Comparison of Cardiac Magnetic Resonance Imaging Findings in COVID-19 Myocarditis and Nonspecific Viral Myocarditis

Abstract PURPOSE: This study aimed to compare laboratory, echocardiography, and cardiac magnetic resonance imaging (CMR) findings in patients with coronavirus disease-2019 (COVID-19) associated myocarditis and nonspecific viral myocarditis (NSVM).METHODS: We retrospectively evaluated 25 patients who were considered to have COVID-19-associated myocarditis according to the Lake-Louise criteria and clinical findings. We retrospectively evaluated 41 patients who were accepted as NSVM according to the Lake Louse criteria between January 2016 and March 2020. Late gadolinium enhancement (LGE), ejection fraction, stroke volume, peak ejection rate, and cardiac index data were analyzed for two groups. Echocardiography findings and clinical data were evaluated. Comparisons were made one-way analysis of variance and Student's t-test.RESULTS: LGE was detected in 25 (30%) patients with COVID-19 through CMR examination. LGE was detected most frequently in the inferior segments (mean 2.8 segments) in the patients. Pericardial thickening was observed in 8 (32%) patients. In the NSVM patients, LGE was observed only in the inferior segments in 25 patients, in the lateral–inferior segments in 10 patients, and the septal–inferior segments in 6 patients (mean of 2.4 segments). Pericardial thickening was present in 14 (34%) patients. T2 hyperintensity was not observed. Echocardiography findings were within normal limits in myocarditis groups. There was no statistically significant difference between myocarditis groups' CMR functional data (p = 0.027).CONCLUSION: Functional heart parameters and laboratory findings were similar and normal limits, and no significant difference was observed in imaging features and functional data ​​between NSVM and COVID-19-associated myocarditis.