title: Assessment of aortic stenosis by three-dimensional echocardiography: an accurate and novel approach.
abstract: BACKGROUND
  Accurate assessment of aortic valve area (AVA) is important for clinical decision-making in patients with aortic valve stenosis (AS). The role of three-dimensional echocardiography (3D) in the quantitative assessment of AS has not been evaluated so far.
  
  
  OBJECTIVE
  To evaluate the reproducibility and accuracy of real-time three-dimensional echocardiography (RT3D) and 3D-guided two-dimensional planimetry (3D/2D) for assessment of AS, and compare these results with those of standard echocardiography and cardiac catheterisation (Cath).
  
  
  METHODS
  AVA was estimated by transthoracic echo-Doppler (TTE) and by direct planimetry using transoesophageal echocardiography (TEE) as well as RT3D and 3D/2D. 15 patients underwent assessment of AS by Cath.
  
  
  RESULTS
  33 patients with AS were studied (20 men, mean (SD) age 70 (14) years). Bland-Altman analysis showed good agreement and small absolute differences in AVA between all planimetric methods (RT3D vs 3D/2D: -0.01 (0.15) cm(2); 3D/2D vs TEE: 0.05 (0.22) cm(2); RT3D vs TEE: 0.06 (0.26) cm(2)). The agreement between AVA assessment by 2D-TTE and planimetry was -0.01 (0.20) cm(2) for 3D/2D; 0.00 (0.15) cm(2) for RT3D; and -0.05 (0.30) cm(2) for TEE. Correlation coefficient r for AVA assessment between each of 3D/2D, RT3D, TEE planimetry and Cath was 0.81, 0.86 and 0.71, respectively. The intraobserver variability was similar for all methods, but interobserver variability was better for 3D techniques than for TEE (p<0.05).
  
  
  CONCLUSIONS
  The 3D echo methods for planimetry of the AVA showed good agreement with the standard TEE technique and flow-derived methods. Compared with AV planimetry by TEE, both 3D methods were at least as good as TEE and had better reproducibility. 3D aortic valve planimetry is a novel non-invasive technique, which provides an accurate and reliable quantitative assessment of AS.
authors.affiliation: Department of Cardiology and Cardiothoracic Surgery, Cedars-Sinai Medical Center, Los Angeles, California, USA.
authors.forename: Sorel
authors.initials: S
authors.lastname: Goland
authors.forename: Alfredo
authors.initials: A
authors.lastname: Trento
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Iida
authors.forename: Lawrence S C
authors.initials: LS
authors.lastname: Czer
authors.forename: Michele
authors.initials: M
authors.lastname: De Robertis
authors.forename: Tasneem Z
authors.initials: TZ
authors.lastname: Naqvi
authors.forename: Kirsten
authors.initials: K
authors.lastname: Tolstrup
authors.forename: Takashi
authors.initials: T
authors.lastname: Akima
authors.forename: Huai
authors.initials: H
authors.lastname: Luo
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Siegel
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging*; D006328:Cardiac Catheterization / Q000592:standards; D019560:Echocardiography, Three-Dimensional / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity