Background and aim of the study: The study aim was to collect intermediate-term data on the Mosaic bioprosthesis implanted in the aortic position. The device has been in clinical use since February 1994.
Methods: The Mosaic bioprosthesis is a stented porcine aortic valve, which combines a zero pressure differential fixation technique and anti-mineralization treatment with amino oleic acid for improved tissue durability. Between February 1994 and May 1999, 100 patients (49 females, 51 males; mean age at implant 73.4 +/- 7.3 years (range: 31-87 years) underwent aortic valve replacement with the Mosaic prosthesis in our department. Concomitant procedures were performed in 40% of cases. Patients were followed up prospectively at annual intervals; the mean follow up was 2.7 years (total 273.7 patient-years (pt-yr)) and was 100% complete.
Results: Total early mortality (within 30 days) was 3.0%; the late mortality rate was 4.4%/pt-yr and included a valve-related mortality rate of 0.7%/pt-yr. The freedom from event rates at five years were 97.3 +/- 1.9% for permanent neurological, 99.0 +/- 1.0% for transient neurological, 95.9 +/- 3.2 for thrombosed prosthesis, 95.6 +/- 2.2% for anti-thromboembolic-related hemorrhage, 100% for primary valvular leak, 96.9 +/- 3.0% for non-structural dysfunction, 100% for endocarditis, and 92.0 +/- 4.9% for explant. The mean systolic gradients were 15.2, 13.1 and 10.1 mmHg for the 21, 23 and 25 mm valve sizes, respectively.
Conclusion: The clinical and hemodynamic performance of the Mosaic prosthesis was highly satisfactory during the first five years after clinical introduction. Further data will be necessary to confirm long-term durability.