title: Small "functional" size after mechanical aortic valve replacement: no risk in young to middle-age patients.
abstract: BACKGROUND
  The impact of a valve prosthesis-patient size mismatch is still controversial. In most studies, the inclusion of a large proportion of poorly active old patients with low cardiac output requirements may be misleading, due to the close correlation between trans-prosthetic gradients and cardiac output. The aim of this study was to assess the impact of small "functional" prosthesis sizes in active young to middle-age patients.
  
  
  METHODS
  Eighty-three active patients with a mean age of 46 +/- 8 years and a high health survey questionnaire score were followed for 80 +/- 34 months after isolated aortic valve replacement with a mechanical prosthesis.
  
  
  RESULTS
  Patients with an indexed, Doppler derived, effective orifice area index less than 0.85 cm2/m2 (0.77 +/- 0.1 cm2/m2) showed higher early trans-prosthetic gradients (peak, 34 +/- 11 vs 26 +/- 8 mm Hg; P = 0.001) than patients with a larger effective orifice area index. However, significant regression of the left ventricular mass index and improvement of the left ventricular ejection fraction were observed in both groups at follow-up (119.8 +/- 26 vs 165.2 +/- 38 g/m2 and 128.5 +/- 25 vs 181.8 +/- 50 g/m2; P < 0.001; 58 +/- 6 vs 52 +/- 11% and 58 +/- 7 vs 53 +/- 10%; P < 0.001), with no differences between groups (P = 0.4 and P = 0.7, respectively). At multiple linear regression, the final left ventricular mass index was positively related to the preoperative left ventricular mass index (P = 0.004) and was unaffected by the effective orifice area index (P = 0.4). Symptomatic improvement (New York Heart Association class 1.3 +/- 0.4 vs 2.4 +/- 0.8 and 1.2 +/- 0.4 vs 2.2 +/- 0.8; P < 0.001) and freedom from late cardiac death (93 +/- 3% and 95 +/- 6%) were comparable between groups (P = 0.6 and P = 0.7, respectively).
  
  
  CONCLUSIONS
  Our findings indicate that small "functional" prosthesis sizes with modern mechanical valves may not adversely affect outcomes of aortic valve replacement in young patients with high cardiac output requirements.
authors.affiliation: Department of Cardiac Surgery, Second University of Naples, Naples, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Penta de Peppo
authors.forename: Jacob
authors.initials: J
authors.lastname: Zeitani
authors.forename: Paolo
authors.initials: P
authors.lastname: Nardi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Iaci
authors.forename: Patrizio
authors.initials: P
authors.lastname: Polisca
authors.forename: Ruggero
authors.initials: R
authors.lastname: De Paulis
authors.forename: Luigi
authors.initials: L
authors.lastname: Chiariello
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery; D049628:Body Size; D002302:Cardiac Output; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis / Q000706:statistics & numerical data*; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D012307:Risk Factors