Mild COVID very unlikely to cause lasting heart damage: Study

Mild COVID-19 infection is very unlikely to cause lasting damage to the structure or function of the heart, a new study suggests.

The researchers, including Thomas Treibel from the University College London (UCL), said that the findings should reassure the public, as they relate to the vast majority of people who had Covid-19 infections with mild or no symptoms.

"Disentangling the impact COVID-19 has on the heart has been a challenge. But we're now at the stage of the pandemic where we can really start to get a grip on the longer-term implications COVID-19 has on the health of our heart and blood vessels," said Treibel.

For the study, published in the journal JACC: Cardiovascular Imaging, the research team included 149 healthcare workers.

They identified participants with mild Covid-19 from the COVIDsortium, a study in three London hospitals where healthcare workers had undergone weekly samples of blood, saliva and nasal swabs for 16 weeks.

Six months after a mild infection, they looked at the heart structure and function by analysing heart MRI scans of 74 healthcare workers with prior mild COVID-19 and compared them to the scans of 75 healthy age, sex and ethnicity matched controls who had not previously been infected.

They found no difference in the size or amount of muscle of the left ventricle -- the main chamber of the heart responsible for pumping blood around the body -- or its ability to pump blood out of the heart.

The amount of inflammation and scarring in the heart and the elasticity of the aorta -- which is important for blood to easily flow out of the heart -- remained the same between the two groups.

When the researchers analysed blood samples, they found no differences in the two markers of heart muscle damage -- troponin and NT-proBNP -- six months after mild COVID-19 infection.