Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms

Advances in the medical treatment and diagnosis of intracranial hemorrhage associated with oral anticoagulation

INTRODUCTION

With the increasing prevalence of atrial fibrillation (AF), it entails expanding oral anticoagulants (OACs) use, carrying a higher risk of associated hemorrhagic events, including intracranial hemorrhage (ICH). Despite advances in OACs development with a better safety profile and reversal agent for these anticoagulants, there is still no consensus on the optimal management of patients with OACs-associated ICH.

AREAS COVERED

In this review, the authors have carried out an exhaustive search on the advances in recent years. The authors provide an update on the management of ICH in anticoagulated patients, as well as an update on the latest evidence on anticoagulation resumption, recent therapeutic strategies, and investigational drugs that could play a role in the future.

EXPERT OPINION

Following an ICH event in an anticoagulated patient, a comprehensive clinical evaluation is imperative. Anticoagulation should be promptly withdrawn and reversed. Once the patient is stabilized, a reintroduction of anticoagulation should be considered, typically within a timeframe of 4-8 weeks, if feasible. If re-anticoagulation is not possible, alternative options such as Left Atrial Appendage Occlusion are available.

Vitamin K: a potential missing link in critical illness-a scoping review

BACKGROUND

Vitamin K is essential for numerous physiological processes, including coagulation, bone metabolism, tissue calcification, and antioxidant activity. Deficiency, prevalent in critically ill ICU patients, impacts coagulation and increases the risk of bleeding and other complications. This review aims to elucidate the metabolism of vitamin K in the context of critical illness and identify a potential therapeutic approach.

METHODS

In December 2023, a scoping review was conducted using the PRISMA Extension for Scoping Reviews. Literature was searched in PubMed, Embase, and Cochrane databases without restrictions. Inclusion criteria were studies on adult ICU patients discussing vitamin K deficiency and/or supplementation.

RESULTS

A total of 1712 articles were screened, and 13 met the inclusion criteria. Vitamin K deficiency in ICU patients is linked to malnutrition, impaired absorption, antibiotic use, increased turnover, and genetic factors. Observational studies show higher PIVKA-II levels in ICU patients, indicating reduced vitamin K status. Risk factors include inadequate intake, disrupted absorption, and increased physiological demands. Supplementation studies suggest vitamin K can improve status but not normalize it completely. Vitamin K deficiency may correlate with prolonged ICU stays, mechanical ventilation, and increased mortality. Factors such as genetic polymorphisms and disrupted microbiomes also contribute to deficiency, underscoring the need for individualized nutritional strategies and further research on optimal supplementation dosages and administration routes.

CONCLUSIONS

Addressing vitamin K deficiency in ICU patients is crucial for mitigating risks associated with critical illness, yet optimal management strategies require further investigation.

IMPACT RESEARCH

To the best of our knowledge, this review is the first to address the prevalence and progression of vitamin K deficiency in critically ill patients. It guides clinicians in diagnosing and managing vitamin K deficiency in intensive care and suggests practical strategies for supplementing vitamin K in critically ill patients. This review provides a comprehensive overview of the existing literature, and serves as a valuable resource for clinicians, researchers, and policymakers in critical care medicine.

Anticoagulation and Antiplatelet Agent Resumption Timing following Traumatic Brain Injury

Traumatic brain injury (TBI) is a major global health concern. Due to the increase in TBI incidence and the aging population, an increasing number of patients with TBI are taking antithrombotic agents for their underlying disease. When TBI occurs in patients with these diseases, there is a conflict between the disease, which requires an antithrombotic effect, and the neurosurgeon, who must minimize intracranial hemorrhage. Nevertheless, there are no clear guidelines for the reversal or resumption of antithrombotic agents when TBI occurs in patients taking antithrombotic agents. In this review article, we intend to classify antithrombotic agents and provide information on them. We also share previous studies on the reversal and resumption of antithrombotic agents in patients with TBI to help neurosurgeons in this dilemma.

The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition

BACKGROUND

Severe trauma represents a major global public health burden and the management of post-traumatic bleeding continues to challenge healthcare systems around the world. Post-traumatic bleeding and associated traumatic coagulopathy remain leading causes of potentially preventable multiorgan failure and death if not diagnosed and managed in an appropriate and timely manner. This sixth edition of the European guideline on the management of major bleeding and coagulopathy following traumatic injury aims to advise clinicians who care for the bleeding trauma patient during the initial diagnostic and therapeutic phases of patient management.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma included representatives from six European professional societies and convened to assess and update the previous version of this guideline using a structured, evidence-based consensus approach. Structured literature searches covered the period since the last edition of the guideline, but considered evidence cited previously. The format of this edition has been adjusted to reflect the trend towards concise guideline documents that cite only the highest-quality studies and most relevant literature rather than attempting to provide a comprehensive literature review to accompany each recommendation.

RESULTS

This guideline comprises 39 clinical practice recommendations that follow an approximate temporal path for management of the bleeding trauma patient, with recommendations grouped behind key decision points. While approximately one-third of patients who have experienced severe trauma arrive in hospital in a coagulopathic state, a systematic diagnostic and therapeutic approach has been shown to reduce the number of preventable deaths attributable to traumatic injury.

CONCLUSION

A multidisciplinary approach and adherence to evidence-based guidelines are pillars of best practice in the management of severely injured trauma patients. Further improvement in outcomes will be achieved by optimising and standardising trauma care in line with the available evidence across Europe and beyond.

Application of fresh frozen plasma transfusion in the management of excessive warfarin-associated anticoagulation

Warfarin is a commonly used oral anticoagulant. Patients with artificial valve replacement, atrial fibrillation, pulmonary embolism, deep vein thrombosis, and other diseases require long-term anticoagulant oral treatment with warfarin. As warfarin exhibits prompt action with long maintenance time, it has become a key drug for the treatment of patients at risk of developing thrombosis or thromboembolism. Warfarin is a bican coumarin anticoagulant, that exhibits competitive action against vitamin K as its mechanism of action, thereby inhibiting the synthesis of coagulation factors—predominantly the vitamin K-dependent coagulation factors II, VII, IX, and X—in hepatocytes. Long-term warfarin is known to significantly increase the risk of organ bleeding in some patients, while some patients may need to reverse the anticoagulation effect. For instance, patients scheduled for emergency or invasive surgery may require rapid anticoagulation reversal. During such medical circumstances, fresh frozen plasma (FFP) is clinically used for the reversal of excess warfarin-associated anticoagulation, as it contains all the coagulation factors that can alleviate the abnormal blood anticoagulation status in such patients. Accordingly, this article aims to perform an in-depth review of relevant literature on the reversal of warfarin with FFP, and insightful deliberation of the application and efficacy of this clinical intervention.

Perioperative management of antithrombotic therapy: a case-based narrative review

The periprocedural management of patients who are receiving vitamin K antagonists, direct oral anticoagulants and antiplatelet therapy is a common and challenging clinical scenario as the decision to interrupt or continue these medications is anchored on patient and procedure-related risks for bleeding and thrombosis. Adding to the complexity of clinical management is the fact that anticoagulants have varied pharmacokinetic and pharmacodynamic properties and indications for clinical use. In many minimal-bleed-risk procedures, anticoagulants can be safely continued, without interruption, whereas in cases where anticoagulants cannot be safely continued, the timing of interruption and resumption, as well as the need for heparin bridging requires consideration. Perioperative antithrombotic management scenarios occur most often in patients with atrial fibrillation, mechanical heart valves, coronary stents, and cerebrovascular disease as such patients are likely to be prescribed anticoagulant and/or antiplatelet therapy. The objective of this case-based narrative review is to provide a practical evidence-based approach to the perioperative management of patients on anticoagulation and antiplatelet therapy. Four clinical scenarios will be provided: (1) managing patients in whom anticoagulants can be continued; (2) perioperative management of direct oral anticoagulants; (3) management of patients on dual antiplatelet therapy; and (4) anticoagulant management for emergency or urgent surgery.

Vitamin K for reversal of excessive vitamin K antagonist anticoagulation: a systematic review and meta-analysis

Patients receiving vitamin K antagonists (VKAs) with an international normalized ratio (INR) between 4.5 and 10 are at increased risk of bleeding. We systematically reviewed the literature to evaluate the effectiveness and safety of administering vitamin K in patients receiving VKA therapy with INR between 4.5 and 10 and without bleeding. Medline, Embase, and Cochrane databases were searched for relevant randomized controlled trials in April 2018. Search strategy included terms vitamin K administration and VKA-related terms. Reference lists of relevant studies were reviewed, and experts in the field were contacted for relevant papers. Two investigators independently screened and collected data. Risk ratios (RRs) were calculated, and certainty of the evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation. Six studies (1074 participants) were included in the review and meta-analyses. Pooled estimates indicate a nonsignificant increased risk of mortality (RR = 1.42; 95% confidence interval [CI], 0.62-2.47), bleeding (RR = 2.24; 95% CI, 0.81-7.27), and thromboembolism (RR = 1.29; 95% CI, 0.35-4.78) for vitamin K administration, with moderate certainty of the evidence resulting from serious imprecision as CIs included potential for benefit and harm. Patients receiving vitamin K had a nonsignificant increase in the likelihood of reaching goal INR (1.95; 95% CI, 0.88-4.33), with very low certainty of the evidence resulting from serious risk of bias, inconsistency, and imprecision. Our findings indicate that patients on VKA therapy who have an INR between 4.5 and 10.0 without bleeding are not likely to benefit from vitamin K administration in addition to temporary VKA cessation.

Preoperative Vitamin K Reduces Blood Transfusions at Time of Left Ventricular Assist Device Implant

BACKGROUND

Congestive heart failure patients have hepatic congestion and abnormal coagulation profiles, increasing perioperative bleeding at time of ventricular assist device implantation. This study examined the impact of the preoperative administration of vitamin K on perioperative blood transfusion requirements.

METHODS

Retrospectively, 190 patients met inclusion criteria. Patients received no vitamin K (n = 62) or two 10-mg doses of intravenous vitamin K (n = 128) in the 24 hours before assist device implantation. Primary end points included transfusion requirements and reexploration rates for bleeding. Secondary outcomes were pump thrombosis and in-hospital mortality.

RESULTS

Baseline characteristics were similar between the 2 groups, with slight differences (not statistically significant) noted in the Interagency Registry for Mechanically Assisted Circulatory Support profile and total bilirubin levels. The only significant difference noted was the year of implantation (P < .001). Blood product usage was significantly lower in the vitamin K group compared to the no vitamin K group (P < .001). Higher rates of reexploration for bleeding (29.7% vs 13.6%, P = .023) and death at hospital discharge (16.2% vs 2.8%, P = .004) were noted for the no vitamin K group compared with the vitamin K group. After adjusting for age, sex, race, body mass index, Interagency Registry for Mechanically Assisted Circulatory Support profile, total bilirubin, surgeon, and year of operation, reexploration rates and death did not achieve statistical significance. No statistically significant difference was observed in stroke and pump thrombosis rates between the 2 groups.

CONCLUSIONS

Preoperative vitamin K administration may help reduce blood product use without any increased risk for strokes or pump thrombosis.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.

Anticoagulation for venous thromboembolism

Acute venous thromboembolism (VTE) is treated with parenteral administration of heparin or derivatives, in conjunction with oral vitamin K antagonists (VKAs) to reach and maintain INR values between 2.0 and 3.0 for at least 3 months; the duration of a further period of treatment for secondary prevention of recurrences is still matter of debate. If bleeding occurs during treatment the decision will be based on: a) type of bleeding (major or minor), and b) thrombotic risk if anticoagulation is withheld (characteristics of patients and time elapsed from the index VTE). In case of major bleeding anticoagulation should be stopped and reversed. A first but insufficient measure is i.v. vitamin K administration. Fresh frozen plasma is widely used; however, large volumes are needed (at least 15 mL/kg body weight) with risk for fluid overload. Prothrombin complex concentrate infusion, with 3 or (better) the 4 pro-coagulant factors, is a more efficient (fast and safe) measure. In patients at high thrombotic risk (first month or other conditions) and absolute contraindication for anticoagulation a caval filter is recommended, to avoid as much as possible lifethreatening pulmonary embolism.

Anticoagulants

Anticoagulants are effective in the prevention and treatment of a variety of arterial and venous thrombotic disorders but are associated with an increased risk of serious bleeding complications. Based on well documented studies of patients using vitamin K antagonists the incidence of major bleeding is 0.5%/year and the incidence of intracranial bleeding is 0.2%/year, however, in real life practice this incidence may be even higher. Risk factors for bleeding are the intensity of anticoagulation, the management strategy to keep the anticoagulant effect in the desired range, and patient characteristics. Recently, a new generation of anticoagulants have been developed and is currently evaluated in clinical trials. Initial results show a similar or superior efficacy over conventional anticoagulant agents with a good safety profile. In case of serious bleeding complications in a patient who uses vitamin K antagonists, this anticoagulant treatment can be quickly reversed by administration of vitamin K or coagulation factor concentrates. For the newer anticoagulants, quick reversal strategies are more cumbersome, although some interventions, including prothrombin complex concentrates, show promising results in initial experimental studies.

Bleeding risk assessment and management in atrial fibrillation patients

In this executive summary of a Consensus Document from the European Heart Rhythm Association, endorsed by the European Society of Cardiology Working Group on Thrombosis, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in atrial fibrillation (AF) patients. The main aim of the document was to summarise ‘best practice’ in dealing with bleeding risk in AF patients when approaching antithrombotic therapy, by addressing the epidemiology and size of the problem, and review established bleeding risk factors. We also summarise definitions of bleeding in the published literature. Patient values and preferences balancing the risk of bleeding against thromboembolism as well as the prognostic implications of bleeding are reviewed. We also provide an overview of published bleeding risk stratification and bleeding risk schema. Brief discussion of special situations (e.g. periablation, peri-devices such as implantable cardioverter defibrillators [ICD] or pacemakers, presentation with acute coronary syndromes and/or requiring percutanous coronary interventions/stents and bridging therapy) is made, as well as a discussion of the prevention of bleeds and managing bleeding complications. Finally, this document puts forwards consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Point-of-care testing in the acute management of traumatic brain injury: Identifying the coagulopathic patient

Background:

The use of anticoagulants or antiplatelet medications has become increasingly common and is a well-established risk factor for worsening of hemorrhages in trauma patients. The current study addresses the need to investigate the efficacy of point-of-care tests (POC) as an adjunct to conventional coagulation testing in traumatic brain injury (TBI) patients.

Methods:

A retrospective review of 190 TBI patients >18 years of age who underwent both conventional and POC testing as part of their admission coagulopathy workup was conducted. Coagulation deficiency was defined as an international normalized ratio (INR) >1.4, a reaction time (r-value) on rapid thromboelastography >50 seconds, or a VerifyNow Aspirin (VN-ASA) level of < 550 Aspirin Reaction Units.

Results:

Among 190 patients, 91 (48%) disclosed a history of either warfarin or antiplatelet use or had documented INR >1.4. Of the 18 (9%) patients who reported warfarin use, 83% had elevated INR and 61% had elevated r-value. However, 41% of the patients without reported anticoagulant usage revealed significantly elevated r-value consistent with a post-traumatic hypocoagulable state. Of 64 (34%) patients who reported taking ASA, 51 (80%) demonstrated therapeutic VN-ASA. Interestingly, 31 of 126 (25%) patients not reporting ASA use were also noted to have therapeutic VN-ASA suggestive of platelet dysfunction.

Conclusions:

The coagulopathy POC panel consisting of r-TEG and VN-ASA successfully identified a subset of TBI patients with an occult coagulopathy that would have otherwise been missed. Standardization of these POC assays on admission in TBI may help guide patient resuscitation in the acute setting.

Management of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a potentially devastating neurologic injury representing 10-15% of stroke cases in the USA each year. Numerous risk factors, including age, hypertension, male gender, coagulopathy, genetic susceptibility, and ethnic descent, have been identified. Timely identification, workup, and management of this condition remain a challenge for clinicians as numerous factors can present obstacles to achieving good functional outcomes. Several large clinical trials have been conducted over the prior decade regarding medical and surgical interventions. However, no specific treatment has shown a major impact on clinical outcome. Current management guidelines do exist based on medical evidence and consensus and these provide a framework for care. While management of hypertension and coagulopathy are generally considered basic tenets of ICH management, a variety of measures for surgical hematoma evacuation, intracranial pressure control, and intraventricular hemorrhage can be further pursued in the emergent setting for selected patients. The complexity of management in parenchymal cerebral hemorrhage remains challenging and offers many areas for further investigation. A systematic approach to the background, pathology, and early management of spontaneous parenchymal hemorrhage is provided.

Budget impact analysis of warfarin reversal therapies among hip fracture patients in Finland

BACKGROUND

Hip fractures require operation within 36-48 h, and they are most common in the elderly. A high International Normalized Ratio should be corrected before surgery. In the current study, we analyzed the budget impact of various warfarin reversal approaches.

METHODS

Four reversal strategies were chosen for the budget impact analysis: the temporary withholding of warfarin, administration of vitamin K, fresh frozen plasma (FFP), and a four-factor prothrombin complex concentrate (PCC).

RESULTS

We estimated that, annually, 410 hip fracture patients potentially require warfarin reversal in Finland. The least costly treatment was vitamin K, which accounted for €289,000 in direct healthcare costs, and the most costly treatment option was warfarin cessation, which accounted for €1,157,000. In the budget impact analysis, vitamin K, PCC and FFP would be cost-saving to healthcare compared with the current treatment mix.

CONCLUSION

The various warfarin reversal strategies have different onset times, which may substantially impact the subsequent healthcare costs.

[Disorders of hemostasis in surgical intensive care at the University Hospital Joseph Ravoahangy Andrianavalona Antananarivo]

Les troubles de l'hémostase sont fréquemment observés en réanimation. L'objectif de cette étude est d'en déterminer l'incidence, les étiologies et la prise en charge pour en diminuer le risque de morbi-mortalité. Etude rétrospective sur une période de huit mois en réanimation chirurgicale du CHUA HUJRA. Les dossiers étudiés étaient ceux contenant tous les premiers bilans d'hémostase lors de l'admission du patient en réanimation, avec un âge supérieur à 15 ans. Etaient exclus les dossiers des post opérés (malade ayant subi une intervention chirurgicale). Les dossiers retenus pour l'étude étaient ceux qui ont présenté une ou plusieurs anomalies au niveau du bilan d'hémostase. Cent cinquante-cinq dossiers ont été colligés dont 20,64% ont présenté un trouble de l'hémostase. Les patients de sexe féminin (53,12%) étaient les plus concernés, avec une population âgée en moyenne de 49±19 ans. Trois patients (9,37%) ont présenté une notion de diathèse hémorragique à l'interrogatoire. Les différents troubles de l'hémostase étaient: une diminution du taux de prothrombine (100%), un taux de céphaline activé allongé (78,12%), un international normalized ratio élevé (43,75%) et des thrombopénies (40,62%). Chez 3,12% de ces cas, des accidents hémorragiques ont survenu. La plupart de ces troubles de l'hémostase étaient présents au décours d'hémorragies digestives (46,87%) dont la prise en charge était constituée par l'administration de vitamine K1 (68,75%) et de transfusion de plasma frais congelé (65,62%). D'autres pathologies ont été également incriminées. Une incidence de 15,62% de mortalité a été retrouvée. L'existence des troubles de l'hémostase en réanimation constitue un facteur pronostique imposant un dépistage et une prise en charge précoces et adéquats pour pouvoir en réduire le taux de mortalité.

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.

Is bleeding a necessary evil? The inherent risk of antithrombotic pharmacotherapy used for stroke prevention in atrial fibrillation

Current European atrial fibrillation (AF) guidelines have assigned a strong recommendation for the initiation of antithrombotic therapy to prevent thromboembolism in all but those AF patients at low risk (or with contraindications). Furthermore, the selection of antithrombotic therapy is based on the absolute risks of thromboembolism and bleeding, and the relative risk and benefit for a given patient. By their very mechanism of action, antithrombotic agents used for stroke prevention in AF will potentially increase the risk of bleeding events. Moreover, the introduction of novel oral anticoagulation agents have introduced new, hitherto ill-defined, deficiencies in the authors' knowledge with respect to anticoagulation monitoring, availability of direct antidotes, drug-drug interactions and the ability to appropriately control and reverse their actions if bleeding events occur. The authors present a comprehensive review on all aspects of bleeding related to currently licensed antithrombotic agents used for stroke prevention in patients with AF.

Management of major bleeding events in patients treated with rivaroxaban vs. warfarin: results from the ROCKET AF trial

AIMS

There are no data regarding management and outcomes of major bleeding events in patients treated with oral factor Xa inhibitors.

METHODS AND RESULTS

Using data from ROCKET AF, we analysed the management and outcomes of major bleeding overall and according to the randomized treatment. During a median follow-up of 1.9 years, 779 (5.5%) patients experienced major bleeding at a rate of 3.52 events/100 patient-years with a similar event rate in each arm (n = 395 rivaroxaban vs. n = 384 warfarin). The median number of transfused packed red blood cells (PRBC) per episode was similar in both arms [2 (25th, 75th: 2, 4) units]. Overall, few transfusions of whole blood (n = 14), platelets (n = 10), or cryoprecipitate (n = 2) were used. Transfusion of fresh frozen plasma (FFP) was significantly less in the rivaroxaban arm (n = 45 vs. n = 81 units) after adjustment for covariates [odds ratio (OR) 0.43 (95% CI 0.29-0.66); P < 0.0001]. Prothrombin complex concentrates (PCC) were administered less in the rivaroxaban arm (n = 4 vs. n = 9). Outcomes after major bleeding, including stroke or non-central nervous system embolism (4.7% rivaroxaban vs. 5.4% warfarin; HR 0.89; 95% CI 0.42-1.88) and all-cause death (20.4% rivaroxaban vs. 26.1% warfarin; HR 0.69, 95% CI 0.46-1.04) were similar in patients treated with rivaroxaban and warfarin (interaction P = 0.51 and 0.11).

CONCLUSION

Among high-risk patients with atrial fibrillation who experienced major bleeding in ROCKET AF, the use of FFP and PCC was less among those allocated rivaroxaban compared with warfarin. However, use of PRBCs and outcomes after bleeding were similar among patients randomized to rivaroxaban or to warfarin.

Outcomes of urgent warfarin reversal with frozen plasma versus prothrombin complex concentrate in the emergency department

BACKGROUND

Physicians reverse patients' warfarin anticoagulation with frozen plasma or prothrombin complex concentrate. Our objective was to determine adverse event frequency after urgent reversal with frozen plasma versus the prothrombin complex concentrate Octaplex.

METHODS AND RESULTS

This natural before-after retrospective cohort study in 2 tertiary care emergency departments compared anticoagulation reversal with frozen plasma (September 2006-August 2008) and with Octaplex (September 2008-August 2010), without other system changes. We included adult patients on warfarin with an international normalized ratio ≥1.5 who received frozen plasma or Octaplex. Our primary outcome was serious adverse events (death, ischemic stroke, myocardial infarction, heart failure, venous thromboembolism, or peripheral arterial thromboembolism) within 7 days. Secondary outcomes included time to international normalized ratio reversal, hospital length of stay, and red blood cells transfused within 48 hours. We included 149 patients receiving frozen plasma and 165 receiving Octaplex. The incidence of serious adverse events for the frozen plasma group was 19.5% compared with 9.7% for the Octaplex group (P=0.014; relative risk, 2.0; 95% confidence interval, 1.1-3.5). This remained significant after adjustment for baseline history and reason for treatment (P=0.038; adjusted relative risk, 1.85; 95% confidence interval, 1.03-3.3) in multivariable regression analysis. Median international normalized ratio reversal was 11.8 hours with frozen plasma and 5.7 hours with Octaplex (P<0.0001). Mean red cell transfusion was 3.2 with frozen plasma and 1.4 with Octaplex (P<0.0001).

CONCLUSIONS

Octaplex for urgent reversal of warfarin resulted in faster reversal and lower red cell transfusion requirement with fewer adverse events than frozen plasma.

Pharmacologic reversal of warfarin-associated coagulopathy in geriatric patients with hip fractures: a retrospective study of thromboembolic events, postoperative complications, and time to surgery

PURPOSE

Patients with acute hip fractures who are on maintenance warfarin for anticoagulation present a significant challenge and their management remains controversial. The purpose of this study was to assess thromboembolic and systemic complications associated with pharmacological reversal of warfarin-associated coagulopathy in a population of geriatric patients with hip fractures.

METHODS

This retrospective cohort study identified patients with operative hip fractures on oral warfarin therapy who had an international normalized ratio (INR) >1.50 on admission (N = 93) approximately over a 13-year span. The control group consisted of patients whose warfarin was held upon admission without further intervention preoperatively (n = 23). The treatment group consisted of patients who underwent pharmacologic reversal of elevated INR with vitamin K and/or fresh frozen plasma (FFP) in addition to holding warfarin (n = 70). Primary outcomes included thromboembolic and other complications as well as mortality within 3 months of presentation. Time to surgery was a secondary outcome.

RESULTS

The 3-month mortality rate was 4% in the pharmacological intervention group and 17% in the watch-and-wait group; this difference trended toward statistical significance (P = .06). There were no significant differences in the likelihoods of other thromboembolic or nonthromboembolic complications between groups. While the difference in mean time to surgery was not significantly different overall between groups, this difference was significant in a subgroup of patients with higher baseline INRs (n = 46, INR >2.17), with a mean difference of 4.0 fewer days until surgery in the pharmacological intervention group (P < .01).

CONCLUSIONS

Pharmacological reversal of warfarin-associated coagulopathy with a combination of vitamin K and FFP appears to be a safe way to optimize patients for operative fixation of hip fractures and is associated with a shorter delay to surgery in patients with more elevated INRs preoperatively.

LEVEL OF EVIDENCE

retrospective cohort study (level III).

Optimizing drug therapy in the surgical intensive care unit

This article provides a review of commonly prescribed medications in the surgical ICU, focusing on sedatives, antipsychotics, neuromuscular blocking agents, cardiovascular agents, anticoagulants, and antibiotics. A brief overview of pharmacology is followed by practical considerations to aid prescribers in selecting the best therapy within a given category of drugs to optimize patient outcomes.

A French multicenter randomised trial comparing two dose-regimens of prothrombin complex concentrates in urgent anticoagulation reversal

INTRODUCTION

Prothrombin complex concentrates (PCC) are haemostatic blood preparations indicated for urgent anticoagulation reversal, though the optimal dose for effective reversal is still under debate. The latest generation of PCCs include four coagulation factors, the so-called 4-factor PCC. The aim of this study was to compare the efficacy and safety of two doses, 25 and 40 IU/kg, of 4-factor PCC in vitamin K antagonist (VKA) associated intracranial haemorrhage.

METHODS

We performed a phase III, prospective, randomised, open-label study including patients with objectively diagnosed VKA-associated intracranial haemorrhage between November 2008 and April 2011 in 22 centres in France. Patients were randomised to receive 25 or 40 IU/kg of 4-factor PCC. The primary endpoint was the international normalised ratio (INR) 10 minutes after the end of 4-factor PCC infusion. Secondary endpoints were changes in coagulation factors, global clinical outcomes and incidence of adverse events (AEs).

RESULTS

A total of 59 patients were randomised: 29 in the 25 IU/kg and 30 in the 40 IU/kg group. Baseline demographics and clinical characteristics were comparable between the groups. The mean INR was significantly reduced to 1.2 - and ≤1.5 in all patients of both groups - 10 minutes after 4-factor PCC infusion. The INR in the 40 IU/kg group was significantly lower than in the 25 IU/kg group 10 minutes (P = 0.001), 1 hour (P = 0.001) and 3 hours (P = 0.02) after infusion. The 40 IU/kg dose was also effective in replacing coagulation factors such as PT (P = 0.038), FII (P = 0.001), FX (P <0.001), protein C (P = 0.002) and protein S (0.043), 10 minutes after infusion. However, no differences were found in haematoma volume or global clinical outcomes between the groups. Incidence of death and thrombotic events was similar between the groups.

CONCLUSIONS

Rapid infusion of both doses of 4-factor PCC achieved an INR of 1.5 or less in all patients with a lower INR observed in the 40 IU/kg group. No safety concerns were raised by the 40 IU/kg dose. Further trials are needed to evaluate the impact of the high dose of 4-factor PCC on functional outcomes and mortality.

TRIAL REGISTRATION

Eudra CT number 2007-000602-73.

Vitamin K dosing to reverse warfarin based on INR, route of administration, and home warfarin dose in the acute/critical care setting

BACKGROUND

Vitamin K is commonly used for reversal of anticoagulation of warfarin. However, the optimal dose and route of vitamin K that does not increase the duration of bridging therapy is unknown.

OBJECTIVE

To determine factors influencing the extent and rate of INR reversal with vitamin K in the acute/critical care setting.

METHODS

This was a chart review of 400 patients who received vitamin K for reversal of warfarin effects between February 2008 and November 2010. Data collected included international normalized ratios (INRs) 12 hours, 24 hours, and 48 hours prior to vitamin K administration; intravenous or oral vitamin K dose; and whether or not fresh frozen plasma (FFP) was administered.

RESULTS

Intravenous vitamin K reduced INR more rapidly than oral vitamin K (5.09, 1.91, 1.54, and 1.41 vs 5.67, 2.90, 2.14, and 1.58) at baseline, 12, 24, and 48 hours, respectively. The dose of vitamin K (p < 0.001), route of administration (p < 0.001), and baseline INR (p < 0.001) influenced subsequent INR values. The INR reduction was similar for intravenous vitamin K doses 2 mg or greater. Home warfarin dose did not affect INR responses to intravenous (p = 0.27) or oral vitamin K (p = 0.98). FFP did not influence INR values at 48 hours. Although longer anticoagulation bridge therapy seemed to be associated with higher vitamin K doses, the incidence (p = 0.63) and duration (p = 0.61) were not significant.

CONCLUSIONS

Vitamin K dose, route, and initial INR influence subsequent INR values. INR reduction is similar for intravenous vitamin K doses of 2 mg or greater. Preadministration of FFP does not alter INR values at 48 hours or more after vitamin K administration.

Reversal of Vitamin K Antagonist (VKA) effect in patients with severe bleeding: a French multicenter observational study (Optiplex) assessing the use of Prothrombin Complex Concentrate (PCC) in current clinical practice

Introduction

Prothrombin Complex Concentrate (PCC) is a key treatment in the management of bleeding related to Vitamin K antagonists (VKA). This study aimed to evaluate prospectively PCC use in patients with VKA-related bleeding in view of the French guidelines published in 2008.

Methods

All consecutive patients with VKA-related bleeding treated with a 4-factor PCC (Octaplex^®) were selected in 33 French hospitals. Collected data included demographics, site and severity of bleeding, modalities of PCC administration, International Normalized Ratio (INR) values before and after PCC administration, outcomes and survival rate 15 days after infusion.

Results

Of 825 patients who received PCC between August 2008 and December 2010, 646 had severe bleeding. The main haemorrhage sites were intracranial (43.7%) and abdominal (24.3%). Mean INR before PCC was 4.4 ± 1.9; INR was unavailable in 12.5% of patients. The proportions of patients who received a PCC dose according to guidelines were 15.8% in patients with initial INR 2-2.5, 41.5% in patients with INR 2.5-3, 40.8% in patients with INR 3-3.5, 26.9% in patients with INR > 3.5, and 63.5% of patients with unknown INR. Vitamin K was administered in 84.7% of patients. The infused dose of PCC did not vary with initial INR; the mean dose was 25.3 ± 9.8 IU/Kg. Rates of controlled bleeding and target INR achievement were similar, regardless of whether or not patients were receiving PCC doses as per the guidelines. No differences in INR after PCC treatment were observed, regardless of whether or not vitamin K was administered. INR was first monitored after a mean time frame of 4.5 ± 5.6 hours post PCC. The overall survival rate at 15 days after PCC infusion was 75.4% (65.1% in patients with intracranial haemorrhage). A better prognosis was observed in patients reaching the target INR.

Conclusions

Severe bleeding related to VKA needs to be better managed, particularly regarding the PCC infused dose, INR monitoring and administration of vitamin K. A dose of 25 IU/kg PCC appears to be efficacious in achieving a target INR of 1.5. Further studies are required to assess whether adjusting PCC dose and/or better management of INR would improve outcomes.

Reversal of warfarin-induced hemorrhage in the emergency department

Warfarin, an oral vitamin K antagonist, is used to prevent arterial and venous thromboembolism in patients suffering from a multitude of diseases. In 2004, 31 million warfarin prescriptions were dispensed in the United States. Warfarin inhibits the activation of the vitamin K-dependent clotting factors (Factors II, VII, IX, and X) and regulatory proteins (proteins C, S, and Z). It is one of the leading drugs implicated in emergency room visits for adverse drug reactions. Annually the frequency of bleeding complications associated with overanticoagulation is 15% to 20%, with fatal bleeds measuring as high as 1% to 3%. The most effective method of warfarin reversal involves the use of Four Factor Prothrombin Complex Concentrate (PCC), which is widely used throughout Europe but is unavailable in the United States. The current therapies available to emergency room physicians in the United States are fresh frozen plasma, recombinant Factor VIIa (rFVIIa), Factor Eight Inhibitory Bypassing Activity, or Three Factor PCC concomitantly administered with vitamin K. We review the advantages and disadvantages of these therapies and recommend Three Factor PCC with small doses of rFVIIa and with vitamin K in life-threatening situations if Four Factor PCC is unavailable.

Management dilemmas in patients with mechanical heart valves and warfarin-induced major bleeding

Management of warfarin-induced major bleeding in patients with mechanical heart valves is challenging. There is vast controversy and confusion in the type of treatment required to reverse anticoagulation and stop bleeding as well as the ideal time to restart warfarin therapy safely without recurrence of bleeding and/or thromboembolism. Presently, the treatments available to reverse warfarin-induced bleeding are vitamin K, fresh frozen plasma, prothrombin complex concentrates and recombinant activated factor VIIa. Currently, vitamin K and fresh frozen plasma are the recommended treatments in patients with mechanical heart valves and warfarin-induced major bleeding. The safe use of prothrombin complex concentrates and recombinant activated factor VIIa in patients with mechanical heart valves is controversial and needs well-designed clinical studies. With regard to restarting anticoagulation in patients with warfarin-induced major bleeding and mechanical heart valves, the safe period varies from 7-14 d after the onset of bleeding for patients with intracranial bleed and 48-72 h for patients with extra-cranial bleed. In this review article, we present relevant literature about these controversies and suggest recommendations for management of patients with warfarin-induced bleeding and a mechanical heart valve. Furthermore, there is an urgent need for separate specific guidelines from major associations/ professional societies with regard to mechanical heart valves and warfarin-induced bleeding.

Treatment of warfarin-associated coagulopathy with vitamin K

Warfarin is the most common form of oral anticoagulant therapy. Although it has indisputable benefit in the management of thromboembolic disease, warfarin-associated coagulopathy (WAC) is a well-documented complication of its use. As warfarin exerts its effect by impairing formation of the vitamin K-dependent clotting factors, a cornerstone of WAC management is vitamin K replacement. Daily vitamin K supplementation is an emerging approach to regulate international normalized ratios in difficult-to-control patients. Mild WAC without bleeding can often be managed with warfarin withdrawal alone. For excessive international normalized ratio elevation in the absence of bleeding, low-dose oral vitamin K (1?2.5 mg) is sufficient and achieves the same degree of international normalized ratio correction by 24 h as intravenous therapy. The stable patient with WAC and minor bleeding can also be given oral vitamin K, with correction of the underlying defect. Major bleeding should first be managed with factor replacement for immediate correction of the coagulopathy, using either a prothrombin complex concentrate or fresh-frozen plasma. High-dose vitamin K (10 mg) should be given concurrently via intravenous infusion to confer lasting correction. Warfarin resistance and vitamin K-associated anaphylaxis are rare. Despite development of new oral anticoagulant therapy compounds, warfarin will probably retain a prominent role in thromboembolism management for several years to come.

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

BACKGROUND

The objective of this article is to summarize the published literature concerning the pharmacokinetics and pharmacodynamics of oral anticoagulant drugs that are currently available for clinical use and other aspects related to their management.

METHODS

We carried out a standard review of published articles focusing on the laboratory and clinical characteristics of the vitamin K antagonists; the direct thrombin inhibitor, dabigatran etexilate; and the direct factor Xa inhibitor, rivaroxaban

RESULTS

The antithrombotic effect of each oral anticoagulant drug, the interactions, and the monitoring of anticoagulation intensity are described in detail and discussed without providing specific recommendations. Moreover, we describe and discuss the clinical applications and optimal dosages of oral anticoagulant therapies, practical issues related to their initiation and monitoring, adverse events such as bleeding and other potential side effects, and available strategies for reversal.

CONCLUSIONS

There is a large amount of evidence on laboratory and clinical characteristics of vitamin K antagonists. A growing body of evidence is becoming available on the first new oral anticoagulant drugs available for clinical use, dabigatran and rivaroxaban.

Incidence, clinical impact and risk of bleeding during oral anticoagulation therapy

Bleeding is the most important complication of oral anticoagulation (OAC) with vitamin K-antagonists. Whilst bleeding is unavoidably related to OAC, it may have a great impact on the prognosis of treated subjects by leading to discontinuation of treatment, permanent disability or death. The yearly incidence of bleeding during OAC is 2%-5% for major bleeding, 0.5%-1% for fatal bleeding, and 0.2%-0.4% for intracranial bleeding. While OAC interruption and/or antagonism, as well as administration of coagulation factors, represent the necessary measures for the management of bleeding, proper stratification of the individual risk of bleeding prior to start OAC is of paramount importance. Several factors, including advanced age, female gender, poor control and higher intensity of OAC, associated diseases and medications, as well as genetic factors, have been proven to be associated with an increased risk of bleeding. Most of these factors have been included in the development of bleeding prediction scores, which should now be used by clinicians when prescribing and monitoring OAC. Owing to the many limitations of OAC, including a narrow therapeutic window, cumbersome management, and wide inter- and intra-individual variability, novel oral anticoagulants, such as factor Xa inhibitors and direct thrombin inhibitors, have been recently developed. These agents can be given in fixed doses, have little interaction with foods and drugs, and do not require regular monitoring of anticoagulation. While the novel oral anticoagulants show promise for effective thromboprophylaxis in atrial fibrillation and venous thromboembolism, definitive data on their safety and efficacy are awaited.

Questions and answers on the use of dabigatran and perspectives on the use of other new oral anticoagulants in patients with atrial fibrillation. A consensus document of the Italian Federation of Thrombosis Centers (FCSA)

Dabigatran and other new oral anticoagulants (OAC) represent a step forward in stroke prevention in patients with atrial fibrillation (AF). They indeed have been shown to be an alternative to vitamin K antagonists (VKAs) without the burden of laboratory control. However, these new drugs compete with an effective and well-established therapy, thus bringing about a series of questions and doubts. In this report members of the board of the Italian Federation of Thrombosis Centers (FCSA) answer some questions every clinician might be confronted with.

Bleeding risk and reversal strategies for old and new anticoagulants and antiplatelet agents

The most important adverse effect of antithrombotic treatment is the occurrence of bleeding. In the case of severe bleeding in a patient who uses anticoagulant agents or when a patient on anticoagulants needs to undergo an urgent invasive procedure, it may be useful to reverse anticoagulant treatment. Conventional anticoagulants such as vitamin K antagonists may be neutralized by administration of vitamin K or prothrombin complex concentrates, whereas heparin and heparin derivatives can be counteracted by protamine sulphate. The anti-hemostatic effect of aspirin and other antiplatelet strategies can be corrected by the administration of platelet concentrate and/or desmopressin, if needed. Recently, a new generation of anticoagulants with a greater specificity towards activated coagulation factors as well as new antiplatelet agents have been introduced and these drugs show promising results in clinical studies. A limitation of these new agents may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs, although experimental studies show hopeful results for some of these agents.

Safety of prothrombin complex concentrates for rapid anticoagulation reversal of vitamin K antagonists. A meta-analysis

Prothrombin complex concentrates (PCCs) are recommended as the treatment of choice in warfarin-related coagulopathy. However, the risk of thromboembolic complications associated with their use is not well defined. We performed a meta-analysis to estimate the rate of thromboembolic complications in patients receiving vitamin K antagonists (VKAs) treated with PCCs for bleeding or before urgent surgery. Medline and Embase databases were searched. Two reviewers performed study selection and extracted data independently. Studies providing data on incidence of thromboembolic complications in VKA-treated patients were eligible for the study. Weighted mean proportion of the rate of thromboembolic complications and the mortality rate were calculated. Twenty-seven studies (1,032 patients) were included. Seven studies used 3-factor, and 20 4-factor PCCs. Twelve patients had a thromboembolic complication (weighted mean 1.4%; 95% CI 0.8-2.1), of which two were fatal. The incidence of thromboembolic events was 1.8% (95% CI 1.0-3.0) in patients treated with 4-factor PCCs, and 0.7% (95% CI 0.0-2.4) in patients treated with 3-factor PCCs. Total mortality rate was 10.6% (95% CI 5.9-16.6). In conclusion, our results suggest there is a low but quantifiable risk of thromboembolism in VKA-treated patients receiving PCCs for anticoagulation reversal. These findings should be confirmed in randomised, controlled trials.

Vitamin K antagonists--current concepts and challenges

Vitamin K antagtonists (VKAs) have, for decades, been the corner-stone of anticoagulation in the outpatient setting. While the long half life makes once daily administration practical, close monitoring of VKA effect is necessary because these medicines have a narrow therapeutic index. Despite inter-individual variations in response to VKA doses, the increasing availability of specialized anticoagulation monitoring systems, along with a better understanding of potential drug and dietary interactions, has made the use of VKAs safer and less burdensome. In the future, newer classes of oral anticoagulants and genomic-based dosing strategies may further expand or improve the management options for many patients at risk for thromboembolism.

The practical management of intracerebral hemorrhage associated with oral anticoagulant therapy

Oral anticoagulant-associated intracerebral hemorrhage is increasing in incidence and is the most feared complication of therapy with vitamin K1 antagonists. Anticoagulant-associated intracerebral hemorrhage has a high risk of ongoing bleeding, death, or disability. The most important aspect of clinical management of anticoagulant-associated intracerebral hemorrhage is represented by urgent reversal of coagulopathy, decreasing as quickly as possible the international normalized ratio to values ≤1·4, preferably ≤1·2, together with life support and surgical therapy, when indicated. Protocols for anticoagulant-associated intracerebral hemorrhage emphasize the immediate discontinuation of anticoagulant medication and the immediate intravenous administration of vitamin K1 (mean dose: 10-20 mg), and the use of prothrombin complex concentrates (variable doses calculated estimate circulating functional prothrombin complex) or fresh-frozen plasma (15-30 ml/kg) or recombinant activated factor VII (15-120 μg/kg). Because of cost and availability, there is limited randomized evidence comparing different reversal strategies that support a specific treatment regimen. In this paper, we emphasize the growing importance of anticoagulant-associated intracerebral hemorrhage and describe options for acute coagulopathy reversal in this setting. Additionally, emphasis is placed on understanding current consensus-based guidelines for coagulopathy reversal and the challenges of determining best evidence for these treatments. On the basis of the available knowledge, inappropriate adherence to current consensus-based guidelines for coagulopathy reversal may expose the physician to medico-legal implications.

The c.-1639G>A polymorphism of the VKORC1 gene in Serbian population: retrospective study of the variability in response to oral anticoagulant therapy

A single nucleotide polymorphism c.-1639G>A in the promoter region of vitamin K-epoxide reductase (VKORC1) gene has been found to account for most of the variability in response to oral vitamin K antagonist (VKA). Our aim was to study the effect of c.-1639G>A polymorphism on the acenocoumarol dosage requirements in a group of patients under stable anticoagulation, and to estimate the variability in response to VKA. We conducted a retrospective cohort analysis of 200 stable anticoagulation patients followed from the initiation of VKA. Out of 43 low-dose patients, 40 (93%) carried the A allele. The A allele was less frequent in the group of 30 patients requiring high VKA dose; among these patients 13 (43.3%) carried the A allele in the heterozygous form and none of them carried AA genotype. Patients with GG genotype required 2.6 times higher dose than patients carriers of AA genotype (P < 0.0001). Carriers of AA genotype were more likely to be overanticoagulated during follow-up after initiation of VKA when compared with carriers of the GA and GG genotypes (P < 0.0001). Patients with GG genotype spent more time below therapeutic range compared with patients carriers of AA (P = 0.0328) and GA genotype (P < 0.0001). VKORC1 c.-1639G>A polymorphism significantly influenced VKA dose and represented a good predictor of individuals predisposed to unstable anticoagulation. Pharmacogenetic testing could predict a high risk of overdose among 28.5% of our patients, carriers of AA genotype, before the initiation of anticoagulation.