title: Aortic valve replacement with 17-mm mechanical prostheses: is patient-prosthesis mismatch a relevant phenomenon?
abstract: BACKGROUND
  We sought to evaluate the long-term performance of a consecutive cohort of patients implanted with a 17-mm bileaflet mechanical prosthesis.
  
  
  METHODS
  Between January 1995 and December 2005, 78 patients (74 women, mean age=71±12 years) underwent aortic valve replacement with a 17-mm mechanical bileaflet prosthesis (Sorin Bicarbon-Slim and St. Jude Medical-HP). Preoperative mean body surface area and New York Heart Association class were 1.6±0.2 m2 and 2.6±0.8, respectively. Preoperative mean aortic annulus, indexed aortic valve area, and peak and mean gradients were 18±1.6 mm, 0.42 cm2/m2, 89±32 mm Hg, and 56±21 mm Hg, respectively. Patients were divided into two groups, according to the presence (group A, 29 patients) or absence of patient-prosthesis mismatch (group B, 49 patients). Patient-prosthesis mismatch was defined by an indexed effective orifice area less than 0.85 cm2/m2.
  
  
  RESULTS
  Overall hospital mortality was 8.8%. Follow-up time averaged 86±44 months. Actuarial 5-year and 10-year survival rates were 83.7% and 65.3%, respectively. The mean postoperative New York Heart Association class was 1.3±0.6 (p<0.001). Overall indexed left ventricular mass decreased from 163±48 to 120±42 g/m2 (p<0.001), whereas average peak and mean prosthesis gradients were 28±9 mm Hg and 15±6 mm Hg, respectively (p<0.001). Early and long-term mortality were similar between the two groups as well as long-term hemodynamic performance (mean peak gradient was 28 mm Hg and 27 mm Hg in group A and B, respectively, not significant); left ventricular mass regression occurred similarly in both groups (indexed left ventricular mass at follow-up was 136±48 and 113±40 in group A and B, respectively; not significant).
  
  
  CONCLUSIONS
  Selected patients with aortic stenosis experience satisfactory clinical improvement after aortic valve replacement with modern small-diameter bileaflet prostheses.
authors.affiliation: I Division of Cardiac Surgery, IRCCS Policlinico San Donato Hospital, San Donato Milanese, Milan, Italy. agaratti@tiscali.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Garatti
authors.forename: Francesca
authors.initials: F
authors.lastname: Mori
authors.forename: Francesco
authors.initials: F
authors.lastname: Innocente
authors.forename: Alberto
authors.initials: A
authors.lastname: Canziani
authors.forename: Piervincenzo
authors.initials: P
authors.lastname: Gagliardotto
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mossuto
authors.forename: Tiberio
authors.initials: T
authors.lastname: Santoro
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Montericcio
authors.forename: Alessandro
authors.initials: A
authors.lastname: Frigiola
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Menicanti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000150:complications / Q000401:mortality / Q000601:surgery*; D015331:Cohort Studies; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome