Abstract 6107: Evaluation of the Hemodynamic Performance of Aortic Bioprostheses by Multidetector Computed Tomography. A Feasibilty and Reproducibility Study
The effective orifice area (EOA) is a key parameter in the evaluation of patients after bioprosthetic aortic valve replacement (AVR). Unfortunately, in patients with poor echo windows, this parameter is difficult to obtain using conventional transthoracic echocardiography (TTE). Recently, Multidetector Computed Tomography (MDCT) was shown to accurately assess aortic valve area in native aortic stenosis. In this study, we tested the hypothesis that MDCT could also be useful in the evaluation of pts with aortic bioprostheses. 48 patients (mean age 75 ± 8 years; 21 males) with an aortic bioprosthesis (44 stented: 11 Epic, 13 Magna, 20 Mosaic; 4 stentless: 2 Freestyle, 1 Toronto, 1 Solo) underwent TTE and 64-slice MDCT on the same day. MDCT acquisitions were obtained using a multisegment algorithm allowing for a temporal resolution between 52 to 210 ms, depending on heart rate. EOA was quantified by TTE using the continuity equation and by 64-slice MDCT using manual planimetry of the anatomical orifice. MDCT planimetry was feasible in 44 patients (91.6%). Bioprosthetic alloy artefacts precluded adequate visualization of the leaflets in 4 patients. EOAs by MDCT and TTE were highly correlated (r=0.924; p<0.0001) and not significantly different from each other (1.15 ± 0.28 vs 1.10 ± 0.30 cm2, p=ns). Interobserver reproducibility, assessed in 20 pts, was excellent (ICC 0.92; p<0.0001) without significant bias (−0.029 ± 0.1 cm2). 64- MDCT is highly accurate and reproducible in the evaluation of aortic biosprothetic EOA and can therefore represent an interesting alternative to TTE in pts with poor acoustic windows.