title: The MitraClip and survival in patients with mitral regurgitation at high risk for surgery: A propensity-matched comparison.
abstract: BACKGROUND
  We compared 30-day and 1-year survival among high-risk mitral regurgitation (MR) patients treated with the MitraClip (Abbott Vascular, Abbott Park, IL) with matched non-surgically treated patients from the Duke Echocardiography Laboratory Database (DELD).
  
  
  RESULTS
  High-risk patients with 3+/4+ MR managed non-surgically between years 2000 and 2010 in the longitudinal DELD were matched to high-risk MitraClip patients. Patient matching was performed using the method of nearest available Mahalanobis distance metric within calipers defined by the propensity score. Kaplan-Meier estimates and stratified Cox proportional hazards models were used to compare survival at 30 days and 1 year. Among 953 high-risk DELD patients available for matching, 30-day and 1-year mortality were 6.5% and 26.2%. Close matches were obtained for 239 of the 351 MitraClip patients. The 30-day mortality in MitraClip patients was lower (4.2%) when compared with matched DELD patients (7.2%). The 1-year relative risk of mortality of the MitraClip compared with non-surgical treatment was 0.64 (95% CI 0.45-0.91; log-rank P = .013). These results in favor of the MitraClip remained significant upon further adjustment for baseline differences between groups (P = .043).
  
  
  CONCLUSIONS
  This matched comparison of severe MR patients at high surgical risk supports the safety of the MitraClip relative to medical therapy at 30 days and a survival benefit at 1 year.
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC; Division of Cardiology, Duke University Medical Center, Durham, NC. Electronic address: eric.velazquez@duke.edu.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Velazquez
authors.affiliation: Division of Cardiology, Duke University Medical Center, Durham, NC.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Samad
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC.
authors.forename: Hussein R
authors.initials: HR
authors.lastname: Al-Khalidi
authors.affiliation: Abbott Vascular, Abbott Park, IL.
authors.forename: Chithra
authors.initials: C
authors.lastname: Sangli
authors.affiliation: Baylor Heart and Vascular Institute, Dallas, TX.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Grayburn
authors.affiliation: Harvard Clinical Research Institute, Boston, MA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Massaro
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC.
authors.forename: Susanna R
authors.initials: SR
authors.lastname: Stevens
authors.affiliation: NorthShore University HealthSystem Evanston Hospital, Evanston, IL.
authors.forename: Ted E
authors.initials: TE
authors.lastname: Feldman
authors.affiliation: Duke Clinical Research Institute, Duke University Medical Center, Durham, NC; Division of Cardiology, Duke University Medical Center, Durham, NC.
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Krucoff
mesh_terms: D000368:Aged; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology