People with long COVID are at increased risk of developing cardiovascular disease, according to a new study from Karolinska Institutet published in eClinicalMedicine. The results show that the risk of conditions such as cardiac arrhythmias and coronary artery disease is higher even among those who were not hospitalised during the acute infection.

Long COVID has become an increasingly significant health problem worldwide, and a growing number of studies suggest that the condition can lead to secondary cardiovascular diseases. To date, research has mainly focused on people who were hospitalised, whilst the risks for those who stayed at home or were treated at a GP are less well known. In the current study, the researchers investigated how often major cardiovascular events occur in these individuals compared with those without the diagnosis.
Of the just over 1.2 million people aged between 18 and 65 included in the study, around 9,000 had been diagnosed with long COVID, corresponding to 0.7 per cent. Two-thirds of them were women. People who had previously had cardiovascular disease or been hospitalised for COVID-19 were excluded from this group.
During the follow-up period of around four years, people with long COVID were more likely to suffer from cardiovascular disease: 18.2 per cent of women and 20.6 per cent of men experienced some form of cardiovascular event, compared with 8.4 per cent of women and 11.1 per cent of men in the group without long COVID.
When the researchers then adjusted the results for factors such as age, socio-economic status and other known risk factors, the differences remained. Women with long COVID had just over twice the risk of receiving a cardiovascular diagnosis compared with women without long COVID. Men had approximately a third higher risk.
“We found that cardiac arrhythmias and coronary artery disease were more common among both women and men with long COVID. In women, there was also an increased risk of heart failure and peripheral vascular disease. However, no clear association was found between long COVID and stroke,” says lead author Pia Lindberg, a nurse and PhD student at the Department of Medicine, Solna, Karolinska Institutet.
As many people with long COVID never required hospitalisation during their acute infection, there is a risk that secondary conditions may be missed, says Pia Lindberg, pointing out that the results suggest these patients may need to be monitored more systematically.
”Our results show that long COVID can be a risk factor for cardiovascular disease, even in younger people who were previously healthy. This underlines the need for structured follow-up that takes gender differences into account, particularly as cardiovascular disease in women often presents with more diffuse symptoms that can make diagnosis more difficult”, concludes Pia Lindberg.
The study was conducted in collaboration between Karolinska Institutet, Karolinska University Hospital, the Academic Primary Care Centre/Region Stockholm and Uppsala University.
The research was funded by Region Stockholm and the Swedish Heart-Lung Foundation. The researchers state that there are no conflicts of interest associated with the study.