Normal diameter of the ascending aorta in adults: the impact of stricter criteria on selection of subjects free of disease

BACKGROUND: The American Society of Echocardiography 2015 guidelines for measurement of the aorta utilized studies, including one by Devereaux et al., that suffered from smaller sample sizes and lax criteria for selection of normal subjects, using absence of clinical etiologies of aortic aneurysm without consideration of echocardiographic normalcy. This study was carried out to determine the normal dimension of the ascending thoracic aorta in a large population using stricter selection criteria. METHODS: Echocardiographic studies of patients ≥15 years of age performed at a large tertiary care hospital over the last four years were retrospectively evaluated. Only those who did not fulfill any of the 28 causes of aortic dilatation, as defined by AHA 2010 guidelines, either in their clinical records or echocardiograms were included as “normal subjects.” The dimensions of the mid-ascending thoracic aorta were measured by standardized echocardiography in a plane perpendicular to that of the long axis of the aorta, at end-diastole, using leading edge–to–leading edge technique. RESULTS: Out of 3,201 normal subjects, 974 were men and 2,227 were women. The mean age was 37.91±14.94 years. The mean diameter of the ascending aorta (Asc Ao) in men was 2.91±0.40 cm, compared with 3.34±0.34 cm in prior studies. The mean diameter of Asc Ao in women was 2.70±0.36 cm, compared with 2.98±0.34 cm in prior studies. CONCLUSIONS: These data suggest that in a larger population with more stringent criteria for normalcy, the prevalence of dilated aorta will be higher than those suggested by the current guidelines, if the suggested cutoffs are applied