Background and aim of the study: The Medtronic Intact porcine bioprosthesis is a second-generation porcine bioprosthesis. This study was designed to evaluate results with this valve implanted in the aortic position at 13 years, notably with regard to the risk of structural valve deterioration (SVD).
Methods: A total of 188 patients (mean age 72.0+/-8.2 years; range: 28-89 years), who underwent aortic valve replacement between June 1987 and December 1990, was reviewed.
Results: Operative mortality was 9.0% (n = 17). Mean follow up per patient was 7.2+/-4.2 years (maximum 13.6 years); total follow up was 1,408.4 years. Linearized late mortality rate was 6.8%/patient-year (pt-yr) (n = 96), and the overall survival at 13 years 31.5+/-4.3%. SVD occurred in eight patients (linearized rate 0.57%/pt-yr), and freedom from SVD at 10 and 13 years was respectively 95.8+/-1.9% and 91.0+/-3.3% actuarial, and 97.3+/-1.2% and 95.5+/-1.6% actual. The mean time to onset of SVD was 7.8+/-2.8 years, and was independent of patient age at the time of implantation. Freedom from SVD at 10 and 13 years by age groups was: age < or =60 years, 76.6+/-14.8% and 60.9+/-18.0% actuarial, and 80.0+/-12.6% and 68.6+/-15.1% actual (linearized rate 3.3%/pt-yr); age 61-70 years, 96.3+/-2.6% and 92.4+/-4.5% actuarial, and 96.6+/-2.4% and 94.8+/-2.9% actual (linearized rate 0.37%/pt-yr); and age >70 years, 98.3 1.7% and 95.8+/-3.0% actuarial, and 99.2+/-0.8% and 98.3+/-1.2% actual (linearized rate 0.26%/pt-yr) (p <0.007).
Conclusion: When implanted in the aortic position, the Medtronic Intact porcine bioprosthesis provides a low rate of SVD at 13 years. The prosthesis can be used in the aortic position in subjects aged over 60 years with a low rate of deterioration, similar to that with other second-generation bioprostheses.