Impact of Bacterial Infections in Adult Heart Transplant Recipients: A Single-Center Experience (2017-2024)

Adult heart transplant candidates are increasingly hospitalized while awaiting transplantation, frequently requiring intravenous vasoactive drugs and mechanical circulatory support. These conditions are well-established risk factors for healthcare-associated infections, which may adversely affect early post-transplant outcomes.

To describe the epidemiology, clinical presentation, and microbiological profile of infectious complications diagnosed within 90 days after adult heart transplantation at a tertiary referral center.

A retrospective analysis was conducted including adult patients (>18 years) who underwent heart transplantation between January 2017 and December 2024. Demographic characteristics, use of mechanical circulatory support, early mortality, type of infections, and microbiological findings were evaluated.

A total of 391 adult heart transplant recipients were included; 62% were male, with a mean age of 49 years. Intra-aortic balloon pump support was used in 70% of patients and extracorporeal membrane oxygenation in 10%. Early mortality within 30 days occurred in 12.5% of recipients. Infectious complications were highly prevalent, predominantly occurring within the first four weeks after transplantation. Primary bloodstream infections were the most frequent diagnosis (153 episodes), followed by pneumonia and symptomatic urinary tract infections (71 episodes each). The most commonly isolated pathogens were Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. Notably, Candida parapsilosis accounted for a substantial proportion of bloodstream infection isolates. The infection-per-patient index increased from 0.6 to 0.8 between 2017 and 2020 and to 1.4-1.7 between 2021 and 2024.

Infectious complications are highly prevalent among adult heart transplant recipients, particularly during the early postoperative period. Bloodstream infections predominate, with a microbiological profile strongly influenced by hospital-associated flora, including bacterial and fungal pathogens. These findings reinforce the importance of active surveillance, strict infection prevention strategies, and optimized recipient selection to improve early transplant outcomes.