title: Factors affecting survival after mitral valve replacement in patients with prosthesis-patient mismatch.
abstract: BACKGROUND
  The purpose of this study was to determine the impact of prosthesis-patient mismatch on long-term survival after mitral valve replacement.
  
  
  METHODS
  From 1992 to 2008, 765 patients underwent bioprosthetic (325; 42%) or mechanical (440; 58%) mitral valve replacement, including 370 (48%) patients older than 65 years of age. Prosthesis-patient mismatch was defined as severe (prosthetic effective orifice area to body surface area ratio <0.9 cm(2)/m(2)), moderate (0.9 to 1.2 cm(2)/m(2)), or absent (>1.2 cm(2)/m(2)).
  
  
  RESULTS
  Multivariate analysis identified nine risk factors for late death including advanced age, earlier operative year, chronic renal insufficiency, peripheral vascular disease, congestive heart failure, nonrheumatic origin, concomitant coronary artery bypass grafting, lower body surface area, and more severe prosthesis-patient mismatch (lower effective orifice area to body surface area ratio; p < 0.05). For bioprosthetic recipients older than 65 years of age, survival at 5 and 10 years was 30% ± 7% and 0% ± 0% with severe mismatch compared with 43% ± 4% and 21% ± 5% for absent or moderate mismatch, respectively (p = 0.05). For mechanical recipients younger than 65 years of age, survival at 5 and 10 years was 77% ± 4% and 62% ± 6% with moderate or severe mismatch compared with 82% ± 3% and 66% ± 4%, respectively, without mismatch (p = 0.08).
  
  
  CONCLUSIONS
  Severe mismatch adversely affected long-term survival for older patients receiving bioprosthetic valves. With mechanical valves, there was a trend toward impaired survival when mismatch was moderate or severe in younger patients. Thus, selection of an appropriate mitral prosthesis warrants careful consideration of age and valve type.
authors.affiliation: Division of Cardiothoracic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Abdulhameed
authors.initials: A
authors.lastname: Aziz
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Lawton
authors.forename: Hersh S
authors.initials: HS
authors.lastname: Maniar
authors.forename: Michael K
authors.initials: MK
authors.lastname: Pasque
authors.forename: Ralph J
authors.initials: RJ
authors.lastname: Damiano
authors.forename: Marc R
authors.initials: MR
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001705:Bioprosthesis; D005260:Female; D006349:Heart Valve Diseases / Q000209:etiology / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D015999:Multivariate Analysis; D018579:Patient Selection; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome