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.
Jamieson
William Robert Eric
WR
St. Paul's Hospital & Royal Columbian Hospital, University of British Columbia, 486 Burrard Building, 1081 Burrard Street, Vancouver, BC, Vancouver, BC, Canada V6Z 1Y6. eric.jamieson@vch.ca
Koerfer
Reiner
R
Yankah
Charles A
CA
Zittermann
Armin
A
Hayden
Robert I
RI
Ling
Hilton
H
Hetzer
Roland
R
Dolman
William B
WB
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D001955:British Columbia / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D005858:Germany / Q000453:epidemiology; D006350:Heart Valve Prosthesis / Q000009:adverse effects; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000637:transplantation; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation / Q000706:statistics & numerical data; D016896:Treatment Outcome