Mitroflow aortic pericardial bioprosthesis--clinical performance.

OBJECTIVE: Advancing life expectancy with the increased prevalence of aortic valve degenerative disease brings the need for an aortic bioprosthesis with excellent haemodynamic performance and comparable durability. The Mitroflow bioprosthesis has been on the worldwide market, except in the United States, since 1982, while the current model (1991) has only recently gained regulatory approval in the latter country. This study was primarily performed to determine the durability of the current Mitroflow bioprosthesis. METHODS: The contemporary Mitroflow bioprosthesis was implanted in 381 patients in three centres. The mean age was 76.4 years (range 53-91 years) and the mean follow-up period was 5.4+/-3.4 years, a total of 2048.7 years of evaluation. Prosthesis-patient mismatch (PPM) was classified by reference effective orifice area index categories: normal > or = 0.85 cm(2) m(-2) (53.9%), mild 0.84-0.76 cm(2) m(-2) (33.9%), moderate < or = 0.75-0.66 cm(2) m(-2) (11.7%) and severe < or = 0.65 cm(2) m(-2) (0.5%). RESULTS: The survival, at 10 years, was 39.9+/-7.9% for 50-69 years, 27.0+/-3.7% for 70-79 years and 16.6+/-4.4% for > or = 80 years (p=0.011). There was a trend (p=0.063) influencing survival for moderate-to-severe PPM. Of the independent predictors influencing survival--moderate-to-severe projected effective orifice area index (pEOAI) (Hazard Ratio (HR) 1.6, p=0.0142) and left ventricular dysfunction (ejection fraction < 35%) (HR 1.9, p=0.0193) were included. The 10-year freedom from structural valve deterioration (SVD) at explant assessing the same age groups as survival was not different (p=0.081). The 10-year actual/actuarial freedom from SVD, at explant was for > or = 60 years--94.4+/-1.4% (85.2+/-3.9%), for > or = 65 years--94.2+/-1.4% (85.0+/-4.0%), for 61-70 years--97.4+/-2.6% (95.7+/-4.3%) and for > 70 years--94.0+/-1.5% (83.2+/-4.6%). CONCLUSIONS: The Mitroflow external mounted, pericardial aortic bioprosthesis with documented excellent haemodynamics (especially for the small aortic root), demonstrates that prosthesis-patient mismatch in moderate and severe categories can essentially be eliminated, with durability performance comparable to other heterograft (porcine and pericardial) bioprostheses.

Mitral valve disease: if the mitral valve is not reparable/failed repair, is bioprosthesis suitable for replacement?

OBJECTIVE: The durability of mitral bioprostheses has long been known to be inferior to aortic bioprostheses. Mitral valve reconstruction/repair is currently recommended for most mitral valve procedures. The choice of prostheses for non-reparable or failed mitral valve repairs has not been specified or given appropriate attention within the literature. The objective of this study is to address the role of bioprostheses in the specific subset of non-reparable or failed repair patients by using the knowledge of the general durability of mitral porcine bioprostheses, inclusive of the Carpentier-Edwards mitral porcine bioprosthesis. METHODS: The CE-SAV was implanted in 1135 patients (1175 operations) for mitral valve replacement (MVR) from 1982 to 2000. The mean age was 65.0+/-12.1 years (range 13-86 years). The mean follow-up was 6.4+/-4.5 years, 7555.9 patient-years and 98.3% complete. The evaluation considered freedom from structural valve deterioration (SVD) and freedom from composites of complications, as well as risk assessment. RESULTS: For the 51-60 year age group, the actual and actuarial freedom from SVD was, at 18 years, 56.0+/-4.1% and 14.7+/-5.8%; for the 61-70 year age group was, at 18 years, 69.6+/-2.6% and 26.5+/-5.9%, respectively. For the >70 group, at 15 years was 92.2+/-2.0% and 69.0+/-9.7%, respectively. There were a total of 256 SVD events with 31 fatalities and 226 reoperations with 10 fatalities (4.42%). The predictors of SVD were age (hazard ratio [HR] 0.98, p=0.0002), concomitant CAB (HR 0.66, p=0.020) and valve size (HR 1.08, p=0.034). The overall actual freedom, at 15-18 years, for >70 age group was, for valve-related reoperation, 94.3+/-1.5%; and for valve-related mortality was 87.8+/-2.3%. CONCLUSIONS: The CE-SAV mitral porcine bioprosthesis cannot be recommended as representative of prosthesis-type of choice for non-reparable or failed repair of native mitral valves for ages 70 years of age. The clinical performance of the CE-SAV is similar to other mitral bioprostheses.