Cardiovascular symptoms of PASC are associated with trace-level circulatory cytokines that affect the function of primary human cardiomyocytes

Globally, over 65 million individuals are estimated to suffer from post-acute sequelae of COVID-19 (PASC). A large number of individuals living with PASC experience cardiovascular symptoms (i.e. chest pain and heart palpitations) (PASC-CVS). The role of chronic inflammation in these symptoms, in particular in individuals with symptoms persisting for >1 year after SARS-CoV-2 infection, remains to be determined. Here, we show that compared to individuals with a resolved SARS-CoV-2 infection (and no persistent symptoms), individuals with prolonged PASC-CVS had elevated levels of pro-inflammatory cytokines. However, these cytokines were found to be present in trace amounts, such that they could only be detected with the use of novel nanotechnology. Importantly, these trace-level cytokines had a direct effect on the functionality of primary human cardiomyocytes in vitro. Proteomics analyses demonstrated further differences in PASC-CVS and recovered plasma including increased abundance of complement and coagulation associated proteins.