ABSTRACT
BACKGROUND: COVID-19 is a great medical challenge as it provokes acute respiratory distress and has pulmonary manifestations and cardiovascular (CV) consequences. AIMS: This study compared cardiac injury in COVID-19 myocarditis patients with non-COVID-19 myocarditis patients. METHODS: Patients who recovered from COVID-19 were scheduled for cardiovascular magnetic resonance (CMR) owing to clinical myocarditis suspicion. The retrospective non-COVID-19 myocarditis (2018-2019) group was enrolled (n = 221 patients). All patients underwent contrast-enhanced CMR, the conventional myocarditis protocol, and late gadolinium enhancement (LGE). The COVID study group included 552 patients at a mean (standard deviation [SD]) age of 45.9 (12.6) years. RESULTS: CMR assessment confirmed myocarditis-like LGE in 46% of the cases (68.5% of the segments with LGE <25% transmural extent), left ventricular (LV) dilatation in 10%, and systolic dysfunction in 16% of cases. The COVID-19 myocarditis group showed a smaller median (interquartile range [IQR]) LV LGE (4.4% [2.9%-8.1%] vs. 5.9% [4.4%-11.8%]; P <0.001), lower LV end-diastolic volume (144.6 [125.5-178] ml vs. 162.8 [136.6-194] ml; P <0.001), limited functional consequence (left ventricular ejection fraction, 59% [54.1%-65%] vs. 58% [52%-63%]; P = 0.01), and a higher rate of pericarditis (13.6% vs. 6%; P = 0.03) compared to non-COVID-19 myocarditis. The COVID-19-induced injury was more frequent in septal segments (2, 3, 14), and non-COVID-19 myocarditis showed higher affinity to lateral wall segments (P <0.01). Neither obesity nor age was associated with LV injury or remodeling in subjects with COVID-19 myocarditis. CONCLUSIONS: COVID-19-induced myocarditis is associated with minor LV injury with a significantly more frequent septal pattern and a higher pericarditis rate than non-COVID-19 myocarditis.