Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes coronavirus disease 2019, but no inflammatory cells, (COVID-19) was detected in the myocardium of patients who had died from the disease, according to a study published in JAMA Cardiology.
The cardiac tissues of 39 consecutive autopsies performed in Germany between April 8 and April 18, 2020 were examined. All patients tested positive for COVID-19 by pharyngeal swab tests. Gene expression and histological analyses were conducted on 2 left ventricle tissue samples for each autopsy.
The patients had a median age of 85 years (interquartile range [IQR], 78-89 years) at time of death and 59% were women. The cause of death was pneumonia in 89.7% of patients. Other causes of death were necrotizing fasciitis, bacterial bronchitis, cardiac decompensation with prior heart failure, and undetermined. Coronary artery disease (82.0%), hypertension (43.6%), and diabetes (17.9) were highly prevalent in those patients.
No COVID-19-infected cells were detected in the myocardium for 38.5% of autopsies. Of autopsies with viral presence in the myocardium, 33.3% had fewer than 1000 copies per μg of RNA. Of the 5 autopsies with the highest viral load, the median copy number was 135,584 (IQR, 84,949-474,675) per μg of RNA.
Relative gene expression of tumor necrosis growth factor α, interferon γ, chemokine ligand 5, and interleukin -6, 8, and 18 differed in myocardia with the highest viral load vs those without SARS-CoV-2 infection: (rank sum, P <.01).
The amounts of cluster of Differentiation (CD)3, CD68, and CD45RO were comparable in myocardial tissue samples from patients with high vs no SARS-CoV-2 viral load (P =.15).
No massive cell infiltrates or necrosis were observed, indicating the absence of myocarditis. Viral presence was not associated with an infiltration of mononuclear cells.
A limitation of this study is the advanced age of patients at the time of death.
“Overt fulminant myocarditis has been reported in isolated patients with SARS-CoV-2 infection. However, the current data indicate that the presence of SARS-CoV-2 in cardiac tissue does not necessarily cause an inflammatory reaction consistent with clinical myocarditis,” noted the study authors. “The long-term consequences of this cardiac infection requires further investigation.”
Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.
Lindner D, Fitzek A, Bräuninger H, et al. Association of cardiac infection with SARS-CoV-2 in confirmed COVID-19 autopsy cases. [Published online July 27, 2020] JAMA Cardiol. doi:10.1001/jamacardio.2020.3551