Coagulation Profiles and Viscoelastic Testing in Multisystem Inflammatory Syndrome

Objective: To characterize viscoelastic testing profiles of children with multisystem inflammatory syndrome in children (MIS-C). Methods: This single-center retrospective review included 30 patients diagnosed with MIS-C from January 1 to September 1, 2020. Thromboelastography (TEG) with platelet mapping was performed in 19 (63%) patients and compared to age- and gender- matched controls via Student’s t-test and Wilcoxon rank sum test. Pearson’s and Spearman correlation were used to assess relationships between TEG parameters and inflammatory markers. Results: Patients with MIS-C had abnormal TEG results compared to controls, including decreased K time (1.1 vs. 1.7 min, P<0.01), increased alpha angle (75.0 vs. 65.7 degrees, P<0.01), increased maximum amplitude (70.8 vs. 58.3 mm, P<0.01), and decreased Ly-30 (1.1 vs. 3.7%, P=0.03); consistent with increased clot formation rate and strength, and slower fibrinolysis. TEG maximum amplitude was moderately correlated with erythrocyte sedimentation rate (r=0.60, P=0.02), initial platelet count (r=0.67, P<0.01), and peak platelet count (r=0.51, P=0.03). TEG alpha angle was moderately correlated with peak platelet count (r=0.54, P=0.02). 17 (57%) patients received aspirin (ASA) and anticoagulation, 5 (17%) received only ASA, and 3 (10%) received only anticoagulation. No patients had a thrombotic event. 6 (20%) patients had a bleeding event, none of which was major. Conclusions: Patients with MIS-C had evidence of hypercoagulability on TEG. Increased erythrocyte sedimentation rate and platelets were associated with higher clot strength. Treatment with ASA or anticoagulation was well tolerated. Further multi-center study is required to characterize the rate of thrombosis and optimal thromboprophylaxis algorithm in this patient population.