The COVID-19 pandemic is an ongoing global healthcare crisis. Based on reports of atypically located thromboses following vaccination with the AstraZeneca COVID-19 vaccine, the Society of Thrombosis and Haemostasis Research (GTH) has issued guidance statements on the recognition, diagnosis, and treatment of this rare complication. It shares pathophysiological features with heparin-induced thrombocytopenia (HIT) and is referred to as vaccine-induced prothrombotic immune thrombocytopenia (VIPIT).

Background-The aim of this study was to estimate the impact of thrombophilia on risk of first childhood stroke through a meta-analysis of published observational studies. Methods and Results-A systematic search of electronic databases (Medline via PubMed, EMBASE, OVID, Web ofScience, The Cochrane Library) for studies published from 1970 to 2009 was conducted. Data on year of publication, study design, country of origin, number of patients/control subjects, ethnicity, stroke type (arterial ischemic stroke [AIS], cerebral venous sinus thrombosis [CSVT]) were abstracted. Publication bias indicator and heterogeneity across studies were evaluated, and summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with fixed-effects or random-effects models. Twenty-two of 185 references met inclusion criteria. Thus, 1764 patients (arterial ischemic stroke [AIS], 1526; cerebral sinus venous thrombosis [CSVT], 238) and 2799 control subjects (neonate to 18 years of age) were enrolled. No significant heterogeneity was discerned across studies, and no publication bias was detected. A statistically significant association with first stroke was demonstrated for each thrombophilia trait evaluated, with no difference found between AIS and CSVT. Summary ORs (fixed-effects model) were as follows: antithrombin deficiency, 7.06 (95% CI, 2.44 to 22.42); protein C deficiency, 8.76 (95% CI, 4.53 to 16.96); protein S deficiency, 3.20 (95% CI, 1.22 to 8.40), factor V G1691A, 3.26 (95% CI, 2.59 to 4.10); factor II G20210A, 2.43 (95% CI, 1.67 to 3.51); MTHFR C677T (AIS), 1.58 (95% CI, 1.20 to 2.08); antiphospholipid antibodies (AIS) [CSVT]) is estimated to be between 2.6 and 6.4 per 100 000 per year, reflecting a trend toward a higher frequency in more current literature. 1-3 Underlying conditions in children with symptomatic cerebrovascular accidents include congenital heart malformations, hemolytic anemias, and collagen vascular diseases, as well as some rare inborn metabolic disorders. 4 In addition, risk factors include trauma and infectious diseases. Apart from acquired thrombophilic risk factors such as the presence of antiphospholipid antibodies, 5,6 inherited thrombophilia, particularly antithrombin, protein C, and protein S deficiency, variants of coagulation factor V (G1691A) and factor II (G20210A), and elevated lipoprotein(a), have been found in small case series and case-control studies to be associated with AIS or CSVT in infants and children. Furthermore, an association of the thermolabile MTHFR C677T genotype with stroke is controversial in both adults and children. 5353 In fact, the increased likelihood of having a blood clot in the vasculature is related to elevated homocysteine levels, and mutations in the MTHFR gene only exploit their effect by contributing to the elevated homocysteine plasma level. Because adequate folate levels essentially cancel out the impaired regulation of homocysteine induced by MTHFR mutations, not all people will develop high homocysteine levels. [53][54][55][56] , Editori...

Background: Observational studies indicate that children hospitalized with COVID-19-related illness, like adults, are at increased risk for venous thromboembolism (VTE). A multicenter phase 2 clinical trial of anticoagulant thromboprophylaxis in

Background: Contrast-enhanced CMR angiography (CE-CMRA) is being increasingly used for diagnosing aortic arch anomalies, planning interventions and follow-up assessment. We sought to establish normal values for the diameters of the thoracic aorta and reference curves related to body growth in children using CE-CMRA.

This open-label, single-arm, prospective cohort trial is the first phase 3 safety study to describe outcomes in children treated with dabigatran etexilate for secondary venous thromboembolism (VTE) prevention. Eligible children aged 12 to <18 years (age stratum 1), 2 to <12 years (stratum 2), and >3 months to <2 years (stratum 3) had an objectively confirmed diagnosis of VTE treated with standard of care (SOC) for ≥3 months, or had completed dabigatran or SOC treatment in the DIVERSITY trial (NCT01895777) and had an unresolved clinical thrombosis risk factor requiring further anticoagulation. Children received dabigatran for up to 12 months, or less if the identified VTE clinical risk factor resolved. Primary end points included VTE recurrence, bleeding events, and mortality at 6 and 12 months. Overall, 203 children received dabigatran, with median exposure being 36.3 weeks (range, 0-57 weeks); 171 of 203 (84.2%) and 32 of 203 (15.8%) took capsules and pellets, respectively. Overall, 2 of 203 children (1.0%) experienced on-treatment VTE recurrence, and 3 of 203 (1.5%) experienced major bleeding events, with 2 (1.0%) reporting clinically relevant nonmajor bleeding events, and 37 (18.2%) minor bleeding events. There were no on-treatment deaths. On-treatment postthrombotic syndrome was reported for 2 of 162 children (1.2%) who had deep vein thrombosis or central-line thrombosis as their most recent VTE. Pharmacokinetic/pharmacodynamic relationships of dabigatran were similar to those in adult VTE patients. In summary, dabigatran showed a favorable safety profile for secondary VTE prevention in children aged from >3 months to <18 years with persistent VTE risk factor(s). This trial was registered at www.clinicaltrials.gov as #NCT02197416.