While Covid and influenza are both severe respiratory viruses, they appear to affect cardiac tissue very differently.
Key Takeaways
- Findings give insights into how Covid-19 impacts the body compared to other respiratory viruses
- Data associated with the impact of Covid on the heart has previously been limited to blood biomarkers and physiological measurement
- This international team was able to get deeper insights using actual cardiac tissues
In comparison to the 2009 flu pandemic, Covid has led to more severe and long-term cardiovascular disease, researchers have found, who say their study shows categorically that Covid is not ‘just like the flu’.
University of Queensland researchers say they have discovered how Covid-19 damages the heart, and in this initial study, found Covid-19 damaged the DNA in cardiac tissue.
UQ Diamantina Institute researcher Dr Arutha Kulasinghe says the team found while Covid-19 and influenza are both severe respiratory viruses, they appear to affect cardiac tissue very differently.
“In comparison to the 2009 flu pandemic, Covid has led to more severe and long-term cardiovascular disease, but what was causing that at a molecular level wasn’t known,” Dr Kulasinghe says.
“During our study, we couldn’t detect viral particles in the cardiac tissues of Covid-19 patients, but what we found was tissue changes associated with DNA damage and repair.
“DNA damage and repair mechanisms foster genomic instability and are related to chronic diseases such as diabetes, cancer, atherosclerosis and neurodegenerative disorders, so understanding why this is happening in Covid-19 patients is important.”
Data associated with the impact of Covid on the heart has previously been limited to blood biomarkers and physiological measurement, as obtaining heart biopsy samples is invasive.
This study was able to get deeper insights using actual cardiac tissues collected during autopsies from seven Covid patients from Brazil, two people who died from influenza and six control patients.
UQ’s Professor John Fraser, who established the international Covid-19 Critical Care Consortium, says the findings provide insights into how Covid-19 impacts the body compared to other respiratory viruses.
“When we looked at the influenza cardiac tissue samples, we identified that it caused excess inflammation,” Professor Fraser says.
“Whereas we found Covid 19 attacked the heart’s DNA – probably directly and not just as a knock-on from inflammation.
“Our study has highlighted that the two viruses appear to affect cardiac tissue very differently, which we want to get a better understand of in larger cohort studies.
“What we have categorically shown is that Covid is not ‘just like the flu’.
“This study helps us understand how Covid-19 affects that heart, and that is the first step in working out what treatments might be best to repair that heart.”
The international team included UQ’s Dr Fernando Guimaraes, Professor Gabrielle Belz and Dr Kirsty Short, Ning Liu and researchers from WEHI, as well as the Critical Care Research Group at the Prince Charles Hospital.
The research has been published in Immunology.