Risk factors for haemodynamic compromise in multisystem inflammatory syndrome in children: A multicentre retrospective study

Objectives: To identify predictors of a severe clinical course of multisystem inflammatory syndrome in children (MIS-C), as defined by the need for inotropic support. Methods: This retrospective study included patients diagnosed with MIS-C (according to the CDC definition) in nine Israeli and one US medical centre between July 2020 and March 2021. Univariate and multivariate regression models assessed odds ratio (OR) of demographic, clinical, laboratory and imaging variables during admission and hospitalization for severe disease. Results: Of 100 patients, 61 (61%) were male; mean age 9.65 (4.48) years. Sixty-five patients were hypotensive, 44 required inotropic support. Eleven patients with MIS-C fulfilled Kawasaki disease diagnostic criteria; 87 had gastrointestinal symptoms on admission. Echocardiographic evaluation showed 10 patients with acute coronary ectasia or aneurysm, and 37 with left ventricular dysfunction. In a univariate model, left ventricular dysfunction was associated with severe disease [OR 4.178 (95% CI 1.760, 9.917)], while conjunctivitis [OR 0.403 (95% CI 0.173, 0.938)] and mucosal changes [OR 0.333 (95% CI 0.119, 0.931)] at admission were protective. Laboratory markers for a severe disease course were low values of haemoglobin, platelets, albumin and potassium; and high leukocytes, neutrophils, troponin and brain natriuretic peptide. In multivariate analysis, central nervous system involvement and fever >39.5°C were associated with severe disease. Mucosal involvement showed 6.2-fold lower risk for severe disease. Low haemoglobin and platelet count, and elevated C-reactive protein and troponin levels were identified as risk factors for severe disease. Conclusion: Key clinical and laboratory parameters of MIS-C were identified as risk factors for severe disease, predominantly during the disease course and not at the time of admission; and may prompt close monitoring, and earlier, more aggressive treatment decisions. Patients presenting with a Kawasaki-like phenotype were less likely to require inotropic support.