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

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.