Eficácia e segurança de anticoagulantes orais diretos comparados à anticoagulação tradicional com heparina e varfarina para tratamento de tromboembolismo pulmonar e trombose venosa profunda / Effectiveness and safety of direct oral anticoagulants compared to traditional anticoagulation with heparin and varfarine to treat pulmonary thromboembolism and deep venous thrombosis

Tecnologia: Inibidores Diretos do Fator Xa (IDFXa) ­ Rivaroxabana, Apixabana, Edoxabana ­ e Inibidores Diretos da Trombina (IDT) ­ Dabigatrana ­ todos são anticoagulantes orais diretos (DOAC). Indicação: tratamento e prevenção de fenômenos tromboembólicos. Pergunta: Para tratamento de tromboembolismo pulmonar (TEP) e trombose venosa profunda (TVP), os DOAC são mais eficazes e seguros que a anticoagulação tradicional com heparina e varfarina? Métodos: Levantamento bibliográfico na base de dados Pubmed seguindo estratégias de buscas predefinidas. Avaliação da qualidade metodológica das revisões sistemáticas com a ferramenta Assessing the Methodological Quality of Systematic Reviews (AMSTAR). Resultados: Foram selecionadas e incluídas 4 revisões sistemáticas. Conclusão: Na maioria dos estudos incluídos, os DOAC demonstraram eficácia e segurança similar à anticoagulação tradicional com heparina e varfarina para tratamento de TEP e TVP. Em um estudo, o risco de TVP recorrente foi menor no tratamento de IDFXa (por menos 3 meses de tratamento) e de episódios de sangramento maior foi menor no tratamento de IDT e IDFXa (por mais 3 meses de tratamento)

Technology: Direct Factor Xa Inhibitors (DFXaI) - Rivaroxaban, Apixaban, Edoxaban ­ and Direct Thrombin Inhibitors (DTI) - Dabigatran - all are direct oral anticoagulants (DOAC). Indication: treatment and prevention of thromboembolic phenomena. Question: For treatment of pulmonary thromboembolism (PTE) and deep vein thrombosis (DVT), are DOACs more effective and safer than traditional anticoagulation with heparin and warfarin? Methods: Bibliographic survey in the Pubmed database following predefined search strategies. Evaluation of the methodological quality of systematic reviews with the tool Assessing the Methodological Quality of Systematic Reviews (AMSTAR). Results: 4 systematic reviews were selected and included. Conclusion: In most of the included studies, DOAC demonstrated similar efficacy and safety to traditional anticoagulation with heparina and warfarin for the treatment of PTE and DVT. In one study, the risk of recurrent DVT was lower in the treatment of DFXaI (for at least 3 months of treatment) and of major bleeding episodes was lower in the treatment of DTI and DFXaI (for another 3 months of treatment)

Manejo de hemorragia asociada a anticoagulantes orales directos: estado actual de las estrategias de reversión / Management of bleeding associated with direct oral anticoagulants: update on reversal strategies

Direct oral anticoagulants (DOACs), including the direct thrombin inhibitor dabigatran and the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban have at least comparable efficacy as vitamin K antagonists along with a better safety profile, reflected by a lower incidence of intracranial hemorrhage. Specific reversal agents have been developed in recent years. Namely, idarucizumab, a specific antidote for dabigatran, is currently approved in most countries. Andexanet, which reverses factor Xa inhibitors, has been recently approved by the FDA, and ciraparantag, a universal antidote targeted to reverse all DOACs, is still under investigation. In this review we provide an update on the pharmacology of DOACs, the risk of hemorrhagic complications associated with their use, the measurement of their anticoagulant effect and the reversal strategies in case of DOAC-associated bleeding.

The effect of hirudin on antagonisting thrombin induced apoptosis of human microvascular endothelial cells

Abstract Purpose: To investigate whether hirudin exerts its antithrombin action to decrease the ratio of Human Microvascular Endothelial Cells (HMVECs) apoptosis. Methods: Human microvascular endothelial cells (HMVECs) cultured in the third and fifth generations were used. HMVECs were divided into normal group, thrombin group (T group), natrual hirudin group (H group), thrombin + natrual hirudin group (T + H group), AG490 group, thrombin + AG490 group (T + AG490 group), natrual hirudin + AG490 group (H + AG490 group), thrombin + natural hirudin + AG490 (T + H + AG490 group).Apart from the normal group, the other groups were exposed to the relevant drugs for 24 hours.HMVEC apoptosis was assessed by flow cytometric and double Immunofluorescence of phosphorylation of JAK (P-JAK2) and TUNEL assay. Results: Compared with the normal group, in thrombin group the HMVECs apoptosis rate were significantly increased (P<0.05).The results indicated that the index of apoptosis and the apoptosis rate were improved in cultures treated by natural hirudin (T + H group), relative to cultures with thrombin only (T group). We found that the index of apoptosis and the apoptosis rate in the AG490 + thrombin group were higher than that in the hirudin + thrombin group (P<0.05). Double Immunofluorescence of p-JAK2 and TUNEL assays showed that cells were double positive for P-JAK2 uptake and TUNEL detection liquid binding. Conclusion: The natural hirudin and JAK2/STATs signal inhibitor AG490 could block the effects of thrombin. Natural hirudin could attenuate HMVECs apoptosis via antagonizing thrombin and it is suggested that this effect may occur by blocking the JAK2/STATs signaling pathway and this signaling pathways appears to be not the only pathway.

Use of direct oral anticoagulants for chronic thromboembolic pulmonary hypertension

OBJECTIVES: Chronic thromboembolic pulmonary hypertension is one of the most prevalent forms of pulmonary hypertension and is a major complication of acute pulmonary embolism. One mainstay of chronic thromboembolic pulmonary hypertension treatment is lifelong anticoagulation. The recent advent of direct oral anticoagulants for acute pulmonary embolism treatment has provided a viable and effective alternative for treating this condition. However, little is known about the efficacy of this new class of drugs for treating chronic thromboembolic pulmonary hypertension. We aimed to evaluate the safety and efficacy of direct oral anticoagulants in the treatment of chronic thromboembolic pulmonary hypertension. METHODS: A cohort of chronic thromboembolic pulmonary hypertension patients who initiated treatment with direct oral anticoagulants between June 2015 and November 2016 were enrolled in this study. RESULTS: Sixteen patients used rivaroxaban, three used dabigatran and one used apixaban for a mean follow-up of 20.9 months. The mean age was 51 years, and eighteen patients were classified as functional class II/III. Eight patients underwent a pulmonary endarterectomy and exhibited clinical, hemodynamic and functional improvement and currently continue to use direct oral anticoagulants. No episode of venous thromboembolism recurrence was identified during the follow-up period, but there was one episode of major bleeding after a traumatic fall. CONCLUSIONS: Although direct oral anticoagulants appear to be a safe and effective alternative for treating chronic thromboembolic pulmonary hypertension, larger studies are needed to support their routine use.

Comparison of Rhythm and Rate Control Strategies for Stroke Occurrence in a Prospective Cohort of Atrial Fibrillation Patients

PURPOSE: Comparisons of rhythm and rate control strategies for stroke prevention in patients with atrial fibrillation (AF) are still inconclusive. We compared differences in clinical outcomes between the rhythm and rate control strategies. MATERIALS AND METHODS: The COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF) registry prospectively enrolled 6000 patients who were treated for AF using real-world guideline adherence at multiple referral centers. In total, 2508 (41.8%) patients were clinically followed up for over six months. Of these, 1134 (45.2 %) patients treated by rhythm control and 1374 (54.8 %) patients treated by rate control were analyzed for clinical outcomes, including stroke and cardiovascular outcomes. RESULTS: Among all patients (age, 68±10 years; male, 62.4%), those treated with the rhythm control strategy were significantly younger, had more symptomatic paroxysmal AF, and a shorter AF duration, and were less likely to have diabetes, renal dysfunction, and heart failure, compared to those treated with the rate control strategy (CHA₂DS₂-VASc score 2.4±1.5 vs. 3.1±1.7, p < 0.001). Even though oral anticoagulation was similarly prescribed in both groups, occurrence of stroke was less likely to occur in the rhythm control strategy group (0.0% vs. 0.7%, p=0.015). Multivariate Cox hazard regression showed that only age, especially more than 75 years old, were significantly correlated with the occurrence of stroke, regardless of the strategy used for treatment. CONCLUSION: In this prospective AF cohort, compared with the rate control strategy, the rhythm control strategy was associated with fewer cardiovascular events and strokes in a short-term period.

Nuevos anticoagulantes orales: actualización / New oral anticoagulants: a review

Resumen: Los anticoagulantes orales clásicos del tipo cumarinas han estado disponibles para uso clínico por más de medio siglo. Tienen gran eficacia para tratar o prevenir trombosis y tromboembolias, y son drogas cuyo uso ha aumentado con el mejor conocimiento clínico, el aumento de los factores de riesgo y el envejecimiento de la población. Entre sus desventajas se incluyen la alta variabilidad de su efecto en cada sujeto y entre individuos, la influencia del nivel de ingesta de vitamina K, la necesidad de control periódico del nivel de anticoagulación, su interacción con múltiples drogas. Si bien, el rango terapéutico está estandarizado, es estrecho, haciendo que el tiempo en rango terapéutico sea de ≈ 60%. Por estas limitaciones, se han creado nuevos anticoagulantes orales (NACOs), siendo progresivamente aprobados para uso clínico por agencias internacionales. Genéricamente, son de 2 tipos: inhibidores selectivos de trombina (dabigatrán) o de FXa (rivaroxabán, apixabán, edoxabán y betrixabán). Los NACOs se caracterizan por su dosificación una o dos veces al día, rapidez de acción, corta vida media en la circulación, predictibilidad de su efecto, dosis preestablecidas, sin necesidad de control periódico y con escasa o nula interacción con otras drogas. Estas ventajas no se han traducido en la mayoría de los ensayos en un superior efecto antitrombótico o menor riesgo de sangrado, y en su mayoría (salvo dabigatrán) carecen de antídoto específico demostrado.

Abstracts: Vitamin K inhibitors, coumarins, have been used for more than 50 years with no dispute by other drugs. Coumarins have demonstrated great efficacy in the treatment and prophylaxis of thrombotic and thromboembolic disorders, and their use has increased progressively with the advance of clinical knowledge as well as the increase of risk factors and aging of the population. Limitations of coumarins include great variability intra and inter-individuals, the influence of foods rich in vitamin K, the need for periodical assessment of the anticoagulant level and drug interactions. The therapeutic range is standardized using the INR (International Normalized Ratio). However, the therapeutic window is narrow, with frequent periods of either over or under-dosing, with the concomitant increase of bleeding and thrombotic risks, respectively. Long-term accredited anticoagulant clinics and clinical trials report that, at best, only ≈60% of time in treatment the patients are within the therapeutic range. These limitations have created the need for new oral anticoagulants (NOACs), and several of them have been approved for clinical use by international agencies after exhaustive and specific clinical trials. Generically, NACOs are belong in two types: selective inhibitors of thrombin (dabigatran) or FXa (rivaroxaban, apixaban, edoxaban and betrixaban). NOACs are prescribed once or twice daily, the onset of action is very fast, have a low T1/2 in the circulation, their effects are highly predictable, doses are pre-established, do not need laboratory control and have a low rate of interaction with other drugs. Despite these advantages most clinical trials have shown NOACs to be not inferior with respect to coumarin. However, NOACs have no clear advantages over warfarin in antithrombotic effect or bleeding reduction. Furthermore, most of them (except dabigatran) have no specific antidotes yet.

Características basales, manejo de terapias antitrombóticas y pronóstico de pacientes chilenos con FA no valvular. Lecciones del Registro GARFIELD AF en Chile / Features, management and prognosis of Chilean patients with non valvular atrial fibrillation: GARFIELD AF registry

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with high rates of death, ischemic stroke and systemic embolism (SE). There is scarce information about clinical characteristics and use of anti-thrombotic therapies in Chilean patients with non-valvular AF. Aim: To describe the characteristics and 1-year outcomes of patients with recently diagnosed AF recruited in Chile into the prospective global GARFIELD-AF registry. Material and Methods: Between 2011-2016, we prospectively registered information of 971 patients recruited at 15 centers, 85% of them from the public system and 15% from the private sector. Demographics, clinical characteristics and use of antithrombotic therapies were recorded for all patients. Adverse clinical outcomes were analyzed in 711 patients with 1-year follow-up. Results: The mean age was 71.5 years (66-79), 50% were men. Mean CHAD2S2 Vasc and HAS BLED scores for stroke risk were 3.3 (2.0-4.0) and 1.5 (1.0-2.0) respectively. Oral anticoagulants were prescribed in 82% of patients. Seventy percent received Vitamin K antagonists, 10% novel direct anticoagulants or antiplatelet therapy and only 8% did not receive any antithrombotic therapy. Mean time in optimal therapeutic range (an international normalized ratio of 2 to 3), was achieved in only 40.7% (23.0-54.8) of patients receiving Vitamin K antagonists. One year rates of death, stroke/systemic embolism and bleeding were 4.75 (3.36-6.71), 2.40 (1.47-3.92) and 1.64% (0.91-2.97) per 100 person-years. Ischemic stroke occurred in 1.8% and hemorrhagic stroke in 0.8% of patients at 1-year of follow up. Conclusions: Although the use of vitamin K antagonists at baseline was high, the mean time in optimal therapeutic range was low. Mortality and stroke rates are higher than those reported in other contemporary registries.

Función renal y nivel plasmático de dabigatrán en el valle, medido por un ensayo de trombina diluida / Renal function and plasma dabigatran level measured at trough by diluted thrombin time assay

El dabigatrán etexilato (inhibidor directo de trombina) es eficaz en la prevención tromboembólica en pacientes con fibrilación auricular. No requiere control rutinario de laboratorio, pero dada su eliminación renal, sería importante medirlo ante el deterioro de la función renal. Los objetivos del trabajo fueron verificar la calidad analítica del ensayo tiempo de trombina diluido para medición de la concentración plasmática (cc) de dabigatrán, correlacionar las cc con las pruebas básicas de coagulación tiempo de protrombina (TP) y tiempo de tromboplastina parcial activada (APTT) y evaluarlas de acuerdo al clearance de creatinina (CLCr). Se utilizaron muestras de plasma de 40 pacientes que recibían dabigatrán 150 (n = 19) o 110 (n = 21) mg/12 horas, colectadas 10-14 horas después de la última toma. Los ensayos de trombina diluida HemosIL DTI para la medición de dabigatrán, TP y APTT (IL), fueron realizados en coagulómetros fotoópticos ACL TOP 300 y 500 (IL). El DTI presentó coeficiente de variación intraensayo < 5.4% e interensayo < 6.0%, rango de linealidad 0-493 ng/ml; cc medidas en pacientes: mediana 83 (4-945) ng/ml. Individuos con CLCr en tercil inferior (< 46.1 ml/min) presentaron cc significativamente más elevadas, 308 (49-945), que los de tercilos medio, 72 (12-190), y superior, 60 (4-118) ng/ml. Las correlaciones cc vs. APTT o TP fueron moderadas, r2 = 0.59, -0.66, p < 0.0001, respectivamente. La prueba ensayada permitió cuantificar el nivel de dabigatrán plasmático tanto en pacientes con función renal normal como deteriorada, representando una herramienta útil en situaciones clínicas como deterioro de la función renal, pre cirugía o emergencias.

Dabigatran etexilate (direct thrombin inhibitor) is effective in preventing embolic stroke in patients with atrial fibrillation. It does not require laboratory control, but given the high renal elimination, its measurement in plasma is important in renal failure. The objectives of the study were to verify the analytical quality of the diluted thrombin time assay for measurement of dabigatran plasma concentration (cc), correlate cc with classic coagulation assays, prothrombin time (PT) and activated partial thromboplastin time (APTT), and evaluate them according to the creatinine clearance (CLCr). Forty plasma samples of patients (34 consecutive and 6 suspected of drug accumulation) receiving dabigatran at 150 (n = 19) or 110 (n = 21) mg/12 hours were collected. Blood samples were drawn at 10-14 hours of the last intake. Dabigatran concentration was determined by diluted thrombin time (HemosIl DTI, Instrumentation Laboratory (IL). PT and APTT (IL) were performed on two fotooptical coagulometers, ACL TOP 300 and 500 (IL). DTI presented intra-assay coefficient of variation < 5.4% and inter-assay < 6%, linearity range 0-493 ng/ml. Patients´ cc: median 83 (4-945) ng/ml. Individuals with CLCr in the lowest tertile (22.6-46.1 ml/min) showed significantly higher median cc: 308 (49-945), compared to the average 72 (12-190) and highest tertile, 60 (4-118) ng/ml. Correlation between cc and APTT or PT were moderate, r2 = 0.59 and -0.66, p < 0.0001, respectively. DTI test allowed us to quantify plasma dabigatran levels, both in patients with normal or altered renal function, representing a useful tool in clinical situations such as renal failure, pre surgery or emergencies.

Trombocitopenia inducida por heparina: Nuevas opciones terapéuticas / Heparin-induced thrombocytopenia. New therapeutical options

La trombocitopenia inducida por heparina (TIH) es una reacción adversa inmunológica mediada por la formación de anticuerpos contra el complejo heparina-factor plaquetario 4 (FP4), caracterizada por la presencia de trombocitopenia y la asociación paradojal de trombosis arterial o venosa. Es una complicación poco frecuente pero grave del uso de cualquier tipo de heparina. En tratados con procedimientos cardiovasculares como intervención coronaria percutánea y cirugía de revascularización cardiaca, la prevalencia de anticuerpos es significativamente mayor que en otros escenarios clínicos. El reconocimiento de las características clínicas y de laboratorio permite la suspensión inmediata de la heparina y la instauración de tratamiento anticoagulante alternativo, para evitar la progresión y formación de nuevos trombos y sus complicaciones. En la presente revisión se resumen las diferentes alternativas terapéuticas para la TIH, en particular los anticoagulantes orales directos (DOACS) como el dabigatran, rivaroxaban y apixaban que pueden proporcionar una nueva opción para el tratamiento de TIH.

Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse reaction due to antibodies to a multimolecular complex of heparin and platelet factor 4 (PF4) characterized by moderate thrombocytopenia and paradoxical arterial or venous thrombosis. It is a relatively infrequent complication related to the administration of any type of heparin. In patients undergoing percutaneous coronary revascularization or coronary artery by-pass graft the prevalence of HIT is higher than in other clinical settings. Recognizing clinical and laboratory features of HIT allow immediate discontinuation of heparin and the use of alternative anticoagulants to avoid serious thrombotic complications. In this review, we summarize different therapeutic options for the treatment of HIT with special emphasis on direct oral anticoagulants (DOACS) such as dabigatran, rivaroxaban and apixaban. DOACS might represent a therapeutic alternative for HIT treatment.

A Practical Guide to Ordering and Interpreting Coagulation Tests for Patients on Direct Oral Anticoagulants in Singapore

<p><b>INTRODUCTION</b>Direct oral anticoagulants (DOACs) are establishing themselves as principle choices for the treatment of a variety of thrombotic disorders. DOACs are also known to affect common coagulation tests which are routinely performed for patients in clinical practice. An understanding of their varied effects is crucial for the appropriate ordering of coagulation tests and their interpretation.</p><p><b>MATERIALS AND METHODS</b>Laboratories in public and private healthcare institutions and commercial sectors were surveyed on coagulation tests offered and their methods. A Medline and bibliography search, including a search on search engines, was performed for publications reporting the effects of dabigatran, apixaban and rivaroxaban on these coagulation tests. These papers were reviewed and summarised for consensus recommendations.</p><p><b>RESULTS</b>Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are variably affected by the DOACs and dependent of the coagulation assays used. Clinicians must know which laboratory has performed these tests to logically interpret test results. A normal PT or aPTT does not exclude the presence of residual DOACs effect. The thrombin time is sensitive to dabigatran but not apixaban or rivaroxaban. Specialised coagulation tests such as thrombophilia tests are also variably affected by the DOACs. All laboratories in Singapore however, employ similar test methods permitting a common set of recommendations for specialised coagulation testing.</p><p><b>CONCLUSION</b>Knowledge of the effects of DOACs on coagulation testing is essential to determine the appropriateness of performing such tests and interpreting them coherently. Practical recommendations which are tests and location-specific are set out in this paper.</p>

Dabigatran approaching the realm of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a serious, immune mediated complication of exposure to unfractionated or low-molecular-weight heparin. Though rare, it is a condition associated with high morbidity and mortality that requires immediate change to alternative anticoagulants for the prevention of life-threatening thrombosis. The direct thrombin inhibitors lepirudin and argatroban are currently licensed for the treatment of HIT. Dabigatran, a novel oral anticoagulant (NOAC) with a similar mechanism of action and effective use in other indications, has recently been proposed as another therapeutic option in cases of HIT. This review serves as an introduction to using dabigatran for this purpose, detailing the clinical aspects of its administration, evidence of its performance compared to other anticoagulants, and the preliminary reports of HIT successfully treated with dabigatran. As the literature on this develops, it will need to include clinical trials that directly evaluate dabigatran against the other NOACs and current treatment options.

Guidance for Endoscopic Procedures in Patients Taking Novel Oral Anticoagulants

Anticoagulant agents are used to reduce the risk of thromboembolic complications in patients with atrial fibrillation or deep vein thrombosis. Several new generation of oral anticoagulants have been approved. These novel oral anticoagulants (NOACs) include direct thrombin inhibitors, dabigatra etexilate, and the direct factor Xa inhibitors, rivaroxaban, apixaban and edoxaban. This review evaluates NOACs-related gastrointestinal bleeding and summarizes the ideal management strategies based on the guideline suggested by American Society for Gastrointestinal Endoscopy.

Readability of medicinal package leaflets: a systematic review / Legibilidade das bulas dos medicamentos: revisão sistemática

OBJECTIVE To review studies on the readability of package leaflets of medicinal products for human use. METHODS We conducted a systematic literature review between 2008 and 2013 using the keywords “Readability and Package Leaflet” and “Readability and Package Insert” in the academic search engine Biblioteca do Conhecimento Online, comprising different bibliographic resources/databases. The preferred reporting items for systematic reviews and meta-analyses criteria were applied to prepare the draft of the report. Quantitative and qualitative original studies were included. Opinion or review studies not written in English, Portuguese, Italian, French, or Spanish were excluded. RESULTS We identified 202 studies, of which 180 were excluded and 22 were enrolled [two enrolling healthcare professionals, 10 enrolling other type of participants (including patients), three focused on adverse reactions, and 7 descriptive studies]. The package leaflets presented various readability problems, such as complex and difficult to understand texts, small font size, or few illustrations. The main methods to assess the readability of the package leaflet were usability tests or legibility formulae. Limitations with these methods included reduced number of participants; lack of readability formulas specifically validated for specific languages (e.g., Portuguese); and absence of an assessment on patients literacy, health knowledge, cognitive skills, levels of satisfaction, and opinions. CONCLUSIONS Overall, the package leaflets presented various readability problems. In this review, some methodological limitations were identified, including the participation of a limited number of patients and healthcare professionals, the absence of prior assessments of participant literacy, humor or sense of satisfaction, or the predominance of studies not based on role-plays about the use of medicines. These limitations should be avoided in future ...

OBJECTIVO Analisar a literatura sobre legibilidade das bulas dos medicamentos para uso humano. MÉTODOS Estudo de revisão sistemática, utilizando as palavras-chave “Readability and Package Leaflet” e “Readability and Package Insert”e a ferramenta de busca académica b-on, que contém diferentes bases bibliográficas. O período analisado foi entre 2008 e 2013. Foram aplicados os critérios PRISMA para redigir o relatório da revisão. Foram incluídos artigos originais de pesquisa quantitativa ou qualitativa. Os critérios de exclusão foram: artigos de opinião ou de revisão, ou escritos numa língua diferente do inglês, português, italiano, francês ou espanhol. RESULTADOS Foram identificados 202 trabalhos, dos quais 180 foram excluídos e 22 selecionados para análise: dois com profissionais de saúde, 10 com pacientes, três sobre reações adversas e sete descritivos. As bulas apresentaram diversos problemas de legibilidade, entre os quais: textos insuficientemente claros e simples, utilização de tamanhos de letra pequenos e número reduzido de ilustrações. Os principais métodos utilizados para avaliar a legibilidade das bulas foram as fórmulas e os testes de legibilidade/usabilidade. Entre as limitações metodológicas, foram identificados aspetos como o recurso a amostras pequenas, a inexistência de fórmulas de legibilidade específicas para a língua em causa, e.g., português, e a realização de testes de compreensão em grupos de pacientes sem avaliação prévia da literacia, dos conhecimentos específicos na área da saúde, das capacidades cognitivas, ou do grau de satisfação dos participantes. CONCLUSÕES Em geral, as bulas apresentaram diversos problemas de legibilidade. Adicionalmente, nesta revisão foram identificadas algumas limitações metodológicas nos estudos revistos (e.g. a participação de um número reduzido de pacientes e profissionais de saúde, a ausência da avaliação prévia da literacia, do humor ou satisfação dos participantes ...

Study on antiplatelet and antithrombin activitives and effective components variation of Puhuang-Wulingzhi before and after compatibility / 中国中药杂志

The changes of bioactive constituents were analyzed for Puhuang-Wulingzhi before and after compatibility and the antiplatelet and antithrombin activitives were evaluated in order to elucidate the scientific and reasonable of Puhuang-Wulingzhi compatibility. UPLC-QTOF-MA-Markerlynx, principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis were used for data analysis and tracking changes of chemical composition during the decocting process. In vitro platelet aggregation induced by ADP, thrombin time(TT) and prothrombin time (PT) were investigated for Puhuang-Wulingzhi before and after compatibility. The results showed that significant differences were found between the mixed decoction and codecoction of Wulingzhi and Puhuang. Five compounds changed obviously were identified as typhaneoside, naringenin, isorhamnetin-3-O-ruinoside, quercetin-3-O-neohesperidoside, kaempferol-3-O-neohesperidoside. The codecoction, comparing with the single decoction, was more significant in antiplatelet aggregation and could prolong thrombin time. In the same crude drug dose, the thrombin time (TT) elongation were greater. These data could provide references for elucidation of bioactive components for this herb pair.

Acute myocardial infarction after switching from warfarin to dabigatran

Dabigatran etexilate is a recently approved direct thrombin inhibitor [DTI], which is superior to warfarin in the prevention of stroke and systemic embolism in patients with atrial fibrillation [AF]. However, dabigatran use is associated with an increased risk of myocardial infarction [MI] compared to warfarin. The mechanisms for this association effect remain speculative. We present a case of an acute MI and cardiac arrest in a patient with chronic AF who had been recently switched from warfarin to dabigatran. Urgent coronary angiography, at St. Michael's hospital [Toronto, Canada], revealed evidence of thromboembolism to the distal posterior descending artery. The patient was treated medically and switched back from dabigatran to warfarin. He did well and was discharged after an uneventful stay in the coronary care unit

Estimation of venous thromboembolism risk with thrombotic biomarkers in cancer patients / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To assess the value of thrombotic biomarkers in estimation of venous thromboembolism (VTE) risk in cancer patients.</p><p><b>METHODS</b>A total of 1473 cancer patients treated in the Tianjin Medical University General Hospital from 2009 to 201 were selected, including 845 males and 628 females in the age of 56 ± 17 years. The activities of von Willebrand factor antigen (vWF:Ag), factor VII (F VII:A), factor VIII (F VIII:A), antithrombin (AT:A), protein C (PC:A) and protein S (PS:A) were assayed using an ACL TOP 700 blood coagulation analyzer. The level of D-dimer (D-D) was assayed using the Biomerieux Mini Vidas Automated Immunoassay Analyzer. Receiver operating characteristic curve (ROC) was used to analyze the diagnostic performance of the parameters. Cox regression analysis model was applied to evaluate the effect on prognosis, and Kaplan-Meier curve was used to implement the survival analysis.</p><p><b>RESULTS</b>The levels of vWF:Ag, D-D, and F VIII:A were significantly higher in all the specified tumor groups ( except the other tumor group ) than that of the control groups (P < 0.05). F VIII:A was significantly higher than that in the control group in all tumor groups except the renal carcinoma, prostatic cancer, lymphoma groups and the other tumor group (P < 0.05). The PC:A level was significantly lower in all tumor patients groups than in the control group, except glioma, breast cancer, gastric carcinoma, renal carcinoma and the other tumors groups (P < 0.05). The PS: A level was significantly lower in all tumor groups than in the control group, except the glioma, breast cancer, prostatic cancer, lymphoma and the other tumors groups (P<0.05). The AT: A level was significantly lower in all tumor groups than in the control group (P<0.05). When the optimum cut-off point of vWF:Ag for VTE diagnosis was 192% in the cancer group, the area under ROC curve = 0.828 (95% CI: 0.716 to 0.939). When the optimum cut-off point of D-dimer for VTE diagnosis was 1484 ng/ml in the cancer group, the area under ROC curve = 0.915 (95% confidence interval: 0. 840 to 0.988). When the optimum cut-off point of PC: A for VTE diagnosis was 75.2% in the cancer group, the area under ROC curve = 0.764 (95% confidence interval: 0.630 to 0.898). The Cox analysis showed that age, surgery, chemotherapy and D-dimer were independent risk factors for VTE event within three months in cancer patients. The cumulative probability of VTE was increased significantly in the cancer patients if whose plasma D-dimer level was over the cut-off value.</p><p><b>CONCLUSIONS</b>The plasma D-dimer level is obviously increased in cancer patients, and there is a relevance to thrombosis risk stratification and VTE cumulative probability. It is with good diagnostic performance, and may be used as an effective marker in estimation of VTE risk within 3 months in cancer patients.</p>

Nuevos anticoagulantes y anestesia regional / New anticoagulants and regional anesthesia

En los últimos años se ha producido un incremento de la práctica de la anestesia regional en pacientes que reciben fármacos que afectan el sistema fisiológico de la coagulación. La posibilidad de producirse un hematoma espinal, luego de una punción neuroaxial, en este tipo de pacientes, intranquiliza al médico anestesista. Por lo tanto, es indispensable que el médico anestesista conozca los mecanismos de acción de los diferentes anticoagulantes, sus propiedades farmacológicas y farmacocinéticas para poder así definir el intervalo entre la administración de los fármacos anticoagulantes y el bloqueo neuroaxial, la retirada del catéter y el reinicio de la anticoagulación permitiendo asociar la anestesia regional y la anticoagulación de forma segura para el paciente¹. Este trabajo tiene como objetivo principal realizar una revisión de los nuevos fármacos anticoagulantes y analizar las recomendaciones existentes como para poder hacer un uso racional y seguro en nuestra práctica diaria.

New anticoagulants and regional anesthesia In recent years there has been an increase in the practice of regional anesthesia in patients receiving drugs affecting the physiological coagulation system. The possibility of a spinal hematoma occurs after neuraxial puncture in these patients, uneasy the anesthesiologist. Therefore, it is essential that the anesthesiologist know the mechanism of action of different anticoagulants, their pharmacological and pharmacokinetic properties to well define the interval between administration of anticoagulants and neuraxial blockade, catheter removal and resetting anticoagulation allowing associate regional anesthesia and anticoagulation safely for patient1. This work has as main objective to carry out a review of the new anticoagulant drugs and analyze existing recommendations as to make rational and safe use in our daily practice.

Analysis of Novel Anticoagulants for Atrial Fibrillation – Pharmacokinetics and Pharmacological Considerations.

Atrial Fibrillation (AF) is the most common arrhythmia. AF is a major risk factor for stoke. Warfarin has been available for more than 60 years and until recently it was the only oral anticoagulant used for the prevention of stroke. Despite the extensive studies and proven efficacy, its utility is limited by multiple factors. Warfarin interacts with a multitude of drugs and foods, has a delayed onset of action, has a narrow therapeutic range, requires routine lab monitoring and exhibits variable responses in patients. The novel agents dabigatran, rivaroxaban and apixaban have the potential to have some of the limitations of warfarin. This article will discuss the pharmacokinetic and pharmacological considerations and different characteristics of the novel anticoagulants when used for the prevention of AF.

Hemodiálisis para remover el anticoagulante dabigatrán en situaciones de urgencia / Hemodialysis to remove anticoagulant dabigatran during emergencies

El dabigatrán es un nuevo inhibidor directo de la trombina, de administración oral, empleado para la prevención de eventos tromboembólicos en pacientes con fibrilación auricular no valvular. A diferencia de la warfarina, no se dispone de un antídoto conocido. La hemodiálisis ha sido sugerida como un método para remover el dabigatrán y reducir el efecto anticoagulante. Se presenta el caso de un paciente con antecedente de fibrilación auricular y medicado con dabigatrán, que fue admitido en el hospital para una cirugía abdominal de urgencia. A las seis horas de la última dosis recibida, los estudios de coagulación mostraban alteración. Ante la falta de antídoto para revertir los efectos, se decidió realizar hemodiálisis. Luego de tres horas de diálisis los parámetros de coagulación tendieron a normalizarse y el paciente fue operado sin presentar hemorragias anormales durante la cirugía o en el postoperatorio.

Dabigatran is an oral anticoagulant from the class of the direct thrombin inhibitors, indicated for prevention of thromboembolic events in patients with non valvular atrial fibrillation. Unlike warfarin, dabigatran has no known antidote. Hemodialysis has been suggested as a method for removing dabigatran and thereby reducing its anticoagulant effect. We report the case of a patient with a known history of atrial fibrillation, treated with dabigatran, who was admitted for emergency abdominal surgery. At six hours after the last dose received, coagulation studies were altered. In absence of an antidote to reverse its effects, it was decided to perform hemodialysis. After three hours of dialysis coagulation parameters were improved and the patient underwent surgery without showing abnormal bleeding during surgery or in the postoperative period.

The functional study of antithrombin L99 mutation / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the molecular mechanisms of inherited antithrombin (AT) deficiency caused by AT L99 mutation.</p><p><b>METHODS</b>Wild type (WT), L99V, L99A, L99I and L99S AT were purified from drosophila expression system. The binding capacity of AT and the low molecular weight heparin sodium was analyzed by the heparin binding assay. Surface plasmon resonance (SPR) was used to detect the binding ability of AT to thrombin (FIIa) or AT to coagulation factor Xa (FXa). The activity of AT(AT∶A)was detected by chromogenic assay.</p><p><b>RESULTS</b>The purified WT and mutant AT were at the same size. No additional band was observed by coomassie blue staining and western blot assay. Compared to the WT AT, the binding abilities of the low molecular weight heparin sodium to the AT L99V, L99A, L99I and L99S were (44.8±3.6)%, (118.9±14.0)%, (15.2±8.8)%, and(23.0±8.2)%, respectively. The binding abilities of FIIa to AT L99V, L99A, L99I and L99S were 13%, 57%, 3%, and 29%, while the binding of FXa to AT L99V, L99A, L99I and L99S were 7%, 51%, 1%, and 25%. The AT∶A of WT, L99V, L99A, L99I and L99S AT were 146.5%, 21.4%, 120.9%, 10.8%, and 39.0%, respectively.</p><p><b>CONCLUSION</b>The binding abilities of AT to heparin, FIIa and FXa were damaged by the L99 mutation, which resulted in decreased AT∶A and inherited AT deficiency.</p>