Prognosis after aortic valve replacement with a bioprosthesis - Predictions based on meta-analysis and microsimulation

Background-Bioprostheses are widely used as an aortic valve substitute, but knowledge about prognosis is still incomplete. The purpose of this study w as to provide insight into the age-related life expectancy and actual risks of reoperation and valve-related events of patients after aortic valve rep lacement with a porcine bioprosthesis. Methods and Results-We conducted a meta-analysis of 9 selected reports on s tented porcine bioprostheses, including 5837 patients with a total follow-u p of 31 874 patient-years. The annual rates of valve thrombosis, thromboemb olism, hemorrhage, and nonstructural dysfunction were 0.03%, 0.87%, 0.38%, and 0.38%, respectively. The annual rate of endocarditis was estimated at 0 .68% for >6 months of implantation and was 5 times as high during the first 6 months. Structural valve deterioration was described with a Weibull mode l that incorporated lower risks for older patients. These estimates were us ed to parameterize, calibrate, and validate a mathematical microsimulation model. The model was used to predict life expectancy and actual risks of re operation and valve-related events after implantation for patients of diffe rent ages. For a 65-year-old male, these figures were 11.3 years, 28%, and 47%, respectively. Conclusions-The combination of meta-analysis with microsimulation enabled a detailed insight into the prognosis after aortic valve replacement with a bioprosthesis for patients pf different ages. This information will be usef ul for patient counseling and clinical decision making. It also could serve as a baseline for the evaluation of newer valve types.