Excellent Durability of the Mosaic Porcine Aortic Bioprosthesis at Extended Follow Up

BACKGROUND: Biological prostheses are widely employed for aortic valve replacement (AVR). The study aim was to evaluate the performance of the Mosaic porcine bioprosthesis in the aortic position over two decades. METHODS: Between November 1995 and December 2016, a total of 254 patients (194 males, 60 females; mean age 74 ± 9 years) underwent AVR with a Mosaic bioprosthesis at the authors' institution. Among the patients, 14% were aged ≥80 years and 86% had pure or prevalent calcific aortic stenosis. Preoperatively, the mean NYHA functional class was 2.5 ± 1.0. RESULTS: Overall hospital mortality was 5%. A total of 107 late deaths occurred, but only 15 were valve-related (0.72 ± 0.19% per patient-year). Actuarial survival at 15 years was 34 ± 7%. Fourteen embolic episodes occurred, with no cases of bioprosthetic thrombosis; freedom from thromboemboli was 88 ± 4% at 15 years. Eight cases of endocarditis occurred, with a freedom of 95 ± 2% at 15 years. Structural valve deterioration (SVD) was observed in four patients, all of whom were successfully reoperated. Freedom from SVD was 97 ± 2% at 15 years and 96 ± 2% at 20 years. At the last follow up, 23 mm and 25 mm prostheses showed mean gradients of 17 ± 6 mmHg and 15 ± 4 mmHg, respectively. A significant reduction in left ventricular mass was noted in patients with aortic stenosis. CONCLUSIONS: The Mosaic bioprosthesis has shown excellent durability over two decades of clinical use, with a negligible incidence of valve degeneration and need for reoperation. Thus, it may be considered a valid option for AVR, especially in elderly patients.