Long-term results of the Medtronic Mosaic porcine bioprosthesis in the aortic position

Abstract

Objective: We addressed the long-term results of the Medtronic Mosaic porcine prosthesis in the aortic position.

Methods: From 1994 to 2004, 1007 Mosaic valves were used for aortic valve replacement. The data were prospectively collected, retrospectively analyzed, and stratified according to patient age at surgery (group 1, <70 years; group 2, 70-75 years; group 3, 76-80 years; and group 4, >80 years), using both actual (cumulative risks) and actuarial methods.

Results: Operative mortality was 5% (valve related in 14%). Globally, 8122.17 patient-years were available (average follow-up, 8.5 ± 3.9 years; 99.8% complete). Overall, survival at 15 years was lower among the elderly strata (P < .0001). Freedom from structural valve deterioration (SVD) was 95.1% (actual) and 86.3% (actuarial; 24 SVD events). Survival free from SVD was lower in group 1 (P = .003) but comparable among the other groups. Overall freedom at 15 years from the composite endpoint (any valve-related adverse events) was 82% (actual) and 71.3% (actuarial). No meaningful intergroup differences were found in survival free from the composite endpoint (P = .9) or freedom from valve-related mortality (P = .8). Younger patients at surgery did not show accelerated degeneration. No relationship could be established between prosthetic size and SVD.

Conclusions: The implantation of a bioprosthesis in patients aged 70 years or older remains fully justified. The rate of SVD was higher in younger patients, mainly owing to their greater life expectancy. Patients younger than 70 can receive a bioprosthesis, provided that the correct information regarding the expected durability has been provided. This might be better accomplished through the actual methodology.