Bioprosthetic vs Mechanical Aortic Valve Replacement in Patients 40 to 75 Years of Age

The choice of bioprosthetic or mechanical surgical aortic valve replacement (AVR) should balance individual valve durability with the potential liabilities of oral anticoagulation.

To inform clinical practice, this study sought to evaluate contemporary, real-world, long-term AVR outcomes from the Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD).

All patients undergoing primary isolated bioprosthetic or mechanical AVR were identified. Patients aged <40 and >75 years with endocarditis, emergency/salvage status, shock, ejection fraction ≤25%, and any prior cardiac surgery were excluded. Validated methodology was applied for linkage to the National Death Index to define longitudinal all-cause mortality (2008-2019). Robust risk adjustment was performed by using age-specific inverse probability weighting and restricted cubic splines to model nonlinear age relationships. Sensitivity analyses excluded pure aortic insufficiency, intermediate/high risk (STS predicted risk of operative mortality >4%), and discontinued valve types.

A total of 109,842 patients underwent bioprosthetic (n = 94,125) or mechanical (n = 15,717) AVR during the study period. After risk adjustment, freedom from all-cause mortality favored mechanical valves in patients aged 60 years and younger. Age group-specific analyses showed that mechanical valves were associated with lower all-cause mortality in all age groups ≤60 years. These results remained consistent across all sensitivity analyses.

In patients aged ≤60 years, mechanical AVR was associated with an independent risk-adjusted survival benefit compared with bioprosthetic AVR. These contemporary 12-year survival data further inform patient and provider shared clinical decision-making regarding prosthetic aortic valves.