title: Cyclic changes in area- and perimeter-derived effective dimensions of the aortic annulus measured with multislice computed tomography and comparison with metric intraoperative sizing.
abstract: OBJECTIVE
  Multislice computed tomography (MSCT) is recommended for annular sizing prior to transcatheter aortic valve implantation (TAVI), but it remains unclear whether systolic or diastolic reconstructions should be used and whether the effective annular diameter should be derived by area or perimeter. In this study these different approaches were compared with intraoperative sizing.
  
  
  METHODS
  In 52 patients who were evaluated but deemed unsuitable for TAVI, the annulus was measured during conventional surgery using metric sizers (AnnOp) and compared with MSCT measurements (cross-sectional diameter derived by area [AnnAsys, AnnAdia; AnnAmean = (AnnAsys + AnnAdia)/2] and perimeter (AnnPsys, AnnPdia) in systole and diastole). Furthermore, TAVI was simulated based on AnnOp and the impact of the various MSCT approaches on sizing strategy was determined.
  
  
  RESULTS
  The best agreement with AnnOp [mean difference (limits of agreement)] was shown for AnnAmean [0.03 mm (-1.9 to 1.96)], whereas the strongest deviation was noted for AnnPsys [-1.08 mm (-3.01 to 0.86)]. Mean differences between systole and diastole were significant but small: 0.82 mm (3.5 %) for area- and 0.81 mm (3.3 %) for perimeter-derived measurements. Simulation of TAVI revealed the least change of strategy for AnnAmean (76.9 %) as compared with AnnPsys (53.8 %); between AnnAsys and AnnAdia sizing would have been deviant in 17.3 % due to relatively large intraindividual cyclic differences.
  
  
  CONCLUSIONS
  AnnAmean demonstrated the best agreement with AnnOp, whereas perimeter-derived measurements were somewhat overestimated. Despite a negligible average difference between systolic and diastolic annular values, in a subset of patients the intraindividual cyclic variability was relatively large and potentially of clinical impact.
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany. w.kim@kerckhoff-klinik.de.|Department of Cardiac Surgery, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany. w.kim@kerckhoff-klinik.de.
authors.forename: Won-Keun
authors.initials: WK
authors.lastname: Kim
authors.affiliation: Department of Cardiac Surgery, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Meyer
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Helge
authors.initials: H
authors.lastname: Möllmann
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rolf
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Möllmann
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Blumenstein
authors.affiliation: Department of Cardiac Surgery, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Van Linden
authors.affiliation: Department of Cardiology, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.|Department of Cardiology, Justus-Liebig University of Giessen, Giessen, Germany.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Hamm
authors.affiliation: Department of Cardiac Surgery, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walther
authors.affiliation: Department of Cardiac Surgery, Kerckhoff Heart and Lung Center, Benekestrasse 2-8, 61231, Bad Nauheim, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Kempfert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D003198:Computer Simulation; D003971:Diastole; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D013599:Systole
keywords: Annulus; Aortic stenosis; MSCT; TAVI