Imma Perfetto
Cosmos science journalist
An estimated 65 million people live with long COVID, many of whom experience cardiovascular issues such as chest pain and heart palpitations. A small new Australian study suggests chronic inflammation could explain these symptoms.
Long COVID, also known as post-acute sequelae of coronavirus disease 2019 (PASC), is defined by the World Health Organization (WHO) as “the continuation or development of new symptoms 3 months after an initial SARS-CoV-2 infection, with these symptoms lasting for at least 2 months with no other explanation.”
The new study involved 25 participants who reported persistent symptoms more than a year post COVID-19 infection, 11 people whose symptoms did not persist long term, and 14 people who had never had the virus.
“We discovered elevated levels of cytokines, proteins which help control inflammation in the body, in the blood samples of people at about 18 months post-infection with SARS-CoV-2,” says Associate Professor Kirsty Short of the University of Queensland, senior author of the Nature Microbiology study.
They focused on detecting a few cytokines which have , which have previously been reported to be elevated in individuals with long COVID.
“Lab studies showed these trace-level cytokines had a direct effect on the functionality of cardiomyocytes, the cells of the heart responsible for its pump function,” says Short.
“These particular types of cells are fundamental building blocks for our heart, so damaging them can lead to cardiovascular symptoms.”
Short says that, until now, the role of chronic inflammation in cardiovascular symptoms hadn’t been clear, particularly in individuals with symptoms persisting for more than a year after infection.
The researchers acknowledge important limitations of the study, including the limited sample size owing to a focus on individuals with prolonged long COVID.
“It’s only early days and these results require validation in additional patient cohorts, including those infected with more recent SARS-CoV-2 strains,” says Short.
“We’re now curious to know whether our findings could be applied to other symptoms of long COVID such as neurological disease or respiratory disease, as this study actively recruited sufferers with chest pain and/or heart palpitations.
“Despite these limitations, this work offers some important new insights into this complex disease, and hopefully offers opportunities to improve the diagnosis, treatment and understanding of long COVID.”
