Introduction
Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus
SARS-CoV-2, has had a tremendous impact since the first cases were
reported in China in December 2019. Since April 2020, cases have emerged
of healthy children presenting with a severe, immune-mediated,
multi-organ system illness following SARS-CoV-2 infection, which has
since been termed “multisystem inflammatory syndrome in children”
(MIS-C).1–5 Patients with MIS-C have evidence of
significant abnormalities in the inflammatory cascade and hemostasis,
including elevated fibrinogen and D-dimer.6–9Reported rates of thromboembolism in the pediatric MIS-C population
range from 3 to 6.5%.6,10,11 Derangements in
hemostasis in adults with severe COVID-19 infection are more pronounced
and better characterized. In the adult literature, SARS-CoV-2 infection
is associated with a prothrombotic state, with viscoelastic testing
consistent with early thrombin burst, increased fibrin generation,
greater clot strength and reduced fibrinolysis.12–14This has been consistent with evidence that approximately 20-40% of
adults with severe acute COVID-19 infection in intensive care units
(ICU’s) are affected by thromboembolism despite
anticoagulation.15–17
Thromboelastography (TEG) is a point of care, whole blood viscoelastic
test that is widely established in adults and used to characterize clot
formation and lysis kinetics as well as clot
strength.18 Increased in vitro clot strength on
TEG is associated with increased risk of thromboembolism in critically
ill adult patients.19 TEG has shown promise in
pediatric care, including guiding management of product resuscitation
and thrombosis risk.20–22 We sought to describe the
coagulation and viscoelastic testing profiles of children with MIS-C at
our institution, as well as our approach to thromboprophylaxis in these
patients.