Navigating troubled waters: a systematic review of prosthetic valve endocarditis reported cases treated with suppressive antimicrobial treatment.

Objectives: We aimed to characterize suppressive antimicrobial treatment (SAT) for non-surgical candidate patients with prosthetic valve endocarditis (PVE).

Methods: We systematically reviewed PubMed and Embase databases for studies reporting individual data on patients with PVE medically treated for longer than 8 weeks published until the 31^st of June 2024. The review protocol was registered on PROSPERO database [CRD42024529650].

Results: One hundred seventy patients were retrieved from 91 studies. PVE-related death during follow-up occurred in 26 (15.57%) patients, being associated with coagulase-negative staphylococci PVE in multivariate Cox regression model (HR 3.40, 95% CI 1.06 - 10.97, p value = 0.04). Relapse occurred in 15 (8.92%) patients and was similar according to SAT discontinuation (long-rank test p value 0.8). This was confirmed after performing landmark analysis to adjust for survival bias (HR 0.97; 95% CI 0.21 - 4.4, p value 0.98). SAT-related adverse events were reported in 15% of the patients.

Conclusion: Supporting evidence for SAT is low and derived from case reports and case series. SAT seems well tolerated, but clinical effectiveness should be further evaluated due to the relevant mortality rate. In selected cases when SAT discontinuation is considered, close and long-term follow-up is crucial to prevent relapse.