Fate of aortic bioprostheses: An 18-year experience.

OBJECTIVE: To report our experience in aortic valve replacement with the Mitroflow (Sorin, Vancouver, Canada) aortic bioprosthesis.

METHODS: We retrospectively reviewed all patients who underwent aortic valve replacement with a Mitroflow bioprosthesis at our institution from January 1994 to December 2011. No exclusion criteria were retained. Patients were followed yearly. Echocardiography follow-up was performed systematically before the hospital discharge and annually by patients' cardiologists.

RESULTS: Seven hundred twenty-eight patients (mean age, 76 ± 6 years; range, 33-91 years) underwent aortic valve replacement with Mitroflow 12A or LX model and were included in this analysis. 30-day mortality for nonemergent isolated aortic valve replacement was 5.5%. Eight patients (1%) underwent reoperation for structural valve deterioration (SVD) and 30 patients (5.8%) presented echocardiographic signs of SVD. Actuarial freedom from reoperation for SVD was 99% ± 0.5% and 95% ± 5% at 10 and 15 years. Actuarial freedom from echocardiographic signs of SVD was 77% ± 5% and 56% ± 11% at 10 and 15 years, respectively. At the univariate analysis, only the mean gradient at discharge (P = .0200), the prevalence of size 19 (P = .0273), and severe patient-prosthesis mismatch (P = .0384) were significantly different in patients developing SVD at follow-up. Freedom from echocardiographic signs of SVD at 8 years were 88% ± 4% and 64% ± 13% in patients with a Mitroflow > 19 and Mitroflow 19, respectively (log-rank test, P = .0056; Wilcoxon test, P = .0589).

CONCLUSIONS: Overall outcomes were satisfactory. However the risk of early SVD seems higher for the Mitroflow size 19. This size should be reserved for applications when annulus enlargement is risky or there is an anatomic contraindication to sutureless or stentless valve.