BackgroundVenous thromboembolism (VTE) is a relatively rare condition in childhood with treatment mainly based on extrapolation from studies in adults. Therefore, clinical trials of anticoagulation in children require novel approaches to deal with numerous challenges. The EINSTEIN-Jr program identified pediatric rivaroxaban regimens commencing with in vitro dose finding studies followed by evaluation of children of different ages through phase I and II studies using extensive modeling to determine bodyweight-related doses. Use of this approach resulted in drug exposure similar to that observed in young adults treated with rivaroxaban 20 mg once-daily.MethodsEINSTEIN-Jr phase III is a randomized, open-label, study comparing the efficacy and safety of rivaroxaban 20 mg-equivalent dose regimens with those of standard anticoagulation for the treatment of any types of acute VTE in children aged 0–18 years.A total of approximately 500 children are expected to be included during the 4-year study window. Flexibility of treatment duration is allowed with study treatment to be given for 3 months with the option to continue treatment in 3-month increments, up to a total of 12 months. However, based on most common current practice, children younger than 2 years with catheter-related thrombosis will have a main treatment period of 1 month with the option to prolong treatment in 1-month increments, up to a total of 3 months.ConclusionsEINSTEIN-Jr will compare previously established 20 mg-equivalent rivaroxaban dosing regimens with standard anticoagulation for the treatment of VTE in children. Demonstration of similarity of disease, as well as equivalent rivaroxaban exposure and exposure-response will enable extrapolation of efficacy from adult trials, which is critical given the challenges of enrollment in pediatric anticoagulation trials.Trial registrationClinicaltrials.gov NCT02234843, registered on 9 September 2014.

SummaryClassical homocystinuria due to cystathionine beta-synthase deficiency is one of the disorders revealing a high risk of thromboembolic events and vascular disease. This autosomal-recessively inherited metabolic disorder is considered to be rare with an estimated prevalence of 1:130,000 in the German population. In this study, we developed a novel multiplex PCR generating allele specific fragment lengths to analyse individual genotypes of the two most frequent cystathionine beta-synthase alterations, the I278T mutation, which is worldwide found on up to the half of homocystinuric alleles, and the adjacent polymorphism 844ins68. Screening of 200 unrelated German control subjects revealed a frequency of heterozygosity of 1.5% for I278T corresponding to a calculated frequency of homozygosity of 1:17.800. Our data indicate that homocystinuria due to cystathionine β-synthase deficiency is a frequently unrecognized disorder resulting in a high risk of thromboembolic events.

An open, prospective, randomized pilot study was performed to assess the efficacy and safety of oral fluconazole 3 mg/kg once daily compared with oral nystatin 50,000 units/kg/day in four divided doses in preventing candida infections in 50 children undergoing remission induction or consolidation therapy for cancer. In 21 of 25 fluconazole-treated and 20 of 25 nystatin-treated patients the overall outcome of prophylaxis was clearly successful. Mild and transient oropharyngeal candidosis was observed in two and three patients in the fluconazole and nystatin groups respectively. One patient randomized to fluconazole and two patients randomized to nystatin required empirical treatment with amphotericin B and one patient assigned to fluconazole developed tissue-proven candida colitis. Initially non-colonized patients remained yeast-free throughout treatment with no differences between the two study arms. Initially colonized patients stayed colonized throughout treatment although at the end of the study, more patients randomized to nystatin were still harbouring yeasts (P = 0.05). Almost exclusively, Candida albicans (95%) was isolated. A change in species was observed in one patient in each arm of the study. Candida krusei or Candida glabrata were not encountered. Transient elevations of hepatic transaminases were more common in the fluconazole group, although not statistically significant (28% vs 12%, P = 0.15). Reversible grade I gastrointestinal and skin symptoms were observed in four patients randomized to fluconazole (16 vs 0%, P < 0.05). Fluconazole was as safe and effective as nystatin in controlling yeast colonization and in preventing superficial and invasive candida infections and the empirical use of amphotericin B in children and adolescents undergoing intensive chemotherapy for cancer.

Aims The present study aims to characterise the genetic risk architecture of bicuspid aortic valve (BAV) disease, the most common congenital heart defect. Methods and results We carried out a genome-wide association study (GWAS) including 2,236 BAV patients and 11,604 controls. This led to the identification of a new risk locus for BAV on chromosome 3q29. The single nucleotide polymorphism (SNP) rs2550262 was genome-wide significant BAV-associated (P = 3.49 × 10−08) and was replicated in an independent case-control sample. The risk locus encodes a deleterious missense variant in MUC4 (p.Ala4821Ser), a gene that is involved in epithelial-to-mesenchymal transformation. Mechanistical studies in zebrafish revealed that loss of Muc4 led to a delay in cardiac valvular development suggesting that loss of MUC4 may also play a role in aortic valve malformation. The GWAS also confirmed previously reported BAV risk loci at PALMD (P = 3.97 × 10−16), GATA4 (P = 1.61 × 10−09), and TEX41 (P = 7.68 × 10−04). In addition, the genetic BAV architecture was examined beyond the single-marker level revealing that a substantial fraction of BAV heritability is polygenic and approximately 20% of the observed heritability can be explained by our GWAS data. Furthermore, we used the largest human single cell atlas for foetal gene expression and show that the transcriptome profile in endothelial cells is a major source contributing to BAV pathology. Conclusion Our study provides a deeper understanding of the genetic risk architecture of BAV formation on the single-marker and polygenic level.

atients with nonvalvular atrial fibrillation or venous thromboembolism require anticoagulation with a vitamin K antagonists (VKA) or direct oral anticoagulant (DOAC) in therapeutic doses (1-5). Metaanalyses of Phase III studies found that the efficacy of DOACs in preventing stroke or recurrent venous thrombosis was comparable to that of VKAs. Intracranial hemorrhage, fatal hemorrhage and clinically relevant non-severe hemorrhage occurred significantly less frequently in DOAC-treated patients compared to VKAtreated patients, while gastrointestinal hemorrhage was Summary Background: Few data have been published to date on outcomes after the common clinical experience of severe hemorrhage in orally anticoagulated patients. Methods: A prospective, multicenter observational study was carried out to investigate outcomes and management in a series of consecutive patients who sustained a severe hemorrhage under treatment with vitamin K antagonists (VKA) or direct oral anticoagulant drugs (DOAC). The primary endpoint was in-hospital death up to and including day 30 after hospital admission. The secondary endpoints were the duration of bleeding, in-hospital death due to hemorrhage (as defined by the study physician examining the patient's records), the use of antagonists, the extent of supportive measures used to stop the hemorrhage, and an assessment of causality. Consecutive patients were recruited until a predefined number of patients was reached in both groups. Results: Among 193 patients with severe hemorrhage, 97 had been taking a VKA, and 96 had been taking a DOAC. 13.0 % (95% confidence interval [8.6; 18.5]; 25/193) of the overall group patients died in the first 30 days after hospital admission, including 17.5% ([10.6; 26.6]; 17/97) in the VKA group and 8.3% ([3.7; 15.8]; 8/96) in the DOAC group (p = 0.085). The median duration of bleeding was 19.8 hours in the VKA group and 27.8 hours in the DOAC group (p = 0.632). The in-hospital mortality due to hemorrhage was higher in the VKA group than in the DOAC group (15.5% [15/97] versus 4.2% [4/97]; p = 0.014). Only the use of prothrombin complex concentrates (PCCs) lowered the median duration of hemorrhage in the two patient groups. In 35% (68/193) of the patients, the hemorrhage was caused by an external influence, most commonly a fall. Conclusion: The in-hospital mortality was higher among patients treated with VKA than among patients treated with DOAC, although the difference failed to reach statistical significance.