title: Role of transvalvular gradient in outcome from valve replacement for aortic stenosis.
abstract: BACKGROUND
  Despite limitations the transvalvular gradient (TVG) still is commonly used in aortic stenosis when patients are referred for aortic valve replacement. We wished to ascertain if it had a role in predicting outcome from valve replacement rather than as an indicator of severity, specifically investigating if the TVG affected renal dysfunction, hospital stay, and medium-term survival after valve replacement.
  
  
  METHODS
  Six hundred and twenty-three consecutive patients who had aortic valve replacement were identified and 211 of these patients were isolated as first time replacement for aortic stenosis that formed the final study group, and were followed up for up to 48 months. Variables significant (p < 0.05) on univariate analysis were included in the logistic regression multivariate analysis (renal dysfunction, prolonged hospital stay) or Cox proportional hazard regression model (medium-term mortality).
  
  
  RESULTS
  A significant association was present between TVG and age (p = 0.001). Multivariate analysis demonstrated angina greater than or equal to grade 3 Canadian Cardiovascular Society (CCS 3; p = 0.014) and having nonelective surgery (p < 0.001) to be independent predictors of renal dysfunction. Angina greater than or equal to CCS 3 (p = 0.013) was the only independent predictor of prolonged hospital stay. Independent predictors of medium-term mortality on multivariate analysis were age (p = 0.043) and having a size 19 valve prosthesis (p = 0.015).
  
  
  CONCLUSIONS
  The TVG is inadequate as an independent predictor of the degree of aortic stenosis and outcome from aortic valve replacement in aortic stenosis. In contrast, the TVG may be a useful screening tool for detecting aortic stenosis in targeted elderly populations.
authors.affiliation: Department of Cardiothoracic Surgery, St. Bartholomew Hospital, London, United Kingdom. a.weerasinghe@ic.ac.uk
authors.forename: Arjuna
authors.initials: A
authors.lastname: Weerasinghe
authors.forename: Merangani
authors.initials: M
authors.lastname: Yusuf
authors.forename: Thanos
authors.initials: T
authors.lastname: Athanasiou
authors.forename: Alan
authors.initials: A
authors.lastname: Wood
authors.forename: Patrick
authors.initials: P
authors.lastname: Magee
authors.forename: Rakesh
authors.initials: R
authors.lastname: Uppal
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000503:physiopathology* / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000503:physiopathology* / Q000601:surgery*; D001783:Blood Flow Velocity; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D016896:Treatment Outcome