Comparison of outcomes after aortic valve replacement with a mechanical valve or a bioprosthesis using microsimulation

Background: Mechanical valves and bioprostheses are widely used for aortic valve replacement. Though previous randomised studies indicate that there is no important difference in outcome after implantation with either type of valve, knowledge of outcomes after aortic valve replacement is incomplete. Objective: To predict age and sex specific outcomes of patients after aortic valve replacement with bileaflet mechanical valves and stented porcine bioprostheses, and to provide evidence based support for the choice of prosthesis. Methods: Meta-analysis of published results of primary aortic valve replacement with bileaflet mechanical prostheses (nine reports, 4274 patients, and 25 726 patient-years) and stented porcine bioprostheses (13 reports, 9007 patients, and 54 151 patient-years) was used to estimate the annual risks of postoperative valve related events and their outcomes. These estimates were entered into a microsimulation model, which was employed to calculate age and sex specific outcomes after aortic valve replacement. Results: Life expectancy (LE) and event-free life expectancy (EFLE) for a 65 year old ma