Vaccination against a COVID-19 and predictors of COVID-19 development in patients after heart transplantation: a Russian multicenter observational study
Authors: Simonenko M. A. , Fedotov P. A. , Kostomarov A. N. , Kosmachova E. D. , Kolodina M. V. , Utmanova I. V. , Golovina T. S. , Melnikov I. Yu. , Zubareva I. G. , Gorbunova N. A. , Klimova M. O. , Karpenko M. A. , Sitnikova M. Yu. 
Published: October 2024

Patients after heart transplantation (HT) have a high risk of infectious complications, including hospitalization and death due to SARS-CoV-2 infection. However, both patients with heart failure and heart recipients often face vaccination refusal due to insufficient data on its safety in this population.

Aim. To evaluate the efficacy and safety of vaccination against a coronavirus disease 2019 (COVID-19) in individuals after HT.

Material and methods. This retrospective analysis of a multicenter registry created on the basis of the "Database of patients after heart transplantation depending on the vaccination against a COVID-19" (№ 2022622422, Simonenko M. A., Fedotov P. A.) was performed. It included 47 indicators and blinded results of observation of 367 heart recipients who received post-transplant support from February 2020 to May 2023 and lived in 7 regions of Russia.

Results. Most patients included in the study were men (80%, n=294). The mean age of patients at the time of vaccination was 53±13 years. Immunosuppression was induced in 82,3% of patients and they then received maintenance immunosuppressive therapy with calcineurin inhibitors, mycophenolic acid/ mycophenolate mofetil, or everolimus, and half of them, by the time after HT, received glucocorticosteroids. It is important to note that 67% (n=245) of the recipients included in the analysis did not have COVID-19 before HT, and another 33% (n=122) had COVID-19 after HT without being vaccinated. As of May 2023, almost half of the registry participants (47%; n=174) were vaccinated against COVID-19 using the Gam-Covid-Vac (Sputnik V) vaccine in 94% (n=164) of individuals and Sputnik Light in 6% (n=10). Before HT, immunization was carried out in only 6,5% of the studied subjects. Mild side effects such as subfebrile fever (10%), fever (4%), general weakness (11%), or headache (2%) developed in 17% (n=30) of patients within 24-48 hours after vaccination. In addition, 18% (n=32) of patients in the vaccinated group were subsequently infected with COVID-19, of which only 5 people had a moderate course. After 1,5-2 months, two patients developed post-COVID complications such as exacerbation of bronchial asthma (n=1) and post-COVID alveolitis (n=1), which were stopped by glucocorticosteroid therapy. In the absence of vaccination, the relative risk of COVID-19 compared to vaccinated patients was 2,66 (95% confidence interval: 1,88; 3,75). Vaccination against COVID-19 is associated with a 30,9% reduction in the absolute risk of COVID-19, and to prevent 1 case of COVID-19, 4 heart recipients need to be vaccinated (NNT=3,2).

Conclusion. Vaccination against COVID-19 in heart recipients is safe and associated with a lower incidence of COVID-19 and a milder course of COVID-19 compared to unvaccinated patients. Predictors of COVID-19 infection in the studied sample were male sex, the use of mycophenolic acid/mycophenolate mofetil, and the induction of immunosuppression.