[Update on point-of-care-based coagulation treatment : Systems, reagents, device-specific treatment algorithms]

Viscoelastic test (VET) procedures suitable for point-of-care (POC) testing are in widespread clinical use. Due to the expanded range of available devices and in particular due to the development of new test approaches and methods, the authors believe that an update of the current treatment algorithms is necessary. The aim of this article is to provide an overview of the currently available VET devices and the associated reagents. In addition, two treatment algorithms for the VET devices most commonly used in German-speaking countries are presented.

[Principles of the perioperative management of direct oral anticoagulants]

Within the approved indications direct oral anticoagulants (DOAC) are increasingly gaining acceptance instead of vitamin K antagonists (VKA). In the last 12 months 5 guidelines relevant to the perioperative management of DOACs have been updated. This article summarizes the current recommendations for the perioperative management of treatment with DOACs. The available substances and their pharmacological properties as well as the possibilities for specific laboratory diagnostics of the effect of DOAC are explained. Special focus is placed on anesthesiologically important aspects of substance-specific preoperative and postoperative intermission intervals, the procedure for neuraxial regional anesthesia and antagonization with specific antidotes in cases of life-threatening bleeding.

Peripheral Neuropathy During Concomitant Administration of Proteasome Inhibitors and Factor Xa Inhibitors: Identifying the Likelihood of Drug-Drug Interactions

Backgrounds: Proteasome inhibitors (PI) cause toxic peripheral neuropathy (PN), which is one of the dose-limiting adverse events of these treatments. Recent preclinical studies find that factor Xa inhibitor (FXaI), rivaroxaban, promotes PN in animals receiving oxaliplatin. Cancer patients can receive combined therapy of PI and FXaI. This study aimed to identify and characterize the interaction signals for the concomitant use of PI and FXaI resulting in PN.

Methods: Reports from the United States FDA Adverse Event Reporting System (FAERS) were extracted from the first quarter of 2004 to the first quarter of 2020 for analysis. The Standardized Medical Dictionary for Regulatory Activities (MedDRA) query was used to identify PN cases. We conducted an initial disproportionality investigation to detect PN adverse event signals associated with the combined use of PI and FXaI by estimating a reporting odds ratio (ROR) with a 95% confidence interval (CI). The adjusted RORs were then analyzed by logistic regression analysis (adjusting for age, gender, and reporting year), and additive/multiplicative models were performed to further confirm the findings. Additionally, subset data analysis was performed on the basis of a single drug of PI and FXaI.

Results: A total of 159,317 adverse event reports (including 2,822 PN reports) were included. The combined use of PI and FXaI was associated with a higher reporting of PN (RORadj = 7.890, 95%CI, 5.321–11.698). The result remained significant based on additive/multiplicative methods. The observed association was consistent in the analysis restricted to all specific PI agents (bortezomib and ixazomib) and FXaI (rivaroxaban), except apixaban.

Conclusion: Analysis of FAERS data identified reporting associations of PN in the combined use of PI and FXaI, suggesting the need for more robust preclinical and clinical studies to elucidate the relationship.

Management of Hemorrhage Related to Direct Action Oral Anticoagulant Medication

Introduction: Direct Oral Anticoagulant – DOACs) are a new class of anticoagulant that directly inhibit the trombine (dabigatran) or Xa factor (rivaroxabane , edoxabane and apixabane) in the coagulation cascade. These medications are being more frequently used for the treatment and prevention of thrombolytic events, mainly in patients with atrial fibrillation, in substitute to varfrine or other vitamin K antagonists (VKAs). Although the incidence of hemorrhage is higher in AVKs than in DOACs, these events may also occur in this group, even in the form of intracranial hemorrhage (ICH), with risk of death. Nowadays, DOACs indications have progressively enhanced and the availability of their specific reverse agents certainly will enhance the safety of their usage. Idarucizumab, reverse agent of dabigatrane, and alpha andexanet, reverse agent of Xa factor, have been approved by the Food and Drug Administration in the United States and ciraparantag may be approved in a near future. Objective: To review the literature on the manage of hemorrhage related to the use of DOACs. Methods: Review of literature that used articles from 1998 to 2017, from several platforms and journals. Conclusion: DOACs constitute a great advance in prophylaxis and treatment of thrombolytic diseases, which presents elevated morbidymortality, and hemorrhages are the main adverse events related to their usage, being rarely necessary the immediate reverse of the anticoagulation. However, the existence of DOACs specific reverse agents enhance the safety of patients, whose anticoagulation may be rapidly reversed if necessary.

Manejo das Hemorragias Relacionadas aos Anticoagulantes Orais de Ação Direta

Introdução: Os anticoagulantes orais diretos (direct oral anticoagulant – DOACs) são uma nova classe de anticoagulantes que inibem diretamente a trombina (dabigatrana) ou o fator Xa (rivaroxabana, edoxabana e apixabana) na cascata da coagulação. Esses estão sendo cada vez mais utilizados para tratamento e prevenção de eventos tromboembólicos, principalmente em pacientes com fibrilação atrial, em substituição à varfarina ou outros antagonistas de vitamina K (AVKs). Embora a incidência de hemorragias seja maior nos AVKs do que nos DOACs, elas também podem ocorrer nesse grupo, até mesmo na forma de hemorragia intracraniana (HIC) com risco de morte. Atualmente as indicações dos DOACs vêm aumentando progressivamente, e a disponibilização de seus agentes reversores específicos certamente aumentará a segurança e, consequentemente, sua utilização. O idarucizumab, reversor da dabigatrana, e o andexanet alfa, reversor dos inibidores do fator Xa, foram aprovados pelo Food and Drug Administration (FDA) dos Estados Unidos e o ciraparantag poderá ser aprovado em um futuro próximo. Objetivo: Revisar a literatura sobre o manejo da hemorragia relacionada ao uso dos DOACs. Métodos: Revisão da literatura que utilizou artigos de 1998 a 2017, de diversas plataformas e revistas. Conclusão: Os DOACs constituem um grande avanço na profilaxia e tratamento da doença tromboembólica, que cursa com elevada morbimortalidade, e as hemorragias são os principais eventos adversos relacionados ao seu uso, sendo raramente necessária a reversão imediata da anticoagulação. No entanto, a existência dos reversores específicos dos DOAcs aumenta a segurança dos pacientes, que poderão ter sua anticoagulação revertida rapidamente, se necessário.

Antithrombotic treatment for secondary prevention of stroke and other thromboembolic events in patients with stroke or transient ischemic attack and non-valvular atrial fibrillation: A European Stroke Organisation guideline

Patients with ischemic stroke or transient ischemic attack and non-valvular atrial fibrillation have a high risk of recurrent stroke and other vascular events. The aim of this guideline is to provide recommendations on antithrombotic medication for secondary prevention of stroke and other vascular outcomes in these patients. The working group identified questions and outcomes, graded evidence, and developed recommendations according to the Grading of Recommendations Assessment, Development, and Evaluation approach and the European Stroke Organisation (ESO) standard operating procedure for guidelines. The guideline was reviewed and approved by the ESO guideline board and the ESO executive committee. In patients with atrial fibrillation and previous stroke or transient ischemic attack, oral anticoagulants reduce the risk of recurrence over antiplatelets or no antithrombotic treatment. Non-vitamin K antagonist oral anticoagulants are preferred over vitamin K antagonists because they have a lower risk of major bleeding and death. Recommendations are weak regarding timing of treatment, (re-)starting oral anticoagulants in patients with previous intracerebral haemorrhage, and treatment in specific patient subgroups of those of older age, with cognitive impairment, renal failure or small vessel disease, because of a lack of strong evidence. In conclusion, for patients with atrial fibrillation and ischemic stroke or transient ischemic attack, non-vitamin K antagonist oral anticoagulants are the preferred treatment for secondary prevention of recurrent stroke or thromboembolism. Further research is required to determine the best timing for initiating oral anticoagulants after an acute ischemic stroke, whether or not oral anticoagulants should be (re)started in patients with a history of intracerebral haemorrhage, and the best secondary preventive treatment in specific subgroups.

Post-transplant diabetes mellitus in patients with solid organ transplants

Solid organ transplantation (SOT) is a life-saving procedure and an established treatment for patients with end-stage organ failure. However, transplantation is also accompanied by associated cardiovascular risk factors, of which post-transplant diabetes mellitus (PTDM) is one of the most important. PTDM develops in 10-20% of patients with kidney transplants and in 20-40% of patients who have undergone other SOT. PTDM increases mortality, which is best documented in patients who have received kidney and heart transplants. PTDM results from predisposing factors (similar to type 2 diabetes mellitus) but also as a result of specific post-transplant risk factors. Although PTDM has many characteristics in common with type 2 diabetes mellitus, the prevention and treatment of the two disorders are often different. Over the past 20 years, the lifespan of patients who have undergone SOT has increased, and PTDM becomes more common over the lifespan of these patients. Accordingly, PTDM becomes an important condition not only to be aware of but also to treat. This Review presents the current knowledge on PTDM in patients receiving kidney, heart, liver and lung transplants. This information is not only for transplant health providers but also for endocrinologists and others who will meet these patients in their clinics.

Apixaban for Primary Prevention of Venous Thromboembolism in Patients With Multiple Myeloma Receiving Immunomodulatory Therapy

Immunomodulatory drugs (IMiDs), including thalidomide, lenalidomide, and pomalidomide, have improved survival of patients with multiple myeloma (MM). However, these therapies are associated with an increased risk of venous thromboembolism (VTE). Apixaban has been approved for treatment of acute VTE and for risk reduction of recurrent VTE following initial therapy. In this phase IV single-arm study (NCT02958969), we aim to prospectively evaluate the safety and efficacy of apixaban for primary prevention of VTE in patients with MM. The primary efficacy objective of this trial is to determine the rate of symptomatic VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE), over 6 months. The primary safety objective is to determine the rate of major bleeding in MM patients receiving apixaban prophylaxis. If proven safe and effective, apixaban will emerge as a promising option for oral VTE prophylaxis in MM patients.

Venous thromboembolism prevention through the use of novel Factor Xa inhibitors

The risk of a venous thromboembolic event is not limited to the pre-hospital, hospital, or immediate post-hospital period. Because of challenges with data collection, the risk of venous thromboembolism (VTE) up to 3 months post-hospitalization for patients with acute and serious medical problems in the setting of chronic disease and/or risk factors for VTE is probably under reported. The growing acceptance and indications of direct oral anticoagulants (DOACs) now includes an indication for VTE prevention for one of the Factor Xa agents. In this paper, the authors explore the issue of VTE in the extended post-hospital period and strategies to provide protection from these morbid and potentially mortal events with oral anticoagulants.

Perceived advantages and disadvantages of oral anticoagulants, and the trade-offs patients make in choosing anticoagulant therapy and adhering to their drug regimen

OBJECTIVE

The objective of this study was to explore the perceived advantages and disadvantages of oral anticoagulant therapies (OAT), and the trade-offs patients make in choosing therapy and adhering to their drug regimen.

METHODS

Five focus group sessions were conducted across Europe among patients with atrial fibrillation to identify the most important factors impacting OAT's value and adherence.

RESULTS

The most frequently identified barriers to OAT were lack of knowledge; poor patient-physician relationships; distraction due to employment or social environment; prior bleeding event(s) or the fear of bleeding; and changes in routine. Factors identified as promoting adherence included patients' personality, motivation, attitudes, and medication-taking habits and routines, as well as good quality health services. Inconvenient aspects of vitamin-K antagonists, such as regular blood monitoring and diet restrictions, were not reported to influence adherence, but may trigger patients to switch to direct oral anticoagulants.

CONCLUSION

Most patients reported that a mixture of modifiable and non-modifiable factors helps them to take their drugs as prescribed. Individual patients' particular needs and preferences regarding OAT vary.

PRACTICE IMPLICATIONS

OAT adherence can be promoted if therapies are tailored to patients' needs and preferences. Patients should be supported to share their preferences with their clinician.

Multi-disciplinary decision making in general practice

Purpose Internationally, healthcare systems are moving towards delivering care in an integrated manner which advocates a multi-disciplinary approach to decision making. Such an approach is formally encouraged in the management of Atrial Fibrillation patients through the European Society of Cardiology guidelines. Since the emergence of new oral anticoagulants switching between oral anticoagulants (OACs) has become prevalent. This case study considers the role of multi-disciplinary decision making, given the complex nature of the agents. The purpose of this paper is to explore Irish General Practitioners' (GPs) experience of switching between all OACs for Arial Fibrillation (AF) patients; prevalence of multi-disciplinary decision making in OAC switching decisions and seeks to determine the GP characteristics that appear to influence the likelihood of multi-disciplinary decision making. Design/methodology/approach A probit model is used to determine the factors influencing multi-disciplinary decision making and a multinomial logit is used to examine the factors influencing who is involved in the multi-disciplinary decisions. Findings Results reveal that while some multi-disciplinary decision-making is occurring (64 per cent), it is not standard practice despite international guidelines on integrated care. Moreover, there is a lack of patient participation in the decision-making process. Female GPs and GPs who have initiated prescriptions for OACs are more likely to engage in multi-disciplinary decision-making surrounding switching OACs amongst AF patients. GPs with training practices were less likely to engage with cardiac consultants and those in urban areas were more likely to engage with other (non-cardiac) consultants. Originality/value For optimal decision making under uncertainty multi-disciplinary decision-making is needed to make a more informed judgement and to improve treatment decisions and reduce the opportunity cost of making the wrong decision.

Chronic kidney disease and anticoagulation: from vitamin K antagonists and heparins to direct oral anticoagulant agents

Anticoagulation in patients with impaired kidney function can be challenging since drugs' pharmacokinetics and bioavailability are altered in this setting. Patients with chronic kidney disease (CKD) treated with conventional anticoagulant agents [vitamin K antagonist (VKA), low-molecular weight heparin (LMWH) or unfractionated heparin (UFH)] are at high risk of bleeding events (both non-major and major clinically relevant bleeding). While anticoagulation reduces the risk of thromboembolic events, the co-existing bleeding risk and the fact that the most commonly used anticoagulation agents are eliminated via the kidneys pose additional challenges. More recently, two classes of direct oral anticoagulant agents (DOACs) have been investigated for the prevention and management of venous thromboembolic events: the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban, and the direct thrombin inhibitor dabigatran. In this review, we discuss the complex challenges and the practical considerations associated with the management of anticoagulation treatment in patients with CKD, with a special focus on DOACs.

Anticoagulation strategies for venous thromboembolism: moving towards a personalised approach

Four non-vitamin K antagonist oral anticoagulants (NOACs) have now been evaluated in clinical trials, providing new therapeutic options for the treatment of venous thromboembolism (VTE). Recent position statements call for a move towards tailored recommendations for the treatment of VTE, to better define in whom and under what conditions a particular anticoagulant may improve clinical outcomes. Here we review the phase III data on NOAC trials for the treatment of VTE, assessing the favourability of agents for particular patient subgroups and aetiologies. Where the data permit, individualised risks of recurrent VTE events and bleeding are presented.

Systemic Disease and Bleeding Disorders for the Oral and Maxillofacial Surgeon

There are multiple systemic diseases that have an impact on coagulation, of which oral and maxillofacial surgeons must be cognizant. Recent evidence has supported the potential for both hypocoagulable and hypercoagulable states in patients with liver and kidney disease with an even less understood impact on prolonged bleeding in the oral cavity. These systemic diseases are not limited to diseases affecting the liver, kidney, and bone marrow; however, these diseases are common among the patient population and surgeons must be capable of making appropriate judgment and modifying care appropriately.

Real-world stroke prevention strategies in nonvalvular atrial fibrillation in patients with renal impairment

BACKGROUND

The data regarding stroke prevention strategies in nonvalvular atrial fibrillation (NVAF) are limited especially in patients with renal impairment (RI). We sought to evaluate management dilemmas in patients with concurrent NVAF and RI in RAMSES (ReAl-life Multicenter Survey Evaluating Stroke Prevention Strategies inTurkey) study.

METHODS

We conducted a prospective, multicenter, nation-wide registry in NVAF patients in outpatient cardiology clinics. All consecutive patients with NVAF were enrolled in RAMSES study (ClinicalTrials.gov identifier NCT02344901). The baseline data were collected. Glomerular filtration rate (GFR) was estimated by Cockcroft-Gault equation.

RESULTS

A total number of 6273 patients from 29 provinces of Turkey with the contribution of 83 investigators were enrolled to the study. Of the study population, 1964(33%) patients had RI which was defined as GFR < 60 mL/min. Patients with RI had significantly higher CHA₂ DS₂ VASc and HAS-BLED scores compared to those without RI (3·9 ± 1·5 vs. 2·9 ± 1·5, and 2·0 ± 1 vs. 1·4 ± 1; P < 0·001). Prior history of major bleeding (6·9% vs. 4·1%, P < 0·001) and stroke (16·2% vs. 11·8%, P < 0·001) was significantly higher among individuals with concomitant RI and NVAF. Although RI patients had a higher risk for thromboembolism, number of the patients who did not receive any anticoagulant therapy was higher in patients with RI than without RI (30·1 vs. 26·4%, P = 0·003).

CONCLUSION

RAMSES study showed that one-third of the patients with NVAF had RI in the real-world setting. Although it is mandatory in most of the patients with concomitant NVAF and RI, nearly one-third of these patients did not receive any anticoagulant therapy.

Risk factors for post-thyroidectomy haemorrhage: a meta-analysis

BACKGROUND

Post-thyroidectomy haemorrhage is a rare but potentially life-threatening and unpredictable complication of thyroid surgery. In this study, we analysed the potential risk factors for the occurrence of post-thyroidectomy haemorrhage.

METHODS

The PubMed and SCIE databases were comprehensively searched for studies published before June 30, 2016. Studies on patients who underwent an open thyroidectomy with or without neck dissection were included, and RevMan 5.3 software was used to analyse the data.

RESULTS

Twenty-five studies and 424 563 patients were included in this meta-analysis, and post-thyroidectomy haemorrhage occurred in 6277 patients (incidence rate = 1.48%). The following variables were associated with an increased risk of post-thyroidectomy haemorrhage: older age (MD = 4.30, 95% CI = 3.09-5.52, P < 0.00001), male sex (OR = 1.73, 95% CI = 1.54-1.94, P < 0.00001), Graves' disease (OR = 1.76, 95% CI = 1.44-2.15, P < 0.00001), antithrombotic agents use (OR = 1.96, 95% CI 1.55-2.49, P < 0.00001), bilateral operation (OR = 1.71, 95% CI = 1.50-1.96, P < 0.00001), neck dissection (OR = 1.53, 95% CI = 1.11-2.11, P = 0.01) and previous thyroid surgery (OR = 1.62, 95% CI = 1.12-2.34, P = 0.01). Malignant tumours (OR = 1.07, 95% CI = 0.89-1.28, P = 0.46) and drainage device use (OR = 1.27, 95% CI = 0.74-2.18, P = 0.4) were not associated with post-thyroidectomy haemorrhage.

CONCLUSION

Our systematic review identified a number of risk factors for post-thyroidectomy haemorrhage, including older age, male sex, Graves' disease, antithrombotic agents use, bilateral operation, neck dissection and previous thyroid surgery. Early control of modifiable risk factors could improve patient outcomes and satisfaction.

Appropriateness of direct oral anticoagulant dosing for venous thromboembolism treatment

Adherence to FDA-approved dosing for the direct oral anticoagulants (DOACs) based on renal function, hepatic function, and concomitant medications in a real-world setting has not been evaluated. The purpose of this retrospective cohort analysis was to determine the prescribing accuracy of DOAC dosing for venous thromboembolism (VTE) treatment compared with enoxaparin. The secondary outcomes were to describe the incidence of in-hospital VTE recurrence and bleeding on DOAC therapy. The study included 168 patients with 261 admissions for the DOAC group and 639 patients with 841 admissions for the enoxaparin group. Dosing was appropriate in 235/261 (90.0%) of patient admissions in the DOAC group. Among the DOAC doses administered, 233/2246 (10.4%) were contraindicated based on renal function, hepatic function, or drug interactions compared with 322/7293 (4.4%) of administered enoxaparin doses evaluated based on renal function, p < 0.001. Three recurrent VTEs, 3 major bleeding events, 1 probable major bleeding event, and 3 clinically relevant non-major bleeding events were observed during the study period. Although a majority of DOAC doses administered were appropriate, further education and close monitoring of these agents are warranted to increase appropriateness of therapy and improve patient safety.

Risk-Benefit Profile of Direct-Acting Oral Anticoagulants in Established Therapeutic Indications: An Overview of Systematic Reviews and Observational Studies

Since 2008, the direct-acting oral anticoagulants (DOACs) have expanded the therapeutic options of cardiovascular diseases with recognized clinical and epidemiological impact, such as non-valvular atrial fibrillation (NVAF) and venous thromboembolism (VTE), and also in the preventive setting of orthopedic surgical patients. The large body of evidence, not only from pivotal clinical trials but also from 'real-world' postmarketing observational findings (e.g. analytical epidemiological studies and registry data) gathered to date allow for a first attempt at verifying a posteriori whether or not the pharmacological advantages of the DOACs actually translate into therapeutic innovation, with relevant implications for clinicians, regulators and patients. This review aims to synthesize the risk-benefit profile of DOACs in the aforementioned consolidated indications through an 'evidence summary' approach gathering the existent evidence-based data, particularly systematic reviews with meta-analyses of randomized controlled trials, as well as observational studies, comparing DOACs with vitamin K antagonists. Clinical evidence will be discussed and compared with major international guidelines to identify whether an update is needed. Controversial clinically relevant safety issues will be also examined in order to highlight current challenges and unsettled questions (e.g. actual bleeding risk in susceptible populations). It is anticipated that the large number of publications on NVAF or VTE (44 systematic reviews with meta-analyses and 12 observational studies retained in our analysis) suggests the potential existence of overlapping studies and calls for common criteria to qualitatively and quantitatively assess discordances, thus guiding future research.

New oral anticoagulants in patients with cancer: current state of evidence

Effectiveness of new oral anticoagulants (NOAC) in patients with cancer is not clearly defined. There remain concerns of doubtful benefit and chances of potential harm with newer agents. In this meta-analysis, we evaluated the efficacy and safety of NOAC in patients with cancer. PubMed, Cochrane Library, EMBASE, Web of Science, and CINAHL databases were searched from January 01, 2001 through February 28, 2013. Randomized controlled trials reporting efficacy and safety data of NOACs (rivaroxaban, dabigatran, and apixaban) with control (low-molecular-weight heparin/vitamin K antagonists/placebo) for patients with cancer were included. Primary efficacy outcome was venous thromboembolism (VTE) or VTE-related death, and primary safety outcome was clinically relevant bleeding. We used random-effects models. Six trials randomized 19,832 patients, and 1197 patients had cancer. Risk of VTE or VTE-related death was not significantly different with NOAC versus control [odds ratio (OR), 0.80; 95% confidence interval (CI), 0.39-1.65] in patients with cancer. Separate analysis for individual effects showed similar results for rivaroxaban (OR, 1.08; 95% CI, 0.60-1.94) and dabigatran (OR, 0.91; 95% CI, 0.21-3.91). Clinically relevant bleeding was not higher with NOAC compared with control (OR, 1.49; 95% CI, 0.82-2.71); individual effect of rivaroxaban showed similar results. No statistically significant difference of efficacy and safety with NOAC was found between patients with and without cancer. Rivaroxaban might be equally effective and safe as vitamin K antagonist in patients with cancer. Dabigatran is as effective as comparator; however, safety profile of dabigatran is unknown. Randomized trials of new anticoagulants specific to the cancer population are necessary, and NOAC also need to be evaluated against low-molecular-weight heparin.

Challenges and Treatment for Stroke Prophylaxis in Patients with Atrial Fibrillation in Mexico: A Review

Atrial fibrillation (AF) is associated with an increased risk of stroke. AF-related strokes cause greater disability and mortality than those in patients without AF, and are associated with a significant clinical and economic burden in Mexico. Antithrombotic therapy reduces stroke risk in patients with AF and is recommended for all patients except those classified as having a low stroke risk. However, its use is suboptimal all around the world; one study showed that only 4 % of Mexican patients with AF who presented with ischemic stroke were in the therapeutic range for anticoagulation. Vitamin K antagonists (VKAs) such as warfarin or acenocoumarin have long been the only oral anticoagulants for stroke prevention in AF. Although effective, VKAs have disadvantages, including the need for regular coagulation monitoring and dose adjustment. Interactions with numerous common medications and foods contribute to the risk of serious bleeding and thrombotic events in VKA-treated patients. Thus novel oral anticoagulants (NOACs), more properly called direct oral anticoagulants (DOACs), such as dabigatran etexilate, rivaroxaban, apixaban, and edoxaban (not available in Mexico), have been developed. These offer the convenience of fixed-dose treatment without the need for monitoring, and have few drug or food interactions. Pivotal phase III trials have demonstrated that these agents are at least as effective as warfarin in preventing stroke and are associated with a reduced risk of intracranial hemorrhage. With apixaban approved in Mexico in April 2013, clinicians now have the choice of three novel DOACs as alternatives to warfarin. However, it is yet to be established which of these agents should be the first choice, and treatment decisions are likely to depend on the individual patient's characteristics.

Suboptimal Use of Oral Anticoagulants in Atrial Fibrillation: Has the Introduction of Direct Oral Anticoagulants Improved Prescribing Practices?

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) and the associated risk of stroke are emerging epidemics throughout the world. Suboptimal use of oral anticoagulants for stroke prevention has been widely reported from observational studies. In recent years, direct oral anticoagulants (DOACs) have been introduced for thromboprophylaxis. We conducted a systematic literature review to evaluate current practices of anticoagulation in AF, pharmacologic features and adoption patterns of DOACs, their impacts on proportion of eligible patients with AF who receive oral anticoagulants, persisting challenges and future prospects for optimal anticoagulation.

LITERATURE SOURCE AND SELECTION CRITERIA

In conducting this review, we considered the results of relevant prospective and retrospective observational studies from real-world practice settings. PubMed (MEDLINE), Scopus (RIS), Google Scholar, EMBASE and Web of Science were used to source relevant literature. There were no date limitations, while language was limited to English. Selection was limited to articles from peer reviewed journals and related to our topic.

RESULTS

Most studies identified in this review indicated suboptimal use of anticoagulants is a persisting challenge despite the availability of DOACs. Underuse of oral anticoagulants is apparent particularly in patients with a high risk of stroke. DOAC adoption trends are quite variable, with slow integration into clinical practice reported in most countries; there has been limited impact to date on prescribing practice.

CONCLUSION

Available data from clinical practice suggest that suboptimal oral anticoagulant use in patients with AF and poor compliance with guidelines still remain commonplace despite transition to a new era of anticoagulation featuring DOACs.

Renal function in atrial fibrillation patients switched from warfarin to a direct oral anticoagulant

All available direct oral anticoagulants (DOACs) are at least partially eliminated by the kidneys. These agents are increasingly being used as alternatives to warfarin for stroke prevention in patients with atrial fibrillation. The aim of this study was to identify changes in renal function and associated DOAC dosing implications in a multicenter cohort of atrial fibrillation patients switched from warfarin to DOAC treatment. We included all patients in the Michigan Anticoagulation Quality Improvement Initiative cohort who switched from warfarin to a DOAC with atrial fibrillation as their anticoagulant indication between 2009 and 2014, and who had at least two creatinine values. Compliance with FDA-recommended dosing based on renal function was assessed. Of the 189 patients switched from warfarin to a DOAC, 34 (18.0 %) had a baseline creatinine clearance <50 mL/min and 23 (12.2 %) experienced important fluctuations in renal function. Of these 23 patients, 6 (26.1 %) should have impacted the DOAC dosing, but only 1 patient actually received an appropriate dose adjustment. Additionally, 15 (7.9 %) of patients on DOACs had a dose change performed, but only one patient demonstrated a change in renal function to justify the dose adjustment. Most atrial fibrillation patients who switched from warfarin to a DOAC had stable renal function. However, the majority of patients who had a change in renal function did not receive the indicated dose change. As the use of DOACs expands, monitoring of renal function and appropriate dose adjustments are critical.

Efficacy of prothrombin complex concentrates for the emergency reversal of dabigatran-induced anticoagulation

Dabigatran is effective in decreasing the risk of ischaemic stroke in patients with atrial fibrillation. However, like all anticoagulants, it is associated with a risk of bleeding. In cases of trauma or emergency surgery, emergency reversal of dabigatran-induced anticoagulation may be required. A specific reversal agent for dabigatran, idarucizumab, has been approved by the US Food and Drug Administration. Alternative reversal agents are available, such as prothrombin complex concentrates (PCCs) and activated PCCs (aPCCs). In this review we evaluate the role of PCCs and aPCCs in the reversal of dabigatran anticoagulation and consider which tests are appropriate for monitoring coagulation in this setting. Pre-clinical studies, small clinical studies and case reports indicate that PCCs and aPCCs may be able to reverse dabigatran-induced anticoagulation in a dose-dependent manner. However, dosing based on coagulation parameters can be difficult because available assays may not provide adequate sensitivity and specificity for measuring anticoagulation induced by dabigatran or the countering effects of PCCs/aPCCs. In addition, PCCs or aPCCs can potentially provoke thromboembolic complications. Despite these limitations and the fact that PCCs and aPCCs are not yet licensed for dabigatran reversal, their use appears to be warranted in patients with life-threatening haemorrhage if idarucizumab is not available.

Oral anticoagulants and risk of nephropathy

Anticoagulant-related nephropathy, a recently recognized entity, manifests as unexplained acute kidney injury in the setting of excessive anticoagulation with oral agents. Histologic findings in warfarin-related nephropathy include glomerular hemorrhage and renal tubular obstruction by red blood cells. Affected patients are at increased risk of mortality as well as irreversible kidney injury. Patients with chronic kidney disease are particularly vulnerable to this complication. Similar case reports of anticoagulant-related nephropathy have been linked to the more novel oral anticoagulant, dabigatran. Anticoagulant-related nephropathy has been successfully reproduced in rat models. These animal models shed light on the pathogenesis of the disease including the potential role of direct thrombin and protease-activated receptor-1 inhibition. Warfarin and dabigatran also cause an increase in systolic blood pressure in rats, a risk factor for developing nephropathy. This article reviews the current evidence for anticoagulant-related nephropathy and provides data for the suggested possible mechanisms underlying this adverse effect.

New oral anticoagulants - a guide for ENT surgeons

BACKGROUND

New oral anticoagulants have been developed to overcome the perceived disadvantages of more traditional anticoagulants such as heparin and warfarin, and their use amongst ENT patients have been increasing.

OBJECTIVES

This review article aims to discuss the mechanism of action of new oral anticoagulants, when they should be used and a protocol for their use, in both the bleeding patient and in the peri-operative setting.

CONCLUSION

It is important that ENT surgeons are aware of the use of new oral anticoagulants, and have a departmental- and trust-based policy on their use and reversal in bleeding and surgical patients.

Monitoring anticoagulant therapy with new oral agents

Thromboembolic disease is a major leading cause of mortality and morbidity in industrialized countries. Currently, the management of these patients is challenging due to the availability of new drugs with proven efficacy and security compared to traditional oral vitamin K antagonists. These compounds are characterized by a predictable pharmacokinetic profile for which blood monitoring is not routinely needed. Nevertheless, some data have suggested inter-patient variability in the anticoagulant effect of these drugs, raising concerns about their effectiveness and safety. Although mass-spectrometry is the gold standard to determine drug plasma concentrations, this method is not widely available in every-day practice and some coagulation assays are commonly used to determine the anticoagulant effect of these drugs. The present review aims to summarize the current knowledge regarding the clinical question of how and when to monitor patients with new anticoagulant oral agents.

Different risk factors for bleeding and discontinuation between dabigatran and rivaroxaban

BACKGROUND

It is unclear whether risk factors for bleeding and discontinuation are different between dabigatran and rivaroxaban.

METHODS AND RESULTS

We enrolled consecutive patients with atrial fibrillation who received dabigatran or rivaroxaban, had a CHADS2 score >1 and creatinine clearance >30ml/min. During this period, only dabigatran and rivaroxaban were available as non-vitamin K oral anticoagulants (NOACs) in our hospital. We compared the clinical and demographic data and the incidence of bleeding for one year between dabigatran group and rivaroxaban group. As a result, the dabigatran group consisted of 177 patients and the rivaroxaban group consisted of 179 patients. The incidence of discontinuation was significantly higher in the dabigatran group than in the rivaroxaban group (27.7% vs. 13.4%, p<0.001). Multivariate analysis, even after propensity score-matching analysis, revealed that there were no independent risk factors for bleeding in the dabigatran group, while in the rivaroxaban group, use of antiplatelet therapy was an independent factor correlating with bleeding.

CONCLUSIONS

The risk factors for bleeding may be different between dabigatran and rivaroxaban. To avoid bleeding, rivaroxaban should be prescribed with caution or avoided in patients using antiplatelet therapy. Upon discontinuation, rivaroxaban may be more favorable than dabigatran.

Use Patterns and Unlabeled Uses of Target-Specific Oral Anticoagulants

Background: Target-specific oral anticoagulants (TSOAs) have advantages and disadvantages over warfarin, and they differ by indication, dosage adjustment, and drug interactions. Objective: The purpose of this retrospective cohort study is to determine use patterns and unlabeled uses of TSOAs. Methods: From July 1, 2012, to April 30, 2014, orders for warfarin, dabigatran, rivaroxaban, or apixaban in a tertiary medical center were included. Electronic medical records were reviewed to collect information regarding characteristics of the patients receiving these medications. Unlabeled use was defined as an indication or dose not approved by the US Food and Drug Administration. The percentage of orders for each study drug per month and the percentage of orders for each TSOA that contained an unlabeled use were calculated. Results: Of a total of 869 orders, 140 (16.1%) were for TSOAs (13 dabigatran, 97 rivaroxaban, and 30 apixaban orders). Compared with the first 4 months of the study period, the monthly percentage of orders for a TSOA increased by 2.5-fold in the last 4 months. Of the 3 TSOAs, only orders for dabigatran decreased (5.6% in July 2012 vs 0% in April 2014). Of the 140 TSOA orders, 28 (20.0 %) were unlabeled uses (3 unlabeled indications and 25 unlabeled dose), which included 16 unlabeled renally adjusted doses. The percentage of unlabeled uses did not significantly differ by TSOA. Conclusion: The use of TSOAs has increased and unlabeled uses are common. These data provide opportunities for quality improvement in the use of TSOA in clinical practice.

New Oral Anticoagulants: How Do We Use Them Wisely?

The relative efficacy and safety of new oral anticoagulants (NOAC) have been consistent across a wide range of patients in clinical trials. On the one hand, they have offered new therapeutic options for stroke prevention in patients with atrial fibrillation (AF) and patients do like the experience of no need of frequent blood draws. On the other hand, their expensive prices, different formulary plans from different insurance companies, lack of antidote, and no method of monitoring the therapy are some of the challenges on their use in clinical practice. This narrative review aims to help clinicians understand these new oral anticoagulants better and choose them wisely according to their indications. In addition, other issues related to the use of NOAC, such as cost and methods of reversing their effects in hemorrhagic conditions, are also discussed.

Long-term outcome of liver transplant patients with Budd-Chiari syndrome secondary to myeloproliferative neoplasms

BACKGROUND

A considerable proportion of patients receiving liver transplants for Budd-Chiari syndrome (BCS) suffer from myeloproliferative neoplasms (MPN). This study evaluated the long-term prognosis of liver-transplanted patients with BCS secondary to MPN and the effect of immunosuppression on MPN progression.

METHODS

A total of 78 patients with BCS were evaluated between 1982 and 2013. Of those, 40 patients suffered from polycythaemia vera (PV) and essential thrombocythaemia (ET). One patient had primary myelofibrosis (PMF). All patients received the standard immunosuppressive regimen. We retrospectively evaluated the long-term survival, clinical course and laboratory parameters of patients with MPN.

RESULTS

Exactly 29/41 patients (71%) with MPN survived ≥ 3 years [mean age 36 ± 11 years; females n = 27 (93%)]. Mean follow-up after orthotopic liver transplantation (OLT) was 12.4 ± 7.3 years (range 3-28 years). Five- and 10-year survival rates were not significantly different in patients with and without MPN (P = 0.81 and P = 0.66 respectively) or in patients with PV and ET (P = 0.29 and P = 0.55 respectively). Thrombosis and bleeding developed in 7/29 (24%) long-term MPN survivors with no significant difference between ET and PV (P = 0.18). In the long-term follow-up, there was no evidence of progression to overt myelofibrosis or acute myeloid leukaemia (AML). In the uni- and multivariate Cox-regression analyses, MPN did not influence survival after OLT.

CONCLUSIONS

Budd-Chiari syndrome patients with and without underlying MPN had similar long-term survival rates after OLT. There was no evidence of enhanced progression of MPN after OLT secondary to immunosuppressive therapy. However, major haemorrhage and recurrent thrombosis contributed to morbidity and mortality after OLT in those patients.

Oral anticoagulation: a critique of recent advances and controversies

There have recently been significant advances in the field of oral anticoagulation, but these have also led to many controversies. Warfarin is still the commonest drug used for clotting disorders but its use is complicated owing to wide inter-individual variability in dose requirement and its narrow therapeutic index. Warfarin dose requirement can be influenced by both genetic and environmental factors. Two recent randomized controlled trials (RCTs) came to different conclusion regarding the utility of genotype-guided dosing; we critically explore the reasons for the differences. The new generation of oral anticoagulants have been demonstrated to be as efficacious as warfarin, but further work is needed to evaluate their safety in real clinical settings.

Treatment options for venous thromboembolism: lessons learnt from clinical trials

Venous thromboembolism (VTE), comprising deep vein thrombosis and pulmonary embolism, is a common condition associated with a significant clinical and economic burden. Anticoagulant therapy is the mainstay of treatment for VTE, having been shown to reduce the risk of death in patients with pulmonary embolism, and recurrence or extension of thrombi in patients with deep vein thrombosis during the initial treatment period. Long-term anticoagulation is indicated in some individuals with VTE, depending on individual risk of VTE recurrence and anticoagulant-related bleeding. Management of VTE in clinical practice is often complex because patients' characteristics and treatment needs may differ considerably from those encountered in clinical trials. Current guidelines recommend the use of either low molecular weight heparins or fondaparinux overlapping with and followed by a vitamin K antagonist for the initial treatment of VTE, with the vitamin K antagonist continued when long-term anticoagulation is required. These traditional anticoagulants have practical limitations that have led to the development of direct oral anticoagulants that directly target either Factor Xa or thrombin and are administered at a fixed dose without the need for routine coagulation monitoring. This review discusses practical considerations for hospital physicians and haematologists in the management of VTE treatment, including the potential for the direct oral anticoagulants to simplify treatment.

Efficacy and safety of novel oral anticoagulants in clinical practice: a report from three centers in Sweden

Introduction

In clinical trials new oral anticoagulants (NOAC) have proved to be as effective as warfarin for thromboprophylaxis in atrial fibrillation. The aim of this study was to evaluate the efficacy and safety of these drugs in clinical practise.

Methods and results

All patients treated with new oral anticoagulants at Skåne University hospital and Halland County Hospital Halmstad between 2009 and September 2013 was identified in the Swedish national quality registry for atrial fibrillation and anticoagulation (AuriculA). Medical records were reviewed to identify thromboembolism and major bleeding and compared to a warfarin cohort with a time in therapeutic range (TTR) of 76%. There were 826 patients, mean age 70.6, follow up 591 years, with atrial fibrillation treated with NOAC. Dabigatran was the initial drug in 79% of the cohort. The incidences of ischemic stroke/ TIA and major bleeding were 1.9 (95% CI; 1.0-3.2) and 2.0 (95% CI; 1.1-3.5) per 100 patient-years respectively. The corresponding incidences for warfarin were 1.5 (95% CI; 1.0-2.2) and 2.5 (95% CI; 1.8-3.3), with no statistical significance between the groups. Two subdural hematomas occurred 0.4 (95% CI; 0.06-1.1) per 100 patient-years. Mean age of patients with complications was 77.9 (±5.9) and 69.3 (±11.3) for those without (p < 0.001). The discontinuation rate was 6.5% and 1.7% was due to dyspepsia for dabigatran, lower than the RE-LY trial.

Conclusion

This study, largely based on dabigatran shows that treatment is efficient and safe in everyday clinical practice and not significantly different compared to a warfarin cohort with tight anticoagulation control.

Electronic supplementary material

The online version of this article (doi:10.1186/s12959-014-0029-6) contains supplementary material, which is available to authorized users.

Anticoagulation in patients with impaired renal function and with haemodialysis. Anticoagulant effects, efficacy, safety, therapeutic options

Patients with impaired renal function are exposed to an increased risk for bleeding complications depending on the amount of the anticoagulant eliminated by the kidneys. The elimination of unfractionated heparins, vitamin K antagonists and argatroban is only minimally influenced by a reduced renal function. Low-molecular weight heparins, fondaparinux, danaparoid, hirudins and non-vitamin K antagonist oral anticoagulants (NOAC) cause a variably increased bleeding risk in renal impairment. Dose reductions are recommended for all of these anticoagulants in renal impairment, some are even contraindicated at certain levels of renal impairment. Their benefit over the conventional anticoagulants is preserved if renal dosing is employed. For end-stage renal disease patients specific treatment regimens are required.

Warfarin versus dabigatran etexilate: an assessment of efficacy and safety in patients with atrial fibrillation

INTRODUCTION

Oral anticoagulation is the mainstay for stroke and thromboembolic event prevention in patients with atrial fibrillation (AF). Given limitations of warfarin therapy, non-vitamin K oral anticoagulants have been developed including direct thrombin inhibitors (i.e., dabigatran etexilate). Dabigatran etexilate has been tested thoroughly in terms of efficacy and safety in clinical trials and studies, involving 'real-world' cohorts. In this review, currently available evidence in patients with non-valvular AF is discussed.

AREAS COVERED

The pharmacology, efficacy and safety, and current aspects of use of dabigatran etexilate in patients with non-valvular AF are reviewed in a comparative manner to warfarin both for chronic anticoagulation and in different clinical settings.

EXPERT OPINION

Dabigatran etexilate appeared to have several pharmacokinetic and pharmacodynamic advantages over warfarin, as well as a favorable efficacy and safety profile being at least noninferior and often superior to warfarin in patients with non-valvular AF. The latter was shown in the clinical trials, meta-analyses and studies with 'real-world' data. Currently ongoing trials will expand the body of evidence on warfarin and will aid decision making in currently controversial areas. Important limitations of dabigatran etexilate include contraindications for its use in patients with prosthetic heart valves and end-stage chronic kidney disease.

Current state of anticoagulants to treat deep venous thrombosis

Anticoagulation remains the cornerstone of treatment in patients with deep vein thrombosis (DVT). While parenteral anticoagulants and oral vitamin K antagonists (e.g., warfarin) have been used for many decades, the recent development of novel oral anticoagulants have provided clinicians with an expanding set of therapeutic options for DVT. This review summarizes the pharmacology and clinical trial results of these new oral anticoagulants. Several practical considerations to the use of these oral anticoagulants including issues related to adherence, monitoring, and reversal are also discussed.

Dynamics of vitamin K antagonist and new oral anticoagulants use in atrial fibrillation: a Danish drug utilization study

BACKGROUND

Detailed data on real-life utilization of vitamin K antagonists (VKAs) and new oral anticoagulants (NOACs) in atrial fibrillation are sparse.

OBJECTIVES

To describe the dynamics of VKA and NOAC use: that is, (i) how patients moved in and out of, as well as between, use of VKAs and NOACs; (ii) how patients adhered to treatment; and (iii) which type of prescriber initiated, maintained, and changed treatment with VKAs and NOACs.

METHODS

We conducted a drug utilization study in the region of southern Denmark (population 1.2 million) using prescription data. We included all subjects using VKAs or NOACs during the period of August 22, 2011, through June 30, 2013, restricted to subjects with a diagnosis of atrial fibrillation.

RESULTS

We identified 20,911 subjects, of whom 20,769 and 1639 used VKAs and NOACs, respectively. The number of VKA users was stable at ~ 14,000 subjects during the study period, whereas the number of NOAC users increased to 903. The majority of NOAC users had previously used VKAs (n = 974), whereas 389 anticoagulant-naïve users initiated NOAC therapy. Among the latter, 51.2% had changed to VKAs within 6 months. 57.3% of VKA users were initiated by a hospital physician, whereas maintenance treatment was predominantly handled by the patient's general practitioner (97.6%). Switches from NOAC to VKA were initiated by a general practitioner in 69.2% of the cases. For users of NOACs, these numbers were 73.5%, 94.0%, and 63.3%.

CONCLUSIONS

A large proportion of NOAC users switch to a VKA within a short time frame. The reasons for this are not clear.

New oral anticoagulants: clinical indications, monitoring and treatment of acute bleeding complications

New oral anticoagulants like the direct thrombin inhibitor, dabigatran (Pradaxa®), and factor Xa-inhibitors, rivaroxaban (Xarelto®) and apixaban (Eliquis®) are available for prophylaxis and treatment of thromboembolic disease. They are emerging alternatives to warfarin and provide equal or better clinical outcome together with reduced need for routine monitoring. Methods for measuring drug concentrations are available, although a correlation between plasma drug concentrations and the risk of bleeding has not been firmly established. Standard laboratory measures like prothrombin time and activated partial thromboplastin time are not sensitive enough to detect thrombin or factor Xa inhibition provided by new oral anticoagulants. Thus, these standard tests may only be used as a crude estimation of the actual anticoagulation status. Further challenges regarding patients receiving new oral anticoagulants who presents with major bleeding or need for emergency surgery pose a unique problem. No established agents are clinically available to reverse the anticoagulant effect, although preclinical data report prothrombin complex concentrate as more efficient than fresh frozen plasma or other prohaemostatic agents. This review summaries current knowledge on approved new oral anticoagulants and discusses clinical aspects of monitoring, with particular focus on the management of the bleeding patient.

Treatment of patients with acute deep vein thrombosis and/or pulmonary embolism: efficacy and safety of non-VKA oral anticoagulants in selected populations

Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), presents a large clinical burden. Prompt, effective and sustained anticoagulation is vital because of the risk of recurrent events, including life-threatening PE, and complications such as post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension. Dual-drug standard therapy is effective; however, parenteral low molecular weight heparin, coupled with routine coagulation monitoring and dose adjustment of vitamin K antagonists (VKAs), presents challenges for patients and healthcare providers. Non-VKA oral anticoagulants provide a simplified option for VTE treatment. Phase III studies have investigated rivaroxaban and apixaban as single-drug approaches, and edoxaban and dabigatran in conjunction with initial heparin therapy. These agents demonstrated non-inferiority to standard therapy, and most showed significant reductions in major bleeding. However, clinical information is limited in patient subgroups, e.g. fragile patients or patients with renal impairment or cancer, who may be at higher risk of bleeding and/or VTE. A prespecified pooled analysis of the EINSTEIN DVT and EINSTEIN PE studies (8281 patients), undertaken to evaluate clinical outcomes with rivaroxaban versus standard therapy, confirmed the non-inferiority of rivaroxaban, with significant reductions in major bleeding and fewer intracranial and retroperitoneal bleeding events. Consistent efficacy and safety were observed with rivaroxaban, irrespective of fragility, cancer or clot severity. The introduction of the non-VKA oral anticoagulants and approval of rivaroxaban in the EU, US and Canada for the treatment and secondary prevention of DVT and PE offer the potential for improvements in effective care across a broad spectrum of patients with VTE.

Safety of new oral anticoagulant drugs: a perspective

The recent development of new oral anticoagulants (NOACs) offers the possibility of efficacy, relative safety and convenience compared with warfarin. This could lead to greater patient compliance, with easier management and improved provision of thromboprophylaxis. Safety whilst using NOACs should be focused on bleeding cases, surgery or on the management of patients receiving anticoagulant therapy with concomitant impairment of renal function, especially since many NOACs are dependent on renal excretion. Thus, if the clearance creatinine indicates severe renal impairment, NOACS will be contraindicated or their dose needs to be changed. In patients who need surgery, there are published protocols of management, depending on the severity of the intervention and renal function. In the case of severe hemorrhage, requiring rapid reversal of the anticoagulant effect and in the absence of specific antidotes, alternatives such as one of the nonspecific haemostatic agents must be considered. Clinical evaluation in bleeding situations and a meticulous risk-benefit appraisal for NOACs is needed, and these procoagulant agents and patients must be monitored closely. This article provides an overview of the pharmacology and potential risks, as well as the efficacy and safety of NOACs.

Extraosseous calcification in end-stage renal disease: from visceral organs to vasculature

In earlier days, periarticular accumulations of calcium phosphate causing tumor-like depositions were considered the result of passive precipitation and referred to as metastatic calcifications. From sophisticated computer tomographic studies and growing insight, we have learned that calcifications in the cardiovascular system are far more threatening and in fact one of the most important sequela of end-stage renal disease. The histologic characteristic of uremia-related calcification is arteriosclerosis of the media. In addition, there is atherosclerosis of the intima, due to the high prevalence of classic cardiovascular risk factors in renal disease. The two vascular features can frequently exist at different sites in the vasculature. Novel diagnostic techniques are helping to elucidate the pathogenetic mechanisms of active conversion of vascular smooth muscle cells to osteochondritic cells. Through this process, extensive calcification of the central and peripheral vasculature ensues, influenced by different promotors and inhibitors. Calciphylaxis is a special form of extraosseous calcification leading to skin necrosis. The factors that trigger the development of calciphylaxis are not completely understood, but this syndrome shares part of the pathophysiologic basis of extraosseous calcification in general. However, the therapeutic approach must be prompt and aggressive, because of the poor prognosis. Frequently, a fatal outcome cannot be avoided in calciphylaxis.