Comparative evaluation of biological and mechanical prostheses for aortic valve replacement in a middle-aged population: a population-based cohort study.

BACKGROUND

Current guidelines for aortic valve replacement (AVR) lack consensus on prosthesis selection in middle-aged patients. This study aimed to provide a comprehensive comparison of long-term outcomes following AVR with mechanical versus biological prostheses among middle-aged patients in an Asian population.

METHODS

This retrospective cohort study used Taiwan's national claims database, including patients aged 45-64 years who underwent AVR between 2006 and 2021 across 46 hospitals. Propensity score matching was applied to achieve covariate balance. Risks of all-cause mortality and major adverse prosthesis-related events (major bleeding, ischaemic stroke, aortic valve reoperation, endocarditis and sudden cardiac death) were compared using restricted mean survival time (RMST) and subdistribution HRs (sHRs) to account for competing risks. Subgroup analyses were performed for patients aged 45-54 and 55-64 years.

RESULTS

A total of 1136 matched pairs of patients with biological or mechanical prostheses were included, with follow-up of up to 17 years. In the overall cohort, all-cause mortality did not significantly differ between prosthesis groups. However, patients with biological prostheses experienced fewer major adverse prosthesis-related events (10-year RMST difference: 0.68 years; 95% CI: 0.38 to 0.98; sHR: 0.69; 95% CI: 0.59 to 0.81). In age-stratified analyses, outcomes were comparable between types in patients aged 45-54, whereas biological prostheses were associated with similar survival but fewer adverse events in those aged 55-64.

CONCLUSIONS

Among middle-aged Asian patients undergoing AVR, biological and mechanical prostheses yield similar long-term survival, yet biological prostheses carry a lower risk of major adverse events, especially in those aged 55-64. Opting for biological prostheses at a younger age, potentially starting at age 55, may offer advantages in improving long-term outcomes.