Abdominal aortic aneurysm is a progressive condition with an increased risk of aortic dissection and mortality [8, 14]. In this study, our results indicate that 2D-TTE imaging is comparable to CT methodology for measuring and estimating ascending aorta diameters during routine echocardiographic examination. Routine 2D-TTE procedures include, but are not limited to, initial and supplemental tests, evaluation of end organ damage (e.g.: hypertension, diabetes mellitus), evaluation of cardiac and aortic structure and function (e.g.: left atrial appendage, left ventricular hypertrophy and diastolic dysfunction, prosthetic heart valves, paravalvular abscesses, patients on ventilators, or with chest wall injuries), intraoperative TTE, guidance of transcatheter procedures (e.g.: septal defect closure, or atrial appendage obliteration, transcatheter valve procedures), and critically ill patients [15]. In addition, we show that patients aged over 75, primarily non-smokers, without known valvular diseases or hemodynamic compromise, but with increased proximal (tubular) ascending aorta (D diameter) during routine echocardiographic measurements, may present with silent AAA. In fact, an increased proximal (tubular) ascending aorta (D diameter) represents an independent predictor of a silent AAA with a threshold of ≥33 mm or ≥ 19 mm/m2. We hypothesized that in larger prospective studies, the B diameter can also become significantly dilated. Conversely, the fibrous portion of the A and C diameters, can mask progression of the dilatation in those areas.
The abdominal aorta can be relatively easily visualized to the left of the inferior vena cava in sagittal (superior–inferior) subcostal views [16]. Although, 2D-TTE transducers are not optimal for aneurysm detection, detection of an abnormal abdominal aorta can prompt further imaging studies to confirm the presence of AAA. Upon finding of abnormal ascending aorta indices, we recommend screening of the abdominal aorta by means of 2D-TTE, as show to be feasible with minimal additional time and cost compared to separate abdominal ultrasound examination [16, 17]. Our recommendation extends the current guidelines which recommend 1-time screening for AAA with ultrasonography in men aged 65 to 75 years who have ever smoked [6].
Interestingly, patients with diabetes may have a lower incidence of abdominal aortic aneurysm, although the link between diabetes and AAA development and expansion is unclear [18, 19]. In our study, we observed a significant number of diabetic patients in the AAA group compared to the control group (no AAA group). This seemingly opposing results can be explained by the fact we did not include within the aims of the study the evaluation of diabetes, hence, patient stratification was not addressed towards that end. To conclude, routine 2D-TTE examination of the ascending aorta is a rapid, accurate and cost-effective tool to identify a ‘silent’ high-risk AAA population for which further evaluation may be beneficial [17, 20]. These are particularly relevant when screening for AAA may be overlooked, or screening programs with ultrasonography may not be fully implemented [6, 21]. Clinical awareness, and performance of comprehensive echocardiographic analysis, can help in early diagnosis to reduce AAA-associated risks, reduce mortality and morbidity as well as the economic burden. The limitations of the present study are its non-randomized, retrospective observational design and the limited number of patients. Selection bias is a limitation of the studies included in the analysis. A larger prospective study must be conducted to monitor and determine the presence of AAA in patients with isolated dilated ascending aorta without any associated cardiovascular complications.