title: Comparison of aortic valve gradient during exercise after aortic valve reconstruction.
abstract: OBJECTIVE
  Aortic valve preservation is a promising alternative to conventional composite replacement of aortic valve and ascending aorta. This approach may have a physiologic benefit compared with valve replacement similar to that seen in mitral valve reconstruction. We investigated aortic valve gradients at rest and during exercise in patients who had undergone valve-preserving aortic replacement and compared them with composite replacement of valve and aorta.
  
  
  METHODS
  Four groups were studied: nine patients underwent composite valve replacement (group A: valve diameter, 23 to 27 mm), eight patients underwent remodeling of the aortic root (group B), and another nine patients had reimplantation of the aortic valve (group C). Healthy volunteers were studied as a control group (group D). Using continuous-wave Doppler echocardiography, all patients were examined on a bicycle ergometer for aortic valve gradients (0 to 75 W).
  
  
  RESULTS
  There were no differences among the groups with respect to age, body surface, left ventricular end-diastolic diameter, fractional shortening, or left ventricular mass. Maximum resting gradients were significantly elevated in group A compared with groups B, C, and D (group A: 21.3 +/- 7.1 mm Hg; group B: 9.0 +/- 4.5 mm Hg; group C: 8.6 +/- 3.7 mm Hg; group D: 4.9 +/- 1.6 mm Hg; p < 0.05). At 75 W, group A exhibited significantly higher gradients than all other groups (group A: 31.3 +/- 7.5 mm Hg; group B: 13.9 +/- 6.6 mm Hg; group C: 12.8 +/- 3.5 mm Hg; group D: 9. 2 +/- 1.9 mm Hg; p < 0.05). There was no significant difference among the other groups. Both valve-preserving groups had only insignificantly higher gradients than the control group.
  
  
  CONCLUSIONS
  Our data strongly support the suggestion that preserving the aortic valve restores nearly normal hemodynamic function of the aortic valve. Long-term observations will have to prove the clinical relevance of restoring physiologic aortic valve hemodynamics.
authors.affiliation: Departments of Thoracic and Cardiovascular Surgery, University Hospitals, Hamburg, Germany. chtgrae@rz.uni-sb.de
authors.forename: T P
authors.initials: TP
authors.lastname: Graeter
authors.forename: M
authors.initials: M
authors.lastname: Kindermann
authors.forename: R
authors.initials: R
authors.lastname: Fries
authors.forename: F
authors.initials: F
authors.lastname: Langer
authors.forename: H J
authors.initials: HJ
authors.lastname: Schäfers
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001011:Aorta / Q000000981:diagnostic imaging / Q000601:surgery; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D001830:Body Surface Area; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D012146:Rest / Q000502:physiology; D018709:Statistics, Nonparametric; D016277:Ventricular Function, Left / Q000502:physiology