Authors: artina Haberecker University Hospital Zürich Esther I Schwarz University of Zurich Peter Steiger University of Zurich Karl Frontzek University of ZurichSeptember 2021 Respiration 101(2):1-11 DOI:10.1159/000518914License CC BY-NC 4.0

Abstract and Figures

Background: Findings from autopsies have provided evidence on systemic microvascular damage as one of the underlying mechanisms of Coronavirus disease 2019 (CO-VID-19). The aim of this study was to correlate autopsy-based cause of death in SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive patients with chest imaging and severity grade of pulmonary and systemic morphological vascular pathology. Methods: Fifteen SARS-CoV-2 positive autopsies with clinically distinct presentations (age 22-89 years) were retrospectively analyzed with focus on vascular, thromboembolic, and ischemic changes in pulmonary and in extrapulmonary sites. Eight patients died due to COVID-19 associated respiratory failure with diffuse alveolar damage in various stages and/or multi-organ failure, whereas other reasons such as cardiac decompensation, complication of malignant tumors, or septic shock were the cause of death in 7 further patients. The severity of gross and histopathological changes was semi-quantitatively scored as 0 (absent), 1 (mild), and 3 (severe). Severity scores between the 2 groups were correlated with selected clinical parameters, initial chest imaging, autopsy-based cause of death, and compared using Pearson χ2 and Mann-Whitney U tests. Results: Severe pulmonary endotheliitis (p = 0.031, p = 0.029) and multi-organ involvement (p = 0.026, p = 0.006) correlated significantly with COVID-19 associated death. Pulmonary microthrombi showed limited statistical correlation, while tissue necrosis, gross pulmonary embolism, and bacterial superinfection did not differentiate the 2 study groups. Chest imaging at hospital admission did not differ either. Conclusions: Extensive pulmonary endotheliitis and multi-organ involvement are characteristic autopsy features in fatal CO-VID-19 associated deaths. Thromboembolic and ischemic events and bacterial superinfections occur frequently in SARS-CoV-2 infection independently of outcome.

Histological vascular and gross pulmonary vascular findings in SARS-CoV-2 positive autopsies. Images demonstrate severe grade of vascular changes (larger involved areas and high number of foci) (a-d), images show mild grade morphological changes (smaller or only scattered areas involved) (e-h). Numerous (a) and only scattered (e) lymphocytes beneath the endothelium. Multiple middle-and small-sized (b and c) and only scattered small-sized peripheral (f, g) fibrin and leucocytic thrombi. Large multiple areas (d) and only small foci (h) of pulmonary hemorrhagic infarction and consolidation. a-g: H & E stain. b (inset): modified Picro-Mallory stain. H&E, hematoxylin and eosin; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2

Figures – available via license: Creative Commons Attribution-NonCommercial 4.0 International

Content may be subject to copyright.