One in eight patients hospitalised with Covid also suffered heart damage, new studies have shown – raising fears that the pandemic could fuel a crisis in cardiac services.

British scientists are finding that the virus, considered primarily as a lung infection, is also targeting the heart.

Early results from national studies suggest thousands of people have been left with injuries to their hearts after being treated in hospital for Covid. It is feared the findings could foreshadow an increase in demand for hard-pressed NHS cardiac services. 

Colin Berry, a professor of cardiology and imaging at the University of Glasgow, which is involved in one study, found one in eight patients recovering from the virus showed signs of heart inflammation. 

His team analysed a random sample of 161 recovering patients, 90 per cent of whom had been hospitalised, with one in five needing high-level or intensive care treatment. Around one and two months after discharge, their hearts, lungs and kidneys were scanned.

High incidence of inflammation

Prof Berry, who stressed that the yet to be published paper had not been peer-reviewed, told The Telegraph: “About one patient in eight had evidence of heart inflammation. That is a high incidence.”

Research suggests Covid-associated inflammation of the heart – myocarditis – reduces its ability to pump and causes arrhythmias, rapid or irregular rhythms that trigger dizziness, chest pains and shortness of breath. It is thought it may cause the scarring of the organ or injure valves, affecting its ability to pump efficiently.

“The heart inflammation fits with a bigger picture of illness,” Prof Berry said. “We found that quality of life, in terms of physical and mental health, were lower in patients who had heart inflammation. We also saw damage to kidney function in patients who had inflamed hearts.”

Dr Betty Raman, a British Heart Foundation clinical research fellow at the University of Oxford, said a study of 500  patients found inflammation of multiple organs in those who had required hospital treatment for Covid. 

She used magnetic resonance imaging to study the brains, hearts, livers and kidneys of people taking part in post-hospitalisation studies.

Hospital waiting lists for heart care at record levels

Although her study is ongoing, Dr Raman said a preliminary assessment of 58 patients meant “we are seeing inflammation of multiple organs, the heart and vascular system in particular”.

She added: “The severity of infection during the acute stage of illness is a powerful determinant of whether people get heart problems. Mild infection does not seem to leave damage. But some 10 to 15 per cent of people who have severe infections can develop complications.”

It is thought virus particles that are not eradicated in the acute phase of infection then persist in patients’ hearts, and Dr Raman said: “This may be because the patient’s immune system was not sufficiently strong to do this. It is now still trying to clear the virus completely, and this is causing inflammation.”

Another possibility is that a patient’s immune defences mistakenly identify proteins in the body’s cells as viral cells.

Dr Raman said her research showed that some patients suffer vascular or inflammation damage or both, adding: “This might explain the differences in how the virus affects people in long Covid. The wide range of differing symptoms suggests that there are multiple mechanisms.”

The Office for National Statistics estimates that 1.2 million people in the UK have long Covid symptoms, which can include heart disturbances.

Hospital waiting lists for heart care are at record levels, the British Heart Foundation warned last month. More than 275,000 people are waiting for heart tests and treatment in England.