Long-term Oral Suppressive Antimicrobial Therapy in Infective Endocarditis (SATIE Study): An Observational Study

Background: The role of suppressive antimicrobial therapy (SAT) in infective endocarditis (IE) management has yet to be defined. The objective of this study was to describe the use of SAT in an IE referral center and the patients' outcomes.

Methods: We conducted a retrospective observational study in a French IE referral center (Paris). All patients with IE who received SAT between 2016 and 2022 were included.

Results: Forty-two patients were included (36 male [86%]; median age [interquartile range {IQR}], 73 [61-82] years). The median Charlson Comorbidity Index score (IQR) was 3 (1-4). Forty patients (95%) had an intracardiac device. The most frequent microorganisms were Enterococcus faecalis (15/42, 36%) and Staphylococcus aureus (12/42, 29%). SAT indications were absence of surgery despite clinical indication (28/42, 67%), incomplete removal of prosthetic material (6/42, 14%), uncontrolled infection source (4/42, 10%), persistent abnormal uptake on nuclear imaging (1/42, 2%), or a combination of the previous indications (3/42, 7%). Antimicrobials were mainly doxycycline (19/42, 45%) and amoxicillin (19/42, 45%). The median follow-up time (IQR) was 398 (194-663) days. Five patients (12%) experienced drug adverse events. Five patients (12%) presented with a second IE episode during follow-up, including 2 reinfections (different bacterial species) and 3 possible relapses (same bacterial species). Fourteen patients (33%) in our cohort died during follow-up. Overall, the 1-year survival rate was 84.3% (73.5%-96.7%), and the 1-year survival rate without recurrence was 74.1% (61.4%-89.4%).

Conclusions: SAT was mainly prescribed to patients with cardiac devices because of the absence of surgery despite clinical indication. Five (12%) breakthrough second IE episodes were reported. Prospective comparative studies are required to guide this empirical practice.