Aortic valve area assessed with 320-detector computed tomography: comparison with transthoracic echocardiography

To evaluate the diagnostic accuracy of aortic valve area (AVA) assessment with 320-detector Computed Tomography (MDCT) compared to transthoracic echocardiography (TTE) in a population with mild to severe aortic valve stenosis. AVA was estimated in 169 patients by planimetry on MDCT images (AVAMDCT) and by the continuity equation with TTE (AVATTE). To generate a reference AVA (AVAREF) we used the stroke volume from MDCT divided by the velocity time integral from CW Doppler by TTE (according to the continuity equation: stroke volume in LVOT = stroke volume passing the aortic valve). AVAREF was used as the reference to compare both measures against, since it bypasses the assumption of LVOT being circular in the continuity equation and the potential placement error of PW Doppler in the LVOT. The mean (±SD) age of the patients was 71 (±9) years, 113 (67 %) were males. Mean AVATTE was 0.93 (±0.33) cm(2), mean AVAMDCT was 0.99 (±0.36) cm(2) and mean AVAREF was 1.00 (±0.39) cm(2). The mean difference between AVATTE and AVAMDCT was -0.06 cm(2), p = 0.001, mean difference between AVATTE and AVAREF was -0.06 cm(2), p