Multisystem Inflammatory Syndrome Impact on the Cardiovascular System: Single-Centre Study of Latvia

MIS-C (Multisystem inflammatory syndrome in children) is a hyperinflammatory syndrome caused by the Sars-CoV-2 virus, still an ongoing issue worldwide. MIS-C is associated with an impairment of various organ systems, including the cardiovascular system, and up to 100% of all MIS-C patients have a broad spectrum and severity of symptoms. Identifying MIS-C early and starting therapy is crucial to minimise possible complications and clinical worsening. A prospective cohort study in a single centre was conducted at the Children’s Clinical University Hospital in Latvia from January to December 2021. Patients between the ages of one and seventeen years who met the MIS-C criteria were included in the study. We evaluated the patient’s demographic data, blood pressure, echocardiographic data, ESG data, and cardiac biomarkers such as proBNP and troponin I. Thirty-one patients were included who met the MIS-C criteria. The median age was 8.0 years, and 52% were boys. Of all patients, 77% initially presented with hypotension, and 42% required inotropic support. Treatment in the paediatric intensive care unit (PICU) was required in 58% of patients. Reduced left ventricular ejection fraction was observed in 35% of patients. Mildly decreased ventricular ejection fraction (< 55%) was observed in 19% of cases, and moderate dysfunction (ejection fraction < 45%) in 16% of patients. Twelve per cent of patients received milrinone to improve left heart function. Left heart function significantly improved in all patients during the hospitalisation. In 6% of all patients, coronary artery dilations were observed. All patients had dilation resolution at the time of discharge. The median length of hospitalisation was twelve days, and the median length of PICU stay was three days. Multisystem inflammatory syndrome in children is a significant and potentially life-threatening illness with cardiovascular involvement in 100% of cases. Patients who present primarily with higher ProBNP levels are more likely to have decreased left ventricle ejection fraction, which should be kept in mind when evaluating patients with MIS-C. Overall, patients with MIS-C have a good prognosis, and most cardiovascular changes have been resolved by discharge, but further follow-up and studies are needed to judge the long-term outcome.