Ethical approval was received from the local ethical committee of the University. All steps of study were conducted according to the principles of the Helsinki Declaration and in adherence to the local guidelines for good clinical practice. The patients, who were newly diagnosed with isolated ascending aorta dilatation without any complications, were included to the study. Exclusion criteria were determined as follows: accompanying cardiac disease, valve disease in echocardiogram, bicuspid aorta, vascular operation history, peripheral vascular disease, pulmonary embolism, pulmonary infection, chronic obstructive lung disease and already known hereditary or immune disease and drug usage history resulting from any chronic disease. Individuals were selected from recorded computed tomography scans used to diagnose AA incidentally.
Patient selection and group creation
This study is a non-randomized controlled trial. The population of this study consists of patients incidentally diagnosed ascending AA patients without any complaints in routine control. To estimate sample collection with Gpower 3.1.9.4 program was used. It was done by power analysis using software. The power value detection of left ventricular ejection fraction (LVEF) was made by depending on the reference article [6].
Echocardiographic findings and Computed tomography (CT) angiography records were scanned retrospectively. After preparing a participant pool from the tomography records, initially unsuitable individuals were excluded to the study, in accordance with the exclusion criteria. The patients with isolated ascending aorta dilatation were designated as the study group (n: 85) and individuals who had normal aorta diameters were designated as the control group (n: 85). Ascending aorta diameters, thorax diameters, left and right lung volumes and cardiac volumes were measured in CT angiograms from all participants.
Computed tomography measurements
CT angiography scans were done by 16-detector CT device (Toshiba Alexion™/Advance, Toshiba Medical Systems Corporation Nashu, Japan). The thoracic structures were evaluated at 1 mm thickness, 120 kVp, 50–65 mAs, 0.938 pitch, 0.75 s rotation time, 16 × 1 collimation, matrix 512 × 512 and 250 × 300 mm FOV. Three dimensional (3D) multiplanar image reformation and maximum density projections were performed by on a radiology workstation (Sectra Workstation IDS 7, Linköping, Sweden). The morphological parameters such as the diameter of the ascending aorta, cardiac volume and thorax diameter were calculated. These calculations were performed on 3D plans by using available software program Intrasense Myrian® (Myrian; Intrasense, Montpellier, France). This application is the process of defining the anatomical structures of the patient, coloring the area of interest and lifting them into three dimensions. In our study, we firstly defined the lung and heart regions on the CT images that we transferred to the Myrian® software, and then we measured the thorax diameter together with the cardiac volume measurement from the program, by making the appropriate coloring (Fig. 1).
Echocardiographic evaluation
Routine echocardiographic evaluations were conducted by an experienced echocardiographer, based on the recommendations of the American Society of Echocardiography and the European Association of Cardiovascular Imaging [7]. All examinations were made by left parasternal approach using a Philips iE33 (S5-1 probe, iE33, Philips Medical Systems, Andover, MA) ultrasound device, with a 3.5-MHz ultrasound probe. The determined left atrial dimension (LAD), left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter (LVDs), left ventricular ejection fraction (LVEF) and the left ventricular posterior wall thickness (LVPWd) values of each patient were recorded.
Statistical analysis
Data were then evaluated and expressed in terms of inter-observer agreement in pairs. The statistical analyses were made with by using a software program (IBM SPSS 22.0). Normal distribution weight analyses were made by evaluating five parameters (kurtosis-skewness, Histogram, Q-Q plots, Std/Mean, Shapiro Wilk Test) from the data obtained. The data that took three points from these five parameters were considered as normally distributed. The Independent Samples T Test was used for binary group analysis as parametric assessment test, the Pearson Correlation test was used for correlation analysis, and the Pearson Chi-Square Test was used for frequency analysis: p < 0.05 was considered as statistically significant.