Prosthesis-patient mismatch after aortic valve replacement: impact of age and body size on late survival.
BACKGROUND
The purpose of this study was to identify patient subgroups in which prosthesis-patient mismatch most influenced late survival.


METHODS
Over a 12-year period, 1,400 consecutive patients underwent bioprosthetic (933 patients) or mechanical (467) aortic valve replacement. Prosthesis-patient mismatch was defined as prosthetic effective orifice area/body surface area less than 0.75 cm2/m2 and was present with 11% mechanical and 51% bioprosthetic valves.


RESULTS
With bioprosthetic valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 68% +/- 7% mismatch versus 75% +/- 7% no mismatch, p < 0.02) but not older patients (p = 0.47). Similarly, with mechanical valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 62% +/- 11% versus 79% +/- 4%, p < 0.005) but not older patients (p = 0.26). For small patients (body surface area less than 1.7 m2), prosthesis-patient mismatch did not impact survival with bioprosthetic (p = 0.32) or mechanical (p = 0.71) valves. For average-size patients (body surface area 1.7 to 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with both bioprosthetic (p < 0.05) and mechanical (p < 0.005) valves. For large patients (body surface area greater than 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with mechanical (p < 0.04) but not bioprosthetic (p = 0.40) valves.


CONCLUSIONS
Prosthesis-patient mismatch had a negative impact on survival for young patients, but its impact on older patients was minimal. In addition, although prosthesis-patient mismatch was not important in small patients, prosthesis-patient mismatch negatively impacted survival for average-size patients and for large patients with mechanical valves.
Moon
Marc R
MR
Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri, USA. moonm@msnotes.wustl.edu
Pasque
Michael K
MK
Munfakh
Nabil A
NA
Melby
Spencer J
SJ
Lawton
Jennifer S
JS
Moazami
Nader
N
Codd
John E
JE
Crabtree
Traves D
TD
Barner
Hendrick B
HB
Damiano
Ralph J
RJ
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000033:anatomy & histology* / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000601:surgery; D001705:Bioprosthesis; D049628:Body Size; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011474:Prosthesis Design; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome