Indexed aortic valve area using multimodality imaging for assessing the severity of bicuspid aortic stenosis.

Background: The impact of various imaging modalities on discordance/concordance between indexed aortic valve area (iAVA) and catheterization-derived mean transaortic pressure gradient (mPG _cath ) is unclear in patients with bicuspid aortic valve (BAV). This study aimed to compare iAVA measurements obtained using four different methodologies in BAV and tricuspid aortic valve (TAV) patients, using mPG _cath as a reference standard.
Methods: We retrospectively reviewed patients who underwent comprehensive assessment of AS, including two-dimensional (2D) transthoracic echocardiography (TTE), three-dimensional (3D) transesophageal echocardiography (TEE), multidetector computed tomography (MDCT), and catheterization, at our institution between 2019 and 2022. iAVA was measured using the continuity eq. (CE) with left ventricular outflow tract area obtained by 2D TTE, 3D TEE, and MDCT, as well as planimetric 3D TEE.
Results and Conclusions: Among 564 patients (64 with BAV and 500 with TAV), 64 propensity-matched pairs of patients with BAV and TAV were analyzed. iAVA _CE(2DTTE) led to overestimation of AS severity (BAV, 23.4%; TAV, 28.1%) and iAVA _CE(MDCT) led to underestimation of AS severity (BAV, 29.3%; TAV, 16.7%), whereas iAVA _CE(3DTEE) and iAVA _Plani(3DTEE) resulted in a reduction in the discordance of AS grading. A moderate correlation was observed between mPG _cath and iAVA _CE(3DTEE) (BAV, r = -0.63; TAV, r = -0.68), with iAVA _CE(3DTEE) corresponding to the current guidelines' cutoff value (BAV, 0.58 cm ² /m ² ; TAV, 0.60 cm ² /m ² ). Discordance/concordance between iAVA and mPG _cath in evaluating AS severity varies depending on the methodology and imaging modality used. The use of iAVA _CE(3DTEE) is valuable for reconciling the discordant AS grading in BAV patients as well as TAV.
Competing Interests: Declaration of competing interest All authors have no conflicts of interest to declare. The following are the supplementary data related to this article. Supplementary data to this article can be found online at https://doi.org/10.1016/j.ijcard.2024.132416.
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