Journal of Clinical & Experimental Pathology
Open Access

Abstract

The high incidence of cardiovascular diseases exacerbation and thromboembolic complications in COVID-19 and post-COVID patients provokes an assumption that exposure to SARS-CoV-2 may cause the transformation of stable atherosclerotic plaques into unstable ones. A study of large arteries autopsy specimen from 6 cases of cardiovascular death in post-covid period was carried out. For pathohistological examination, aortic fragments were fixed in 10% neutral formalin and embedded in paraffin. Histological sections were stained with hematoxylin and eosin, picrofuchsin according to the van Gieson method, and alcian blue. Stable atherosclerotic plaques (SAP) had a thick, dense fibrous cap with a large amount of collagen fibers and small lipid core; unstable plaques (UAP) were characterized by the presence of a thinned connective tissue cap, with cracks and rupture areas, and relatively large extracellular lipid deposits. In the zone of UAP in the adventitia, groups of small vasa vasorum (VV) of various diameters with a thickened wall were identified. The wall of VV in SAP had a uniform thickness; deposits of glycosaminoglycans were not detected in their areas. The study of VV in the areas of UAP showed a moderate thickening of their walls due to focal deposition of glycosaminoglycans, with degenerative changes in the endothelium. Through the areas of UAP, there was a mild to moderate adventitial lymphocytic inflammatory infiltrate associated with focal edema of the VV. Endothelitis was observed in the aortic intima, corresponding to location of VV. In these areas, swelling of endothelial cells with polymorphic nuclei was noted. The pathomorphological changes revea;ed were consistent with the assumption that the VV lesion in post- COVID may be a key link in the atherogenesis in terms of the progression of arterial damage.

Biography

Valeria A. Shapkina works at Laboratory of the Microangiopathic Mechanisms of Atherogenesis, Saint Petersburg State University, 199034 Saint- Petersburg, Russia.