title: Should patients with severe degenerative mitral regurgitation delay surgery until symptoms develop?
abstract: BACKGROUND
  The American College of Cardiology/American Heart Association practice guidelines recommending surgery for asymptomatic patients with severe mitral regurgitation caused by degenerative disease remain controversial. This study examined whether delaying surgery until symptoms occur causes adverse cardiac changes and jeopardizes outcome.
  
  
  METHODS
  From January 1985 to January 2008, 4,586 patients had primary isolated mitral valve surgery for degenerative mitral regurgitation; 4,253 (93%) underwent repair. Preoperatively, 30% were in New York Heart Association (NYHA) class I (asymptomatic), 56% in class II, 13% in class III, and 2% in class IV. Multivariable analysis and propensity matching were used to assess association of symptoms (NYHA class) with cardiac structure and function and postoperative outcomes.
  
  
  RESULTS
  Increasing NYHA class was associated with progressive reduction in left ventricular function, left atrial enlargement, and development of atrial fibrillation and tricuspid regurgitation. These findings were evident even in class II patients (mild symptoms). Repair was accomplished in 96% of asymptomatic patients, and in progressively fewer as NYHA class increased (93%, 86%, and 85% in classes II to IV, respectively; p < 0.0001). Hospital mortality was 0.37%, but was particularly high in class IV (0.29%, 0.20%, 0.67%, and 5.1% for classes I to IV, respectively; p = 0.004). Although long-term survival progressively diminished with increasing NHYA class, these differences were largely related to differences in left ventricular function and increased comorbidity.
  
  
  CONCLUSIONS
  In patients with severe degenerative mitral regurgitation, the development of even mild symptoms by the time of surgical referral is associated with deleterious changes in cardiac structure and function. Therefore, particularly because successful repair is highly likely, early surgery is justified in asymptomatic patients with degenerative disease and severe mitral regurgitation.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, Cleveland, OH 44195, USA. gillinom@ccf.org
authors.forename: A Marc
authors.initials: AM
authors.lastname: Gillinov
authors.forename: Tomislav
authors.initials: T
authors.lastname: Mihaljevic
authors.forename: Eugene H
authors.initials: EH
authors.lastname: Blackstone
authors.forename: Kristopher
authors.initials: K
authors.lastname: George
authors.forename: Lars G
authors.initials: LG
authors.lastname: Svensson
authors.forename: Edward R
authors.initials: ER
authors.lastname: Nowicki
authors.forename: Joseph F
authors.initials: JF
authors.lastname: Sabik
authors.forename: Penny L
authors.initials: PL
authors.lastname: Houghtaling
authors.forename: Brian
authors.initials: B
authors.lastname: Griffin
mesh_terms: D005260:Female; D006331:Heart Diseases / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D011446:Prospective Studies; D012720:Severity of Illness Index; D013997:Time Factors