title: Analysis of mitral valve replacement outcomes is enhanced by meaningful clinical use of electronic health records.
abstract: OBJECTIVE
  Cardiac surgical mortality has improved during the last decade despite the aging of the population. An integrated US health plan developed a heart valve registry to track outcomes and complications of heart valve operations. This database was used for longitudinal evaluation of mitral valve (MV) outcomes from 1999 to 2008 at four affiliated hospitals.
  
  
  METHODS
  We identified 3130 patients in the Apollo database who underwent 3180 initial MV procedures. Internal administrative and Social Security Administration databases were merged to determine survival rates. Electronic health records were searched to ascertain demographics, comorbidities, and postoperative complications. Cox regression was used to evaluate mean survival and identify risk factors.
  
  
  RESULTS
  The procedures included 1160 mechanical valve replacements, 1159 tissue valve replacements, and 861 annuloplasties. The mean age of patients undergoing these procedures was 58 ± 11 years, 69 ± 12 years, and 62 ± 12 years, respectively. Mean survival was 8.9 ± 0.1 years for mechanical valve replacement, 7.0 ± 0.1 years for tissue valve replacement, and 7.7 ± 0.1 years for annuloplasty. Early in the study, there was a preference for implanting mechanical MVs. Beginning in 2003, more patients received tissue valve replacements rather than mechanical valves. Over time, there was an increasing trend of annuloplasty. Cox regression analysis identified the following risk factors for increased ten-year mortality: tissue valve implantation; advanced age; female sex; nonelective, nonisolated procedure; diabetes; postoperative use of banked blood products; previous cardiovascular intervention; dialysis; and longer perfusion time. Hospital location, reoperation, preoperative anticoagulation, and cardiogenic shock were not statistically significant risk factors.
  
  
  CONCLUSIONS
  When controlling for other risk factors, we observed a lower long-term survival rate for tissue valve replacement compared with mechanical valve replacement. Integrating electronic health records with existing electronic databases provided near-real-time analysis of longitudinal cardiac surgical outcomes.
authors.affiliation: Cardiothoracic Surgeon at the Honolulu Medical Center in HI, USA. john.c.chen@kp.org
authors.forename: John C
authors.initials: JC
authors.lastname: Chen
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfeffer
authors.forename: Shelley
authors.initials: S
authors.lastname: Johnstone
authors.forename: Yuexin
authors.initials: Y
authors.lastname: Chen
authors.forename: Mary-Lou
authors.initials: ML
authors.lastname: Kiley
authors.forename: Richard
authors.initials: R
authors.lastname: Richter
authors.forename: Hon
authors.initials: H
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D057286:Electronic Health Records; D005260:Female; D006350:Heart Valve Prosthesis / Q000706:statistics & numerical data; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000401:mortality*; D006801:Humans; D008297:Male; D062527:Meaningful Use; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D012042:Registries; D012044:Regression Analysis; D012307:Risk Factors; D015996:Survival Rate; D014481:United States / Q000453:epidemiology