title: Incremental value of three-dimensional echocardiography in the evaluation of left ventricular size in mitral regurgitation: a follow-up study after mitral valve surgery.
abstract: BACKGROUND
  Increased left ventricular (LV) dimensions are an indication for surgery in patients with asymptomatic mitral regurgitation, but M-mode or two-dimensional measurements have known limitations. The aim of this study was to determine the value of three-dimensional echocardiography in predicting postoperative outcomes after mitral surgery.
  
  
  METHODS
  Sixty-seven patients with severe asymptomatic or minimally symptomatic mitral regurgitation (69% men; mean age, 62 ± 13 years) who underwent mitral valve surgery from January 2010 to December 2011 were studied. In addition to standard echocardiography, baseline three-dimensional echocardiography was performed for accurate quantification of LV size. Patients were followed over a median time of 1 month (interquartile range, 0-8 months) for postoperative development of atrial fibrillation or LV dysfunction. A multivariate regression analysis was performed to identify associations with events.
  
  
  RESULTS
  Postoperative LV dysfunction developed in 15 patients (22%), and 21 patients (31%) had postoperative atrial fibrillation. There was no association between two-dimensional end-systolic volume index and outcomes (hazard ratio, 1.02; P = .18). Postoperative atrial fibrillation or LV dysfunction was associated with baseline three-dimensional LV end-systolic volume index (hazard ratio, 1.06; 95% confidence interval, 1.04-1.16), independent of age and presence of coronary artery disease. LVESVi ≥ 40 mL/m(2) was the best cutoff value to predict postoperative events (sensitivity, 80%; specificity, 85%). After adding LVESVi to a model containing clinical and echocardiographic parameters, net reclassification improvement was 0.27 (95% confidence interval, 0.25-0.29; P = .024).
  
  
  CONCLUSIONS
  LVESVi from three-dimensional echocardiography is an independent predictor of postoperative outcomes in patients with severe mitral regurgitation that is incremental to other clinical and echocardiographic variables.
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
authors.forename: Teerapat
authors.initials: T
authors.lastname: Yingchoncharoen
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio. Electronic address: tom.marwick@utas.edu.au.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Negishi
authors.affiliation: University of Queensland, Brisbane, Australia.
authors.forename: Tony
authors.initials: T
authors.lastname: Stanton
authors.affiliation: Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio; Menzies Research Institute Tasmania, Hobart, Australia. Electronic address: tom.marwick@utas.edu.au.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D000368:Aged; D019560:Echocardiography, Three-Dimensional; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery*; D015999:Multivariate Analysis; D009929:Organ Size; D012372:ROC Curve; D016896:Treatment Outcome
keywords: LV dimensions; LV volume; Mitral regurgitation; Three-dimensional echocardiography; Two-dimensional echocardiography