title: Impact of complications on outcomes following aortic and mitral valve replacements in the United States.
abstract: OBJECTIVE
  Heart valve replacement surgeries account for 20% of all cardiac procedures. In-hospital mortality rates are approximately 6% for aortic valve replacements and 10% for mitral valve replacements. The objectives of the study are to provide nationally representative estimates of complications following aortic and mitral valve replacements and to quantify the impact of different types of complications on in-hospital outcomes.
  
  
  METHODS
  The Nationwide Inpatient Sample was analyzed for years 2000-2003. The effect of complications on in-hospital mortality, length of stay (LOS), and hospital charges were examined using bivariate and multivariable logistic and linear regression analyses. The confounding effects of age, sex, primary diagnosis, type of valve replacement, type of admission, comorbid conditions, and hospital characteristics were adjusted.
  
  
  RESULTS
  A total of 43,909 patients underwent aortic valve replacement as the primary procedure during the study period and 16,516 patients underwent mitral valve replacement. Complications occurred in 35.2% of those undergoing aortic valve replacements and in 36.4% of those undergoing mitral valve replacements. Almost half of these are cardiac complications and a quarter involve hemorrhage/hematoma/seroma. Complications were significantly associated with in-hospital mortality, LOS, and hospital charges even after adjusting for patient and hospital characteristics.
  
  
  CONCLUSIONS
  Complications are prevalent and exert a considerable influence on outcomes following aortic and mitral valve replacements. Quality initiatives should focus on minimizing complications and improving processes of care that would enable complications to be better resolved if they occur.
authors.affiliation: Department of Health Management and Policy, College of Public Health, The University of Iowa, E107 General Hospital, Iowa City, IA 52242-1008, USA.
authors.forename: V
authors.initials: V
authors.lastname: Allareddy
authors.forename: M M
authors.initials: MM
authors.lastname: Ward
authors.forename: J W
authors.initials: JW
authors.lastname: Ely
authors.forename: V
authors.initials: V
authors.lastname: Allareddy
authors.forename: J
authors.initials: J
authors.lastname: Levett
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D005260:Female; D006331:Heart Diseases / Q000191:economics / Q000209:etiology* / Q000401:mortality; D006349:Heart Valve Diseases / Q000191:economics / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000191:economics / Q000706:statistics & numerical data; D017721:Hospital Costs; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D011159:Population Surveillance; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology