title: Patient-prosthesis mismatch does not affect survival following aortic valve replacement.
abstract: OBJECTIVE
  Patient-prosthesis mismatch (PPM) has been reported to increase perioperative mortality and reduce postoperative survival in patients undergoing aortic valve replacement (AVR). We analysed the effect of PPM at values predicting severe mismatch on survival following AVR in our unit.
  
  
  METHODS
  Prospectively collected data on 1481 consecutive patients who had undergone AVR with or without coronary artery revascularisation between 1997 and 2005 were analysed. Projected in vitro valve effective orifice area (EOA) and geometric prosthesis internal orifice area (GOA) were evaluated and values were indexed to body surface area (cm(2)m(-2)). PPM was defined as EOAi<0.6 and/or GOAi<1.1. Long-term survival data were obtained from the National Institute of Statistics.
  
  
  RESULTS
  One thousand four hundred and eighteen patients were identified. 67/1418 (4.7%) patients had GOAi<1.1; 122/1418 (8.6%) had EOAi<0.6 and 38 (2.6%) patients exhibited both forms of mismatch. One thousand two hundred and sixty-seven patients (89%) demonstrated no mismatch (reference group). There were 75 in-hospital deaths (overall mortality 5.3%) with no significant difference between the mismatch and the reference groups. Survival data were available for up to 8 years (median 36 months, IQR 6-60 months). There were 160 late deaths (13/143 PPM group vs 147/1198 reference group). The 5-year survival estimate was similar for both groups (83% PPM group; 81% reference group; p=0.47). Cox-hazard analysis identified advanced age as the only predictor of reduced survival (age>80, RR 2.13, 95% CI 1.38-4.586, p=0.004).
  
  
  CONCLUSIONS
  Severe patient-prosthesis mismatch was predicted in 4-10% of patients undergoing AVR but this did not affect in-hospital mortality or mid-term survival.
authors.affiliation: Department of Cardiothoracic Surgery, University Hospital NHS Foundation Trust, Birmingham, UK.
authors.forename: Neil J
authors.initials: NJ
authors.lastname: Howell
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Keogh
authors.forename: Vivien
authors.initials: V
authors.lastname: Barnet
authors.forename: Robert S
authors.initials: RS
authors.lastname: Bonser
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Graham
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Rooney
authors.forename: Ian C
authors.initials: IC
authors.lastname: Wilson
authors.forename: Domenico
authors.initials: D
authors.lastname: Pagano
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery*; D001830:Body Surface Area; D004812:Epidemiologic Methods; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000401:mortality; D016896:Treatment Outcome