Research: COVID-19 Vaccination Increased the Likelihood of Mortality and Severe Heart Failure

Study authors: this could explain excess mortality in countries with high vaccination coverage.

According to a newly published study by Spanish researchers, COVID-19 vaccination significantly increased the risk of severe heart failure and the likelihood of death from heart attack. The highest likelihood of heart problems was found in people who were both vaccinated and had had the virus.

The aim of a recently published study was to find out whether the occurrence and severity of myocardial infarction may have been influenced by a person's previous COVID-19 vaccination or by the disease itself. To do this, the study looked at myocardial infarction data from a single hospital in Madrid, Spain, between March 2020 and March 2023. A total of 976 heart attack survivors and their medical records were examined. The median age of the patients studied was 64 years and 80% of them were men. The majority, 84%, had been vaccinated with the Pfizer or Moderna mRNA vaccine - 53% had received one dose, 49% had two doses and 25% had also received a booster dose.

The majority of patients, 84%, had been vaccinated with the Pfizer or Moderna mRNA vaccine. Photo: Jan Felix Christiansen/Pixabay.

Analysing the data the authors found that patients who had been vaccinated and had had the virus had a 50% higher risk of death or heart failure than patients who had had the virus but had not been vaccinated against the coronavirus. However, unvaccinated people who had not had the virus were least likely to have a heart attack, with a 90% lower risk of heart attack. The difference persisted even when the odds were adjusted for other risk factors such as smoking, blood pressure, and age. It was also noted that vaccinated patients were more likely to have a very severe heart attack on admission and the association between severity and vaccination was particularly significant in patients younger than 65 years.

The study also found that heart attack patients who were vaccinated and had recovered from Covid had about 31 times more anti-spike protein antibodies than unvaccinated patients who had been infected and recovered. The mRNA vaccines were thought to make the human body produce the spike proteins that were supposed to protect people from the virus. While the efficacy of these vaccines against the virus itself was questionable from the start, the vaccine-driven increase may have caused more inflammation and damage to the cardiovascular system.

„The combination of vaccination and natural SARS-CoV2 infection was associated with the development of severe heart failure and cardiogenic shock in patients with STEMI (ST-segment elevation MI), possibly related to an increased serological response,“ the authors wrote in the study's conclusion.

While the study does not prove that Covic vaccines cause excess mortality or additional cases of heart failure, the authors say the findings may explain why, contrary to the more normal mortality predicted by epidemiologists, excess mortality has worsened after the pandemic, particularly in countries with higher vaccination coverage.