title: Indexing aortic valve area by body surface area increases the prevalence of severe aortic stenosis.
abstract: BACKGROUND
  To account for differences in body size in patients with aortic stenosis, aortic valve area (AVA) is divided by body surface area (BSA) to calculate indexed AVA (AVAindex). Cut-off values for severe stenosis are <1.0 cm2 for AVA and <0.6 cm2/m2 for AVAindex.
  
  
  OBJECTIVE
  To investigate the influence of indexation on the prevalence of severe aortic stenosis and on the predictive accuracy regarding clinical outcome.
  
  
  METHODS
  Echocardiographic and anthropometric data from a retrospective cohort of 2843 patients with aortic stenosis (jet velocity >2.5 m/s) and from 1525 patients prospectively followed in the simvastatin and ezetimibe in aortic stenosis (SEAS) trial were analysed.
  
  
  RESULTS
  The prevalence of severe stenosis increased with the AVAindex criterion compared to AVA from 71% to 80% in the retrospective cohort, and from 29% to 44% in SEAS (both p<0.001). Overall, the predictive accuracy for aortic valve events was virtually identical for AVA and AVAindex in the SEAS population (mean follow-up of 46 months; area under the receiver operating characteristic curve: 0.67 (95% CI 0.64 to 0.70) vs. 0.68 (CI 0.65 to 0.71) (NS). However, 213 patients additionally categorised as severe by AVAindex experienced significantly less valve related events than those fulfilling only the AVA criterion (p<0.001).
  
  
  CONCLUSIONS
  Indexing AVA by BSA (AVAindex) significantly increases the prevalence of patients with criteria for severe stenosis by including patients with a milder degree of the disease without improving the predictive accuracy for aortic valve related events.
authors: University Heart Centre Freiburg/Bad Krozingen, , Bad Krozingen, Germany.
authors: Nikolaus
authors: N
authors: Jander
authors: Christa
authors: C
authors: Gohlke-Bärwolf
authors: Edda
authors: E
authors: Bahlmann
authors: Eva
authors: E
authors: Gerdts
authors: Kurt
authors: K
authors: Boman
authors: John B
authors: JB
authors: Chambers
authors: Kenneth
authors: K
authors: Egstrup
authors: Christoph A
authors: CA
authors: Nienaber
authors: Terje R
authors: TR
authors: Pedersen
authors: Simon
authors: S
authors: Ray
authors: Anne B
authors: AB
authors: Rossebø
authors: Ronnie
authors: R
authors: Willenheimer
authors: Rolf-Peter
authors: RP
authors: Kienzle
authors: Kristian
authors: K
authors: Wachtell
authors: Franz-Josef
authors: FJ
authors: Neumann
authors: Jan
authors: J
authors: Minners
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013557:Switzerland / Q000453:epidemiology; D055815:Young Adult