OBJECTIVES: Anticoagulants reduce the risk of stroke in patients with atrial fibrillation (AF). However, due to various causes, including concerns for bleeding, there is treatment variability, including undertreatment or non-treatment, especially in patients with high bleeding risk. The aim of the GARDENIA registry is threefold, 1) to understand the real-world usage of oral anticoagulants (OAC) in patients with AF and elevated risk of bleeding, 2) to evaluate the factors associated with treatment or non-treatment with OACs and adherence to guideline recommended doses of OACs and 3) to determine the incidence of clinical outcomes in this population in relation to the treatment strategy adopted.

METHODS: GARDENIA is a global, multicentre, prospective, non-interventional study. The registry will aim to enrol up to 10,000 patients with AF or atrial flutter with a CHA₂DS₂-VASc score ≥2 (excluding female) and older age (≥70 years), reduced renal function, concomitant antiplatelet use, or history of clinically relevant bleeding. The registry will initially enrol AF patients with new onset or existing AF who have not been recently treated with OACs or have been deemed inappropriate to receive OACs by the treating physician. Subsequent enrolments will include untreated as well as patients on OACs or other stroke prevention strategies such as left atrial appendage occlusion. The patients enrolled will be followed up for 24 months.

RESULTS: The registry will aim to evaluate (i) treatment persistence, all-cause mortality, risk of bleeding and incidence of stroke and systemic embolism in OAC-treated versus untreated patients (raw and baseline adjusted data) (ii) factors associated with treatment decisions in high-risk patients.

CONCLUSIONS: The registry will provide evidence-based analysis to inform future studies in patients with AF and high-risk of stroke. The findings from this registry will also be used to inform future studies with abelacimab in patients with AF and high-risk of stroke.