Incidence of myocarditis among patients recovered from COVID-19 infection identified using cardiac magnetic resonance imaging
Authors: Tugade R , Palileo N , Panelo A , Correa M , Leycano D , Pawhay C , Cosare-San Pedro J 
Published: January 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Coronavirus disease 2019 (COVID-19) has caused significant morbidity and mortality worldwide and has been associated with several cardiac complications including myocarditis. COVID-19 patients with myocardial injury have worse clinical outcomes than those without cardiac involvement. Hence, early detection of myocardial involvement in those who have recovered would be helpful in risk stratification of these patients. Locally, there has been no literature regarding cardiac involvement detected by cardiac magnetic resonance (CMR) imaging among COVID-19 patients. This study aims to report the incidence of patients who developed myocarditis among those who recovered from COVID-19 infection and who underwent CMR imaging in our institution.

Methodology
A single-center retrospective cohort study was performed in our institution. Consecutive patients from January 1, 2020, to December 31, 2021, who were initially referred for cardiac CMR examination due to cardiac symptoms and who met the following inclusion criteria 1) 19 years old and above; 2) with a history of a previously confirmed diagnosis of COVID-19 using reverse transcription-polymerase chain reaction (RT-PCR) swab test; 3) patients were considered recovered by the discharging criteria and 4) underwent CMR imaging for evaluation to rule out myocarditis in our institution. The primary outcome was determining the number of patients with positive and negative conventional MRI findings based on late gadolinium enhancement and edema.

Results
Fifty-four percent (54%) of patients had positive conventional MRI findings indicative of myocarditis (myocardial edema or late gadolinium presence). The most common co-morbid condition remains to be Hypertension (55%), followed by Diabetes Mellitus (17%). Dyspnea, palpitations and chest discomfort were the most commonly reported symptoms in 29 (54%), 24 (44%) and 21 (39%) patients, respectively. Twenty-nine patients (54%) were observed with increased T2 signal or positive LGE. Myocardial edema was found in 9 (31%) patients. Among them, 8 (57%) patients were observed with positive LGE. There was no significant difference of LV and RV systolic function among patients with positive and negative conventional CMR findings.

Conclusion
Myocarditis is one of the cardiovascular complications among patients who recovered from COVID-19, as demonstrated by our cardiac MRI study. Evaluation of the cardiac status of recovered COVID-19 patients needs to be closely monitored, and cardiac MRI may be a sensitive imaging tool to investigate any cardiac involvement further. This study provided local data on those with potential structural changes and cardiac complications aligned with the clinical history, which may be unique in our population after recovering from the disease. Further research with a larger sample size, risk factors, and the intervention to prevent disease progression may need more attention.