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 < or =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.