Direct oral anticoagulants (DOACs) have been approved to treat and prevent thrombotic events. However, they are not yet labeled for use in patients with active cancers. Myeloproliferative neoplasms ...(MPNs) are clonal chronic disorders with a high incidence of thrombotic events, for which low-dose aspirin (LDA) is the standard drug treatment. We analyzed efficacy and safety of DOACs prescription in patients treated for MPNs. An MPN database, the OBENE registry, was established at our institution. We collected biological and clinical data from diagnosis to last follow-up for every patient included in this study. Thrombotic and hemorrhagic events and hematologic evolutions were categorized as major events in the database. Of the 760 MPN patients in the OBENE registry, 25 (3.3%) were treated with a DOAC. Median follow-up duration was 2.1 years (0.12–4.3 years). The reasons for prescribing DOACs were atrial fibrillation and thrombotic events for 13 and 12 patients, respectively. We only observed one thrombotic event (4%) and three major hemorrhagic events (12%). A case–control study did not detect a significant difference in thrombotic or hemorrhagic events in patients treated with LDA and DOACs. These preliminary results suggest that DOACs may be highly efficient and safe for use in MPN patients.
Essential thrombocythemia (ET) and polycythemia vera (PV) are myeloproliferative neoplasms (MPN) with an increased risk of arterial and venous thrombosis. Aspirin is recommended to reduce this risk, ...but resistance to antiplatelet therapy seems to hamper its efficacy in some patients. We have previously shown that multiple electrode aggregometry (MEA) was a valuable tool to assess aspirin resistance in MPN. In this study, MEA was used to assess the reduction in aspirin resistance after bi-daily (BID) aspirin intake or cytoreduction.
Fifty one MPN patients (31 ET and 20 PV) receiving 75 mg aspirin once daily (OD) or BID, with or without cytoreductive treatment, were analyzed. Aspirin resistance was assessed using whole blood MEA (Multiplate®, Roche Diagnostics, Meylan, France).
In all patients, global aspirin resistance consisted mainly of turnover resistance (TOR). 94% of patients with OD aspirin intake and without cytoreduction displayed biological aspirin resistance. By switching to a BID aspirin regimen, the proportion of resistant patients reduced to 47%. Cytoreduction also contributed to reduce aspirin resistance in a similar way (50% of aspirin resistant patients). Combining cytoreduction and BID aspirin regimen was the most efficient way to reduce aspirin resistance yielding to 12% resistant patients. Moreover, a nonlinear correlation was observed between TOR and naive platelet counts regardless of aspirin regimen. Last, mutational status did not seem to affect TOR.
This study confirmed that BID aspirin is biologically more effective than OD aspirin in reduction of aspirin resistance. The latter was achieved through a reduction in TOR which was also decreased by cytoreductive therapy.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
P2Y12 receptor inhibitors are antiplatelet agents commonly prescribed in the treatment of coronary artery disease. Their efficacy can be limited by high on-treatment platelet reactivity (HPR), which ...can be evaluated by different biological assays. Most commonly, HPR is evaluated by flow cytometric vasodilator-stimulated phosphoprotein-phosphorylation (VASP-P) assay, which can be time consuming. To evaluate the potential interest of novel technologies, we compared four different assays. Ninety patients receiving P2Y12 inhibitors were included. Four technologies were evaluated: the current standard test measuring VASP-P by flow cytometry, the historical reference test based on light transmittance aggregation (LTA), and two relatively novel techniques: whole blood multiple electrode aggregometry (MEA) and platelet function analyzer (PFA), which are less time consuming. The three latter tests were compared with the VASP-P assay as a reference using receiver operating characteristics (ROC) analysis: LTA has an excellent comparability with the VASP test (ROC AUC > 0.9); the other two tests (multiplate and PFA) have only satisfactory comparability (ROC AUC around 0.7) and therefore may not replace the VASP "gold standard" test, if importance is attached to a quantitative assessment of the substitution parameter of VASP. Nevertheless, if a binary approach of the anti-aggregation result is sought, then one can conclude that the three tests are equivalent since Cohen's kappa coefficients are very close for the three tests (k = 0.548 for LTA; k = 0.554 for MEA; k = 0.570 for PFA/P2Y), and a similar proportion of patients are misclassified (15% for LTA, 14% for MEA, and 13.6% for PFA). Discriminant factor analysis using all the parameters provided by each test did not improve the diagnostic performance of MEA or PFA. In conclusion, only LTA shows a good comparability to the VASP assay using ROC curve analysis, probably because misclassified patients have results close to the cutoff values. All three tests have moderate agreement regarding the classification of patients as responders to P2Y12 inhibition.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Obese patients are in a hypercoagulable state relative to normal-weight patients. Low-grade inflammation may be a key factor for this condition.
Our study aimed to compare the coagulability state of ...morbidly obese patients before and 1 year after bariatric surgery (BS) using the Thrombin Generation (TG) test, a validated method to assess coagulation in vitro.
University hospital.
All patients undergoing BS between September 1, 2014 and April 30, 2015 were eligible for this prospective study (n = 42). Two distinct reagents were used for TG initiation based on the tissue factor concentration (Reagents LOW and HIGH). The main outcomes were endogenous thrombin potential (ETP) and peak height of TG. The rate of follow-up after one year was 97%.
One year after surgery, %weight loss was 32.5±8.4%; CRP decreased from 9.0 (3.7-12.9) to 1.1 (0.3-2.8) mg/mL (P<.001) and fibrinogen from 4.2±.8 to 3.5±.8 g/L (P<.001). The ETP (%) decreased from (108.0 (95.0-117.0) to 78.0 (71.0-98.0) (P<.001) (LOW reagent) and from 113.0 (103.0-134.0) to 96.0 (86.0-107.0) (P<.001) (HIGH reagent). Peak height (%) decreased from (117.0 (92.0-139.0) to 82.0 (70.0-111.0) (P = .003) (LOW reagent) and from 106.0 (96.0-118.0) to 97.0 (87.8-105.2) (P = .003) (HIGH reagent).
Our study shows a significant reduction in TG potential one year after BS in morbidly obese patients. Reduction of low grade inflammation may be one of the underlying mechanisms.
An acute traumatic coagulopathy (ATC) is observed in about one third of severely traumatized patients. This early, specific, and endogenous disorder is triggered by the association of trauma and ...hemorrhage. The early phase of this condition is characterized by the expression of a bleeding phenotype leading to hemorrhagic shock and the late phase by a prothrombotic profile leading to multiple organ failure. The physiopathology of this phenomenon is still poorly understood. Hypotheses of disseminated intravascular coagulation, activated protein C-mediated fibrinolysis, fibrinogen consumption, and platelet functional impairment were developed by previous authors and continue to be debated. The objective of this study was to observe general hemostasis disorders in case of ATC to confront these hypotheses.
Four groups of 15 rats were compared: C, control; T, trauma; H, hemorrhage; and TH, trauma and hemorrhage. Blood samples were drawn at baseline and 90 min. Thrombin generation tests, platelet aggregometry, and standard hemostasis tests were performed.
Significant differences were observed between the baseline and TH groups for aPTT (17.9 ± 0.8 s vs 24.3 ± 1.4 s,
< 0.001, mean ± SEM), MAP (79.7 ± 1.3 mmHg vs 43.8 ± 1.3 mmHg,
< 0.001, mean ± SEM), and hemoglobin (16.5 ± 0.1 g/dL vs 14.1 ± 0.3 g/dL,
< 0.001, mean ± SEM), indicating the presence of an hemorrhagic shock due to ATC. Compared to all other groups, coagulation factor activities were decreased in the TH group, but endogenous thrombin potential was (paradoxically) higher than in group C (312 ± 17 nM/min vs. 228 ± 23 nM/min;
= 0.016; mean ± SEM). We also observed a subtle decrease in platelet count and function in case of ATC and retrieved an inversed linear relationship between fibrinogen concentration and aPTT (intercept, 26.53 ± 3.16; coefficient, - 3.40 ± 1.26; adjusted
: 0.1878;
= 0.0123).
The clinical-biological profile that we observed, combining normal thrombin generation, fibrinogen depletion, and a hemorrhagic phenotype, reinforced the hypothesis of activated protein C mediated-fibrinolysis. The key role of fibrinogen, but not of the platelets, was confirmed in this study. The paradoxical preservation of thrombin generation suggests a protective mechanism mediated by rhabdomyolysis in case of major trauma. Based on these results, we propose a new conception concerning the pathophysiology of ATC.
We retrospectively analysed the data files of 171 adults and 87 children/adolescents with severe haemophilia, except for 14 patients (moderate; minor) (1), to develop a global population ...pharmacokinetic (PK) model for eight factors VIII (FVIII) that could estimate individual PK parameters for targeting the desired level of FVIII activity (FVIII:C); and (2) to compare half-life (HL) in patients switching from a standard half-life (SHL) to an extended half-life (EHL) and evaluate the relevance of the switch. One-stage clotting assay for the measurement of FVIII activity (FVIII:C, IU/mL) was used for population PK modelling. The software, Monolix version 2019R1, was used for non-linear mixed-effects modelling. A linear two-compartment model best described FVIII:C. The estimated PK parameters (between-subject variability) were: 2640 mL (23.2%) for volume of central compartment (V1), 339 mL (46.8%) for volume of peripheral compartment (V2), 135 mL/h for Q (fixed random effect), and 204 mL/h (34.9%) for clearance (Cl). Weight, age, and categorical covariate EHL were found to influence Cl and only weight for V1. This model can be used for all of the FVIII cited in the study. Moreover, we demonstrated, in accordance with previous studies, that Elocta had longer half-life (EHL) than SHL (mean ratio: 1.48) as compared to Advate, Factane, Kogenate, Novoeight, and Refacto.
Our single-center prospective study compared two methods of D-dimer determination used in the exclusion of pulmonary embolism: bioMérieux method, VIDAS® D-Dimer Exclusion™ II, and Diagnostica Stago ...method, STA®-Liatest® D-Di Plus. For each of these two methods, we calculated optimized variable cutoffs based on fibrinogen and/or age to improve the specificity of the methods.
2530 patients admitted to the Emergency Department of the Brest University Hospital for suspected pulmonary embolism were included in this study. The comparison of the two methods was performed by calculating their different characteristics: sensitivity, specificity and negative predictive value for different cutoffs systems: fixed or age-adjusted according to Douma et al. An optimization of the variable cutoff according to age and fibrinogen was then performed.
The two methods VIDAS and STAGO are approximately equivalent in terms of performance even if the STAGO method presents a better specificity (57.1 %) at the fixed cutoff of 0.5 μg/mL. The adoption of age-adjusted, fibrinogen-adjusted or doubly-adjusted (age and fibrinogen) cutoffs, significantly improves the specificity of the tests without affecting their excellent sensitivity. These specificities peak respectively at 75.8 % and 76 % for the VIDAS and STAGO tests when using a doubly-adjusted, age and fibrinogen, cutoff, i.e. a gain in specificity of approximately 10 % compared with the age-adjusted cutoff of Douma et al. and of approximately 20 % compared with the fixed cutoff of 0.5 μg/mL.
Adopting an optimized variable cutoff based on fibrinogen and/or age significantly improves specificity of D-dimer methods for pulmonary embolism exclusion.
•A variable cutoff based on fibrinogen or age improves specificity of D-dimer methods.•This new variable cutoff may generate substantial savings for healthcare systems.•VIDAS and STAGO D-Dimer methods are comparable for pulmonary embolism exclusion.
The rare vaccine-induced immune thrombotic thrombocytopenia that may follow adenovirus-based Covid-19 vaccination resembles heparin-induced thrombocytopenia, but rapid assays for anti-PF4 antibodies ...used to diagnose HIT may be negative in patients with VITT. The PF4–serotonin release assay appears to detect the IgG antibodies to PF4–PVS that mediate this condition.
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