Anatomically Normal Aortic Valve Area in Relation to Age, Sex, Body Size, and Aortic Root Dimensions: A TEE Study

Aortic valve area (AVA) is used to assess aortic stenosis severity, yet normal reference values remain poorly defined, partly owing to technical limitations with two-dimensional echocardiography. We aim to characterize AVA using three-dimensional transesophageal echocardiography (3D TEE) in patients with non-calcified aortic valves (AV) and to clarify its associations with age, sex, body surface area (BSA), and aortic root geometry. We retrospectively analyzed the data of 239 Japanese adults (mean age, 66 years; 27% women) without AV or root diseases. Anatomically normal AVA was quantified by 3D planimetry during early systole. The median AVA was 3.2 cm² and was significantly associated with age, sex, and BSA. AVA was smaller in women than in men (2.7 vs 3.4 cm², p <0.001), even after adjusting for BSA. AVA remained largely unchanged with age in women but declined significantly with aging in men. Similar trends were observed in annular areas, except for a modest reduction in older women. Consequently, the AVA-to-annulus area ratio was higher in women (0.79 vs 0.76). AVA correlated most strongly with annular area (R = 0.69), followed by sinus of Valsalva diameter (R = 0.60) and sinotubular junction area (R = 0.50) (all p <0.001). A multivariate model adjusted for age, sex, stroke volume, and annular area explained AVA well (adjusted R² = 0.66), whereas substituting BSA for annular area markedly reduced explanatory power (adjusted R² = 0.42). Annular area may be a key determinant of anatomically normal AVA. Indexing AVA to annular area, rather than BSA, may provide a more accurate assessment of aortic stenosis severity.