N Chatrath, R Bhatia, S Fyyaz, J Forster, S Marwaha, C Scrocco, N Jayaratne, B Ensam, E Androulakis, S Al-Turaihi, S Sharma, M Tome Esteban, M Papadakis. 09 November 2023. Read paper here
Background: Aortic size varies between individuals and is influenced by age, gender, body size and blood pressure. There are numerous studies aimed at defining normative aortic root measurements, but the vast majority of these are in older adults, or limited by a small sample size.
Purpose: To screen a large number of young individuals (≤35 years) to understand the rate of aortic growth, validate current guideline cut-offs for aortic root measurements in this age group and compare findings in males versus females.
Methods: Individuals ≥ 16 years old who attended a voluntary, nationwide cardiac screening programme for young individuals (aged 14-35) were offered and consented for an additional focused transthoracic echocardiogram of the aorta. Individuals with a known cardiac abnormality or genetic syndrome (for example Marfan’s) were excluded. Images were obtained in the parasternal long axis view with measurements of the sinus of Valsalva (SOV), sinotubular junction (STJ) and ascending aorta (AA) at end-diastole from inner-edge to inner-edge in line with British Society of Echocardiography (BSE) guidance. Measurements were indexed to height (in metres). Mean SOV, STJ and AA measurements were plotted against age and comparisons were made between males and females.
Results: 1153 patients were recruited. 11 were excluded to a bicuspid aortic valve (BAV), leaving 1142 subjects in the final analysis. 88% (1004) were Caucasian. The aortic measurements are shown in table 1. Males had a significantly larger SOV, STJ and AA than females (p<0.001). However, when indexed to height, only the SOV was significantly larger. All mean aortic root measurements fell within the normative range for each gender as specified by current BSE guidance.
Mean aortic root measurements at each year of age are shown in figure 1. There was a weakly positive correlation coefficient between age and aortic diameter (r=0.33 at SOV, r=0.31 at STJ, r=0.39 at AA) which, coupled with the lines of best-fit in figure 1, suggest there is slow but continual aortic growth from the age of 16.
Conclusion: Despite adult height being reached by the age of 16 in most individuals, the aorta continues to grow beyond this age. This study further highlights the importance of indexing aortic measurements to height, and validates that the current BSE guideline cut-offs for aortic root measurements can be applied to young individuals.