title: Mitral valve replacement with the Quattro stentless pericardial bioprosthesis: mid-term clinical and echocardiographic follow up.
abstract: OBJECTIVE
  Preservation of the subvalvar apparatus during mitral valve replacement (MVR) is associated with improved ventricular function and patient outcome. The Quattro valve is a chordally supported stentless mitral valve bioprosthesis that undergoes anticalcification treatment and is sutured to both annulus and papillary muscles heads, thus preserving annuloventricular continuity. The study aim was to assess the mid-term hemodynamic and functional results following MVR using the Quattro valve.
  
  
  METHODS
  Between 1998 and 2005, a total of 76 patients received the Quattro valve at the authors' institution. A competing-risks methodology was used to determine the time-related prevalence of four mutually exclusive end-states: death; subsequent valve removal for dysfunction; subsequent valve removal for endocarditis; and survival without valve reoperation. Serial echocardiograms (n = 321) were collected, and regression models adjusted for repeated measures were used to model the longitudinal progression of the prosthesis mitral valve area (MVA), peak gradient (PG), mean gradient (MG), mitral regurgitation (MR) and ejection fraction (EF) over time.
  
  
  RESULTS
  The median patient age was 33 years, and the most common underlying pathology rheumatic fever (46%). Of the patients, 35 (46%) had undergone a prior mitral surgery. A competing-risks analysis showed that, at 10 years after Quattro implantation, 11% of patients had died without subsequent replacement, 57% underwent valve replacement for dysfunction, 7% for endocarditis, and 26% remained alive without reoperation. Overall, 24 valves were explanted (five for endocarditis and 19 for valve malfunction). On multivariable analysis, risk factors for reoperation were prior mitral surgery (p = 0.03), especially prior MVR (p = 0.04). Serial echocardiographic data showed progressive increases in PG and MR, a decrease in MVA, and stable MG and EF.
  
  
  CONCLUSIONS
  In a fairly young population, the longevity of the Quattro valve was limited by a high risk of endocarditis and reoperation requirement. In addition to valve degeneration, malfunction without structural change was a frequent cause of prosthesis replacement. This may be due to an unpredictable geometric ventricular adaptation to the prosthesis, with subsequent development of prosthesis insufficiency or subvalvar stenosis. Further evaluation is required to identify the best candidates to receive the Quattro bioprosthesis.
authors.affiliation: King Faisal Heart Institute, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. balsoufi@hotmail.com
authors.forename: Bahaaldin
authors.initials: B
authors.lastname: Alsoufi
authors.forename: Maie
authors.initials: M
authors.lastname: Al-Shahid
authors.forename: Cedric
authors.initials: C
authors.lastname: Manlhiot
authors.forename: Mouhamed
authors.initials: M
authors.lastname: Al-Amri
authors.forename: Brian W
authors.initials: BW
authors.lastname: McCrindle
authors.forename: Bahaa
authors.initials: B
authors.lastname: Fadel
authors.forename: Zohair
authors.initials: Z
authors.lastname: Al-Halees
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001705:Bioprosthesis; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D055815:Young Adult