Strain Echocardiography and Myocardial Dysfunction in Critically Ill Children With Multisystem Inflammatory Syndrome Unrecognized by Conventional Echocardiography: A Retrospective Cohort Analysis

OBJECTIVES: Multisystem inflammatory syndrome in children is a newly defined complication of severe acute respiratory syndrome coronavirus 2 infection that can result in cardiogenic shock in the pediatric population. Early detection of cardiac dysfunction is imperative in directing therapy and identifying patients at highest risk for deterioration. This study compares the strengths of conventional and strain echocardiography in identifying cardiac dysfunction in critically ill children with multisystem inflammatory syndrome in children and their association with ICU therapeutic needs and clinical outcomes. DESIGN: Retrospective, observational cohort study. SETTING: A large, quaternary care PICU. PATIENTS: Sixty-five pediatric patients admitted to the PICU with the diagnosis of multisystem inflammatory syndrome in children from March 2020 to March 2021. INTERVENTIONS: Global longitudinal strain four chamber was measured retrospectively by strain echocardiography and compared with conventional echocardiography. Cardiac dysfunction was defined by left ventricular ejection fraction less than 55% and global longitudinal strain four chamber greater than or equal to -17.2%. Clinical variables examined included cardiac biomarkers, immune therapies, and ICU interventions and outcomes. MEASUREMENTS AND MAIN RESULTS: Twenty-four patients (37%) had abnormal left ventricular ejection fraction and 56 (86%) had abnormal global longitudinal strain four chamber. Between patients with normal and abnormal left ventricular ejection fraction, we failed to identify a difference in cardiac biomarker levels, vasoactive use, respiratory support needs, or ICU length of stay. Global longitudinal strain four chamber was associated with maximum cardiac biomarker levels. Abnormal global longitudinal strain four chamber was associated with greater odds of any vasoactive use (odds ratio, 5.8; 95% CI, 1.3-25.3; z-statistic, 2.3; p = 0.021). The number of days of vasoactive infusion was correlated with global longitudinal strain four chamber (r = 0.400; 95% CI, 2.4-3.9; p < 0.001). Children with abnormal strain had longer ICU length of stay (4.5 d vs 2 d; p = 0.014). CONCLUSIONS: Our findings suggest strain echocardiography can detect abnormalities in cardiac function in multisystem inflammatory syndrome in children patients unrecognized by conventional echocardiography. These abnormalities are associated with increased use of intensive care therapies. Evaluation of these patients with strain echocardiography may better identify those with myocardial dysfunction and need for more intensive therapy.