Circulating IL-6 and SAA concentrations measured during the acute phase of SARS-CoV-2 infection were independently associated with long-term cardiovascular events and mortality over a six-year follow-up period.
14.4% of participants experienced the composite cardiovascular endpoint during the six-year follow-up period.
Individuals who experienced adverse outcomes had significantly higher acute-phase IL-6 levels compared with event-free participants.
Individuals who experienced adverse outcomes had significantly higher acute-phase SAA levels compared with event-free participants.
Both IL-6 and SAA independently predicted long-term adverse cardiovascular events after COVID-19 infection.
The study characterized IL-6 and SAA as biomarkers of post-COVID cardiovascular vulnerability measured during the acute inflammatory phase.
This research suggests that the severity of inflammation during a COVID-19 infection — measured by two specific proteins in the blood called interleukin-6 (IL-6) and serum amyloid A (SAA) — may be linked to an increased risk of serious heart problems and death years later. In a study of 97 people who had been infected with SARS-CoV-2, those with higher levels of these inflammatory markers during their acute illness were significantly more likely to experience heart attacks, dangerous heart rhythm problems, or death over the following six years. About 1 in 7 participants (14.4%) experienced one of these serious outcomes during the follow-up period. The two biomarkers appeared to predict different aspects of long-term risk: IL-6 was most strongly linked to death from any cause, while SAA was particularly associated with heart attacks and the overall combined outcome of serious cardiovascular events. Importantly, each biomarker independently predicted these outcomes, suggesting they may capture different aspects of the inflammatory process that can damage the heart and blood vessels over time. This research suggests that a simple blood test taken during a COVID-19 infection could potentially help identify people at higher risk for serious heart problems years down the line. However, the authors caution that the study involved a relatively small number of participants and that these findings are preliminary and hypothesis-generating. Larger studies are needed to confirm these associations before such measurements could be used in clinical practice to guide long-term monitoring or preventive care after COVID-19.
Filev R, Bogov B, Hadjieva R, Kalinov K, Hristova J, Svinarov D, et al.. (2026). Association of Acute-Phase IL-6 and SAA with Cardiovascular Events and Mortality Six Years After COVID-19 Infection: An Observational Cohort Study.. International journal of molecular sciences. https://doi.org/10.3390/ijms27114721