Abstract 3704: Very Long-Term Survival Implications of Valve Replacement with Bioprostheses versus Mechanical Prostheses
Background: Several centers favor replacing diseased native heart valves with bioprostheses rather than mechanical prostheses, even in young adult patients. However, long-term data supporting this approach are lacking. Many believe that as decades pass, young adults with bioprostheses may be exposed to undue cumulative risk from multiple reoperations. We examined the very long-term survival implications of prosthesis selection in a young adult cohort followed for a minimum of 20 years.
Methods: Co-morbid, procedural, and yearly follow-up data were available from 4633 patients who underwent left-heart valve or prosthesis replacement at our institution over the last 35 years. Of these, 1512 patients had 20-year follow-up data, of whom 296 were adults under 50 years of age at their first valve operation. Late outcomes were examined with Cox proportional hazards models.
Results: Twenty-year and 25-year survival of adults under age 50 at first aortic valve replacement (AVR) was 59.9±6.0% and 47.2±7.4%, respectively, in patients implanted with a mechanical prosthesis, and 72.0±4.3% and 64.1±5.8%, respectively, in those with a bioprosthesis. After adjusting for co-morbid factors, these differences were not statistically significant; the hazard ratio associated with bioprosthesis use was 0.8 (95% CI: 0.5, 1.2; P=0.3). For mitral valve replacement (MVR) patients, long-term survival was poorer than after AVR (hazard ratio 1.5; 95% CI 1.1, 2.1; P=0.004), but again no detrimental effect was associated with bioprosthesis use over mechanical (hazard ratio 0.9; 95% CI 0.5, 1.4; P=0.5). In both implant positions, concomitant coronary artery disease (CAD) was the strongest predictor of mortality (hazard ratio 1.9; 95% CI 1.2, 3.0; P=0.01), but even within the subgroup of young adults with CAD, no prosthesis class proved superior to the other.
Conclusions: Selecting a bioprosthesis in young adults does not negatively impact very long-term survival, despite the cumulative risk of reoperation. Lifestyle-based patient preferences should therefore prevail. Concomitant CAD is the main determinant of survival in this age group, but these data do not support the commonly-held notion that CAD should influence the choice of one prosthesis class versus the other.