title: The effect of aortic area measurement site on the energy loss coefficient: a comparison between echocardiography and cardiac computed tomography angiography in patients with aortic stenosis.
abstract: OBJECTIVE
  The energy loss coefficient (ELCo) has been suggested as a more accurate indicator of aortic stenosis (AS) severity as compared to transthoracic echocardiography (TTE) aortic valve area (AVA). There are little data regarding the optimal location for aortic area (Aa) measurement needed for ELCo calculation and the agreement of ELCo with direct anatomical AVA measurement. The aim of this study was to determine the optimal site of Aa measurement for calculation of the ELCo, using cardiac computed tomography angiography (CCTA) AVA planimetry as the reference standard.
  
  
  METHODS
  We analyzed 69 patients with AS who underwent both CCTA and TTE. ELCo and CCTA planimetry AVA were compared using multiple sites for CCTA Aa measurement (sinus, sinotubular junction, or ascending aorta).
  
  
  RESULTS
  CCTA AVA was 0.96±0.46 cm2. ELCo was 0.95±0.43 cm2using sinotubular junction Aa, 0.92±0.41 cm2using sinus Aa, and 0.91±0.4 cm2using the ascending aorta (P=.84, P=.13, and P=.08 compared to CCTA AVA). There was good agreement between CCTA AVA and ELCo using all Aa locations (0.89-0.90). On subgroup analysis of 16 patients most likely to be affected by pressure recovery (aortic diameter<3 cm and AVA ≥1 cm2), ELCo using the sinotubular junction Aa showed the best agreement with CCTA AVA as compared to the other Aa locations (0.84 vs 0.75-0.77).
  
  
  CONCLUSIONS
  ELCo using Aa measurement at the sinotubular junction showed the best agreement with CCTA AVA. We therefore recommend using the sinotubular junction Aa for ELCo calculation.
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors: Dotan
authors: D
authors: Yaari
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Ronen
authors: R
authors: Rubinshtein
authors: Department of Radiology, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Robert
authors: R
authors: Sachner
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Radiology, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Tamar
authors: T
authors: Gaspar
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Salim
authors: S
authors: Adawi
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Ronen
authors: R
authors: Jaffe
authors: Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Ihab
authors: I
authors: Asmer
authors: Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Majdi
authors: M
authors: Ganaeem
authors: Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.|Department of Cardiovascular Medicine, Lady Davis Carmel Medical Center, Haifa, Israel.
authors: Avinoam
authors: A
authors: Shiran
mesh_terms: D000368:Aged; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001021:Aortic Valve / Q000000981:diagnostic imaging*; D001024:Aortic Valve Stenosis / Q000175:diagnosis* / Q000503:physiopathology; D000072226:Computed Tomography Angiography / Q000379:methods*; D018619:Echocardiography, Doppler, Pulsed / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D012039:Regional Blood Flow / Q000502:physiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: aortic stenosis; cardiac computed tomography angiography; energy loss coefficient; energy loss index; transthoracic echocardiography