Cardio-Pulmonary Histopathology with Clinical Correlations of Deceased Patients with COVID-19: A Case Series in Tehran, Iran.

Background: SARS-CoV-2 may affect vital organs. The present study investigated the histopathology of pulmonary and cardiac tissues with clinical correlation in deceased patients with COVID-19.

Methods: We obtained pulmonary and cardiac tissues from 30 deceased patients with COVID-19 in Tehran, Iran, from January to May 2021. Sampling was performed through a percutaneous needle biopsy. After slide preparation, two expert pathologists studied them. We assessed the correlation between clinical and pathological data by Fisher's exact test.

Results: The mean age of the patients was 73.8±13.4 years, and the male-to-female ratio was 23/7. The most common underlying disease was hypertension (HTN) in 25 patients (83%). Fifty-five tissue samples were achieved, including 28 pulmonary and 27 cardiac samples. Our results showed that all patients (100%) developed diffuse alveolar damage (DAD), and 26 (93%) developed hyaline membrane formation. The most common phase of DAD was the exudative-proliferative phase in 16 (57.1%). Three cardiac samples (11%) revealed myocarditis, and seven (26%) showed cardiomyocyte hypertrophy. In univariate analysis using Fischer's exact test, myocarditis had significant relationships with C-reactive protein (CRP) levels higher than 80 mg/dL (=0.008) and elevated cardiac troponin levels higher than two-fold (=0.01).

Conclusion: COVID-19 can affect the major vital organs. However, only myocarditis had a significant relationship with the circulating levels of inflammatory factors.