Covid-19 increases risk of heart conditions up to a year later: Study

People who have had COVID-19 are at increased risk of developing cardiovascular complications within the first month to a year after infection, according to a study conducted in the US.

The study, published in the journal Nature Medicine, found that such complications include disruptive heart rhythms, inflammation of the heart, blood clots, stroke, coronary artery disease, heart attack, heart failure or even death.

The researchers noted that these problems occur even among previously healthy individuals and those who have had mild COVID-19 infections.

"What we are seeing is not good. COVID-19 can lead to serious cardiovascular complications and death," said senior study author Ziyad Al-Aly, an assistant professor at Washington University in the US.

"The heart does not regenerate or easily mend after heart damage. These are diseases that will affect people for a lifetime, Al-Aly said.

The researchers noted that COVID-19 infections have, thus far, contributed to 15 million new cases of heart disease worldwide.

"This is quite significant. For anyone who has had an infection, it is essential that heart health be an integral part of post-acute COVID care," Al-Aly said.

Cardiovascular disease -- an umbrella term that refers to various heart conditions, thrombosis and stroke -- is the leading cause of death in the US and the world, the researchers said.

"For people who were clearly at risk for a heart condition before becoming infected with SARS-CoV-2, the findings suggest that COVID-19 may amplify the risk," said Al-Aly.

"But most remarkably, people who have never had any heart problems and were considered low risk are also developing heart problems after COVID-19," he added.

The researchers analysed de-identified medical records in a database maintained by the US Department of Veterans Affairs, the country's largest integrated health-care delivery system.

They created a controlled dataset that included health information of 153,760 people who had tested positive for COVID-19 sometime from March 1, 2020, through January 15, 2021, and who had survived the first 30 days of the disease.

Very few of the people in the study were vaccinated prior to developing COVID-19, as vaccines were not yet widely available at the time of enrollment, the researchers said.

Statistical modelling was used to compare cardiovascular outcomes in the COVID-19 dataset with two other groups of people not infected with the virus.

These were a control group of more than 5.6 million patients who did not have COVID-19 during the same time frame and another group of over 5.8 million people who were patients from March 2018 through January 2019, well before the virus spread and the pandemic settled in.

The study did not include data involving the virus's Delta and Omicron variants, which began spreading rapidly in the latter half of 2021.

The researchers analysed heart health over a year-long period. Heart disease, including heart failure and death, occurred in 4 per cent more people than those who had not been infected with COVID-19, they said.

"Some people may think 4 per cent is a small number, but it is not, given the magnitude of the pandemic," Al-Aly said.

"That translates to roughly 3 million people in the US who have suffered cardiovascular complications due to COVID-19," he added.

Compared with those in the control groups without any infections, people who contracted COVID-19 were 72 per cent more likely to suffer from coronary artery disease, 63 per cent more likely to have a heart attack and 52 per cent more likely to experience a stroke.

Overall, those infected with the virus were 55 per cent more likely than those without COVID-19 to suffer a major adverse cardiovascular event, which includes heart attack, stroke and death.

"Our findings highlight the serious long-term cardiovascular consequences of having a COVID-19 infection and emphasise the importance of getting vaccinated against COVID-19 as a way to prevent heart damage," Al-Aly said.

"This also underscores the importance of increasing accessibility to the vaccines in countries with limited resources," he added.