OPTIMIZING CARDIAC MEASUREMENTS Effects of Aging and Body Size on Proximal and Ascending Aorta and Aortic Arch: Inner Edge–to–Inner Edge Reference Values in a Large Adult Population by Two-Dimensional Transthoracic Echocardiography Oana Mirea, MD, Francesco Maffessanti, PhD, Paola Gripari, MD, Gloria Tamborini, MD, Manuela Muratori, MD, Laura Fusini, MS, Cefal u Claudia, MD, Cesare Fiorentini, MD, Iancu Emil Plesea, MD, PhD, and Mauro Pepi, MD, Milan, Italy; Craiova, Romania Background: Aortic size is known to vary significantly by age and body size and to be an important predictor of cardiovascular diseases. The aim of this study was to determine reference values for proximal thoracic aorta diameters, using the inner edge technique and two-dimensional transthoracic echocardiography. Methods: Diameters of the aortic annulus, sinuses of Valsalva, sinotubular junction, arch, and ascending aorta and the angle of insertion of the aorta were measured in 500 subjects (231 women; mean age, 48 6 18 years) with normal echocardiographic findings, retrospectively enrolled. The relations of age and body size with aortic measurements were investigated using bivariate and multiple linear regressions. Results: Measurements were highly feasible (83% for the aortic arch, 100% for the other segments). All aortic diameters significantly related to age, weight and body surface area, while height was correlated only with annular diameter. In predictive models adjusted for gender, older age was associated with increased aortic diameters (R 2 values ranged from 0.36 for the sinotubular junction to 0.52 for the sinuses of Valsalva). Adjust- ments for height and weight led to significant improvements (R 2 values ranged from 0.43 for the sinotubular junction to 0.58 for the sinuses of Valsalva). Similar correlations were observed for men and women. Angle was found to be dependent only on age and gender. Reproducibility analysis showed good to excellent accordance between repeated measurements. Conclusions: The results of this study show the effect of aging on the proximal thoracic aorta and emphasize the importance of accounting for gender and body size when assessing aortic size. The obtained reference ranges willhelp standardize the assessment of aortic dimensions by applying inner edge convention and facilitate comparisons with other imaging techniques. (J Am Soc Echocardiogr 2013;26:419-27.) Keywords: Two-dimensional transthoracic echocardiography, Thoracic aortic diameters, Normative values, Aging Aortic size is known to vary significantly by age and body size 1,2 and to be an important predictor of cardiovascular diseases. 3-5 Therefore, the accurate assessment of aortic size is a key component in guiding clinicaland therapeutic decisions. The establishment of reference rangesand normative equations, taking into account aging and anthropometric data, is of undoubtedimportance in clinical practice fordiagnosis, prognosis, monitoring, and identifying the best timing for surgery. 6 Normal values of proximal aortic diameters and area have been reported using different imaging techniques, from the pioneer studies based on M-mode echocardiography, 7,8 to the more recent ones obtained using cardiac computed tomographic (CT) imaging 1,9 and magneticresonance imaging (MRI). 10 However, the intermodality comparison is limited by sev methodologic discrepancies, including the site of measurement, the considered cardiac phase, and the fact that CT and MRI measure- mentsare made usingthe inneredge–to–inner edge method, whereas echocardiographic studies are mainly based on the le edge convention. Although two-dimensional (2D) transthoracic echocardiographic (TTE) imaging can be used to quantify the inner edge–to–inner edge diameter of the thoracic aorta, available normative range to the leading edge approach, and large series of normal values with the inner edge–to–inner edge method are lacking. Also,the new ul- trasound 2D TTE equipment and transducers allow the accurat uation of the proximal aorta at different levels, and not only of the aortic root. From Centro Cardiologico Monzino IRCCS, Milan,Italy (O.M.,F.M., P.G., G.T., M.M., L.F., C.C., C.F., M.P.); the Departmentof Pathology, Universityof Medicine and Pharmacy, Craiova, Romania (O.M., I.E.P.); and the Department of ClinicalSciences and Community Health, University of Milan, Milan, Italy (C.F.). Reprintrequests:Francesco Maffessanti,PhD, Centro Cardiologico Monzino, IRCCS, Via Parea, 4, 20138 Milan, Italy (E-mail: fmaffessanti@ccfm.it). 0894-7317/$36.00 Copyright 2013 by the American Society of Echocardiography. http://dx.doi.org/10.1016/j.echo.2012.12.013 419