Hemodynamic Comparison of Tissue Aortic Valves
Hemodynamic Comparison of Tissue Aortic Valves
The purpose of this study is to:

 1. Assess for hemodynamic differences at rest and with exercise between three clinically
 available tissue aortic valves.

 2. Assess for differences in left ventricular (LV) reverse remodeling (recovery of LV
 hypertrophy, and changes in LV systolic and diastolic function) after aortic valve
 replacement for severe aortic stenosis (AS) between three clinically available aortic
 valve bioprosthesis.
Various aortic valve prostheses have unique hemodynamic characteristics, and there is
 on-going interest in defining those hemodynamic characteristics in the interest of avoiding
 residual LV outflow obstruction and prosthesis-patient mismatch (residual LV outflow
 obstruction despite a normally functioning prosthesis ) after aortic valve replacement.
 Attempts to compare hemodynamics between prostheses have been limited by different sizing
 systems used by various manufacturers (precluding meaningful comparison of valves by valve
 size) and biological variability of in vivo gradients and effective orifice area for any
 valve (making potentially small differences in hemodynamics difficult to detect). Assessment
 of hemodynamics during increased cardiac output associated with exercise testing has been
 used to better define potentially subtle differences in hemodynamics between valve
 prostheses. In addition, assessment for change in LV geometry (notably including LV
 hypertrophy) after aortic valve replacement has been used as a surrogate marker of aortic
 prosthesis hemodynamics.
Inclusion Criteria:

 -  Age ≥ 18 years.

 -  Severe aortic stenosis (AS) based on overall clinical impression, with or without
 aortic valve mean gradient ≥ 40 mm Hg, EOA < 1.0 cm2, or EOA index < 0.6 cm2/m2.

 -  Scheduled for clinically indicated elective aortic valve replacement for a primary
 diagnosis of severe AS.

 -  Less than moderate aortic regurgitation on preoperative testing.

 -  Isolated aortic valve replacement; or aortic valve replacement with concomitant
 coronary artery bypass grafting, ascending aorta repair, or mitral and/or tricuspid
 annuloplasty for functional mitral regurgitation / tricuspid regurgitation.

 -  Left ventricular ejection fraction ≥ 40% on preoperative testing.

 -  Physically able and willing to pedal a recumbent bicycle.

 -  Patient and surgeon agree that the patient will undergo valve replacement with a
 bioprosthesis.

 -  Patient and surgeon agree that the use of one specific bioprosthesis manufacturer /
 model is not indicated based on clinical criteria.

 -  Willing to undergo randomization to have implanted one of three bioprosthesis at the
 time of aortic valve replacement.

 -  Willing and able to undergo preoperative echocardiography/Doppler for purposes of the
 research study.

 -  Willing and able to undergo post-operative exercise stress echocardiography/Doppler 5
 to 7 months after valve replacement for purposes of the research protocol.

 Exclusion Criteria:

 -  Age < 18 years.

 -  AS felt by overall clinical impression to be less than severe.

 -  Aortic valve replacement is urgent or emergent.

 -  Moderate of more aortic regurgitation on preoperative testing.

 -  Concomitant mitral or tricuspid valve replacement.

 -  Left ventricular ejection fraction < 40% on preoperative testing.

 -  Physically unable or unwilling to pedal a recumbent bicycle.

 -  Planned aortic valve replacement with a mechanical prosthesis.

 -  Operating surgeon believes that any one of the three protocol bioprosthetic devices is
 contraindicated based on clinical criteria.

 -  Not willing to undergo randomization to have implanted one of three bioprosthesis.

 -  Unwilling or unable to undergo preoperative echocardiography/Doppler for purposes of
 the research protocol.

 -  Unwilling or unable to undergo post-operative exercise stress echocardiography/Doppler
 5 to 7 months after valve replacement for purposes of the research protocol.