People who get sick with Covid are at a higher risk of heart attacks and strokes years after clearing the infection, a major study suggests.

Using data from over 200,000 people from the United Kingdom with an average age of 67 who caught Covid in 2020, researchers found the more sick someone was, the more likely they were to develop heart problems.

Overall, being infected with Covid doubled someone's risk of a heart attack or stroke at least three years after the initial infection. 

And patients who were hospitalized because of the virus were four times more likely to develop cardiovascular disease than those who didn't get it. 

This new research comes as other doctors search for clues as to why fatal heart attacks in people under 45 have been increasing. Some point to the the Covid virus as a cause.

Dr Stanley Hazen, the chair of cardiovascular and metabolic sciences at Cleveland Clinic and co-author of the study, said: 'The results included nearly a quarter million people and point to a finding of global health care importance that may translate into an explanation for a rise in cardiovascular disease around the world.'  

People have been sounding the alarm about this link since early in the pandemic.  

Dr Xand van Tullken, a doctor and TV commentator, experienced this firsthand when he noticed his heart began beating irregularly in March 2020. 

He was sweaty, panicked and breathless, and was rushed into the emergency room. 

There, doctors shocked his chest and put him on medication to get his heart back into it's normal rhythm, saving him from heart failure.  

The previously healthy father of two later shared that he believes he developed this heart condition as a result of Covid. 

The new study, which was published cardiologists from the American Heart Association (AHA) in the journal Arteriosclerosis Thrombosis and Vascular Biology, looked back to these early days of the pandemic. 

It included 10,005 UK-based adults around age 50-86 who tested positive for Covid between February and December 2020, before vaccines were available. 

They compared their findings to over 200,000 other survey repliers who did not have Covid. Doctors followed them for three years after their initial Covid test to see how they fared. 

They found that people who caught the virus were overall more likely to suffer complications related to the cardiovascular system - like heart attack, stroke and cardiac arrest - than those who didn't get sick with the disease. This risk persisted over the three years that the doctors monitored the participants. 

It also held true even when the doctors accounted for conditions that would make a patient more likely to develop heart disease in the first place, like diabetes or older heart disease diagnoses. 

After analyzing the data, doctors found that those who were hospitalized with the virus were four times more likely to develop heart disease than those who never caught the bug.

There are multiple ways that this virus may be causing heart problems, the study authors say. 

For one, when someone gets sick with Covid, it causes inflammation all over the body. 

Research has shown this can put pressure on blood vessels, increasing the risk of blood clots. 

Blood clots can lead to heart attack or stroke, blocking the normal flow of blood. 

In addition, in rare cases, Covid can cause inflammation of the heart muscle itself, causing a life threatening condition called myocarditis, which can damage the organ. 

This can also cause plaques to build up in the heart, leading to a greater likelihood of heart disease. 

Finally, studies have shown that Covid can cause the electrical impulses that control the heart to go haywire - leading to an irregular heart beat. This can cause heart failure and stroke.

Dr Hooman Allaye, a co-author of the study, cautioned that since their findings only looked at people from age 50-86, they can't draw conclusions about how this trend might be appearing in other age groups. 

Yet reports have shown that in the past few years, heart attack rates in young people have been rising, leading some people to point to the virus. 

Dr Susan Cheng, the director of the Institute for Research on Healthy Aging at Smidt Heart Institute, who studied heart attack in young people, suggested these same mechanisms could be at play even in young, healthy bodies. 

Dr Cheng told TODAY: 'There are a lot of things that COVID can do to the cardiovascular system.' 

Her 2022 study found a 30 percent increase in heart attack deaths in people 25 to 44 during the first two years of the pandemic. 

In addition, recent data from the National Center for Health Statistics, which show the rate of heart attack in young people increasing by 66 percent, suggesting the pandemic may have played a role a role.

Dr Cheng said: 'I'd love to say we're ... coming out on the other side and we can think of COVID more so like the common cold. Unfortunately, that is not the case.' 

In addition to looking at overall outcomes, the AHA researchers also looked to see how people's blood types may have affected their outcomes after catching Covid. They found that people with A, B or AB blood types who caught Covid were 65 percent more likely to have a heart attack and stroke than people with O blood types. 

Roughly 55 percent of Americans have a non-O blood type. 

The authors are unsure what could be causing it, but the results suggest something in the O-blood type genes makes people more resilient to the affects of Covid. 

Dr Sandeep Das, the chair of the AHA's Covid-19 cardiovascular disease registry, who was not involved in the study, said: 'This is really fascinating, and I look forward to seeing scientists tease out what the specific pathway may be.'