Patients with heart failure (HF) who received two doses of COVID mRNA vaccines were not more likely to have worsening disease, venous thromboembolism, or myocarditis within 90 days than similar unvaccinated patients, in a case-control study in Denmark.
Moreover, in the 90 days after receiving the second shot, vaccinated patients were less likely to die of any cause, compared with unvaccinated patients during a similar 90-day period.
Caroline Sindet-Pedersen, PhD, Herlev and Gentofte Hospital, Hellerup, Denmark, and colleagues presented these findings at the annual congress of the European Society of Cardiology.
Major risk is not receiving vaccine
These results “confirm that the major risk for patients with HF is not receiving vaccination for COVID-19,” Marco Metra, MD, who was not involved with this research, said in an interview.
Dr. Marco Metra
Dr. Metra was coauthor of an ESC guidance for the diagnosis and management of cardiovascular disease during the COVID-19 pandemic, published online ahead of print November 2021 in the European Heart Journal.
The guidance explains that patients with HF are at increased risk for hospitalization, need for mechanical ventilation, and death because of COVID-19, and that vaccination reduces the risk for serious illness from COVID-19, Dr. Sindet-Pedersen and colleagues explained in a press release from the ESC.
However, “concerns remain,” they added, “about the safety of the SARS-CoV-2 mRNA vaccines in heart failure patients, due to a perceived increased risk of cardiovascular side effects.”
The study findings suggest that “there should be no concern about cardiovascular side effects from mRNA vaccines in heart failure patients,” Dr. Sindet-Pedersen and colleagues summarized.
The results also “point to a beneficial effect of vaccination on mortality” and “indicate that patients with HF should be prioritized for COVID-19 vaccinations and boosters,” they added.
“There are ongoing concerns about the safety of COVID-19 vaccination in fragile patients and patients with heart failure,” said Dr. Metra, professor of cardiology and director of the Institute of Cardiology of the Civil Hospital and University of Brescia (Italy).
“These concerns are not based on evidence but just on reports of rare side effects (namely, myocarditis and pericarditis) in vaccinated people,” he added.
Dr. Metra also coauthored a position paper on COVID-19 vaccination in patients with HF from the Heart Failure Association of the ESC, which was published online October 2021 in the European Journal of Heart Failure.
“The current study,” he summarized, “shows a lower risk of mortality among patients vaccinated, compared with those not vaccinated.
“It has limitations,” he cautioned, “as it is not a prospective randomized study, but [rather] an observational one with comparison between vaccinated and not vaccinated patients with similar characteristics.
“However, it was done in a large population,” he noted, “and its results confirm that the major risk for patients with HF is not receiving vaccination for COVID-19.”
95% of patients with HF in Denmark double vaccinated
The group did not analyze the types of all-cause death in their study, Dr. Sindet-Pedersen clarified in an interview.
Other studies have shown that vaccines are associated with improved survival, she noted. For example, bacillus Calmette-Guérin vaccines and the measles vaccines have been linked with a decreased risk for nonspecific mortality in children, and influenza vaccines are associated with decreased all-cause mortality in patients with HF.
The rates of vaccination in this study were much higher than those for patients with HF in the United States.
In a study of 7,094 patients with HF seen at the Mount Sinai Health System between January 2021 and January 2022, 31% of patients were fully vaccinated with two doses and 14.8% had also received a booster, as per Centers for Disease Control and Prevention guidance. However, another 9.1% of patients were only partially vaccinated with one dose, and 45% remained unvaccinated by January 2022,
In the current study, “the uptake was very high,” Dr. Sindet-Pedersen noted, that is, “95% of the prevalent heart failure patients in 2021 received a vaccine.”
“It might be that the last 5% of the patients that did not receive a vaccine were too ill [terminal] to receive the vaccine,” she speculated, “or that was due to personal reasons.”
The researchers identified 50,893 patients with HF who were double vaccinated in 2021 and they matched them with 50,893 unvaccinated patients with HF in 2019 (prepandemic), with the same age, sex, HF duration, use of HF medications, ischemic heart disease, cancer, diabetes, atrial fibrillation, and admission with HF within 90 days.
Almost all patients in the vaccinated group received the Pfizer/BioNTech mRNA vaccine (92%) and the rest received the Moderna mRNA vaccine (8%), in 2021.
The patients had a mean age of 74, and 64% were men. They had HF for a median of 4.1 years.
During the 90-day follow-up, 1,311 patients in the unvaccinated cohort (2.56%) and 1,113 patients in the vaccinated cohort (2.23%) died; there was a significantly lower risk for all-cause death in the vaccinated cohort versus the unvaccinated cohort (–0.33 percentage points; 95% CI, –0.52 to –0.15 percentage points).
The risk for worsening heart failure was 1.1% in each group; myocarditis and venous thromboembolism were extremely rare, and risks for these conditions were not significantly different in the two groups.
The researchers and Dr. Metra declared they have no relevant financial disclosures. Dr. Metra is editor-in-chief of the European Journal of Heart Failure and senior consulting editor of the European Heart Journal.
A version of this article first appeared on Medscape.com.