title: Surgical Treatment of Posterior Mitral Valve Prolapse: Towards 100% Repair.
abstract: BACKGROUND
  The study aim was to evaluate the immediate and long-term results of surgical treatment of isolated posterior mitral valve leaflet prolapse (PLP), focusing on survival and freedom from recurrent mitral regurgitation (MR).
  
  
  METHODS
  Between January 1998 and December 2012, a total of 492 consecutive patients (375 males, 117 females; mean age 61.8 ± 12.1 years; range: 13-86 years) with isolated PLP [304 (61.8%) with myxomatous degeneration; 188 (38.2%) with fibroelastic deficiency] were treated at the authors' institution. Of these patients, 202 (41.1%) were in NYHA class III-IV, and atrial fibrillation was present in 104 (21.1%). Mitral valve repair was achieved in 484 patients (98.4%), resection was performed in 419 (85.2%), and prosthetic ring annuloplasty was used in 436 (88.6%). Concomitant procedures were performed in 153 patients (31.1%), including tricuspid valve repair in 50 (10.2%), aortic valve surgery in 34 (6.9%), and coronary artery bypass grafting (CABG) in 64 (13%).
  
  
  RESULTS
  The hospital mortality rate was 0.2%, and the mean follow up was 7.1 ± 3.9 years. There were 71 late deaths (14.4%), and overall survival at five, 10 and 15 years was 91.7 ± 1.3%, 82.1 ± 2.3% and 64.7 ± 6.1%, respectively. There was no significant difference in long-term survival compared with the age- and gender-matched general population (p = 0.146). Multivariate Cox-proportional hazard analysis showed older age (HR 1.03 per annum), left ventricular dysfunction (HR 2.44), atrial fibrillation (HR 1.96), left ventricular end-diastolic dimension (HR 1.05 per mm) and non-use of prosthetic ring (HR 3.03) as significant predictors of late mortality. Recurrence of moderate or severe MR occurred in 31 patients, six of whom underwent mitral valve reoperation. Predictors of late recurrence of MR were fibroelastic deficiency (HR 2.38), mitral calcification (HR 5.26), posterior leaflet plication (HR 3.58), absence of complete ring annuloplasty (HR 3.84) and systolic pulmonary artery pressure at discharge (HR 1.10 per mmHg). Freedom from mitral valve reoperation at 15 years was 97.4 ± 1.1% CONCLUSIONS: Mitral valve repair in isolated PLP can be achieved in virtually all cases with a very low operative risk and a high durability of repair. Atrial fibrillation or large left ventricles are associated with a poor prognosis. Failure to use a complete ring annuloplasty carries a risk not only for the return of MR but also for survival.
authors.affiliation: Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Portugal.
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Correia
authors.affiliation: Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Portugal.
authors.forename: Gonçalo F
authors.initials: GF
authors.lastname: Coutinho
authors.affiliation: Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Branco
authors.affiliation: Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Garcia
authors.affiliation: Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Portugal.
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Antunes