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 AVAADCT and AVA3DTEE (r = 0.83, P < 0.001) and a somewhat lower correlation between AVAADCT and AVA2DTEE (r = 0.63, P = 0.006). In the tricuspid AS group, both AVA2DTEE and AVA3DTEE significantly correlated with AVACE (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 3D TEE is useful for assessing anatomical AVA regardless of aortic-valve morphology.