Data provided by company:

• The CarboMedics Top Hat supraannular aortic valve provides an orifice-to-annulus ratio of 1:1 in most patients, and enhances patient outcomes ⁴
• Top Hat prosthesis implanted was significantly larger (by a mean of 3.29 mm) than the valve size indicated using an intraannular valve size ⁴
• The larger orifice-to-annulus ratio of the Top Hat valve improved hemodynamic parameters assessed by echocardiography up to 4 years postoperatively, with a lower transvalvular gradient, hence decreased left ventricular workload ⁴

Comments Surgery:

• Bileaflet, supra-annular design without valve components in the annulus (CAVE: coronary ostia), allows for one or two size increase over intra-annular valves, no ventricular protrusions, rotatability in-situ 

Comments Echocardiography:

• No EOAi calculator available

References:

1. Rosenhek et al. Normal Values for Doppler Echocardiographic Assessment of Heart ValveProstheses. Journal of the American Society of Echocardiography, November 2003
2. Copyright by Sorin Group
3. /*  Chambers J. et al., Echocardiographic description of the CarboMedics bileaflet prosthetic heart valve, J Am Coll Cardiol., Februar 1993:21(2):398-405
4. /** Aagaard J. et al., Midterm evaluation of hemodynamics of the Top Hat supraannular aortic valve, J Asian Cardiovasc Thorac Ann, Februar 2010;18(1):54-8