title: Incidence of prosthesis-patient mismatch in patients receiving mitral Biocor® porcine prosthetic valves.
abstract: BACKGROUND
  The aim was to assess the incidence of prosthesis-patient mismatch (PPM) after mitral valve replacement (MVR) in patients receiving Biocor® porcine or mechanical valves, and to evaluate the effect of PPM on long-term survival.
  
  
  METHODS
  All patients undergoing MVR between 2009 and 2013 received either mechanical or bioprosthetic valves (Biocor® porcine). PPM was defined as severe when the indexed effective ori-fice area was < 0.9 cm2/m2, moderate between 0.9 cm2/m2 and 1.2 cm2/m2 or absent > 1.2 cm2/m2. The primary endpoint was all-cause long-term mortality.
  
  
  RESULTS
  Among a total of 136 MVR, PPM was severe in 27%, moderate in 44% and absent in 29% of patients. Implanted valves were 57% mechanical and 43% bioprosthetic. Only 3% of patients with mechanical valves had severe PPM vs. 59% with bioprostheses (p < 0.0001). Sixty-month survival with severe mismatch was 0.559 (SE 0.149) and with no mismatch 0.895 (SE 0.058) (p = 0.043). Survival of patients suffering from severe mismatch, or moderate mismatch with pulmonary hypertension (PH) was 0.749 (SE 0.101); while for patients with no mismatch or with moderate mismatch without PH, survival was 0.951 (SE 0.028) (p = 0.016).
  
  
  CONCLUSIONS
  About one-fourth of patients had severe PPM and almost all of them had received a bioprosthesis. Sixty-month survival was significantly lower in patients with severe mismatch, or moderate mismatch with PH. Specifically, when a bioprothesis is chosen and while further evidence on the impact of PPM on clinical outcomes appears, surgeons are recommended to follow a preoperative strategy to implant a mitral prosthesis of adequate size in order to prevent PPM.
authors.affiliation: Hospital de Clinicas, School of Medicine, Buenos Aires University, Buenos Aires, Argentina. raborracci@gmail.com.
authors.forename: Raul A
authors.initials: RA
authors.lastname: Borracci
authors.forename: Miguel
authors.initials: M
authors.lastname: Rubio
authors.forename: Maria L
authors.initials: ML
authors.lastname: Sestito
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Ingino
authors.forename: Carlos
authors.initials: C
authors.lastname: Barrero
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Rapallo
mesh_terms: D000368:Aged; D001118:Argentina / Q000453:epidemiology; D001705:Bioprosthesis / Q000009:adverse effects*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology / Q000209:etiology*; D015994:Incidence; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D011183:Postoperative Complications; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
keywords: bioprosthetic valves; long-term survival; mitral valve replacement; prosthesis-patient mismatch; pulmonary hypertension