[Treatment of haemophilia in Austria]. / Hämophilie-Behandlung in Österreich.

This guideline is intended to provide practical guidance for the diagnosis and treatment of haemophilia in Austria. Few randomized controlled interventional trials are available addressing the treatment of haemophilia, therefore recommendations are usually based on low level of evidence and represent expert consensus.This guideline is based on the WFH guideline, published in 2020, and adapted according to the national circumstances and experience.It includes recommendations and suggestions for diagnosis and follow-up visits and pharmacological therapies for treatment and prophylaxis. Further topics comprise special aspects in children and adults with severe haemophilia, outcome measurement, and management of trauma, special bleedings and interventions, including dental procedures, inhibitors, management of haemophilia carriers, and psychosocial aspects.

Evaluation of bone mineral density and bone turnover in children on anticoagulation.

Background: Childhood and adolescence are critical periods of bone mineral acquisition. Children on anticoagulation (AC) might have an increased risk for reduced bone mineral density (BMD). Risk factors for impaired bone accumulation include chronic diseases, immobility, and medication. Vitamin K (VK) deficiency reflected by undercarboxylated osteocalcin levels (ucOC) has been identified as a predictor of osteoporosis and fractures. Data on bone health in children under AC are sparse. Aims: To evaluate BMD in children on AC and characterize the risk factors of low BMD, including VK and Vitamin D (VD) status. Methods: Single-center cross-sectional study of clinical, biochemical, and densitometric parameters. Assessment of VK surrogate parameters included ucOC and matrix gla protein (MGP). Results: A total of 39 children (4-18 years; 12 females) receiving AC were included, 31 (79%) on VK antagonists and 8 (21%) on direct oral anticoagulants. Overall, BMD was decreased for both the lumbar spine (LS; -0.7SDS) and total body less head (TBLH; -1.32SDS) compared with pediatric reference data. Significant associations were found between early pubertal development and TBLH-BMD, and between BMI and LS-BMD. VK surrogate parameters were highly related to patients' age and pubertal development. Neither serum parameters nor AC-related factors predicted BMD. VD was detected in 10/39 patients with lower values during puberty. Conclusion: Our data indicate BMD reduction in pediatric patients on AC. Although AC-related factors did not predict reduced BMD, low BMI and pubertal stages represented important risk factors. Awareness of risk factors for low BMD and high prevalence of VD deficiency during puberty could contribute to the improvement of bone health in this vulnerable patient group.

SARS-CoV-2 Associated Pediatric Inflammatory Multisystem Syndrome With a High Prevalence of Myocarditis - A Multicenter Evaluation of Clinical and Laboratory Characteristics, Treatment and Outcome.

Introduction: Pediatric inflammatory multisystem syndrome - temporally associated with SARS-CoV-2 infection (PIMS -TS) comprises a new disease entity having emerged after the COVID-19 outbreak in 2019. Materials and Methods: For this multicenter, retrospective study children between 0 and 18 years with PIMS-TS between March 2020 and May 2021 were included, before availability of vaccination for children. Frequent SARS-CoV-2 variants at that period were the wildtype virus, alpha, beta and delta variants. Inclusion criteria were according to the PIMS-TS criteria, proposed by the Royal College of Pediatrics and WHO. Study aim was to review their clinical, laboratory and echocardiographic data with a focus on cardiac involvement. Results: We report 45 patients, median age 9 years, 64% male. SARS-CoV-2 antibodies were positive in 35/41 (85%). PIMS occurrence followed local COVID-19 peak incidence periods with a time lag. The most common symptoms at presentation were fever (98%), abdominal pain (89%) and rash (80%). Fever history of > 5 days was associated with decreased left ventricular function (p = 0.056). Arterial hypotension and cardiac dysfunction were documented in 72% patients, increased brain natriuretic peptide in 96% and increased cardiac troponin in 64% of the children. Echocardiography revealed mitral valve regurgitation (64%), coronary abnormalities (36%) and pericardial effusions (40%). Increased NT-proBNP was significantly associated with the need of inotropics (p < 0.05), which were necessary in 40% of the patients. Treatment comprised intravenous immunoglobulin (93%), systemic steroids (84%) and acetylsalicylic acid (100%; 26/45 started with high dosages). For insufficient response to this treatment, five (11%) children received the interleukin-1 receptor antagonist anakinra. All patients were discharged with almost resolved cardiac signs. Conclusion: Our analysis of non-vaccinated children with PIMS-TS demonstrates that a considerable number have associated myocarditis requiring intensive care and inotropic support. Most children showed adequate response to intravenous immunoglobulin and steroids and good recovery. Further evaluation of pediatric patients with COVID-19 associated diseases is required to evaluate the impact of new virus variants.

Pain management in hemophilia: expert recommendations.

INTRODUCTION: As a typical consequence of bleeding into muscles and joints, patients with severe hemophilia suffer from acute and chronic pain. In spite of its high prevalence, pain in this patient group is not always sufficiently considered or treated in an effective manner. AIM: The recommendations presented in this paper address possible improvements in pain management in hemophilia patients and particularities that have to be taken into account in this patient group. METHOD: The manifold aspects of pain management in hemophilia patients were discussed within the framework of an expert meeting. Based on the available literature and the experts' clinical experience, the participants developed a set of recommendations presented in this paper. RESULTS: Pain management in patients with hemophilia is often insufficient, a fact that not only influences the patients' quality of life but also implies the risk of difficult to manage chronic pain. Both the prevalent polypharmacy (due to comorbidities) as well as the underlying disease itself present special challenges to pain therapy in this patient group. The present review and recommendations are intended to support medical professionals in recognising the risks of pain chronicity, applying basic principles of multimodal pain therapy, including the options of psychological intervention and modalities of physical medicine in therapy concepts, and reaching a comprehensive understanding of the range of analgesic options available.

Safety and efficacy of anticoagulant therapy in pediatric catheter-related venous thrombosis (EINSTEIN-Jr CVC-VTE).

Anticoagulant treatment of pediatric central venous catheter-related venous thromboembolism (CVC-VTE) has not been specifically evaluated. In EINSTEIN-Jr, 500 children with any VTE received rivaroxaban or standard anticoagulants. A predefined analysis of the CVC-VTE cohort was performed. Children with CVC-VTE (age, birth to 17 years) were administered rivaroxaban or standard anticoagulants during the 1-month (children <2 years) or 3-month (all other children) study period. Predefined outcomes were recurrent VTE, change in thrombotic burden on repeat imaging, and bleeding. Predictors for continuation of anticoagulant therapy beyond the study period were evaluated. One hundred twenty-six children with symptomatic (n = 76, 60%) or asymptomatic (n = 50, 40%) CVC-VTE received either rivaroxaban (n = 90) or standard anticoagulants (n = 36). There was no recurrent VTE (0%; 95% confidence interval [CI], 0.0%-2.8%). Three children had the principal safety outcome: none had major bleeding and 3 children had clinically relevant nonmajor bleeding (2.4%; 95% CI, 0.7%-6.5%), all in the rivaroxaban arm. Complete or partial vein recanalization occurred in 57 (55%) and 38 (37%) of 103 evaluable children, respectively. Results were similar for symptomatic and asymptomatic CVC-VTE. Continuation of anticoagulant therapy beyond the study period occurred in 61 (48%) of children and was associated with residual VTE but only in children <2 years (odds ratio [OR], 20.9; P = .003) and continued CVC use (OR, 6.7; P = .002). Anticoagulant therapy appeared safe and efficacious and was associated with reduced clot burden in most children with symptomatic or asymptomatic CVC-VTE. Residual VTE and continued CVC use were associated with extended anticoagulation. This trial was registered at www.clinicaltrials.gov as #NCT02234843.

Genetic determinants of VWF clearance and FVIII binding modify FVIII pharmacokinetics in pediatric hemophilia A patients.

Factor VIII (FVIII) pharmacokinetic (PK) properties show high interpatient variability in hemophilia A patients. Although previous studies have determined that age, body mass index, von Willebrand factor antigen (VWF:Ag) levels, and ABO blood group status can influence FVIII PK, they do not account for all observed variability. In this study, we aim to describe the genetic determinants that modify the FVIII PK profile in a population of 43 pediatric hemophilia A patients. We observed that VWF:Ag and VWF propeptide (VWFpp)/VWF:Ag, but not VWFpp, were associated with FVIII half-life. VWFpp/VWF:Ag negatively correlated with FVIII half-life in patients with non-O blood type, but no correlation was observed for type O patients, suggesting that von Willebrand factor (VWF) half-life, as modified by the ABO blood group, is a strong regulator of FVIII PK. The FVIII-binding activity of VWF positively correlated with FVIII half-life, and the rare or low-frequency nonsynonymous VWF variants p.(Arg826Lys) and p.(Arg852Glu) were identified in patients with reduced VWF:FVIIIB but not VWF:Ag. Common variants at the VWF, CLEC4M, and STAB2 loci, which have been previously associated with plasma levels of VWF and FVIII, were associated with the FVIII PK profile. Together, these studies characterize the mechanistic basis by which VWF clearance and ABO glycosylation modify FVIII PK in a pediatric population. Moreover, this study is the first to identify non-VWF and non-ABO variants that modify FVIII PK in pediatric hemophilia A patients.

Direct oral anticoagulants: What will be their role in children?

Thrombotic events in children differ from those in adults in epidemiology, pathophysiology, and anatomical location. However, anticoagulation in children is mostly based on evidence from adults while scarce evidence exists from children. The classical anticoagulants currently used in children have several limitations, resulting in the need for regular monitoring. Several direct oral anticoagulants (DOACs) are now authorized for adults in whom they have established efficacy and safety without the need for monitoring. Given their pharmacological properties and the special characteristics of children requiring anticoagulation, the DOACs have the potential to be particularly suitable for children. All currently approved DOACs have paediatric development plans, targeting various indications for prevention and treatment of thrombosis. Paediatric formulations are being developed and systematic age-specific dosing information will be generated. Whether therapeutic drug monitoring will be necessary in certain situations in children remains to be elucidated. The results of ongoing clinical studies still need to demonstrate whether there is a positive benefit-risk balance in all targeted paediatric indications and age-groups, particularly in indications that have not been explored in adults, such as catheter-related thrombosis or congenital heart disease. If the advantages of DOACs bear out in the results of the current paediatric studies, they will likely be used widely in children. As of now, the DOACs should not be used routinely in children as there is still insufficient information on appropriate dosing, safety and efficacy. The paediatric community is encouraged to promote participation of children and adolescents into the multiple ongoing studies of DOACs.

Epidemiology and Treatment of Patients with Haemophilia in Austria-Update from the Austrian Haemophilia Registry.

The Austrian Haemophilia Registry collects epidemiological data on patients with haemophilia, on treatment modalities and potential side effects. The Registry covers more than 85% of the assumed total number of haemophilia patients in Austria. This report summarizes data on 753 patients: 84.3% (635) have haemophilia A and 15.7% (118) have haemophilia B. Patients' median age is 34 years (range: 1-93 years). Of the total cohort, 39.0% (294) patients have severe haemophilia, 11.3% (85) moderate haemophilia, and 49.4% (372) mild haemophilia. Of the patients with severe haemophilia, 38.4% (113) have been infected with hepatitis C virus (HCV) and 12.6% (37) are human immunodeficiency virus (HIV) positive. Overall, 10.6% (67) of patients with haemophilia A and 1.7% (2) of those with haemophilia B have had an inhibitor in their history. Among patients with severe haemophilia, 68.4% (201) receive prophylaxis and 28.6% (84) receive on-demand therapy. There are 65.0% (191) patients with severe haemophilia who are treated with recombinant products. In conclusion, most patients with severe haemophilia receive prophylactic treatment. HCV and HIV infections are still important issues in the Austrian haemophilia population.

Homozygous antithrombin deficiency type II causing neonatal thrombosis.

We report four children from different families with homozygous antithrombin (AT) deficiency type II affecting the heparin binding site (p.Leu131Phe mutation). All children had severe spontaneous venous and/or arterial thromboembolic events shortly after birth. This report intends to raise awareness among clinicians about this rare but severe condition. When thrombosis occurs in an otherwise healthy newborn, a severe congenital thrombophilic disorder should be considered. In homozygous AT deficiency type II, AT activity is typically reduced but may also be in the normal range, posing a diagnostic challenge. Rapid diagnosis is important to initiate appropriate therapy. Standard anticoagulation with heparin may prove ineffective in severe AT deficiency, requiring substitution of AT concentrate and early switch to alternative anticoagulants such as vitamin K antagonists.

[Treatment of haemophilia in Austria]. / Hämophiliebehandlung in Österreich.

This guideline which is endorsed by the Austrian Society of Haemophilia, the Austrian Society of Paediatrics, and the Austrian Society of Haematology & Medical Oncology is intended to give a clear and practical guidance for diagnosing and treating haemophilia in Austria. In the treatment of haemophilia there are few controlled interventional trials, and recommendations usually have a rather low level of evidence.The main basis for this paper are the new international guidelines by the World Federation of Hemophilia, published in 2013. These were adapted according to the local situation and experience.Covered topics are diagnostics, control visits, pharmacological treatment options, prophylaxis and treatment in children and adults, possible problems arising in haemophilia carriers and special aspects like home therapy, options for venous catheters, management of various traumas, bleedings and interventions, including dental procedures, and last not least inhibitors and their treatment.

Monitoring unfractionated heparin in children: a parallel-cohort randomized controlled trial comparing 2 dose protocols.

Monitoring unfractionated heparin (UFH) is crucial to prevent over- or under-anticoagulation. However, the optimal parameters for monitoring UFH in children are not well established. The study objectives were to investigate (1) the relationship between UFH dose and its anticoagulant effect as assessed by anti-Xa, activated partial thromboplastin time (aPTT) and activated clotting time (ACT); (2) other factors influencing UFH effect; (3) the agreement between the assays; and (4) the association between UFH effect and clinical outcome. HEARTCAT was a parallel-cohort randomized controlled trial comparing high-dose (100 U/kg bolus followed by age-based continuous infusion in randomized children) vs low-dose UFH (50 U/kg bolus) during cardiac catheterization in children. Blood samples were drawn before and after UFH administration at 30, 60, and 90 minutes. Four-hundred and two samples of 149 patients were evaluable. Anti-Xa, aPTT, and ACT all showed good discrimination between UFH doses. Regression models demonstrated the following determinants of UFH effect: UFH dose, age, baseline antithrombin (for anti-Xa), and baseline levels of aPTT and ACT, respectively. UFH effects were lower in infants compared with older children, which was more pronounced at low-dose than at high-dose UFH. Agreement between the 3 assays was poor. Most aPTT values were above therapeutic range or beyond measuring limit and thus of limited value for UFH monitoring. No association of UFH dose or effect with clinical outcome could be observed. In conclusion, all assays reflected a significant UFH dose-effect relationship, however, with poor agreement between the respective tests. The age-dependency of UFH effect was confirmed. Notably, the influence of age on UFH effect was dose-dependent.

Anticoagulation in children undergoing cardiac surgery.

Advances in medical and surgical care have resulted in improved survival of patients with congenital heart disease (CHD). Parallel to these progresses, an increasing number of immediate and long-term complications have been recognized. One important complication in CHD is the development of thrombosis. Children with a single functional cardiac ventricle usually require sequential steps of surgery: the initial Blalock-Taussig shunts (BTS) during the neonatal period, followed by the Glenn shunt, and finally, the Fontan shunt, the "definitive palliative" procedure. Surgery mostly involves cardiopulmonary bypass (CPB), which also affects the coagulation system and causes an inflammatory response. This article will review surgical procedures, such as BTS, Glenn shunt, and Fontan shunt, prosthetic mechanical valves, and CPB, and their risk of thrombotic complications. There is insufficient evidence and no consensus for optimal anticoagulant prophylaxis or treatment in children with CHD. Current recommendations are mostly based on adult data.

Incidence and diagnosis of thrombosis in children with short-term central venous lines of the upper venous system.

OBJECTIVES: Deep venous thrombosis in children is frequently related to central venous lines. Study objectives were to determine objectively the incidence of deep venous thrombosis in children with short-term central venous lines and to assess the diagnostic value of venography, venous ultrasonography, and echocardiography, in a prospective cohort study. METHODS: Consecutive children with congenital heart disease requiring short-term central venous lines in the upper venous system were screened systematically for deep venous thrombosis by using venography, venous ultrasonography, and echocardiography, according to standardized protocols. RESULTS: The study population consisted of 90 children (median age: 2.7 years; range: birth to 18 years). Most central venous lines (97%) were located in the jugular veins. The overall incidence of deep venous thrombosis was 25 cases (28%) among 90 children. Venography identified deep venous thrombosis located in the subclavian and central veins but missed most deep venous thrombosis in the jugular veins. Venous ultrasonography had good sensitivity in the jugular veins but did not detect deep venous thrombosis in central veins. Echocardiography detected only 1 case of central deep venous thrombosis. CONCLUSIONS: The incidence of central venous line-related deep venous thrombosis in children with short-term central venous lines is high and comparable to reports for children with long-term central venous lines. Sensitivities of venography, venous ultrasonography, and echocardiography in children vary depending on the affected venous segment. A combination of diagnostic tests is required for sensitive detection of central venous line-related deep venous thrombosis in the upper venous system.