The risk of death from a heart attack or failure after COVID-19 is very high within the first 30 days of infection but remains heightened for some time afterwards, new research has revealed.

The large UK Biobank study published online in the journal Heart, linked COVID to a heightened risk of poor cardiovascular health and death, particularly among those whose infection is severe and requiring hospital admission.

Most cardiovascular disease diagnoses, especially atrial fibrillation, VTE (blood clot in a vein), pericarditis, and death from any cause occurred within the first 30 days of infection and among those admitted to the hospital for COVID-19 as the primary reason.

But heightened risk remained beyond 30 days, particularly for heart failure, atrial fibrillation, VTE, pericarditis and all-cause deaths, although to a lesser extent, the observational study showed.

Unsurprisingly, deaths were higher among people with COVID-19 infection: those admitted with the virus as a primary reason were 118 times as likely to die as those who didn't need hospital treatment, while those for whom COVID-19 was a secondary diagnosis were 64 times as likely to die.

"The long-term sequelae of past COVID-19 exposure is emerging as a dominant public health concern. Our findings highlight the increased cardiovascular risk of individuals with past infection, which are likely to be greater in countries with limited access to vaccination and thus greater population exposure to COVID-19," said the researchers.

To reach the conclusion, the researchers drew on 53,613 UK Biobank participants, 17,871 of whom were diagnosed with COVID-19 infection between March 2020 and March 2021, and 35,742 of whom weren't.

Of the 17,871 COVID-19 cases, 2,701 required hospital admission for their infection; 866 were admitted to hospital for another condition; and 14,304 didn't need hospital treatment. All participants were tracked until a cardiovascular problem arose, they died, or until the end of March 2021, providing 141 days of monitoring, on average, but ranging from 32 to 395.

Compared with their matched peers who hadn't caught the virus, those who didn't require hospital admission for COVID-19 infection were nearly 3 times as likely to have a blood clot in a vein (VTE) and more than 10 times as likely to die of any cause.

In a linked editorial, doctors from the Centre for Cardiovascular Science, University of Edinburgh, UK, said that the prothrombotic effects of COVID-19 do raise the question of whether antithrombotic strategies are required to prevent this large excess of events".