Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

Clinical Course and Visual Outcomes of Papilledema in Pediatric Cerebral Venous Sinus Thrombosis

PURPOSE

Cerebral venous sinus thrombosis (CVST) is a rare but life-threatening event with significant neurologic and visual morbidity. In this study, we report on the natural history and visual outcomes of papilledema in children with CVST.

DESIGN

Retrospective case series.

METHODS

Patients with CVST evaluated by the Department of Ophthalmology between 2000 and 2023 were included. Records were reviewed for presence and course of papilledema, treatment, and final visual outcomes following papilledema resolution.

RESULTS

The study included 35 patients with a mean age of 9 ± 5 years and 40% were female. The most common risk factors for CVST were infection (69%), dehydration (26%), and hypercoagulability (23%). 31 patients (89%) had papilledema. Of these patients, 9 (29%) had progression of papilledema despite treatment, 17 patients (55%) did not have progression, and 5 patients (16%) lacked follow-up records. Initial Frisén grade among all cases was 2 ± 1, and cases with progression reached a grade of 4 ± 1 between 10 and 32 days following initial identification. Most patients (97%) were treated with anticoagulation and 100% required acetazolamide and/or lumbar puncture. Among 26 patients with follow-up, papilledema resolved in 107 ± 128 days. Fifty-four percent of patients had permanent ophthalmic sequelae. An initial Frisén grade ≥3 (odds ratio 7.54, 95% confidence interval 6.53-8.70, P< .001) was significantly associated with eventual optic atrophy.

CONCLUSIONS

Children with CVST are at high risk for ophthalmologic sequelae. Papilledema can progress despite appropriate therapy. Our results highlight the importance of ophthalmologic follow-up during treatment course to prevent irreversible vision loss.

Pediatric splenic infarction: Assessment of associated clinical conditions and outcome

Pediatric splenic infarction (SI) is rare yet clinically significant. Publications regarding this complication are mostly limited to case reports. This is a retrospective study examining SI etiology, clinical presentation, management, and outcomes among children. Twenty-two patients (median age: 7.9 years) were included, mostly with pre-existing hematological diseases. Splenomegaly (72%), thrombocytopenia, and anemia were common. Most of the patients did not receive antithrombotic therapy yet only two patients experienced recurrences. During follow up 36% of patients died, however no fatalities were attributed to thrombotic or bleeding complications.

Patent Foramen Ovale in Children: A Review of Recent Progress

The support has been provided by clinical trials and guidelines for managing patent foramen ovale (PFO) in adults; however, the optimal approach is still unclear for treating PFO in pediatric patients. PFO and its associated clinical syndromes, imaging diagnosis, and management in pediatric patients were analyzed by a comprehensive analysis. Extensive research was performed using electronic databases, including PubMed, Cochrane, Web of Science, and EMBASE. This review includes the studies published until February 1st, 2024. A total of 583 articles were obtained, of which 54 were included in the comprehensive review. Numerous evidences have indicated that a right-to-left shunt through a PFO may be involved in cryptogenic stroke in children, although the connection between migraine and aura has not been substantiated by robust evidence. Children with sickle cell disease and a PFO were at higher risks of paradoxical embolization, rare syndromes caused by PFO could also occur in children such as platypnea-orthodeoxia syndrome, myocardial infarction, and decompression sickness. Contrast transthoracic echocardiography was deemed the most appropriate examination for children due to its favorable transthoracic windows, eliminating the need for anesthesia. This review suggested that the additional treatment was not needed as no evidence was provided for potential future complications linked to isolated PFO in children. For children facing unique circumstances related to PFO, a customized interdisciplinary consultation is essential prior to considering medical interventions.

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

The Effects of Aspirin dose in Children with Congenital and Acquired Heart Disease. Results from the Paediatric Study of Aspirin Efficacy using Diagnostic and Monitoring Tools (PAED-M)

The optimal dose of aspirin required in children with congenital and acquired heart disease is not known. The primary aim of this prospective observational study was to evaluate the effects of aspirin dose on platelet inhibition. The secondary aim was to determine the prevalence and clinical predictors of aspirin non-responsiveness. Measurements were by Thromboelastography with Platelet Mapping (TEGPM) only in children less than 2 years (y) of age with particular emphasis on the parameter known as maximum amplitude with arachidonic acid (MAAA) and using both TEGPM, and light transmission aggregometry (LTA) in children greater than 2 y. We prospectively studied 101 patients with congenital and acquired cardiac disease who were receiving empirical doses of aspirin for a minimum of 4 weeks but no other antiplatelet agents. Patients were stratified according to dose concentration and age. There was a trend toward lower age in patients with no response or semi-response to aspirin. All patients were considered responsive to aspirin in the higher-dose quartile (Q4) with a median dose of 4.72 (4.18-6.05) mg/kg/day suggesting that patients in this age group may require 5 mg/kg/day as an empirical dose. In children > 2 y, there was no significant difference in inhibition found in patients dosed at higher doses in Q3 versus Q4 suggesting that patients in this cohort are responsive with 3 mg/kg/day dose. The current practices may lead to reduced platelet inhibition in some children due to under-dosing or overdosing in others. In conclusion, younger children require higher doses of aspirin. Laboratory assessment is warranted in this population to mitigate against under and overdosing.

Uncovering Risk Factors and Outcomes of Pulmonary Embolism in a Nationwide Cohort of Hospitalized Children

PURPOSE

The incidence of pulmonary embolism (PE) in hospitalized children has increased in recent years. This study sought to characterize factors and outcomes associated with PE using a national pediatric cohort.

METHODS

The Nationwide Readmissions Database was queried (2016-2018) for patients (<18 years) with a diagnosis of PE. Index and prior hospitalizations (PHs) within 1 year were analyzed. A binary logistic regression utilizing 37 covariates (demographics, procedures, comorbidities, etc.) was constructed to examine a primary outcome of in-hospital mortality.

RESULTS

3440 patients were identified (57% female) with the majority >12 years old (77%). One-third had a known deep vein thrombosis (69% lower and 31% upper extremity). Nineteen percent underwent central venous catheter (CVC) placement. Twenty-one percent had a PH within 1 year. Nine percent underwent an operation with the majority being cardiothoracic (5%). Overall mortality was 5%. Neurocranial surgery, cardiothoracic surgery, and CVC placement were associated with the highest odds of inpatient mortality after logistic regression.

CONCLUSION

Pediatric patients with PE have a high rate of PHs, CVC placement, and inpatient operations, which may be associated with higher mortality. This information can be utilized to improve screening measures and clinical suspicion for PE in hospitalized children.

Treatment of multisystem inflammatory syndrome in children

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), a relatively uncommon but severe pediatric complication, is associated with coronavirus disease 2019 (COVID-19). A variety of treatment approaches, including intravenous immunoglobulins (IVIGs), glucocorticoids (GCs) and biologic agents, such as anakinra and infliximab, have been described for the management of COVID-19-related MIS-C. Anticoagulant therapy is also important. However, a well-developed treatment system has not been established, and many issues remain controversial. Several recently published articles related to the treatment of MIS-C have been released. Hence, in this review, we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and systematically.

DATA SOURCES

We reviewed the literature on the treatment of MIS-C through 20 September 2023. The PubMed/Medline, Web of Science, EMBASE, and Cochrane Library databases were searched with the combination of the terms "multisystem inflammatory syndrome", "MIS-C", "PIMS-TS", "therapy", "treatment", "drug", "IVIG", "GCs", "intravenous immunoglobulin", "corticosteroids", "biological agent", and "aspirin".

RESULTS

The severity of MIS-C varies, and different treatment schemes should be used according to the specific condition. Ongoing research and data collection are vital to better understand the pathophysiology and optimal management of MIS-C.

CONCLUSIONS

MIS-C is a disease involving multiple systems and has great heterogeneity. With the accumulation of additional experience, we have garnered fresh insights into its treatment strategies. However, there remains a critical need for greater standardization in treatment protocols, alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols. Supplementary file1 (MP4 208044 kb).

Evaluation of the Safety and Efficacy of Enoxaparin Once-Daily Versus Twice-Daily Dosing for Prophylaxis in Pediatric Patients

OBJECTIVES

Enoxaparin for the prevention of venous thromboembolism (VTE) in pediatric patients is -typically dosed twice a day. The use of once-daily dosing like that used in adult patients is limited because of a lack of safety and efficacy data. The aim of this study was to evaluate the safety and efficacy of -once-daily versus twice-daily dosing of enoxaparin for pediatric VTE prophylaxis based on incidence of thrombotic and bleeding events.

METHODS

This was a 3-year retrospective chart review of enoxaparin received for VTE prophylaxis at -Cohen Children's Medical Center, New Hyde Park, NY. Exclusion criteria were age 18 years or older, and renal dysfunction.

RESULTS

A total of 177 enoxaparin courses (81 in the once-daily and 96 in the twice-daily group) were included. The median dose in the once-daily group was 0.68 mg/kg/dose with dose capping at 40 mg/dose in 70% of patients. One patient in the once-daily group had a VTE, whereas no patients in the twice-daily group experienced a VTE. One major bleeding event occurred in the once-daily group (p = 0.46); however, minor bleeding events were comparable between the 2 groups (p = 0.69).

CONCLUSIONS

Once-daily enoxaparin prophylaxis appears to be safe and effective based on minimal -differences in incidence of thrombotic and bleeding events when compared to twice-daily dosing. Based on this study, it may be reasonable to consider once-daily enoxaparin dosing for prophylaxis, especially in older children. A larger multicenter cohort study evaluating once-daily dosing for prophylaxis is warranted to validate the safety and efficacy specifically for risk-based dosing strategies.

Being precise with anticoagulation to reduce adverse drug reactions: are we there yet?

Anticoagulants are potent therapeutics widely used in medical and surgical settings, and the amount spent on anticoagulation is rising. Although warfarin remains a widely prescribed oral anticoagulant, prescriptions of direct oral anticoagulants (DOACs) have increased rapidly. Heparin-based parenteral anticoagulants include both unfractionated and low molecular weight heparins (LMWHs). In clinical practice, anticoagulants are generally well tolerated, although interindividual variability in response is apparent. This variability in anticoagulant response can lead to serious incident thrombosis, haemorrhage and off-target adverse reactions such as heparin-induced thrombocytopaenia (HIT). This review seeks to highlight the genetic, environmental and clinical factors associated with variability in anticoagulant response, and review the current evidence base for tailoring the drug, dose, and/or monitoring decisions to identified patient subgroups to improve anticoagulant safety. Areas that would benefit from further research are also identified. Validated variants in VKORC1, CYP2C9 and CYP4F2 constitute biomarkers for differential warfarin response and genotype-informed warfarin dosing has been shown to reduce adverse clinical events. Polymorphisms in CES1 appear relevant to dabigatran exposure but the genetic studies focusing on clinical outcomes such as bleeding are sparse. The influence of body weight on LMWH response merits further attention, as does the relationship between anti-Xa levels and clinical outcomes. Ultimately, safe and effective anticoagulation requires both a deeper parsing of factors contributing to variable response, and further prospective studies to determine optimal therapeutic strategies in identified higher risk subgroups.

Anticoagulation of pediatric patients with venous thromboembolism in 2023

Venous thromboembolism (VTE) is a rare and heterozygous disease in children. Management of VTE in children is complicated by age-related differences in epidemiology, recurrent VTE and bleeding risk, hemostatic proteins and pharmacokinetics of anticoagulants. Recently, the choice of anticoagulation has expanded to oral factor IIa and Xa inhibitors, which have been authorized for children for treatment of acute VTE and extended secondary prevention. These drugs have several properties that make them extremely suitable for use in children, including oral administration, antithrombin independence, less interactions with food and drugs and no need for monitoring. Unfortunately, the phase 3 studies had many exclusion criteria, and only a few term neonates and infants were included in these studies. Additional real-world data is needed to make evidence-based recommendations in these age and patient groups, as well.

Analysis of Platelet Function Testing in Children Receiving Aspirin for Antiplatelet Effects

Aspirin (ASA) remains the most common antiplatelet agent used in children. VerifyNow Aspirin Test® (VN) assesses platelet response to ASA, with therapeutic effect defined by the manufacturer as ≤ 549 aspirin reaction units (ARU). Single-center, observational, analysis of 195 children (< 18 years-old) who underwent first VN between 2015 and 2020. Primary outcome was proportion of patients with ASA biochemical resistance (> 549 ARU). Secondary outcomes included incidence of new clinical thrombotic and bleeding events during ≤ 6 months from VN in those who received ASA monotherapy (n = 113). Median age was 1.8 years. Common indications for ASA included cardiac anomalies or dysfunction (74.8%) and ischemic stroke (22.6%). Median ASA dose before VN was 4.6 mg/kg/day. Mean VN was 471 ARU. ASA biochemical resistance was detected in 14.4% (n = 28). Of 113 patients receiving ASA monotherapy, 14 (12.4%) had a thrombotic event and 2 (1.8%) had a bleeding event. Mean VN was significantly higher at initial testing in patients experiencing thrombotic event compared to those without thrombosis (516 vs 465 ARU, [95% CI: 9.8, 92.2], p = 0.02). Multivariable analysis identified initial VN ASA result ≥ 500 ARU at initial testing as the only significant independent risk factor for thrombosis (p < 0.01). VN testing identifies ASA biochemical resistance in 14.4% of children. VN ASA ≥ 500 ARU rather than ≥ 550 ARU at initial testing was independently associated with increased odds of thrombosis. Designated cut-off of 550 ARU for detecting platelet dysfunction by ASA may need reconsideration in children.

Utility of a pharmacist-managed Anticoagulation Program in patients with congenital heart disease

BACKGROUND

Warfarin remains the preferred anticoagulant for many patients with CHD. The complexity of management led our centre to shift from a nurse-physician-managed model with many providers to a pharmacist-managed model with a centralized anticoagulation team. We aim to describe the patient cohort managed by our Anticoagulation Program and evaluate the impact of implementation of this consistent, pharmacist-managed model on time in therapeutic range, an evidence-based marker for clinical outcomes.

METHODS

A single-centre retrospective cohort study was conducted to evaluate the impact of the transition to a pharmacist-managed model to improve anticoagulation management at a tertiary pediatric heart centre. The percent time in therapeutic range for a cohort managed by both models was compared using a paired t-test. Patient characteristics and time in therapeutic range of the program were also described.

RESULTS

After implementing the pharmacist-managed model, the time in therapeutic range for a cohort of 58 patients increased from 65.7 to 80.2% (p < .001), and our Anticoagulation Program consistently maintained this improvement from 2013 to 2022. The cohort of patients managed by the Anticoagulation Program in 2022 included 119 patients with a median age of 24 years (range 19 months-69 years) with the most common indication for warfarin being mechanical valve replacement (n = 81, 68%).

CONCLUSIONS

Through a practice change incorporating a collaborative, centralized, pharmacist-managed model, this cohort of CHD patients on warfarin had a fifteen percent increase in time in therapeutic range, which was sustained for nine years.

How I treat pediatric venous thromboembolism in the DOAC era

ABSTRACT

The direct oral anticoagulants (DOACs) rivaroxaban and dabigatran are newly licensed for the treatment and prevention of venous thromboembolism (VTE) in children and mark a renaissance in pediatric anticoagulation management. They provide a convenient option over standard-of-care anticoagulants (heparins, fondaparinux, and vitamin K antagonists) because of their oral route of administration, child-friendly formulations, and significant reduction in monitoring. However, limitations related to therapeutic monitoring when needed and the lack of approved reversal agents for DOACs in children raise some safety concerns. There is accumulating experience of safety and efficacy of DOACs in adults for a broad scope of indications; however, the cumulative experience of using DOACs in pediatrics, specifically for those with coexisting chronic illnesses, is sparse. Consequently, clinicians must often rely on their experience for treating VTE and extrapolate from data in adults while using DOACs in children. In this article, the authors share their experience of managing 4 scenarios that hematologists are likely to encounter in their day-to-day practice. Topics addressed include (1) appropriateness of indication; (2) use for special populations of children; (3) considerations for laboratory monitoring; (4) transition between anticoagulants; (5) major drug interactions; (6) perioperative management; and (7) anticoagulation reversal.

Is the current therapeutic dosage of nadroparin adequate for neonates and infants under 8 months with thromboembolic disease? a population pharmacokinetic study from a national children's medical center

Objectives: Nadroparin, a low-molecular-weight-heparin is commonly used off-label in neonates and infants for thromboembolic events prevention. However, the recommended dosing regimen often fails to achieve therapeutic target ranges. This study aimed to develop a population pharmacokinetic (PK) model of nadroparin to determine an appropriate dosing regimen for neonates and infants less than 8 months. Methods: A retrospective chart review was conducted on patients treated with nadroparin at Children's Hospital of Fudan University between July 2021 and December 2023. A population PK model was developed using anti-Xa levels, and its predictive performance was evaluated internally. Monte Carlo simulations were performed to design an initial dosing schedule targeting anti-Xa levels between 0.5 and 1 IU/mL. Results: A total of 40 neonates and infants aged less than 8 months with gestational age ranging from 25 to 41 weeks treated with nadroparin were enrolled in the study for analysis. A one-compartment PK model with first order absorption and elimination was adequately fitted to the data. Creatinine clearance was identified as a significant factor contributing to inter-individual variability in clearance. The typical population parameter estimates of clearance, distribution volume and absorption rate in this population were 0.211 L/h, 1.55 L and 0.495 h-1, respectively. Our findings suggest that current therapeutic doses of nadroparin (150-200 IU/kg q12 h) may result in subtherapeutic exposure, thus higher doses might be required. Conclusion: The present study offers the first estimation of PK parameters for nadroparin in preterm or term neonates and infants less than 8 months utilizing the model. Our findings have potential implications for recommending initial personalized dosages, particularly among patient populations exhibiting similar characteristics.

Venous Thromboembolism in Children: The Rivaroxaban Experience

The incidence of venous thromboembolism (VTE) in the pediatric population has increased more than 10-fold in the last 20 years, as a consequence of the advancement of resuscitation and surgical techniques and the global increase in life expectancy of children suffering from chronic pathologies. Monitoring anticoagulant therapy to achieve outcomes within the target range in childhood VTE, parenteral administration of medications, and frequent blood tests in children are often cumbersome. Availability of safe and effective oral agents with pediatric data to support use would be of clear benefit. A physiologically based pharmacokinetic model was developed to estimate the appropriate dosing schedule for rivaroxaban in children. This incorporated growth/maturation and variability in anthropometrics (e.g., body height, weight, and body mass index), anatomy (e.g., organ weight), physiology (e.g., blood flow rates), metabolism and excretion. Rivaroxaban use in pediatric population underwent a complete investigational program, consisting mainly of one phase I pharmacokinetics/pharmacodynamics trial, three phase II trials, one phase III trial. The phase III trial enrolled 500 patients from birth to <18 years and documented the efficacy and safety of rivaroxaban regimens at dose equivalent to the adult 20 mg dose for the prevention of fatal or symptomatic nonfatal recurrent VTE and major bleeding versus heparin or vitamin K antagonists. Results were similar to those in rivaroxaban studies in adults. The efficacy and safety of rivaroxaban in children reported in the EINSTEIN JUNIOR trial provide further support to previous trials in adults (EINSTEIN Program), which demonstrate a favorable profile for the use of rivaroxaban for the management of VTE in challenging patient populations. Other clinical evidence contributing to the use of rivaroxaban among different risk groups in pediatric VTE population confirms the consistency with principal trial. Our review aims to describe the rationale for using rivaroxaban oral suspension in clinical practice and to summarize its multiple indications in each vascular bed (e.g., cerebral venous thrombosis, symptomatic or asymptomatic central venous catheter-associated thrombosis), etiology, and patients setting.

The impact of child-specific characteristics on warfarin dosing requirements

Background

The influence of child characteristics on warfarin dosing has been reported; however, there is no consensus on the nature and extent of this effect.

Objectives

To investigate the impacts of the demographic and clinical characteristics of children on the warfarin dose required to achieve a therapeutic international normalization ratio (INR).

Methods

This retrospective cohort study included children aged 3 months to 14 years old who were prescribed warfarin for 3 months or longer with a "stable INR." The primary outcome was the total daily dose (TDD) and total weekly dose of warfarin required to achieve a therapeutic INR target.

Results

We included 127 patients with a mean age of 7.7 ± 3.7 years and a median weight of 22 (IQR, 16-33) kg. Of the sample, 55 patients (43.3%) required a TDD of ≤0.1 mg/kg. The TDD for children younger than 5 years, 5 to 10 years, and older than 10 years were 0.14 ± 0.06 mg/kg, 0.12 ± 0.05 mg/kg, and 0.096 ± 0.04 mg/kg, respectively (P = .002). Overweight and obese children required a smaller TDD than normal-weight children: 0.09 ± 0.05 vs 0.13 ± 0.05 mg/kg (P = .004), which was similar for underweight children. A lower body surface area (<0.5 m2) required a higher dose. All the other variables did not affect warfarin doses. The incidence of a subtherapeutic or supratherapeutic INR was independent of demographic or clinical variables.

Conclusion

The study confirmed that the patient demographics affect the daily warfarin dose required to achieve the INR target. However, they do not have any predictive value for the incidence of out-of-range-INR.

Pharmacokinetic Modeling Using Real-World Data to Optimize Unfractionated Heparin Dosing in Pediatric Patients on Extracorporeal Membrane Oxygenation and Evaluate Target Achievement-Clinical Outcomes Relationship

Unfractionated heparin (UFH) is a commonly used anticoagulant for pediatric patients undergoing extracorporeal membrane oxygenation (ECMO), but evidence is lacking on the ideal dosing. We aimed to (1) develop a population pharmacokinetic (PK) model for UFH, measured through anti-factor Xa assay; (2) optimize UFH starting infusions and dose titrations through simulations; and (3) explore UFH exposure-clinical outcomes relationship. Data from 218 patients admitted to Utah's Primary Children's Hospital were retrospectively collected. A 1-compartment PK model with time-varying clearance (CL) adequately described UFH PK. Weight on CL and volume of distribution and ECMO circuit change on CL were significant covariates. The typical estimates for initial CL and first-order rate constant to reach steady-state CL were 0.57 L/(h·10 kg) and 0.02/h. Comparable to non-ECMO patients, the typical steady-state CL was 0.81 L/(h·10 kg). Simulations showed that a 75 IU/kg UFH bolus dose followed by starting infusions of 25 and 20 IU/h/kg for patients aged younger than 6 years and 6 years or older, respectively, achieved the therapeutic target in 56.6% of all patients, whereas only 3.1% exceeded the target. The proposed UFH titration schemes achieved the target in more than 90% of patients while less than 0.63% were above the target after 24 and 48 hours of treatment. The median intensive care unit survival time in patients within and below the target at 24 hours was 136 and 66 hours, respectively. In conclusion, PK model of UFH was developed for pediatric patients on ECMO. The proposed UFH dosing scheme attained the anti-factor Xa target rapidly and safely.

Evaluation of Initial Enoxaparin Dosing and Antifactor Xa Levels in Infants Admitted to the Neonatal Intensive Care Unit

Introduction

Infants are at risk for thrombotic conditions due to multiple risk factors such as congenital heart defects and sepsis. According to the American College of Chest Physicians (ACCP) 2012 guidelines, enoxaparin may be given for thrombotic conditions at a dose of 1.5 mg/kg/dose every 12 h for patients less than 2 months of age and 1 mg/kg/dose every 12 h for those older than 2 months. Several studies have reported that infants typically require a higher initial dose of enoxaparin to reach therapeutic antifactor Xa levels than what is currently recommended.

Methods

This is a single-center retrospective case-control study of hospitalized infants less than 12 months of age who received treatment with enoxaparin while admitted to the neonatal intensive care unit (NICU) at a freestanding children's hospital. The primary objective was the difference between the initial enoxaparin dose (mg/kg) compared to the enoxaparin dose in which the patient first achieved a therapeutic antifactor Xa level of 0.5-1.0 units/mL.

Results

A total of 56 infants were included in this study. The median enoxaparin dose at initiation was 1.5 mg/kg/dose, and the median enoxaparin dose at the first therapeutic antifactor Xa level was 1.9 mg/kg/dose (z = -12.7, p < 0.0001). There was no correlation between gestational age and weight with the enoxaparin dose required to reach a therapeutic antifactor Xa level.

Conclusion

Infants admitted to the NICU, specifically those less than 4 months of age, require higher initial enoxaparin dosing to reach therapeutic antifactor Xa levels than what is currently recommended.

Efficacy and Safety of Direct Oral Anticoagulants in Pediatric Venous Thromboembolism: A Systematic Review and Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of direct oral anticoagulants (DOACs) in comparison to standard-of-care (SOC) anticoagulants in the management and prophylaxis of thromboembolic events in pediatric populations.

METHODS

A comprehensive search of electronic databases was conducted to identify relevant studies published between January 1, 2015, and December 18, 2022. A meta-analysis was undertaken to evaluate the effect of DOACs on clinically significant endpoints, employing trial-level data with harmonized endpoint definitions. The primary outcome was venous thromboembolism (VTE). Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The study was registered with INPLASY (2022120065).

RESULTS

Three studies encompassing 934 subjects were included. The incidence of VTE was reduced in patients administered DOACs compared to those on SOC anticoagulants (OR 0.41 [95% CI 0.19-0.93], I² = 0%, P = 0.03). No significant differences were observed between the DOAC and SOC groups in all-cause mortality (OR 0.50 [95% CI 0.07-3.59], I² = 0%, P = 0.35) or serious adverse events (OR 0.75 [95% CI 0.50-1.12], I² = 0%, P = 0.16). The risk of major bleeding (OR 0.50 [95% CI 0.13-1.87], I² = 44%, P = 0.30) and clinically relevant non-major bleeding (OR 1.23 [95% CI 0.50-3.00], I² = 0%, P = 0.65) exhibited no significant differences between the groups.

CONCLUSIONS

DOACs are associated with a reduced risk of VTE in pediatric patients without increasing the risk of bleeding, all-cause mortality, or serious adverse events when compared to SOC anticoagulants. DOACs may be an alternative for the treatment and prevention of thromboembolic events in the pediatrics.

Apixaban for Prevention of Thromboembolism in Pediatric Heart Disease

BACKGROUND

Children with heart disease frequently require anticoagulation for thromboprophylaxis. Current standard of care (SOC), vitamin K antagonists or low-molecular-weight heparin, has significant disadvantages.

OBJECTIVES

The authors sought to describe safety, pharmacokinetics (PK), pharmacodynamics, and efficacy of apixaban, an oral, direct factor Xa inhibitor, for prevention of thromboembolism in children with congenital or acquired heart disease.

METHODS

Phase 2, open-label trial in children (ages, 28 days to <18 years) with heart disease requiring thromboprophylaxis. Randomization 2:1 apixaban or SOC for 1 year with intention-to-treat analysis.

PRIMARY ENDPOINT

a composite of adjudicated major or clinically relevant nonmajor bleeding. Secondary endpoints: PK, pharmacodynamics, quality of life, and exploration of efficacy.

RESULTS

From 2017 to 2021, 192 participants were randomized, 129 apixaban and 63 SOC. Diagnoses included single ventricle (74%), Kawasaki disease (14%), and other heart disease (12%). One apixaban participant (0.8%) and 3 with SOC (4.8%) had major or clinically relevant nonmajor bleeding (% difference -4.0 [95% CI: -12.8 to 0.8]). Apixaban incidence rate for all bleeding events was nearly twice the rate of SOC (100.0 vs 58.2 per 100 person-years), driven by 12 participants with ≥4 minor bleeding events. No thromboembolic events or deaths occurred in either arm. Apixaban pediatric PK steady-state exposures were consistent with adult levels.

CONCLUSIONS

In this pediatric multinational, randomized trial, bleeding and thromboembolism were infrequent on apixaban and SOC. Apixaban PK data correlated well with adult trials that demonstrated efficacy. These results support the use of apixaban as an alternative to SOC for thromboprophylaxis in pediatric heart disease. (A Study of the Safety and Pharmacokinetics of Apixaban Versus Vitamin K Antagonist [VKA] or Low Molecular Weight Heparin [LMWH] in Pediatric Subjects With Congenital or Acquired Heart Disease Requiring Anticoagulation; NCT02981472).

Case report: One case of umbilical vein thrombosis in the second trimester with associated portal vein thrombosis after childbirth

Background

Umbilical vein thrombosis is a rare pregnancy complication, that is difficult to detect prenatally but can lead to poor fetal outcomes.

Case presentation

We described a 33-year-old primiparae who was identified as having umbilical vein thrombosis by ultrasound at 21 weeks gestation, and the neonate was found to have a portal vein thrombus after delivery. Following enoxaparin anticoagulant therapy, the thrombus disappeared within 4 weeks. No thrombus formation occured during the 10-month follow-up, and the baby was in excellent clinical condition.

Conclusion

Owing to the poor fetal outcomes related to umbilical thrombosis, pay attention to abnormal clinical signs during prenatal ultrasound, fetal heart monitoring and counting fetal movements can help in the early identification of umbilical cord thrombosis.The findings highlight the importance of regular prenatal ultrasound evaluation, enabling early detection and monitoring of any anomalies or vascular abnormalities related to the fetal umbilical vein. Further research is warranted to explore the clinical implications and long-term outcomes associated with these findings.

Acute management of childhood stroke

PURPOSE OF REVIEW

The purpose of this paper is to review recent updates in the acute management of childhood arterial ischemic stroke, including reperfusion therapies and neuroprotective measures.

RECENT FINDINGS

With the emergence of pediatric stroke centers in recent years, processes facilitating rapid diagnosis and treatment have resulted in improved implementation of early targeted neuroprotective measures as well as the increased use of reperfusion therapies in childhood arterial ischemic stroke. Retrospective data has demonstrated that alteplase is safe in carefully selected children with arterial ischemic stroke in the first 4.5 h from symptom onset, though data regarding its efficacy in children are still lacking. There is also increasing data that suggests that thrombectomy in children with large vessel occlusion improves functional outcomes. Recent adult studies, including the use of Tenecteplase as an alteplase alternative and expansion of late thrombectomy to include patients with large ischemic cores, also are reviewed along with limitations to application of the adult data to pediatric care.

SUMMARY

There have been significant advances in the hyperacute care of children with ischemic stroke and early diagnosis and targeted management are of the upmost importance in improving long-term outcomes.

Multimodality imaging in marantic endocarditis associated with cancer: a multicentric cohort study

AIMS

We aimed to assess the role of multimodality imaging (MMI) in the diagnosis of marantic endocarditis (ME) associated with cancers and to describe the clinical characteristics, management, and outcome of these patients.

METHODS AND RESULTS

In a retrospective multicentric study including four tertiary centres for the treatment of endocarditis in France and Belgium, patients with a diagnosis of ME were included. Demographic, MMI [echocardiography, computed tomography (CT), and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)], and management data were collected. Long-term mortality was analysed. Between November 2011 and August 2021, 47 patients with a diagnosis of ME were included. Mean age was 65 ± 11 years. ME occurred in 43 cases (91%) on native valves. Vegetations were detected by echocardiography in all cases and in 12 cases (26%) by CT. No patient had an increased cardiac 18F-FDG valve uptake. The most common cardiac valve involved was aortic (34 cases, 73%). Twenty-two patients (46%) had a known cancer before ME, and 25 cases (54%) were diagnosed thanks to multimodality imaging. 18FDG PET/CT was performed in 30 patients (64%) and allowed a new diagnosis of cancer in 14 patients (30%). Systemic embolism was frequent (40 patients, 85% of cases). Forty-one patients (87%) were treated medically with anticoagulation therapy. One-year mortality was 55% (26 patients).

CONCLUSION

ME remains associated with a high risk of complications and death.

Novel Dosing and Monitoring of Aspirin in Infants With Systemic-to-Pulmonary Artery Shunt Physiology: the SOPRANO Study

OBJECTIVES

Provision of pulmonary blood flow with a systemic-to-pulmonary artery shunt is essential in some patients with cyanotic congenital heart disease. Traditionally, aspirin (ASA) has been used to prevent thrombosis. We evaluated ASA dosing with 2 separate antiplatelet monitoring tests for accuracy and reliability.

METHODS

This is a retrospective, pre-post intervention single center study. Two cohorts were evaluated; the pre-intervention group used thromboelastography platelet mapping (TPM) and post-intervention used VerifyNow aspirin reactivity unit (ARU) monitoring. The primary endpoint was to compare therapeutic effect of TPM and ARU with regard to platelet inhibition. Inadequate platelet inhibition was defined as TPM <50% inhibition and ARU >550.

RESULTS

Data from 49 patients were analyzed: 25 in the TPM group and 24 in the ARU group. Baseline characteristics were similar amongst the cohorts. The TPM group had significantly more patients with inadequate platelet inhibition (14 [56%] vs 2 [8%]; p = 0.0006) and required escalation with additional thromboprophylaxis (15 [60%] vs 5 [21%]). There was no difference in shunt thrombosis (1 [2%] vs 0 [0%]; p = 0.32), cyanosis requiring early re-intervention (9 [36%] vs 14 [58%]; p = 0.11), or bleeding (15 [60%] vs 14 [58%]; p = 0.66).

CONCLUSION

With similar cohorts and the same ASA-dosing nomogram, ARU monitoring resulted in a reduced need for escalation of care and concomitant thromboprophylaxis with no difference in adverse outcomes. Our study suggests ARU monitoring compared with TPM may be a more reliable therapeutic platelet inhibition test for determining ASA sensitivity in children with congenital heart disease requiring systemic-to-pulmonary artery shunt.

Nomogram for Predicting Long-term Outcomes of Encephaloduroarteriosynangiosis in Toddlers with Moyamoya Disease: a Longitudinal and Cross-sectional Study

We investigated the long-term outcomes of encephaloduroarteriosynangiosis (EDAS) for stroke prevention in toddlers with moyamoya disease (MMD) using nomogram. Between January 2005 and December 2018, 74 toddlers with MMD underwent surgery in the Fifth Medical Centre, Chinese PLA General Hospital, 69 were < 4 years of age and included in the analysis. The modified Rankin scale (mRS) during follow-up evaluated clinical outcomes. To measure the effectiveness of EDAS, the annual risk of symptomatic infarction within the operated brain hemispheres was calculated. The event-free survival rate was determined using Kaplan-Meier curves. A nomogram generated using multivariate logistic regression analysis identified potential predictors associated with unfavorable outcomes. Additionally, discrimination, calibration, and clinical utility were assessed. A favorable clinical outcome was observed in 81.2% of the patients. The operated hemispheres showed an annual risk of 0.87% of symptomatic infarction and 0.23% of hemorrhage. Moreover, the 10-year event-free survival rates were 92.8% and 97.0% for symptomatic infarction and hemorrhage. Multivariate logistic analysis indicated that onset with infarction, initial mRS ≥ 3, and perioperative adverse events had significant and independent associations with unfavorable outcomes. However, an age at diagnosis of ≥ 2 years showed an association with favorable outcomes. Using these four factors, our model attained a concordance index of 0.912 (95% confidence interval, 0.842-0.982), well-fitted calibration curve, and cutoff value of 0.212 for predicting unfavorable outcomes. EDAS may prevent recurrent stroke and improve overall long-term clinical outcomes in toddlers with MMD. The developed nomogram accurately predicted unfavorable outcomes and assisted surgeons in patient evaluation.

An Evaluation of the Appropriateness of Initial Enoxaparin Dosing Among Pediatric Patients

Background Enoxaparin is a low molecular weight heparin that irreversibly inactivates factor Xa leading to the inhibition of clot formation. Despite the non-FDA approval in pediatrics, enoxaparin is recommended with an initial dose of 1.5mg/kg/q12hrs for patients aged ≤ 2 months and 1mg/kg/q12hrs for patients > 2 months, targeting therapeutic anti-Xa with a range of 0.5 to 1 units/mL. Due to more rapid clearance in pediatrics, our study aims to assess the need for initial higher doses than recommended by the guideline to reach the target anti-Xa level. Methods A retrospective chart review of all pediatric patients under all specialties who were treated with enoxaparin either in inpatient or outpatient settings between February 2021 and June 2022 at children's specialized hospital and meet the inclusion criteria, including age ≤ 15 years old and treated with enoxaparin with initial dose according to the American College of Chest Physicians (CHEST) guideline, while patients who received prophylaxis doses did not have anti-Xa levels or creatinine clearance < 30 mL/min/1.73m2 were excluded. Demographic data, laboratory data, and enoxaparin dosing were all collected to assess whether the initial enoxaparin dose will result in a therapeutic level as a primary endpoint and secondary endpoints including the average enoxaparin dose required to achieve the therapeutic level and to report any side effects. All data were entered and analyzed using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25, Armonk, NY), and all categorical variables were reported as frequency and percentage while continuous variables expressed as mean ± SD and the study was approved by our research center institutional review board (IRB). Results Thirty patients were included in the study (17 males), 10 patients were aged ≤ 2 months, four were between 3 and 12 months and 16 were > 12 months, most of the patients received enoxaparin for deep vein thrombosis. In the majority of patients (76.7%), the initial dose failed to achieve the target anti-Xa while a mean dose of 2 mg/kg/q12hrs in patients ≤ 2 months, 1.7mg/kg/q12hrs in patients 3-12 months and 1.3 mg/kg/q12hrs in patients > 12 months was sufficient to reach the target level. After achieving a therapeutic anti-Xa level, only one patient experienced major bleeding while four patients experienced minor bleeding, no edema or thrombocytopenia were reported. Conclusion In conclusion, initiating enoxaparin according to the recommended dose by the guideline failed to achieve target anti-Xa in the majority of patients which necessitates starting enoxaparin with initial higher doses according to the patient's age to provide more prompt achievement of target anti-Xa.

Guiding warfarin self-management in children: development of a warfarin nomogram

Background

Warfarin therapy in children is impacted by many variables. To support the implementation of a self-management program within a pediatric anticoagulation service, a pediatric-specific warfarin nomogram was needed. A literature review revealed no published pediatric nomograms; therefore, a nomogram was developed drawing upon an evidence-based "Warfarin Information for Clinicians" hospital guideline.

Objectives

This study aimed to evaluate the suitability of a pediatric warfarin nomogram.

Methods

A retrospective audit of electronic medical records compared the dosing and international normalized ratio (INR) retest decisions made by hematology clinicians to the dosing and retesting recommended by a new warfarin nomogram at a pediatric hospital. Children (aged 6 months-18 years) receiving warfarin therapy for >6 months were included. Data were collected between September 2019 and February 2020. Descriptive data analysis was performed. The study was approved by the hospital's Human Research Ethics Committee.

Results

Warfarin dosing and INR retest decisions for 39 children were included, equating to 521 INRs. The nomogram matched 81.4% of clinicians dosing decisions and 30% of INR retest decisions. Moreover, 59% of the clinician-recommended retest dates were earlier than the nomogram recommendation. In the INR 2.0-3.0 group, 84.4% of dosing decisions and 72% of retest decisions matched the nomogram.

Conclusions

These results suggest that this pediatric nomogram is a suitable tool for warfarin dosing, as recommended warfarin doses matched the majority of clinicians' decisions. Modification may be needed to nomogram recommendations for the time to retest. This nomogram can be used to support warfarin self-management and may assist clinicians and patients or families in making evidence-based dosing decisions.

[Illustrated case study of a patient with pediatric multisystem inflammatory syndrome]

Between November 2020 and June 2021, twelve children were treated at a university hospital in western France for pediatric multisystem inflammatory syndrome (PIMS). While the clinical presentation may have been reminiscent of Kawasaki disease, PIMS, a new nosological entity, was mentioned in the media in the context of the Covid-19 pandemic. In 2023, research into this syndrome will continue in France and Europe.

Perinatal Stroke in a Chinese Neonatal Center: Clinical Characteristics, Long-Term Outcomes, and Prognostic Factors

BACKGROUND

Neonatal stroke manifests atypically and can potentially result in significant neurological sequelae in affected infants. Studies on long-term neurodevelopmental outcomes and prognostic factors are limited. We aimed to assess the clinical characteristics, long-term outcomes, and prognostic factors of perinatal stroke.

METHODS

Patients diagnosed with perinatal stroke were enrolled from 2009 to 2018. Clinical data including general information, clinical manifestations, and risk factors were collected and compared. Follow-up was performed for at least two years. Statistical analysis was performed using the chi-square test, t tests, and logistic regression analysis.

RESULTS

Sixty-nine cases were identified with an incidence of one of 2049 live births (51 boys and 18 girls). Twenty-seven patients (39%) experienced perinatal ischemic stroke (PIS) and 42 (61%) perinatal hemorrhagic stroke (PHS). In 48 cases (69%) onset involved acute symptomatic stroke (21 ischemic strokes and 27 hemorrhagic strokes). Seizures within 12 to 72 hours (20 cases, 29%) were the most common presentations. Most (57%) perinatal arterial ischemic strokes focused on the left middle cerebral artery. About 43% of PHS was diagnosed with temporal lobe hemorrhage, and 40% of patients exhibited multiple lesions of cerebral parenchymal hemorrhage. There was no association between adverse prognosis after perinatal stroke and different risk factors. During follow-up, six patients (10%) were dead and 22 patients (35%) experienced adverse neurodevelopmental outcomes.

CONCLUSIONS

More infants exhibited hemorrhagic stroke than ischemic stroke. Among infants with asymptomatic perinatal stroke, PHS was more common. The first symptom of perinatal stroke within 12 to 72 hours after birth is convulsions, with the left middle cerebral artery and the temporal lobe being the most common lesion sites for ischemic and hemorrhagic strokes, respectively. PIS was more likely to achieve adverse outcomes.

Anti-factor Xa level monitoring of low-molecular-weight heparin for prevention of venous thromboembolism in critically ill patients (AXaLPE): protocol of a randomised, open-label controlled clinical trial

INTRODUCTION

Whether and when to monitor the amount of anti-factor Xa (aFXa) activity in critically ill patients with complex diseases to prevent venous thromboembolism (VTE) remain unclear. This study is a randomised controlled trial to investigate the effect of aFXa level monitoring on reducing VTE and to establish a new method for accurately preventing VTE in critically ill patients with low-molecular-weight heparin (LMWH).

METHODS AND ANALYSIS

A randomised controlled trial is planned in two centres with a planned sample size of 858 participants. Participants will be randomly assigned to three groups receiving LMWH prophylaxis at a 1:1:1 ratio: in group A, peak aFXa levels will serve as the guide for the LMWH dose; in group B, the trough aFXa levels will serve as the guide for the LMWH dose; and in group C, participants serving as the control group will receive a fixed dose of LMWH. The peak and trough aFXa levels will be monitored after LMWH (enoxaparin, 40 mg, once daily) reaches a steady state for at least 3 days. The monitoring range for group A's aFXa peak value will be 0.3-0.5 IU/mL, between 0.1 and 0.2 IU/mL is the target range for group B's aFXa trough value. In order to reach the peak or trough aFXa levels, groups A and B will be modified in accordance with the monitoring peak and trough aFXa level. The incidence of VTE will serve as the study's primary outcome indicator. An analysis using the intention-to-treat and per-protocol criterion will serve as the main outcome measurement.

ETHICS AND DISSEMINATION

The Xuanwu Hospital Ethics Committee of Capital Medical University and Peking University First Hospital Ethics Committee have approved this investigation. It will be released in all available worldwide, open-access, peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05382481.

Right femoral vein and right dorsal artery thrombosis in childhood acute myeloid leukemia: A case report

BACKGROUND

It is rare for newly diagnosed (de novo) or newly treated acute myeloid leukemia (AML) complicated with thrombotic complications, especially combined arterial and venous thrombosis.

METHODS

We reported a 13-year-old boy diagnosed with AML and leukocytosis, who developed right femoral vein and right dorsal artery thrombosis during chemotherapy. After treatment with low molecular weight heparin, diosmin, and alprostadil, symptoms were relieved. Unfortunately, the child suffered from coagulopathy afterward, which was unexpectedly caused by vitamin K deficiency.

RESULTS

After supplementation with vitamin K and prothrombin complex concentrate, coagulation function recovered.

CONCLUSION

For childhood AML patients with high thrombotic risks, close monitoring during anticoagulant treatment was necessary. Concomitantly, we should be alert to past medication history and combined medication use, especially those that may lead to vitamin K deficiency, secondary bleeding, and coagulation disorders. Rational use of antibiotics, anticoagulants, and antitumor drugs must be guaranteed.

Bone Tissue Engineering (BTE) of the Craniofacial Skeleton, Part I: Evolution and Optimization of 3D-Printed Scaffolds for Repair of Defects

Bone tissue regeneration is a complex process that proceeds along the well-established wound healing pathway of hemostasis, inflammation, proliferation, and remodeling. Recently, tissue engineering efforts have focused on the application of biological and technological principles for the development of soft and hard tissue substitutes. Aim is directed towards boosting pathways of the healing process to restore form and function of tissue deficits. Continued development of synthetic scaffolds, cell therapies, and signaling biomolecules seeks to minimize the need for autografting. Despite being the current gold standard treatment, it is limited by donor sites' size and shape, as well as donor site morbidity. Since the advent of computer-aided design/computer-aided manufacturing (CAD/CAM) and additive manufacturing (AM) techniques (3D printing), bioengineering has expanded markedly while continuing to present innovative approaches to oral and craniofacial skeletal reconstruction. Prime examples include customizable, high-strength, load bearing, bioactive ceramic scaffolds. Porous macro- and micro-architecture along with the surface topography of 3D printed scaffolds favors osteoconduction and vascular in-growth, as well as the incorporation of stem and/or other osteoprogenitor cells and growth factors. This includes platelet concentrates (PCs), bone morphogenetic proteins (BMPs), and some pharmacological agents, such as dipyridamole (DIPY), an adenosine A 2A receptor indirect agonist that enhances osteogenic and osteoinductive capacity, thus improving bone formation. This two-part review commences by presenting current biological and engineering principles of bone regeneration utilized to produce 3D-printed ceramic scaffolds with the goal to create a viable alternative to autografts for craniofacial skeleton reconstruction. Part II comprehensively examines recent preclinical data to elucidate the potential clinical translation of such 3D-printed ceramic scaffolds.

Practice patterns in the management of pediatric iliofemoral arterial thrombosis

BACKGROUND

Acute arterial thrombosis can be life- and limb-threatening. Most pediatric patients with iliofemoral arterial thrombosis are treated successfully with medical therapy; however, expert consensus is limited, and many recommendations are based on the extrapolation of adult data. We aim to understand treatment patterns and long-term outcomes after pediatric acute iliofemoral arterial thrombosis, from which management recommendations can be informed.

METHODS

A single-institution retrospective study of pediatric patients diagnosed with iliofemoral arterial thrombosis from 2009 to 2018 was performed. Multiple parameters of management and follow-up were evaluated. Children anticoagulated for ≤28 days versus >28 days were compared. Data analysis used Fisher exact and Mann-Whitney U tests.

RESULTS

Two hundred thirty-six children were included. Median age at diagnosis was 65 days (interquartile range 17-163), with 207 diagnosed as infants, 15 diagnosed between 1 to 2 years, and 14 diagnosed between 2 to 16 years. The median treatment duration was 28 days (interquartile range 13-42); patients treated for >28 days had a longer time for thrombus resolution, and more follow-up ultrasounds were performed. Limb length discrepancy did not differ between the groups (1.0% vs 6.3%, P = .06), and no patients were documented to have developed peripheral arterial disease over a median 6.5-year follow-up. Multiple treatment strategies were employed, the most common being heparin bridged to enoxaparin (25.0%) and enoxaparin monotherapy (21.6%). Eight patients (3.4%) underwent surgical intervention.

CONCLUSION

Pediatric iliofemoral arterial thrombosis is primarily a disease of infants treated adequately with heparin or enoxaparin, infrequently requires surgical intervention, and is rarely associated with long-term complications. When guided by thrombus resolution on ultrasound, a four-week or shorter course of anticoagulation does not increase the need for surgical intervention or long-term complications.

Efficacy and safety of direct oral anticoagulants in the pediatric population: a systematic review and a meta-analysis

BACKGROUND

Direct oral anticoagulants (DOACs) represent a cornerstone of adult venous thromboembolism (VTE) treatment. Recently, randomized controlled trials (RCTs) investigating DOACs in pediatrics have been performed.

OBJECTIVES

To evaluate the efficacy and safety of DOACs in the pediatric population.

METHODS

We systematically searched MEDLINE (PubMed), EMBASE, and ClinicalTrials.gov from initiation up to August 20, 2022, for RCTs comparing DOACs to standard of care (SOC) in patients aged <18 years according to PRISMA guidelines (PROSPERO registration CRD42022353870). The primary analysis was performed according to the anticoagulation intensity and clinical setting (ie, prophylaxis in cardiac disease or treatment in VTE). Efficacy outcomes were all-cause mortality and VTE. Safety outcomes were major bleeding (MB), clinically relevant non-MB, any bleeding, serious adverse events, and discontinuation due to adverse events (AEs).

RESULTS

Seven RCTs were included in the systematic review and 6 in the meta-analysis (3 prophylaxis in cardiac disease and 3 treatment in VTE). DOACs showed a significant reduction of VTE recurrence for treatment (odds ratio [OR] = 0.42; 95% CI, 0.19-0.94) and a nonsignificant reduction in VTE occurrence in prophylaxis (OR = 0.22; 95% CI, 0.03-1.55). No differences were observed for any bleeding, serious AEs, and MB in prophylaxis. Nonsignificant trends were observed for clinically relevant non-MB, MB in treatment, and discontinuation due to AE in prophylaxis. We found a significant increase in discontinuation due to AE in treatment.

CONCLUSIONS

DOAC treatment seems to reduce VTE compared with SOC without major safety issues in the pediatric population, whereas DOAC prophylaxis seems at least comparable to SOC.

Questions around a case of in utero thrombosis in a premature child, concerning the management of anticoagulant treatments

We report the case of a preterm infant presenting a thrombosis, discovered on ultrasound at 22 weeks of gestational age and confirmed at birth following additional examinations. We describe the anticoagulant treatment of this patient by intravenous enoxaparin, tinzaparin and rivaroxaban, from questioning to practice.

The Hemostatic System in Newborns and the Risk of Neonatal Thrombosis

Newborns are the most vulnerable patients for thrombosis development among all children, with critically ill and premature infants being in the highest risk group. The upward trend in the rate of neonatal thrombosis could be attributed to progress in the treatment of severe neonatal conditions and the increased survival in premature babies. There are physiological differences in the hemostatic system between neonates and adults. Neonates differ in concentrations and rate of synthesis of most coagulation factors, turnover rates, the ability to regulate thrombin and plasmin, and in greater variability compared to adults. Natural inhibitors of coagulation (protein C, protein S, antithrombin, heparin cofactor II) and vitamin K-dependent coagulation factors (factors II, VII, IX, X) are low, but factor VIII and von Willebrand factor are elevated. Newborns have decreased fibrinolytic activity. In the healthy neonate, the balance is maintained but appears more easily converted into thrombosis. Neonatal hemostasis has less buffer capacity, and almost 95% of thrombosis is provoked. Different triggering risk factors are responsible for thrombosis in neonates, but the most important risk factors for thrombosis are central catheters, fluid fluctuations, liver dysfunction, and septic and inflammatory conditions. Low-molecular-weight heparins are the agents of choice for anticoagulation.

Mechanical atrioventricular valve replacement in patients with single ventricle palliation

OBJECTIVES

Atrioventricular valve (AVV) replacements in patients with single-ventricle circulations pose significant surgical risks and are associated with high morbidity and mortality.

METHODS

From 1997 to 2021, 16 consecutive patients with functionally single-ventricle physiology underwent mechanical AVV replacement. Primary outcome was transplant-free survival. Secondary outcomes included major postoperative morbidity.

RESULTS

The median age of AVV replacement was 2 years old (interquartile range 0.6-3.8 years). All AVV replacements were performed with a St. Jude Medical mechanical valve, median 24 mm (range, 19-31mm). Extracorporeal membrane oxygenation (ECMO) was required in 4 patients. Operative mortality was 38% (6/16). There were 2 late deaths and 3 transplants. Transplant-free survival was 50% at 1 year, 37.5% at 5 years, and 22% at 10 years. Transplant-free survival was higher for patients with preserved ventricular function (P = 0.01). Difference in transplant-free survival at 1 year was 75% vs 25%, at 5 years was 62.5% vs 12.5% and at 10 years was 57% vs 0%. Three (19%) patients had complete heart block requiring permanent pacemaker insertion. 6 of 13 patients (46%) patients reached Fontan completion (3 patients operated at/after Fontan). Significant bleeding events occurred in 8 patients (50%) with 3 patients suffering major cerebrovascular accidents. There were 6 events of valve thrombosis in 5 patients, resulting in 2 deaths and 2 heart transplants.

CONCLUSIONS

Mechanical valve replacement carries significant morbidity and mortality risk. While it successfully salvages about half of patients with preserved ventricular function, careful consideration of alternative options should be made before embarking upon mechanical valve replacement.

Renal vein thrombosis in neonates: a case series of diagnosis, treatment and childhood kidney function follow-up

BACKGROUND

Neonatal renal vein thrombosis (NRVT) is a rare condition with little data available.

METHODS

We retrospectively analyzed newborns diagnosed with NRVT admitted to 3 pediatric nephrology units in Paris from 2005 to 2020.

RESULTS

Twenty-seven patients were analyzed (male = 59%). The median age at diagnosis was 2.5 days (1 - 4.5). Diagnosis was suspected based on at least one of the three cardinal signs of renal vein thrombosis in 93%: flank mass (67%), hematuria (67%) and thrombocytopenia (70%). In all patients, diagnosis was confirmed by ultrasound. All patients had at least one known perinatal risk factor. A prothrombotic risk factor was found in 13 patients (48%). NRVT was unilateral in 70%, involving the left renal vein in 58%. Among 25 treated patients, 19 (76%) received low molecular weight heparin (LMWH) as initial therapy, 2 (8%) received unfractionated heparin and 4 (16%) received fibrinolysis. Median duration of treatment was 8 weeks (4 - 12). Bleeding occurred significantly more often with fibrinolysis than with LMWH/supportive therapy (3 of 4: 75% vs 0 of 4: 0%, p = 0.05). Clot resolution in patients treated with fibrinolysis did not differ significantly from those treated with LMWH/supportive therapy. After a median follow-up of 5.7 years (3 years - 9.9 years), pathological kidney features were observed in 73% of the patients (19 of 26), kidney atrophy in 18 (69%), hypertension in 2 (8%), chronic kidney disease (CKD) in 1 (4%) and proteinuria in 2 (8%).

CONCLUSIONS

NRVT remains a challenging condition, which still requires further study because of its associated morbidity. A higher resolution version of the Graphical abstract is available as Supplementary information.

French National Diagnostic and Care Protocol for antiphospholipid syndrome in adults and children

Antiphospholipid syndrome (APS) is a chronic autoimmune disease involving vascular thrombosis and/or obstetric morbidity and persistent antibodies to phospholipids or certain phospholipid-associated proteins. It is a rare condition in adults and even rarer in children. The diagnosis of APS can be facilitated by the use of classification criteria based on a combination of clinical and biological features. APS may be rapidly progressive with multiple, often synchronous thromboses, resulting in life-threatening multiple organ failure. This form is known as "catastrophic antiphospholipid syndrome" (CAPS). It may be primary or associated with systemic lupus erythematosus (associated APS) and in very rare cases with other systemic autoimmune diseases. General practitioners and paediatricians may encounter APS in patients with one or more vascular thromboses. Because APS is so rare and difficult to diagnosis (risk of overdiagnosis) any suspected case should be confirmed rapidly and sometimes urgently by an APS specialist. First-line treatment of thrombotic events in APS includes heparin followed by long-term anticoagulation with a VKA, usually warfarin. Except in the specific case of stroke, anticoagulants should be started as early as possible. Any temporary discontinuation of anticoagulants is associated with a high risk of thrombosis in APS. A reference/competence centre specialised in autoimmune diseases must be urgently consulted for the therapeutic management of CAPS.

Pediatric Spinal Cord Injury: A Review

A spinal cord injury (SCI) can be a devastating condition in children, with profound implications for their overall health and quality of life. In this review, we aim to provide a concise overview of the key aspects associated with SCIs in the pediatric population. Firstly, we discuss the etiology and epidemiology of SCIs in children, highlighting the diverse range of causes. We explore the unique anatomical and physiological characteristics of the developing spinal cord that contribute to the specific challenges faced by pediatric patients. Next, we delve into the clinical presentation and diagnostic methods, emphasizing the importance of prompt and accurate diagnosis to facilitate appropriate interventions. Furthermore, we approach the multidisciplinary management of pediatric SCIs, encompassing acute medical care, surgical interventions, and ongoing supportive therapies. Finally, we explore emerging research as well as innovative therapies in the field, and we emphasize the need for continued advancements in understanding and treating SCIs in children to improve their functional independence and overall quality of life.

Native Aortic Root Thrombosis in Hypoplastic Left Heart Syndrome: An Unusual Presentation (Soon after Atrial Septal Stenting) of a Relatively Unusual Complication-Experience and Literature Review with an Outlook to Diagnosis and Management

We started with the experience of thrombus formation in the native aorta of a 3-year-old male child with hypoplastic left heart syndrome (HLHS) and severely hypoplastic but patent mitral and aortic valves after Glenn palliation, which occurred soon after left heart decompression by percutaneous stenting of the atrial septum. The diagnosis was incidental, with the child completely asymptomatic, and progressively subsided in a few days with heparin infusion and chronic warfarin therapy. We reviewed the incidence, diagnosis, and management of native aortic thrombosis in HLHS after different stages of Fontan palliation through a systematic literature search. In all 32 cases, native aortic thrombosis in HLHS was found. The HLHS anatomic subtypes included mitral stenosis/aortic stenosis (fourteen cases or 45.2%), mitral stenosis/aortic atresia (eleven cases or 35.5%), and mitral atresia/aortic atresia (four cases or 12.9%). The age at diagnosis ranged from 13 days to 18 years. Clinical presentation varied from incidental findings, chest pain and/or electrocardiographic abnormalities, cardiac arrest, and transient ischemic attack. Diagnosis was feasible in most of the cases with only transthoracic echocardiography. Mostly (59.4%), patients were treated with anticoagulation, while others underwent surgical (18.7%), direct (12.5%), or systemic (9.3%) thrombolysis. Transplant-free survival was 56.2%, and fatal events occurred in 25%. Major events occurred in 26.3% of those treated with anticoagulation, in 33.3% of patients treated with surgical/systemic thrombolysis, and in 100% of patients treated with direct thrombolysis. In summary, native aortic thrombosis in HLHS may occur at different ages, with a wide spectrum of presentation from incidental finding to a sudden major event. Diagnosis is feasible with transthoracic echocardiography, and management with anticoagulation is effective despite the incidence of major events remaining high.

Lung abscess as a complication of Lemierre Syndrome in adolescents: a single center case reports and review of the literature

BACKGROUND

Fusobacterium necrophorum is an anaerobic, gram-negative, non-motile, filamentous, non-spore forming bacillus found in the oral cavity, gastrointestinal tract, and female genital tract, responsible of a rare disease named Lemierre Syndrome, characterized by septic thrombophlebitis of the internal jugular vein, which mainly affects previously healthy adolescents and young adults; some risk factors are reported, as smoking or primary viral or bacterial infection leading to the disruption of mucosa. The syndrome originates commonly from an upper respiratory infection such as pharyngotonsillitis, acute otitis media, cervical lymphadenitis, sinusitis, or odontogenic abscess, and may result in multiorgan metastasis, more frequently leading to pulmonary complications, especially lung abscesses.

CASE PRESENTATION

We describe two cases of adolescents with atypical Lemierre Syndrome evaluated in a tertiary care center, one with a confirmed infection by Fusobacterium necrophorum and one with a presumptive diagnosis based on clinical features, who developed lung abscesses needing a prolonged antibiotic course and hospitalization. Of interest, both were user of electronic cigarette, configuring a possible new risk factor. The proper diagnosis of Lemierre Syndrome is often difficult to establish, so a high degree of suspicion is needed, especially in the case of lung abscesses in otherwise healthy adolescents.

CONCLUSION

The current study will contribute to providing insight into Lemierre Syndrome clinical presentation and management in adolescents, promoting awareness for a rare but potentially fatal disease. Moreover, it suggests a possible relationship between Lemierre syndrome and the use of electronic cigarette, that should be investigated by future studies.

Stroke in Pediatric Cancer Patients: A Systematic Review

OBJECTIVE

Pediatric cancer patients have an increased risk of stroke. However, there is a knowledge gap regarding stroke in early stages of pediatric cancer. The objective of this project is to describe the current knowledge on stroke in pediatric cancer patients.

DESIGN

Systematic review.

MATERIALS AND METHODS

After Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, literature search was conducted in PubMed, Cochrane, and Google Scholar from January 1, 1995, up to February 1, 2022.

RESULTS

A total of 3499 studies were identified, of which 8 met inclusion criteria. The incidence of stroke in pediatric cancer patients varied between 0.47% and 2.9%, and prevalence between 1% and 3%. The risk factors identified were leukemia diagnosis, cranial radiation, thrombocytopenia, coagulopathy, and infection. There was a higher rate of diagnosis with magnetic resonance imaging than with computed tomography scan. Treatment was inconsistent, and patients with cancer were less likely to receive antithrombotic treatment when compared with patients without cancer. The highest mortality was among hemorrhagic stroke. Recurrence rate was 5% to 19%.

CONCLUSIONS

The risk for stroke is increased in the pediatric cancer population and can lead to devastating results. The available reports include few patients, with heterogeneous cancer diagnoses and outcomes. Large-scale multicenter studies are needed, focusing on early diagnosis, risk factors, and management strategies of stroke in children with underlying cancer.

Consistent Correlation between MTHFR and Vascular Thrombosis in Neonates-Case Series and Clinical Considerations

BACKGROUND

MTHFR polymorphism has been inconsistently linked to thrombotic events-some studies have shown its contribution to venous thrombosis, arterial thrombosis, and ischemic stroke, whereas others have found no statistically significant correlation between them.

METHODS

A descriptive case series study was performed in the Neonatal Intensive Care Unit of "Marie Sklodowska Curie" Emergency Clinical Hospital for Children in Bucharest, Romania.

RESULTS

All patients had positive results for MTHFR variants; 14 patients were positive for compound heterozygosity, 13 patients for MTHFR C677T (seven of which were homozygous), and 13 patients for MTHFR A1298C (three of which were homozygous). Eighteen patients received anticoagulants (heparin, enoxaparin, or bivalirudin), and thrombolytics (alteplase) were administered in six cases. In one case, a thrombectomy was performed; in another, vascular plasty was undertaken. Only in six cases was complete revascularization possible. Incomplete revascularization occurred for one patient with a negative outcome.

CONCLUSION

The particularity of this case series is that every patient in our unit who developed thrombi had a positive genetic result for MTHFR mutations. MTHFR mutations should be regarded as a thrombotic risk factor for critically ill patients, and screening for MTHFR mutations should be performed in every admitted patient to intensive care units, thus achieving the prevention of thrombi.

Once-daily Compared With Twice-daily Enoxaparin Maintenance Therapy Appears Safe and Efficacious in Pediatric Venous Thromboembolism

INTRODUCTION

Once-daily enoxaparin (ODE), considered standard of care for venous thromboembolism (VTE) treatment in adults, has been infrequently assessed in children. To contribute available data to a limited field, we reviewed our center's experience with ODE in treating pediatric VTE compared with twice-daily enoxaparin (TDE).

MATERIALS AND METHODS

A retrospective analysis of children and adolescents 18 years of age or below diagnosed with VTE and treated at our institution with ODE or TDE maintenance therapy between April 2015 and December 2020 was performed. Patient demographics, clinical and laboratory data pertaining to VTE diagnosis, and management were gathered from electronic medical records and compared between the 2 cohorts.

RESULTS

Seventy-one children met the eligibility criteria. All patients were initially treated with TDE for 2 weeks before transitioning to ODE maintenance therapy (n=39; 55%) or continuing with TDE dosing (n=32; 45%).Extremity VTE was more common in ODE ( P =0.051) versus pulmonary/intracardiac sites in TDE ( P =0.002) when compared with other sites. Median enoxaparin dosing was 1.5 and 1.1 mg/kg/dose in ODE and TDE cohorts, respectively. Bleeding episodes were rare without any difference between the cohorts. Two patients (6%) were lost to follow up in TDE cohort. All evaluable patients in both cohorts had either complete/partial response (ODE n=35 [90%]; TDE n=24 [75%] or stable thrombus ODE n=4 [10%]; TDE n=6 [19%]).

CONCLUSIONS

Our results indicate that ODE, used after the initial TDE treatment period, is as safe and efficacious as TDE maintenance for the treatment of pediatric VTE. The difference in VTE sites may have contributed to the equal efficacy of both the cohorts. Future prospective studies in pediatric VTE are needed to validate these results.