How I treat with anticoagulants in 2012: new and old anticoagulants, and when and how to switch. Blood. 2012;119:3016-3023. [PMID: 22302737 DOI: 10.1182/blood-2011-10-378950]

Fibrin(ogen) Is Constitutively Expressed by Differentiated Intestinal Epithelial Cells and Mediates Wound Healing

Fibrinogen is a large molecule synthesized in the liver and released in the blood. Circulating levels of fibrinogen are upregulated after bleeding or clotting events and support wound healing. In the context of an injury, thrombin activation drives conversion of fibrinogen to fibrin. Fibrin deposition contains tissue damage, stops blood loss, and prevents microbial infection. In most circumstances, fibrin needs to be removed to allow the resolution of inflammation and tissue repair, whereas failure of this may lead to the development of various disorders. However, the contribution of fibrinogen to tissue inflammation and repair is likely to be context-dependent. In this study, the concept that fibrin needs to be removed to allow tissue repair and to reduce inflammation is challenged by our observations that, in the intestine, fibrinogen is constitutively produced by a subset of intestinal epithelial cells and deposited at the basement membrane as fibrin where it serves as a substrate for wound healing under physiological conditions such as epithelial shedding at the tip of the small intestinal villus and surface epithelium of the colon as well as under pathological conditions that require rapid epithelial repair. The functional integrity of the intestine is ensured by the constant renewal of its simple epithelium. Superficial denuding of the epithelial cell layer occurs regularly and is rapidly corrected by a process called restitution that can be influenced by various soluble and insoluble factors. Epithelial cell interaction with the extracellular matrix greatly influences the healing process by acting on cell morphology, adhesion, and migration. The functional contribution of a fibrin(ogen) matrix in the intestine was studied under physiological and pathological contexts. Our results (immunofluorescence, immunoelectron microscopy, and quantitative PCR) show that fibrin(ogen) is a novel component of the basement membrane associated with the differentiated epithelial cell population in both the small intestine and colon. Fibrin(ogen) alone is a weak ligand for epithelial cells and behaves as an anti-adhesive molecule in the presence of type I collagen. Furthermore, the presence of fibrin(ogen) significantly shortens the time required to achieve closure of wounded epithelial cell monolayers and co-cultures in a PI3K-dependent manner. In human specimens with Crohn’s disease, we observed a major accumulation of fibrin(ogen) throughout the tissue and at denuded sites. In mice in which fibrin formation was inhibited with dabigatran treatment, dextran sulfate sodium administration provoked a significant increase in the disease activity index and pathological features such as mucosal ulceration and crypt abscess formation. Taken together, these results suggest that fibrin(ogen) contributes to epithelial healing under both normal and pathological conditions.

Expert Recommendations on the Usage of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) from India: Current Perspective and Future Direction

Non-vitamin K antagonist oral anticoagulants (NOACs) are a new class of anticoagulant drugs used in the prevention and treatment of venous thromboembolism (VTE) and atrial fibrillation (AF). Anticoagulation requires the integration of the correct type and dose of oral anticoagulants based on patient characteristic, and therefore therapy needs to be individualized for each patient. Growing scientific evidence from studies on NOACs has led to a better understanding of their benefits and safety. A large amount of available data creates a necessity for an adaptable practical document for the usage of NOACs in India. The current consensus, developed by experts from India, aims to give recommendations on various frequently raised clinical questions with regards to NOACs and its usage. This practical document provides a platform upon which future guidelines, policies, training, and education for the use of NOACs can be tailored.

The Effect of Cardiovascular Medications on Disease-Related Outcomes in Idiopathic Pulmonary Fibrosis: A Systematic Review and Meta-Analysis

Background: Multiple studies have revealed that idiopathic pulmonary fibrosis (IPF) patients are more at risk for cardiovascular diseases and that many IPF patients receive cardiovascular medications like statins, angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), and anticoagulants. Existing studies have reported divergent findings on the link between cardiovascular medications and fibrotic disease processes. The aim of this study is to synthesize the evidence on the efficacy of cardiovascular medications in IPF. Methods: We searched studies reporting the effect of cardiovascular medications on IPF in the PubMed, Embase, Web of Science, Cochrane Library, and two Chinese databases (China National Knowledge Infrastructure database and China Wanfang database). We calculated survival data, forced vital capacity (FVC) decline, and IPF-related mortality to assess the efficacy of cardiovascular medications in IPF. We also estimated statistical heterogeneity by using I² and Cochran Q tests, and publication bias was evaluated by risk of bias tools ROBINS-I. Results: A total of 12 studies were included in the analysis. The included studies had moderate-to-serious risk of bias. Statin use was associated with a reduction in mortality (hazard ratio (HR), 0.89; 95% CI 0.83-0.97). Meta-analysis did not demonstrate any significant relationship between statin use and the FVC decline (HR, 0.86; 95% CI 0.73-1.02), ACEI/ARB use, and survival data (HR, 0.92; 95% CI 0.73-1.15) as well as anticoagulant use and survival data (HR, 1.16; 95% CI 0.62-2.19). Conclusion: Our study suggested that there is a consistent relationship between statin therapy and survival data in IPF population. However, there is currently insufficient evidence to conclude the effect of ACEI, ARB, and anticoagulant therapy on IPF population especially to the disease-related outcomes in IPF.

Bleeding Complications in Anticoagulated and/or Antiplatelet-Treated Patients at the Dental Office: A Retrospective Study

BACKGROUND

Bleeding complications in patients undergoing antiplatelet and/or anticoagulant therapy have been one of the main concerns in dental practice. Upon the introduction of new antiplatelet and anticoagulant drugs, there is a search for new protocols that respond to a secure treatment. The aim of the present study was to evaluate bleeding complications in anticoagulated and antiplatelet-treated patients after performing simple dental extractions, in a period of 4 years.

MATERIAL AND METHODS

147 clinical records of anticoagulated and/or antiplatelet-treated patients undergoing a simple dental extraction over a period of 4 years (October 2015 to September 2019) were studied. Within the sample, 63 patients were antiplatelet-treated, 83 were anticoagulated, and 1 patient was under both therapies. Within the anticoagulated patients, 70 took classic anticoagulants and 14 new oral anticoagulants (NOACs). Quantitative data were studied with arithmetic mean and standard deviation (SD). The chi-square test was used for the qualitative variables. ANOVA tests were used to compare age and anticoagulated or antiplatelet-treated patients. Statistical significance was determined when p < 0.05.

RESULTS

From the 418 dental extractions performed, five severe bleeding complications took place in three patients (2.11%). From the five events, four were in patients treated with NOACs (1.68%) and one occurred in a patient anticoagulated with acenocoumarol (0.42%; p = 0.003).

CONCLUSIONS

Considering the results of this retrospective clinical study, we can conclude that bleeding complications in anticoagulated and/or antiplatelet-treated patients after tooth extractions were low, with a higher incidence recorded in patients treated with NOACs, followed by classic anticoagulants, and there were no complications in antiplatelet-treated patients.

NOACs: an emerging class of oral anticoagulants-a review article

Background

NOACs, commonly known as novel oral anticoagulants, are the non-vitamin K antagonist oral anticoagulants which are relatively newer in the market. It has displaced vitamin K antagonists, notably warfarin, for many indications. These agents are dabigatran, rivaroxaban, apixaban, and edoxaban.

Main body

The drugs are licenced to prevent stroke and also systemic embolism in patients on treatment for atrial fibrillation and prevent venous thromboembolism. Rivaroxaban and apixaban are approved for prophylaxis of thrombus following surgical hip or knee arthroplasty. The recent surveys reveal that use of NOACs has steeply increased due to its safety profile and convenience to use. Also, the studies have shown that NOACs have lesser bleeding complications and associated mortality in contrast to traditional anticoagulants. The upcoming years are known to be NOACs’ age due to the significant findings in this area.

Conclusion

Therefore, a basic understanding on these drugs is highly recommended to provide a better service to the patients. This article aims to provide quick and brief information on the novel class of drugs. It equips an overview of NOAC and deals with the following areas: (i) pharmacology, (ii) laboratory methods, (iii) peri-operative management, (iv) advantages, (v) challenges, and (vi) future.

Binding of direct oral anticoagulants to the FA1 site of human serum albumin

The anticoagulant therapy is widely used to prevent and treat thromboembolic events. Until the last decade, vitamin K antagonists were the only available oral anticoagulants; recently, direct oral anticoagulants (DOACs) have been developed. Since 55% to 95% of DOACs are bound to plasma proteins, the in silico docking and ligand-binding properties of drugs apixaban, betrixaban, dabigatran, edoxaban, and rivaroxaban and of the prodrug dabigatran etexilate to human serum albumin (HSA), the most abundant plasma protein, have been investigated. DOACs bind to the fatty acid (FA) site 1 (FA1) of ligand-free HSA, whereas they bind to the FA8 and FA9 sites of heme-Fe(III)- and myristic acid-bound HSA. DOACs binding to the FA1 site of ligand-free HSA has been validated by competitive inhibition of heme-Fe(III) recognition. Values of the dissociation equilibrium constant for DOACs binding to the FA1 site (ie, ^calc K_DOAC ) derived from in silico docking simulations (ranging between 1.2 × 10^-8 M and 1.4 × 10^-6 M) agree with those determined experimentally from competitive inhibition of heme-Fe(III) binding (ie, ^exp K_DOAC ; ranging between 2.5 × 10^-7 M and 2.2 × 10^-6 M). In addition, this study highlights the inequivalence of rivaroxaban binding to mammalian serum albumin. Given the HSA concentration in vivo (~7.5 × 10^-4 M), values of K_DOAC here determined indicate that the formation of the HSA:DOACs complexes in the absence and presence of FAs and heme-Fe(III) may occur in vivo. Therefore, HSA appears to be an important determinant for DOACs transport.

Cyclic peptide FXII inhibitor provides safe anticoagulation in a thrombosis model and in artificial lungs

Inhibiting thrombosis without generating bleeding risks is a major challenge in medicine. A promising solution may be the inhibition of coagulation factor XII (FXII), because its knock-out or inhibition in animals reduced thrombosis without causing abnormal bleeding. Herein, we have engineered a macrocyclic peptide inhibitor of activated FXII (FXIIa) with sub-nanomolar activity (K_i = 370 ± 40 pM) and a high stability (t_1/2 > 5 days in plasma), allowing for the preclinical evaluation of a first synthetic FXIIa inhibitor. This 1899 Da molecule, termed FXII900, efficiently blocks FXIIa in mice, rabbits, and pigs. We found that it reduces ferric-chloride-induced experimental thrombosis in mice and suppresses blood coagulation in an extracorporeal membrane oxygenation (ECMO) setting in rabbits, all without increasing the bleeding risk. This shows that FXIIa activity is controllable in vivo with a synthetic inhibitor, and that the inhibitor FXII900 is a promising candidate for safe thromboprotection in acute medical conditions.

Management of antiplatelet or anticoagulant therapy in endoscopy: A review of literature

Endoscopic procedures hold a basal risk of bleeding that depends on the type of procedure and patients’ comorbidities. Moreover, they are often performed in patients taking antiplatelet and anticoagulants agents, increasing the potential risk of intraprocedural and delayed bleeding. Even if the interruption of antithrombotic therapies is undoubtful effective in reducing the risk of bleeding, the thromboembolic risk that follows their suspension should not be underestimated. Therefore, it is fundamental for each endoscopist to be aware of the bleeding risk for every procedure, in order to measure the risk-benefit ratio for each patient. Moreover, knowledge of the proper management of antithrombotic agents before endoscopy, as well as the adequate timing for their resumption is essential.

This review aims to analyze current evidence from literature assessing, for each procedure, the basal risk of bleeding and the risk of bleeding in patients taking antithrombotic therapy, as well as to review the recommendation of American society for gastrointestinal endoscopy, European society of gastrointestinal endoscopy, British society of gastroenterology, Asian pacific association of gastroenterology and Asian pacific society for digestive endoscopy guidelines for the management of antithrombotic agents in urgent and elective endoscopic procedures.

Thromboembolic and bleeding risk of periprocedural bridging anticoagulation: A systematic review and meta-analysis

The risk and benefit of periprocedural heparin bridging is not completely clarified. We aimed to assess the safety and efficacy of bridging anticoagulation prior to invasive procedures or surgery. Heparin bridging was associated with lower risks of thromboembolism and bleeding compared to non‐bridging. PubMed, Ovid and Elsevier, and Cochrane Library (2000‐2016) were searched for English‐language studies. Studies comparing interrupted anticoagulation with or without bridging and continuous oral anticoagulation in patients at moderate‐to‐high thromboembolic risk before invasive procedures were included. Primary outcomes were thromboembolic events and bleeding events. Mantel‐Haenszel method and random‐effects models were used to analyze the pooled risk ratio (RR) and 95% confidence interval (CI) for thromboembolic and bleeding risks. Eighteen studies (six randomized controlled trials and 12 cohort studies) were included (N = 23 364). There was no difference in thromboembolic risk between bridged and non‐bridged patients (RR: 1.26, 95% CI: 0.61‐2.58; RCTs: RR: 0.71, 95% CI: 0.23‐2.24; cohorts: RR: 1.45, 95% CI: 0.63‐3.37). However, bridging anticoagulation was associated with higher risk of overall bleeding (RR: 2.83, 95% CI: 2.00‐4.01; RCTs: RR: 2.24, 95% CI: 0.99‐5.09; cohorts: RR: 3.09, 95% CI: 2.07‐4.62) and major bleeding (RR: 3.00, 95% CI: 1.78‐5.06; RCTs: RR: 2.48, 95% CI: 1.29‐4.76; cohorts: RR: 3.22, 95% CI: 1.65‐6.32). Bridging anticoagulation was associated with increased bleeding risk compared to non‐bridging. Thromboembolism risk was similar between two strategies. Our results do not support routine use of bridging during anticoagulation interruption.

Experiencia de validación de material educativo pacientes anticoagulados en un servicio de consulta externa

La terapia con anticoagulantes está indicada en los procesos trombóticos y requieren un manejo integral para reducir los eventos adversos. Las medidas para el seguimiento incluyen monitorización,  vigilancia y educación continua creando alternativas pedagógicas que facilitan los procesos de recepción y apropiación de la información. Objetivo: validar el material educativo para el paciente anticoagulado asistente al servicio de hematología. Metodología: la experiencia se desarrolló en tres fases: búsqueda bibliográfica, construcción y diseño del material educativo, y validación. Para esta fase se realizaron dos procesos, uno de validación técnica y otro con la comunidad. Resultados: se identificaron 19 documentos, ninguno reportó procesos de validación. Con base en la documentación analizada se consideró que el material más adecuado para la población era una cartilla educativa. Discusión: los materiales educativos para pacientes son una herramienta utilizada  con frecuencia por el sistema de salud, como complemento de la atención que se realiza por fuera de la consulta médica, pero son escasos los procesos de validación rigurosa de este tipo de material en el área de hematología.

A Multidisciplinary Approach on the Perioperative Antithrombotic Management of Patients With Coronary Stents Undergoing Surgery: Surgery After Stenting 2

Perioperative management of antithrombotic therapy in patients treated with coronary stents undergoing surgery remains poorly defined. Importantly, surgery represents a common reason for premature treatment discontinuation, which is associated with an increased risk in mortality and major adverse cardiac events. However, maintaining antithrombotic therapy to minimize the incidence of perioperative ischemic complications may increase the risk of bleeding complications. Although guidelines provide some recommendations with respect to the perioperative management of antithrombotic therapy, these have been largely developed according to the thrombotic risk of the patient and a definition of the hemorrhagic risk specific to each surgical procedure, key to defining the trade-off between ischemia and bleeding, is not provided. These observations underscore the need for a multidisciplinary collaboration among cardiologists, anesthesiologists, hematologists and surgeons to reach this goal. The present document is an update on practical recommendations for standardizing management of antithrombotic therapy management in patients treated with coronary stents (Surgery After Stenting 2) in various types of surgery according to the predicted individual risk of thrombotic complications against the anticipated risk of surgical bleeding complications. Cardiologists defined the thrombotic risk using a "combined ischemic risk" approach, while surgeons classified surgeries according to their inherent hemorrhagic risk. Finally, a multidisciplinary agreement on the most appropriate antithrombotic treatment regimen in the perioperative phase was reached for each surgical procedure.

Direct Oral Anticoagulant Drugs: On the Treatment of Cancer-Related Venous Thromboembolism and their Potential Anti-Neoplastic Effect

Cancer patients develop a hypercoagulable state with a four- to seven-fold higher thromboembolic risk compared to non-cancer patients. Thromboembolic events can precede the diagnosis of cancer, but they more often occur at diagnosis or during treatment. After malignancy itself, they represent the second cause of death. Low molecular weight heparins are the backbone of the treatment of cancer-associated thromboembolism. This treatment paradigm is possibly changing, as direct oral anticoagulants (DOACs) may prove to be an alternative therapeutic option. The currently available DOACs were approved during the first and second decades of the 21st century for various clinical indications. Three molecules (apixaban, edoxaban and rivaroxaban) are targeting the activated factor X and one (dabigatran) is directed against the activated factor II, thrombin. The major trials analyzed the effect of these agents in the general population, with only a small proportion of cancer patients. Two published and several ongoing studies are specifically investigating the use of DOACs in cancer-associated thromboembolism. This article will review the current available literature on the use of DOACs in cancer patients. Furthermore, we will discuss published data suggesting potential anti-cancer actions exerted by non-anticoagulant effects of DOACs. As soon as more prospective data becomes available, DOACs are likely to be considered as a potential new therapeutic option in the armamentarium for patients suffering of cancer-associated thromboembolism.

Phenotyping of CYP 4501A2 Activity by Total Overnight Salivary Caffeine Assessment (TOSCA) in Patients on Warfarin Treatment: A Cross-Sectional Study

Warfarin is an oral anticoagulant, commonly used for primary and secondary prevention of venous and arterial thromboembolic events. The drug is characterized by narrow therapeutic index, widespread individual variability in clinical response, and high rates of adverse events, particularly bleeding complications. For these reasons, a close monitoring of the dosage, using the frequent assessment of coagulation status by means of International Normalized Ratio value, is mandatory. Warfarin is metabolized by hepatic cytochrome P-450. High CYP 450 activity may lead to low drug concentration and requires high warfarin doses to reach efficacy; conversely, low CYP 450 activity is responsible for high drug concentration and needs for low doses to avoid potential toxicity risks. The major isoforms of CYP involved in the metabolism of warfarin sodium are CYP1A2 (for the R-warfarin) and CYP2C9 (for the S-warfarin). The probes for testing CYP1A2 are phenacetin and caffeine while for CYP2C9 tolbutamide. Although S-warfarin has major activity, it was decided to exclude its phenotyping for ethical issues, being mandatory to use a drug (tolbutamide). Instead, it was chosen to test the 1A2 isoform, as the activity of the latter isoform could be investigated by using caffeine contained in the caffeinated beverages. Specifically, a single-point concentration of salivary caffeine (total overnight salivary caffeine assessment [TOSCA]) after an overnight period of the caffeinated beverages abstinence was utilized. In the present study, 75 nonsmoker patients regularly receiving warfarin sodium were enrolled. The results have showed a significant association of the warfarin dose with TOSCA values (coefficient = -0.15, standard error = 0.04, 95% confidence interval = -0.24 to -0.06, t = -3.23, P = .002). In conclusion, the phenotyping of CYP1A2 by TOSCA could be useful, if further proven, to help manage patients on warfarin in order to lessen severe adverse events.

Measurement of rivaroxaban concentrations demonstrates lack of clinical utility of a PT, dPT and APTT test in estimating levels

INTRODUCTION

Rivaroxaban concentrations were measured in 127 inpatient samples using an HPLC-MS/MS assay.

METHODS

We compared this measurement with a calibrated anti-Xa assay and performed PT, aPTT and dilute PT tests to assess the value of clot-based assays in clinical decision-making.

RESULTS

The correlation between the anti-Xa assay and the HPLC-MS/MS at therapeutic concentrations was strong (R²  = 0.98). The PT, RecombiPlasTin 2G, and aPTT, Actin FS, showed a linear dose-response but poor correlation (R²  = 0.32 and 0.44, respectively) and at dilutions of 1 in 150 to 1 in 750 the dilute PT assay also showed poor correlation with rivaroxaban concentrations measured by specific assays. A normal PT or aPTT alone did not identify a likely safe rivaroxaban concentration to allow surgery or invasive procedures, but the combination of normal PT and aPTT identified a group of patients with rivaroxaban levels less than 90 ng/mL. Combined normal PT and aPTT had specificity and sensitivity of 0.97 (95% CI 0.92-0.99) and 0.37 (95% CI 0.1-0.74) for a rivaroxaban concentration < 32 ng/mL.

CONCLUSIONS

The PT and aPTT show poor correlation with rivaroxaban levels measured by calibrated anti-Xa and HPLC-MS/MS assays. A normal combined PT and APTT identified low rivaroxaban levels with high specificity but lacked sensitivity. The dPT assay at several dilutions could not be used to quantify rivaroxaban in clinical samples. The utility of these PT, aPTT and dilute PT assays in a clinical setting is very limited, and results generated must be interpreted with caution.

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.

The perioperative management of new direct oral anticoagulants: a question without answers

New direct oral anticoagulant agents (DOAC) are currently licensed for thromboprophylaxis after hip and knee arthroplasty and for longterm prevention of thromboembolic events in non-valvular atrial fibrillation as well as treatment and secondary prophylaxis of venous thromboembolism. Some other medical indications are emerging. Thus, anaesthesiologists are increasingly likely to encounter patients on these drugs who need elective or emergency surgery. Due to the lack of experience and data, the management of DOAC in the perioperative period is controversial. In this article, we review available information and recommendations regarding the periprocedural management of the currently most clinically developed DOAC, apixaban, dabigatran, and rivaroxaban. We discuss two trends of managing patients on DOAC for elective surgery. The first is stopping the DOAC 1–5 days before surgery (depending on the drug, patient and bleeding risk) without bridging. The second is stopping the DOAC 5 days preoperatively and bridging with low-molecular-weight heparin. The management of patients on DOAC needing emergency surgery is also reviewed. As no data exist for the use of haemostatic products for the reversal of the anticoagulant effect in these cases, rescue treatment recommendations are proposed.

Targeted Thromboelastographic (TEG) Blood Component and Pharmacologic Hemostatic Therapy in Traumatic and Acquired Coagulopathy

Trauma-induced coagulopathy (TIC) is a recently described condition which traditionally has been diagnosed by the common coagulation tests (CCTs) such as prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), platelet count, and fibrinogen levels. The varying sensitivity and specificity of these CCTs have led trauma coagulation researchers and clinicians to use Viscoelastic Tests (VET) such as Thromboelastography (TEG) to provide Targeted Thromboelastographic Hemostatic and Adjunctive Therapy (TTHAT) in a goal directed fashion to those trauma patients in need of hemostatic resuscitation. This review describes the utility of VETs, in particular, TEG, to provide TTHAT in trauma and acquired non-trauma-induced coagulopathy.

Accuracy and consistency of anti-Xa activity measurement for determination of rivaroxaban plasma levels

Essentials Accurate determination of anticoagulant plasma concentration is important in clinical practice. We studied the accuracy and consistency of anti-Xa assays for rivaroxaban in a multicentre study. In a range between 50 and 200 μg L-1 , anti-Xa activity correlated well with plasma concentrations. The clinical value might be limited by overestimation and intra- and inter-individual variation.

SUMMARY

Background Determining the plasma level of direct oral anticoagulants reliably is important in the work-up of complex clinical situations. Objectives To study the accuracy and consistency of anti-Xa assays for rivaroxaban plasma concentration in a prospective, multicenter evaluation study employing different reagents and analytical platforms. Methods Rivaroxaban 20 mg was administered once daily to 20 healthy volunteers and blood samples were taken at peak and trough levels (clinicaltrials.gov NCT01710267). Anti-Xa activity was determined in 10 major laboratories using different reagents and analyzers; corresponding rivaroxaban plasma concentrations were measured by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). Findings Overall Pearson's correlation coefficient of anti-Xa levels and HPLC-MS results was 0.99 for Biophen® Heparin (95% CI, 0.99, 0.99), Biophen® DiXaI (95% CI, 0.99, 0.99) and STA® anti-Xa liquid (95% CI, 0.99, 1.00). Correlation was lower in rivaroxaban concentrations below 50 μg L-1 and above 200 μg L-1 . The overall bias of the Bland-Altman difference plot was 14.7 μg L-1 for Biophen Heparin, 17.9 μg L-1 for Biophen DiXal and 19.0 μg L-1 for STA anti-Xa liquid. Agreement between laboratories was high at peak level but limited at trough level. Conclusions Anti-Xa activity correlated well with rivaroxaban plasma concentrations, especially in a range between 50 and 200 μg L-1 . However, anti-Xa assays systematically overestimated rivaroxaban concentration as compared with HPLC-MS, particularly at higher concentrations. This overestimation, coupled with an apparent interindividual variation, might affect the interpretation of results in some situations.

Hand and wrist surgery without suspending warfarin or oral antiplatelet - systematic review

To assess, through a systematic literature review, whether or not it is necessary to suspend antithrombotic medications (warfarin, aspirin, and clopidogrel) to perform elective wrist and hand surgeries. The search for articles was performed using a combination of keywords in the databases available, without scientific design constraints, being selected series with five or more surgeries; the selected articles were analyzed regarding serious (need for surgical treatment) and mild complications (without surgery). Seven articles were retrieved and analyzed; 410 wrist and hand surgeries were performed in patients on warfarin or aspirin and clopidogrel, with three serious complications (0.7%) and 38 mild (9.2%); 2023 surgeries were performed in patients without use of antithrombotics, with zero serious and 18 (0.8%) minor complications. Patients using warfarin or oral antiplatelet (aspirin, clopidogrel, and aspirin associated with clopidogrel) need not suspend the medication to undergo wrist and hand surgery.

Direct oral anticoagulant considerations in solid organ transplantation: A review

For more than 60 years, warfarin was the only oral anticoagulation agent available for use in the United States. In many recent clinical trials, several direct oral anticoagulants (DOACs) demonstrated similar efficacy with an equal or superior safety profile, with some other notable benefits. The DOACs have lower inter- and intrapatient variability, much shorter half-lives, and less known drug-drug and drug-food interactions as compared to warfarin. Despite these demonstrated benefits, the use of DOACs has not gained uniform acceptance because of lack of supportive data in special patient populations, including recipients of solid organ transplants maintained on immunosuppression. This review describes the properties of several novel DOACs including their pharmacology and mechanisms of action as they relate to use among solid organ transplant recipients. We have particularly focused on (i) dosing in patients with impaired renal and hepatic function; (ii) considerations for drug-drug interactions with immunosuppressive medications; and (iii) management of the anticoagulated patients at the time of unplanned surgery. The risks and benefits of the use of DOACs in solid organ transplant recipients should be carefully evaluated prior to the introduction of these agents in this highly distinct patient population.

Perioperative Management of Anticoagulation-Review of Latest Evidence

Periprocedural anticoagulation bridging is recommended to reduce the risk of thromboembolic events in patients at a higher risk of developing thromboembolism during the perioperative period. The optimal periprocedural anticoagulation strategy has not been established. Unfractionated heparin and low molecular heparin are used in preventing thromboembolism in the special population. Novel oral anticoagulants that directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban) are shown as effective anticoagulants in preventing thromboembolism (venous thromboembolism) in various medical conditions. They have the advantage of having a faster onset, shorter half-lives, easier monitoring, and predicable doses. But there are disadvantages to newer anticoagulants such as the unavailability of definitive reversal agents and lack of data in patients with renal insufficiency. We review the latest evidence on the effects of newer oral anticoagulants in preventing thromboembolism and its bleeding risks.

Periprocedural Management of Non-Vitamin K Oral Anticoagulants in Chronic Kidney Disease: A Review of Existing Heterogeneity and Contemporary Evidence

Non vitamin-K oral anticoagulants (NOAC) have considerably enhanced anticoagulation practice for non-valvular atrial fibrillation with specific advantages of fixed dosing, non-fluctuant therapeutic levels and obviation of therapeutic level monitoring. NOAC pharmacology is remarkable for considerable renal excretion. Heterogeneity in the precise time cut-offs for discontinuation of NOACs prior to elective surgical or percutaneous procedures arise from the non-linear variations of drug excretion with different levels of creatinine clearances as in chronic kidney disease. Multiple authors have suggested cut-offs leading to ambiguity among practicing clinicians. Recent data pertaining to systemic thromboembolism, stroke and major bleeding derived from randomized controlled clinical trials have simplified the periprocedural management of NOACs. This review focusses on heterogeneity in the management of NOACs in patients with CKD in this peculiar scenario and highlights the contemporary evidence to support a unified approach towards perioperative management of NOACs. Multiple antidotes targeted towards binding of specific NOACs have been developed and are in the testing phase, thereby offering immense potential for rapid and complete reversal of NOAC activity in emergent procedures and major bleeding episodes. Targeted research on thromboembolism, stroke and major bleeding following temporary periprocedural interruption of NOACs using multicentric registries could further expand the clinical utility of these agents.

Implications of apixaban for dental treatments

Background

Anticoagulation therapy is used in several conditions to prevent or treat thromboembolism. Recently, new oral anticoagulants have been introduced as alternatives to warfarin and acenocoumarol. In Europe, the European Medicines Agency has approved dabigatran, rivaroxaban and apixaban. Their advantages include: predictable pharmacokinetics, drug interactions and limited food, rapid onset of action and short half-life. However, they lack a specific reversal agent.

Material and Methods

A literature search was conducted through November 2015 for publications in the ISI Web of Knowledge, PubMed, Scopus and Cochrane Library using the keywords “apixaban”, “rivaroxaban”, “dabigatran”, “new oral anticoagulants”, “dental treatment” and “dental implications”. We included studies published in English and Spanish over the last 10 years.

Results

Apixaban has been recently introduced in the daily medical practices for the control of thromboembolism. The number of patients taking apixaban is increasing. Management of patients on anticoagulation therapy requires that dentists can accurately assess the patient prior to dental treatments. It is important for dentists to have a sound understanding of the mechanisms of action and management guidelines for patients taking new oral anticoagulants.

Conclusions

The dentist should consider carefully the management of patients on apixaban. This paper sets out a clinical guidance of dental practitioners treating these patients. There is a need for further clinical studies in order to establish more evidence-based guidelines for dental patients requiring apixaban.

Key words:Apixaban, new oral anticoagulants, dental treatment.

Novel oral anticoagulants for atrial fibrillation

Anticoagulation therapy is effective in preventing primary and secondary thromboembolic events due to atrial fibrillation. Warfarin, which was approved by the United States in 1954, was the only long-term oral anticoagulation therapy till the approval of dabigatran in 2010, and of rivaroxaban and other direct factor Xa inhibitors from 2011, forming a group known as novel oral anticoagulants (NOAC). NOAC have fewer food and drug interactions compared to warfarin; hence, the patient will require fewer clinic visits. However, the short half-life of NOAC means that twice-a-day dosing is needed and there is higher risk of a prothrombotic state when doses are missed. Other disadvantages are the lack of long-term data on NOAC, their high cost and the current lack of locally available antidotes.

Successful use of rivaroxaban in postoperative deep vein thrombosis of the lower limb following instability with warfarin: a case report

Background

Evidence from clinical trials shows rivaroxaban to be effective for the treatment of deep vein thrombosis. Switching to rivaroxaban following failure of indirect anticoagulants in deep vein thrombosis has not been demonstrated in a real-life setting.

Case presentation

A 43-year-old white woman was switched from warfarin to rivaroxaban for the treatment of thrombosis of her right common femoral vein after saphenectomy. The reason for the switch was due to the instability of anti-coagulation therapy with vitamin K antagonists over a period of 3 months during which she did not reach the “therapeutic range” of prothrombin time-international normalized ratio.

The ineffectiveness of the conventional oral anticoagulant was confirmed by persistence of moderate-high values of fibrin D dimers (780 ng/ml) and by residual vein thrombosis at an ultrasound examination. Objectively, her right leg appeared to be still edematous and warm and pain was elicited by deep palpation. Rivaroxaban was administered after warfarin discontinuation (prothrombin time-international normalized ratio = 1.43) at a dosage of 15 mg every 12 hours for 3 weeks, followed by 20 mg once daily for 3 months. After this period, her objective symptoms significantly improved, with reduction of edema of her lower limb and pain relief. Her fibrin D dimer values returned to normal (210 ng/ml). An ultrasound showed recanalization of the obstructed venous segment.

Conclusions

In this case report, a switch to rivaroxaban from warfarin was shown to be effective and safe for the treatment of postoperative deep vein thrombosis, whereas standard oral anticoagulation therapy, which required dose adjustments over a period of 3 months, was not able to stabilize the therapeutic range of prothrombin time-international normalized ratio nor improve our patient’s outcome.

The Active Metabolite of Warfarin (3'-Hydroxywarfarin) and Correlation with INR, Warfarin and Drug Weekly Dosage in Patients under Oral Anticoagulant Therapy: A Pharmacogenetics Study

Objectives

Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3’-hydroxywarfarin, and drug weekly dosage aimed at searching novel alternatives to OAT monitoring. VKORC1/CYP2C9 pharmacogenetics investigation was performed to account for the known influence on warfarin homeostasis.

Methods

133 OAT patients were recruited and assessed for warfarin/3’-hydroxywarfarin serum levels (HPLC), INR, and VKORC1 and CYP2C9 genotypes. A subgroup of 52 patients were monitored in detail (5 consecutive controls; c0-c4) till the target INR was reached. Correlation analyses were performed in both groups

Results

In the whole OAT group both warfarin and 3’-hydroxywarfarin correlate with INR at comparable degree (r² = 0.0388 and 0.0362 respectively). Conversely, warfarin weekly dosage better correlates with warfarin than with 3’-hydroxywarfarin (r² = 0.0975 and r² = 0.0381 respectively), but considering together warfarin plus 3’-hydroxywarfarin the correlation strongly increased (r² = 0.1114; p<0.0001). Interestingly, 3’-hydroxywarfarin reached a strong correlation at c4 respect to warfarin (r² = 0.2157 and r² = 0.0549; p = 0.0005 and p = 0.0944 respectively) seeming less affected by drug adjustments in the subgroup of 52 patients who started OAT. The multivariate analyses aimed at estimating the true contribution of 3’-hydroxywarfarin on INR value ascribed it the unique significant value (p = 0.0021) in spite of warfarin who lost association. The pharmacogenetics studies confirmed that patients carrying the VKORC1 variant-allele required lower warfarin maintenance dosage and that the combination of VKORC1 and CYP2C9 yielded a warfarin responsive index (WRI) inversely related to the number variant alleles

Conclusion

Our results overall suggest that 3’-hydroxywarfarin monitoring could be of great advantage in INR monitoring respect to classical warfarin assessment showing significant contribution also in multivariate analysis. Therefore, additional active metabolites should be recognized and investigated as novel useful indicators.

Oral Anticoagulation in the Elderly: New Oral Anticoagulants-Innovative Solution for an Old Problem?

Direct oral anticoagulants emerge as the most innovative and promising drug toward preventing and treating cardiovascular disease, raising great interest among the scientific community. Numerous studies and meta-analysis generated much data clarifying clinicians' doubts; however, uncertainties remain regarding their use in particular groups such as patients with prosthetic valves, in valvular atrial fibrillation (defined as atrial fibrillation related to mitral rheumatic heart disease or prosthetic heart valves), among the elderly, in paraneoplastic thromboembolism, in pulmonary embolism with hemodynamic compromise, and scarcity of specific antidotes. This review article intends to condense the vast scientific production addressing new oral anticoagulants by focusing on their advantages and disadvantages when used on the elderly.

Prescribing patterns of target-specific oral anticoagulants: an academic hospital perspective

Target-specific oral anticoagulants have been rapidly adopted into clinical practice for stroke prophylaxis and venous thromboembolism treatment, raising concerns about off-label prescribing practices. We conducted a retrospective review of consecutive patients prescribed dabigatran, rivaroxaban or apixaban prior to inpatient hospitalization over an 18-month period to examine the off-label prescribing frequency, contraindications and related complications. Chart review included baseline demographics, hospital admitting service, outpatient prescribing service, renal function, therapeutic indication, echocardiographic findings, contraindications, major bleeding events and vital status. We identified 160 patients who received a target-specific oral anticoagulant prior to hospitalization. Over half (53.1%) of the patients received rivaroxaban, 43.7% received dabigatran and 3.1% received apixaban. Atrial fibrillation (68.1%) and venous thromboembolism treatment (25.6%) were the most common indications. Ninety percent of patients had a U.S. Foods and Drugs Administration (FDA)-approved indication for therapy. Major bleeding events occurred in 4.4% of patients. Cardiology was the most common prescribing and admitting service (43.8 and 31.3%), and more frequently adhered to FDA-approved indications (97 vs. 84%, P = 0.01). There were no significant differences between prescribing services regarding major contraindications (P = 0.14) and major bleeding events (P = 0.77). Off-label prescription rates for target-specific oral anticoagulants were infrequent and not associated with increased adverse events.

A critical balance: managing coagulation in patients with glioma

Cancer-associated thrombosis, including both arterial and venous thromboembolism (VTE), is a significant source of morbidity and mortality in patients with glioma. This risk is highest in the immediate postoperative period and is increased by chemotherapy, radiation, and corticosteroids. Systemic anticoagulation with low molecular weight heparin is the treatment of choice in both the therapeutic and prophylactic settings. However, these patients are also at risk of intracranial hemorrhage, a potentially catastrophic complication of anticoagulation, and this risk must be carefully balanced against the risk of VTE. In this review we outline the incidence, pathophysiology and management of thrombosis in patients with glioma, with a focus on clinical considerations including perioperative management, chemotherapy-induced thrombocytopenia, and end-of-life management.

North American Thrombosis Forum, AF Action Initiative Consensus Document

The North American Thrombosis Forum Atrial Fibrillation Action Initiative consensus document is a comprehensive yet practical briefing document focusing on stroke and bleeding risk assessment in patients with atrial fibrillation, as well as recommendations regarding anticoagulation options and management. Despite the breadth of clinical trial data and guideline recommendation updates, many clinicians continue to struggle to synthesize the disparate information available. This problem slows the uptake and utilization of updated risk prediction tools and adoption of new oral anticoagulants. This document serves as a practical and educational reference for the entire medical community involved in the care of patients with atrial fibrillation.

New Direct Oral Anticoagulants (DOAC) and Their Use Today

The ideal anticoagulant is oral, has a wide therapeutic range, predictable pharmacokinetics and pharmacodynamics, a rapid onset of action, an available antidote, minimal side effects and minimal interactions with other drugs or food. With the development of the novel direct oral anticoagulants (DOAC), we now have an alternative to the traditional vitamin K antagonists (VKA) for the prevention and treatment of thrombosis. DOACs have limited monitoring requirements and very predictable pharmacokinetic profiles. They were shown to be non-inferior or superior to VKA in the prophylaxis or treatment of thromboembolic events. Particularly in terms of safety they were associated with less major bleeding, including intracranial bleeding, thus providing a superior benefit for the prevention of stroke in patients with atrial fibrillation. Despite these advantages, there are remaining limitations with DOACs: their dependence on renal and hepatic function for clearance and the lack of an approved reversal agent, whereas such antidotes are successively being made available. DOACs do not need regular monitoring to assess the treatment effect but, on the other hand, they interact with other drugs and interfere with functional coagulation assays. From a practical point of view, the properties of oral administration, simple dosing without monitoring, a short half-life allowing for the possibility of uncomplicated switching or bridging, and proven safety overwhelm the disadvantages, making them an attractive option for short- or long-term anticoagulation.

Strategy of continued vs interrupted novel oral anticoagulant at time of device surgery in patients with moderate to high risk of arterial thromboembolic events: The BRUISE CONTROL-2 trial

BACKGROUND

Patients who require perioperative anticoagulation during cardiac implantable electronic device surgery are at increased risk for bleeding complications. The BRUISE CONTROL trial demonstrated that continuing warfarin was safer than heparin bridging, reducing the incidence of clinically significant pocket hematoma. Novel oral anticoagulants are being increasingly prescribed in place of warfarin. The best perioperative management of these new anticoagulants is unknown.

METHODS/DESIGN

A randomized controlled trial to investigate whether a strategy of continued vs interrupted novel oral anticoagulant (dabigatran, rivaroxaban, or apixaban) at the time of device surgery, in patients with moderate to high risk of arterial thromboembolic events, reduces the incidence of clinically significant hematoma (defined as a hematoma requiring reoperation and/or resulting in prolongation of hospitalization, and/or requiring interruption of anticoagulation). The secondary outcomes include components of the primary outcome, composite of all other major perioperative bleeding events, thromboembolic events, all-cause mortality, cost-effectiveness, patient quality of life, perioperative pain, and satisfaction. Planned analyses include descriptive statistics of all baseline variables. For the primary outcome, interrupted vs continued novel oral anticoagulant arms will be compared using the χ(2) test. If any clinically significant differences are identified, a logistic regression analysis will be conducted. Quality of life will be assessed using EuroQol-5D, and perioperative pain using a visual analog scale.

DISCUSSION

BRUISE CONTROL-2 is a randomized trial evaluating the best strategy to manage novel oral anticoagulants at the time of device surgery. We hypothesize that device surgery can be performed safely without interruption of these medications.

Individualized approaches to thromboprophylaxis in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide. The prevalence of AF in persons older than 55 years is at least 33.5 million globally and is predicted to more than double in the next half-century. Anticoagulation, heart rate control, and heart rhythm control comprise the 3 main treatment strategies in AF. Anticoagulation is aimed at preventing debilitating stroke, systemic embolism, and associated mortality. Historically, anticoagulation in AF was achieved with a vitamin K antagonist such as warfarin, which is supported by evidence demonstrating reduced incident stroke and all-cause mortality. However, warfarin has unpredictable pharmacokinetics with many drug-drug interactions that require regular monitoring to ensure patients remain in the therapeutic anticoagulant range. Non-vitamin K antagonist oral anticoagulants including dabigatran, rivaroxaban, apixaban, and edoxaban provide a possible solution to these issues with their more predictable pharmacokinetics, rapid onset of action, and greater specificity. Results from large randomized, controlled trials indicate that these agents are at least noninferior to warfarin in prevention of stroke. These trials also demonstrate a consistently lower incidence of intracranial hemorrhage, almost always all life-threatening bleeds, and many forms of major bleeds with the possible exception of gastrointestinal and some other forms of mucosal bleeding, compared with warfarin. Patients with AF are a heterogeneous population with diverse risk of stroke and bleeding, and different subgroups respond differently to anticoagulation. Important clinical questions have arisen regarding optimal anticoagulation drug selection in distinct populations such as those with renal impairment, older age, coronary artery disease, and heart failure as well as those at particularly high risk for bleeding or thromboembolism. In this review, treatment strategies in AF management are discussed in the context of different individual subgroups of patients.

Endoscopy in patients on antiplatelet or anticoagulant therapy, including direct oral anticoagulants: British Society of Gastroenterology (BSG) and European Society of Gastrointestinal Endoscopy (ESGE) guidelines

The risk of endoscopy in patients on antithrombotics depends on the risks of procedural haemorrhage versus thrombosis due to discontinuation of therapy. P2Y12 RECEPTOR ANTAGONISTS CLOPIDOGREL, PRASUGREL, TICAGRELOR: For low-risk endoscopic procedures we recommend continuing P2Y12 receptor antagonists as single or dual antiplatelet therapy (low quality evidence, strong recommendation); For high-risk endoscopic procedures in patients at low thrombotic risk, we recommend discontinuing P2Y12 receptor antagonists five days before the procedure (moderate quality evidence, strong recommendation). In patients on dual antiplatelet therapy, we suggest continuing aspirin (low quality evidence, weak recommendation). For high-risk endoscopic procedures in patients at high thrombotic risk, we recommend continuing aspirin and liaising with a cardiologist about the risk/benefit of discontinuation of P2Y12 receptor antagonists (high quality evidence, strong recommendation).

WARFARIN

The advice for warfarin is fundamentally unchanged from British Society of Gastroenterology (BSG) 2008 guidance.

DIRECT ORAL ANTICOAGULANTS DOAC

For low-risk endoscopic procedures we suggest omitting the morning dose of DOAC on the day of the procedure (very low quality evidence, weak recommendation); For high-risk endoscopic procedures, we recommend that the last dose of DOAC be taken ≥48 h before the procedure (very low quality evidence, strong recommendation). For patients on dabigatran with CrCl (or estimated glomerular filtration rate, eGFR) of 30-50 mL/min we recommend that the last dose of DOAC be taken 72 h before the procedure (very low quality evidence, strong recommendation). In any patient with rapidly deteriorating renal function a haematologist should be consulted (low quality evidence, strong recommendation).

Management of Venous Thromboembolism: Recent Advances in Oral Anticoagulation Therapy

OBJECTIVE

To review clinical data on direct oral anticoagulants (DOACs) used in the acute treatment of venous thromboembolism (VTE) as well as practical considerations when using these products.

DATA SOURCES

Searches of PubMed and Google Scholar for VTE, deep vein thrombosis, pulmonary embolism, and relevant drug international nonproprietary names were conducted. Additional online searches were conducted for prescribing information.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles on dabigatran, rivaroxaban, apixaban, and edoxaban for the management of VTE compared with oral vitamin K antagonists (VKAs; published between 1966 and December 2015) were reviewed and summarized, together with information on dosing, pharmacokinetics/pharmacodynamics, and drug-drug interactions.

DATA SYNTHESIS

The DOACs have the potential to circumvent many of the disadvantages of VKAs. At a minimum, they greatly increase the available therapeutic options, thus providing a greater opportunity for clinicians to select a management option that best fits the needs of individual patients. Despite the significant advance that DOACs represent, they are not without risk and require careful consideration of a number of clinical issues to optimize safety and efficacy.

CONCLUSIONS

The emergence of DOACs for the management of thromboembolic disorders represents a paradigm shift from oral VKAs. The DOACs provide similar efficacy and improved safety in selected patients as compared with VKAs. Clinicians treating VTE need to be familiar with the intricacies involved in using these agents, including the appropriate dose selection for the relevant indication, avoidance of drug-drug and drug-disease interactions, and consideration of dose adjustments in specific clinical situations, such as organ dysfunction.

Switching from rivaroxaban to warfarin: an open label pharmacodynamic study in healthy subjects

Aims

The primary objective was to explore the pharmacodynamic changes during transition from rivaroxaban to warfarin in healthy subjects. Safety, tolerability and pharmacokinetics were assessed as secondary objectives.

Methods

An open label, non-randomized, sequential two period study. In treatment period 1 (TP1), subjects received rivaroxaban 20 mg once daily (5 days), followed by co-administration with a warfarin loading dose regimen of 5 or 10 mg (for the 10 mg regimen, the dose could be uptitrated to attain target international normalized ratio [INR] ≥2.0) once daily (2–4 days). When trough INR values ≥2.0 were attained, rivaroxaban was discontinued and warfarin treatment continued as monotherapy (INR 2.0–3.0). During treatment period 2, subjects received the same warfarin regimen as in TP1, but without rivaroxaban.

Results

During co-administration, maximum INR and prothrombin time (PT) values were higher than with rivaroxaban or warfarin monotherapy. The mean maximum effect (E_max) for INR after co-administration was 2.79–4.15 (mean PT E_max 41.0–62.7 s), compared with 1.41–1.74 (mean PT E_max 20.1–25.2 s) for warfarin alone. However, rivaroxaban had the smallest effect on INR at trough rivaroxaban concentrations. Neither rivaroxaban nor warfarin significantly affected maximum plasma concentrations of the other drug.

Conclusions

The combined pharmacodynamic effects during co-administration of rivaroxaban and warfarin were greater than additive, but the pharmacokinetics of both drugs were unaffected. Co-administration was well tolerated. When transitioning from rivaroxaban to warfarin, INR monitoring during co-administration should be performed at the trough rivaroxaban concentration to minimize the effect of rivaroxaban on INR.

Direct oral anticoagulants: New drugs with practical problems. How can nurses help prevent patient harm?

The safe use of anticoagulants requires a delicate balance between the risk of bleeding and the risk of thrombosis, particularly in drug-sensitive patients, such as older people. Recently-marketed "direct oral anticoagulants" are now being increasingly prescribed and administered in the hospital setting. Direct oral anticoagulants have pharmacological properties that are often unpredictable, and inter-patient variability in drug response is high. Therefore, people often require meticulous review and planning to ensure they receive optimal dosing and monitoring. The multidisciplinary medication management of those receiving these drugs needs to be effectively coordinated to reduce the risk of patient harm. All clinical staff, including nurses, doctors, and pharmacists, should be competent in the pharmacology of these drugs, and know which people require individualized care plans. In this study, we introduced important concepts via the use of case studies developed from commonly-seen scenarios at our quaternary hospital. In particular, the important role of nurses in ensuring patient safety in the periprocedural setting is highlighted.

Beyond warfarin: The advent of new oral anticoagulants

New oral anticoagulants (NOAC) are the latest addition to anticoagulant armamentarium. Unlike traditional anti-coagulants like warfarin, lab monitoring and management of bleeding complications secondary to these agents is different. As more and more patients are being switched to these drugs, interventional radiologists in particular will benefit from a clinical review of NOAC.

Prothrombin G20210A Mutation in a 53-Year-Old Male Patient with Deep Vein Thrombosis

PATIENT

A 53-year-old man, ethnicity unknown.

CHIEF COMPLAINT

Leg swelling and pain.

HISTORY OF PRESENT ILLNESS

The patient has a history of atrial fibrillation that had been treated with 3 separate cardiac ablations, most recently in the year 2014. According to the patient, the symptoms had begun the day after his most recent cardiac ablation on June 27, 2014. The catheter for the procedure was inserted via the right femoral vein. The patient had returned to work, where he sits for an average of 8 hours per day, but his pain became unbearable, so he went to the emergency department on July 3, 2014.

PREVIOUS MEDICAL HISTORY

In 2013, he was evaluated for a possible stroke. He reported consuming 1 to 2 alcoholic drinks per month, not using tobacco, and not being currently sexually active. He has no history of excessive bleeding or bruising.

PREVIOUS SURGICAL HISTORY

The patient underwent an operation for an unruptured aneurysm in 2011; ablation for atrial fibrillation in 2006, 2009, and 2014; gastric bypass in 2006; left knee arthroscopy in 2010; and rotator cuff repair in 2013.

FAMILY HISTORY

The patient's sister had died of a pulmonary embolism (age at time of death unknown). His father had died of a stroke at age 49 years. His mother, who is still living, has a history of intracranial aneurysms.

PHYSICAL EXAMINATION RESULTS

The patient was alert and oriented; he cooperated with medical staff. His vital signs were normal, and all body systems were functioning normally. A large ecchymosis extended from his groin to his knee.

PRINCIPAL LABORATORY FINDINGS

See Tables 1-5.

Venous thromboembolism in Latin America: a review and guide to diagnosis and treatment for primary care

There are various region-specific challenges to the diagnosis and effective treatment of venous thromboembolism in Latin America. Clear guidance for physicians and patient education could improve adherence to existing guidelines. This review examines available information on the burden of pulmonary embolism and deep vein thrombosis in Latin America and the regional issues surrounding the diagnosis and treatment of pulmonary embolism and deep vein thrombosis. Potential barriers to appropriate care, as well as treatment options and limitations on their use, are discussed. Finally, an algorithmic approach to the diagnosis and treatment of venous thromboembolism in ambulatory patients is proposed and care pathways for patients with pulmonary embolism and deep vein thrombosis are outlined for primary care providers in Latin America.