Late haemodynamic performance and survival after aortic valve replacement with the Mosaic bioprosthesis

OBJECTIVES: The objective was to evaluate the long-term haemodynamic performance of the Mosaic aortic bioprosthesis. Secondary objectives were to investigate the long-term survival, the rate of aortic valve reoperations, and the rate of prosthesis-patient mismatch and its effect on long-term survival. METHODS: We included all patients who underwent aortic valve replacement with a Mosaic bioprosthesis at our institution between 2002 and 2008. Valve haemodynamics were assessed by transthoracic echocardiography as mean and peak pressure gradients. Patient characteristics and outcomes were collected from charts and national registers. RESULTS: We included 355 patients and echocardiographic evaluation was performed at early follow-up in 340 patients (96%) and at late follow-up in 161 patients (45%). The mean follow-up time was 7.1 (maximum 11.7) years. The unadjusted survival at 1, 5 and 10 years was 92, 79 and 42%, respectively. At the early postoperative echocardiography, the peak pressure gradient was 39.9 mmHg (SD 14.4) and the mean pressure gradient was 21.1 mmHg (SD 7.7) and, on late echocardiography, the peak pressure gradient was 38.6 mmHg (SD 15.6) and the mean pressure gradient was 22.5 mmHg (SD 10.1). Moderate or severe prosthesis-patient mismatch was found in 250 (70%) and 49 patients (14%), respectively, but was not significantly associated with mortality in multivariable analyses. CONCLUSIONS: We found that the Mosaic aortic bioprosthesis had acceptable clinical performance at late follow-up. However, a substantial proportion of patients had high transvalvular gradients or moderate or severe prosthesis-patient mismatch, although neither were significantly associated with long-term survival in our population.