Clinical significance of positive donor blood cultures in the development of infectious complications in heart transplant recipients

Aim. To evaluate the probability of infectious complications in the early postoperative period among heart transplant recipients from donors with positive blood cultures, considering the microbiological profile and levels of systemic inflammatory markers.

Materials and methods. This retrospective study included data from 60 orthotopic heart transplantations performed between August 2023 and December 2024. The results of bacteriological cultures of blood, central venous catheter segments, and myocardial biopsies of explanted hearts were evaluated, along with the levels of C-reactive protein, procalcitonin, fibrinogen, and immunoglobulins (IgA, IgM, IgG). The cohort was subsequently divided into two groups based on the presence of donor bacteremia.

Results. It was established that donor bacteremia is not a predictor of early infectious complications in recipients (OR = 0.97); however, central venous catheter colonization statistically significantly increases the risks of developing donor bacteremia (OR = 4.00). The etiological structure of the isolates was dominated by nosocomial pathogens (S. epidermidis and A. baumannii), while the contamination of explanted heart tissues was independent of the donor’s systemic infection. The group with positive blood cultures exhibited significantly higher concentrations of IgA and IgG (p < 0.001), with no statistically significant intergroup differences in classic inflammatory markers.

Conclusion. Microbial colonization of the central venous catheter is a leading risk factor for the development of donor-derived bacteremia, which is associated with the activation of specific humoral immunity without significant changes in acute-phase markers. Due to the high barrier resistance of the myocardium, systemic donor infection does not lead to graft contamination and, consequently, does not increase the risk of early infectious complications in the recipient.

1. Peghin M., Grossi P.A. Donor-derived infections in solid organ transplant recipients. Current Opinion in Organ Transplantation. 2023, vol. 28, no. 5, pp. 384-390. doi: 10.1097/MOT.0000000000001094.

2. Eldin C., Grossi P.A., Manda V. et al. Updates on Donor-Derived Infection in Solid Organ Transplantation, Report from the 2024 GTI (Infection and Transplantation Group) Annual Meeting. Transpl Int. 2025, vol. 38, pp. 14237. doi: 10.3389/ti.2025.14237.

3. Gardiner B.J., Ison M.G. Donor-derived infections in heart and lung transplant recipients. JHLT Open. 2025, vol. 10, pp. 100376. doi: 10.1016/j.jhlto.2025.100376.

4. Mer M. Central venous catheter-related infection – back to basics. Afr J Thorac Crit Care Med. 2022, vol. 28, no. 1. doi: 10.7196/AJTCCM.2022.v28i1.244.

5. O’Grady N.P., Alexander M., Burns L.A. et al. Guidelines for the Prevention of Intravascular Catheter-Related Infections. Clinical Infectious Diseases. 2011, vol. 52, no. 9, pp. e162-e193. doi: 10.1093/cid/cir138.

6. Mitkovskaya N.P., Grigorenko E.A., Suponenko Z.S. et al. The role of positive donor blood culture in the development of infectious complications in heart transplant recipients in the early postoperative period. Proceedings of the National Academy of Sciences of Belarus, Medical series. 2025, vol. 22, no. 4, pp. 304-313. doi: 10.29235/1814-6023-2025-22-4-304-313. (in Russian).

7. Suponenko Z.S., Yakusheva U.G., Troshina A.M. et al. Infectious complications after orthotopic heart transplantation: current state and prospects. Cardiology in Belarus. 2024, vol. 16, no. 4, pp. 344-360. (in Russian).

8. Manjunath A., Maning J., Tingquing W. et al. Cardiac transplantation with increased-risk donors: Trends and clinical outcomes. International Journal of Cardiology. 2025, vol. 421, pp. 132887. doi: 10.1016/j.ijcard.2024.132887.

9. Larsson D., Flach C. Antibiotic resistance in the environment. Nature Reviews Microbiology. 2022, vol. 20, no. 5, pp. 257–269. doi: 10.1038/s41579-021-00649-x.

10. Krishnan J., Carugati M., Miller R. et al. The tell-tale hearts: Donor-derived invasive fungal infections among orthotopic heart transplant recipients. Medical Mycology Case Reports. 2025, vol. 48, pp. 100702. doi: 10.1016/j.mmcr.2025.100702.