title: Prosthesis-patient mismatch predicts structural valve degeneration in bioprosthetic heart valves.
abstract: BACKGROUND
  Prosthesis-patient mismatch (P-PtM) after aortic valve replacement results in disturbed valve performance associated with increased pressure gradients. However, it is unknown whether this can be related to future structural valve deterioration (SVD) of the bioprosthesis.
  
  
  RESULTS
  In 564 patients (mean age, 74+/-5 years) receiving an aortic valve bioprosthesis, clinical follow-up (median, 6.1 years; maximum, 16.4 years) was analyzed including echocardiography. SVD was diagnosed in 40 patients (7%) as substantially increased stenosis (n=24) or regurgitation (n=16) of the operated valve over time. When patients with P-PtM (effective orifice area index <0.85 cm(2)/m(2); n=285) developed SVD, it was preferentially of the stenosis type, whereas when patients without P-PtM (n=279) developed SVD, the majority was of the incompetence type (P<0.05). Multivariable analysis including patient- and valve-related variables revealed that P-PtM and label size </=21 were independent predictors of SVD (P=0.04 and P=0.02, respectively). A nonparametric Turnbull estimate analysis showed that SVD is virtually nonexistent for up to 9 years in patients without P-PtM. Thereafter, SVD starts to occur and is mainly of the incompetence-type SVD (79% of cases). In patients with P-PtM, SVD starts to occur after 2 to 3 years after implantation and is mainly of the stenosis-type SVD (81% of cases).
  
  
  CONCLUSIONS
  These data suggest that stenosis-type SVD is an early, P-PtM-related, and thus preventable phenomenon. Incompetence-type SVD is a time-dependent, nonspecific wear damage to bioprosthetic valves, which is not related to P-PtM.
authors.affiliation: Cardiac Surgery, University Clinic Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. willem.flameng@med.kuleuven.be
authors.forename: Willem
authors.initials: W
authors.lastname: Flameng
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Herregods
authors.forename: Monique
authors.initials: M
authors.lastname: Vercalsteren
authors.forename: Paul
authors.initials: P
authors.lastname: Herijgers
authors.forename: Kris
authors.initials: K
authors.lastname: Bogaerts
authors.forename: Bart
authors.initials: B
authors.lastname: Meuris
mesh_terms: D000368:Aged; D001022:Aortic Valve Insufficiency / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D049628:Body Size; D002114:Calcinosis / Q000401:mortality / Q000503:physiopathology; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000706:statistics & numerical data*; D006439:Hemodynamics; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009929:Organ Size; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011475:Prosthesis Failure