Is there a role for anticoagulation with dabigatran in S. aureus bacteremia? Protocol for the adjunctive treatment domain of the Staphylococcus aureus Network Adaptive Platform (SNAP) randomised controlled trial

Abstract

Introduction: Many patients receive oral anticoagulation for reduced stroke risk in atrial fibrillation or as treatment or prevention of venous thromboembolism. Oral factor Xa inhibitors (oral FXaI, eg, apixaban, edoxaban or rivaroxaban) are commonly prescribed for this indication. Dabigatran, an oral direct thrombin inhibitor, is similarly approved. In vitro and animal model evidence suggests that dabigatran also has direct effects on Staphylococcus aureus virulence and infection. Observational data have shown that dabigatran users are less likely to develop S. aureus bacteremia (SAB), and a small randomised controlled trial showed that dabigatran has anti-S. aureus effects when compared with low molecular weight heparins during bloodstream infection. We seek to answer whether dabigatran is superior to the oral FXaIs in achieving better SAB outcomes among patients who independently require oral anticoagulation. We report the intervention-specific protocol, embedded in an adaptive platform trial.

Methods and analysis: The S. aureus Network Adaptive Platform (SNAP) trial [NCT05137119] is a pragmatic, randomised, multicentre adaptive platform trial that compares different SAB therapies for 90-day mortality rates. For this intervention ('Dabi-SNAP'), patients receiving therapy with an oral FXaI will be randomised to continue as usual or to change to dabigatran as of the next scheduled dose. All subjects will receive standard of care antibiotics and/or antibiotics allocated through other active domains in the platform. As the choice of anticoagulant may not demonstrate large differences in mortality, a ranked composite of death and adverse outcomes (Desirability of Outcome Ranking, or DOOR) was chosen as the primary outcome.

Ethics and dissemination: The study is conditionally approved by the research ethics board of the McGill University Health Centre: identifier 2025-10900. Trial results will be published open access in a peer-reviewed journal and presented at a global infectious disease conference. The trial is registered at clinicaltrials.gov with the identifier NCT06650501.

Trial registration number: NCT0665050.

Keywords: Anti-Bacterial Agents; BACTERIOLOGY; MICROBIOLOGY.

Figure 1. Desirability of Ordinal Outcome Ranking (DOOR).