Screening for Abdominal Aortic Aneurysm During Transthoracic Echocardiography: A Systematic Review and Meta-analysis

Editor's Choice -- European Society for Vascular Surgery (ESVS) 2024 Clinical Practice Guidelines on the Management of Abdominal Aorto-Iliac Artery Aneurysms

OBJECTIVE

The European Society for Vascular Surgery (ESVS) has developed clinical practice guidelines for the care of patients with aneurysms of the abdominal aorta and iliac arteries in succession to the 2011 and 2019 versions, with the aim of assisting physicians and patients in selecting the best management strategy.

METHODS

The guideline is based on scientific evidence completed with expert opinion on the matter. By summarising and evaluating the best available evidence, recommendations for the evaluation and treatment of patients have been formulated. The recommendations are graded according to a modified European Society of Cardiology grading system, where the strength (class) of each recommendation is graded from I to III and the letters A to C mark the level of evidence.

RESULTS

A total of 160 recommendations have been issued on the following topics: Service standards, including surgical volume and training; Epidemiology, diagnosis, and screening; Management of patients with small abdominal aortic aneurysm (AAA), including surveillance, cardiovascular risk reduction, and indication for repair; Elective AAA repair, including operative risk assessment, open and endovascular repair, and early complications; Ruptured and symptomatic AAA, including peri-operative management, such as permissive hypotension and use of aortic occlusion balloon, open and endovascular repair, and early complications, such as abdominal compartment syndrome and colonic ischaemia; Long term outcome and follow up after AAA repair, including graft infection, endoleaks and follow up routines; Management of complex AAA, including open and endovascular repair; Management of iliac artery aneurysm, including indication for repair and open and endovascular repair; and Miscellaneous aortic problems, including mycotic, inflammatory, and saccular aortic aneurysm. In addition, Shared decision making is being addressed, with supporting information for patients, and Unresolved issues are discussed.

CONCLUSION

The ESVS Clinical Practice Guidelines provide the most comprehensive, up to date, and unbiased advice to clinicians and patients on the management of abdominal aorto-iliac artery aneurysms.

The Fate of Patients Opportunistically Screened for Abdominal Aortic Aneurysms During Echocardiogram or Arterial Duplex Scans

OBJECTIVE

To evaluate the long term outcomes of individuals who attended for transthoracic echocardiograms (TTEs) or lower limb arterial duplex scans (LLADS) and were opportunistically screened for abdominal aortic aneurysms (AAA).

METHODS

Follow up of a prospective single centre pilot cohort study conducted between December 2012 and September 2014 at a tertiary vascular centre in the United Kingdom. Men and Women aged 65 and over were invited to undergo AAA screening when attending hospital for TTE or LLADS. Screening was performed by ultrasonographic examination of the abdomen at the end of their planned scans. AAA was defined as an abdominal aorta outer wall to outer wall anteroposterior diameter of 30 mm or more. Patients were excluded if they had a known AAA or previous abdominal aorta intervention. Follow up outcomes were evaluated in December 2020.

RESULTS

762 patients were enrolled in this study; 486 had TTE and 276 patients had LLADS. The overall incidence of AAA was 54 (7.1%) in the combined cohort, 25 (5.1%) in the TTE group, and 29 (10.5%) in the LLADS group. After a median 7.6 years, two of the 54 AAAs received intervention in the form of endovascular repair. Three others reached treatment threshold but were managed conservatively. The overall intervention rate was 3.7% of detected AAAs. Adjusted mortality rates in those with AAA vs. without was 64.8% and 36%, respectively (hazard ratio [HR] 2.02, p < .001). Diabetes (HR 1.35, p = .015) and older age (HR 1.18, p = .17) were the other factors associated with death.

CONCLUSION

AAA is associated with a significantly increased mortality rate. Populations attending hospital for TTE or LLADS demonstrate a higher prevalence of AAA than population based screening; however, the proportion offered AAA intervention was low. Further research into opportunistic screening should target those more likely to undergo AAA repair, unless other interventions are demonstrated, to reduce the general increased mortality in AAA patients.

Recent technologies in cardiac imaging

Cardiac imaging allows physicians to view the structure and function of the heart to detect various heart abnormalities, ranging from inefficiencies in contraction, regulation of volumetric input and output of blood, deficits in valve function and structure, accumulation of plaque in arteries, and more. Commonly used cardiovascular imaging techniques include x-ray, computed tomography (CT), magnetic resonance imaging (MRI), echocardiogram, and positron emission tomography (PET)/single-photon emission computed tomography (SPECT). More recently, even more tools are at our disposal for investigating the heart's physiology, performance, structure, and function due to technological advancements. This review study summarizes cardiac imaging techniques with a particular interest in MRI and CT, noting each tool's origin, benefits, downfalls, clinical application, and advancement of cardiac imaging in the near future.

Peptide Amphiphile Supramolecular Nanofibers Designed to Target Abdominal Aortic Aneurysms

An abdominal aortic aneurysm (AAA) is a localized dilation of the aorta located in the abdomen that poses a severe risk of death when ruptured. The cause of AAA is not fully understood, but degradation of medial elastin due to elastolytic matrix metalloproteinases is a key step leading to aortic dilation. Current therapeutic interventions are limited to surgical repair to prevent catastrophic rupture. Here, we report the development of injectable supramolecular nanofibers using peptide amphiphile molecules designed to localize to AAA by targeting fragmented elastin, matrix metalloproteinase 2 (MMP-2), and membrane type 1 matrix metalloproteinase. We designed four targeting peptide sequences from X-ray crystallographic data and incorporated them into PA molecules via solid phase peptide synthesis. After coassembling targeted and diluent PAs at different molar ratios, we assessed their ability to form nanofibers using transmission electron microscopy and to localize to AAA in male and female Sprague-Dawley rats using light sheet fluorescence microscopy. We found that three formulations of the PA nanofibers were able to localize to AAA tissue, but the MMP-2 targeting PA substantially outperformed the other nanofibers. Additionally, we demonstrated that the MMP-2 targeting PA nanofibers had an optimal dose of 5 mg (∼12 mg/kg). Our results show that there was not a significant difference in targeting between male and female Sprague-Dawley rats. Given the ability of the MMP-2 targeting PA nanofiber to localize to AAA tissue, future studies will investigate potential diagnostic and targeted drug delivery applications for AAA.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

Despite declining incidence and mortality rates in many countries, the abdominal aortic aneurysm (AAA) continues to represent a life-threatening cardiovascular condition with an overall prevalence of about 2-3% in the industrialized world. While the risk of AAA development is considerably higher for men of advanced age with a history of smoking, screening programs serve to detect the often asymptomatic condition and prevent aortic rupture with an associated death rate of up to 80%. This review summarizes the current knowledge on identified risk factors, the multifactorial process of pathogenesis, as well as the latest advances in medical treatment and surgical repair to provide a perspective for AAA management.

Ultrasound Imaging of the Abdominal Aorta: A Comprehensive Review

Ultrasound is the imaging modality of choice for the initial evaluation of disorders that involve the abdominal aorta (AA). The diagnostic value of ultrasound resides in its ability to allow assessment of the anatomy and structure of the AA using two- dimensional, three-dimensional, and contrast-enhanced imaging. Moreover, ultrasound permits evaluation of the physiologic and hemodynamic consequences of abnormalities through Doppler interrogation of blood flow, thus enabling the identification and quantification of disorders within the AA and beyond its boundaries. The approach to ultrasound imaging of the AA varies, depending on the purpose of the study and whether it is performed in a radiology or vascular laboratory or in an echocardiography laboratory. The aim of this review is to demonstrate the usefulness of ultrasound imaging for the detection and evaluation of disorders that involve the AA, detail the abnormalities that are detected or further assessed, and outline its value for echocardiographers, sonographers, and radiologists.

Appraisal of transthoracic echocardiography for opportunistic screening of abdominal aortic aneurysm

ABSTRACT

Abdominal aortic aneurysm is a life threatening disease. Most of the patients diagnosed incidentally because of the asymptomatic nature of this disease. This study aimed to determine the frequency of abdominal aortic aneurysm and evaluate the value of opportunistic screening during transthoracic echocardiography.A total of 5138 patients referred for echocardiographic evaluation for any reason were screened for abdominal aortic aneurysm between November 2014 to July 2019. The aneurysm was defined as an abdominal aorta with a diameter greater than 30 mm, or segmental dilatation of more than 50% of its size in non-dilated parts.The overall frequency of abdominal aortic aneurysm was 2.2% (n = 109) in the study population. Male sex (P < .001), older age (P < .001), presence of diastolic dysfunction (P = .036), hypertension (P < .001), coronary artery disease (P < .001), and hyperlipidemia (P < .001) were associated with abdominal aortic aneurysm. Patients with aneurysm had significantly increased diameters of the aortic trunk (P < .001) and ascending aorta (P < .001), significantly thicker interventricular septum (P < .001) and posterior wall (P < .001), significantly increased end-diastolic diameter (P < .001) and enlarged left atrium (P < .001), and significantly decreased ejection fraction (P < .001). The mostly met criteria for screening abdominal aortic aneurysm in international guidelines was the age of the patients.Based on the results of this study, screening patients over 60 years of age who undergo a transthoracic echocardiography for any reason would be beneficial to detect an asymptomatic abdominal aortic aneurysm in Turkish population.

ACR Appropriateness Criteria® Nontraumatic Aortic Disease

Nontraumatic aortic disease can be caused by a wide variety of disorders including congenital, inflammatory, infectious, metabolic, neoplastic, and degenerative processes. Imaging examinations such as radiography, ultrasound, echocardiography, catheter-based angiography, CT, MRI, and nuclear medicine examinations are essential for diagnosis, treatment planning, and assessment of therapeutic response. Depending upon the clinical scenario, each of these modalities has strengths and weaknesses. Whenever possible, the selection of a diagnostic imaging examination should be based upon the best available evidence. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment. The purpose of this document is to assist physicians select the most appropriate diagnostic imaging examination for nontraumatic aortic diseases.

Isolated ascending aorta dilatation is associated with increased risk of abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) is an asymptomatic condition characterized by progressive dilatation of the aorta. The purpose of this study is to identify important 2D-TTE aortic indices associated with AAA as predictive tools for undiagnosed AAA.

Methods

In this retrospective study, we evaluated the size of the ascending aorta in patients without known valvular diseases or hemodynamic compromise as predictive tool for undiagnosed AAA. We studied the tubular ascending aorta of 170 patients by 2-dimensional transthoracic echocardiography (2D-TTE). Patients were further divided into two groups, 70 patients with AAA and 100 patients without AAA with normal imaging results.

Results

Dilatation of tubular ascending aorta was measured in patients with AAA compared to the group with absent AAA (37.5 ± 4.8 mm vs. 31.2 ± 3.6 mm, p < 0.001, respectively) and confirmed by computed tomographic (CT) (35.6 ± 5.1 mm vs. 30.8 ± 3.7 mm, p < 0.001, respectively). An increase in tubular ascending aorta size was associated with the presence of AAA by both 2D-TTE and CT (r = 0.40, p < 0.001 and r = 0.37, p < 0.001, respectively). The tubular ascending aorta (D diameter) size of ≥33 mm or ≥ 19 mm/m² presented with 2–4 times more risk of AAA presence (OR 4.68, CI 2.18–10.25, p = 0.001 or OR 2.63, CI 1.21–5.62, p = 0.02, respectively). In addition, multiple logistic regression analysis identified tubular ascending aorta (OR 1.46, p < 0.001), age (OR 1.09, p = 0.013), gender (OR 0.12, p = 0.002), and LVESD (OR 1.24, p = 0.009) as independent risk factors of AAA presence.

Conclusions

An increased tubular ascending aortic diameter, measured by 2D-TTE, is associated with the presence of AAA. Routine 2D-TTE screening for silent AAA by means of ascending aorta analysis, may appear useful especially in older patients with a dilated tubular ascending aorta (≥33 mm).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01488-w.

[Opportunistic screening for abdominal aortic aneurysm during echocardiography in patients with coronary artery disease: Utility or futility?]

Abdominal aortic aneurysm is a chronic degenerative disease that is usually silent until rupture occurs and this complication is still associated in contemporary era with a high rate of mortality. Screening programmes for abdominal aortic aneurysm have been shown to be effective in reducing global mortality in the screened population but these programmes are poorly implemented in the Western countries. As coronary artery disease and abdominal aorta aneurysmal disease share many risk factors, the cardiologist is centrally positioned in the screening strategy, not only to identify patients with higher risk of developing abdominal aortic aneurysm, but also to perform an opportunistic screening during echocardiography. This paper summarises evidence about the feasibility, indications, modalities, benefits and risks related to the opportunistic screening for abdominal aortic aneurysm during echocardiography with a particular emphasis on the population of patients with coronary artery disease.

Bazedoxifene Attenuates Abdominal Aortic Aneurysm Formation via Downregulation of Interleukin-6/Glycoprotein 130/Signal Transducer and Activator of Transcription 3 Signaling Pathway in Apolipoprotein E-Knockout Mice

Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease characterized by aortic dilatation and predominantly affects an elderly population. Accumulating evidence suggests that Interleukin-6 (IL-6) and the signal transducer and activator of transcription 3 (STAT3) play an important role in formation of AAAs. However, it remains unclear whether Bazedoxifene (BAZ) could suppress the activation of IL-6/GP130/STAT3 in vascular cells and the formation of AAA. Here we explored the effect of BAZ on AngII-stimulated AAA formation. ApoE^–/– mice infused with AngII for 28 days using osmotic minipumps were treated with placebo or 5mg/kg BAZ. In our results most of the AngII-induced mice developed AAA with exacerbated inflammation, degradation of elastin fibers, STAT3 phosphorylation, and increased expression of matrix metalloproteinases (MMPs). These effects were markedly attenuated by BAZ. Furthermore, BAZ suppressed the stimuli-induced (IL-6 or AngII) expression of P-STAT3, MMP2 and MMP9 in vascular smooth muscle cells (VSMCs). BAZ inhibited wound healing, colony formation and suppressed STAT3 nuclear translocation in vitro. In conclusion, these results indicated that BAZ downregulated IL-6/GP130/STAT3 signaling and interfered with AAA formation induced by AngII in ApoE^–/– mice, which indicates a novel potential strategy for the prevention and therapy of AAA.

Prevalence and Prediction of Aneurysmal Dilatation of the Abdominal Aorta in Koreans: Results of Screening During Transthoracic Echocardiographic Examination

BACKGROUND

Aortic aneurysm (AA) is an enlargement of the aorta to greater than 1.5 times normal size. Although the US guideline recommends ultrasound screening for abdominal AA (AAA) in men older than 65 years regardless of symptoms, limited data describe the prevalence of AAA in Korea. In this study, we screened patients for AAA during transthoracic echocardiographic examination (TTE).

METHODS

We screened for AAA in all consecutive subjects older than 60 years who underwent TTE. We defined AAA as an abdominal aorta with the diameter greater than 30 mm.

RESULTS

We analyzed 5,679 persons (2,272 females, 74 ± 8 years old). The mean size of the abdominal aorta was 19.0 ± 6.1 mm. The prevalence of AAA was 2.9% (165/5,679) and was significantly higher in males (4.7% vs. 1.1%, p < 0.001). AAA was significantly associated with male sex (odds ratio [OR] = 3.098, 95% confidence interval [CI] = 1.971-4.870, p < 0.001), older age (OR = 1.074, 95% CI = 1.050-1.097, p < 0.001), non-diabetes (OR = 1.886, 95% CI = 1.264-2.813, p < 0.001), dyslipidemia (OR = 1.475, 95% CI = 1.019-2.135, p = 0.040), ever-smoker (OR = 2.090, 95% CI = 1.448-3.015, p < 0.001), chronic kidney disease (CKD, OR = 1.757, 95% CI = 1.182-2.612, p = 0.005), and coronary artery disease (CAD, OR = 2.452, 95% CI = 1.742-3.451, p < 0.001). A prediction score with a multivariate model (range: 3.34-10.51) detected AAA with a sensitivity of 79.4% and a specificity of 66.8% with a reference value > 6.8 (area under the curve = 0.799).

CONCLUSIONS

In Korea, the prevalence of AAA was 2.9% in subjects older than 60 years during TTE, and AAA was significantly associated with older age, male sex, non-diabetes, dyslipidemia, ever-smoker, CKD, and CAD. Prediction score (> 6.8%) detected AAA with a sensitivity of 79.4% and a specificity of 66.8%.

miR-33-5p knockdown attenuates abdominal aortic aneurysm progression via promoting target adenosine triphosphate-binding cassette transporter A1 expression and activating the PI3K/Akt signaling pathway

PURPOSE

The aim of this study was to investigate the role of miR-33-5p in abdominal aortic aneurysm progression, which regulated adenosine triphosphate-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux and lipid accumulation in THP-1 macrophage-derived foam cells through the PI3K/Akt pathway.

METHODS

Quantitative reverse transcription polymerase chain reaction was used to evaluate the expression level of miR-33-5p and ABCA1 mRNA in abdominal aortic aneurysm patient and normal person tissues. The relationship between miR-33-5p and ABCA1 was examined by dual luciferase report assay. High-performance liquid chromatography was used to evaluate the levels of cholesterol contents. Cholesterol efflux detection was performed by liquid scintillator. The expression of inflammatory cytokines was detected by quantitative reverse transcription polymerase chain reaction. Western blot was applied to determine the expression levels of ABCA1, PI3K (p-PI3K), and Akt (p-Akt).

RESULTS

The quantitative reverse transcription polymerase chain reaction analysis results revealed miR-33-5p overexpression in abdominal aortic aneurysm tissues, but the expression level of ABCA1 was lower in abdominal aortic aneurysm tissues than non-abdominal aortic aneurysm tissues. Subsequently, the dual luciferase report gene assay confirmed that ABCA1 was a target of miR-33-5p, and miR-33-5p-negative regulated ABCA1 expression. Moreover, the expression levels of p-PI3K, p-Akt, and ABCA1 were decreased in THP-1 cell transferred with ABCA1 siRNA, but knockdown of miR-33-5p had an opposite effect. Furthermore, knockdown of miR-33-5p decreased the expression of MMP-2, MMP-9, TNF-α, total cellular cholesterol, and promoted cholesterol efflux in THP-1-derived foam cells. Importantly, LY294002 (PI3K inhibitor) or si-ABCA1 completely inhibited the stimulatory effects of miR-33-5p inhibitor.

CONCLUSION

This study has found that knockdown of miR-33-5p induced ABCA1 expression and promoted inflammatory cytokines and cholesterol efflux likely via activating the PI3K/Akt signaling pathway.

Usefulness of Screening for Abdominal Aortic Aneurysm During Transthoracic Echocardiography in Women ≥50 Years of Age

Usefulness of screening for abdominal aortic aneurysm (AAA) during transthoracic echocardiography (TTE) in women is uncertain. The aim of the present study was to clarify the clinical usefulness of screening for AAA during TTE and to identify important TTE indices associated with AAA in women in a routine clinical setting. We prospectively studied 1,495 women (≥50 years) referred for TTE. AAA was defined as ≥30 mm in size. The additional screening time for AAA was <1 minute. The abdominal aorta was visualized in 95.1 % (1,422 of 1,495) using the same TTE probe. AAA was identified in 1.9% (27 of 1422). The aortic root size was larger in patients with AAA than those without (33.3 ± 3.2 vs 30.5 ± 3.4 mm, p < 0.001). The aortic root size had a correlation with abdominal aortic size (r = 0.22, p < 0.001). The aortic root size of ≥30.3 mm was predictive of AAA (area under the curve = 0.74, p < 0.001) and all patients with AAA had the aortic root size of ≥28.0 mm. Multiple logistic regression analysis revealed that the aortic root size (Odds ratio 1.17, p = 0.007) was a most independent TTE index of AAA. In conclusion, the visibility of the abdominal aorta using TTE probe was excellent. When the aortic root size is ≥28.0 mm during TTE in women ≥50 years of age, screening for AAA should be carried out.