title: Grading Aortic Stenosis With Mean Gradient and Aortic Valve Area: A Comparison Between Preoperative Transthoracic and Precardiopulmonary Bypass Transesophageal Echocardiography.
abstract: OBJECTIVE
  The authors hypothesized that average precardiopulmonary bypass (pre-CPB) transesophageal echocardiographic (TEE) mean gradient (PGm) and aortic valve area (AVA) values would be significantly different from preoperative transthoracic (TTE) values in the same patients and that these changes would affect pre-CPB TEE grading of aortic stenosis (AS).
  
  
  METHODS
  Retrospective, observational design.
  
  
  METHODS
  Single university hospital.
  
  
  METHODS
  The study comprised 92 patients who underwent aortic valve replacement with or without coronary artery bypass grafting between 2000 and 2012 at Duke University Hospital and who had PGm and AVA values recorded in both pre-CPB TEE and preoperative TTE reporting databases.
  
  
  METHODS
  None.
  
  
  RESULTS
  PGm with pre-CPB TEE was lower by 6.6 mmHg (95% confidence interval, -4.0 to -9.3 mmHg; p<0.001), whereas AVA was higher by 0.10 cm(2) (95% confidence interval, 0.04 to 0.15 cm(2); p<0.001), compared with preoperative TTE values. When using PGm, pre-CPB TEE generated an AS severity 1 grade lower 39.1% of the time and revealed no difference 55.4% of the time compared to preoperative TTE. When using AVA by continuity, pre-CPB TEE generated an AS severity 1 grade lower 14.1% of the time and revealed no difference 81.5% of the time compared to preoperative TTE. When using either PGm or AVA, preoperative TTE exhibited moderate or severe AS for all study patients, whereas, pre-CPB TEE demonstrated mild AS in 5.4% (n = 92) of patients.
  
  
  CONCLUSIONS
  The authors confirmed their hypothesis that pre-CPB TEE generates different PGm and AVA values compared with preoperative TTE. These differences often underestimate AS severity. Hemodynamic standardizations or adjustments of pre-CPB TEE PGm and AVA values may be necessary in anesthetized patients before assigning an AS grade using these parameters.
authors: Department of Anesthesiology, Duke University. Electronic address: whiteneg@musc.edu.
authors: George
authors: G
authors: Whitener
authors: Department of Cardiology, Duke University Medical Center.
authors: Joseph
authors: J
authors: Sivak
authors: Duke University Social Science Research Institute, Duke University, Durham, NC.
authors: Igor
authors: I
authors: Akushevich
authors: Department of Cardiology, Duke University Medical Center.
authors: Zainab
authors: Z
authors: Samad
authors: Department of Anesthesiology, Duke University.
authors: Madhav
authors: M
authors: Swaminathan
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002315:Cardiopulmonary Bypass; D004452:Echocardiography / Q000379:methods / Q000706:statistics & numerical data*; D017548:Echocardiography, Transesophageal / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: aortic stenosis; aortic valve area; discordance; mean gradient; precardiopulmonary bypass (intraoperative) transesophageal echocardiography