A global systematic review and meta-analysis on the emerging evidence on risk factors, clinical characteristics, and prognosis of multisystem inflammatory syndrome in adults (MIS-A)

Background: The multisystem inflammatory syndrome in adults (MIS-A) has emerged, similar to those in children associated with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) [multisystem inflammatory syndrome in children (MIS-C)]. This review aimed to analyze the risk factors, clinical course, and prognosis of MIS-A.Methods: A comprehensive literature search was conducted using several databases for cases reporting MIS-A from 1 December 2019 till 9 September 2021. The case definitions used to identify potential cases were those recommended by the World Health Organization, Center for Disease Control, and individual country/physician classification. The meta-analysis was performed using Comprehensive Meta-Analysis (CMA) 2.2.027 and Review Manager (RevMan) 5.4.1, employing 95% confidence intervals (CI).Results: Seventy studies were assessed for full-text eligibility, out of which 37 were included. The mean age of the study population was 32.52 +/- 10.29 years. The most common symptoms were fever (89.8%, 95% CI: 77.7-95.7%) and diarrhea (49%, 95% CI: 35.4-62.7%). Ventricular tachycardia (57.1%, 95% CI: 43.1-70.1%) was the most common electro-cardiac abnormality. The most common inflammatory marker was elevated C-reactive protein (89.8%, 95% CI: 77.7-95.7%). Abnormal echocardiogram was the most common imaging test result (commonly, ventricular dysfunction and arrhythmias), while steroids were the most administered treatment. Severe cases had a higher need for vasopressor and inotropic support and antibiotic therapy compared to the non-severe cases. One death was reported due to cardiovascular failure.Conclusion: Our collated findings will help clinicians identify the typical presenting symptoms and optimal management of MIS-A. Further research is required to understand the long-term prognosis and the correlation between coronavirus disease 2019 (COVID-19) and MIS-A to understand its pathogenesis and clinical spectrum.