Linear growth pattern can be used to predict ascending aortic aneurysm growth.

Objectives. Current guidelines recommend that surveillance imaging should be performed at least every third year for patients with ascending thoracic aortic aneurysm (ATAA) even though such aneurysms' growth rate is mostly minimal. The purpose of this study was to clarify the pattern of the growth of ATAAs in a real-life patient population to adjust the optimal timing of aortic surveillance for each patient. Methods. This study includes patients (n = 209) who had been followed due to ATAA in the central hospital of North Karelia in Eastern Finland between years 2007 and 2023. Aortic imaging was performed using either computed tomography (CT) or transthoracic echocardiography (TTE). In the CT images, the aortic dimensions were measured according to guidelines in four levels of the ascending aorta. TTE measurements were collected from medical records. Measurements were used to explore the pattern of the ATAA growth. Results. During the mean surveillance time 5.0 ± 3.5 years, the median growth rate of ATAAs was 0.37 mm/year. One fifth (21.5%) of the aneurysms showed no expansion during the follow-up. Despite the minimal growth rate during surveillance, some patients ended up exceeding the cut-off for preventive surgery. Among the patients, who showed expansion during the follow-up, the linear model seemed to best describe the growth of ATAA. Conclusions. The majority of the patients had a very low ATAA growth rate. Based on this study, the growth of ATAAs could be described using a linear model, which could, in turn, be used to predict the growth of an aneurysm.