Venous thrombosis and D-dimers : a new approach in diagnostic management

In the diagnosis of deep vein thrombosis (DVT), serial compression ultrasonography is a safe but inefficient strategy as the overall prevalence of DVT in outpatients suspected of thrombosis is low (17-24%) and only 0.9-2.3% of the patients have DVT detected by the second ultrasound. This inefficiency has lead to the development of new non-invasive strategies by which the need for ultrasound can be reduced by using the pre-test clinical probability (PCP) score and D-dimer measurements. As degradation products of cross-linked fibrin, D-dimer levels will rise in the event of fibrinolysis and are an indirect measurement of thrombus formation. In this thesis, the role of the D-dimer assay in the diagnostic management of DVT is refined. We demonstrate that it is valid to measure D-dimer concentrations using heparin plasma on routine chemical analyzers in stead of the standard citrate plasma. This finding implicates a significant reduction of the turn-around time. Furthermore, we found D-dimer concentrations to remain stable under various (pre)analytic conditions, making comparison of different studies more feasible. In a second study, we studied the course of D-dimer concentrations in patients undergoing embolisation of pulmonary arteries because of arteriovenous malformations. D-dimer concentrations increased almost immediately after formation of a clot and they remained elevated for at least 8 hours after onset. We describe the performance of a rapid latex D-dimer assay in the exclusion of DVT and tried to define variables that might restrict the use of the D-dimer in terms of reduced sensitivity, negative predictive value or specificity. We show that the overall sensitivity and negative predictive value of this D-dimer assay are high. The D-dimer test has a good performance in patients with previous venous thromboembolism, but we do not recommend its use in patients using oral anticoagulants because of reduced sensitivity. The D-dimer tests in patients with cancer and in patients over 70 years old are usually positive and may not be worthwhile in terms of low specificity. The key-question is whether the D-dimer test can replace or reduce the need for CUS in outpatients suspected for having DVT. In a multicenter management study in 812 patients, we show the safety of withholding anticoagulation in patients suspected of having deep venous thrombosis with the combination of a normal D-dimer concentration and a non-high clinical score. This strategy reduces the need for ultrasonography by approximately 30%. In 537 of these patients, extra samples were taken to compare five different D-dimer assays. We show that these D-dimer assays all have a high sensitivity and negative predictive value, but none of the assays reached an NPV of >98% at standard cut-off values. For exclusion of DVT, we therefore recommend combining the D-dimer assay with other non-invasive tests in order to reach failure rates less than 1.0%. The use of D-dimer assays with a very low specificity might not be worthwhile from an economical point of view, as a positive test will necessitate additional testing in the majority of the patients. Venous thromboembolism can be related to malignancy, but routine screening for cancer in every patient with deep venous thrombosis is a matter of debate. We show that high D-dimer concentrations at presentation and during the first days of treatment are indicators of an increased change for overt or occult forms of cancer, especially in patients younger than 60 years

COVID-19-associated coagulopathy and antithrombotic agents—lessons after 1 year

COVID-19 is associated with a high incidence of thrombotic complications, which can be explained by the complex and unique interplay between coronaviruses and endothelial cells, the local and systemic inflammatory response, and the coagulation system. Empirically, an intensified dose of thrombosis prophylaxis is being used in patients admitted to hospital with COVID-19 and several guidelines on this topic have been published, although the insufficiency of high quality and direct evidence has led to weak recommendations. In this Viewpoint we summarise the pathophysiology of COVID-19 coagulopathy in the context of patients who are ambulant, admitted to hospital, and critically ill or non-critically ill, and those post-discharge from hospital. We also review data from randomised controlled trials in the past year of antithrombotic therapy in patients who are critically ill. These data provide the first high-quality evidence on optimal use of antithrombotic therapy in patients with COVID-19. Pharmacological thromboprophylaxis is not routinely recommended for patients who are ambulant and post-discharge. A first ever trial in non-critically ill patients who were admitted to hospital has shown that a therapeutic dose of low-molecular-weight heparin might improve clinical outcomes in this population. In critically ill patients, this same treatment does not improve outcomes and prophylactic dose anticoagulant thromboprophylaxis is recommended. In the upcoming months we expect numerous data from the ongoing antithrombotic COVID-19 studies to guide clinicians at different stages of the disease.http://www.thelancet.com/haematologyam2022Medical Oncolog

Reduced cardiovascular morbidity in patients with hemophilia:results of a 5-year multinational prospective study

Hemophilia is a congenital bleeding disorder caused by low levels of clotting factor VIII or IX. The life expectancy of people with hemophilia (PWH) has increased with the availability of clotting factor concentrates. At the same time, the incidence of cardiovascular disease (CVD) has increased; in retrospective studies, there are conflicting data regarding if, despite this increase, the incidence is still lower than in the general population. We prospectively compared the incidence of CVD in PWH vs the predicted incidence. This prospective, multicenter, observational study included adult PWH (aged &gt;30 years) from The Netherlands and United Kingdom. They were followed up for a 5-year period, and CVD incidence was compared with a predicted event rate based on the QRISK2-2011 CVD risk model. The primary end point was the observed fatal and nonfatal CVD incidence after 5 years compared with the estimated events and in relation to severity of hemophilia. The study included 709 patients, of whom 687 (96.9%) completed 5 years' follow-up or reached an end point. For 108 patients, the QRISK score could not be calculated at inclusion. For the remaining 579, fewer CVD events were observed than predicted: 9 vs 24 (relative risk, 0.38; 95% confidence interval, 0.18-0.80; P 5 .01), corresponding with an absolute risk reduction of 2.4%. Severe hemophilia treated on demand had the highest risk reduction. There was no statistically significant relation between severity of hemophilia and incidence of CVD. In hemophilia, a lower-than-predicted CVD incidence was found, supporting the theory that hemophilia protects against CVD. The study is registered at www.clinicaltrials.gov as #NCT01303900.</p

Bleeding phenotype and diagnostic characterization of patients with congenital platelet defects

Phenotypic characterization of congenital platelet defects (CPDs) could help physicians recognize CPD subtypes and can inform on prognostic implications. We report the analyses of the bleeding phenotype and diagnostic characteristics of a large cohort of adult patients with a confirmed CPD. A total of 96 patients were analyzed and they were classified as Glanzmann thrombasthenia, Bernard-Soulier syndrome, dense granule deficiency, defects in the ADP or thromboxane A2 (TxA2) pathway, isolated thrombocytopenia or complex abnormalities. The median ISTH-BAT bleeding score was nine (IQR 5-13). Heavy menstrual bleeding (HMB) (80%), post-partum hemorrhage (74%), post-operative bleeds (64%) and post-dental extraction bleeds (57%) occurred most frequently. Rare bleeding symptoms were bleeds from the urinary tract (4%) and central nervous system (CNS) bleeds (2%). Domains with a large proportion of severe bleeds were CNS bleeding, HMB and post-dental extraction bleeding. Glanzmann thrombasthenia and female sex were associated with a more severe bleeding phenotype

Congenital platelet disorders and health status-related quality of life

Background: Patients with congenital blood platelet disorders (CPDs) demonstrate a predominantly mucocutaneous bleeding tendency. Repeated bleeds throughout life can have a significant impact on health status-related quality of life (HR-QoL), but few studies have investigated HR-QoL in patients with CPDs. Objectives: To determine HR-QoL in patients with suspected or confirmed CPDs as compared with the general Dutch population and to assess the association between bleeding phenotype and HR-QoL. Methods: Data were derived from the Thrombocytopathy in the Netherlands (TiN) study, a cross-sectional study of individuals suspected for a congenital platelet defect. TiN patients with an increased ISTH Bleeding Assessment Tool (ISTH-BAT) score (>3 in men and > 5 in women) were included for analysis. HR-QoL was assessed with the Short Form (SF)-36 survey. Bleeding symptoms were evaluated with the ISTH-BAT, resulting in a bleeding score. Results: One hundred fifty-six patients were analyzed, of whom 126 (81%) were women. Sixty-two patients (40%) had a confirmed CPD. Compared to the general Dutch population, patients with a suspected or confirmed CPD reported decreased physical functioning, limitations in daily activities due to physical health problems, limitations in social activities, decreased energy levels and fatigue, pain, and lower general health status. HR-QoL was not correlated with the ISTH-BAT score and was similar in patients with a confirmed CPD and those in whom a CPD could not be diagnosed. Conclusion: A bleeding tendency in patients with a suspected or confirmed CPD significantly impacts HR-QoL, independent of a confirmed explanatory diagnosis

Toward responsible clinical n-of-1 strategies for rare diseases

N-of-1 strategies can provide high-quality evidence of treatment efficacy at the individual level and optimize evidence-based selection of off-label treatments for patients with rare diseases. Given their design characteristics, n-of-1 strategies are considered to lay at the intersection between medical research and clinical care. Therefore, whether n-of-1 strategies should be governed by research or care regulations remains a debated issue. Here, we delineate differences between medical research and optimized clinical care, and distinguish the regulations which apply to either. We also set standards for responsible optimized clinical n-of-1 strategies with (off-label) treatments for rare diseases. Implementing clinical n-of-1 strategies as defined here could aid in optimized treatment selection for such diseases

Antithrombotic Treatment in Patients With Hemophilia: an EHA-ISTH-EAHAD-ESO Clinical Practice Guidance

Cardiovascular disease is an emerging medical issue in patients with hemophilia (PWH) and its prevalence is increasing up to 15% in PWH in the United States. Atrial fibrillation, acute and chronic coronary syndromes, venous thromboembolism, and cerebral thrombosis are frequent thrombotic or prothrombotic situations, which require a careful approach to fine-tune the delicate balance between thrombosis and hemostasis in PWH when using both procoagulant and anticoagulant treatments. Generally, PWH could be considered as being naturally anticoagulated when clotting factors are 20 IU/dL in need for any form of antithrombotic therapy, usually treatment without additional clotting factor prophylaxis could be used, but careful monitoring for bleeding is recommended. For antiplatelet treatment, this threshold could be lower with single-antiplatelet agent, but again factor level should be at least 20 IU/dL for dual antiplatelet treatment. In this complex growing scenario, the European Hematology Association in collaboration with the International Society on Thrombosis and Haemostasis, the European Association for Hemophilia and Allied Disorders, the European Stroke Organization, and a representative of the European Society of Cardiology Working Group on Thrombosis has produced this current guidance document to provide clinical practice recommendations for health care providers who care for PWH

Treatment of patients with rare bleeding disorders in the Netherlands:Real-life data from the RBiN study

Background Patients with rare inherited bleeding disorders (RBDs) exhibit hemorrhagic symptoms, varying in type and severity, often requiring only on-demand treatment. Prolonged bleeding after invasive procedures is common. Adequate peri-procedural therapy may reduce this bleeding risk. Objective To describe general treatment plans of RBD patients and evaluate the use of peri-procedural hemostatic therapy. Methods In the Rare Bleeding Disorders in the Netherlands (RBiN) study, RBD patients from all six Dutch Hemophilia Treatment Centers were included. General treatment plans were extracted from patient files. Patients with a dental or surgical procedure in their history were interviewed about use of peri-procedural treatment and bleeding complications. Results Two-hundred sixty-three patients with a rare coagulation factor deficiency or fibrinolytic disorder were included. Eighty-four percent had a documented general treatment plan. General treatment plans of patients with the same RBD were heterogeneous, particularly in factor XI deficiency. Overall, 308 dental and 408 surgical procedures were reported. Bleeding occurred in 50% of dental and 53% of surgical procedures performed without hemostatic treatment and in 28% of dental and 19% of surgical procedures performed with hemostatic treatment. Not only patients with severe RBDs, but also patients with mild deficiencies, experienced increased bleeding without proper hemostatic treatment. Conclusion Large heterogeneity in general treatment plans of RBD patients was found. Bleeding after invasive procedures was reported frequently, both before and after RBD diagnosis, irrespective of factor activity levels and particularly when peri-procedural treatment was omitted. Improved guidelines should include uniform recommendations for most appropriate hemostatic products per RBD and emphasize the relevance of individual bleeding history