Value of anatomical aortic valve area using real-time three-dimensional transoesophageal echocardiography in patients with aortic stenosis: a comparison between tricuspid and bicuspid aortic valves

Aims Accurate assessment of disease severity is critical for appropriate treatment of patients with aortic stenosis (AS). This study investigated the influence of aortic-valve morphology on the determination of anatomical aortic-valve area (AVA) in patients with AS. Methods and results This prospective study included 126 patients with AS who underwent transoesophageal echocardiography (TEE). Aortic valve area was measured using (i) planimetric two-dimensional (2D) TEE, (ii) volumetric three-dimensional (3D) TEE, and (iii) the continuity equation (CE) obtained with transthoracic echocardiography. Of these, 20 patients also underwent contrast-enhanced multidetector computed tomography (MDCT). Aortic-valve area was measured from multiplanar reconstruction of the MDCT images. Of the 126 patients, 20 (15.9%) were diagnosed with bicuspid AS and 106 were diagnosed with tricuspid AS. There was an excellent correlation between AVA(ADCT) and AVA(3DTEE) (r = 0.83, P < 0.001) and a somewhat lower correlation between AVAADCT and AVA(2DTEE) (r = 0.63, P = 0.006). In the tricuspid AS group, both AVA2DTEE and AVA3DTEE significantly correlated with AVA(CE) (r = 0.63, mean difference 0.13 +/- 0.24 cm(2), and r = 0.83, mean difference 0.03 +/- 0.12 cm(2), respectively, both P < 0.001). In contrast, in the bicuspid AS group, AVA3DTEE significantly correlated with AVACE (r = 0.83, mean difference 0.10 +/- 0.18 cm(2), P < 0.001), whereas AVA2DTEE did not (r = 0.42, mean difference 0.48 +/- 0.32 cm(2), P = 0.066). Conclusion Aortic-valve morphology influenced the assessment of anatomical AVA in patients with AS, and 3DTEE is useful for assessing anatomical AVA regardless of aortic-valve morphology.