Abstract
OBJECTIVES: In recent years, the use of biological prosthetic valves has increased in patients under 65 years of age. This study evaluated overall survival, major adverse cardiac events and reoperation risk following surgical aortic valve replacement using either mechanical or biological prostheses in patients aged 50 to 65 years, aiming to provide data to support optimal valve selection in this group. METHODS: A registry-based cohort study was conducted using nationwide Austrian health insurance data from 1 January 2010 to 31 December 2020. Patients undergoing isolated surgical aortic valve replacement were classified based on valve type into mechanical or biological groups. The primary outcome was all-cause mortality. Secondary outcomes included major adverse cardiac events, reoperation, stroke, bleeding and survival after reoperation. Outcomes were assessed using Cox or competing risk regression models. Propensity score matching was used to reduce baseline differences. RESULTS: In the study cohort, 1018 patients were categorized to the mechanical and 2743 to the biological group. Patients who received mechanical valves had a significantly lower risk of death compared to those with biological valves (hazard ratio 1.352; P = 0.003). The biological group also had higher risks of major adverse cardiac events (hazard ratio 1.182; P = 0.03) and reoperation (hazard ratio 2.338; P = 0.002). Stroke and bleeding risks were similar between groups. All findings remained significant after propensity score matching. CONCLUSIONS: Among patients aged 50 to 65 years undergoing surgical aortic valve replacement, mechanical valves were associated with improved long-term survival, fewer major adverse events, and a lower need for repeat surgery. These findings suggest a need to re-evaluate the increasing use of biological valves in this age group.