The use of recombinant activated factor VII to reverse warfarin-induced anticoagulation in patients with hemorrhages in the central nervous system: preliminary findings

Guidelines for the Management of Spontaneous Intracerebral Hemorrhage: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of spontaneous intracerebral hemorrhage.

METHODS

A formal literature search of PubMed was performed through the end of August 2013. The writing committee met by teleconference to discuss narrative text and recommendations. Recommendations follow the American Heart Association/American Stroke Association methods of classifying the level of certainty of the treatment effect and the class of evidence. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Oversight Committee and Stroke Council Leadership Committee.

RESULTS

Evidence-based guidelines are presented for the care of patients with acute intracerebral hemorrhage. Topics focused on diagnosis, management of coagulopathy and blood pressure, prevention and control of secondary brain injury and intracranial pressure, the role of surgery, outcome prediction, rehabilitation, secondary prevention, and future considerations. Results of new phase 3 trials were incorporated.

CONCLUSIONS

Intracerebral hemorrhage remains a serious condition for which early aggressive care is warranted. These guidelines provide a framework for goal-directed treatment of the patient with intracerebral hemorrhage.

Comparison of 3-Factor Prothrombin Complex Concentrate and Low-Dose Recombinant Factor VIIa for Warfarin Reversal

Introduction

Prothrombin complex concentrate (PCC) and recombinant Factor VIIa (rFVIIa) have been used for emergent reversal of warfarin anticoagulation. Few clinical studies have compared these agents in warfarin reversal. We compared warfarin reversal in patients who received either 3 factor PCC (PCC3) or low-dose rFVIIa (LDrFVIIa) for reversal of warfarin anticoagulation.

Methods

Data were collected from medical charts of patients who received at least one dose of PCC3 (20 units/kg) or LDrFVIIa (1000 or 1200 mcg) for emergent warfarin reversal from August 2007 to October 2011. The primary end-points were achievement of an INR 1.5 or less for efficacy and thromboembolic events for safety.

Results

Seventy-four PCC3 and 32 LDrFVIIa patients were analyzed. Baseline demographics, reason for warfarin reversal, and initial INR were equivalent. There was no difference in the use of vitamin K or fresh frozen plasma. More LDrFVIIa patients achieved an INR of 1.5 or less (71.9% vs. 33.8%, p =0.001). The follow-up INR was lower after LDrFVIIa (1.25 vs. 1.75, p < 0.05) and the percent change in INR was larger after LDrFVIIa (54.1% vs. 38.8%, p = 0.002). There was no difference in the number of thromboembolic events (2 LDrFVIIa vs. 5 PCC3, p = 1.00), mortality, length of hospital stay, or cost.

Conclusions

Based on achieving a goal INR of 1.5 or less, LDrFVIIa was more likely than PCC3 to reverse warfarin anticoagulation. Thromboembolic events were equivalent in patients receiving PCC3 and LDrFVIIa.

The effects of recombinant activated factor VII dose on the incidence of thromboembolic events in patients with coagulopathic bleeding

INTRODUCTION

Previous studies have suggested the used of off-label recombinant factor VII (rFVIIa) increases the risk of thromboembolic events, but the effect of the dose of rFVIIa is not well described in the literature.

MATERIALS AND METHODS

All adult patients that received off-label rFVIIa from 2005-2012 were included in this single-center, retrospective cohort study. The primary endpoint was the incidence of a thromboembolic event in the low dose (<50 mcg/kg) compared to the high dose (≥50 mcg/kg) cohort. Secondary endpoints compared time to thromboembolic event, incidence of arterial compared to venous events, and mortality.

RESULTS

There were 152 patients that received rFVIIa during the study period with 66 in the low dose cohort and 86 in the high dose cohort. Mean total dose of rFVIIa was 30.2 mcg/kg (SD ± 9.5 mcg/kg) in the low dose and 99.8 mcg/kg (SD ± 64.7 mcg/kg) in the high dose cohort (p=0.0001). The overall incidence of thromboembolic events was 12.5%. There were 12 (14%) events in the low dose cohort and seven (10.6%) in the high dose cohort, RR=0.76 (95% CI 0.31-1.82). There were no differences in any of the secondary outcomes. A higher incidence of thromboembolic events in cardiothoracic surgery (20.8%) and penetrating trauma patients (21.4%) was seen compared to the remaining cohort (6.7%).

CONCLUSIONS

No significant difference in the incidence of thromboembolic events was seen between low dose versus high dose rFVIIa over a seven year period at our institution. However, due to the relatively low overall incidence and a small sample size, type II error may be present.

Novel Oral Anticoagulants: A Focused Review for Stroke Physicians

Novel oral anticoagulants provide an effective and convenient alternative to warfarin for stroke prevention in patients with atrial fibrillation. However, novel anticoagulants also present new challenges for stroke physicians, such as measurement of anticoagulant effect in emergency situations, use of thrombolysis in acute ischemic stroke, optimal timing of introduction of novel anticoagulants following acute ischemic stroke, and management of intracerebral hemorrhage. In this review, we propose pragmatic approaches to dealing with challenging management issues that will face stroke physicians who care for patients with acute stroke in the novel oral anticoagulant era.

Rapid reversal of warfarin-associated hemorrhage in the emergency department by prothrombin complex concentrates

Life-threatening warfarin-associated hemorrhage is common, with a high mortality. In the United States, the most commonly used therapies--fresh frozen plasma and vitamin K--are slow and unpredictable and can result in volume overload. Outside of the United States, prothrombin complex concentrates are often used instead; these pooled plasma products reverse warfarin anticoagulation in minutes rather than hours. This article reviews the literature relating to warfarin reversal with fresh frozen plasma, prothrombin complex concentrates, and recombinant factor VIIa and provides elements for a management protocol based on this literature.

Current State of Knowledge on Oral Anticoagulant Reversal Using Procoagulant Factors

OBJECTIVE:

To discuss current trends and challenges in the use of procoagulants for treating bleeding caused by use of oral anticoagulants.

DATA SOURCES:

Literature searches of PubMed (MEDLINE), Google, and Medscape were conducted in February 2013. There were no date limitations. Search terms included anticoagulation agents, anticoagulation reversal, anticoagulation reversal agents, apixaban, clinical studies, dabigatran, 3-factor PCCs, 4-factor PCCs, FEIBA, fresh frozen plasma, human studies, pharmacology, prescribing information, rFVIIa, rivaroxaban, vitamin K, and warfarin.

DATA SYNTHESIS:

Warfarin has been the mainstay for the treatment and prevention of primary and secondary thrombosis in patients with cardiovascular disorders such as atrial fibrillation, deep vein thrombosis, pulmonary embolism, and stroke. Three oral anticoagulants have recently become available in the US: a direct thrombin inhibitor, dabigatran etexilate, and 2 direct factor Xa inhibitors, rivaroxaban and apixaban. Reversal strategies for anticoagulant-associated bleeding are well established for warfarin; however, strategies to stop bleeding in a patient who has taken one of the newer anticoagulants are less clear. In the US, agents available for oral anticoagulant reversal include activated prothrombin complex concentrate (APCC), 3-factor PCCs, and recombinant activated factor VII (rFVIIa). Few studies have evaluated the 3-factor PCCs, and current evidence for APCC and rFVIIa as reversal agents for dabigatran and rivaroxaban is based primarily on laboratory or animal studies, or on small studies in healthy humans and case reports.

CONCLUSIONS:

Patients contemplating using the new oral anticoagulants should be informed about specific clinical situations that could pose a bleeding risk such as the need for emergency surgery because no reliable antidote is available to stop the bleeding, which could prove fatal.

Reversal of oral anticoagulation

Although the use of dabigatran and rivaroxaban are increasing, data on the reversal of their effects are limited. The lack of reliable monitoring methods and specific reversal agents renders treatment strategies empirical, and as a result, treatment consists mainly of supportive measures. Therefore, we performed a systematic search of the PubMed database to find studies and reviews pertaining to oral anticoagulation reversal strategies. This review discusses current anticoagulation reversal recommendations for the oral anticoagulants warfarin, dabigatran, and rivaroxaban for patients at a heightened risk of bleeding, actively bleeding, or those in need of preprocedural anticoagulation reversal. We highlight the literature that shaped these recommendations and provide directions for future research to address knowledge gaps. Although reliable recommendations are available for anticoagulation reversal in patients treated with warfarin, guidance on the reversal of dabigatran and rivaroxaban is varied and equivocal. Given the increasing use of the newer agents, focused research is needed to identify effective reversal strategies and develop and implement an accurate method (assay) to guide reversal of the newer agents. Determining patient-specific factors that influence the effectiveness of reversal treatments and comparing the effectiveness of various treatment strategies are pertinent areas for future anticoagulation reversal research.

Controversies in neurosciences critical care

Neurocritical care is an evolving subspecialty with many controversial topics. The focus of this review is (1) transfusion thresholds in patients with acute intracranial bleeding, including packed red blood cell transfusion, platelet transfusion, and reversal of coagulopathy; (2) indications for seizure prophylaxis and choice of antiepileptic agent; and (3) the role of specialized neurocritical care units and specialists in the care of critically ill neurology and neurosurgery patients.

Evidence-based management of anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

High-quality anticoagulation management is required to keep these narrow therapeutic index medications as effective and safe as possible. This article focuses on the common important management questions for which, at a minimum, low-quality published evidence is available to guide best practices.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

Most practical clinical questions regarding the management of anticoagulation, both oral and parenteral, have not been adequately addressed by randomized trials. We found sufficient evidence for summaries of recommendations for 23 questions, of which only two are strong rather than weak recommendations. Strong recommendations include targeting an international normalized ratio of 2.0 to 3.0 for patients on vitamin K antagonist therapy (Grade 1B) and not routinely using pharmacogenetic testing for guiding doses of vitamin K antagonist (Grade 1B). Weak recommendations deal with such issues as loading doses, initiation overlap, monitoring frequency, vitamin K supplementation, patient self-management, weight and renal function adjustment of doses, dosing decision support, drug interactions to avoid, and prevention and management of bleeding complications. We also address anticoagulation management services and intensive patient education.

CONCLUSIONS

We offer guidance for many common anticoagulation-related management problems. Most anticoagulation management questions have not been adequately studied.

Management of bleeding complications in the anticoagulated patient

As new anticoagulants become available, and the number of anticoagulated patients continues to rise, it is necessary to know how to deal with associated bleeding complications. In this review, reversal strategies for traditional anticoagulants (warfarin and heparin) as well as newer anticoagulants are described. Prothrombin complex concentrates (PPCs) can be used to reverse vitamin K antagonists (VKA), and plasma may be used where they are not available. Recombinant activated factor VII (rFVIIa) may be useful to reverse pentasaccharide anticoagulants. 1-Desamino-8-D-arginine vasopressin (DDAVP), cryoprecipitate, PCCs, and dialysis may help to reverse direct thrombin inhibitors, while rFVIIa seems to be ineffective. The effect of direct factor Xa inhibitors may be reversed by PCCs, FVIIa, or factor Xa concentrates.

Emergency reversal of anticoagulation: from theory to real use of prothrombin complex concentrates. A retrospective Italian experience

BACKGROUND

Prothrombin Complex Concentrates (PCC) are administered to normalise blood coagulation in patients receiving oral anticoagulant therapy (OAT). Rapid reversal of OAT is essential in case of major bleeding, internal haemorrhage or surgery.The primary end-point was to evaluate whether PCC in our hospital were being used in compliance with international and national guidelines for the reversal of OAT on an emergency basis. The secondary end-point was to evaluate the efficacy and safety of PCC.

MATERIALS AND METHODS

All patients receiving OAT who required rapid reversal anticoagulation because they had to undergo emergency surgery or urgent invasive techniques following an overdose of oral anticoagulants were eligible for this retrospective observational study.

RESULTS

Forty-seven patients receiving OAT who needed rapid reverse of anticoagulation were enrolled in our study. The patients were divided in two groups: (i) group A (n=23), patients needed haemostatic treatment before neurosurgery after a head injury and (ii) group B (n=24), patients with critical haemorrhage because of an overdose of oral anticoagulants. The International Normalised Ratio (INR) was checked before and after infusion of the PCC. The mean INR in group A was 2.7 before and 1.43 after infusion of the PCC; in group B the mean INR of 6.58, before and 1.92 after drug infusion. The use of vitamin K, fresh-frozen plasma and red blood cells was also considered. During our study 22 patients died, but no adverse effects following PCC administration were recorded.

DISCUSSION

In our study three-factor-PCC was found to be effective and safe in rapidly reversing the effects of OAT, although it was not always administered in accordance with international or national guidelines. The dose, time of administration and monitoring often differed from those recommended. In the light of these findings, we advocate the use of single standard protocol to guide the correct use of PCC in each hospital ward.

The surgical management of chronic subdural hematoma

Chronic subdural hematoma (cSDH) is an increasingly common neurological disease process. Despite the wide prevalence of cSDH, there remains a lack of consensus regarding numerous aspects of its clinical management. We provide an overview of the epidemiology and pathophysiology of cSDH and discuss several controversial management issues, including the timing of post-operative resumption of anticoagulant medications, the effectiveness of anti-epileptic prophylaxis, protocols for mobilization following evacuation of cSDH, as well as the comparative effectiveness of the various techniques of surgical evacuation. A PubMed search was carried out through October 19, 2010 using the following keywords: "subdural hematoma", "craniotomy", "burr-hole", "management", "anticoagulation", "seizure prophylaxis", "antiplatelet", "mobilization", and "surgical evacuation", alone and in combination. Relevant articles were identified and back-referenced to yield additional papers. A meta-analysis was then performed comparing the efficacy and complications associated with the various methods of cSDH evacuation. There is general agreement that significant coagulopathy should be reversed expeditiously in patients presenting with cSDH. Although protocols for gradual resumption of anti-coagulation for prophylaxis of venous thrombosis may be derived from guidelines for other neurosurgical procedures, further prospective study is necessary to determine the optimal time to restart full-dose anti-coagulation in the setting of recently drained cSDH. There is also conflicting evidence to support seizure prophylaxis in patients with cSDH, although the existing literature supports prophylaxis in patients who are at a higher risk for seizures. The published data regarding surgical technique for cSDH supports primary twist drill craniostomy (TDC) drainage at the bedside for patients who are high-risk surgical candidates with non-septated cSDH and craniotomy as a first-line evacuation technique for cSDH with significant membranes. Larger prospective studies addressing these aspects of cSDH management are necessary to establish definitive recommendations.

Treatment of warfarin-related intracranial hemorrhage: a comparison of prothrombin complex concentrate and recombinant activated factor VII

OBJECTIVE

Warfarin-related intracranial hemorrhage (ICH) is a devastating complication of warfarin therapy. Several studies have demonstrated successful correction of the international normalized ratio (INR) using prothrombin complex concentrate (PCC) or recombinant activated factor VII (rFVIIa). To our knowledge, no study has directly compared these agents for treatment of warfarin-related ICH.

METHODS

We retrospectively reviewed the charts of 15 patients who received rFVIIa and 9 who received PCC for treatment of warfarin-related ICH over a 2-year period. The primary objective was to compare the efficacy of rFVIIa and PCC in correcting the INR to 1.3 or less. Baseline INR was compared to INR obtained within 1, 3, 6, 12, and 24 hours after rFVIIa or PCC administration.

RESULTS

Six patients in the rFVIIa group and five in the PCC group had a follow-up INR within 1 hour of agent administration. In the rFVIIa group, the mean INR decreased from 6.1 to 1.1 and from 2.3 to 1.48 in the PCC group. At 6 hours, all rFVIIa patients and six (67%) PCC patients had at least one subsequent INR, with 93% and 50% correcting to an INR of 1.3 or less. Mean dose for all patients included was 53.4 ± 17.5 μg/kg and 27.8 ± 15.4 units/kg for rFVIIa and PCC, respectively.

CONCLUSION

Correction of the INR is more reliably obtained with rFVIIa when compared to PCC. Larger, prospective studies comparing these therapies for warfarin-related ICH are needed.

How I treat warfarin-associated coagulopathy in patients with intracerebral hemorrhage

Intracerebral hemorrhage in patients with warfarin-associated coagulopathy is an increasingly common life-threatening condition that requires emergent management. The evolution of therapeutic options in this setting, as well as recently published guidelines, has resulted in some heterogeneity in recommendations by professional societies. This heterogeneity can be attributed to lack of evidence-based support for plasma therapy; the variability in availability of prothrombin complex concentrates; the variability in the coagulation factor levels and contents of prothrombin complex concentrates; ambiguity about the optimal dose and route of administration of vitamin K; and the lack of standardized clinical care pathways, particularly in community hospitals, for the management of these critical care patients. In this review, we summarize the relevant literature about these controversies and present recommendations for management of patients with warfarin-associated coagulopathy and intracerebral hemorrhage.

Recombinant Factor VIIa: An Assessment of Evidence Regarding Its Efficacy and Safety in the Off-Label Setting

Recombinant human factor VIIa (rFVIIa) is approved by the US Food and Drug Administration for use in the setting of hemorrhage associated with factor VIII or factor IX inhibitors in patients with congenital or acquired hemophilia. This indication represents only a small number of bleeding conditions. Since it became available, rFVIIa has been increasingly used in the management of off-label indications, ranging from emergent hemostasis in traumatic hemorrhage to prophylactic hemostasis in patients undergoing major surgery. Prominent off-label indications include the management of patients with coagulopathies, such as occurs in trauma patients experiencing massive and uncontrolled hemorrhage, and in patients undergoing cardiovascular surgery with cardiopulmonary bypass. Other occasions for use occur in patients with intact coagulation systems, with nontraumatic intracranial hemorrhage being the most common in this group. Uncertainties regarding the efficacy and safety associated with use of rFVIIa in these off-label scenarios have led to evidence-based assessments of patient outcomes, including mortality, the rate of thromboembolic adverse events, and posttreatment functional status. We review the evidence regarding the efficacy and safety of this important, but controversial, hemostatic agent in the off-label setting.

Exploratory study on the reversal of warfarin with rFVIIa in healthy subjects

The use of warfarin has a well-known bleeding risk. Recombinant activated factor VII (rFVIIa) is a non–plasma-derived, rapid-acting, and rapidly infused potential treatment. This randomized, single-center, placebo-controlled, double-blinded, dose-escalation, exploratory phase 1 trial assessed safety and effects of rFVIIa in reversing warfarin-induced changes in bleeding and coagulation parameters, using a punch biopsy–induced bleeding model in healthy subjects. The effects of warfarin (experiment 1) and rFVIIa (5-80 μg/kg; experiment 2) were evaluated. Outcomes were bleeding duration, blood loss, coagulation parameters, and safety. Warfarin treatment significantly increased bleeding duration and blood loss from pretreatment (experiment 1, 12 subjects). However, these parameters after rFVIIa treatment were not significantly different from placebo (experiment 2, 85 subjects). Mean activated partial thromboplastin time, prothrombin time, and international normalized ratio were reduced from warfarin-elevated levels. rFVIIa (80 μg/kg) significantly reversed warfarin effects on all thromboelastography parameters, compared with placebo (P < .05), and returned the thrombin generation speed to baseline. There were no thromboembolic or serious adverse events. In this exploratory trial, the reversal of warfarin effects was observed in the thromboelastography, thrombin generation, and clotting assays. However, this reversal did not translate to improvements in the bleeding model parameters evaluated in the punch biopsy model. Trial registration is exempt (phase 1).

Guidelines for the management of spontaneous intracerebral hemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

PURPOSE

The aim of this guideline is to present current and comprehensive recommendations for the diagnosis and treatment of acute spontaneous intracerebral hemorrhage.

METHODS

A formal literature search of MEDLINE was performed. Data were synthesized with the use of evidence tables. Writing committee members met by teleconference to discuss data-derived recommendations. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation. Prerelease review of the draft guideline was performed by 6 expert peer reviewers and by the members of the Stroke Council Scientific Statements Oversight Committee and Stroke Council Leadership Committee. It is intended that this guideline be fully updated in 3 years' time.

RESULTS

Evidence-based guidelines are presented for the care of patients presenting with intracerebral hemorrhage. The focus was subdivided into diagnosis, hemostasis, blood pressure management, inpatient and nursing management, preventing medical comorbidities, surgical treatment, outcome prediction, rehabilitation, prevention of recurrence, and future considerations.

CONCLUSIONS

Intracerebral hemorrhage is a serious medical condition for which outcome can be impacted by early, aggressive care. The guidelines offer a framework for goal-directed treatment of the patient with intracerebral hemorrhage.

French clinical practice guidelines on the management of patients on vitamin K antagonists in at-risk situations (overdose, risk of bleeding, and active bleeding)

The present report from several French medical societies in the field and the French National Authority for Health provides an expert consensus for the management of patients on vitamin K antagonists in at-risk situations (overdose, risk of bleeding, and active bleeding). Asymptomatic VKA overdose is defined as an International Normalized Ratio (INR) value above the upper limit of the therapeutic target. In this case, the guidelines describe the rapid reduction of the INR down to the therapeutic range, either by omitting a dose or using vitamin K. Regarding the haemorrhagic complications, the guidelines address the management of these patients according to the severity of bleeding, and especially focus on the use of prothrombin complex concentrate. Finally, the consensus addresses the management of patients in cases of elective or emergency surgery or other invasive procedures, and discusses whether treatment should be continued or not, and whether VKA substitution by heparin--"bridging anticoagulation"--is needed.

Safety of recombinant activated factor VII in patients with warfarin-associated hemorrhages of the central nervous system

BACKGROUND AND PURPOSE

Recombinant Factor VIIa decreases hematoma growth after spontaneous intracerebral hemorrhage (ICH) and rapidly decreases international normalized ratios in patients on warfarin but is also associated with an increased risk for thromboembolic complications. In this study, we assessed the risk of thromboembolic events in patients receiving recombinant Factor VIIa after ICH associated with warfarin treatment.

METHODS

We reviewed the medical charts, laboratory data, and radiological findings of consecutive patients with anticoagulation-related hemorrhages of the central nervous system who received recombinant Factor VIIa at Mayo Clinic Rochester and Mayo Clinic Florida between 2002 and 2009. The primary end point was the frequency of new thromboembolic events, including myocardial infarction, deep vein thrombosis, ischemic stroke, and pulmonary embolism.

RESULTS

We identified 101 patients; 54% had ICH and 30% subdural hematomas. The most common indications for anticoagulation were atrial fibrillation, deep vein thrombosis, and prosthetic valve. Thirteen patients (12.8%) had new thromboembolic events (10 deep vein thromboses and 3 ischemic strokes) within 90 days after recombinant Factor VIIa administration. Eight of these adverse events occurred within 2 weeks of treatment. In patients with ICH, the rate of thromboembolic complications was 5% and all events were venous.

CONCLUSIONS

The risk of thromboembolic events in patients who received recombinant Factor VIIa for anticoagulation-associated ICH was not higher than that seen in patients treated for spontaneous ICH in the Factor Seven for Acute Hemorrhagic Stroke (FAST) trial. Spontaneous deep vein thrombosis was the most common complication in our series.

Controversies of Anticoagulation Reversal in Life-Threatening Bleeds

Therapeutic anticoagulation with heparins, warfarin, and anti-Xa inhibitors carry an inherent risk of complications due to their multifaceted pharmacokinetic and pharmacodynamic properties as well as narrow therapeutic ranges. When an anticoagulated patient presents with a major or life-threatening bleed, immediate and effective therapy may be necessary to reverse the effects of the anticoagulant, minimize blood loss, and reduce patient morbidity and mortality. Optimal agents and strategies for anticoagulant reversal are limited, particularly for newer anticoagulants. The literature describing such strategies available to reverse the effects of anticoagulants in the setting of a bleed is limited, and therefore many controversies exist. Thus, as new anticoagulants become available, without a specific agent for reversal, the concerns and controversies related to this topic must be addressed. The purpose of this review is to discuss the management of major or life-threatening bleeds by addressing the following controversies: (1) the use of recombinant factor VIIa for rapid reversal of warfarin in patients with intracerebral hemorrhage, (2) the role of prothrombin complex concentrate in emergent warfarin reversal, and (3) the optimal approach to reverse newer anticoagulants such as low molecular weight heparins, fondaparinux, and direct thrombin inhibitors.

Management of acute intracranial and intraventricular hemorrhage

OBJECTIVE

Acute intracranial hemorrhage and intraventricular hemorrhage are devastating disorders. The goal of this review is to familiarize clinicians with recent information pertaining to the acute care of intracranial hemorrhage and intraventricular hemorrhage.

DATA SOURCES

PubMed search and review of the relevant medical literature.

SUMMARY

The management of intracranial hemorrhage and intraventricular hemorrhage is complex. Effective treatment should include strategies designed to reduce hematoma expansion and limit the medical consequences of intracranial hemorrhage and intraventricular hemorrhage. At present, there are a number of new approaches to treatment that may reduce mortality and improve clinical outcomes. Clinicians should recognize that patients with large hematomas may make a substantial recovery.

CONCLUSIONS

Patients with intracranial hemorrhage and intraventricular hemorrhage should be cared for in an intensive care unit. New therapies designed to stabilize hematoma growth and reduce hematoma burden may improve outcomes.

The efficacy of factor VIIa in emergency department patients with warfarin use and traumatic intracranial hemorrhage

OBJECTIVES

The objective was to compare outcomes in emergency department (ED) patients with preinjury warfarin use and traumatic intracranial hemorrhage (tICH) who did and did not receive recombinant activated factor VIIa (rFVIIa) for international normalized ratio (INR) reversal.

METHODS

This was a retrospective before-and-after study conducted at a Level 1 trauma center, with data from 1999 to 2009. Eligible patients had preinjury warfarin use and tICH on cranial computed tomography (CT) scan. Patients before (standard cohort) and after (rFVIIa cohort) implementation of a protocol for administering 1.2 mg of rFVIIa in the ED were reviewed. Glasgow Coma Scale (GCS) score, Revised Trauma Score (RTS), Injury Severity Score (ISS), INR, and Marshall score were collected. Outcome measures included mortality, thromboembolic complications, and INR normalization.

RESULTS

Forty patients (median age=80.5 years, interquartile range [IQR]=63.5-85) were included (20 in each cohort). Age, GCS score, ISS, RTS, initial INR, and Marshall score were similar (p>0.05) between the two cohorts. Survival was identical between cohorts (13 of 20, or 65.0%, 95% confidence interval [CI]=40.8% to 84.6%). There were no differences in rate of thromboembolic complications in the standard cohort (1 of 20, 5.0%, 95% CI=0.1% to 24.9%) than the rFVIIa cohort (4 of 20, 20.0%, 95% CI=5.7% to 43.7%; p=0.34). Time to normal INR was earlier in the rFVIIa cohort (mean=4.8 hours, 95% CI=3.0 to 6.7 hours) than in the standard cohort (mean=17.5 hours, 95% CI=12.5 to 22.6; p<0.001).

CONCLUSIONS

In patients with preinjury warfarin and tICH, use of rFVIIa was associated with a decreased time to normal INR. However, no difference in mortality was identified. Use of rFVIIa in patients on warfarin and tICH requires further study to demonstrate important patient-oriented outcomes.

Complications of recombinant activated human coagulation factor VII

BACKGROUND

Recombinant factor VIIa (rFVIIa) frequently is used for treatment of life-threatening hemorrhage in trauma.

METHODS

A retrospective review of injured patients receiving rFVIIa at an American College of Surgeons-verified Level 1 trauma center was performed. Controls were matched for age, sex, Injury Severity Score, and traumatic brain injury. Thrombotic complications in patients administered rFVIIa, including deep venous thrombosis (DVT), pulmonary embolus, acute myocardial infarction, ischemic stroke, mesenteric ischemia, arterial thromboembolism, and death, were determined.

RESULTS

Thirty-six patients were given rFVIIa, of whom 5 (13.8%) had thrombotic complications. Indications for rFVIIa were life-threatening intracranial bleeding in the presence of pre-injury anticoagulation or hemorrhage. The incidences of DVT (n = 4) and acute myocardial infarction (n = 1) were noted. In the control group, there were fewer thrombotic complications (DVT, 1; pulmonary embolus, 1). The mortality rate (52.8%) was higher in patients receiving rFVIIa compared with the control group (22.2%; P = .014). Pre-injury anticoagulation was common in the treatment group.

CONCLUSIONS

Pre-injury anticoagulation is frequently the indication for rFVIIa administration. Thrombotic complications occur with rFVIIa administration. The mortality rate of injured patients who receive rFVIIa is high.

Hemostatic and hemorrhagic problems in neurosurgical patients

BACKGROUND

Abnormalities of the hemostasis can lead to hemorrhage, and on the other hand to thrombosis. Intracranial neoplasms, complex surgical procedures, and head injury have a specific impact on coagulation and fibrinolysis. Moreover, the number of neurosurgical patients on medication (which interferes with platelet function and/or the coagulation systems) has increased over the past years.

METHOD

The objective of this review is to recall common hemostatic disorders in neurosurgical patients on the basis of the "new concept of hemostasis". Therefore the pertinent literature was searched to provide a structured and up to date manuscript about hemostasis in Neurosurgery.

FINDINGS

According to recent scientific publications abnormalities of the coagulation system are discussed. Pathophysiological background and the rational for specific (cost)-effective perioperative hemostatic therapy is provided.

CONCLUSIONS

Perturbations of hemostasis can be multifactorial and maybe encountered in the daily practice of neurosurgery. Early diagnosis and specific treatment is the prerequisite for successful treatment and good patients outcome.

Management and outcome of patients with acute traumatic subdural hematomas and pre-injury oral anticoagulation therapy

BACKGROUND

Acute subdural hematomas (aSDHs) are found in up to one-third of patients with severe traumatic brain injury and are associated with an unfavorable outcome in the majority of cases. Mortality ranges between 40 and 60%, but was reported to be even higher in patients undergoing oral anticoagulation therapy (OAT) at the time of injury. The objective of this study is to specifically report on the peri-operative management and outcome of patients with aSDH and pre-injury OAT.

MATERIAL AND METHODS

From June 2002 to June 2006, all patients with OAT who underwent surgical treatment of aSDH were retrospectively analysed. Results of pre-operative blood tests, the peri-operative and surgical management and the clinical courses were assessed. Patient outcome is reported according to the Glasgow Outcome Scale (GOS) at 6 months.

RESULTS

Eleven (10.3%) out of 107 patients with aSDH were on OAT. Patients with OAT were significantly older than patients without OAT (72.4 +/- 9.3 versus 59.9 +/- 17.5 years; p<0.05, Mann-Whitney U-test). Intensity of head trauma was moderate in four and severe in seven patients with a median pre-operative Glasgow Coma Scale (GCS) of 8. Median pre-treatment prothrombin time and international normalized ratio were 23% (range: 10-65%) and 3.3 (range: 1.5-10.6), respectively. Replacement therapy consisted of administration of prothrombin complex concentrates, vitamin K and FFP (fresh frozen plasma). In four patients, antithrombin was additionally given to prevent disseminated intravascular coagulation. Surgical treatment consisted of craniotomy (n=10) or craniectomy (n=1) and hematoma evacuation with intracranial pressure probe placement. Low molecular weight heparin was administered as pharmacological prophylaxis of thrombembolic events in an increasing dose post-operatively. At 6 months, six out of 11 patients survived with a median GOS of 4. All-cause mortality was 45.5%. A pre-operative GCS of < or = 8 was not associated with an increased risk of mortality (p>0.5, Fisher's exact test). No relevant rebleedings or thrombembolic complications were observed. The mortality rate of patients who did not undergo OAT was 50%.

CONCLUSION

A large number of patients with aSDH are on pre-injury OAT. Specific replacement therapy facilitates successful clot evacuation without bleeding complications. The overall outcome of these patients does not seem to differ from historical cohorts with aSDH without OAT, but a large prospective multicenter study is warranted to answer that question.

Bench-to-bedside review: Optimising emergency reversal of vitamin K antagonists in severe haemorrhage - from theory to practice

Critical care physicians are increasingly facing patients receiving oral anticoagulation for either cessation of major haemorrhage or to reverse the effects of vitamin K antagonists ahead of emergency surgery. Rapid reversal of anticoagulation is particularly essential in cases of life-threatening bleeding. In these situations, guidelines recommend the concomitant administration of prothrombin complex concentrates (PCCs) and oral or intravenous vitamin K for the fastest normalisation of the international normalised ratio (INR). Despite their universal recommendation, PCCs remain underused by many physicians who prefer to opt for fresh frozen plasma despite its limitations in anticoagulant reversal, including time to reverse INR and high risk of transfusion-related acute lung injury. In contrast, the lower volume required to normalise INR with PCCs and the room temperature storage facilitate faster preparation and administration time, thus increasing the speed at which haemorrhages can be treated. PCCs therefore allow faster, more reliable and complete reversal of vitamin K anticoagulation, especially when administered immediately following confirmation of haemorrhage. In the emergency setting, probabilistic dosing may be considered.

Anticoagulants in coronary artery disease

Anticoagulant therapy for acute coronary syndromes is becoming more complex as newer agents are added to unfractionated heparin and warfarin. The anticoagulants used in current clinical practice are low molecular weight heparins, direct thrombin inhibitors, and heparinoids. Properties of and recent clinical trial data regarding these newer anticoagulants are reviewed in reference to current American College of Cardiology/American Heart Association guidelines.

Reversal of coagulopathy in critically ill patients with traumatic brain injury: recombinant factor VIIa is more cost-effective than plasma

BACKGROUND

Traumatic brain injury (TBI) is the leading cause of death and disability after trauma. Coagulopathy is common in this patient population and requires rapid reversal to allow for safe neurosurgical intervention and prevent worsening of the primary injury. Typically reversal of coagulopathy is accomplished with the use of plasma. Recombinant factor VIIa (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) has become increasingly used "off-label" in patients with neurosurgical emergencies to rapidly reverse coagulopathy. We hypothesized that the use of rFVIIa in this patient population would prove to be cost-effective as well as demonstrate clinical benefit.

METHODS

The trauma registry at the R Adams Cowley Shock Trauma Center was used to identify all coagulopatic trauma patients admitted between January 2002 and December 2007 with relatively isolated TBI (head Abbreviated Injury Scale score of >or=4). The medical records of patients were reviewed and demographics, injury-specific data, medications administered, laboratory values, blood product utilization, neurosurgical procedures, length of stay (LOS), discharge disposition, and outcome data were abstracted. Patients who received rFVIIa for reversal of coagulopathy were compared against those who did not receive rFVIIa. t Tests were used to compare differences between continuous variables, and chi2 analysis was used to compare categorical variables. A p value of <0.05 was considered significant for all statistical tests.

RESULTS

During a 6-year period, there were 179 patients who met inclusion criteria. One hundred eleven patients (62.0%) were treated with conventional therapy alone whereas 68 (38.0%) received rFVIIa. Baseline characteristics between the two groups were similar except that Injury Severity Score and admission International normalized ratio were higher in the rFVIIa group and the rFVIIa group had a higher percentage of patients with head Abbreviated Injury Scale score of 5 injuries, patients who underwent neurosurgical procedures and patients with preinjury warfarin use. There was no difference in total charges between these groups (mean US $63,403 in the conventionally treated group vs. $66,086). When patients who required admission to the intensive care unit were analyzed (n = 110, 50% received rFVIIa), total mean charges and costs were significantly lower in the group that received rFVIIa (mean US $108,900 vs. $77,907). Hospital LOS, days of mechanical ventilation, and plasma utilization were lower in the rFVIIa group. Mortality and thromboembolic complication rates were not different between the two groups.

CONCLUSION

In this study, we were able to demonstrate a significant economic benefit of the use of rFVIIa for reversal of coagulopathy in severely injured patients with TBI. Not all patients with coagulopathy and an anatomic brain injury benefit, but in patients who are neurologically or physiologically compromised, using rFVIIa decreases total charges and costs of hospitalization. This decrease in overall cost is directly attributable to the significant decrease in LOS and decrease in the need for mechanical ventilation. This study demonstrates that in coagulopathic patients with TBI who require intensive care unit admission, rFVIIa is cost-effective and safe. Prospective studies are needed to confirm these findings and establish clinical effectiveness.

Warfarin reversal in anticoagulant-associated intracerebral hemorrhage

Anticoagulant-associated intracerebral hemorrhage (ICH) is a devastating disease, causing death in half of patients and permanent disability in the majority of survivors. The finding that patients often continue bleeding after hospital presentation offers the possibility that emergency warfarin reversal may improve outcomes. As no clinical trials have demonstrated the superiority of any one treatment strategy, various treatment options are available. Intravenous vitamin K is the definitive therapy; however, as monotherapy it can require many hours to take effect. Therefore, it is often considered an adjunct agent. Coagulation factors can be repleted with fresh frozen plasma (FFP), which is widely available and relatively low cost, but can require substantial time to deliver in real-world settings. A number of coagulation factor products collectively termed prothrombin complex concentrates (PCCs) are widely available that can rapidly provide many or all the vitamin K-dependent coagulation factors. Recombinant activated factor VII is used in many centers for this purpose, as it is thought to provide a procoagulant effect that may compensate for the lack of the other critical factors. Until clinical trials demonstrate the superiority of any one means of warfarin reversal, a number of expert guidelines from national organizations are available to help local providers guide therapy. At our institution, we have focused on improving the rapid and reliable delivery of a combination of intravenous vitamin K and FFP, with continued re-dosing until the desired INR lowering is achieved.

Recombinant factor VIIa for warfarin-associated intracranial bleeding

STUDY OBJECTIVE

To examine the efficacy of recombinant factor VIIa (rVIIa) in reversing warfarin-induced coagulopathy in trauma patients presenting with intracranial hemorrhage (ICH).

DESIGN

Retrospective, cohort-controlled database review.

SETTING

Level 1, university-affiliated trauma center.

PATIENTS

54 patients presenting with ICH associated with chronic warfarin therapy, 30 of whom were treated with rVIIa, and the other 24 patients treated conventionally.

MEASUREMENTS

We examined initial and subsequent coagulation studies (prothrombin time, international normalized ratio [INR]), blood product requirement, and clinical outcome, including time to reverse anticoagulation, duration of reversal, and subsequent mortality.

MAIN RESULTS

Patients treated with rVIIa required significantly less plasma (4 vs 7 units) to correct their INR, and corrected in a much shorter period of time (2.4 vs 10 hrs). The duration of corrected INR after rVIIa was dose-dependent.

CONCLUSIONS

Factor rVIIa provides prompt correction of the INR of dose-dependent duration in patients with ICH intracranial hemorrhage associated with warfarin use.

Recombinant activated factor VII for a warfarinised Jehovah’s Witness with an acute subdural haematoma

Recombinant activated factor VII (rFVIIa) (NovoSeven; Novo Nordisk A/S, Bagsvaerd, Denmark) is a haemostatic agent first developed for bleeding associated with haemophilia and trauma, but for which the indications continue to expand. Recent reports have suggested efficacy for various types of intracranial haemorrhage and for patients with abnormalities of coagulation. We report a warfarin-anticoagulated Jehovah's Witness patient with an acute subdural haematoma for whom rFVIIa was used perioperatively. The haematoma was surgically evacuated without excessive blood loss and the patient eventually made a good recovery, returning to independent self-care.

Polyphosphate as a general procoagulant agent

BACKGROUND

Polyphosphate is secreted by activated platelets and we recently showed that it accelerates blood clotting, chiefly by triggering the contact pathway and promoting factor (F) V activation.

RESULTS

We now report that polyphosphate significantly shortened the clotting time of plasmas from patients with hemophilia A and B and that its procoagulant effect was additive to that of recombinant FVIIa. Polyphosphate also significantly shortened the clotting time of normal plasmas containing a variety of anticoagulant drugs, including unfractionated heparin, enoxaparin (a low molecular weight heparin), argatroban (a direct thrombin inhibitor) and rivaroxaban (a direct FXa inhibitor). Thromboelastography revealed that polyphosphate normalized the clotting dynamics of whole blood containing these anticoagulants, as indicated by changes in clot time, clot formation time, alpha angle, and maximum clot firmness. Experiments in which preformed FVa was added to plasma support the notion that polyphosphate antagonizes the anticoagulant effect of these drugs via accelerating FV activation. Polyphosphate also shortened the clotting times of plasmas from warfarin patients.

CONCLUSION

These results suggest that polyphosphate may have utility in reversing anticoagulation and in treating bleeding episodes in patients with hemophilia.

Low-dose recombinant factor VIIa for trauma patients with coagulopathy

INTRODUCTION

Coagulopathy in injured patients is common and is generally treated with fresh frozen plasma (FFP). Response can be variable, thus complete correction may take hours and require large volumes of fluids. High-dose recombinant factor VIIa (FVIIa, Novoseven, Novo Nordisk, Bagsvaerd, Denmark) has been used off-label to treat severe coagulopathy following trauma. Expense has limited use. Recently, we began administering low dose FVIIa (1.2mg) to patients with mild to moderate coagulopathy after trauma, hypothetising that it would be effective and safe.

PATIENTS AND METHODS

We retrospectively reviewed consecutive patients who received a low dose of 1.2mg of FVIIa over a 2-year period. Factor VIIa is administered after approval by a gatekeeper at the discretion of the treating physician. Demographics, injury and laboratory data were abstracted as were indications for use, source of coagulopathy, effectiveness, and complications. A two-tailed paired t-test was used to determine significant changes in coagulation parameters and blood product utilisation.

RESULTS

Eighty-one patients received 84 low doses of FVIIa. The mean age of the patients was 51 (+/-22) with a mean ISS of 29 (+/-11). Seventy-three per cent were male and 67% had a traumatic brain injury (TBI) as their primary injury. The aetiology of the coagulopathy in the study population included; TBI (40%), warfarin use (22%), and cirrhosis (13%). Mean prothrombin time (PT) fell from 17.0 s (+/-3.2) to 10.6s (+/-1.4) (p<0.0001). All patients had a good clinical response with no bleeding complications. Utilisation of packed red blood cells and fresh frozen plasma were significantly less in the 24h after FVIIa administration as compared to the 24h prior. Subsequent thromboembolic events were observed in 12 of the 81 patients (15%) and included; cerebrovascular accident (CVA) (6), mesenteric thrombosis (2), myocardial infarction (MI) (1), pulmonary embolism/deep venous thrombosis (PE/DVT) (2), and atrial thrombus (1). Only four of these events were thought to be related to the FVIIa administration, with two of the four contributing to a lethal outcome.

CONCLUSIONS

Low dose FVIIa rapidly and effectively treats mild to moderate coagulopathy following injury. This low dose (1.2mg) FVIIa is the smallest available unit dose. It costs approximately the same as 8 units of plasma and may be cost-effective in patients who require high volume factor administration. Low dose FVIIa may be effective in coagulopathic trauma patients who are not in shock but require rapid normalisation of clotting function.