Mild heart muscle damage is more common than expected after the first booster

Temporary mild damage to the heart muscle is more common than previously thought after the first Covid 19 booster vaccination. This is the conclusion of a study by Basel researchers.

An interdisciplinary research team from the University and University Hospital of Basel measured a marker called “cardiac troponin” in the blood of employees of the University Hospital three days after the booster vaccination, as the University of Basel announced on Wednesday. (see Resources). If the amount of troponin goes above the normal range, it indicates damage to the heart muscle.

“We found elevated cardiac troponin levels in a higher proportion of vaccinees than expected,” summarizes cardiologist Christian Müller, who led the study.

The research team found mild, temporary damage to the heart muscle in 22 of the 777 participants (of whom 540 were women). This corresponds to 2.8 percent of the people tested. Based on previous passive observations, the researchers had expected a share of 0.0035 percent, or 35 per 100,000 people vaccinated.

Of the 22 people with troponin levels above the normal range, 20 were women and 2 men. The proportion of women who showed heart muscle cell damage after the booster vaccination was 3.7 percent, in men it was only 0.8 percent. By day 4, half of the women and both men had normal troponin levels in the heart.

So far there is only data based on previous passive observations. These were serious cases of heart muscle inflammation, especially in young men, who required hospital treatment, as Müller emphasizes.

According to Müller, the mild effects found in the study include symptoms such as shortness of breath, fatigue and possibly chest pressure.

According to Müller, it is not yet clear what promotes the damage. The main assumptions are either the higher dose of mRNA in the vaccine or a more violent response of the immune system.

According to current knowledge, the heart muscle cannot regenerate or at least minimally. According to study leader Müller, it is therefore possible that annual vaccinations can lead to mild damage.

The findings of the Basel researchers are still awaiting review by a specialized journal. For Müller, however, the overwhelming benefit of the mRNA vaccines is still undisputed. Their efficient protection is a “medical sensation”.

Without this development, the damage caused by the pandemic would have been “several orders of magnitude higher. The vaccines have saved millions of lives.”

In that regard, those parts of the population that are still skeptical of the mRNA vaccination have not been proved right.

But according to Müller, further improvements are needed with these vaccines. It is now up to the vaccine manufacturers to further optimize the vaccines so as not to damage the heart muscle at best. “In the future, when checking the safety of booster vaccinations, you will also have to take into account the phenomenon of heart muscle cell damage.”

When asked what percentage of people infected with corona suffer damage to heart muscle cells by the virus, Professor Müller answers:

(cpf/sda)