Infective Endocarditis in Solid Organ and Haematopoietic Stem Cell Transplant Recipients (E-IPA Study): a propensity-score-matched retrospective cohort study.

OBJECTIVES: Infective endocarditis (IE) is rare but severe, and its epidemiology and outcome in solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT) recipients remain poorly described. This study aimed to characterise IE in SOT/HSCT recipients and to compare its features with those of non-transplant patients. METHODS: A multicentre retrospective cohort study was conducted across 27 hospitals in France, including all SOT/HSCT recipients with definite or possible IE, according to the 2023 Duke-ISCVID criteria, between 2007 and 2023. SOT/HSCT recipients were compared with non-transplant controls from two French IE cohorts using 1:1 propensity score matching. Cox proportional hazards models were used to assess 90-day and 1-year all-cause mortality. RESULTS: 262 SOT/HSCT recipients with IE and 1573 controls were included. Among transplant recipients, the most frequent pathogens were Staphylococcus aureus (25%, 66/262), Enterococcus spp. (21%, 55/262), and coagulase-negative staphylococci (CoNS) (16%, 42/262). Microbiological patterns varied according to time since transplantation, with more fungal and CoNS IE within the first year and more streptococcal IE thereafter (p=0.01). After matching, pathogen distribution differed, with fewer streptococcal IE and more Enterococcus spp., CoNS, non-HACEK Gram-negative bacilli, and fungal IE in SOT/HSCT recipients (p<0.001). In multivariable analysis, SOT/HSCT status was independently associated with higher 1-year all-cause mortality (adjusted HR 1.69, 95% CI 1.05-2.72; p=0.029), but not 90-day mortality. CONCLUSIONS: IE in transplant recipients has distinct clinical and microbiological features and is associated with increased 1-year mortality. Time since transplantation may help inform diagnostic evaluation and empirical antimicrobial strategies.