In a discovery that could shape future health care for millions, an international research collaboration has uncovered a hidden legacy of COVID-19: accelerated vascular ageing, especially in women.

The study, known as the CARTESIAN project, was published in the European Heart Journal and involved nearly 2,400 participants from 16 countries. Its findings suggest COVID-19 doesn’t simply come and go; it leaves a mark deep within our blood vessels, one that could affect heart health for years.

Imagine your arteries as flexible tubes. In youth, they stretch easily with every heartbeat. As we age, these tubes stiffen, like an old garden hose. But what if something could make them stiffen much quicker? According to researchers, COVID-19 seems to be doing exactly that.

The CARTESIAN study measured this effect using carotid-femoral pulse wave velocity (PWV), a straightforward test. It tracks how quickly blood pressure waves travel between the neck and thigh. Fast waves mean stiff arteries—bad news for the heart.

The researchers divided participants into four groups. First, those who never had COVID-19. Second, people who had COVID-19 but recovered at home. Third, those who were hospitalised but not in intensive care. Last, individuals who ended up in intensive care units. Six months after infection, each group underwent PWV testing.

The results were clear, robust and sobering. Every group that had contracted COVID-19 showed higher PWV readings than those who had never been infected. The difference wasn’t subtle—about 0.4 metres per second faster across the board. For context, this increase equates to about five years of extra vascular ageing for a typical 60-year-old woman.

But the real twist lay in the gender breakdown. Women appeared especially vulnerable. Whether their illness was mild or severe, their PWV scores rose significantly. Non-hospitalised women saw increases on par with those hospitalised, while women who’d battled COVID-19 in intensive care showed dramatic jumps in arterial stiffness—over 1 metre per second above controls, roughly matching seven and a half years of vascular ageing.

Men showed a different pattern. Despite experiencing more severe illness and higher mortality rates during acute COVID-19 episodes, their arteries seemed largely unaffected once recovery began. This sharp contrast surprised many experts.

Why do women experience more pronounced vascular effects after COVID-19? Scientists suspect immune system differences play a role. Women typically mount stronger immune responses than men. While this helps fight off infections more effectively, it might also lead to longer-lasting inflammation or autoimmunity—factors that could damage blood vessels over time.

Another key finding links long-term symptoms to vascular health. Women reporting lingering issues such as fatigue, breathlessness or muscle pain months after infection had even stiffer arteries than those who felt fully recovered. This suggests long COVID isn’t just about how you feel—it may have hidden consequences for your heart and circulation.

Vaccination also made headlines in this study. Women who received at least one jab before their six-month check-up had lower PWV scores than those who remained unvaccinated. In other words, vaccines might not only reduce risk of severe illness but also help protect blood vessels from the long-term effects of COVID-19.

The study didn’t stop at six months. A subgroup of participants returned after a year for repeat testing. Encouragingly, researchers saw stabilisation or even improvement in arterial stiffness among COVID-19 survivors over time. Meanwhile, those who’d never had COVID experienced the expected gradual increase in PWV associated with normal ageing.

What do these numbers mean for everyday life? Quite a lot. Higher arterial stiffness raises the risk of heart attacks, strokes and high blood pressure—a concern for anyone who’s had COVID-19 but particularly for women and those struggling with persistent symptoms.

The implications ripple outwards. Health professionals may need to monitor cardiovascular health more closely in COVID-19 survivors, with special attention paid to women and those suffering from long COVID. Lifestyle measures that support heart health—such as regular exercise, balanced diet and blood pressure management—become even more crucial.

The research itself was meticulous. Scientists adjusted for age, body mass index, smoking status and pre-existing cardiovascular conditions to ensure their findings weren’t skewed by other health factors. They used advanced statistical modelling to account for differences in measurement devices and local recruitment procedures. Sensitivity analyses confirmed their results held up under various scenarios.

Although the study was comprehensive, it isn’t without limitations. Most participants were recruited six months after infection, which means early deaths or severe cases might be underrepresented—a phenomenon known as survivor bias. Controls were mostly hospital staff recruited during pandemic peaks, potentially introducing selection bias. Some mild or asymptomatic infections may have slipped through undetected among controls due to imperfect testing.

There’s also the issue of causality. While the association between COVID-19 and vascular ageing is strong, observational studies like this can’t prove cause and effect beyond all doubt. Confounding factors—especially around vaccination status—may influence outcomes.

Ethnic differences showed up in initial analyses but became less pronounced after COVID exposure. Some ethnic groups typically have lower baseline PWV readings than Caucasians; this advantage seemed to disappear post-infection.

Despite these caveats, comparison with historical controls recruited before 2020 supported the main findings: higher vascular ageing among COVID survivors but not in uninfected individuals.

Experts say the study opens new avenues for research—and new questions for public health. Will new variants or repeat infections cause similar problems? Are these changes in arterial stiffness linked to actual heart attacks or strokes down the line? Can targeted treatments help reverse damage? How do genetic and environmental factors interact with COVID-induced vascular ageing?

For now, awareness matters most. If you’ve had COVID-19—even a mild case—you might carry a hidden risk for future cardiovascular problems. Women should be especially vigilant if they’re still dealing with lingering symptoms months after infection.

Vaccination remains a strong protective measure, not just against acute illness but potentially against long-term complications affecting your arteries. Healthcare systems may need to adapt by integrating vascular health checks into follow-up care for COVID-19 survivors, especially women and those with long COVID complaints.

The science isn’t finished yet, but the message is clear: COVID-19’s impact stretches beyond lungs and immune defences; it touches every artery in the body, sometimes speeding up ageing by years. If heart health is already important, it’s become vital in the wake of this post-pandemic era when many individuals are affected by COVID. The research urges us all to look after our arteries—today and for the future.

As more evidence emerges, experts hope to answer lingering questions and offer better guidance on protecting cardiovascular health post-COVID. Until then, staying informed and proactive is the best prescription.