A review paper exploring the risk of myocarditis in patients suffering from Covid-19 found that less than 5 per cent of the cases studied had any incidence of the condition.

The review paper, a meta-analysis of 17 small-scale reports published in the Journal of the American College of Cardiology (JACC), found that either through endomyocardial biopsy or from tissue taken at autopsy, 4.5 per cent of cases had “some evidence” of myocarditis.

Myocarditis is an inflammation of the heart muscle, often related to a recent viral infection, and so the link between the Covid-19 pandemic and the potentially fatal condition was one that has been studied since postmortem reports were filed in Wuhan.

Several small scale studies found evidence of myocarditis in a small number of people who had tested positive for the virus, but more data was needed to find out how prevalent it was overall.

There were some complications noted in the report. Given that it was an analysis of several small reports, the methodology for analysis was not always the same, which meant that the nature and extent of myocarditis even in the 4.5 per cent of cases was uncertain.

The review also focused on the use of endomyocardial biopsy in testing for myocarditis, concluding that it should be used only for worst-case scenarios such as heart failure after a confirmed Covid-19 infection.

Given the still-limited amount of studies, more data will be needed to see if the disease manifests differently in young people, as many of the cases studied were from older patients.