Echocardiographic assessment of strain and associations with markers of clinical severity in multisystem inflammatory syndrome in children (MIS-c) associated with covid-19

ABSTRACT

Introduction: Multisystem Inflammatory Syndrome in Children (MIS-C) associated with COVID-19 can cause cardiovascular dysfunction. We aimed to determine if strain abnormalities persist in MISC patients 3-10 weeks post-discharge, and whether acute markers of clinical severity are associated with lower strain at subacute follow-up. Methods: We performed a retrospective cohort study of MIS-C patients admitted at a single center from 3/2020-3/2021. Demographic and clinical variables during hospitalization were obtained. Global longitudinal strain (GLS), 4-chamber longitudinal strain (4C-LS), mid-papillary circumferential strain (CS), and left atrial strain (LAS) at 3-10 week follow-up were compared to age matched controls (n=10). Bivariate analyses were performed using Spearman rank correlation and twosample t-test or Wilcoxon rank sum test. Results: Sixty MIS-C patients were identified (age 8.9 +/-4 years, 35/60 male, 39% Hispanic, 29% African American). Hypotension (65%), ICU admission (57%), and inotropic support (45%) were common;7% received mechanical ventilation. No deaths or need for ECMO were reported. Median length of stay (LOS) was 7 days. LVEF was <55% in 28% during hospitalization (median 57% [52-61]) and 6% at follow-up (median 65% [61-67]). Peak NT-proBNP (median 5321 pg/ml [IQR 1712, 17400]) and peak CRP (median 17 mg/dl [12, 22]) were significantly associated with hypotension, ICU admission, and total ICU days. Forty-five patients had available follow-up imaging for strain. CS (mean-26.0 vs-28.6;p=0.009) and LAS (mean-34.5 vs-51.2;p=0.001) were lower in MIS-C vs controls, but not GLS or 4C-LS. Lower CS (-24.2 +/-3.1 vs-26.7 +/-2.7;p=0.04) and lower 4C-LS (-19.1 +/-1.9 vs-21.2 +/-3.3;p=0.04) were associated with abnormal EF (<55%) during acute illness. CS was lower in those admitted to ICU (-25.1 +/-2.6 vs-27.5 +/-2.9;p=0.03). Peak CRP correlated with lower CS (r=-0.41, p=0.03) and GLS (r=-0.55, p=0.01) at follow-up. Conclusions: MIS-C patients show abnormal strain during subacute follow-up despite improvement in EF. Lower CS, GLS, and 4C-LS were associated with in-hospital markers of clinical severity. This data may allow for identification of at-risk MIS-C patients and help guide outpatient cardiology follow-up.