Arrest

Purpose

We aimed to identify the risk factors of critical bleeding and investigate the safety of recombinant activated factor VII (rFVIIa) in aortic surgery under hypothermic circulatory arrest (HCA).

Patients and Methods

The present single-center retrospective study compared the baseline characteristics of 144 patients who underwent aortic surgery under HCA at our institute. Among the total cohort of 144 patients, 42 received rFVIIa (rFVIIa group), while the remaining 102 patients did not (non-rFVIIa group). Perioperative bleeding and transfusions, postoperative 30-day mortality, and adverse events (AEs) were analyzed in 29 propensity score-matched pairs.

Results

Before surgery, the rFVIIa group demonstrated a greater number of shocks (p=0.019), higher JapanSCORE II mortality rate (p=0.033), low platelet count (p=0.015) and fibrinogen (p<0.001) level, prolonged activated partial thromboplastin time (aPTT) (p=0.005) and prothrombin time international normalized ratio (PT-INR) (p=0.006), and longer aortic cross clamp time (p=0.049). Postoperative bleeding, transfusion, 30-day mortality, and AEs were comparable between the groups both in the entire-unmatched cohort and propensity score matching cohort.

Conclusion

Preoperative shock, higher JapanSCORE II mortality rates, low platelet and fibrinogen levels, prolonged aPTT and PT-INR, and longer aortic clamping time might be risk factors for excessive bleeding and indicate the need for rFVIIa treatment. The present study suggests that rFVIIa can be safely used to address critical and continuous bleeding in spite of adequate transfusion and supplementation of other coagulation factors in aortic surgery under HCA, without an increase in 30-day mortality and AEs.

Consensus Statement: Hemostasis Trial Outcomes in Cardiac Surgery and Mechanical Support

BACKGROUND

Research evaluating hemostatic agents for the treatment of clinically significant bleeding has been hampered by inconsistency and lack of standardized primary clinical trial outcomes. Clinical trials of hemostatic agents in both cardiac surgery and mechanical circulatory support, such as extracorporeal membrane oxygenation and ventricular assist devices, are examples of studies that lack implementation of universally accepted outcomes.

METHODS

A subgroup of experts convened by the National Heart, Lung, and Blood Institute and the US Department of Defense developed consensus recommendations for primary outcomes in cardiac surgery and mechanical circulatory support.

RESULTS

For cardiac surgery the primary efficacy endpoint of total allogeneic blood products (units vs mL/kg for pediatric patients) administered intraoperatively and postoperatively through day 5 or hospital discharge is recommended. For mechanical circulatory support outside the perioperative period the recommended primary outcome for extracorporeal membrane oxygenation is a 5-point ordinal score of thrombosis and bleeding severity adapted from the Common Terminology Criteria for Adverse Events version 5.0. The recommended primary endpoint for ventricular assist device is freedom from disabling stroke (Common Terminology Criteria for Adverse Events AE ≥ grade 3) through day 180.

CONCLUSIONS

The proposed composite risk scores could impact the design of upcoming clinical trials and enable comparability of future investigations. Harmonizing and disseminating global consensus definitions and management guidelines can also reduce patient heterogeneity that would confound standardized primary outcomes in future research.

Acquired von Willebrand syndrome is common in infants with systemic-to-pulmonary shunts: Retrospective case-series

BACKGROUND

Although acquired von Willebrand syndrome (aVWS) has been described in congenital heart disease before, anatomical features leading to aVWS with characteristic reduction or loss of high molecular weight von Willebrand multimers (HMWM) are not well known. This study assesses the prevalence and effects of aVWS in infants with systemic-to-pulmonary shunts (SPS).

METHODS

This retrospective single-center study analyzes diagnostic data of infants with complex congenital heart defects requiring palliation with SPS. During the study period between 12/15-01/17 fifteen consecutive patients were eligible for analysis. Results of von Willebrand factor antigen (VWF:Ag), collagen binding activity (VWF:CB) and von Willebrand factor multimer analysis were included.

RESULTS

In all 15 patients with SPS an aVWS could be found. Blood samples were collected between 5 and 257 days after shunt implantation (median 64 days). None of the patients demonstrated increased bleeding in everyday life. However, 6 out of 15 patients (40%) showed postoperative bleeding complications after SPS implantation. Following shunt excision multimeric pattern normalized in 8 of 10 (80%) patients studied.

CONCLUSIONS

This study shows that in patients undergoing SPS implantation aVWS might emerge. Pathogenesis can be explained by shear stress resulting from turbulent flow within the shunt. Knowledge of aVWS existence is important for the consideration of replacement therapy with von Willebrand factor containing products and antifibrinolytic treatment in bleeding situations. Implementation of methods for rapid aVWS detection is required to achieve differentiated hemostatic therapy and reduce the risk of complications caused by empiric replacement therapy.

Recombinant activated factor VII for hemostasis in patients undergoing complex ascending aortic surgery: A single-center, single-surgeon retrospective analysis

BACKGROUND

Use of recombinant activated factor VII (rFVIIa) to achieve hemostasis during cardiac surgery continues to be debated, as support for its efficacy and safety has not been consistent. We examined our experience with rFVIIa for achieving hemostasis in high-risk patients undergoing complex ascending aortic surgery.

METHODS

We reviewed patients who underwent complex ascending aortic surgery performed by a single surgeon (C. K. R.) from August 2014 to February 2019. Outcomes of patients who received rFVIIa were compared with those who did not.

RESULTS

Of 59 consecutive patients, 20 patients (33.9%) received rFVIIa, whereas 39 (66.1%) did not. Median dose was 45.4 mcg/kg. rFVIIa was administered intraoperatively to 95% of patients who received it. Most patients underwent combined aortic valve, ascending aorta, and aortic arch surgery (80.0% vs. 64.1%, p = .52). Patients receiving rFVIIa had longer mean cross clamp times (212 vs. 173 min, p = .03) and received a greater median number of intraoperative blood products (18.5 vs. 12.0, p < .001). The number of patients who needed postoperative products (75.0% vs. 60.5%, p = .39), the median number of blood products transfused postoperatively (2 vs. 2, p = .40), and chest tube output (1138 vs. 805 ml, p = .17) were similar between groups. In-hospital mortality was similar between groups (10.0% vs. 10.3%, p = 1.00). Incidences of postoperative stroke (10.0% vs. 13.5%, p = 1.00) and thromboembolic events (10.0% vs. 13.5%, p = 1.00) were similar.

CONCLUSIONS

Administration of rFVIIa intraoperatively for refractory bleeding during complex ascending aortic surgery provided hemostasis without greater in-hospital mortality or a higher risk of stroke and thromboembolic events.

Very low-dose recombinant Factor VIIa administration for cardiac surgical bleeding reduces red blood cell transfusions and renal risk: a matched cohort study

Outcomes following administration of very-low-dose recombinant activated factor VIIa (vld-rFVIIa) for cardiac surgical bleeding remain debatable. We sought to determine the association of vld-rFVIIa and adverse surgical outcomes. Retrospective, cohort matching of patients undergoing cardiac surgery who received vld-rFVIIa (median 13.02 μg/kg) for perioperative bleeding were matched to cardiac surgical patients who had bleeding and received standard of care for bleeding without Factor VIIa administration. Of the 362 matched patients (182 in each group), patients who received rFVIIa required significantly less red blood cell transfusions [median 3 units (range 0--60, IQR = 4 units) versus 4 units (range 2-34, IQR = 4 units); P = 0.0004], decreased length of hospital stay (median 8 versus 9 days; P = 0.0158) and decreased renal risk (P < 0.0001). Incidence of renal failure, postoperative infection, postoperative thrombosis, prolonged ventilation, total ICU hours and 30-day mortality were not different between the two groups. Vld-rFVIIa for cardiac surgical bleeding was associated with decreased red blood cell transfusion, renal risk and length of hospital stay without increased thromboembolism or mortality when compared to patients who had cardiac surgical bleeding and received standard of care without Factor VIIa.

Recommended primary outcomes for clinical trials evaluating hemostatic blood products and agents in patients with bleeding: Proceedings of a National Heart Lung and Blood Institute and US Department of Defense Consensus Conference

ABSTRACT

High-quality evidence guiding optimal transfusion and other supportive therapies to reduce bleeding is needed to improve outcomes for patients with either severe bleeding or hemostatic disorders that are associated with poor outcomes. Alongside challenges in performing high-quality clinical trials in patient populations who are at risk of bleeding or who are actively bleeding, the interpretation of research evaluating hemostatic agents has been limited by inconsistency in the choice of primary trial outcomes. This lack of standardization of primary endpoints or outcomes decreases the ability of clinicians to assess the validity of endpoints and compare research results across studies, impairs meta-analytic efforts, and, ultimately, delays the translation of research results into clinical practice. To address this challenge, an international panel of experts was convened by the National Heart Lung and Blood Institute and the US Department of Defense on September 23 and 24, 2019, to develop expert opinion, consensus-based recommendations for primary clinical trial outcomes for pivotal trials in pediatric and adult patients with six categories in various clinical settings. This publication documents the conference proceedings from the workshop funded by the National Heart Lung and Blood Institute and the US Department of Defense that consolidated expert opinion regarding clinically meaningful outcomes across a wide range of disciplines to provide guidance for outcomes of future trials of hemostatic products and agents for patients with active bleeding.

In vitro characterization of CT-001-a short-acting factor VIIa with enhanced prohemostatic activity

BACKGROUND

Traumatic injury and the associated acute bleeding are leading causes of death in people aged 1 to 44 years. Acute bleeding in pathological and surgical settings also represents a significant burden to the society. Yet there are no approved hemostatic drugs currently available. While clinically proven as an effective pro-coagulant, activated factor VII (FVIIa) use in acute bleeding has been hampered by unwanted thromboembolic events. Enhancing the ability of FVIIa to quickly stop a bleed and clear rapidly from circulation may yield an ideal molecule suitable for use in patients with acute bleeding.

OBJECTIVES

To address this need and the current liability of FVIIa, we produced a novel FVIIa molecule (CT-001) with enhanced potency and shortened plasma residence time by cell line engineering and FVIIa protein engineering for superior efficacy for acute bleeding and safety.

METHODS

To address safety, CT-001, a FVIIa protein with 4 desialylated N-glycans was generated to promote active recognition and clearance via the asialoglycoprotein receptor. To enhance potency, the gamma-carboxylated domain was modified with P10Q and K32E, which enhanced membrane binding.

RESULTS

Together, these changes significantly enhanced potency and clearance while retaining the ability to interact with the key hemostatic checkpoint proteins antithrombin and tissue factor pathway inhibitor.

CONCLUSIONS

These results demonstrate that a FVIIa molecule engineered to combine supra-physiological activity and shorter duration of action has the potential to overcome the current limitations of recombinant FVIIa to be a safe and effective approach to the treatment of acute bleeding.

Impact of Early, Low-Dose Factor VIIa on Subsequent Transfusions and Length of Stay in Cardiac Surgery

OBJECTIVE

Recombinant factor VII (rFVIIa) is used to treat cardiac surgical bleeding in an off-label manner. However, optimal dosing and timing of administration to provide efficacious yet safe outcomes remain unknown.

DESIGN

Retrospective, observational study.

SETTING

Tertiary care academic center.

PARTICIPANTS

Cardiac surgical patients (N = 214) who received low-dose rFVIIa for cardiac surgical bleeding.

INTERVENTIONS

Patients were allocated into one of three groups based on timing of rFVIIa administration during the course of bleeding resuscitation based on the number of hemostatic products given before rFVIIa administration: group one = ≤one products (n = 82); group two = two-to-four products (n = 73); and group three= ≥five products (n = 59).

MEASUREMENTS AND MAIN RESULTS

Patients who received low-dose rFVIIa later in the course of bleeding resuscitation (group three) had longer intensive care unit stays (p = 0.014) and increased incidence of postoperative renal failure when compared with group one (p = 0.039). Total transfusions were lowest in patients who received rFVIIa early in the course of resuscitation (group one) (median, two [interquartile range (IQR), 1-4.75]) and highest in group three (median, 11 [IQR, 8-14]; p < 0.001). Subsequent blood product transfusions after rFVIIa administration were highest in group two (p = 0.003); however, the median for all three groups was two products. There were no differences in thrombosis, reexplorations, or mortality in any of the groups.

CONCLUSIONS

This study identified no differences in adverse outcomes based on timing of administration of low-dose rFVIIa for cardiac surgical bleeding defined by stage of resuscitation, but the benefits of early administration remain unclear.

Efficacy, Safety, and Strategies for Recombinant-Activated Factor VII in Cardiac Surgical Bleeding: A Narrative Review

As perioperative bleeding continues to be a major source of morbidity and mortality in cardiac surgery, the search continues for an ideal hemostatic agent for use in this patient population. Transfusion of blood products has been associated both with increased costs and risks, such as infection, prolonged mechanical ventilation, increased length of stay, and decreased survival. Recombinant-activated factor VII (rFVIIa) first was approved for the US market in 1999 and since that time has been used in a variety of clinical settings. This review summarizes the existing literature pertaining to perioperative rFVIIa, in addition to society recommendations and current guidelines regarding its use in cardiac surgery.

Managing the coagulopathy associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) has allowed for significant surgical advancements, but accompanying risks can be significant and must be expertly managed. One of the foremost risks is coagulopathic bleeding. Increasing levels of bleeding in cardiac surgical patients at the time of separation from CPB are associated with poor outcomes and mortality. CPB-associated coagulopathy is typically multifactorial and rarely due to inadequate reversal of systemic heparin alone. The components of the bypass circuit induce systemic inflammation and multiple disturbances of the coagulation and fibrinolytic systems. Anticipating coagulopathy is the first step in managing it, and specific patient and procedural risk factors have been identified as predictors of excessive bleeding. Medication management pre-procedure is critical, as patients undergoing cardiac surgery are commonly on anticoagulants or antiplatelet agents. Important adjuncts to avoid transfusion include antifibrinolytics, and perfusion practices such as red cell salvage, sequestration, and retrograde autologous priming of the bypass circuit have varying degrees of evidence supporting their use. Understanding the patient's coagulation status helps target product replacement and avoid larger volume transfusion. There is increasing recognition of the role of point-of-care viscoelastic and functional platelet testing. Common pitfalls in the management of post-CPB coagulopathy include overdosing protamine for heparin reversal, imperfect laboratory measures of thrombin generation that result in normal or near-normal laboratory results in the presence of continued bleeding, and delayed recognition of surgical bleeding. While challenging, the effective management of CPB-associated coagulopathy can significantly improve patient outcomes.

A Comparison of Prothrombin Complex Concentrate and Recombinant Activated Factor VII for the Management of Bleeding With Cardiac Surgery

Bleeding following cardiac surgery that warrants transfusion of blood products is associated with significant complications, including increased mortality at 1 year following surgery. Factor concentrates, such as prothrombin complex concentrate (PCC), or recombinant activated factor VII (rFVIIa) have been used off-label for bleeding in cardiac surgery that is refractory to conventional therapy. The objective of this retrospective study is to assess the hemostatic effectiveness of 4-factor PCC or rFVIIa for bleeding after a broad range of cardiac surgeries. Patients were included if they were at least 18 years of age and had undergone cardiac surgery with bleeding requiring intervention with 4-factor PCC or rFVIIa. There were no differences observed in the number of packed red blood cells (4-factor PCC: 2 units vs. rFVIIa: 2 units), fresh frozen plasma (0 units vs. 1 unit) or platelet (2 units vs. 2 units) transfusions following the administration of 4-factor PCC or rFVIIa. The patients in the rFVIIa group, required more cryoprecipitate than those in the 4-factor PCC group (4-factor PCC: 2 units (range 0-6) vs. rFVIIa: 2 units (range 0-8), p = 0.03). There were no differences in secondary outcomes of chest tube output at 2, 6, 12 and 24 hours, nor was there a difference in reexploration rates or the median length of stay in the intensive care unit. Thromboembolic complications at 30 days were similar between the two groups (4-factor PCC: 13% vs. rFVIIa 26%, p = 0.08). The total median dose requirement for 4-factor PCC was 1000 units (15 units/kg) and 2 mg (20 mcg/kg) for rFVIIa. The results demonstrate feasibility of utilizing the minimum amount of drug in order to achieve a desired effect. Both 4-factor PCC and rFVIIa appear to be safe and effective options for the management of bleeding associated with cardiac surgery.

Use of Low-Dose Recombinant Factor Ⅶa for Uncontrolled Perioperative Bleeding

Background

Recombinant activated factor VIIa (rFVIIa) is a prohemostatic agent initially approved for use in hemophilia patients and has also been used for a diverse range of off-label indications in the context of massive uncontrolled blood loss; however, no convincing evidence exists regarding the optimal dose of rFVIIa to treat uncontrolled bleeding in surgical patients.

Aim

To evaluate the effects and safety of a very low dose of rFⅦa in patients with uncontrolled perioperative bleeding in the surgical intensive care unit (ICU).

Methods

55 patients from Beijing Hospital, who received rFⅦa between July 2004 and November 2018 for uncontrolled perioperative bleeding were included. The controls were matched for age, sex, severity, and operation type. The baseline demographics, survival, changes in bleeding and transfusion, coagulation parameters and complications were analyzed.

Results

A low dose of rFⅦa (2.0∼3.6 mg, with a median dose of 39.02 μg/kg) appears to be effective in controlling massive hemorrhage (with an effective rate of 74.55%), and can reduce volume of red blood cell transfusion, improve coagulation status, while has a relatively low risk of thromboembolic complications (3.6%).

Conclusion

In patients with uncontrolled perioperative bleeding, a low dose of rFⅦa could be used when traditional methods are ineffective.

Adequacy of hemostatic resuscitation improves therapeutic efficacy of recombinant activated factor VII and reduces reexploration rate for bleeding in postoperative cardiac surgery patients with refractory hemorrhage

Background:

Excessive bleeding and surgical reexploration are common complications that increase the risk of multi-organ failure and prolonged hospitalization after cardiac surgery. Off-label use of recombinant activated factor VII (rFVIIa) is a recommended treatment for refractory bleeding.

Objective:

The objective of the study is to determine if the adequacy of hemostatic resuscitation enhances the efficacy of rFVIIa.

Methods:

This retrospective, observational, cohort study included patients who received rFVIIa for refractory postoperative bleeding after cardiac surgery. Patients were divided into two groups based on the presence or absence of adequate coagulation resuscitation before rFVIIa administration, defined as international ratio (INR) ≤1.5, platelet count ≥100 K/mL, and fibrinogen ≥200 mg/dL. The failure of rFVIIa treatment was defined as surgical reexploration within 24 h, thoracostomy drainage >400 mL/h within 6 h or transfusion of additional blood products or another rFVIIa dose within 6 h after initial rFVIIa dose.

Results:

Of the 3833 patients, screened who underwent cardiothoracic surgery procedures, 58 patients received rFVIIa for refractory postoperative bleeding. Successful hemostasis with rFVIIa was more likely in patients who were adequately resuscitated compared with those who were not (20 [71.4%] vs. 10 [33.3%], respectively; P = 0.0046). Multiple logistic regression analysis indicated that patients who were adequately resuscitated before rFVIIa were less likely to fail treatment (odds ratio, 0.16; 95% confidence interval [0.04–0.62]; P = 0.007).

Conclusions:

The therapeutic efficacy of rFVIIa is dependent on the adequacy of hemostatic resuscitation; restoration of normal serum fibrinogen, INR, and platelet counts >100 K/mL may provide an adequate substrate for rFVIIa to be effective in managing refractory postoperative cardiac surgical bleeding.

Use of Factor VIIa and Anti-inhibitor Coagulant Complex in Pediatric Cardiac Surgery Patients

OBJECTIVES

Postoperative bleeding is a common cause of morbidity and mortality in cardiac patients who undergo cardiopulmonary bypass (CPB). Pediatric patients are especially at risk for adverse effects of surgery and CPB on the coagulation system. This can result in bleeding, transfusions, and poor outcomes. Excessive bleeding unresponsive to blood products can warrant the off-label use of recombinant activated clotting factor VIIa (rFVIIa) and/or anti-inhibitor coagulant complex (FEIBA). Several studies have shown the utility in these agents off-label in patients who have undergone cardiac bypass surgery with acute bleeding episodes that are refractory to blood products. However, data regarding use of these agents in pediatrics are sparse. The purpose of this study is to report the use of rFVIIa and FEIBA in pediatric cardiac surgery patients in our institution.

METHODS

This was a retrospective chart review of pediatric cardiothoracic surgery patients who received rFVIIa or FEIBA at Children's Healthcare of Atlanta during the study period.

RESULTS

Thirty-three patients received rFVIIa and 9 patients received FEIBA either intraoperatively or postoperatively for bleeding related to the cardiac procedure. Approximately 13% of rFVIIa patients and 55% of FEIBA patients required repeat doses. There were decreases for all blood products administered after rFVIIa and FEIBA were given. However, the doses used did not correlate with either positive or negative outcomes. Seventeen percent (n = 7) of rFVIIa patients experienced a thrombus and 22% (n = 2) of FEIBA patients experienced a thrombus.

CONCLUSIONS

Both rFVIIa and FEIBA reduced blood product usage in pediatric patients following cardiac procedures.

Antithrombotic and hemostatic stewardship: evaluation of clinical outcomes and adverse events of recombinant factor VIIa (Novoseven®) utilization at a large academic medical center

Background:

Recombinant factor VIIa (rFVIIa) (Novoseven®) is utilized for the reversal of anticoagulation-associated bleeding and refractory bleeding in cardiac surgery. In August 2015, rFVIIa was transferred from the blood bank to the pharmacy at New York University (NYU) Langone Health. Concordantly, an off-label dosing guideline was developed. The objective of this study was to describe utilization and cost of rFVIIa and assess compliance to our dosing guideline.

Methods:

We performed a retrospective, observational review of rFVIIa administrations post-implementation of an off-label dosing guideline. All patients who received rFVIIa between September 2015 and June 2017 were evaluated. For each rFVIIa administration, anticoagulation and laboratory values, indications for use, dosing, ordering and administration times, concomitant blood products, and adverse events were collected. Adverse events included venous thromboembolism, stroke, myocardial infarction, and death due to systemic embolism and mortality. The primary endpoint was the utilization of rFVIIa in accordance with the off-label dosing guideline. Secondary endpoints included hemostatic efficacy of rFVIIa, adverse events, blood products administered, and cost-effectiveness of rFVIIa transition to pharmacy.

Results:

A total of 63 patients [pediatric (n = 6), adult (n = 57)] received rFVIIa, with the majority of use for refractory bleeding after cardiac surgery. The utilization of rVIIa decreased after development of the off-label dosing guideline and transition from blood bank to pharmacy. The total incidence of thromboembolic events within 30 days was 19.6%; 17.6% arterial and 2% venous; 70% of patients with an adverse event were over 70 years of age. Use of rFVIIa reduced the median number of units of blood products administered.

Conclusion:

Administration of rFVIIa for cardiac surgery appears to be effective for hemostasis. Transitioning rFVIIa from the blood bank to pharmacy and implementation of a dosing guideline appears to have reduced utilization. Patients receiving rFVIIa should be monitored for thromboembolic events. Elderly patients may be at higher risk for thromboembolic events.

Thrombin generation and bleeding in cardiac surgery: a clinical narrative review

This narrative review discusses the role of thrombin generation in coagulation and bleeding in cardiac surgery, the laboratory methods for clinical detection of impaired thrombin generation, and the available hemostatic interventions that can be used to improve thrombin generation. Coagulopathy after cardiopulmonary bypass (CPB) is associated with excessive blood loss and adverse patient outcomes. Thrombin plays a crucial role in primary hemostasis, and impaired thrombin generation can be an important cause of post-CPB coagulopathy. Existing coagulation assays have significant limitations in assessing thrombin generation, but whole-blood assays designed to measure thrombin generation at the bed-side are under development. Until then, clinicians may need to institute therapy empirically for non-surgical bleeding in the setting of normal coagulation measures. Available therapies for impaired thrombin generation include administration of plasma, prothrombin complex concentrate, and bypassing agents (recombinant activated factor VII and factor eight inhibitor bypassing activity). In vitro experiments have explored the relative potency of these therapies, but clinical studies are lacking. The potential incorporation of thrombin generation assays into clinical practice and treatment algorithms for impaired thrombin generation must await further clinical development.

Consensus Report on Patient Blood Management in Cardiac Surgery by Turkish Society of Cardiovascular Surgery (TSCVS), Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care (SCTAIC)

Anemia, transfusion and bleeding independently increase the risk of complications and mortality in cardiac surgery. The main goals of patient blood management are to treat anemia, prevent bleeding, and optimize the use of blood products during the perioperative period. The benefit of this program has been confirmed in many studies and its utilization is strongly recommended by professional organizations. This consensus report has been prepared by the authors who are the task members appointed by the Turkish Society of Cardiovascular Surgery, Turkish Society of Cardiology (TSC), and Society of Cardio-Vascular-Thoracic Anaesthesia and Intensive Care to raise the awareness of patient blood management. This report aims to summarize recommendations for all perioperative blood- conserving strategies in cardiac surgery.

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams.

Transfusion Triggers for Platelets and Other Blood Products

How to cite this article: Karanth S. Transfusion Triggers for Platelets and Other Blood Products. Indian J Crit Care Med 2019;23(Suppl 3):S189–S190.

Controversies in the Postoperative Management of the Critically Ill Heart Transplant Patient

Heart transplant recipients are susceptible to a number of complications in the immediate postoperative period. Despite advances in surgical techniques, mechanical circulatory support (MCS), and immunosuppression, evidence supporting optimal management strategies of the critically ill transplant patient is lacking on many fronts. This review identifies some of these controversies with the aim of stimulating further discussion and development into these gray areas.

Factor VII deficiency: do all need replacement for cardiac surgery?

In cardiac surgery, supplementation with recombinant factor VIIa is the treatment of choice for patients with factor VII deficiency, but overzealous administration can be associated with thromboembolic side-effects. A 53-year-old man with factor VII activity 15.2%, international normalized ratio 2.9, and acute thrombotic critical coronary anatomy, underwent coronary artery bypass surgery and a thoracotomy with decortication 5 months later. He was managed successfully without recombinant factor VIIa supplementation. This case demonstrates that current bedside and laboratory tests such as thromboelastography, prothrombin time or international normalized ratio, and factor VII activity may not predict replacement therapy in these patients.

Acquired von Willebrand syndrome in congenital heart disease surgery: results from an observational case-series

Essentials Bleeding complications during congenital heart disease surgery in neonatal age are very common. We report the perioperative incidence of acquired von Willebrand syndrome (aVWS) in 12 infants. aVWS was detected in 8 out of 12 neonates and infants intraoperatively after cardiopulmonary bypass. Ten patients received von Willebrand factor concentrate intraoperatively and tolerated it well. SUMMARY: Background Cardiac surgery of the newborn and infant with complex congenital heart disease (CHD) is associated with a high rate of intraoperative bleeding complications. CHD-related anatomic features such as valve stenoses or patent arterial ducts can lead to enhanced shear stress in the blood stream and thus cause acquired von Willebrand syndrome (aVWS). Objective To evaluate the intraoperative incidence and impact of aVWS after cardiopulmonary bypass (CPB) in neonates and infants with complex CHD. Patients/Methods We conducted a survey of patients aged < 12 months undergoing complex cardiac surgery in our tertiary referral center. Twelve patients, whose blood samples were analyzed for aVWS before CPB and immediately after discontinuation of CPB on a routine basis, were eligible for the analysis. von Willebrand factor antigen (VWF:Ag), ristocetin cofactor activity (VWF:RCo), collagen binding activity (VWF:CB), VWF:multimers and factor VIII activity (FVIII:C) were determined. Results aVWS was diagnosed by VWF multimer analysis in 10 out of 12 patients (83%) prior to surgery and intraoperatively at the end of CPB in 8 out of 12 patients (66%). Ten patients received VWF/FVIII concentrate intraoperatively as individual treatment attempts during uncontrolled bleeding. They tolerated it well without intraoperative thrombotic events. One patient suffered a transient postoperative cerebral sinuous vein thrombosis. Conclusions aVWS is of underestimated incidence in complex CHD surgery. These data may offer a new approach to reduce the risk of severe bleedings and to achieve hemostasis during high-risk pediatric cardiac surgery by tailoring the substitution with von Willebrand factor concentrate.

Prohemostatic Activity of Factor X in Combination With Activated Factor VII in Dilutional Coagulopathy

BACKGROUND

Recombinant activated factor VII (rFVIIa) concentrate reduces allogeneic blood transfusions, but it may increase thromboembolic complications in complex cardiac surgery. The mixture of activated factor VII (FVIIa) and factor X (FX) (FVIIa/FX) (FVIIa:FX = 1:10) is a novel bypassing agent for hemophilia patients. We hypothesized that the combination of FX and FVIIa could improve thrombin generation (TG) in acquired multifactorial coagulation defects such as seen in cardiac surgery and conducted in vitro evaluation of FVIIa/FX in parallel with other coagulation factor concentrates using in vitro and in vivo diluted plasma samples.

METHODS

Plasma samples were collected from 9 healthy volunteers and 12 cardiac surgical patients. We measured TG (Thrombinoscope) using in vitro 50% dilution plasma and in vivo dilution plasma after cardiopulmonary bypass, in parallel with thromboelastometry (ROTEM) and standard coagulation assays. In vitro additions of FVIIa/FX (0.35, 0.7, and 1.4 μg/mL, based on the FVIIa level), rFVIIa (1.4, 2.8, and 6.4 μg/mL), prothrombin complex concentrate (0.3 international unit), and 20% plasma replacement were evaluated.

RESULTS

In diluted plasma, the addition of either FVIIa/FX or rFVIIa shortened the lag time and increased the peak TG, but the effect in lag time of FVIIa/FX at 0.35 μg/mL was more extensive than rFVIIa at 6.4 μg/mL. Prothrombin complex concentrate increased peak TG by increasing the prothrombin level but failed to shorten the lag time. No improvement in any of the TG variables was observed after 20% volume replacement with plasma. The addition of factor concentrates normalized prothrombin time/international normalized ratio but not with plasma replacement. In cardiac patients, similar patterns were observed on TG in post-cardiopulmonary bypass samples. FVIIa/FX shortened clotting time (CT) in a concentration-dependent manner on CT on thromboelastometry. Plasma replacement did not improve CT, but a combination of plasma and FVIIa/FX (0.35 μg/mL) more effectively shortened CT than FVIIa/FX alone.

CONCLUSIONS

The combination of FVIIa and FX improved TG more efficiently than rFVIIa alone or plasma in dilutional coagulopathy models. The required FVIIa dose in FVIIa/FX was considerably lower than those reported during bypassing therapy in hemophilia patients (1.4-2.8 μg/mL). The combination of plasma could restore coagulation more efficiently compared to FVIIa/FX alone. Lesser FVIIa requirement to exert procoagulant activity may be favorable in terms of reducing systemic thromboembolic complications.

Perioperative management of the bleeding patient

Perioperative bleeding remains a major complication during and after surgery, resulting in increased morbidity and mortality. The principal causes of non-vascular sources of haemostatic perioperative bleeding are a preexisting undetected bleeding disorder, the nature of the operation itself, or acquired coagulation abnormalities secondary to haemorrhage, haemodilution, or haemostatic factor consumption. In the bleeding patient, standard therapeutic approaches include allogeneic blood product administration, concomitant pharmacologic agents, and increasing application of purified and recombinant haemostatic factors. Multiple haemostatic changes occur perioperatively after trauma and complex surgical procedures including cardiac surgery and liver transplantation. Novel strategies for both prophylaxis and therapy of perioperative bleeding include tranexamic acid, desmopressin, fibrinogen and prothrombin complex concentrates. Point-of-care patient testing using thromboelastography, rotational thromboelastometry, and platelet function assays has allowed for more detailed assessment of specific targeted therapy for haemostasis. Strategic multimodal management is needed to improve management, reduce allogeneic blood product administration, and minimize associated risks related to transfusion.

Evaluation of the real-world impact of rotational thromboelastometry-guided transfusion protocol in patients undergoing proximal aortic surgery

BACKGROUND

Complex aortic procedures are potentially associated with important blood loss and coagulopathy. The aim of this study was to assess the impact of rotational thromboelastometry (ROTEM, Tem International GmBH, Munich, Germany) on transfusion requirements after proximal aortic operations in a real-world setting.

METHODS

This single-center retrospective analysis based on 385 consecutive patients undergoing cardiac surgeries involving the aortic root, ascending aorta, or aortic arch compared 197 controls managed according to routine transfusion protocol before the introduction of the ROTEM in 2012 with 188 patients operated afterward. With the use of a 1:1 propensity score match, 224 patients were included in paired analysis (112 in each group). The primary end point was erythrocytes transfusion rate. The secondary end points comprised the transfusion of other allogeneic blood products, number of units transfused, postoperative blood loss, massive transfusion rate, and use of other hemostatic products.

RESULTS

ROTEM implementation was associated with a trend toward reduction in the rate of erythrocytes transfusion (57% vs 46%, P = .08) and a decreased median number of units transfused for erythrocytes (1.0 [0.0-4.0] unit vs 0.0 [0.0-2.0] unit, P = .03) and plasma (0.0 [0.0-4.0] unit vs 0.0 [0.0-2.0] unit, P = .04). After sensitivity analysis, ROTEM displayed a comparable rate of erythrocytes transfusion (58% vs 47%, P = .15).

CONCLUSIONS

In a real-world setting, ROTEM-based algorithm implementation could help reduce excess erythrocytes transfusion for complex aortic procedures. We advocate for a strict adherence and concerted team effort to maximize the benefits of such addition to patients' management.