title: Indexed effective orifice area after mechanical aortic valve replacement does not affect left ventricular mass regression in elderly.
abstract: OBJECTIVE
  After aortic valve replacement, the effects of a small functional prosthesis on the extent and pattern of regression of left ventricular hypertrophy and on clinical outcomes may be less significant in older patients with low cardiac output requirements. The objective of this study was therefore to determine whether patient-prosthesis mismatch affects left ventricular mass regression in the elderly.
  
  
  METHODS
  The population studied was made up of 88 patients over 65 years of age with pure aortic stenosis who underwent mechanical aortic valve replacement. The effective orifice area index was calculated for each patient on the basis of the projected prosthesis in vivo effective orifice area. It was considered a continuous variable and influence of its entire range of values on the extent of left ventricular mass regression was analyzed in a multivariate prediction model.
  
  
  RESULTS
  Even though, in the group with prosthesis-patient mismatch there was a trend for lower postoperative left ventricular mass index (115+/-24 g/m(2) vs 102+/-27 g/m(2), p=0.24) and postoperative peak trans-prosthetic gradients (32+/-9.8 mmHg vs 28.9+/-7.79 mmHg, p=0.35) these differences were not statistically significant. The prevalence of residual left ventricular hypertrophy at follow-up was 50% in the group with patient-prosthesis mismatch and 50% in the group without patient-prosthesis mismatch (p=0.83). In multivariate analysis the only factors associated with indexed left ventricular mass were the follow-up time (p=0.015, r(2)=0.22) and preoperative indexed left ventricular mass (p=0.0012, r(2)=0.11).
  
  
  CONCLUSIONS
  The major finding of our study is that patient-prosthesis mismatch does not affect left ventricular mass regression in patients older than 65 with pure aortic stenosis who underwent mechanical aortic valve replacement. In older patients with low cardiac output requirements, even a small change in the valve effective orifice area after aortic valve replacement with modern efficient mechanical prosthesis, will result in a marked reduction of pressure gradient and this will be associated with a significant regression of left ventricular mass.
authors.affiliation: Division of Cardiac Surgery, St. Andrea Hospital, University of Rome La Sapienza, Via di Grottarossa 1035, Rome 00181, Italy.
authors.forename: Antonino
authors.initials: A
authors.lastname: Roscitano
authors.forename: Umberto
authors.initials: U
authors.lastname: Benedetto
authors.forename: Alfonso
authors.initials: A
authors.lastname: Sciangula
authors.forename: Eusebio
authors.initials: E
authors.lastname: Merico
authors.forename: Filippo
authors.initials: F
authors.lastname: Barberi
authors.forename: Roberto
authors.initials: R
authors.lastname: Bianchini
authors.forename: Euclide
authors.initials: E
authors.lastname: Tonelli
authors.forename: Riccardo
authors.initials: R
authors.lastname: Sinatra
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002302:Cardiac Output; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D015999:Multivariate Analysis; D011474:Prosthesis Design; D012074:Remission Induction; D016896:Treatment Outcome