Mitral Valve Surgery for Rheumatic Heart Disease in Indigenous Australians: A 27-Year Cohort Study of Repair Versus...

This study aimed to evaluate long-term outcomes of mitral valve surgery for rheumatic heart disease (RHD) in Indigenous Australians, comparing survival and revision rates between valve repair and replacement, and between mechanical and bioprosthetic prostheses.

We conducted a retrospective analysis of 365 consecutive Indigenous Australian patients who underwent mitral valve surgery for RHD at a single tertiary centre from 1992 to 2023. Patients were grouped by procedure type: mitral valve repair, mechanical replacement, or bioprosthetic replacement. The primary outcomes were all-cause mortality and need for revision surgery. Multivariate Cox regression was used to identify independent predictors of outcomes. Kaplan-Meier survival analysis compared event-free survival between groups.

During a mean follow-up of 8.5±6.0 years, 85 patients (23.3%) died and 59 (16.2%) required revision surgery. No significant difference in all-cause mortality was observed between repair and replacement (p=0.70), or between mechanical and bioprosthetic prostheses (p=0.24). Valve repair was associated with a higher unadjusted risk of revision (p=0.01), but this was not significant after adjustment (hazard ratio [HR] 1.41; p=0.30). Bioprosthetic valves were associated with a significantly increased risk of revision compared with mechanical valves (HR 7.22; p<0.001).

In this cohort of young Indigenous Australians with RHD, mitral valve repair and bioprosthetic valves were associated with increased revision rates but showed no survival advantage over mechanical prostheses. These findings support the consideration of mechanical valves in appropriately selected patients to optimise long-term durability.