Long-Term Safety and Effectiveness of Mechanical versus Biologic Aortic Valve Prostheses in Older Patients: Results from the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery National Database
Background—There is a paucity of long-term data comparing biologic versus mechanical aortic valve prostheses in older individuals.
Methods and Results—We followed patients aged 65-80 years undergoing aortic valve replacement (AVR) with a biologic (n=24,410) or mechanical prosthesis (n=14,789) from 1991-1999 at 605 centers within the Society of Thoracic Surgeons Adult Cardiac Surgery Database using Medicare inpatient claims (mean, 12.6 years; max, 17 years; min, 8 years), and outcomes were compared using propensity methods. Among Medicare-linked AVR patients (mean age, 73 years), both reoperation (4.0%) and endocarditis (1.9%) were uncommon to 12 years; however, the risk for other adverse outcomes was high, including death (66.5%), stroke (14.1%), and bleeding (17.9%). Compared with those receiving a mechanical valve, bioprosthesis patients had a similar adjusted risk for death (hazard ratio [HR] 1.04; 95% confidence interval [CI] 1.01-1.07), higher risks for reoperation (HR 2.55; 95% CI 2.14-3.03) and endocarditis (HR 1.60; 95% CI 1.31-1.94), and lower risks for stroke (HR 0.87; 95% CI 0.82-0.93) and bleeding (HR 0.66; 95% CI 0.62-0.70). While these results were generally consistent among patient subgroups, bioprosthesis patients aged 65 to 69 years had a substantially elevated 12-year absolute risk of reoperation (10.5%).
Conclusions—Among AVR patients, long-term mortality rates were similar for bioprosthetic versus mechanical valve patients. Bioprostheses were associated with a higher long-term risk of reoperation and endocarditis, but a lower risk of stroke and hemorrhage. These risks vary as a function of a patient's age and comorbidities.
- Received February 12, 2013.
- Accepted March 15, 2013.