Most people who get COVID recover within a few weeks. But for some, symptoms persist for months – a condition now known as long COVID. While it’s often associated with fatigue, breathlessness and “brain fog”, growing evidence suggests it may also affect something less visible, but potentially more serious: the heart.
In our recent study, we found that people with long COVID had higher risk of developing cardiovascular disease – including cardiac arrhythmias, heart attack and heart failure. Importantly, the increased risks were seen in people who had never been hospitalised during their initial COVID infection.
Much of the early research on long COVID and heart health focused on patients who were hospitalised, particularly those treated in intensive care. These patients often had multiple risk factors for cardiovascular disease such as being overweight and having hypertension or diabetes. This made it difficult to separate the effects of severe acute illness from the long-term effects of the infection.
However, the majority of people who had COVID were never admitted to a hospital – yet many still developed chronic symptoms of so-called long COVID. To explore the potential risks in this much larger group, we focused specifically on patients who had experienced a mild-to-moderate COVID infection which they managed at home.
We used healthcare data from more than 1.2 million adults living in Stockholm, Sweden. Among them, 9,000 were diagnosed by a doctor with long COVID. We then followed up these patients over time and compared occurrence of new cardiovascular disease – including heart attack, heart failure, arrhythmias, stroke and peripheral arterial disease – with people who did not have long COVID and had no previous cardiovascular disease.
After a follow-up period of up to four years, cardiovascular disease was more common among people with long COVID.
Among women with long COVID, 18% experienced some form of cardiovascular event, compared with 8% of women without long COVID. Among men, the corresponding figures were 21% versus 11%.
These results did not substantially differ even when we adjusted analyses for age, socioeconomic status and underlying health status – including conditions such as high blood pressure, diabetes, high cholesterol, obesity, depression, smoking and alcohol consumption which are known risk factors of cardiovascular disease.
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Women with long COVID had more than double the risk of developing cardiovascular disease overall compared with women without long COVID, while men had around a 30% higher risk.
The strongest associations were seen for irregular heart rhythm and coronary heart disease. In women, we also observed an increased risk of heart failure and peripheral arterial disease. However, we did not find an association between long COVID and stroke risk.
Why long COVID might affect the heart
It’s not fully understood why long COVID is associated with cardiovascular disease, but several biological mechanisms have been proposed.
The virus can affect the lining of blood vessels, leading to what is known as endothelial dysfunction. It may also trigger long-lasting inflammation and changes in the immune system. Together, these processes can affect how blood flows through the body and how the heart functions.
There’s also growing evidence that long COVID can disrupt the autonomic nervous system – the automatic mechanisms that control heart rate and blood pressure. This may potentially explain why irregular heart rhythms and conditions such as postural orthostatic tachycardia syndrome (Pots) are more common in long COVID patients.
Another possibility is that long COVID may not necessarily cause entirely new disease, but rather reveal underlying conditions that had not yet been diagnosed. In some cases, symptoms such as chest pain or palpitations may lead to further medical evaluation, increasing the likelihood that cardiovascular disease is detected.
Our findings suggest that long COVID is not simply a transient condition, even among people who were never severely ill during the acute infection. Instead, it may have longer-term implications for cardiovascular health.
At the same time, it’s important to put the results into context. The overall risk of cardiovascular disease remains relatively low at the population level. But the relative increase in risk is meaningful and comparable to that seen with established cardiovascular risk factors such as hypertension or diabetes.
The increased cardiovascular risk in long COVID has also important implications for healthcare. Patients with long COVID – particularly women and younger patients – may benefit from more structured follow-up, including assessment of cardiovascular symptoms and better management of cardiovascular risk factors
It also suggests that long COVID should be included in future strategies for cardiovascular risk assessment and prevention, not only in specialist care but also in primary care settings where most of these patients are managed.
More research is now needed to understand the long-term trajectory of these risks and whether they persist, decrease or increase over time. Future studies should also explore whether early identification and management of cardiovascular symptoms in long COVID could help reduce the risk of more serious complications later on.
As the number of people living with long COVID continues to grow, understanding its broader health consequences will be essential – not only for each patient, but for healthcare systems as a whole.
Artur Fedorowski received funding from the Swedish Heart Lung Foundation.
Axel Carl Carlsson and Pia Lindberg do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
