title: Early surgical intervention or watchful waiting for the management of asymptomatic mitral regurgitation: a systematic review and meta-analysis.
abstract: BACKGROUND
  Discordance between studies drives continued debate regarding the best management of asymptomatic severe mitral regurgitation (MR). The aim of the present study was to conduct a systematic review and meta-analysis of management plans for asymptomatic severe MR, and compare the effectiveness of a strategy of early surgery to watchful waiting.
  
  
  METHODS
  A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Studies were excluded if they: (I) lacked a watchful waiting cohort; (II) included symptomatic patients; or (III) included etiologies other than degenerative mitral valve disease. The primary outcome of the study was all-cause mortality at 10 years. Secondary outcomes included operative mortality, repair rate, repeat mitral valve surgery, and development of new atrial fibrillation.
  
  
  RESULTS
  Five observational studies were eligible for review and three were included in the pooled analysis. In asymptomatic patients without class I triggers (symptoms or ventricular dysfunction), pooled analysis revealed a significant reduction in long-term mortality with an early surgery approach [hazard ratio (HR) =0.38; 95% confidence interval (CI): 0.21-0.71]. This survival benefit persisted in a sub-group analysis limited to patients without class II triggers (atrial fibrillation or pulmonary hypertension) [relative risk (RR) =0.85; 95% CI: 0.75-0.98]. Aggregate rates of operative mortality did not differ between treatment arms (0.7% vs. 0.7% for early surgery vs. watchful waiting). However, significantly higher repair rates were achieved in the early surgery cohorts (RR =1.10; 95% CI: 1.02-1.18).
  
  
  CONCLUSIONS
  Despite disagreement between individual studies, the present meta-analysis demonstrates that a strategy of early surgery may improve survival and increase the likelihood of mitral valve repair compared with watchful waiting. Early surgery may also benefit patients when instituted prior to the development of class II triggers.
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: Andrew B
authors: AB
authors: Goldstone
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: William L
authors: WL
authors: Patrick
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: Jeffrey E
authors: JE
authors: Cohen
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: Chiaka N
authors: CN
authors: Aribeana
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: Rita
authors: R
authors: Popat
authors: 1 Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, USA ; 2 Division of Cardiovascular Surgery, Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA ; 3 Department of Health Research and Policy, Stanford University School of Medicine, Stanford, USA.
authors: Y Joseph
authors: YJ
authors: Woo
keywords: Mitral regurgitation (MR); mitral valve prolapse; mitral valve repair