(215) Longitudinal Outcomes of Children Diagnosed With MIS-C: Report From a Single Center in Pakistan

Introduction: Emerging epidemiological data globally on MIS-C following COVID-19 classifies the disease into three main phenotypes, including Kawasaki disease (KD), viral myocarditis (VM), and toxic shock syndrome (TSS) with atypical cardiac involvement. Our aim is to determine longitudinal cardiac outcomes of children admitted with multisystem inflammatory syndrome in children (MIS-C) at a tertiary care center in Pakistan.

Methods: We conducted a single-center retrospective analysis of children admitted to a tertiary care pediatric unit in Pakistan fulfilling the World Health Organization (WHO) criteria for MIS-C from April 2020 to March 2022 and later followed up in cardiology clinics at 2 weeks, 3 months, 6 months, 1 year, and 2 years. Cardiac parameters including valvulitis, echocardiography, and global longitudinal strain, were monitored following American Society of Echocardiography guidelines. We defined LV systolic dysfunction by GLS <-17%. We analyzed data using frequency, mean, median and interquartile range (IQR) on STATA 14.0.

Results: A total of 51 children were included. Majority presented with viral myocarditis 21(41.2%) and toxic shock syndrome 17(33.3%) phenotypes. The cardiovascular system was the most commonly involved system 27(52.9%), and most patients had inflammation and myocardial injury, including increased ferritin [1169 (534.75-1704.5)], C-Reactive Protein [83.0 (24.0-175.0)], lactate dehydrogenase [468.0 (365.0-1270.0)], pro-BNP [8656.0 (2538.0-31166)], and troponins [0.157 (0.025-2.0)]. Decreased left ventricular ejection fraction (LVEF) in 30(58.8%), global longitudinal strain in 17(33.3%), valvulitis 38(74.5%), pericardial effusion 23(45.1%), and coronary artery dilation in 3(5.9%) patients were the positive findings on echocardiography done at admission, with the median LVEF and GLS being 55.5(41.0-62.0) and -14(-16--12) respectively. In most patients, LVEF normalized by discharge, GLS normalized by 3 months, and pericardial effusions and valvulitis resolved by 12 months. Intensive care unit (ICU) care was required in 42(82.4%) patients, and 6(11.8%) deaths were reported overall with no death in the follow-up period, related to MIS-C.

Conclusions: Our study highlights that cardiac outcomes in children with MIS-C in Pakistan are encouraging with no long-term damaging sequelae.