The coagulopathy in cirrhosis is associated with thrombosis and bleeding.
To gain better insights into the coagulopathy in patients with cirrhosis, we evaluated plasma thrombin generation and whole ...blood clot formation in a cross-sectional study.
Blood was collected from 73 patients with all-cause cirrhosis (Child-Pugh-A n = 52, B n = 15, C n = 6) and 20 healthy controls. Activity of the coagulation pathways was measured with assays for factor (F) VIIa and FIXa-antithrombin and FXa-antithrombin complexes, respectively. Thrombin generation by calibrated automated thrombography was determined in platelet-poor plasma using a 1 or 5 pm tissue factor trigger with/without thrombomodulin. ROTEM measurements were performed in whole blood triggered with 35 pm tissue factor without/with 175 ng mL(-1) tissue plasminogen activator (the latter refered to as 'tPA-ROTEM').
We observed an increased generation of FVIIa and a moderately elevated amount of FIXa (in complex with antithrombin) without apparent increase in FX activation in patients with cirrhosis. In accordance with this prothrombotic state, markers of thrombin generation potential were also increased upon increasing severity of cirrhosis. In the whole blood clotting assay we observed delayed clot formation and decreased clot strength associated with increased severity of cirrhosis. No significant differences were found for tPA-ROTEM parameters of clot degradation.
These results indicate that cirrhosis patients have an overall procoagulant plasma milieu but a decreased whole blood clot formation capacity with an apparently unaltered resistance to clot lysis.
Ensuring quality has become a daily requirement in laboratories. In haemostasis, even more than in other disciplines of biology, quality is determined by a pre-analytical step that encompasses all ...procedures, starting with the formulation of the medical question, and includes patient preparation, sample collection, handling, transportation, processing, and storage until time of analysis. This step, based on a variety of manual activities, is the most vulnerable part of the total testing process and is a major component of the reliability and validity of results in haemostasis and constitutes the most important source of erroneous or un-interpretable results. Pre-analytical errors may occur throughout the testing process and arise from unsuitable, inappropriate or wrongly handled procedures. Problems may arise during the collection of blood specimens such as misidentification of the sample, use of inadequate devices or needles, incorrect order of draw, prolonged tourniquet placing, unsuccessful attempts to locate the vein, incorrect use of additive tubes, collection of unsuitable samples for quality or quantity, inappropriate mixing of a sample, etc. Some factors can alter the result of a sample constituent after collection during transportation, preparation and storage. Laboratory errors can often have serious adverse consequences. Lack of standardized procedures for sample collection accounts for most of the errors encountered within the total testing process. They can also have clinical consequences as well as a significant impact on patient care, especially those related to specialized tests as these are often considered as "diagnostic". Controlling pre-analytical variables is critical since this has a direct influence on the quality of results and on their clinical reliability. The accurate standardization of the pre-analytical phase is of pivotal importance for achieving reliable results of coagulation tests and should reduce the side effects of the influence factors. This review is a summary of the most important recommendations regarding the importance of pre-analytical factors for coagulation testing and should be a tool to increase awareness about the importance of pre-analytical factors for coagulation testing.
Peripheral artery disease (PAD) patients have an increased cardiovascular risk despite pharmacological treatment strategies. Biomarker research improving risk stratification only focused on known ...atherothrombotic pathways, but unexplored pathways might play more important roles. To explore the association between a broad cardiovascular biomarker set and cardiovascular risk in PAD. 120 PAD outpatients were enrolled in this observational cohort study. Patients were followed for one year in which the composite endpoint (myocardial infarction, coronary revascularization, stroke, acute limb ischemia and mortality) was assessed. Patient data and blood samples were collected upon inclusion, and citrated platelet-poor plasma was used to analyze 184 biomarkers in Olink Cardiovascular panel II and III using a proximity extension assay. Fifteen patients reached the composite endpoint. These patients had more prior strokes and higher serum creatinine levels. Multivariate analysis revealed increased plasma levels of protease-activated receptor 1 (PAR1), galectin-9 (Gal-9), tumor necrosis factor receptor superfamily member 11A (TNFRSF11A) and interleukin 6 (IL-6) to be most predictive for cardiovascular events and mortality. Positive regulation of acute inflammatory responses and leukocyte chemotaxis were identified as involved biological processes. This study identified IL-6, PAR1, Gal-9, TNFRSF11A as potent predictors for cardiovascular events and mortality in PAD, and potential drug development targets.
Essentials
The value of compression therapy in acute phase of deep vein thrombosis is still unclear.
Patients with deep vein thrombosis received acute compression hosiery, bandaging, or none.
Acute ...compression reduces irreversible skin signs related to post thrombotic syndrome.
Compression hosiery may be the preferred choice for the acute phase
Summary
Background
The effectiveness of compression therapy in the acute phase of deep vein thrombosis (DVT) is not yet determined.
Objectives
To investigate the impact of compression therapy in the acute phase of DVT on determinants of the Villalta score, health‐related quality of life (HRQOL), and costs.
Patients/Methods
Eight hundred and sixty‐five patients with proximal DVT (substudy of the IDEAL DVT study) received, immediately after DVT diagnosis, either no compression, multilayer bandaging, or hosiery. In the acute phase and 3 months after diagnosis, HRQOL was determined by use of the EQ‐5D, SF6D, and VEINES‐QoL intrinsic method (VEINES‐QoLint). At 3 months, signs and symptoms were assessed for the total and separate items of the Villalta score, and healthcare costs were calculated.
Results
The compression groups had lower overall objective Villalta scores than the no‐compression group (1.47 standard deviation (SD) 1.570 and 1.59 SD 1.64 versus 2.21 SD 2.15). The differences were mainly attributable to irreversible skin signs (induration, hyperpigmentation, and venectasia) and pain on calf compression. Subjective and total Villalta scores were similar across groups. Differences in HRQOL were only observed at 1 month; HRQOL was better for hosiery (EQ‐5D 0.86 SD 0.18; VEINES‐QoLint 0.66 SD 0.18) than for multilayer compression bandaging (EQ‐5D 0.81 SD 0.23; VEINES‐QoLint 0.62 SD 0.19). Mean healthcare costs per patient were €417.08 (€354.10 to €489.30) for bandaging, €114.25 (€92.50 to €198.43) for hosiery, and €105.86 (€34.63 to €199.30) for no compression.
Conclusions
Initial compression reduces irreversible skin signs, edema, and pain on calf compression. Multilayer bandaging is slightly more effective than hosiery, but has substantially higher costs, without a gain in HRQOL. From a patient and economic perspective, compression hosiery would be preferred when initial compression is applied. Trial registration: IDEAL DVT study ClinicalTrials.gov number, NCT01429714.
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.
A significant proportion of patients with peripheral artery disease (PAD) displays a poor response to aspirin and/or the platelet P2Y12 receptor antagonist clopidogrel. This phenomenon is reflected ...by high on-treatment platelet reactivity (HTPR) in platelet function assays in vitro and is associated with an increased risk of adverse cardiovascular events.
This study aimed to elucidate specific plasma protein signatures associated with HTPR to aspirin and clopidogrel in PAD patients.
Based on targeted plasma proteomics, 184 proteins from two cardiovascular Olink panels were measured in 105 PAD patients. VerifyNow ASPI- and P2Y12-test values were transformed to a continuous variable representing HTPR as a spectrum instead of cut-off level-defined HTPR. Using the Boruta random forest algorithm, the importance of 3 plasma proteins for HTPR in the aspirin, six in clopidogrel and 10 in the pooled group (clopidogrel or aspirin) was confirmed. Network analysis demonstrated clusters with CD84, SLAMF7, IL1RN and THBD for clopidogrel and with F2R, SELPLG, HAVCR1, THBD, PECAM1, TNFRSF10B, MERTK and ADM for the pooled group. F2R, TNFRSF10B and ADM were higher expressed in Fontaine III patients compared to Fontaine II, suggesting their relation with PAD severity.
A plasma protein signature, including eight targets involved in proatherogenic dysfunction of blood cell-vasculature interaction, coagulation and cell death, is associated with HTPR (aspirin and/or clopidogrel) in PAD. This may serve as important systems-based determinants of poor platelet responsiveness to aspirin and/or clopidogrel in PAD and other cardiovascular diseases and may contribute to identify novel treatment strategies.
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•A spectrum of high on-treatment platelet reactivity (HTPR) was established for PAD.•HTPR-associated plasma protein signatures differ between aspirin and clopidogrel.•Pooled HTPR relates to PSGL1, PECAM1, TM, PAR1, TRAILR2, ADM, KIM1 and MERTK.•Higher plasma levels of PAR1, TRAILR2 and ADM are associated with PAD severity.•Systems-based plasma protein signatures may determine antiplatelet therapy response.
Patients with peripheral artery disease (PAD) are treated with preventive strategies to improve the cardiovascular risk. The incidence of cardiovascular events and mortality however remains high in ...PAD populations. We therefore aimed to better characterize PAD patients suffering from cardiovascular events and mortality in order to tailor preventive treatment.
Between 2018 and 2020, 246 PAD outpatients (17 newly diagnosed, 229 with known PAD) were prospectively enrolled in this observational cohort study. Patient data and blood samples were collected after inclusion, and the primary composite endpoint (myocardial infarction, elective coronary revascularization, ischemic stroke, acute limb ischemia, mortality) was evaluated after one year. Secondary outcomes included platelet reactivity, measured using the VerifyNow assay, and medication adherence, assessed using the Morisky Medication Adherence Scale-8 (MMAS-8). Logistic regression models were used to identify associations between characteristics and the occurrence of events.
The cohort comprised 207 patients with claudication and 39 with chronic limb threatening ischemia. Twenty-six (10.6%) patients suffered from an event during follow-up. Prior myocardial infarction (OR 3.3 1.4-7.7), prior ischemic stroke (OR 4.5 1.8-10.9), higher levels of creatinine (OR 5.2 2.2-12.6), lower levels of high-density lipoprotein (OR 4.2 1.5-10.6) and lower haemoglobin levels (OR 3.1 1.3-7.1) were associated with events. Patients with events had more often high on-treatment platelet reactivity (HTPR) on aspirin (OR 5.9 1.4-25.1) or clopidogrel (OR 4.3 1-19.3). High adherence to medication was associated with the occurrence of events (OR 4.1 1-18).
Patients suffering from cardiovascular events and mortality were characterized by prior cardiovascular events as compared to patients who did not experience any events. Antiplatelet therapy was not optimally protective despite high medication adherence, and HTPR was independently associated with the occurrence of events. More research is needed on alternative treatment strategies such as dual antiplatelet therapy or combinations with anticoagulant drugs.
The Medical Ethics Committee (METC) of the MUMC+ approved the study (NL63235.068.17) and the study was registered in the Netherlands Trial Register ( NTR7250 ).
Post-thrombotic syndrome (PTS) occurs in 20-50% of patients after a deep venous thrombosis (DVT). It is difficult to accurately predict which patients will develop PTS. Biomarkers could be a valuable ...tool for PTS risk assessment.
To investigate whether increased levels of factor (F)VIII, C-reactive protein (CRP) or D-dimer, over time, are associated with the development of PTS in patients after an acute DVT.
PTS status was assessed using the Villalta scale. Blood sampling was performed at three points during follow-up.
A cohort of 228 consecutive patients was included after an acute DVT. At T1 (12 months after index DVT), both levels of D-dimer (median 725 ng mL(-1) interquartile range, IQR 400-1400 vs. 378 ng mL(-1) 251-652 P=0.004) and CRP (median 3.9 mg L(-1) IQR 1.6-8.5 vs. 2.4 mg L(-1) 1.0-4.3 P=0.018) were increased in patients with PTS, compared with patients without PTS. Factor (F)VIII was not associated with PTS. In the multivariate logistic regression analysis, varicosities (odds ratio OR 13.4 95% confidence interval CI 3.0-59.1 P=0.001), a previous ipsilateral DVT (OR 6.3 95% CI 1.5-26.9 P=0.012) and CRP>5 mg L(-1) on T1 (OR 8.0 95% CI 2.4-26.4 P=0.001) were significantly associated with PTS.
Besides previous ipsilateral DVT and varicosities, CRP>5 mg L(-1) at T1 was strongly and independently associated with PTS. Persistent inflammation rather than hypercoagulability might be the most important etiological factor in PTS, and may be a target for future therapy. The development of a risk score for PTS, including both clinical risk factors and biomarker levels, such as CRP, might be desirable.
Although the link between blood coagulation and atherogenesis has been long postulated, only recently, and through the extensive work on transgenic mice, crossbred on an atherogenic background, has ...the direction of this interaction become visible. In general, hypercoagulability in mice tends to increase atherosclerosis, whereas hypocoagulability reduces the atherosclerotic burden, depending on the mouse model used. The information on a direct relationship between coagulation and atherosclerosis in humans, however, is not that clear. Almost all coagulation proteins, including tissue factor, are found in atherosclerotic lesions in humans. In addition to producing local fibrin, a matrix for cell growth, serine proteases such as thrombin may be very important in cell signaling processes, acting through the activation of protease-activated receptors (PARs). Activation of PARs on vascular cells drives many complex processes involved in the development and progression of atherosclerosis, including inflammation, angiogenesis, and cell proliferation. Although current imaging techniques do not allow for a detailed analysis of atherosclerotic lesion phenotype, hypercoagulability, defined either by gene defects of coagulation proteins or elevated levels of circulating markers of activated coagulation, has been linked to atherosclerosis-related ischemic arterial disease. New, high-resolution imaging techniques and sensitive markers of activated coagulation are needed in order to study a causal contribution of hypercoagulability to the pathophysiology of atherosclerosis. Novel selective inhibitors of coagulation enzymes potentially have vascular effects, including inhibition of atherogenesis through attenuation of inflammatory pathways. Therefore, we propose that studying the long-term vascular side effects of this novel class of oral anticoagulants should become a clinical research priority.
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