Cardiac involvement in COVID-19 patients: mid-term follow up by cardiac magnetic resonance imaging

Background: Coronavirus disease 2019 (COVID-19) induces myocardial injury, either direct myocarditis or indirect injury due to systemic inflammatory response. Myocardial involvement has been proved to be one of the primary manifestations of COVID-19 infection, according to laboratory test, autopsy, and cardiac magnetic resonance imaging (CMRI). However, the middle-term outcome of cardiac involvement after the patients were discharged from the hospital is yet unknown. The present study aimed to evaluate mid-term cardiac sequelae in recovered COVID-19 patients by CMRIMethods: A total of 47 recovered COVID-19 patients were prospectively recruited and underwent CMRI examination in this study. The CMRI protocol consisted of black blood fat-suppressed T2 weighted imaging (BB-T2WI), T2 star mapping, left ventricle cine imaging, pre- and post-contrast T1 mapping, and late gadolinium enhancement (LGE). Myocardium edema and LGE were assessed in recovered COVID-19 patients. The left ventricle (LV) and right ventricle (RV) function and LV mass were assessed and compared with normal controls.Results: Finally, 44 recovered COVID-19 patients and 31 normal controls were included in this study. No edema was observed in any patient. LGE was found in 13 patients. All LGE lesions were located in the middle myocardium and/or sub-epicardium with a scattered distribution. Further analysis showed that LGE-positive patients had significantly decreased left ventricle peak global circumferential strain (LVpGCS), right ventricle peak global circumferential strain (RVpGCS), right ventricle peak global longitudinal strain (RVpGLS) as compared to non-LGE patients (p＜0.05), while no difference was detected between the non-LGE patients and normal controls.Conclusion: Myocardium injury existed in about 30% of COVID-19 patients. These patients had peak right ventricle strain that decreased at the 3-month follow-up. Cardiac MRI can monitor the COVID-19-induced myocarditis progression, and CMR strain analysis is a sensitive tool to evaluate the recovery of left ventricle circumferential contraction dysfunction and right ventricular dysfunction.