Performance of bioprostheses and mechanical prostheses assessed by composites of valve-related complications to 15 years after aortic valve replacement

Objective: This study was conducted to compare the composites of valve-related complications, namely reoperation, morbidity ( defined as permanent neurologic or other functional impairment), and mortality, between bioprostheses and mechanical prostheses for aortic valve replacement. Methods: Between 1982 and 1998, 2195 bioprostheses were implanted in 2179 patients and 980 mechanical prostheses were implanted in 883 patients. Total follow-up was 16,442 years and 5740 years for bioprostheses and mechanical prostheses, respectively. Eight variables were considered as predictors of risk for the composites of valve-related complications. Results: Linearized rates for valve-related reoperation were 1.3%/ patient-year and 0.3%/ patient-year for bioprostheses and mechanical prostheses ( P <.001), respectively. All age groups were differentiated, except > 70 years. Valve-related morbidity was differentiated for all age groups and overall, for bioprostheses and mechanical protheses, was 0.4 %/patient-year and 2.1%/patient-year, respectively ( P <.001). Overall valve-related mortality was 1.0%/ patient-year for bioprostheses and 0.7%/ patient-year for mechanical prostheses ( P =.018). Age and valve-type were predictive risk factors for reoperation and morbidity, whereas age alone was predictive of mortality. Actual freedom from valve-related reoperation favored mechanical prostheses for all age groups, except 61-70 years and > 70 years. Actual freedom from valve-related morbidity favored bioprostheses in all age groups, except <= 40 years. Actual freedom from valve-related mortality was undifferentiated in patients 51-60, 61-70, and > 70 years. Conclusion: No differences were observed in valve-related reoperation and mortality in patients > 60 years. Comparative evaluation gives high priority for bioprostheses in patients > 60 years based on improved morbidity profile. This evaluation extends this center's recommendation for bioprostheses in aortic valve replacement to include patients < 60 years.