COVID patients of any age risk suffering a heart attack in the first two weeks after contracting the illness, experts have warned.
Medics have now highlighted the importance of vaccination across all age groups.
The virus affects all organs in the body and while most people will over come it within a few days, many people have been left with serious health issues and have had to battle debilitating symptoms.
Researchers in Sweden looked at data from over 86,000 Covid-19 patients.
The team at Umeå University found a three-fold increased risk of acute myocardial infarction and stroke in the first two weeks following Covid-19.
Writing in the The Lancet, the experts said that the results were across all age groups and had been adjusted for known risk factors such as age, gender and socio-economic factors.
Study co-author Ioannis Katsoularis, consultant physician in cardiology at the Department of Public Health and Clinical Medicine explained: "The results indicate that acute cardiovascular complications represent an important clinical manifestation of Covid-19.
"Our results also show how important it is to vaccinate against Covid-19, in particular the elderly who are at increased risk of acute cardiovascular events."
In the UK the elderly and most vulnerable were offered a Covid-19 jab first, as it has been proven that they can prevent hospitalisation and severe infection from the bug.
So far in the UK over 46.8 million people have had their first jab, with 38.3 million having had a second.
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The experts in Sweden did not include patients who had previously experienced a stroke.
Krister Lindmark, a consultant medical doctor in cardiology and a co-author of the study explained: "It would have been difficult to calculate the risk that Covid-19 contributes to acute myocardial infarction and stroke, if individuals with a prior event were included.
"This is because the risk of a recurrent acute myocardial infarction and stroke is increased following a first acute myocardial infarction or stroke."
What is a stroke?
A stroke is a life-threatening brain attack, which occurs when the blood supply to part of your brain is cut off – without blood, the cells in your brain can be killed or suffer damage.
It can change how you think and feel, and cause speech problems or a weakness on one side.
For some, the effects of a stroke can be relatively minor and will fade quickly, but others can be left with problems that leave them dependent on other people.
Around one in eight people who suffer a stroke die within 30 days, so it is vital to get medical assistance as soon as possible – the sooner somebody is treated, the more likely they are to survive.
What are the symptoms:
The experts said that to date, this is one of the biggest studies linking the Covid infection to strokes.
Links to heart swelling had previously been made to the Covid vaccines developed by Pfizer and Moderna.
And now the UK's drugs regulator has updated the safety information to show it is a possible side effect for both.
The Medicines and Healthcare products Regulatory Agency says the conditions is still "extremely rare" and "typically mild".
The inflammation of the heart muscle can damage the organ over time.
Experts say the benefits of getting the jab far outweighs the risks, but it could impact the debate on vaccinating kids.
Both infections and inflammation are known to up the risk of stroke and acute myocardial infarction.
They experts added: "The evidence indicates that acute cardiovascular complications might represent an essential clinical manifestation of Covid-19 and the long-term effects might be a challenge for the future.
"These findings could change clinical practice and warrant a prioritisation of preventive and diagnostic strategies, which can affect treatment and, therefore, reduce the burden of morbidity and mortality in this patient group."