Anticoagulation use in rheumatic heart disease-associated atrial fibrillation: a study of real-world practice in Central Australia

Sonia Sawant; Gabrielle Freedman; Ana Garcia; Sally Terrett; Chinmay Khandkar; Anosh Sivashanmugarajah; Angus Baumann

doi:10.1016/j.ijcha.2025.101711

Anticoagulation use in rheumatic heart disease-associated atrial fibrillation: a study of real-world practice in Central Australia

Int J Cardiol Heart Vasc. 2025 May 30:59:101711. doi: 10.1016/j.ijcha.2025.101711. eCollection 2025 Aug.

Authors

Sonia Sawant^{1

2

3

4}, Gabrielle Freedman¹, Ana Garcia¹, Sally Terrett¹, Chinmay Khandkar^{1

3

5}, Anosh Sivashanmugarajah¹, Angus Baumann^{1

6}

Affiliations

¹ Department of Cardiology, Alice Springs Hospital, Alice Springs, Australia.
² Department of Cardiology, St Vincent's Hospital Sydney, Sydney, Australia.
³ Sydney Medical School, the University of Sydney, Sydney, Australia.
⁴ School of Public Health, Imperial College London, London, United Kingdom.
⁵ Department of Cardiology, Royal Prince Alfred Hospital, Sydney, Australia.
⁶ Flinders University Rural Clinical School, Flinders University, Adelaide, Australia.

Abstract

Background: Rheumatic heart disease (RHD) disproportionately impacts minority groups. Indigenous Australians living in remote areas such as Central Australia account for 3.8% of the population and 92% of RHD cases. A complication of RHD is valvular atrial fibrillation (vAF). Previous studies favour Vitamin K antagonist (VKA) use in vAF over direct oral anti-coagulants (DOACs). However, challenges to VKA use remain. This real-world retrospective observational study aimed to compare clinical outcomes between patients prescribed VKAs or DOACs for vAF in Central Australia over a five-year period.

Methods: Patients with RHD and vAF on the Northern Territory RHD Register in January 2019 were identified and five-year outcome data collected. Patients were grouped and analysed according to prescribed oral anticoagulant therapy in January 2019 (intention to treat (ITT)) or in January 2024/time of event (as-treated analysis (AT)). The primary outcome was major adverse cardiac and cerebrovascular events (MACCE). The safety endpoint was major bleeding.

Results: Of patients with vAF, 49 were included in the ITT analysis and 51 in the AT analysis. The mean age was 61.9 ± 13.9 years and 68.9 % were female. There was no difference in MACCE (25.0 % vs 22.2 %, p = 0.86) or major bleeding (20.0 % vs 11.1 %, p = 0.53) between VKAs and DOACs in the ITT analysis. Findings were similarly non-significant in AT analysis.

Conclusion: This study demonstrates no significant advantage to VKA over DOAC therapy in vAF in a small cohort of RHD patients living in remote Australia. Further investigation is required to optimise treatment strategies in this important group.

Keywords: Anticoagulation; Atrial fibrillation; Rheumatic heart disease; Stroke.