I got this off the following database (ie not google): EBM Reviews -
Cochrane Central Register of Controlled Trials. Its the abstract to a
paper that may help. To get the full paper you will need access to
The Journal of heart valve disease. You could try a university
library.
"Database: EBM Reviews - Cochrane Central Register of Controlled Trials
Accession Number: CN-00489982
Author: Eichinger WB, Botzenhardt F, Guenzinger R, Bleiziffer S,
Keithahn A, Bauernschmitt R, Lange R
Institution: Department of Cardiovascular Surgery, German Heart Centre
Munich, Lazarettstr. 36, 80636 Munich, Germany. eichinger@dhm.mhn.de
Title: The effective orifice area/patient aortic annulus area ratio: a
better way to compare different bioprostheses? A prospective
randomized comparison of the Mosaic and Perimount bioprostheses in the
aortic position.
Source: The Journal of heart valve disease. 13(3):382-8; discussion
388-9, 2004 May.
Abstract: BACKGROUND AND AIM OF THE STUDY: The aim of this
prospective, randomized study was to compare the hemodynamic
performance of the Medtronic Mosaic and Edwards Perimount
bioprostheses in the aortic position, and to evaluate
prosthesis-specific differences in valve sizing and valve-size
labeling. METHODS: Between August 2000 and September 2002, 139
patients underwent isolated aortic valve replacement (AVR) with the
Mosaic (n = 67) or Perimount (n = 72) bioprosthesis. Intraoperatively,
the internal aortic annulus diameter was measured by insertion of a
gauge (Hegar dilator), while prosthesis size was determined by using
the original sizers. Transthoracic echocardiography was performed to
determine hemodynamic and dimensional data. As the aim of AVR is to
achieve a maximal effective orifice area (EOA) within a given aortic
annulus, the ratio of EOA to patient aortic annulus area was
calculated, the latter being based on annulus diameter measured
intraoperatively. RESULTS: Operative mortality was 2.2% (Mosaic 3.0%;
Perimount 1.4%; p = NS). Upsizing (using a prosthesis larger in
labeled valve size than the patient's measured internal aortic annulus
diameter) was possible in 28.4% of Mosaic patients and 8.3% of
Perimount patients. The postoperative mean systolic pressure gradient
ranged from 10.5 to 22.2 mmHg in the Mosaic group, and from 9.4 to
12.6 mmHg in the Perimount group; it was significantly lower for 21
and 23 Perimount valves than for 21 and 23 Mosaic valves. The EOA
ranged from 0.78 to 2.37 cm2 in Mosaic patients, and from 0.95 to 2.12
cm2 in Perimount patients. When indexing EOA by calculating the ratio
of EOA to patient aortic annulus area to adjust for variables such as
patient anatomy and valve dimensions, there was no significant
difference between the two bioprostheses. CONCLUSION: Comparisons of
absolute EOA values grouped by the manufacturers' valve sizes are
misleading because of specific differences in geometric dimensions.
The EOA:patient aortic annulus area ratio provides a new hemodynamic
index which may facilitate objective comparisons between different
valve types." |
