Longitudinal Assessment of Cardiac Outcomes of Multisystem Inflammatory Syndrome in Children Associated With COVID‐19 Infections

Abstract

Background In multisystem inflammatory syndrome in children, there is paucity of longitudinal data on cardiac outcomes. We analyzed cardiac outcomes 3 to 4 months after initial presentation using echocardiography and cardiac magnetic resonance imaging. Methods and Results We included 60 controls and 60 cases of multisystem inflammatory syndrome in children. Conventional echocardiograms and deformation parameters were analyzed at 4 time points: (1) acute phase (n=60), (2) subacute phase (n=50; median, 3 days after initial echocardiography), (3) 1‐month follow‐up (n=39; median, 22 days), and (4) 3‐ to 4‐month follow‐up (n=25; median, 91 days). Fourteen consecutive cardiac magnetic resonance imaging studies were reviewed for myocardial edema or fibrosis during subacute (n=5) and follow‐up (n=9) stages. In acute phase, myocardial injury was defined as troponin‐I level ≥0.09 ng/mL (>3 times normal) or brain‐type natriuretic peptide >800 pg/mL. All deformation parameters, including left ventricular global longitudinal strain, peak left atrial strain, longitudinal early diastolic strain rate, and right ventricular free wall strain, recovered quickly within the first week, followed by continued improvement and complete normalization by 3 months. Median time to normalization of both global longitudinal strain and left atrial strain was 6 days (95% CI, 3–9 days). Myocardial injury at presentation (70% of multisystem inflammatory syndrome in children cases) did not affect short‐term outcomes. Four patients (7%) had small coronary aneurysms at presentation, all of which resolved. Only 1 of 9 patients had residual edema but no fibrosis by cardiac magnetic resonance imaging. Conclusions Our short‐term study suggests that functional recovery and coronary outcomes are good in multisystem inflammatory syndrome in children. Use of sensitive deformation parameters provides further reassurance that there is no persistent subclinical dysfunction after 3 months.

COVID-19-Vaccination-Induced Myocarditis in Teenagers: Case Series with Further Follow-Up

“…Moreover, elevated troponin concentration, before the outbreak of the COVID-19 pandemic, was recognised as a poor prognostic marker in adult patients with acute coronary syndrome, as well as in children with acute fulminant myocarditis [ 26 ]. Contrarily, according to a retrospective by Matsubara et al, longitudinal cohort study troponin concentration seems to not be correlated with worse clinical implications in children with paediatric inflammatory multisystem syndrome temporary, associated with SARS-CoV-2 (PIMS-TS) [ 27 ]. In view of the above, and the supposed immune mechanism of PIMS-TS and COVID-19-vaccine-related myocarditis, the troponin level appears to not reflect the CMR findings in wither of the abovementioned groups.…”

Validity of reported post-acute health outcomes in children with SARS-CoV-2 infection: a systematic review

“…Orange-colored: estimates and 95%-CI for children with SARS-CoV-2 infection; blue-colored: estimates and confidence intervals for children without SARS-CoV-2 infection in the 6 controlled studies 29-34 .…”

“…Risk of misclassification bias due to ambiguous definition of infection status was low for 14 uncontrolled studies that identified patients based on RT-PCR tests during acute COVID-19 30,32,35-44,47-49 .Three controlled studies 29,31,32 had moderate risk of bias either because positive infection status was defined by serology, but the infection time point was unclear or because negative infection status was defined by RT-PCR, but previous infection could not be excluded. The other 3 controlled studies 30,33,34 had serious risk of bias because negative infection status was determined on the basis of having no documented COVID-19 diagnosis 30 or symptoms 33,34 regardless of laboratory virus detection. Risk of bias due to missing data was serious in 14 studies, because loss-to-follow-up was either>20% 29,31-34,37,39,40,42,43,48,49 or the information provided was unclear 35,38 .…”

“…Twenty-one studies were eligible (Table 1; Supplementary material: eFigure1). Six studies had a control group [29][30][31][32][33][34] and 15 were uncontrolled [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] . Twelve studies were conducted in Europe [29][30][31][32][33]36,[38][39][40]44,47,49 and 18 published in 2021 [29][30][31][32][33][35][36][37][39][40][41][42][43][44][45][46][47]…”

“…Twelve studies were conducted in Europe [29][30][31][32][33]36,[38][39][40]44,47,49 and 18 published in 2021 [29][30][31][32][33][35][36][37][39][40][41][42][43][44][45][46][47][48] . Thirteen studies used data that were specifically collected for the purpose of the study 29,[31][32][33][35][36][37][38][39][40]42,45,47,48 , 5 studies used routinely collected data 30,34,41,44,49 and the type of data was unclear in 2 studies 43,…”