Even people who experienced mild COVID-19 infections that never required hospitalization face significantly elevated risks of cardiovascular disease if they develop long COVID, according to research from Stockholm's Karolinska Institutet.
The study, which followed 1.2 million people aged 18-65 over four years, found that women with long COVID had twice the risk of cardiovascular diagnosis compared to those without long COVID. Men faced a 33% higher risk.
The raw numbers are striking. Among women with long COVID, 18.2% experienced cardiovascular events during the follow-up period, versus just 8.4% among those without long COVID. For men, the rates were 20.6% versus 11.1%.
"Our results show that long COVID can be a risk factor for cardiovascular disease, even in younger people who were previously healthy," said Pia Lindberg, a nurse and PhD student who led the research.
What makes this particularly concerning is that the study specifically focused on people who were never hospitalized during their acute infection. Previous research concentrated on severe COVID cases, but this demonstrates that even mild infections can have serious long-term cardiovascular consequences if long COVID develops.
The conditions most strongly associated with long COVID included cardiac arrhythmias and coronary artery disease in both genders. Women also showed elevated risks for heart failure and peripheral vascular disease. Interestingly, the researchers found no clear association with stroke.
The study drew from Stockholm's MIRACLE-S registry and carefully controlled for age, socioeconomic status, and other cardiovascular risk factors. All participants were previously healthy, with no prior cardiovascular disease or COVID hospitalization.
Lindberg emphasized that "these patients may need to be monitored more systematically," particularly given that many never required hospitalization and may have undetected secondary conditions.
The universe doesn't care what we believe about post-viral syndromes. This is rigorous epidemiological data suggesting that long COVID—affecting approximately 0.7% of this cohort—represents a genuine cardiovascular risk factor that clinicians need to take seriously, even in patients who sailed through their acute infection.
