Dabigatran etexilate for thromboprophylaxis in over 5000 hip or knee replacement patients in a real-world clinical setting

BACKGROUND: Thromboprophylaxis is recommended for patients undergoing total hip or total knee replacement (THR, TKR). An international, open-label, prospective, observational, single-arm study in a routine clinical setting was performed to assess the safety and efficacy of dabigatran etexilate 220 mg once daily in patients undergoing THR or TKR, and in subgroups of patients with potentially increased risk of bleeding or venous thromboembolism (VTE). MATERIALS AND METHODS: Patients were ≥18 years and required to be eligible to receive dabigatran 220 mg once daily (first dose 110 mg 1–4 h after THR/TKR surgery) according to the European Summary of Product Characteristics. The primary safety and efficacy outcomes were incidence of major bleeding events (MBEs), and the composite incidence of symptomatic VTE events and all-cause mortality, respectively. RESULTS: In total, 5292 patients (median age 64 years) were enrolled and received dabigatran (2734 THR and 2558 TKR). Median drug exposure was 31 days (THR 34 days; TKR 27 days). Overall incidence of MBEs was 0.72 % (95 % confidence interval [CI] 0.51, 0.98), and this rate was comparable between types of surgery and was not significantly affected by protocol-defined risk factors. The overall incidence of symptomatic VTE and all-cause mortality was 1.04 % (95 % CI 0.78, 1.35); the only significant risk factor was history of VTE events (odds ratio 5.59; 95 % CI 2.53, 11.08). A post-hoc analysis showed that the incidence of MBEs in this observational study was similar to or lower than those reported in previous phase 3 trials. CONCLUSIONS: Results from this observational study of dabigatran etexilate administered to patients undergoing THR or TKR surgery are reassuring and supportive of those obtained in dabigatran phase 3 trials. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00846807. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12959-016-0082-4) contains supplementary material, which is available to authorized users

Cancer and thrombosis: Managing the risks and approaches to thromboprophylaxis

Patients with cancer are at increased risk of venous thromboembolism (VTE) compared with patients without cancer. This results from both the prothrombotic effects of the cancer itself and iatrogenic factors, such as chemotherapy, radiotherapy, indwelling central venous devices and surgery, that further increase the risk of VTE. Although cancer-associated thrombosis remains an important cause of morbidity and mortality, it is often underdiagnosed and undertreated. However, evidence is accumulating to support the use of low-molecular-weight heparins (LMWHs) in the secondary prevention of VTE in patients with cancer. Not only have LMWHs been shown to be at least as effective as coumarin derivatives in this setting, but they have a lower incidence of complications, including bleeding, and are not associated with the practical problems of warfarin therapy. Furthermore, a growing number of studies indicate that LMWHs may improve survival among patients with cancer due to a possible antitumor effect. Current evidence suggests that LMWHs should increasingly be considered for the long-term management of VTE in patients with cancer

Pharmacogenomic and structural analysis of constitutive G-protein coupled receptor activity

Premi a l'excel·lència investigadora. Àmbit de les Ciències de la Salut. 2008G-protein coupled receptors (GPCRs) respond to a chemically diverse plethora of signal transduction molecules. The notion that GPCRs also signal without an external chemical trigger, i.e. in a constitutive or spontaneous manner, resulted in a paradigm shift in the field of GPCR pharmacology. With the recognition of constitutive GPCR activity and the fact that GPCR binding and signaling can be strongly affected by a single point mutation, GPCR pharmacogenomics obtained a lot of attention. For a variety of GPCRs, point mutations have been convincingly linked to human disease. Mutations within conserved motifs, known to be involved in GPCR activation, might explain the properties of some naturally occurring constitutively active GPCR variants linked to disease. A brief history historical introduction to the present concept of constitutive receptor activity is given and the pharmacogenomic and the structural aspects of constitutive receptor activity are described

Suitability of the use of low-molecular-weight heparins in the prevention of venous thromboembolism

Objetivo: Conocer la prevalencia de prescripción de heparinas de bajo peso molecular (HBPM) en la profilaxis de la enfermedad tromboembólica venosa en un hospital general, así como la adecuación a las recomendaciones de las guías de práctica clínica. Método: Estudio observacional, descriptivo, de corte transversal, tipo indicación-prescripción, con pacientes ingresados en servicios médicos y quirúrgicos. Resultados: Se incluyeron 345 pacientes. La prevalencia de prescripción de HBPM fue del 44,6% (intervalo de confianza [IC] del 95%, 39,3-50,1). Según el nivel de riesgo tromboembólico se encontró adecuación en la decisión de tratar profilácticamente (o no) en 261 casos (75,7%; IC del 95%, 70,7-80,1), en el resto la pauta de actuación no fue la adecuada, destacando 55 pacientes (15,9%; IC del 95%, 12,2-20,2) con riesgo alto a los que no se había prescrito profilaxis (infrautilización), y 29 pacientes (8,4%; IC del 95%, 5,7- 11,8) con riesgo bajo que estaban con profilaxis (sobreutilización). En los pacientes médicos la prevalencia de prescripción fue de 22,6% (IC del 95%, 16,9-29,1) y sólo el 33,3% de los de riesgo tomboembólico alto-moderado recibió profilaxis. La prevalencia de prescripción en cirugía general fue del 84,2% y en traumatología del 91,3%. Conclusiones: En pacientes quirúrgicos el nivel de profilaxis alcanzado es adecuado, pero hay un porcentaje importante de pacientes médicos con riesgo tromboembólico medio-alto, que sigue sin recibir la adecuada profilaxis (infrautilización), a pesar de las recomendaciones de consenso con amplio respaldo científico y profesional.Objective: To investigate the prevalence of low-molecular-weight heparin (LMWH) prescription in venous thromboembolism prophylaxis in a general hospital and the suitability of the recommendations from the clinical practice guidelines. Method: A descriptive, observational and cross-sectional study of the indication-prescription type, carried out on patients admitted to medical departments and for surgery. Results: 345 patients were included. The prevalence of HBPM use was 44.6% (95% CI, 39.3-50.1). Depending on the risk of thromboembolism, the decision to treat prophylactically (or not) was appropriate in 261 cases (75.7%; 95% CI, 70.7-80.1), and the action guidelines were not suitable for the remainder of patients. 55 patients (15.9%; 95% CI, 12.2-20.2) presented a high risk and were not prescribed prophylactically (underuse); and 29 patients (8.4%; 95% CI, 5.7-11.8) at low risk were treated prophylactically (overuse). There was a relationship between the appropriateness of the prescription and the type of patient (p<0.01). In the group of medical patients theprevalence of prescription was 22.6% (95% CI, 16.9-29.1) and only 33.3% of patients with a high to moderate risk of thromboembolism received prophylaxis. The prevalence of prescription in general surgery was 84.2% and 91.3% in traumatology. Conclusions: The degree of prophylaxis is adequate in surgical patients, but there was a significant percentage of medical patients with a high to moderate risk who did not receive suitable prophylaxis (underuse), despite recommendations with scientific and professional backing.Consejería de Salud de la Junta de AndalucíaInstituto de Salud Carlos II

Laboratory testing in patients treated with direct oral anticoagulants: a practical guide for clinicians

Click to hear Dr Baglin's perspective on the role of the laboratory in treatment with new oral anticoagulants SUMMARY: One of the key benefits of the direct oral anticoagulants (DOACs) is that they do not require routine laboratory monitoring. Nevertheless, assessment of DOAC exposure and anticoagulant effects may become useful in various clinical scenarios. The five approved DOACs (apixaban, betrixaban, dabigatran etexilate, edoxaban and rivaroxaban) have different characteristics impacting assay selection and the interpretation of results. This article provides an updated overview on (i) which test to use (and their advantages and limitations), (ii) when to assay DOAC levels, (iii) how to interpret the results relating to bleeding risk, emergency situations and perioperative management, and (iv) what is the impact of DOACs on routine and specialized coagulation assays. Assays for anti-Xa or anti-IIa activity are the preferred methods when quantitative information is useful, although the situations in which to test for DOAC levels are still debated. Different reagent sensitivities and variabilities in laboratory calibrations impact assay results. International calibration standards for all specific tests for each DOAC are needed to reduce the inter-laboratory variability and allow inter-study comparisons. The impact of the DOACs on hemostasis testing may cause false-positive or false-negative results; however, these can be minimized by using specific assays and collecting blood samples at trough concentrations. Finally, prospective clinical trials are needed to validate the safety and efficacy of proposed laboratory thresholds in relation to clinical decisions. We offer recommendations on the tests to use for measuring DOACs and practical guidance on laboratory testing to help patient management and avoid diagnostic errors. ispartof: Journal of Thrombosis and Haemostasis vol:16 issue:2 pages:209-219 ispartof: location:England status: publishe

Studies on the Ultrastructure of Fibrin Lacking Fibrinopeptide B (β-Fibrin)

Release of fibrinopeptide B from fibrinogen by copperhead venom procoagulant enzyme results in a form of fibrin (beta-fibrin) with weaker self-aggregation characteristics than the normal product (alpha beta-fibrin) produced by release of fibrinopeptides A (FPA) and B (FPB) by thrombin. We investigated the ultrastructure of these two types of fibrin as well as that of beta-fibrin prepared from fibrinogen Metz (A alpha 16 Arg----Cys), a homozygous dysfibrinogenemic mutant that does not release FPA. At 14 degrees C and physiologic solvent conditions (0.15 mol/L of NaCl, 0.015 mol/L of Tris buffer pH 7.4), the turbidity (350 nm) of rapidly polymerizing alpha beta-fibrin (thrombin 1 to 2 U/mL) plateaued in less than 6 min and formed a “coarse” matrix consisting of anastomosing fiber bundles (mean diameter 92 nm). More slowly polymerizing alpha beta-fibrin (thrombin 0.01 and 0.001 U/mL) surpassed this turbidity after greater than or equal to 60 minutes and concomitantly developed a network of thicker fiber bundles (mean diameters 118 and 186 nm, respectively). Such matrices also contained networks of highly branched, twisting, “fine” fibrils (fiber diameters 7 to 30 nm) that are usually characteristic of matrices formed at high ionic strength and pH. Slowly polymerizing beta-fibrin, like slowly polymerizing alpha beta-fibrin, displayed considerable quantities of fine matrix in addition to an underlying thick cable network (mean fiber diameter 135 nm), whereas rapidly polymerizing beta-fibrin monomer was comprised almost exclusively of wide, poorly anastomosed, striated cables (mean diameter 212 nm). Metz beta-fibrin clots were more fragile than those of normal beta-fibrin and were comprised almost entirely of a fine network. Metz fibrin could be induced, however, to form thick fiber bundles (mean diameter 76 nm) in the presence of albumin at a concentration (500 mumol/L) in the physiologic range and resembled a Metz plasma fibrin clot in that regard. The diminished capacity of Metz beta-fibrin to form thick fiber bundles may be due to impaired use or occupancy of a polymerization site exposed by FPB release. Our results indicate that twisting fibrils are an inherent structural feature of all forms of assembling fibrin, and suggest that mature beta-fibrin or alpha beta-fibrin clots develop from networks of thin fibrils that have the ability to coalesce to form thicker fiber bundles

Human Neural Cells Transiently Express Reelin during Olfactory Placode Development.

Reelin, an extracellular glycoprotein is essential for migration and correct positioning of neurons during development. Since the olfactory system is known as a source of various migrating neuronal cells, we studied Reelin expression in the two chemosensory olfactory systems, main and accessory, during early developmental stages of human foetuses/embryos from Carnegie Stage (CS) 15 to gestational week (GW) 14. From CS 15 to CS 18, but not at later stages, a transient expression of Reelin was detected first in the presumptive olfactory and then in the presumptive vomeronasal epithelium. During the same period, Reelin-positive cells detach from the olfactory/vomeronasal epithelium and migrate through the mesenchyme beneath the telencephalon. Dab 1, an adaptor protein of the Reelin pathway, was simultaneously expressed in the migratory mass from CS16 to CS17 and, at later stages, in the presumptive olfactory ensheathing cells. Possible involvements of Reelin and Dab 1 in the peripheral migrating stream are discussed.journal articleresearch support, non-u.s. gov't20152015 08 13importe