title: Objective quantification of aortic valvular structures by cardiac computed tomography angiography in patients considered for transcatheter aortic valve implantation.
abstract: OBJECTIVE
  To test the ability of a model-based segmentation of the aortic root for consistent assessment of aortic valve structures in patients considered for transcatheter aortic valve implantation (TAVI) who underwent 256-slice cardiac computed tomography (CT).
  
  
  METHODS
  Consecutive patients (n = 49) with symptomatic severe aortic stenosis considered for TAVI and patients without aortic stenosis (n = 17) underwent cardiac CT. Images were evaluated by two independent observers who measured the diameter of the aortic annulus and its distance to both coronary ostia (1) manually and (2) software-assisted. All acquired measures were compared with each other and to (3) fully automatic quantification.
  
  
  RESULTS
  High correlations were observed for 3D measures of the aortic annulus conducted on multiple oblique planes (r = 0.87 and 0.84 between observers and model-based measures, and r = 0.81 between observers). Reproducibility was further improved by software-assisted versus manual assessment for all the acquired variables (r = 0.98 versus 0.81 for annulus diameter, r = 0.94 versus 0.85 for distance to the left coronary ostium, P < 0.01 for both). Thus, using software-assisted measurements very low limits of agreement were observed for the annulus diameter (95%CI of -1.2 to 0.6 mm) and within very low time-spent (0.6 ± 0.1 min for software-assisted versus 1.6 ± 0.3 min per patient for manual assessment, P < 0.001). Assessment of the aortic annulus using the 3D model-based instead of manual 2D-coronal measurements would have modified the implantation strategy in 12 of 49 patients (25%) with aortic stenosis. Four of 12 patients with potentially modified implantation strategy yielded postprocedural moderate paravalvular regurgitation, which may have been avoided by implantation of a larger prosthesis, as suggested by automatic 3D measures.
  
  
  CONCLUSIONS
  Our study highlights the usefulness of software-assisted preprocedural assessment of the aortic annulus in patients considered for TAVI.
authors.affiliation: University of Heidelberg, Department of Cardiology, Heidelberg, Germany. grigorios.korosoglou@med.uni-heidelberg.de
authors.forename: Grigorios
authors.initials: G
authors.lastname: Korosoglou
authors.forename: Gitsios
authors.initials: G
authors.lastname: Gitsioudis
authors.forename: Irina
authors.initials: I
authors.lastname: Waechter-Stehle
authors.forename: Juergen
authors.initials: J
authors.lastname: Weese
authors.forename: Ulrike
authors.initials: U
authors.lastname: Krumsdorf
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chorianopoulos
authors.forename: Waldemar
authors.initials: W
authors.lastname: Hosch
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Hugo A
authors.initials: HA
authors.lastname: Katus
authors.forename: Raffi
authors.initials: R
authors.lastname: Bekeredjian
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology; D001024:Aortic Valve Stenosis; D006328:Cardiac Catheterization / Q000379:methods*; D016022:Case-Control Studies; D005069:Evaluation Studies as Topic; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011446:Prospective Studies; D011857:Radiographic Image Interpretation, Computer-Assisted; D018570:Risk Assessment; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome