Post-COVID-19 Cardiovascular Disorders and the Molecular Mechanism of NET Formation

Objective: The post-COVID-19 process is not completely understood, as it affects COVID-19 survivors at all levels of disease severity, not all of whom are hospitalized. One of the long-lasting COVID-19 symptom categories, cardiovascular disorders (including acute heart failure, palpitations, hypotension, venous thromboembolic diseases, arrhythmias, myocarditis, and increased heart rate), may derive from a systemic inflammatory response to the viral infection. NETs (neutrophil extracellular traps) that fight invading viruses in extracellular cardiac spaces accumulate due to COVID-19, hyperinflammation and cytokine storms. Our study focuses on cardiovascular disorders as COVID-19 sequelae. To determine the role of NETs in these disorders, we aimed to measure levels of PAD4, MPO, MMP-9, and H3Cit. Methods: In this study, forty people with long-term cardiac complications associated with a history of COVID-19 were recruited along with forty healthy people. Results: We found significant differences in PAD4, H3Cit, and MPO plasma levels between the post-COVID-19 and control groups (p values < 0.05). The expression levels of PAD4 mRNA were lower and MMP-9 mRNA levels was higher in the post-COVID-19 group compared with the control subjects. Conclusion: These findings suggest that PAD4, MPO, MMP-9, and H3Cit are potential biomarkers of NET dysregulation and may cause post-COVID-19 symptoms, especially cardiovascular disorders.